Serological study and risk factor analysis on Peste des Petits Ruminants in sheep in Bangladesh.

A cross-sectional study was conducted to determine the seroprevalence of the Peste des Petits Ruminant (PPR) virus (PPRV) in sheep populations and to determine the potential epidemiological risk factors associated with this infection. Between October 2014 and March 2017, 2420 sheep serum samples were collected from ten selected PPR outbreak-prone districts in Bangladesh. The collected sera were analysed by competitive enzyme-linked immunosorbent assay (cELISA) test to detect antibodies against PPR. A previously designed disease report form was used to gather data on important epidemiological risk factors, and a risk analysis was performed to ascertain their association with PPRV infection. By cELISA, 44.3 % (95 % confidence interval:42.4-46.4 %) of sheep sera were positive for PPRV antibodies against PPR. In univariate analysis, the Bagerhat district had significantly higher seropositivity (54.1 %, 156/288) than other districts. Moreover, significantly higher (p < 0.05) seropositivity was found in the Jamuna River Basin (49.1 %, 217/442) compared to other ecological zones, in crossbreeds (60 %; 600/1000) related to native sheep, in males (69.8 %, 289/414) associated with females, in imported sheep (74.3 %, 223/300) compared to other sources, and in winter (57.2 %, 527/920) than in other seasons. In the multivariate logistic regression model, six possible risk factors were identified: study location, ecological zone, breed, sex, source, and season. The high seroprevalence of PPRV is significantly associated with several risk factors, suggesting that PPR is epizootic throughout the country.

Molecular characterization of duck plague virus from selected Haor areas of Bangladesh.

Background: Duck viral enteritis, commonly known as duck plague (DP), is an acute and contagious fatal disease in ducks, geese, and swans caused by the DP virus (DPV). It poses a serious threat to the growth of duck farming in the Haor (wetland) areas of Bangladesh. Aim: This study aimed to detect the circulating DPV by molecular characterization, followed by phylogenetic analysis, targeting the UL30 gene in infected ducks from five Haor districts in Bangladesh and to observe the variation in the genome sequence between the field virus and vaccine strain of DPV. Methods: A total of 150 samples (liver, 50; intestine, 50; and oropharyngeal tissue, 50) were collected from DP-suspected sick/dead ducks from 50 affected farms in Kishoreganj, Netrokona, B. Baria, Habiganj, and Sunamganj districts in Bangladesh. For the identification of DPV in collected samples, polymerase chain reaction (PCR) was utilized. Nucleotide sequences of the amplified UL30 gene were compared with those of other DPV strains available in GenBank. Results: Of the 150 samples, 90 (60%) were found to be positive for DPV, as confirmed by PCR. Organ-wise prevalence was higher in the liver (72%), followed by the intestine (64%) and oropharyngeal tissue (44%). Regarding areas, the highest and lowest prevalence in the liver and intestine was observed in Habiganj and B. Baria, respectively, whereas the highest and lowest prevalence in the oropharyngeal tissue was observed in B. Baria and Habiganj, respectively. Two isolates, BAU/KA/DPV(B1)/2014 from Kishoreganj and BAU/KA/DPV(B4)/2014 from Sunamganj were sequenced, and phylogenetic analysis revealed that these isolates are evolutionarily closely related to Chinese isolates of DPV. Additionally, the isolates of DPV BAU/KA/DPV(B1)/2014 and BAU/KA/DPV(B4)/2014 showed the highest (98%) similarity to each other. The nucleotide sequence of the isolate BAU/KA/DPV(B1)/2014 exhibited higher nucleotide variability (246 nucleotides) than that of the vaccine strain (accession no. EU082088), which may affect protein function and additional drug sensitivity. Conclusion: Based on the findings of the molecular study, it can be assumed that the Bangladeshi isolates and all Chinese isolates of DPV may have a common ancestry.

An assessment on potential risk pathways for the incursion of highly pathogenic avian influenza virus in backyard poultry farm in Bangladesh.

BACKGROUND AND AIM: Highly pathogenic avian influenza (HPAI) is a deadly virus of zoonotic potential. The study mainly aims to determine the risk pathways (RPs) for the probable incursion of HPAI virus (HPAIV) in backyard poultry in Bangladesh. MATERIALS AND METHODS: The study involves expert elicitation technique. The concept map determines the possible RPs. The map consists of 16 concepts, each with nodes from which probabilities of an event originates. These probabilities are described by qualitative descriptors ranging from negligible to high. Risk assessment has been performed using the subjective risk assessment tool. RESULTS: The tool demonstrates positive correlation among groups of experts in the level of agreement by scoring RP; however, the level of agreement varies from 71% to 93% among group of experts. The median risk score of viral incursion through the "Exposure of backyard poultry with farm poultry in the trading market" was 11 and ranked as top, followed by "Contaminated live bird market environment" and "Sharing common scavenging space with migratory birds" (median risk score, 10.5; rank, 2), and "Scavenging of infected slaughtered poultry remnants by backyard poultry" (median risk score, 5.3; rank, 3) when no control options were applied along with the RPs. After applying or considering control option along with contaminated live bird market environment, the median risk score was reduced to 5.0. Applying a specific control option along with each RP reduced estimated median risk scores for HPAIV incursions. CONCLUSION: This study provides an insight into the incursion risks of HPAIV through various RPs in backyard poultry in Bangladesh.

Knowledge, attitude, and practice of a local community towards the prevention and control of rabies in Gaibandha, Bangladesh.

OBJECTIVES: Knowledge, attitude, and practice (KAP) of rabies in the community are essential for developing post-exposure behavioral treatment and for understanding current prevention and control policy on rabies. This was a cross-sectional study in Gaibandha Sadar, a northern district of Bangladesh, investigating the level of KAP about rabies. MATERIALS AND METHODS: A total of 368 interviewed respondents, of whom 280 (76.09%) were male, and 88 (23.91%) were female. A structured questionnaire was used for the data collection from respondents on socio-demographic information and KAP regarding rabies. The data analyzed with STATA-IC-11.0 and the association of independent variables with rabies KAP scores were calculated using Pearson's Chi-square. RESULTS: Most respondents had adequate KAP levels and positive thoughts on rabies prevention. The KAP scores were strongly associated with education and employment status (p < 0.05). Most respondents said that stray dogs are a headache in the area and believed that control of the dog population in Gaibandha is essential. CONCLUSION: These outcomes also revealed that there is an information gap about rabies that might improve by developing an education program for awareness.

Seroprevalence and risk factors of avian reovirus in backyard chickens in different areas of Mymensingh district in Bangladesh.

OBJECTIVE: The present study estimated the seroprevalence of avian reovirus (ARV) infections in backyard chickens of the Mymensingh district in Bangladesh. MATERIALS AND METHODS: Considering several risk factors, a total of 460 serum samples were collected from backyard chickens from eight Upazilas of the Mymensingh district in Bangladesh. Blood samples were taken from the wing vein using 3-ml sterile syringes and kept at room temperature for clotting in a slanting position and then transported to the laboratory maintaining the cool chain. Subsequently, the prepared sera were harvested and stored at -20°C until used. Finally, an indirect enzyme-linked immunosorbent assay (ELISA) was performed to detect ARVspecific antibodies using a commercial ARV antibody detection ELISA test kit. RESULTS: The results revealed high prevalence rates of ARV antibodies, with a total seroprevalence of 69.78% (321/460). Area-wise, 74.55% (82/110) seroprevalence was recorded as the highest in Mymensingh Sadar, whereas 64% (32/50) was the lowest in Gauripur Upazila. With regard to sex, female chickens showed a significantly higher (p < 0.05) seroprevalence as 90.33% (271/300) compared to male chickens 31.25% (50/160). With regard to age groups, the seroprevalence of ARV infection was 59.33% (89/150) within 2-8 weeks, 82% (205/250) within 9-16 weeks, and 45% (27/60) within 17-20 weeks, respectively. Based on hygienic conditions, the highest seroprevalence of ARV was noted in backyard chickens housed in poor conditions 80% (120/150) than good conditions 50% (40/80). Backyard chickens reared in free-ranging conditions exhibited a significantly higher seroprevalence 73.33% (220/300) of ARV antibodies compared to rearing in separate houses 63.12% (101/160). The seroprevalence of ARV was higher in crossbreeds 71.67% (43/60), brought from market 76% (38/50), and unhealthy 78.57% (55/70) backyard chickens than non-descriptive indigenous 69.5% (278/400), home-reared 69.02% (283/410), and healthy chickens 68.21% (266/390). CONCLUSION: The high prevalence of ARV antibodies revealed in the current study indicates an extensive exposure of ARV to backyard chickens in Bangladesh that may be transmitted naturally to other chickens, ultimately leading to ominous economic effects on the poultry sector.

Detection of antibiotic-resistant bacteria and their resistance genes from houseflies.

BACKGROUND AND AIM: Houseflies (Musca domestica) are synanthropic insects which serve as biological or mechanical vectors for spreading multidrug-resistant bacteria responsible for many infectious diseases. This study aimed to detect antibiotic-resistant bacteria from houseflies, and to examine their resistance genes. MATERIALS AND METHODS: A total of 140 houseflies were captured using sterile nylon net from seven places of Mymensingh city, Bangladesh. Immediately after collection, flies were transferred to a sterile zipper bag and brought to microbiology laboratory within 1 h. Three bacterial species were isolated from houseflies, based on cultural and molecular tests. After that, the isolates were subjected to antimicrobial susceptibility testing against commonly used antibiotics, by the disk diffusion method. Finally, the detection of antibiotic resistance genes tetA, tetB, mcr-3, mecA, and mecC was performed by a polymerase chain reaction. RESULTS: The most common isolates were Staphylococcus aureus (78.6%), Salmonella spp., (66.4%), and Escherichia coli (51.4%). These species of bacteria were recovered from 78.3% of isolates from the Mymensingh Medical College Hospital areas. Most of the isolates of the three bacterial species were resistant to erythromycin, tetracycline, penicillin and amoxicillin and were sensitive to ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, and azithromycin. Five antibiotic resistance genes of three bacteria were detected: tetA, tetB, mcr-3, and mecA were found in 37%, 20%, 20%, and 14% isolates, respectively, and no isolates were positive for mecC gene. CONCLUSION: S. aureus, Salmonella spp., and E. coli with genetically-mediated multiple antibiotic resistance are carried in houseflies in the Mymensingh region. Flies may, therefore, represent an important means of transmission of these antibiotic-resistant bacteria, with consequent risks to human and animal health.

Microbial risk assessment of ready-to-eat mixed vegetable salads from different restaurants of Bangladesh Agricultural University campus.

OBJECTIVE: The study was aimed to analyze the microbiological quality of mixed vegetable salads and to understand the risk related with its consumption from different restaurants around Bangladesh Agricultural University campus in Mymensingh. MATERIALS AND METHODS: Sixty (60) samples of mixed vegetable salads were taken from twelve (12) different restaurants in five different time points from each restaurant. In parallel, restaurant workers were asked for handling practices while the consumers were interviewed about their salad consumption pattern and whether they had experienced any health-related problems. Microbial risk assessment of Staphylococcus spp., Salmonella spp., and Escherichia coli was estimated by Monte Carlo simulation (10,000 iterations), an exponential model. RESULTS: Aerobic plate count was ranged from 7.73 ± 0.61 to 9.04 ± 0.26 log cfu/gm, Staphylococcus spp. from 4.64 ± 0.61 to 6.42 ± 0.53 log cfu/gm, Salmonella spp. from 4.75 ± 0.08 to 5.27 ± 0.53 log cfu/gm, and E. coli from 4.98 ± 0.20 to 6.66 ± 0.80 log cfu/gm. From the survey, it was found that total consumers had 18% chances where the male had 13% and the female had 30% chances of being infected with salads. Again frequent, average, and occasional consumers had 31%, 13%, and 0% chances, respectively, of being infected with those salads. From the Monte Carlo simulation, the calculated mean annual risks of Staphylococcus spp., Salmonella spp., and E. coli infection for the three exposure scenarios were found to be about 100%. CONCLUSION: The study actually revealed the potential microbial contamination in mixed vegetable salads which may impact on food safety and human health. So, the findings suggest that following hygienic measures during processing and handling the microbiological quality of mixed vegetables salads can be improved.

Microbial load in bio-slurry from different biogas plants in Bangladesh.

OBJECTIVE: The study was aimed to isolate, identify, and characterize common indicator bacteria, including Escherichia coli, Salmonella spp., and Staphylococcus spp. in manure and bio-slurry samples of different livestock farms and biogas plants of Bangladesh. MATERIALS AND METHODS: A total of 114 samples of manure and bio-slurry were collected from different livestock farms and biogas plants in Bangladesh. The total viable count (TVC), E. coli, Salmonella spp., and Staphylococcus spp. counts were determined by the spread plate technique method. Isolation and identification were performed by colony characteristics, staining, biochemical tests, and, finally, by using PCR. Antibiotic susceptibility test of the isolated bacteria was tested against commonly used antibiotics by using the disk diffusion method. RESULTS: The mean TVC, E. coli, Salmonella spp., and Staphylococcus spp. counts were ranged from 8.19-10.75, 5.2-6.96, 5.81-6.87, 5.68-7.68 in manure samples and 7.26-8.65, 3.82-5.2, 4-5.54, 3.14-5.9 log cfu/gm in bio-slurry, respectively. In anaerobic digester after 30 days digestion, the presence of E. coli, Salmonella spp., and Staphylococcus spp. varied from 0-5.11, 0-4.84, and 0-5.59 log cfu/gm at 25°C, 27°C, 29°C, and 45°C temperature. Above-mentioned bacteria were absent in bio-slurry collected from anaerobic digester after 60 days digestion at environmental temperature. Bacterial counts were reduced significantly in both household slurry pits and experimental anaerobic digester. Antibiotic susceptibility results revealed that multidrug-resistant indicator bacteria were present in the bio-slurry samples. CONCLUSION: Our findings conclude that the microbial load after treatment of animal manure via anaerobic digestion (Biogas plant) was grossly reduced and the reduction of bacterial pathogen depends on the duration and temperature of digestion.

Antibiotic-resistant Escherichia coli and Salmonella spp. associated with dairy cattle and farm environment having public health significance.

AIM: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. MATERIALS AND METHODS: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR.The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. RESULTS: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). CONCLUSION: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.

Serological detection of avian reovirus in different poultry flocks of Gazipur and Mymensingh districts of Bangladesh.

BACKGROUND AND AIM: Avian reovirus (ARV) is a constraint to poultry industry in Bangladesh as a cause of several diseases in chickens, especially in broiler. However, the actual status of the viral infection is not known because the large-scale study is not conducted in this country. Therefore, this study aimed to check the presence and distribution of ARV-specific antibody in respect to area, types of chickens (broiler breeder, broiler, and layer), vaccination status, and age of chickens in Gazipur and Mymensingh districts of Bangladesh. MATERIALS AND METHODS: A total of 276 chickens' blood samples were collected from two well-organized broiler breeder stock, seven broiler farms, and five layer farms located at two districts, namely Gazipur and Mymensingh of Bangladesh. Blood samples were collected from wing vein of the apparently healthy chickens using 3 ml of syringe and serum was harvested by keeping the syringe at room temperature in slanting position. The sera were transferred to the laboratory by maintaining the cool chain and further processing was performed by indirect enzyme-linked immunosorbent assay using ARV antibody test kit. RESULTS: The results of serological test revealed that an average of 39.5% seropositive against ARV was recorded in chickens of Gazipur and Mymensingh districts. Among these, chickens of Gazipur district had the highest seropositivity of 50.5% than Mymensingh (30.7%). With respect to vaccination status, the seropositivity of vaccinated chickens in both areas was 100% and non-vaccinated chickens was 50.5% in Gazipur and 30.7% in Mymensingh district, respectively. However, regarding age groups, the seropositivity was higher in the age of 4-6 weeks (64.5%). CONCLUSION: The present serological findings showed a higher prevalence of ARV-specific antibodies in broiler birds. It indicates that the poultry industries of Bangladesh are contaminated with ARV which may naturally be transmitted to chickens either vertically or horizontally.

Characterization of Staphylococcus aureus isolated from chicken and quail eggshell.

OBJECTIVES: This study was conducted to assess the prevalence and characterization of Staphylococcus aureus from chicken and quail eggshells and to study the antibiogram of the isolates. MATERIALS AND METHODS: A total of 300 eggs (220 chicken eggs and 80 quail eggs) were collected from different retail shops and farms in Mymensingh district. Swabs taken from the egg surfaces were cultured on Mannitol Salt Agar for the isolation of S. aureus. Polymerase chain reaction was conducted for confirmatory identification of the bacterial species targeting nuc gene, followed by confirmation of methicillin-resistant S. aureus by targeting the mecA gene. Antibiotic sensitivity test of the isolated bacteria was done against commonly used antibiotics by the disk diffusion method. RESULTS: The prevalence of Staphylococcus spp. and S. aureus in the chicken eggshell surface was 20.45% and 10.45%, respectively. Similarly, the prevalence of Staphylococcus spp. and S. aureus in quail eggshell surface was 16.25% and 5%, respectively. Overall, 27 isolates were identified as S. aureus, of which 23 were from the chicken eggshell surface and four from quail eggshell surface. Among the seven isolates tested, overall four (57.14%) were positive for the nuc gene. On the other hand, the mecA gene could be detected in three (50%) S. aureus out of six oxacillin resistant isolates. The antibiogram study indicated that most of the isolates were resistant to the antibiotics under ß-lactam group. CONCLUSION: The present study concludes that chicken and quail egg surface harbor multidrug-resistant bacteria which may cause public health hazards, if these antibiotic-resistant bacteria are transferred to a human.