Nanopore sequencing for identification and characterization of antimicrobial-resistant Escherichia coli and Salmonella spp. from tilapia and shrimp sold at wet markets in Dhaka, Bangladesh.

Wet markets in low-and middle-income countries are often reported to have inadequate sanitation resulting in fecal contamination of sold produce. Consumption of contaminated wet market-sourced foods has been linked to individual illness and disease outbreaks. This pilot study, conducted in two major wet markets in Dhaka city, Bangladesh during a 4-month period in 2021 aimed to assess the occurrence and characteristics of Escherichia coli and non-typhoidal Salmonella spp. (NTS) from tilapia (Oreochromis niloticus) and shrimp (Penaeus monodon). Fifty-four individuals of each species were collected. The identity of the bacterial isolates was confirmed by PCR and their susceptibility toward 15 antimicrobials was tested by disk diffusion. The whole genome of 15 E. coli and nine Salmonella spp. were sequenced using Oxford Nanopore Technology. E. coli was present in 60-74% of tilapia muscle tissue and 41-44% of shrimp muscle tissue. Salmonella spp. was found in skin (29%) and gills (26%) of tilapia, and occasionally in muscle and intestinal samples of shrimp. The E. coli had several Multilocus sequence typing and serotypes and limited antimicrobial resistance (AMR) determinants, such as point mutations on glpT and pmrB. One E. coli (BD17) from tilapia carried resistance genes for beta-lactams, quinolones, and tetracycline. All the E. coli belonged to commensal phylogroups B1 and A and showed no Shiga-toxin and other virulence genes, confirming their commensal non-pathogenic status. Among the Salmonella isolates, five belonged to Kentucky serovar and had similar AMR genes and phenotypic resistance patterns. Three strains of this serovar were ST198, often associated with human disease, carried the same resistance genes, and were genetically related to strains from the region. The two undetermined sequence types of S. Kentucky were distantly related and positioned in a separate phylogenetic clade. Two Brunei serovar isolates, one Augustenborg isolate, and one Hartford isolate showed different resistance profiles. This study revealed high fecal contamination levels in tilapia and shrimp sold at two main wet markets in Dhaka. Together with the occurrence of Salmonella spp., including S. Kentucky ST198, a well-known human pathogen, these results stress the need to improve hygienic practices and sanitation standards at markets to improve food safety and protect consumer health.

Knowledge, Attitudes and Practices Regarding Antibiotic Use and Resistance among Veterinary Students in Bangladesh.

The use of antibiotics in animals for both therapeutic and non-therapeutic purposes is a major driver of the emergence and spread of antimicrobial resistance (AMR). While several studies have investigated prescription and consumption patterns in humans, little attention has been paid to the veterinary sector. A cross-sectional study was conducted in 3002 veterinary students (VS) and non-medical students (NMS) from 12 universities in Bangladesh to explore their knowledge, attitudes and practices (KAP) about antibiotics and AMR using a self-administered questionnaire, and assess the influence of the veterinary curriculum. KAP regarding antibiotic use and AMR was significantly higher in veterinary than non-medical students, and in first-year than final-year students. However, gaps in knowledge and practices were highlighted, suggesting deficiencies in training. Moreover, final-year veterinary students were found to be more likely than first-year students to use antibiotics without instructions, which could indicate deficiencies in their curriculum. Although the study suggested a positive impact of the veterinary curriculum on KAP about antibiotics and AMR in Bangladesh, critical gaps remain that are likely to contribute to inadequate use in their future practice. Therefore, there is scope for improving educational programs on AMR in professional curricula.

Antibiotic-resistant Escherichia coli in deer and nearby water sources at Safari parks in Bangladesh.

BACKGROUND AND AIM: The emergence and rapid dissemination of multidrug-resistant (MDR) bacteria in different ecosystems is a growing concern to human health, animal health, and the environment in recent years. The study aimed to determine the antibiotic resistance in Escherichia coli from deer and nearby water sources at two different Safari parks in Bangladesh. MATERIALS AND METHODS: A number of 55 fresh fecal samples of deer and six water samples from nearby lakes were collected from two Safari parks. Samples were processed, cultured, and carried out biochemical tests for E. coli. The antibiotic susceptibility was determined by disk diffusion method. To identify the resistance genes, polymerase chain reaction was performed. RESULTS: A total of 32 E. coli isolates from 55 fecal samples and 6 of 6 E. coli isolates from lake water were isolated. From fecal E. coli isolates, ampicillin and sulfamethoxazole were 90.63% (n=29/32) resistant and 87.5% (n=28/32) were resistant to tetracycline and nalidixic acid. High resistance was also observed to other antibiotics. On the contrary, all E. coli isolates from water sources were 100% (n=6/6) resistant to ampicillin, tetracycline, sulfamethoxazole, and nalidixic acid. MDR was revealed in all water samples, whereas 96.88% (n=31/32) was found in fecal isolates. A number of bla TEM, tet A, and Sul2 genes were detected from both isolates. CONCLUSION: This study for the 1st time highlights, a significant proportion of E. coli isolates in wildlife deer and nearby water sources were MDR in Bangladesh.

Antibiotic resistance of Escherichia coli isolated from broilers sold at live bird markets in Chattogram, Bangladesh.

OBJECTIVE: The present study was carried out to appraise the antibiotic resistance and to detect some of the target resistant genes in Escherichia coli (E. coli) isolated from apparently healthy broilers. MATERIALS AND METHODS: Cloacal swab samples (n = 60) were collected from apparently healthy broilers (n = 60) sold at two different live bird markets (LBMs) of Chattogram, Bangladesh. Isolation and identification of the Escherichia coli was done by the following standard bacteriological techniques followed by biochemical tests. The antibiotic susceptibility of E. coli isolates was determined by the disk diffusion method. The antibiotic resistant genes were detected by polymerase chain reaction (PCR) using specific primers. RESULTS: The overall prevalence of E. coli in broilers was 61.67% (n = 37/60) (95% CI = 49-72.93). The antibiogram study showed that the isolates were 100% resistant to ampicillin and tetracycline followed by sulfomethoxazole-trimethoprim (94.59%, n = 35/37) and nalidixic acid (91.89%, n = 34/37). To the contrary, 56.76% (n = 21/37) isolates were sensitive to both ceftriaxone and gentamicin followed by colistin (48.65%, n = 18/37). All of E. coli isolates were multidrug resistant (MDR) and carried bla TEM, tetA, and Sul2 genes. CONCLUSION: The presence of MDR genes in E. coli isolates in broilers could pose a serious public health threat.

Antibiotic resistance of Escherichia coli isolated from captive Bengal tigers at Safari parks in Bangladesh.

OBJECTIVES: The present study was carried out to assess the antibiotic resistance and to identify the resistance genes in Escherichia coli from captive Bengal tigers at two Safari parks in Bangladesh. MATERIALS AND METHODS: A number of 24 environmental fecal swab samples of Bengal tigers were collected from two different Safari parks in Bangladesh. For the isolation of E. coli, samples were submitted to a number of bacteriological screening and biochemical tests. The antibiotic susceptibility of E. coli isolates was determined by disk diffusion method. RESULTS: Results demonstrated that 18 environmental fecal samples were positive to E. coli in bacteriological screening and biochemical test. The overall prevalence of E. coli in Bengal tiger was 75% (n = 18/24). The antibiogram study unveiled that all the isolates were resistant to ampicillin. Sulfamethoxazole-trimethoprim, nalidixic acid, and tetracycline were 89% (n = 16/18) resistant. On the contrary, 100% (n = 18/18) of the isolates were sensitive to colistin sulfate. bla TEM was detected in 78% (n = 14/18) ampicillin-resistant isolates, whereas sul2 was found in 31% (n = 5/16) of the sulfamethoxazole-trimethoprim-resistant isolates. CONCLUSION: This study, first time in Bangladesh, highlights a significant proportion of environmental fecal samples from captive Bengal tigers at Safari parks harboring antibiotic resistant E. coli. Transmission of resistant E. coli from Bengal tigers to humans and the environment could pose a public health risk at Safari parks in Bangladesh.