Characterization of Escherichia coli from Water and Food Sold on the Streets of Maputo: Molecular Typing, Virulence Genes, and Antibiotic Resistance

Abstract

The aim of this study was to investigate the pathogenic potential and antibiotic resistance of 59 Escherichia coli isolates from ready-to-eat (RTE) street food (n = 31) and drinking water (n = 28) sold in the city of Maputo, Mozambique. The isolates were characterized by XbaI subtyping analysis via pulsed field gel electrophoresis. Multiplex PCRs were performed targeting five virulence genes (stx, lt, st, astA, and eae) and three groups of antibiotic-resistant genes, namely ß-lactamases (extended-spectrum ß-lactamase and AmpC), tetracycline (tetA, tetB, and tetM) and sulfamethoxazole/trimethoprim (sul1, sul2, and sul3). The stx virulence gene, encoding the Shiga/Vero (VT) toxin produced by the verotoxin-producing E. coli (VTEC), was identified with similar frequency in isolates from food (5/31) and water (6/28). The highest percentages of resistant isolates from food and water were found for ß-lactams imipenem (35.5 and 39.3%, respectively) and ampicillin (39.3 and 46.4%, respectively). Multidrug resistance was observed in 31.3% of the isolates, being higher in E. coli isolates from water (45.5%) compared to RTE street food isolates (19.2%). Virulence genes were detected in 73% of the multidrug-resistant isolates. Concerning antibiotic-resistant genes, ESBL was the most frequent (57.7%) among β-lactamases while tetA was the most frequent (50%) among non-β-lactamases.

Distribution of antibiotic resistance genes and antibiotic residues in drinking water production facilities: Links to bacterial community

“…The MOX gene was only detected in raw water 1 in NW-E. DHA was also absent in NW-C DWPF, but it was detected in raw than treated water of NW-E DWPF. Although not extensively featured in environmental studies, these genes have been reported in various niches [ 13 , 52 – 54 ]. pAmpCs are widespread in various niches where their effects may be undesirable for human health [ 51 ] and they are underexplored in the DWPFs.…”

“…Aquatic environments are important vectors of antibiotic resistance, which provide favourable conditions for bacterial growth and spread antibiotic resistance genes (ARGs) via horizontal gene transfer to other species [ 10 , 11 ]. However, in South Africa, antibiotic resistance is not monitored and regulated in aquatic environments despite being reported in drinking water [ 12 , 13 ]. Furthermore, studies addressing antibiotic resistance in drinking water focus on detecting ARGs and not so much on quantifying ARGs and antibiotic residues.…”

Susceptibility antibiotic screening reveals high rates of multidrug resistance of Salmonella, Shigella and Campylobacter in HIV infected and uninfected patients from Mozambique

“…Overall, the high prevalence of antibiotic resistance findings in this study is likely due to multiple factors, including unrestricted and inappropriate use of antibiotics through self-medication, the sale of antibiotics in informal markets [ 35 , 36 ], cross-contamination through environmental and food sources [ 33 , 37 , 38 ] and the use of antibiotics in animal husbandry without proper guidance from healthcare professionals [ 39 – 42 ].…”

Enterotoxin- and Antibiotic-Resistance-Encoding Genes Are Present in Both Coagulase-Positive and Coagulase-Negative Foodborne Staphylococcus Strains

“…When associated with poor hygiene practices by handlers and poor hygienic conditions of the exposure environment, ready-to-eat (RTE) street food presents a potential risk of transmission of staphylococcal strains [31][32][33][34][35][36]. In Maputo, Mozambique, street foods are sold in environments with poor sanitation conditions and lack of potable water, which increases the risk of street food contamination [33,34,37,38].…”

“…When associated with poor hygiene practices by handlers and poor hygienic conditions of the exposure environment, ready-to-eat (RTE) street food presents a potential risk of transmission of staphylococcal strains [31][32][33][34][35][36]. In Maputo, Mozambique, street foods are sold in environments with poor sanitation conditions and lack of potable water, which increases the risk of street food contamination [33,34,37,38]. This study is a follow-up to previous research by [31], and aims to evaluate the antimicrobial resistance profile and the occurrence of both virulence-and antibiotic-resistance genes in 66 coagulase-positive and coagulase-negative Staphylococcus isolates previously recovered from RTE foods sold on the streets of Maputo, Mozambique.…”