Chickens In Bangladesh Research Articles

Characterization of predominant genotype (QX) of avian infectious bronchitis virus isolated from layer chickens in Bangladesh

Avian infectious bronchitis (AIB) is a highly transmissible infection that affects the poultry industry globally. This study aims to isolate and characterize emerging strains of infectious bronchitis virus (IBV) from field samples of layer chickens in Bangladesh. A total of 108 samples (trachea, lung, and kidney) were taken from dead and sick layer chickens from 18 farms in 4 areas detecting outbreaks in Bangladesh. The samples were processed and inoculated in embryonated chicken eggs (ECEs) and finally screened by the trypsin-induced hemagglutination (THA) test. Using various techniques such as hemagglutination inhibition (HI), agar gel immuno-diffusion (AGID), virus neutralization test (VNT), reverse transcription-polymerase chain reaction (RT-PCR), and nucleotide sequencing, we were able to identify and confirm the isolated IBV viruses. The study also determined the hemagglutination (HA) pattern of isolated virus using avian and mammalian red blood cells. The pathogenicity of the isolated IBV was determined using embryonated chicken eggs and day-old chicks. The study found that 8 samples were positive for IBV using ECEs, and 4 were positive by the THA test. These isolates were confirmed using HI, AGID, and VN tests. S1 gene-based RT-PCR confirmed all four isolates as IBV, with the recent isolates belonging to the genotype-QX and being similar to IBV isolates from Thailand, Saudi Arabia, and India. The HA pattern of the recent isolates showed that the isolated IBV was virulent. The pathogenicity test also revealed that the four isolates were highly pathogenic. The study indicated that the prevalent genotype (QX) of the IBV strain is present in the layer chicken population of Bangladesh.

Characterization of infectious laryngotracheitis virus isolated from commercial layer chickens in Bangladesh during the year 2021-2022.

Infectious laryngotracheitis virus (ILTV) is responsible for causing infectious laryngotracheitis (ILT), which is a rapidly spreading and extremely transmissible disease in chickens. The current research aims to isolate and characterize ILTV from layer chickens in Bangladesh. A total of 345 samples (trachea, larynx, and lungs) were collected from ILT-suspected dead and sick layer chickens of 32 ILT-suspected farms in three different outbreak districts (Gazipur, Tangail, and Mymensingh) of Bangladesh during the outbreak year 2021-2022. Rapid detection kits examined the samples for avian influenza virus (AIV) and Newcastle disease virus (NDV). ILTV-specific primers were used to screen 72 NDV- and AIV-negative samples by polymerase chain reaction (PCR). Using chorioallantoic membrane (CAM), the study isolated the ILT virus from 9 to 10-day-old seronegative embryonated chicken eggs (ECEs) using selected PCR-positive samples. The virus was confirmed using nucleotide sequencing, agar gel immunodiffusion test (AGIDT), viral neutralization test (VNT), and pathogenicity evaluations using mortality index for chicken embryos (MICEs) and intra-tracheal pathogenicity index (ITPI). The results indicated that among the PCR-positive 10 samples, only two (Alim_ILT_1001 and Alim_ILT_1,000) were found positive using ECEs. There were two field isolates of ILTVs, as shown by the amplicon size of the ICP4 gene-based PCR. A phylogenetic study of the ICP4 gene revealed that the recent isolates have a close similarity with the ILTV isolates of Turkey, Bangladesh, and Australia. AGIDT revealed strong precipitation lines due to ILTV-specific antibodies reacting with field viruses, while VNT neutralized both isolates with conventional ILTV antibodies. The pathogenicity testing indicated that Alim_ILT_1001 had MICE and ITPI values of 0.77 and 0.63, whereas Alim_ILT_1,000 had 0.71 and 0.57. Both the ILTV isolates have similarities with the isolates of Turkey, Bangladesh, and Australia, and they are highly virulent for chickens.

Characterization of the dominant strain (G-VII) of Newcastle disease viruses isolated from commercial chickens in Bangladesh during recent outbreaks.

Newcastle disease virus genotype VII (NDV-GVII), an extremely infectious pathogen, has been causing severe economic consequences for the chicken industry. The current study aimed to isolate and characterize NDV-GVII from commercial chickens in Bangladesh during a recent outbreak. From clinically suspected chickens from 70 commercial poultry farms, a total of 420 samples (trachea, lungs, and brain tissue) were collected. The samples were cultivated in 9-10 day-old seronegative embryonated chicken eggs (ECEs) after evaluating them using the rapid Newcastle disease virus (NDV) antigen detection kit. The hemagglutination (HA) inhibition test, agar gel immune diffusion (AGID) test, molecular detection by reverse transcription-polymerase chain reaction (RT-PCR), and phylogenetic studies using gene sequences of fusion (F) protein. The HA pattern of isolated NDV was determined using different avian and mammalian red blood cells (RBCs). The pathogenicity of the isolated virus was evaluated using mean death time (MDT), intravenous pathogenicity index (IVPI), and intracerebral pathogenicity index (ICPI). The study found 87 NDV samples positive using the rapid NDV Ag detection kit and then 60 positives for virus isolation in ECEs. All 60 isolates were positive for NDV by HI, AGID, and RT-PCR. Phylogenetic tree analysis indicated that recent NDV isolates belong to genotype VII and exhibit a similarity of 99.7%-98.5% with isolates from Bangladesh, Iran, and India. The new isolates, identified as velogenic strains of NDV, possess an F protein cleavage site with 112-R-T-K-R-F-117 amino acid motifs. The isolated NDV showed diversified HA activity while using RBCs from birds and mammals. The results of ICPI, IVPI, and MDT indicated that the recent NDV isolates were very virulent. This study concluded that NDV-GVII is prevalent in commercial poultry farms in Bangladesh.

Circulation of the reassorted very virulent genotype of infectious bursal disease virus isolated from vaccinated broiler chickens in Bangladesh

Objective: The methodology employed in this research was designed to identify and characterize the infectious bursal disease virus (IBDV) at the molecular level, originating from recent outbreaks in Bangladesh. Materials and Methods: The IBDV outbreak farm was investigated, and bursa of Fabricius (BF) specimens were acquired from infected chickens. Initially, viruses in the processed samples were detected in chicken embryo fibroblast (CEF) cells, and the RT-PCR method was used to confirm IBDV. The positive samples were injected through chorioallantoic membrane route into the embryo of a 10-day-old specific pathogen-free (SPF) egg for virus isolation and pathogenicity testing. Finally, we sequenced the VP2 gene to identify phylogenetic relationships and detect mutations. Results: From the 77 collected samples, 42.85% (33/77) were found positive for cytopathic effects in CEF cells, and IBDV was detected in 31.16% (24/77) of the samples by RT-PCR. IBDV was isolated in SPF chicken embryos. In the pathogenicity test, infectious bursal disease was evident in seronegative chickens with visible signs of disease. Sequence analysis shows that the broiler-isolated viruses clustered with genotype A3B2 and backyard chickens with genotype A1B1. The presence of amino acid motifs for virulence markers was revealed in the partially sequenced VP2 gene with a mutation at S254G in four IBDV isolates from broilers. However, amino acids for virulence markers were absent in two isolates from backyard chickens, which shows sequence homology with IBDV classic strains. Conclusion: In this study, we identified and characterized circulating reassorted IBDV from vaccinated broilers, which may be one of the major causes of vaccination failure in broilers.

Ascaridia galli, a common nematode in semiscavenging indigenous chickens in Bangladesh: epidemiology, genetic diversity, pathobiology, ex vivo culture, and anthelmintic efficacy

Ascaridia galli is the most common nematode in chickens. Ascaridia galli is highly prevalent in chickens reared in scavenging or semi-scavenging systems. Here, we studied the epidemiology, pathology, genetic diversity, ex vivo culture protocol and anthelmintic sensitivity of A. galli prevalent in indigenous chickens in Bangladesh. Through morphological study and molecular analyses, the isolated worms were confirmed as A. galli. Of the chickens examined, 45.6% (178 out of 390) were found infected. The male and young chickens were significantly (p<0.05) more prone to A. galli infection. Prevalence of the infection was significantly (p<0.05) lower in the summer season. In heavy infections, A. galli blocked the small intestine. Marked inflammation, increased mucus production and petechial hemorrhages were evident in the small intestine, particularly in the duodenum. Also, there were desquamation and adhesion of the mucosal villi; degeneration, necrosis of the epithelial cells and goblet cell hyperplasia. The mucosal layer was infiltrated mainly with eosinophils and heterophils. We developed a hen egg white-based long-term ex vivo culture protocol which supported the survival and reproduction of A. galli for more than a week. Levamisole (LEV) and ivermectin (IVM) efficiently killed A. galli. However, albendazole (ABZ), mebendazole (MBZ) and piperazine (PPZ) did not kill the worms even at higher concentrations. Taken together, our results suggest that A. galli is highly prevalent in semi-scavenging chickens in Bangladesh. Ascaridia galli can be easily maintained ex vivo in egg white supplemented M199 medium. LEV and IVM, but not ABZ, MBZ and PPZ, can be used for treating and controlling A. galli infections in chickens.

Multidrug Resistance and Molecular Characterization of Klebsiella spp. Isolated from the Cloacal Samples of Broiler Chickens in Bangladesh

Klebsiella spp. poses a significant zoonotic threat, capable of direct and indirect transmission from poultry farms to humans, resulting in severe conditions such as pneumonia, bloodstream infection, enteric fever, meningitis and urinary tract infections. The escalating use of antibiotics in the poultry industry is contributing to the rise of multidrug-resistant (MDR) microorganisms. Thus, a study was undertaken to comprehend the multidrug resistance and virulence gene profile of Klebsiella spp. isolated from poultry cloacal samples sourced from local markets of North Dhaka, Bangladesh. Following aseptic collection, the samples were transported to the laboratory for pure culture isolation. Employing standard microbiological methods such as mucoid colony characteristic, Gram-negative rod-shaped bacteria, biochemical tests and lactose fermentation in selective media, the isolated colonies were presumptively identified. Subsequently, an antibiotic susceptibility test, utilizing the disk diffusion assay, was conducted to assess drug sensitivity in these isolates. A PCR assay was performed to determine the presence or absence of KPC gene of Klebsiella. Among the isolates, ten colonies were identified as Klebsiella spp. based on the colony characteristics, Gram staining, biochemical tests and growth on selective media. Notably, eight isolates (excluding 2 and 4) were incapable of producing indole from tryptophan, indicating the presence of two different types of species. All isolates exhibited resistance to at least three antibiotics, namely ceftazidime, ampicillin and cefoxitin. Isolate 2 and 5 were demonstrated additional resistance to azithromycin, while isolate 9 and 10 exhibited further resistance to streptomycin and doxycycline. Molecular analysis indicated that 40% of these isolates harbor KPC virulent gene (880bp), with the most multidrug resistant isolate 9 and 10 possessing this gene. This study is pivotal for assessing the prevalence of virulent and MDR Klebsiella spp. in chicken cloacal samples, providing insights into shedding and transmission risk on soil and water environment, as well as to humans.

Draft genome sequence of Staphylococcus gallinarum MTR_B001 strain isolated from breast muscle of a chicken in Bangladesh.

We announce the genome sequence of the Staphylococcus gallinarum MTR_B001 strain isolated from the breast muscle of a chicken in 2022 in Bangladesh. This assembled genome had an estimated length of 2,889,393 bp (with 50× genome coverage), 15 contigs, 36 predicted antibiotic resistance genes, and 27 predicted virulence factor genes.

Village Chicken Production and Management Practices in Barishal, Bangladesh

Village chickens are an important source of income and protein for village people in Bangladesh, like in many other developing countries. Since the productivity of the chickens is low, their production might be improved through better management practices. In this regard, village chicken production and management practices were investigated to know the present status and its limitations. We selected 150 farmers from 3 Upazilas (Babuganj, Bakerganj, and Barishal Sadar) in the Barishal district and collected information in a structured questionnaire and through observations. The results show that the village chicken production system was extensive with a low amount of supplemental feed. 87.34% of farmers provided supplement feed to their chickens once or twice a day, while the rest of the farmers did not provide any supplement feed. All of the farmers had a poultry shelter to keep their chickens at night, but we found the shelters to be almost dirty. They were reluctant to clean the shelter, as only 14.67% of farmers cleaned the shelters once a month, while the others did not. Chickens of multiple age groups were kept in the same shelter without maintaining biosecurity. As a preventive measure, 58.67% of farmers vaccinated their chickens, primarily for Newcastle disease. They did not maintain a vaccination schedule. Only 15.33% and 4% of farmers practiced deworming and external parasite control, respectively. For the mating of chickens, the farmers did not select males and females. Though the village chickens seem to be reared and consumed by chicken owners, only 32.87% of chicken products were consumed by chicken owners, and the rest were sold at village markets. Under these circumstances, it can be stated that the low productivity of village chickens could be due to lack of adequate nutrition, unhealthy housing, disease outbreaks, unplanned mating, and improper management practices. The practices of dietary supplements, providing healthy housing, ensuring a vaccination schedule, mating with good partners, and good management practices could improve the productivity of village chickens in Bangladesh.

First Evidence of Fowl Adenovirus Induced Inclusion Body Hepatitis in Chicken in Bangladesh.

The livestock sector contributes 1.90% to the GDP in Bangladesh during 2021-22. Poultry is one of the important subsectors struggling with diseases. Fowl adenoviruses (FAdVs) cause numerous diseases resulting in economic losses to the poultry industry worldwide. Several FAdV serotypes cause inclusion body hepatitis in chicken. Although FAdV infection was suspected, there was no confirmatory report from Bangladesh. The study was conducted to investigate the FAdV infection and antibodies in chicken. A total of 50 samples, each composed of liver and spleen, were collected from different chickens of Gazipur, Dinajpur, and Panchagarh district. Each location belongs to A, B, and C poultry zones of Bangladesh, respectively. Viruses were detected by real-time PCR and conventional PCR. Blood samples (n = 303) were collected at the beginning and after the recovery from infection and tested by indirect ELISA. Sequencing of PCR products was done for serotyping and phylogenetic analysis. Clinical signs were observed including anorexia, drowsiness, ruffled feathers, reduced body weight, lack of uniformity, and high mortality (15-25%). Enlarged friable liver with yellow to tan color mottled with the focal soft area, fluid in pericardial sac, swollen and hemorrhagic kidneys, enlarged congested spleen and pancreas, etc. were found on postmortem examination. FAdVs were detected in 90% of the flocks except commercial layer flock from Dinajpur. Three serotypes, namely, 8b (70%), 11 (10%), and 5 (10%) were detected. Anti-FAdV antibody was detected in 80% flocks at the beginning of infection and in 90% of the flocks after recovery from infection. The antibody titer increases significantly (p < 0.05) after recovery from infection. Phylogenetic analysis revealed that the Bangladeshi FAdVs have close identity with viruses from Asia, Europe, and South and North America. These findings suggested that several introductions of FAdVs were taken place in Bangladesh. To combat the disease, vaccination along with maintenance of biosecurity is essential.

Phenotypical Identification and Toxinotyping of Clostridium perfringens Isolates from Healthy and Enteric Disease-Affected Chickens.

Clostridium perfringens is a ubiquitous spore-forming anaerobic pathogen that is frequently associated with enteric disease in chickens. Moreover, enterotoxin-producing C. perfringens has high zoonotic potential as well as serious public health concerns due to the emanation of food-borne intoxication. The present study was designed to isolate, identify, and toxinotype C. perfringens from both healthy and cases of necrotic or ulcerative enteritis chickens. A total of 110 samples were collected from July 2019 to February 2021. Among the samples, 38 (34.5%, 95% CI: 26.39-43.83) were positive for C. perfringens and were obtained from broiler 21 (33.3%, 95% CI: 22.91-45.67), Sonali 9 (34.6%, 95% CI: 19.31-53.88), and layer 8 (38%, 95% CI: 20.68-59.20). C. perfringens was highly prevalent (35.7%, 95% CI: 25.48-47.44) in enteritis chickens compared with healthy ones. In multiplex PCR toxinotyping, 34 (89.4%) isolates were identified as C. perfringens type A by the presence of the alpha toxin gene (cpa). Moreover, in addition to the cpa gene, 3 (14.3%, 95% CI: 4.14-35.48) broiler and 1 (11.1%, 95% CI: 0.01-45.67) Sonali isolates harbored the enterotoxin gene (cpe) and were classified as type F. However, none of the isolates carried genes encoding beta (cpb), epsilon (etx), iota (iap), or beta-2 (cpb2) toxins. Multivariable logistic regression analysis identified the following variables such as; "previously used litter materials" (OR 21.77, 95% CI 2.22-212.66, p ≤ 0.008); intestinal lesions, "presence of ulceration" (OR 30.01, 95% CI 3.02-297.91, p ≤ 0.004); "ballooned with gas" (OR 24.74, 95% CI 4.34-140.86, p ≤ 0.001) and "use of probiotics" (OR 5.24, 95% CI 0.74-36.75, p ≤ 0.095) act as risk factors for C. perfringens colonization in chicken gut. This is the first study of molecular toxinotyping of C. perfringens from healthy and enteric-diseased chickens in Bangladesh, which might have a potential food-borne zoonotic impact on human health.

The First Report of a Virulent Newcastle Disease Virus of Genotype VII.2 Causing Outbreaks in Chickens in Bangladesh.

Newcastle disease (ND) is endemic in poultry in Bangladesh. We performed genotypic and pathotypic characterization of four ND virus (NDV) isolates from recent outbreaks in broiler chickens in Bangladesh during the period of 2020-2021. Phylogenetic analysis based on the complete fusion protein gene coding sequences classified the viruses into NDV class II genotype VII.2 together with viruses from Indonesia isolated between 2014 and 2021 and a single 2020 Indian isolate. Pathogenicity testing using the intracerebral pathogenicity index in day-old chickens and mean embryo death time in embryonating chicken eggs revealed that the Bangladeshi isolates are velogenic. Inoculation of 35-day-old chickens with two NDV isolates (LT67 and N5) resulted in 100% morbidity by 3 days post inoculation (DPI), and all birds succumbed to infection by 7 DPI. Massive hemorrhages, congestion and necrotic lesions were observed in different visceral organs, which were typical for infection with a velogenic viscerotropic pathotype of NDV. At microscopic examination, tracheitis, severe pneumonia, focal proventriculitis, transmural enteritis, focal myocarditis, severe congestion and necrosis in kidneys, and lymphoid depletion in lymphoid tissues were found. Our study reports the first outbreak of the panzootic genotype VII.2 NDV in poultry in Bangladesh and documents a possible recent re-introduction of this NDV genotype from Southeast or East Asia. This study further provides viral distribution and epidemiological data that can facilitate the effective control of NDV.

Myxovirus resistance (Mx) Gene Diversity in Avian Influenza Virus Infections.

Avian influenza viruses (AIVs) pose threats to animal and human health. Outbreaks from the highly pathogenic avian influenza virus (HPAIV) in indigenous chickens in Bangladesh are infrequent. This could be attributed to the Myxovirus resistance (Mx) gene. To determine the impact of Mx gene diversity on AIV infections in chicken, we assessed the Mx genes, AIVs, and anti-AIV antibodies. DNA from blood cells, serum, and cloacal swab samples was isolated from non-vaccinated indigenous chickens and vaccinated commercial chickens. Possible relationships were assessed using the general linear model (GLM) procedure. Three genotypes of the Mx gene were detected (the resistant AA type, the sensitive GG type, and the heterozygous AG type). The AA genotype (0.48) was more prevalent than the GG (0.19) and the AG (0.33) genotypes. The AA genotype was more prevalent in indigenous than in commercial chickens. A total of 17 hemagglutinating viruses were isolated from the 512 swab samples. AIVs were detected in two samples (2/512; 0.39%) and subtyped as H1N1, whereas Newcastle disease virus (NDV) was detected in the remaining samples. The viral infections did not lead to apparent symptoms. Anti-AIV antibodies were detected in 44.92% of the samples with levels ranging from 27.37% to 67.65% in indigenous chickens and from 26% to 87.5% in commercial chickens. The anti-AIV antibody was detected in 40.16%, 65.98%, and 39.77% of chickens with resistant, sensitive, and heterozygous genotypes, respectively. The genotypes showed significant association (p &lt; 0.001) with the anti-AIV antibodies. The low AIV isolation rates and high antibody prevalence rates could indicate seroconversion resulting from exposure to the virus as it circulates. Results indicate that the resistant genotype of the Mx gene might not offer anti-AIV protection for chickens.

Prevalence and Antimicrobial Resistance Profile of E. coli and Salmonella spp. from Liver and Heart of Chickens

E. coli and Salmonella spp. are responsible for causing colibacillosis and salmonellosis in chickens respectively. This research work was undertaken to study the prevalence of colibacillosis and salmonellosis in commercial chickens of Chattogram, and to know the antibiogram profiles of the isolated bacteria. A well-structured questionnaire was used to know the prevalence of colibacillosis and salmonellosis. Previously collected liver and heart samples through postmortem of a total of 100 dead and sick chickens were used. MacConkey agar, EMB agar, and XLD agar were used to isolate, and identify E. coli and Salmonella spp. Finally, Gram’s staining and different biochemical tests were performed to identify these two bacterial isolates. 14 different commercially available antimicrobial discs like ciprofloxacin, enrofloxacin, streptomycin, colistin sulphate, neomycin, cefoxitin, amoxycillin, tetracycline, gentamicin, norfloxacin, azithromycin, doxycycline, cloxacillin, and erythromycin were used. Data were analyzed with p-value by using Graph Pad Software. 48 samples were recorded as positive for E. coli and 5 for Salmonella spp. The prevalence of E. coli and Salmonella spp. were varied depending on different parameters like age, bird rearing system, farm size, source of water, source of food, medication and vaccination. Form antibiogram study it was revealed that E. coli was highly sensitive to colistin sulphate and ciprofloxacin; intermediate to gentamicin followed by cefoxitin and resistant to other 10 antimicrobials. In case of Salmonella spp., it was recorded as sensitive to colistin sulphate, and cefoxitin; intermediate to ciprofloxacin, and resistant to other 11 antimicrobials. The findings of this research work would certainly help the poultry farmers to select proper antibiotics against colibacillosis and salmonellosis in chickens of Bangladesh and to overcome the multi-drug resistant problem of the bacteria.

Retinal Ganglion Cell Topography and Spatial Resolving Power of Eye in the Native Chicken of Bangladesh

Retinal Ganglion Cell Topography and Spatial Resolving Power of Eye in the Native Chicken of Bangladesh

Research Note: Genetic analysis, pathology, and vectors of echinostomiasis, a zoonotic helminth infection in chickens in Bangladesh

Echinostomes (Trematoda: Echinostomatidae) are food-borne zoonotic flatworms that affect birds, animals and humans, and has been classified as neglected tropical diseases (NTDs) by the World Health Organization (WHO), which cause severe enteritis in poultry and hamper production. Here, we confirmed the species of echinostomes affecting chickens in Bangladesh along with their genetic analyses, pathology and vectors. We isolated and identified adult worms from chickens, cercariae from fresh water snails and metacerariae (MC) from some wild fishes. We recovered Echinostoma revolutum (10.3%) and Hypoderaeum conoideum (6.0%) from chickens. Zoonotic E. revolutum was confirmed by amplifying nad1 gene and subsequent sequencing. Several mutations were detected in nad1 gene and our isolates belonged to the Euro-Asian clade. We observed thickening of mucosal layer, hyperplasia of goblet cells, infiltration of eosinophils, lymphocytes and must cells in the infected intestine. About 5.3% snails were infected and the highest percentage of infection was found in Lymnaea luteola (12.1%). Echinostome infection in snails was the highest in November (9.6%) and lowest in February (3.1%) in Bangladesh. MC of echinostomes were identified from blue panchax (Aplocheilus panchax) and tank goby (Glossogobius giuris). In conclusion, echinostomiasis is a notable big problem in indigenous chickens in Bangladesh and people, especially, villagers are at risk.

First Isolation and Molecular Characterization of Chicken Astrovirus and Avian Nephritis Virus in Chickens in Bangladesh.

Chicken astrovirus (CAstV) and avian nephritis virus (ANV) are enteric viruses of poultry and have infected a wide range of poultry species worldwide, causing runting-stunting syndrome (RSS), which requires virus screening and results in serious economic damage. No confirmed cases have been reported from Bangladesh. In the present study, CAstV and ANV were monitored in Bangladesh. We monitored samples for CAstV and ANV and compared their genomic sequences to other reference strains. We found 8/31 flocks (25.8%) were positive for CAstV, 6/31 flocks (19.3%) had mixed infection of CAstV and ANV, and 1 flock (3.2%) was positive for ANV. Only ANV and a combination of CAstV and ANV were found in broilers and broiler breeders, but CAstV was found in all types of chickens. We isolated two of each from CAstV and ANV through specific pathogen-free chicken embryonated eggs via the yolk sac route. Phylogenetic analysis based on the ORF1b conserved region of CAstV and ANV suggested that the locally circulating strain was closely related to the strains isolated from India and Brazil. This report is the first molecular characterization of CAstV and ANV in Bangladesh. This study highlights that CAstV and ANV are circulating in Bangladeshi poultry.

Molecular detection and antibiotyping of multi-drug resistant Enterococcus faecium from healthy broiler chickens in Bangladesh.

Background Enterococcus faecium is a ubiquitously distributed member of the intestinal microbiota of both humans and animals. Antibiotic resistant E. faecium are a major public health concern.ObjectivesThis study aimed to detect multi‐drug resistant (MDR) E. faecium and their antibiotic resistance genes from broiler chickens in Bangladesh.MethodsA total of 100 faecal samples of healthy broilers were screened by conventional methods and polymerase chain reaction (PCR) to detect E. faecium and their resistance genes. Disk diffusion test was employed to determine antibiotic profiles.ResultsBy PCR, among 100 samples, 45% [95% confidence interval (CI): 35.62%–54.76%] were positive for E. faecium. Based on antibiogram, all the E. faecium isolates were found resistant to ampicillin, and frequently (93.33%–55.56%) resistant to ceftriaxone, cefotaxime, streptomycin, erythromycin, and imipenem; moderate to lower (26.67%–4.44%) resistance to tetracycline, ciprofloxacin, norfloxacin, chloramphenicol, gentamicin, and vancomycin. Interestingly, 80% (95% CI: 66.18%–89.10%) E. faecium isolates were MDR in nature. In addition, the indices of multiple antibiotic resistance (MAR) ranged from 0.08 to 0.83. By bivariate analysis, high positive significant correlations were observed between resistance profiles of erythromycin and imipenem, ciprofloxacin and norfloxacin, erythromycin and streptomycin, ceftriaxone and cefotaxime, tetracycline and chloramphenicol, and streptomycin and imipenem. Furthermore, the prevalence of resistance genes of E. faecium was 58.33% (tetA), 33.33% (tetB), 35.56% (blaTEM ), 60% (CITM), 13.33% (aadA1), and 12% (SHV).ConclusionsTo the best of our knowledge, this is the first study in Bangladesh to detect MDR and MAR E. faecium and their associated resistance genes. The detection of MDR and MAR E. faecium and their corresponding resistance genes from healthy broilers is of public health concern because of their potential to enter into the food chain.

Detection of extended-spectrum β-lactamase (ESBL) producing Escherichia coli in chickens

Objective: Indiscriminate use of antibiotics in poultry farms increases the chance of antibiotic-resistant and ESBL producing bacteria in Bangladesh. Therefore, the study was undertaken to detect the extended-spectrum β-lactamase (ESBL) producing Escherichia coli (E. coli) in chickens. &#x0D; Materials and methods: A total of 60 cloacal swab samples (20 from commercial layer, 20 from commercial broiler, and 20 from commercial Sonali chickens) were collected from the Rajshahi district of Bangladesh. The E. coli was isolated from these samples and identified based on cultural, staining, and biochemical characteristics. The disk diffusion method was used to assay the antibiotic-resistant/sensitivity patterns of the isolated E. coli. Phenotypic detection of ESBL producing E. coli was also done. &#x0D; Results: The prevalence of E. coli in chickens was 61.67% in the Rajshahi district of Bangladesh, where the prevalence was 60%, 60%, and 65% in a commercial layer, commercial broiler, and commercial Sonali chickens, respectively. The antibiotic sensitivity assay of E. coli isolated from commercial layer chickens showed 100%, 80%, 50%, 40%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ciprofloxacin, and ceftazidime, respectively. E. coli isolated from commercial broiler chickens showed 100%, 100%, 60%, 50%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ceftazidime, and ciprofloxacin, respectively. E. coli isolated from commercial Sonali chickens showed 90%, 70%, 50%, 50%, and 40% resistant to amoxicillin, tetracycline, cefotaxime, ciprofloxacin, and ceftazidime, respectively. In phenotypic detection, the overall prevalence of ESBL producing E. coli was 43.33%, where 40%, 50%, and 40% in the commercial layer, commercial broiler, and commercial Sonali chickens, respectively in the Rajshahi district of Bangladesh. &#x0D; Conclusion: These results indicated that chickens are a potential reservoir for ESBL producing E. coli and their antibiotic resistances are obviously significant. These findings will help us to make a proper guideline for the treatment, prevention, and control of E. coli prevalent in chickens in Bangladesh

Circulation of three genotypes and identification of unique mutations in neutralizing epitopes of infectious bronchitis virus in chickens in Bangladesh.

Infectious bronchitis (IB) is a highly contagious respiratory disease caused by a gammacoronavirus that has been circulating for many years in chickens in Bangladesh, resulting in significant economic losses. The aim of this study was to detect and characterize infectious bronchitis virus (IBV) from clinical outbreaks and surveillance samples. Real-time RT-PCR was used to detect IBV in pooled lung and tracheal tissue samples (n = 78), oropharyngeal swabs (n = 19), and pooled fecal samples (n = 13) from live-bird markets. Both respiratory and nephropathogenic forms of IB were suspected at necropsy (n = 7) from clinical outbreaks. Sequencing of hypervariable regions (HVR1-2 and HVR3) of the region of the spike gene (S) encoding the S1 subunit of five isolates revealed circulation of the Mass-like, QX-like, and 4/91-like genotypes of IBV in Bangladesh. Each genotype was extremely variable, as shown by separate clustering of the viruses in a phylogenetic tree and high nucleotide (nt) sequence divergence (38.8–41.2% and 25.7–37.4% in the HVR1-2 and HVR3 sequence, respectively). The unique mutation G65E was observed in each Mass-like isolate, and Y328S was observed in each 4/91-like Bangladeshi isolate. Three neutralizing epitope sites were predicted within the HVRs that differed significantly among the three genotypes. In addition, one Bangladeshi isolate carried fixed mutations at 294F and 306Y, like other pathogenic QX-like IBVs, which could affect epitopes involved in neutralization, facilitating virus circulation among vaccinated flocks. Therefore, continuous screening and genotype characterization will be necessary to track the epidemiology of IBV and control IB infection in Bangladesh.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00705-021-05227-3.

Morphological Identification and Prevalence of Gastrointestinal Helminths in Backyard Chicken From Selected Areas of Bangladesh

Poultry industry is the promising sub-sector in livestock, which has been expanding day by day. Among the poultry species, backyard chicken is one of the appropriate incomes generating species in rural areas of Bangladesh. Parasitic infections have been considered as one of the major hindrances for backyard chicken rearing. Therefore, the present study aimed to investigate the prevalence of gastrointestinal helminths of backyard chicken in some selected areas of Bangladesh through their detailed morphological identification. A total number of 108 gastrointestinal tracts were examined for helminths from April 2018 to July 2018. The collected helminths were identified according to the keys and description of Yamaguti (1961) and Soulsby (1982). A high rate of helminth infection (100%) was observed in backyard chickens in Bangladesh. One cestode, Raillietina tetragona (67.59%); two nematodes, Ascaridia galli (43.51%) and Heterakis gallinarum (28.70%); and two trematodes, Catatropis verrucosa (21.29%) and Echinostoma revolutum (6.48%) were encountered during the study. Most of the helminths were recovered from small intestine followed by caecum. All five species of helminths were found from Dhaka and Pabna, but surprisingly no trematodes were found from Bandarban. Out of 108 chickens, 29.62% were infected with single species of helminths while the rest 70.38% harbored mixed infections. This work strongly suggests that helminths create serious problems in backyard chicken as they hamper production and therefore, appropriate control strategies are needed to design for better production.&#x0D; Res. Agric., Livest. Fish.8(1): 145-155, April 2021