A serological survey on the prevalence of antibodies against Newcastle disease virus was carried out in broiler and layer chickens in Rajshahi and surrounding districts of Bangladesh. A total of 960 serum samples were collected from broiler (102) and layer (90) farms from January to December 2008. Haemagglutination inhibition (HI) test was performed using Newcastle disease virus antigen to determine antibody titers against Newcastle disease virus. The overall seroprevalence of antibodies against Newcastle disease virus in broiler and layer chickens were 78.04% (510 samples) and 96.67% (450 samples), respectively. Antibody levels against Newcastle disease virus were recorded for different age groups of broiler and layer chickens. Seroprevalence of antibodies against Newcastle disease virus was found significantly (p<0.05) higher in young (broiler 23.88%, layer 11.33%) than in adults (broiler 18.38%, layer 9.22%). Furthermore, these levels were recorded for different seasons of the year, with significantly (p<0.05) higher during summer in comparison to other seasons.

Escherichia coli is known as one of the most important foodborne pathogens in humans, and contaminated chicken meat is an important source of foodborne infection with this bacterium. The occurrence of extended-spectrum &beta;-lactamase (ESBL)-producing E. coli (ESBL-Ec), in particular, in chicken meat is considered a global health problem. This study aimed to determine the magnitude of E. coli, with special emphasis on ESBL-Ec, along with their phenotypic antimicrobial resistance pattern in frozen chicken meat. The study also focused on the determination of ESBL-encoding genes in E. coli. A total of 113 frozen chicken meat samples were purchased from 40 outlets of nine branded supershops in five megacities in Bangladesh. Isolation and identification of E. coli were done based on cultural and biochemical properties, as well as PCR assay. The resistance pattern was determined by the disc diffusion method. ESBL-encoding genes were determined by multiplex PCR. The results showed that 76.1% of samples were positive for E. coli, of which 86% were ESBL producers. All the isolates were multidrug-resistant (MDR). Resistance to 9&ndash;11 and 12&ndash;13 antimicrobial classes was observed in 38.4% and 17.4% isolates, respectively, while only 11.6% were resistant to 3&ndash;5 classes. Possible extensive drug resistance (pXDR) was found in 2.3% of isolates. High single resistance was observed for oxytetracycline (93%) and amoxicillin (91.9%), followed by ampicillin (89.5%), trimethoprim&ndash;sulfamethoxazole, and pefloxacin (88.4%), and tetracycline (84.9%). Most importantly, 89.6% of isolates were resistant to carbapenems. All the isolates were positive for the blaTEM gene. However, the blaSHV and blaCTX-M-2 genes were identified in two ESBL-non producer isolates. None of the isolates carried the blaCTX-M-1 gene. This study provided evidence of the existence of MDR and pXDR ESBL-Ec in frozen chicken meat in Bangladesh, which may pose a risk to human health if the meat is not properly cooked or pickled raw only. This emphasizes the importance of the implementation of good slaughtering and processing practices by the processors.

Infections by methicillin-resistant Staphylococcus aureus (MRSA) are continuously expanding within the community. Chicken meat is usually contaminated by MRSA, and this contaminated chicken meat is an important source of foodborne infections in humans. In this study, a cross-sectional supershop survey was conducted to determine the prevalence and antimicrobial resistance pattern of MRSA in 113 domestic frozen chicken meat samples purchased from nine branded supershops available in five divisional megacities of Bangladesh. The study also focused on the determination of methicillin resistance gene in MRSA isolates. S. aureus was identified by standard culture-based and molecular methods, and subjected to antimicrobial susceptibility testing. MRSA was screened by cefoxitin disk diffusion test. Methicillin resistance gene was identified by PCR. Of samples, 54.9% were positive for S. aureus, and, of these, 37.1% isolates were identified as MRSA. All the isolates were multidrug resistant (MDR): 52.2% were resistant to 6&minus;8 antimicrobial classes, and 47.8% isolates to 9&minus;12 classes. Three (3.2%) isolates of S. aureus were possible extensively drug resistant. The highest rates of resistance were observed against cefoxitin (100%), followed by nalidixic acid, ampicillin and oxacillin (97.7%), colistin (91.3%), amoxicillin-clavulanic acid and amoxicillin (87%), penicillin-G and cloxacillin (82.6%), oxytetracycline (78.3%) and cefixime (73.9%). Screening of methicillin resistance gene revealed that 43.5% isolates of MRSA were positive for mecA gene. The high prevalence of MDR MRSA in frozen chicken meat samples in this study emphasizes the need for better sanitary education of food handlers in hygienic practices focusing on their potential role as reservoirs and spreaders of MRSA.

Multidrug resistant extended-spectrum &beta;-lactamase (ESBL)-producing Escherichia coli is considered a serious concern to public health worldwide including Bangladesh, and chicken meat is recognized as an important reservoir of ESBL-Ec dissemination to humans. Therefore, this study aimed to determine the prevalence, and phenotypic and genotypic antimicrobial resistance pattern of ESBL-producing Escherichia coli (ESBL-Ec) in frozen chicken meat. A total of 113 frozen chicken meat samples were purchased from 40 outlets of 9 branded supershops in five megacities in Bangladesh. Isolation and identification of Escherichia coli were done based on cultural, biochemical properties and PCR assay. The resistance pattern was determined by disk diffusion method. ESBL-encoding genes were determined by multiplex PCR. The results showed that 76.1% samples were positive for Escherichia coli, of which 86% were ESBL producers. All the isolates were multidrug-resistant (MDR). Resistance to 9&ndash;11 and 12&ndash;13 antimicrobial classes was observed in 38.4% and 17.4% isolates, respectively while only 11.6% were resistant to 3&ndash;5 classes. The possible extensively drug resistance (pXDR) was found in 2.3% isolates. The high single resistance was observed for oxytetracycline (93%) and amoxicillin (91.9%), followed by ampicillin (89.5%), trimethoprim-sulphamethoxazole and pefloxacin (88.4%), and tetracycline (84.9%). Most importantly, 89.6% of isolates were resistant to carbapenems. All the isolates were positive for blaTEM gene. However, the blaSHV and blaCTX-M-2 genes were identified in two ESBL-non producer isolates. None of the isolates were carried blaCTX-M-1 gene. This study provided evidence of wide dissemination of MDR and existence of pXDR ESBL-Ec in frozen chicken meat in Bangladesh. Our data clearly indicated that frozen chicken meat is, at the present time, the most significant known food source of ESBL-Ec to which peoples are regularly exposed.

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