Comparison of antibiotic resistant Escherichia coli obtained from drinking water sources in northern Tanzania: a cross-sectional study.
Antimicrobial resistance (AMR) is a growing and significant threat to public health on a global scale. Escherichia coli comprises Gram-negative, fecal-borne pathogenic and commensal bacteria that are frequently associated with antibiotic resistance. AMR E. coli can be ingested via food, water and direct contact with fecal contamination.



We estimated the prevalence of AMR Escherichia coli from select drinking water sources in northern Tanzania. Water samples (n = 155) were collected and plated onto Hi-Crome E. coli and MacConkey agar. Presumptive E. coli were confirmed by using a uidA PCR assay. Antibiotic susceptibility breakpoint assays were used to determine the resistance patterns of each isolate for 10 antibiotics. Isolates were also characterized by select PCR genotyping and macro-restriction digest assays.



E. coli was isolated from 71 % of the water samples, and of the 1819 E. coli tested, 46.9 % were resistant to one or more antibiotics. Resistance to ampicillin, streptomycin, sulfamethoxazole, tetracycline, and trimethoprim was significantly higher (15-30 %) compared to other tested antibiotics (0-6 %; P < 0.05). Of the β-lactam-resistant isolates, blaTEM-1was predominant (67 %) followed by blaCTX-M(17.7 %) and blaSHV-1(6.0 %). Among the tetracycline-resistant isolates, tet(A) was predominant (57.4 %) followed by tet(B) (24.0 %). E. coli isolates obtained from these water sources were genetically diverse with few matching macro-restriction digest patterns.



Water supplies in northern Tanzania may be a source of AMR E. coli for people and animals. Further studies are needed to identify the source of these contaminants and devise effective intervention strategies.
Nelson Mandela African Institution of Science and Technology, 447, Arusha, Tanzania. beatus.lyimo@nm-aist.ac.tz.
Beatus
B
Lyimo
Nelson Mandela African Institution of Science and Technology, 447, Arusha, Tanzania.
Joram
J
Buza
Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, 99164, USA.
Murugan
M
Subbiah
One Health Institute, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
Woutrina
W
Smith
Nelson Mandela African Institution of Science and Technology, 447, Arusha, Tanzania.|Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, 99164, USA.
Douglas R
DR
Call
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D060766:Drinking Water / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D013636:Tanzania; D013753:Tetracycline Resistance; D014871:Water Microbiology; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D060766:Drinking Water; D047090:beta-Lactams; D001618:beta-Lactamases
Antibiotic resistance; Low-income country; Tanzania; Water quality