Detection of extended spectrum beta-lactamase genes in strains of Escherichia coli and Klebsiella pneumoniae isolated from recreational water and tertiary hospital waste water in Zaria, Nigeria

Molecular detection of Shiga toxin and extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from sheep and goats

BACKGROUND

The Shiga toxin (Stx)-producing Escherichia coli (STEC) have become important global public health concerns. This study investigated the prevalence, antimicrobial resistance profile, and extended-spectrum beta-lactamase-producing E. coli in sheep and goat faeces.

METHODS AND RESULTS

A total of 53 E. coli isolates were confirmed by PCR targeting the uidA [β-D glucuronidase] gene. The Shiga toxin genes stx1 and stx2, as well as bfpA, vir, eaeA, lt and aafII virulence genes, were detected in this study. Of the 53 isolates confirmed to be STEC, 100% were positive for stx2 and 47.2% for stx1. Three isolates possessed a combination of stx1 + stx2 + eaeA, while four isolates harboured stx1 + stx2 + vir virulence genes. The isolates displayed phenotypic antimicrobial resistance against erythromycin (66.04%), colistin sulphate (43.4%), chloramphenicol (9.4%) and ciprofloxacin (1.9%). A total of 28.8% of the strains were phenotypically considered ESBL producers and contained the beta-lactamase blaCTX-M-9 and blaCTX-M-25 gene groups. A larger proportion of the E. coli strains (86.8%) contained the antibiotic sulphonamide resistant (sulII) gene, while 62.3%, 62.3%, 52.8%, 43.4%, 41.5%, 20.8%, 18.9%, 11.3%, 11.3%, 9.4%, 9.4% and 5.7% possessed mcr-4, floR, mcr-1, tet(A), sulI, tet(O), tet(W), parC, mcr-2, ampC 5, qnrS and ermB genes, respectively. Thirteen isolates of the ESBL-producing E. coli were considered multi-drug resistant (MDR). One Shiga toxin (stx2) and two beta-lactamase genes (blaCTX-M-9 and blaCTX-M-25 groups) were present in 16 isolates. In conclusion, the E. coli isolates from the small stock in this study contained a large array of high antibiotic resistance and virulence profiles.

CONCLUSIONS

Our findings highlight the importance of sheep and goats as sources of virulence genes and MDR E. coli. From a public health and veterinary medicine perspective, the characterization of ESBL producers originating from small livestock (sheep and goats) is crucial due to their close contact with humans.

Wastewater from healthcare centers in Burkina Faso is a source of ESBL, AmpC-β-lactamase and carbapenemase-producing Escherichia coli and Klebsiella pneumoniae

BACKGROUND

Extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC-β-lactamase and carbapenemase-producing Escherichia coli and Klebsiella pneumoniae have spread into the environment worldwide posing a potential public health threat. However, the prevalence data for low- and middle-income countries are still scarce. The aim of this study was to evaluate the presence of ESBL, AmpC-β-lactamase and carbapenemase-producing and multidrug-resistant E. coli and K. pneumoniae in wastewaters from healthcare centers in Burkina Faso.

RESULTS

Eighty-four (84) wastewater samples were collected from five healthcare centers and plated on selective ESBL ChromAgar. E. coli and Klebsiella pneumoniae isolates were identified using API20E. ESBL-producing bacteria were detected in 97.6% of the samples and their average concentration per hospital ranged from 1.10 × 105 to 5.23 × 106 CFU/mL. Out of 170 putative ESBL-producing isolates (64% of them were E. coli) and 51 putative AmpC-β-lactamase-producing isolates, 95% and 45% were confirmed, respectively. Carbapenemase production was detected in 10 isolates, of which 6 were NDM producers, 3 were OXA-48 producers and 1 was NDM and OXA-48 producer. All isolates were multidrug resistant and, moreover, all of them were resistant to all tested β-lactams. Resistance to ESBL inhibitors was also common, up to 66% in E. coli and 62% in K. pneumoniae. Amikacin, fosfomycin and nitrofurantoin were the antibiotics to which the least resistance was detected.

CONCLUSIONS

This study showed that wastewater from healthcare centers constitutes a reservoir of multidrug-resistant bacteria in Burkina Faso, including carbapenemase producers. Untreated healthcare wastewater entering the environment exposes people and animals to infections caused by these multi-resistant bacteria, which are difficult to treat, especially in the resource-poor settings.