Evaluation of bottled drinking water and occurrence of multidrug-resistance and biofilm producing bacteria in Nepal.

Health consequences arising from unsafe drinking water and water insecurity lead to increased reliance on usage of bottled water. Biofilm-producing antibiotic-resistant bacteria in bottled water may pose a risk to public health. This study aims to assess the quality of bottled drinking water with a focus on biofilm-producing and drug-resistant coliform. We analyzed 60 bottled water samples of 30 different brands purchased from Kathmandu for physicochemical and microbial analysis. The parameters pH, iron, total coliform count, Escherichia coli count, and fecal coliform count exceeded National Drinking Water Quality Standards, 2022 in 30.00%, 16.67%, 66.67%, 23.33%, and 16.67% of samples, respectively. Water quality index measurement showed 36.67% and 6.67% of bottled water samples were categorized as grade A and grade B indicating excellent and good water quality, respectively. However, 56.67% of bottled water samples fall under grade E meaning unsuitable for drinking. Among 14 coliform isolates, 85.71% and 14.29% were identified as E. coli and Klebsiella spp, respectively. The antibiotic susceptibility testing revealed that 28.57% of the isolates were multidrug-resistant and Gentamicin resistant isolates comprised 71.43%. However, none of the isolates were carbapenem (meropenem) resistant. In this study, 42.87% of the isolates were found biofilm producers with 14.29% each of strong, moderate, and weak biofilm producers. The genetic potential of biofilm-producing capacity of the isolates was assessed by Polymerase Chain Reaction amplification of bcsA and csgD genes. Our results showed that 66.67% and 50.00% of the isolates harbored bcsA and csgD genes, respectively. This study highlights potential public health hazards associated with the consumption of bottled water containing biofilm-producing and drug-resistant bacteria in Nepal.

Prevalence of Colistin-Resistant Escherichia coli from Poultry in South Asian Developing Countries.

BACKGROUND: Antimicrobial resistance has become a huge problem in animal and public health worldwide. Inadvertent use of antibiotics in poultry has led to the emergence of resistance against many antibiotics, even to last resort of drugs like colistin. AIM: This study aimed to provide uniform quantitative estimate on the percentage prevalence of E. coli as well as to analyze their colistin resistance in poultry in South Asian developing countries. METHODS: Two electronic databases, PubMed and Research4Life, were used to search studies as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The pooled data on the prevalence of E. coli and colistin resistance were analyzed. RESULTS: In the meta-analysis of 9 studies in South Asian region (Nepal, Bangladesh, Pakistan, and India), the pooled prevalence of E. coli was 73% (95% CI, 0.549-0.916). The pooled prevalence of colistin resistance against E. coli from poultry was found to be 28% (95% CI, 0.158-0.438). CONCLUSION: There is high prevalence of E. coli and their resistance rate against colistin in poultry. Therefore, antimicrobials in raising livestock should be supervised.

Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal.

Background: Plasmid-mediated resistance to the colistin in poultry is considered as an emerging problem worldwide. While poultry constitutes the major industry in Nepal, there is a paucity of evidence on colistin resistance in Escherichia coli isolates causing natural infections in poultry. This study aimed to explore the prevalence of plasmid-mediated colistin resistance gene, mcr-1 in E. coli isolated from liver samples of dead poultry suspected of E. coli infections. Methods: A total of two hundred and seventy liver samples (227 broilers and 43 layers) from dead poultry suspected of colibacillosis were collected from post-mortem in the Central Veterinary Laboratory (CVL), Kathmandu, between 1 February and 31 July 2019. The specimens were processed to isolate and identify E. coli; an antimicrobial susceptibility test (AST) using disk diffusion method was performed with 12 different antibiotics: Amikacin (30 µg), ampicillin (10 µg), ciprofloxacin (5 µg), chloramphenicol (30 µg), cefoxitin (30 µg), ceftazidime (30 µg), ceftriaxone (30 µg), cotrimoxazole (25 µg), gentamicin (10 µg), imipenem (10 µg), levofloxacin (5 µg) and tetracycline (30 µg). Colistin resistance was determined by agar dilution method and colistin-resistant strains were further screened for plasmid-mediated mcr-1 gene, using conventional polymerase chain reaction (PCR). Results: Out of 270 liver samples, 53.3% (144/270) showed growth of E. coli. The highest number (54%; 109/202) of E. coli isolates was obtained in the liver samples from poultry birds (of both types) aged less than forty days. In AST, 95.1% (137/144) and 82.6% (119/144) of E. coli isolates were resistant against tetracycline and ciprofloxacin, respectively, while 13.2% (19/144) and 25.7% (37/144) isolates were resistant to cefoxitin and imipenem, respectively. In the same assay, 76.4% (110/144) E. coli isolates were multi-drug resistant (MDR). The phenotypic prevalence of colistin resistance was 28.5% (41/144). In the PCR assay, 43.9% (18/41) of colistin-resistant isolates were screened positive for plasmid-mediated mcr-1. Conclusion: The high prevalence of mcr-1 in colistin-resistant E. coli isolates in our study is a cause of concern for the probable coming emergence of colistin resistance in human pathogens, due to horizontal transfer of resistant genes from poultry to human isolates.