IncF Plasmids Are Commonly Carried by Antibiotic Resistant Escherichia coli Isolated from Drinking Water Sources in Northern Tanzania.

Beatus Lyimo,Sylivester Temba,Murugan Subbiah,Honest Kipasika,Woutrina Smith,Douglas R Call,Joram Buza

doi:10.1155/2016/3103672

Abstract

The aim of this study was to identify the replicon types of plasmids, conjugation efficiencies, and the complement of antibiotic resistance genes for a panel of multidrug resistant E. coli isolates from surface waters in northern Tanzania. Standard membrane filtration was used to isolate and uidA PCR was used to confirm the identity of strains as E. coli. Antibiotic susceptibility was determined by breakpoint assay and plasmid conjugation was determined by filter-mating experiments. PCR and sequencing were used to identify resistance genes and PCR-based replicon typing was used to determine plasmid types. Filter mating experiments indicated conjugation efficiencies ranged from 10−1 to 10−7. Over 80% of the donor cells successfully passed their resistance traits and eleven different replicon types were detected (IncI1, FIC, P, FIIA, A/C, FIB, FIA, H12, K/B B/O, and N). IncF plasmids were most commonly detected (49% of isolates), followed by types IncI1 and IncA/C. Detection of these public health-relevant conjugative plasmids and antibiotic resistant traits in Tanzanian water suggests the possible pollution of these water sources from human, livestock, and wild animal wastes and also shows the potential of these water sources in the maintenance and transmission of these resistance traits between environments, animals, and people.

Highlights

Increased mortality and morbidity due to antibiotic treatment failure make antimicrobial resistance (AMR) one of the 21st century’s major global public health challenges [1]
IncF replicon types (IncF IA, IB, IC, and IIA) were predominant (49%) and were mainly associated with E. coli isolates that were resistant to ampicillin, streptomycin, sulfonamide, tetracycline, and trimethoprim
Our study shows that E. coli isolated from Tanzanian water sources harbor multiple plasmids belonging to major plasmid replicon types such as IncF, A/C, l1, and N

Summary

Introduction

Increased mortality and morbidity due to antibiotic treatment failure make antimicrobial resistance (AMR) one of the 21st century’s major global public health challenges [1]. Tanzanian hospitals have reported a high proportion (80%–90%) of clinical E. coli isolates that are resistant to antibiotics such as ampicillin, cotrimoxazole, tetracycline, gentamicin, and amoxicillin/clavulanic acid. These bacteria infect people within a healthcare system where, in most cases, there are no laboratory diagnostics to guide antibiotic treatment [8,9,10]. Another study reported a high number of antibiotic resistant E. coli, possessing resistance to cephalosporins, from free-range buffalo, zebra, and wildebeest [11] These animals were located in mixed grazing areas with potential contact with people and livestock. Contaminated water was suspected as the source of resistant bacteria found in these

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