POULTRY DISEASES

Highly pathogenic avian influenza (HPAI) A(H5N1) viruses pose a significant economic burden to the poultry industry worldwide and have pandemic potential. Poultry vaccination against HPAI A(H5N1) viruses has been an important component of HPAI control measures and has been performed in Vietnam since 2005. To systematically assess antigenic matching of current vaccines to circulating field variants, we produced a panel of chicken and ferret antisera raised against historical and contemporary Vietnamese reference viruses representing clade variants that were detected between 2001 and 2014. The antisera were used for hemagglutination inhibition (HI) assays to generate data sets for analysis by antigenic cartography, allowing for a direct comparison of results from chicken or ferret antisera. HI antigenic maps, developed with antisera from both hosts, revealed varying patterns of antigenic relationships and clustering of viruses that were dependent on the clade of viruses analyzed. Anti...

Among the many factors that influence the population and composition of gastrointestinal microbiota in monogastric animals, diet is regarded as the most significant factor that animal nutritionists can manipulate to modify the microflora in the digestive systems of these animals. The aim of this review article is to synthesise existing information on the gastrointestinal microbiota of broiler chickens and how they interact with dietary elements to enhance nutrient digestibility and absorption, regulate the immune system, sustain gut health, and ultimately improve the growth performance of broiler chickens. The various microorganisms inhabiting different parts of the digestive tract of avian species and their mechanisms of action have been explored. Additionally, the use of feed additives in broiler diets to influence intestinal microflora, boost the immune response, lower mortality rates, enhance body weight gain, and increase the profitability of broiler production has also been discussed. Several challenges are associated with the use of antibiotics, prebiotics, probiotics, and organic acids as feed additives for disease prevention, growth enhancement, and improving feed conversion ratios in poultry. The incorrect use and excessive reliance on antibiotics can lead to the development of antimicrobial-resistant pathogenic microorganisms and to the accumulation of antibiotic residues in meat products. Organic acids possess astringent odours that can diminish feed palatability, and their excessive use may result in bacteria developing resistance to organic acids. Given these concerns, it is essential to investigate feed ingredients that have similar characteristics to feed additives but do not negatively impact the intestinal microbiome or the host animal in the formulation of broiler feed.

Cystic echinococcosis (CE), caused by Echinococcus granulosus, affects both humans and livestock. Final hosts (dogs) are typically subclinical, while intermediate hosts show symptoms based on cyst location and infection severity. CE is mainly detected in abattoirs via postmortem (PM) examination, making diagnosis challenging and increasing transmission risk. The current study aimed to evaluate the serodiagnosis and statistical significance of using different prepared antigens from cysts against PM method. 170 blood samples were collected from cattle and the separated serum samples were prepared for detection of optical density values by indirect ELISA against different hydatid cysts antigens. The antigens were isolated from various cystic components. Crude hydatid cyst fluid antigen (HCF Ag) was prepared by aspirating fluid from fertile cyst separated from infected organs, centrifuged and aliquoted, laminated layer antigen (LL Ag) obtained by aspirating fluid, separating the laminated layer and homogenized, germinal layer antigen (GL Ag) was isolated through dissection, protoscolices antigen (Pscs Ag) collected, washed with PBS, and all isolates sonicated, and stored at-20°C. Protein concentration was measured using modified Lowry method. The obtained values were statically analyzed. PM prevalence was 11.76%. While ELISA showed 13.5%, with higher prevalence in the liver (7.06%) than lungs (2.35%). Significant differences were noted between antigens, with GL, HCF, and Pscs Ags showing higher values than LL Ag. ELISA diagnostic accuracy was 98.24 % for LL, GL, and Pscs Ags, and 60% for HCF Ag. Our study suggests that GL, HCF, and Pscs Ags were effective and sensitive immunodiagnostic tools for screening hydatosis.

Salmonella enterica serovar Gallinarum is a host-specific serotype that causes the severe systemic disease fowl typhoid in domestic poultry and a narrow range of other avian species but rarely causes disease in mammalian hosts. Specificity of the disease is primarily at the level of the reticuloendothelial system, but few virulence factors have been described other than the requirement for an 85-kb virulence plasmid. In this work, by making functional mutations in the type III secretion systems (TTSS) encoded by Salmonella pathogenicity island 1 (SPI-1) and SPI-2, we investigated the role of these pathogenicity islands in interactions between Salmonella serovar Gallinarum and avian cells in vitro and the role of these pathogenicity islands in virulence in chickens. The SPI-1 mutant showed decreased invasiveness into avian cells in vitro but was unaffected in its ability to persist within chicken macrophages. In contrast the SPI-2 mutant was fully invasive in nonphagocytic cells but ...

Macrophages from inbred chickens that are resistant to salmonellosis show greater and more rapid expression of proinflammatory chemokines and cytokines, including the key Th1-inducing cytokine interleukin-18, upon Salmonella challenge than those from susceptible birds. This suggests the possibility that salmonellosis resistant-line macrophages signal more effectively and rapidly and are more able to induce protective Th1 adaptive responses.

A recent European Union Directive required member states to put monitoring and control programmes in place, of which vaccination is a central component. Live Salmonella vaccines generally confer better protection than killed vaccines, because the former stimulate both cell-mediated and humoral immunity. Administering Salmonella bacteria orally to newly hatched chickens results in extensive gut colonization and a strong adaptive immune stimulus but broiler chickens are immunologically immature. However, colonization exerts a variety of rapid (within 24 h) protective effects. These include specific colonization-inhibition (competitive exclusion) in which the protective bacteria exert a profound resistance to establishment and colonization by other related bacteria. This is thought to be primarily a metabolic attribute of the vaccinating bacteria but may also involve competition for attachment sites. The presence of large numbers of bacteria originating from a live Salmonella vaccine in the intestine can also induce infiltration of polymorphonuclear cells into the intestinal wall, which confers resistance to invasion and systemic spread by virulent Salmonella strains. This opens new perspectives for vaccine usage in broilers, layers and breeding poultry but also in other animals which show increased susceptibility to infection because of their young age or for other reasons, such as oral chemoprophylaxis or chemotherapy, where the lack of established normal gut flora is an issue. We recommend that all live vaccines considered for oral administration should be tested for their ability to induce the two protective effects described above. Further developments in live Salmonella vaccines are, however, currently hindered by fears associated with the use and release of live vaccines which may be genetically modified.

Background: Intensive poultry production systems depend on chemoprophylaxis with anticoccidial drugs to combat infection. A floor-pen study was conducted to evaluate the anticoccidial effect of Artemisia annua and Foeniculum vulgare on Eimeria tenella infection. Five experimental groups were established: negative control (untreated, unchallenged); positive control (untreated, challenged); a group medicated with 125 ppm lasalocid and challenged; a group medicated with A. annua leaf powder at 1.5% in feed and challenged; and a group treated with the mixed oils of A. annua and Foeniculum vulgare in equal parts, 7.5% in water and challenged. The effects of A. annua and oil extract of A. annua + F. vulgare on E. tenella infection were assessed by clinical signs, mortality, fecal oocyst output, faeces, lesion score, weight gain, and feed conversion. Results: Clinical signs were noticed only in three chickens from the lasalocid group, six from the A. annua group, and nine from the A. annua + F. vulgare group, but were present in 19 infected chickens from the positive control group. Bloody diarrhea was registered in only two chickens from A. annua group, but in 17 chickens from the positive control group. Mortality also occurred in the positive control group (7/20). Chickens treated with A. annua had a significant reduction in faecal oocysts (95.6%; P = 0.027) and in lesion score (56.3%; P = 0.005) when compared to the positive control. At the end of experiment, chickens treated with A. annua leaf powder had the highest body weight gain (68.2 g/day), after the negative control group, and the best feed conversion (1.85) among all experimental groups. Conclusions: Our results suggest that A. annua leaf powder (Aa-p), at 1.5% of the daily diet post-infection, can be a valuable alternative for synthetic coccidiostats, such as lasalocid.

Bu çalışmanın amacı, Z Kuşağı bireylerinin kişilik özelliklerinin kariyer değerlerini açıklamadaki etkisini analiz etmektir. Araştırmanın örneklemini, Kayseri ilinde kurulu üniversitelerde öğrenim gören, Z Kuşağı kapsamındaki bireyler oluşturmaktadır. Çalışmada kullanılan veriler, Soto & John (2017) tarafından geliştirilen kısaltılmış “Beş Faktör Kişilik Özellikleri Ölçeği” ve Edgar Schein (1990) tarafından geliştirilen “Kariyer Değerleri Ölçeği” kullanılarak, anket yöntemi ile toplanmıştır. Uygulama neticesinde kullanılabilir 487 adet anket formu elde edilmiştir. Elde edilen veriler, SPSS programı aracılığıyla analiz edilmiştir. Verilerin analiz edilmesinde, geçerlilik ve güvenilirlik, normallik, tanımlayıcı istatistikler, korelasyon ve regresyon testleri kullanılmıştır. Yapılan analiz sonuçlarına göre, kişilik özellikleri ve alt boyutları ile kariyer değerleri ve alt boyutları arasında pozitif yönlü anlamlı bir etkinin olduğu bulgusuna ulaşılmıştır. Kariyer değerleri üzerinde kişilik özelliklerinin anlamlı bir etkisi olduğu bulgusuna ulaşılmıştır. Ayrıca araştırmaya katılan öğrencilerin, en yüksek düzeyde gelişime açıklık, en düşük düzeyde duygusal denge kişilik özelliklerine sahip oldukları ve en yüksek düzeyde saf meydan okuma, en düşük düzeyde girişimcilik kariyer değerlerine sahip oldukları sonucuna varılmıştır. Çalışma kapsamında son olarak, araştırma bulgularından hareketle çeşitli teorik ve yönetsel çıkarımlar aktarılmış, araştırmanın kısıtlarına değinilmiş ve konu özelinde çalışma yapacak araştırmacılara yönelik önerilerde bulunulmuştur.

Staphylococcus aureus is a highly versatile pathogen in a large number of domestic animals, including avian species. To gain deeper insight into the epidemiology and diversity of S. aureus associated with articular disease in domestic turkeys, isolates were collected from infected foot joints of turkeys in Brittany (France). A total of 34 isolates were recovered and characterized by means of antimicrobial resistance, staphylococcal protein A typing, macrorestriction pulsed-field gel electrophoresis and micro-array analysis. Thirty isolates were identified as clonal complex (CC) 398 and methicillin-susceptible S. aureus (MSSA), one was identified as a methicillin-resistant S. aureus (MRSA) CC398 isolate, and the remaining were also MSSA and belonged to CC5, CC101, and CC121. Eleven different antimicrobial resistance patterns were detected, with most isolates resistant to penicillin and tetracycline. Based on all typing methods used, the 34 isolates could be divided into 22 different strains. Results on selected isolates, genotyped using microarrays, indicated a high homogeneity among pathogenic MSSA isolates from turkeys. Moreover, all isolates, except the unique MRSA isolate, carried specific φAvβ prophage avian-niche-specific genes, demonstrating the versatility of S. aureus to adapt to the specific ecological poultry niche.

Marek's disease virus (MDV) isolated from poultry flocks in three states of India was monitored for the virus occurrence in the field. The MDV genome was isolated from feather follicles, spleen, and liver of the chicken (173 samples). Twenty two samples were positive for MDV genome in PCR and belonged to the serotype 1. The sequencing of MEQ gene of 11 samples revealed that nucleotide sequences of the isolate Ind-KA-01-06 was similar to the very virulent MDV, strain RB-1B. In situ hybridization studies also confirmed a presence of MDV serotype 1 in the infected liver tissues. Furthermore, the ability of the virus to induce apoptosis detected by flow cytometry showed that the virulent MDV induced apoptosis more efficiently than Turkey herpesvirus (HVT) vaccine virus. The present study showed the presence of virulent/very virulent MDV strains in the Indian poultry flocks.

An initial census of layer farms in Khartoum State, Sudan, was carried out in late 2007 and early 2008 and found that there were 252 layer farms with a total population of 2 221 800 birds. This paper reports the findings of the census. Based on this information, a structured questionnaire survey of 92 farms was then conducted in the state in April 2008 to collect data on antibiotic usage, demographic data and public health awareness. Ninety-eight per cent of participating farms comprised open-sided houses. It was found that 49% of the farms surveyed were on antibiotic treatment when the survey was conducted, whilst 59% of the farms had used antibiotics within the last 3 months. The study found that farmers and producers had a lack of knowledge about antimicrobial residues, their withdrawal periods and the risk posed by the consumption of these residues. The study also concluded that traditional farming systems in Sudan relied heavily on antimicrobial medication to control disease an...

Salmonellosis is one of the most common bacterial foodborne diseases of public health concern in industrialized countries. Poultry products are considered an important source of Salmonella-related foodborne disease in humans. This study was undertaken to evaluate the relationship between various management factors including feed withdrawal and transportation time with Salmonella contamination in crops, ceca, and carcasses of broiler chickens at slaughter in Alberta. Using a two-stage sampling procedure, 30 matched crop and cecal samples before evisceration and an additional 30 neck skin samples after final wash of broiler chickens were collected at slaughter. A questionnaire was administered at the time of sampling to collect information on flock management risk factors. Cecal contents were individually screened with Salmonella-specific real-time PCR to detect positive flocks, and all cecal, crop, and neck skin samples from positive flocks were processed further for Salmonella isola...

Poultry farming not only provides high nutritious food but also creates employment opportunity for rural masses. Documented evidences elaborates that helminth parasitism is most deciduous problem of chickens especially in developing world. Ascaridia (A.) galli, a nematode of small intestine, has been considered as the most common and important parasite of chicken. The present study was carried out to investigate prevalence and severity of A. galli in White Leghorn layers (housing type: battery cage and deep litter, 50 each) and Fayoumi-Rhode Island Red crossbred (male and female: 50 each) flock rearing at Government Poultry Farm, Dina, Punjab, Pakistan. Two hundred faecal samples were examined by using standard parasitological and McMaster egg counting technique. The overall prevalence was 24.5% at farm, 13% in White leghorn layer (battery cage=2%, deep litter=24%) and 36% in Fayoumi-Rhode Island Red (male=34%, female=38%). It was also observed that White leghorn layer rearing in de...

Fungal infections in poultry, though less prevalent than bacterial and viral diseases, are increasingly recognized as significant respiratory threats, with aspergillosis being the most common mycosis. The disease, primarily caused by Aspergillus fumigatus and A. flavus, arises from inhalation of spores found in contaminated litter, feed, hatcheries, or ventilation systems. Stress, poor ventilation, overcrowding, nutritional deficiencies, and immunosuppressive conditions increase susceptibility, particularly in young chicks, turkeys, and ducklings. The infection manifests in acute or chronic forms, depending on spore load and host immunity, and may affect the respiratory and nervous systems. Seasonality, environmental humidity, and housing practices strongly influence outbreaks, with higher prevalence during warm, damp conditions. While moldy substrates such as feed, feathers, and litter act as reservoirs, hatchery contamination remains a key source of infection. Clinical outcomes vary with immune status, coinfections, and environmental stressors, often leading to high mortality. Interestingly, certain Aspergillus species, such as A. niger and A. awamori, exhibit probiotic effects when used as dietary supplements, highlighting a paradoxical role of the genus in poultry health. Effective management requires strict biosecurity, proper nutrition, and improved housing practices.

Vaccination against avian influenza (AI) is currently applied worldwide with inactivated vaccines. Since November 2012 , a novel recombinant rHVT-AIH 5 (Herpesvirus of turkeys as vector) vaccine has been commercialized and applied to day-old chicks (DOC) in some industrial hatcheries in Egypt (Kilany , 2014 ; Kilany , 2012). The objectives of this study were to assess the cost-effectiveness of AI DOC vaccination in hatcheries and the feasibility of implementing AI DOC vaccination in the different production sectors in Egypt. A model of the Egyptian poultry production network was combined with a model on flock immunity to simulate the distribution profile of AI immunity according to different vaccination scenarios (including DOC vaccination or not). The model estimated the levels of vaccine coverage for each node of the network and vaccination scenario and positive sero-conversion levels and the duration of sero-protection. The model predicted that targeting DOC AI vaccination in ind...

The immunity profile against H5N1 highly pathogenic avian influenza (HPAI) in the commercial poultry value chain network in Egypt was modeled with the use of different vaccination scenarios. The model estimated the vaccination coverage, the protective seroconversion level, and the duration of immunity for each node of the network and vaccination scenario. Partial budget analysis was used to compare the benefit-cost of the different vaccination scenarios. The model predicted that targeting day-old chick avian influenza (AI) vaccination in industrial and large hatcheries would increase immunity levels in the overall poultry population in Egypt and especially in small commercial poultry farms (from ,30% to .60%). This strategy was shown to be more efficient than the current strategy of using inactivated vaccines. Improving HPAI control in the commercial poultry sector in Egypt would have a positive impact to improve disease control.

The effectiveness of recombinant turkey herpesvirus avian influenza (A/swan/Hungary/4999/2006(H5N1)) clade 2.2 virus (rHVT-H5) vaccine was evaluated in two layer chicken breeds (White Bovans [WB] and Brown Shaver [BS]). One dose of rHVT-H5 vaccine was administered at day 1 and birds were monitored serologically (haemagglutination inhibition test) and virologically for 19 weeks. Maternally-derived antibody and post-vaccination H5 antibody titres were measured using the Chinese (A/Goose/Guangdong/1/96(H5N1)) HA and the Egyptian (A/chicken/Egypt/128s/2012(H5N1)) HA as antigens. The challenge was conducted at 19 weeks of age and on six experimental groups: Groups I (WB) and II (BS), both vaccinated and challenged; Groups III (WB) and IV (BS), both vaccinated but not challenged; Groups V and VI, unvaccinated specific pathogen free chickens, serving respectively as positive and negative controls. The challenge virus was the clade 2.2.1 highly pathogenic avian influenza H5N1 A/chicken/Egyp...

Broilers commonly suffer from necrotic enteritis (NE). Other gastrointestinal infectious diseases affect poultry, including nematode infections which are considered a re-emerging disease in barn and free-range systems. The aim of this study was to characterize the immune response of broilers after artificial infection with NE and contrast these with responses to the nematode Ascaridia galli and determine whether immune parameters measured during the course of infection can be used to distinguish infected from uninfected birds. A total of 96 one-day-old male Ross 308 broiler chickens were used in this study. At 10 days of age, broilers were randomly assigned to one of the following treatment groups: control birds (n = 32), A. galli infected birds (n = 32), or NE infected birds (n = 32) and inoculated with the appropriate infective agents. The immune response of birds was monitored through evaluation of haematology parameters, acute phase protein production, and intraepithelial intest...

This study on the prevalence of poultry diseases in Bangladesh's Gopalganj district provides an overview of the challenges faced by local farmers. The research identifies Gumboro disease (35%) and Newcastle disease (15%) as the most common illnesses, contributing to high mortality rates, particularly in young birds. The findings also reveal that poor biosecurity and a lack of vaccination on some farms contribute to the spread of disease. The paper suggests that improving farm management, enhancing biosecurity, and promoting vaccination programs are crucial for the sustainability of the region's poultry industry.

Avian hepevirus infections were detected in chickens suffering from big liver and spleen disease or hepatitis–splenomegaly syndrome in Australia, the USA and Europe. Available data indicate their genetic relationship to mammalian hepatitis E virus (HEV). In the present study, the near-complete genomic sequences of an Australian and a European isolate of avian hepatitis E virus (avian HEV) are reported for the first time. Furthermore, the phylogenetic relationship to other avian HEVs is determined. Sequence analyses of these isolates identified major genetic differences among avian HEVs. Most of them are located within the open reading frame (ORF)1 region, although only a few lie within conserved motifs of predicted domains. Non-silent mutations in the ORF2 region suggest the presence of potentially different epitopes among avian HEV isolates. Finally, phylogenetic analysis confirmed the distant relationship to mammalian HEV and additionally suggested that the avian HEVs can be separ...

Avian hepatitis E virus (HEV) isolates could be separated into at least three genotypes. In this study, the development of the first duplex TaqMan real-time reverse transcription-PCR (RT-PCR) assay for detection and quantification of avian HEV is presented. Primers and probes binding within relatively conserved open reading frame 3 (ORF3) were designed. Tenfold dilution series of in vitro -transcribed avian HEV RNA were used as the standard for quantification. A 712-bp region of the green fluorescent protein gene was transcribed in vitro and used as a heterologous internal control for both RNA isolation and real-time RT-PCR. The duplex real-time RT-PCR for avian HEV had an efficiency of 1.04, a regression squared value of 0.996, and a sensitivity of approximately 3.6 × 10 3 copies per reaction mixture when in vitro -transcribed RNA was used as the template. The presence of in vitro -transcribed heterologous internal control RNA did not affect amplification of avian HEV RNA compared ...

We describe the identification and characterization of the H9N2 influenza subtype reported in Egyptian broiler and broiler breeder farms for the first time. Circulation of this subtype in a highly pathogenic H5N1 influenza virus endemic population provides an opportunity for genetic reassortment and emergence of novel viruses.

Background and Aim: The quality of day-old chicks is a cornerstone to successful poultry production. Chicks with a poor quality start slowly in the field and may have high feed intake, poor growth rate, and poor feed conversion ratio. The current study aimed to assess chick quality challenges encountered from day-old chicks hatched in most commercial hatcheries in Ghana. Materials and Methods: A total of 300 day-old chicks each were obtained from commercial hatcheries in Ghana and Europe. The chicks were labeled as locally hatched broiler day-old chicks (LBDOC) and foreign hatched broiler day-old chicks (FBDOC), respectively. Chicks were reared and monitored from day old to 21 days post-hatch. Sample of chicks (n=25) from each hatchery was euthanized weekly at 1, 7, 14, and 21 days and blood samples collected for analysis. The parameters measured included physical, hematological, immunological, histological, and bacteriological characteristics. All data were analyzed by SAS Proc GLM...

In this study we sequenced and analysed the fimH and fimA genes of 24 avian pathogenic Escherichia coli (APEC) isolates, in order to investigate their possible conserved nature. Additional parameters (serotype, presence of aerobactin receptor, expression of F1 pili and virulence for chickens) were investigated to look for correlations with the obtained sequences. The sequence analysis demonstrated that FimH is highly conserved among all investigated APEC strains (> 99% homology), whereas the major subunit FimA is less conserved, presenting 6 variable regions distributed along the protein. A hydrophilicity analysis suggested several variable domains of FimA to be potential epitopes. We were able to classify the investigated strains into three main groups, on the basis of the amino-acid sequences of the variable regions. This grouping was consistent throughout all variable regions and was independent of serotype, leading to an improved classification of the F1 pili. No correlation was found between the fimH and fimA sequences and the following parameters: avian species, organ of isolation, serotype, presence of aerobactin receptor and virulence for chickens. This study elucidated the molecular structure and the degree of conservation of FimH and FimA among various avian pathogenic E. coli strains.

Data were collected on the prevalence of salmonella at different stages during the life cycle of 18 broiler flocks on different farms as well as during slaughter in different poultry slaughterhouses. For the isolation of salmonella, the highest sensitivity (93.9%) was obtained by enrichment in the semi-solid agar Diasalm. The ‘overshoe method’ utilizing several pairs of overshoes provided the highest sensitivity for determining the salmonella status of the broilers during rearing. A clear decrease of the relative importance of the first production stages was demonstrated for the salmonella contamination of the end product, whereas horizontal transmission of salmonella to broilers during rearing and to broiler carcasses in the slaughterhouse was shown to be the main determinative factor. Ten of the 18 flocks received a salmonella positive status with the highest shedding occurring during the first 2 weeks of rearing. The shedding of the animals was significantly negatively influenced...

In Europe, outbreaks of acute mortality in layer flocks due to colisepticaemia have frequently been observed since the mid-1990s. The aims of this study were to describe the disease, to identify the serotypes of the avian pathogenic Escherichia coli (APEC) present in these outbreaks, and to detect the presence of F11 fimbriae and flagella in the isolates. For this purpose, 20 flocks with APEC-associated increased mortality and 20 control flocks matched for age were examined. Weekly mortality rates in the colibacillosis-affected flocks reached 1.71%, versus 0.30% in the control flocks. The maximum cumulative mortality over an entire colibacillosis outbreak reached 9.19%. The disease was often flock and hen house associated, with recurrent outbreaks within one round and in successive rounds in the same house. Disease was usually acute without clinical symptoms. Peritonitis with yolk material deposited in the peritoneal cavity and polyserositis were the main lesions at necropsy. O78 strains were isolated in 15 of the 20 colibacillosis flocks, and in only one of the control flocks. The majority of strains from the control flocks could not be serotyped by the 28 O-antisera used. In general, F11 fimbriae and flagella were present in the majority of the strains. F11 fimbriae were significantly more often found in O78 isolates than in the other serotypes, and are thus more often present in isolates from colibacillosis flocks. Strains positive for F11, and for F11 and flagella, were more frequently present in heart and liver of the colibacillosis-affected flocks.

Colibacillosis appears to be of increasing significance in layer flocks, but there have been no studies of the risk factors associated with outbreaks. This study aimed to investigate the possible associations between risk factors of non-infectious nature and outbreaks of mortality due to colibacillosis in flocks of caged layer hens. Information on management, biosecurity measures and housing conditions was collected in 20 flocks suffering from the disease and in 20 clinically healthy control flocks. The data were processed using multiple logistic regression. The statistical analysis demonstrated that an increase in the distance to the nearest poultry farm by 1 km was associated with a six-fold decreased risk of an outbreak of colibacillosis (odds ratio/0.16). Furthermore, a 1 l increase in cage volume per hen was associated with a 33% decrease in the risk of an outbreak (odds ratio/0.75). It was concluded that the distance between poultry farms and the hen density in the cages are important risk factors for outbreaks of colibacillosis in flocks of layer hens.

This study aimed to examine the significance of interactions between Escherichia coli and various respiratory pathogens during outbreaks of colibacillosis-associated mortality in layer hen flocks under field conditions. For this purpose, a case Á /control study involving 20 control flocks with baseline mortality and 20 flocks with increased mortality due to E. coli septicaemia and polyserositis, was conducted. In each colibacillosis flock, blood samples were taken from 20 hens at the onset of clinical disease and three times thereafter at 2-week intervals. Control flocks of comparable ages were sampled in the same way. Pooled sera, taken at the first and last sampling, were examined for antibody titres against infectious bronchitis virus (IBV) and Newcastle disease virus (NDV), and the individual sera from all four samplings were examined for the presence and/or titres of antibodies against avian pneumovirus (APV), Mycoplasma gallisepticum, Mycoplasma synoviae and Ornithobacterium rhinotracheale. Titre increases were seen for IBV D274 (one control flock) and O. rhinotracheale (one control and one colibacillosis flock). An increase in per cent reactors was seen for APV (one control flock), and for M. synoviae (one control and two colibacillosis flocks). The study failed to detect any consistent interactions between E. coli and the aforementioned pathogens.These results indicate that, at least as observed in this study, outbreaks of increased mortality resulting from colibacillosis are not necessarily associated with IBV, NDV, APV, M. gallisepticum, M. synoviae or O. rhinotracheale infections.

The changing epidemiology of methicillin-resistant(MRSA) from a hospital-associated pathogen to an organism commonly found in the community and in livestock reflects an organism well-equipped to survive in diverse environments and adjust to different environmental conditions including antimicrobial use. We investigated the molecular epidemiology ofand MRSA in poultry in Ebonyi State, Nigeria. Samples were collected from 1800 birds on 9 different farms within the state. Positive isolates were tested for antibiotic susceptibility and molecular typing. Prevalence in birds was 13.7% (247/1800). MRSA prevalence in poultry was 0.8%. The prevalence of MRSA in broilers and layers was 1.2% and 0.4%, respectively. All tested isolates were susceptible to vancomycin. Molecular analysis of the isolates revealed 3types: t002, t084, and a noveltype, t11469. The noveltype t11469 belonged to sequence type ST5. The detection of t002 in chicken suggests the presence of livestock-associated MRSA in pou...

Fowl cholera (FC) caused by Pasteurella multocida is among the serious infectious diseases of poultry. Currently, formalin inactivated FC (FI-FC) vaccine is widely used in Ethiopia. However, reports of the disease complaint remain higher despite the use of the vaccine. The aim of this study was to develop and evaluate gamma-irradiated mucosal FC vaccines that can be used nationally. In a vaccination-challenge experiment, the performance of gamma-irradiated P. multocida (at 1 kGy) formulated with Montanide gel/01 PR adjuvant was evaluated at different dose rates (0.5 and 0.3 ml) and routes (intranasal, intraocular, and oral), in comparison with FI-FC vaccine in chicken. Chickens received three doses of the candidate vaccine at 3-week intervals. Sera, and trachea and crop lavage were collected to assess the antibody levels using indirect and sandwich ELISAs, respectively. Challenge exposure was conducted by inoculation at 3.5×10 9 CFU/ ml of P. multocida biotype A intranasally 2 weeks after the last immunization. Repeated measures ANOVA test and Kaplan Meier curve analysis were used to examine for statistical significance of antibody titers and survival analysis, respectively. Sera IgG and secretory IgA titers were significantly raised after second immunization (p=0.0001). Chicken survival analysis showed that intranasal and intraocular administration of the candidate vaccine at the dose of 0.3 ml resulted in 100% protection as compared to intramuscular injection of FI-FC vaccine, which conferred 85% protection (p=0.002). In conclusion, the results of this study showed that gamma-irradiated FC mucosal vaccine is safe and protective, indicating its potential use for immunization of chicken against FC.

Fowl cholera (FC) caused by Pasteurella multocida is among the serious infectious diseases of poultry. Currently, formalin inactivated FC (FI-FC) vaccine is widely used in Ethiopia. However, reports of the disease complaint remain higher despite the use of the vaccine. The aim of this study was to develop and evaluate gamma-irradiated mucosal FC vaccines that can be used nationally. In a vaccination-challenge experiment, the performance of gamma-irradiated P. multocida (at 1 kGy) formulated with Montanide gel/01 PR adjuvant was evaluated at different dose rates (0.5 and 0.3 ml) and routes (intranasal, intraocular, and oral), in comparison with FI-FC vaccine in chicken. Chickens received three doses of the candidate vaccine at 3-week intervals. Sera, and trachea and crop lavage were collected to assess the antibody levels using indirect and sandwich ELISAs, respectively. Challenge exposure was conducted by inoculation at 3.5×10 9 CFU/ ml of P. multocida biotype A intranasally 2 weeks after the last immunization. Repeated measures ANOVA test and Kaplan Meier curve analysis were used to examine for statistical significance of antibody titers and survival analysis, respectively. Sera IgG and secretory IgA titers were significantly raised after second immunization (p=0.0001). Chicken survival analysis showed that intranasal and intraocular administration of the candidate vaccine at the dose of 0.3 ml resulted in 100% protection as compared to intramuscular injection of FI-FC vaccine, which conferred 85% protection (p=0.002). In conclusion, the results of this study showed that gamma-irradiated FC mucosal vaccine is safe and protective, indicating its potential use for immunization of chicken against FC.

Avian infectious bronchitis virus is a highly contagious disease occurring in respiratory, urogenital, and reproductive tissues of chicken causing considerable losses due to death, egg drop, and reduced production. is preliminary study was conducted to investigate the prevalence of antibodies against infectious bronchitis virus (IBV) and to assess the potential risk factors in chickens of northwest Ethiopia. A cross-sectional study was conducted from November 2020 to June 2021. A total of 768 serum samples from three zones were collected. To investigate the presence of antibodies against IBV, the indirect ELISA serological test was applied. Positivity for anti-IBV antibodies was observed in 23.96% (95% CI: 20.98-27.14) of the samples. e mixed-effect logistic regression analysis of potential risk factors showed that IBV prevalence was significantly higher in young chickens than adults (p < 0.001) and higher in intensive farm type than in extensive type (p < 0.001). Based on the production purposes of the chickens, the odds of seropositivity for IB was significantly higher in layers than in broilers (p < 0.001) and dual purposes (p < 0.001). is study revealed higher seroprevalence in farms which had the "all-in-all-out" rearing method than in farms with different batches in one house with a significant difference (p < 0.001), higher seroprevalence in the poor ventilated type than in good ones (p < 0.001), and higher seroprevalence in the houses that did not remove used litter at all than houses of completely disposed and partially disposed litter (p � 0.002). Moreover, disinfection of houses had significant effect on the occurrence of IB. Having personal protective equipment was significantly affecting the occurrence of IB, being higher in the farms that have no wearing clothes and shoe than in those having wearing clothes and shoe (p � 0.002). In conclusion, the seroprevalence finding in the present study indicated that the organism is circulating among the population of chickens and high enough to cause significant economic losses erefore, poultry houses should be cleaned, disinfected, and well ventilated and farm attendants should have separate farm shoe and clothes. Further studies on the virus isolation and molecular characterization of the target gene are needed in the study area.

The effects of crude thymus extract on the immune response and protection against challenge with virulent infectious bursal disease virus (IBDV) were studied in one-day-old chick. Oral administration of thymus extract (1 ml/kg) markedly and significantly increased the total protein, albumin, globulin, Tri-iodothyronine (T3), Thyroxine (T4) and the body weight gain in one-day-old chick. In addition, it increased the total lymphocytic count over four weeks after administration. Although vaccination also increased total protein, globulin, T4 and the total lymphocytic count but it significantly decreased the body weight gain of the chick and administration of thymus extract, before, during or after vaccination markedly improved the vaccination effectiveness with significant elevation of the globulin level and body weight gain of the chick. It also prevented the decrease in the relative weights of bursa, spleen and thyroid gland which commonly prevailed during vaccination. Chicken administered thymus extract and vaccinated with infectious bursal disease (IBD) vaccine showed 100 % protection against challenge with IBDV. Meanwhile the vaccinated non-thymus treated group exhibited 80% protection against IBDV challenge. These results indicate a potentiating effect of thymus extract on the immune system in baby chick. These findings are supported by ELISA results that showed a marked increase in antibody titers in thymus treated groups. Additionally, microscopical examination of the bursa and the existent lymphoid hyperplasia in thymus treated groups but not vaccinated group support our findings.

We have shown the results of routine microbiological testing and susceptibility of Staphylococcus aureus isolates that were isolated from cows with inflammation of mammary gland during a five year period. Totally, 2719 strains identified as Staphylococcus aureus were routinely tested to twelve antimicrobial agents by the agar-disc diffusion technique. The strains were isolated from 45000 samples of udder secretion on Columbia agar plates containing 5% of defibrinated ovine blood (0.01 ml on a quarter of culture medium). They were identified on the basis of colony morphology, catalase and coagulase tests, a tube coagulase test and the strains from 2002 were identified by the API ID 32 Staph system. Of strains isolated in 2002, 70.77% were penicillin-susceptible, higher than any other year, after that 39.

We have shown the results of routine microbiological testing and susceptibility of Staphylococcus aureus isolates that were isolated from cows with inflammation of mammary gland during a five year period. Totally, 2719 strains identified as Staphylococcus aureus were routinely tested to twelve antimicrobial agents by the agar-disc diffusion technique. The strains were isolated from 45000 samples of udder secretion on Columbia agar plates containing 5% of defibrinated ovine blood (0.01 ml on a quarter of culture medium). They were identified on the basis of colony morphology, catalase and coagulase tests, a tube coagulase test and the strains from 2002 were identified by the API ID 32 Staph system. Of strains isolated in 2002, 70.77% were penicillin-susceptible, higher than any other year, after that 39.

Radio-guided localization (RGL) for identifying occult breast lesions has been widely accepted as an alternative technique to other localization methods, including those using wire-guidance. An appropriate phantom model would be an invaluable tool for practitioners interested in learning the technique of RGL prior to clinical application. The aim of this study was to devise an inexpensive and reproducible training phantom model for RGL. We developed a simple RGL phantom model imitating an occult breast lesion from inexpensive supplies including a pimento olive, a green pea and a turkey breast. The phantom was constructed for a total cost of less than $20 and prepared in approximately 10 minutes. After the first model's construction, we constructed approximately 25 additional models and demonstrated that the model design was easily reproducible. The RGL phantom is a time-and cost-effective model that accurately simulates the RGL technique for nonpalpable breast lesions. Future studies are warranted to further validate this model as an effective teaching tool.

For integrated pest management (IPM) programs to be maximally effective, monitoring of the growth and decline of the pest populations is essential. Here, we present the validation results of a new automated monitoring device for the poultry red mite (Dermanyssus gallinae), a serious pest in laying hen facilities world-wide. This monitoring device (called an &quot;automated mite counter&quot;) was validated in experimental laying hen cages with live birds and a growing population of D. gallinae. This validation study resulted in 17 data points of &#39;number of mites counted&#39; by the automated mite counter and the &#39;number of mites present&#39; in the experimental laying hen cages. The study demonstrated that the automated mite counter was able to track the D. gallinae population effectively. A wider evaluation showed that this automated mite counter can become a useful tool in IPM of D. gallinae in laying hen facilities.

This submitted work was designed in order to evaluate the prophylactive efficacy of the synthetic copper (I)nicotinate complex against nephrotoxicity by aflatoxin B1 (AFB1) with regard to the highly accepted antioxidant agent butylated hydroxytoluene (BHT). Aflatoxin B1 fraction was obtained by growing Aspergillus flavus in potato dextrose agar (PDB) liquid medium. Healthy young males albino rats (n=45) were exposed to AFB1 day after day for five weeks (20 µg/kg body weight). One third of them was co-treated with BHT (0.05 g/kg body weight) and the second third by the copper complex (400 µg/kg body weight) while the third was considered as only intoxicated control group. Such intoxication resulted into the histopathological (light and electron transmission) characteristic features of nephrotoxicity. The sever degenerative changes swelling of the cells even rapture of the membrane and cellular organelles in the tubular lumen as well as fibrocytic reaction and congestion of the vasculature in addition to glomerular reaction manifested by atrophy of both vesiral (bodocyte) and parital shirnked cells. The co-treated BHT group did not eliminate all such features of degenerative characters in intoxicated tissue kidney while the co-treated copper complex group mostly appeared normal. The enzyme level of phase II of body detoxificating GST was significantly increased than that improved by BHT. Conclusively, the food additive probable use of the copper nicotinate complex could be a promising agent against nephrotoxicosis.

In the spring of 2012 an outbreak of H7N3 highly pathogenic (HP) avian influenza virus (AIV) occurred in poultry in Mexico. Vaccination was implemented as a control measure, along with increased biosecurity and surveillance. At that time there was no commercially available H7 AIV vaccine in North America; therefore, a recent H7N3 wild bird isolate of low pathogenicity from Mexico (A/cinnamon teal/Mexico/2817/2006 H7N3) was selected and utilized as the vaccine seed strain. In these studies, the potency and efficacy of this vaccine strain was evaluated in chickens against challenge with the 2012 Jalisco H7N3 HPAIV. Although vaccine doses of 256 and 102 hemagglutinating units (HAU) per bird decreased morbidity and mortality significantly compared to sham vaccinates, a dose of 512 HAU per bird was required to prevent mortality and morbidity completely. Additionally, the efficacy of 11 other H7 AIV vaccines and an antigenic map of hemagglutination inhibition assay data with all the vacci...

One of the approved methods for controlling viral diseases endemic in Iraq, which cause huge economic losses, is the use of vaccines to protect birds against these diseases. This study aimed to evaluate the immune response to two vaccination programs commonly used in Iraq. To achieve this goal, one-day-old Rose 308 broiler chicks were brought in and divided into three groups. The first group was vaccinated in the hatchery at one day old with an intensive vaccination program against avian influenza, Newcastle disease, infectious bronchitis, and infectious bursitis. The chicks in the second group were vaccinated with the same vaccination program in the first group, but on the fifth day of the chicks' life, with the addition of two doses of Newcastle disease vaccine at the age of 15 and 25. As for the chicks in the third group, they were left without vaccination as a control group. The humoral immunity of the chicks was measured at the age of 10, 20, and 30 days by ELISA, and and the histopathological changes of lymphoid organs was also measured. The results showed no significant differences between the two vaccinated groups in terms of humoral immunity and histopathological changes of lymphoid organs, and there was a clear significant difference with the control group. we conclude that both vaccination programs induce a good humoral immune response. the vaccination programs (time of vaccination, type of vaccine, routs of administration) applied in poultry houses lead to histopathogical changes in lymphoid organ may be used in estimated immune response in chickens. Further future studies need on vaccination programs designs until reach to suitable program can protecting chickens against infectious diseases.

We genetically analyzed field isolates of the Newcastle disease (ND) virus isolated in Japan from 1930 to 2001. The coding region of the fusion protein was amplified by reverse transcriptase PCR and directly sequenced. Phylogenetic analysis revealed the presence of viruses belonging to six of the eight known genotypes. It can be concluded from this study that ND outbreaks in Japan have been of multiple etiologies.

The objective of this study was to find the relation between the pathogenicity of (E. coli) O78 chicken isolate alone or mixed with Riemerella anatipestifer infection by conventional methods and modern techniques. The results of this study revealed that the pathogenicity of all groups of Riemerella anatipestifer (RA) was 100% while it was 90% among the ducks inoculated with E. coli and was 100% in the injected with both strains of Riemerella anatipestifer and E. coli together and 0% in the control negative group. RA and E. coli strains were correctly identified using the VITEK 2 compact system with 99% and 94% probability, respectively. The results of polymerase chain reaction confirmed the identification results using specific primers either for E. coli O78 or Riemerella anatipestifer giving products 720bp and 665bp, respectively. Histopathological examination revealed that liver showed congestion in blood vessels and hepatic cell necrosis in the group inoculated within Riemerella anatipestifer, While liver showed only congested blood vessels in E. coli inoculated group. On the other hand, Liver showed severe vacuolar degeneration with focal amyloid infiltration in E. coli and Riemerella inoculated group.

Mycoplasma synoviae infections result in significant economic losses in the chicken and turkey industries. A commercially available live temperature-sensitive (ts ' ) vaccine strain MS-H has been found to be effective in controlling M. synoviae infections in commercial layer and broiler breeder farms in various countries, including Australia. Detection and differentiation of MS-H from field strains (ts ( ) and from ts ( MS-H reisolates in vaccinated flocks is vital in routine flock status monitoring. At present microtitration is the only available technique to determine the ts phenotype of M. synoviae. This technique is time consuming and not amenable to automation. In the present study, a quantitative real-time polymerase chain reaction (Q-PCR) was combined with simultaneous culturing of M. synoviae at two different temperatures (338C and 39.58C) to determine the ts phenotype of 22 Australian M. synoviae strains/isolates. The M. synoviae type strain WVU-1853 was also included for comparison. A ratio of the copy numbers of the variable lipoprotein haemagglutinin (vlhA) gene at the two temperatures was calculated and a cut-off value was determined and used to delineate the ts phenotype. In all M. synoviae strains/isolates tested in this study, the ts phenotype determined using Q-PCR was in agreement with that determined using conventional microtitration. Combination of Q-PCR with differential growth at two different temperatures is a rapid, reliable and accurate technique that could be used as an effective tool in laboratories actively involved in ts phenotyping of M. synoviae strains/isolates.

The bacterial pathogen Mycoplasma synoviae can cause subclinical respiratory disease, synovitis, airsacculitis and reproductive tract disease in poultry and is a major cause of economic loss worldwide. The M. synoviae strain MS-H was developed by chemical mutagenesis of an Australian isolate and has been used as a live attenuated vaccine in many countries over the past two decades. As a result it may now be the most prevalent strain of M. synoviae globally. Differentiation of the MS-H vaccine from local field strains is important for epidemiological investigations and is often required for registration of the vaccine. The complete genomic sequence of the MS-H strain was determined using a combination of Illumina and Nanopore methods and compared to WVU-1853, the M. synoviae type strain isolated in the USA 30 years before the parent strain of MS-H, and MS53, a more recent isolate from Brazil. The vaccine strain genome had a slightly larger number of pseudogenes than the two other str...

Background: Antibiotics are preferred drugs for controlling coccidiosis. However, prolonged use of ionophores will result in Eimeria resistance to these drugs. Objectives: The present work was conducted to evaluate the possible substitution of prebiotic (nutri yeast [NY]) for antibiotics in mild-challenged broilers with Eimeria. Methods: A total of 420 1-d-old male Ross 308 chicks were used in a completely randomized design with 7 treatments and 5 replicates. Experimental treatments included: 1) Negative control (NC) (without prebiotic and challenge); 2) Positive control (PC) (without prebiotic and challenged with sporulated oocysts of Eimeria [SO]); 3) 0.2% NY in starter, 0.1% in grower, 0.05 % in finisher, challenged with SO; 4) 0.2 % NY in starter, 0.1 % in grower, 0.05 % NY in finisher, without challenge; 5) 0.2% NY in the whole rearing period of chicks challenged with SO; 6) 0.2% NY in the whole rearing period of chicks without challenge; and 7) Salinomycin (0.05 % of diet). At 7 d of age, treatments 2, 3 and 5 were challenged with a 20-fold dose of Eimeria vaccine via oral gavage. Antibody levels against sheep red blood cell (SRBC) were measured at 31 and 41 days of age. On days 28 and 42, two birds per replicate were slaughtered to collect ileal digesta for microbial analysis. Samples were collected for blood metabolite parameters, carcass traits and visceral organ weight, intestinal morphology, and interleukin 6 (IL-6) gene expression on day 42. Results: The results showed that NY supplementation increased the concentration of serum total protein (3.10 vs 2.57 g/dL) and decreased serum triglycerides (50.6 vs 57.3 mg/dL) and cholesterol (108.6 vs 133.9 mg/dL) levels compared to NC group (P<0.05). Serum antibody titers against Newcastle were higher in prebiotic treatments compared to control groups, and for the secondary immune response against SRBC broilers fed NY diet had the highest levels of total Ig (8.4 vs 6.4) and IgG (5.6 vs 4.2) compared to the control group (P<0.05). The inclusion of NY improved intestinal pH and the relative weights of immune organs, breast muscle, and small intestine compared to the NC treatment (P<0.05). Villus height (806.6

Riemerella anatipestifer, the causative agent of septicemia anserum exsudativa (also called new duckling disease), belongs to the family Flavobacteriaceae of gram-negative bacteria. We determined the DNA sequences of the rrs genes encoding the 16S rRNAs of four R. anatipestifer strains by directly sequencing PCR-amplified rrs genes. A sequence similarity analysis confirmed the phylogenetic position of R. anatipestifer in the family Flavobacteriaceae in rRNA superfamily V and allowed fine mapping of R. anatipestifer on a separate rRNA branch comprising the most closely related species, Bergeyella zoohelcum, as well as Chryseobacterium balustinum, Chryseobacterium indologenes, and Chryseobacterium gleum. The sequences of the rrs genes of the four R. anatipestifer strains varied between 0.5 and 1.0%, but all of the strains occupied the same position on the phylogenetic tree. In general, differences in rrs genes were observed among R. anatipestifer strains, even within a given serotype,...

Aims: A comparison of the prevalence of Salmonella in chicken carcasses with and without visible faecal contamination during commercial slaughter practice was made. The relationship between Enterobacteriaceae, coliform and Escherichia coli counts and Salmonella status was also evaluated to establish the likelihood of using these groups as ‘index’ organisms to predict the presence of pathogen. Methods and Results: Samples were removed immediately after evisceration, after the inside–outside shower and after chilling from the processing line for microbiological analysis. Of the carcasses visibly uncontaminated with faeces after the evisceration step 20% harboured salmonellas and 20·8% of the visibly contaminated carcasses were positive for the pathogen. When E. coli, coliforms and Enterobacteriaceae were used as predictor variables the error rates ranged from 33·3 to 60% for both sample types. Conclusions: There was no indication that any of the groups of organisms analysed could pred...

The effectiveness of recombinant turkey herpesvirus avian influenza (A/swan/Hungary/4999/2006(H5N1)) clade 2.2 virus (rHVT-H5) vaccine was evaluated in two layer chicken breeds (White Bovans [WB] and Brown Shaver [BS]). One dose of rHVT-H5 vaccine was administered at day 1 and birds were monitored serologically (haemagglutination inhibition test) and virologically for 19 weeks. Maternally-derived antibody and post-vaccination H5 antibody titres were measured using the Chinese (A/Goose/Guangdong/1/96(H5N1)) HA and the Egyptian (A/chicken/Egypt/128s/2012(H5N1)) HA as antigens. The challenge was conducted at 19 weeks of age and on six experimental groups: Groups I (WB) and II (BS), both vaccinated and challenged; Groups III (WB) and IV (BS), both vaccinated but not challenged; Groups V and VI, unvaccinated specific pathogen free chickens, serving respectively as positive and negative controls. The challenge virus was the clade 2.2.1 highly pathogenic avian influenza H5N1 A/chicken/Egyp...

Avian hepevirus infections were detected in chickens suffering from big liver and spleen disease or hepatitis–splenomegaly syndrome in Australia, the USA and Europe. Available data indicate their genetic relationship to mammalian hepatitis E virus (HEV). In the present study, the near-complete genomic sequences of an Australian and a European isolate of avian hepatitis E virus (avian HEV) are reported for the first time. Furthermore, the phylogenetic relationship to other avian HEVs is determined. Sequence analyses of these isolates identified major genetic differences among avian HEVs. Most of them are located within the open reading frame (ORF)1 region, although only a few lie within conserved motifs of predicted domains. Non-silent mutations in the ORF2 region suggest the presence of potentially different epitopes among avian HEV isolates. Finally, phylogenetic analysis confirmed the distant relationship to mammalian HEV and additionally suggested that the avian HEVs can be separ...