Antibiotic Susceptibilities of Enterococcus Species Isolated from Hospital and Domestic Wastewater Effluents in Alice, Eastern Cape Province of South Africa

Abstract

Background: Antimicrobial resistance in microorganisms are on the increase worldwide and are responsible for substantial cases of therapeutic failures. Resistance of species of Enterococcus to antibiotics is linked to their ability to acquire and disseminate antimicrobial resistance determinants in nature, and wastewater treatment plants (WWTPs) are considered to be one of the main reservoirs of such antibiotic resistant bacteria. We therefore determined the antimicrobial resistance and virulence profiles of some common Enterococcus spp that are known to be associated with human infections that were recovered from hospital wastewater and final effluent of the receiving wastewater treatment plant in Alice, Eastern Cape. Methods: Wastewater samples were simultaneously collected from two sites (Victoria hospital and final effluents of a municipal WWTP) in Alice at about one to two weeks interval during the months of July and August 2014. Samples were screened for the isolation of enterococci using standard microbiological methods. The isolates were profiled molecularly after targeted generic identification and speciation for the presence of virulence and antibiotic resistance genes. Results: Out of 66 presumptive isolates, 62 were confirmed to belong to the Enterococcus genusof which 30 were identified to be E. faecalis and 15 E. durans. The remaining isolates were not identified by the primers used in the screening procedure. Out of the six virulence genes that were targeted only three of them; ace, efaA, and gelE were detected. There was a very high phenotypic multiple resistance among the isolates and these were confirmed by genetic analyses. Conclusions: Analyses of the results obtained indicated that hospital wastewater may be one of the sources of antibiotic resistant bacteria to the receiving WWTP. Also, findings revealed that the final effluent discharged into the environment was contaminated with multi-resistant enterococci species thus posing a health hazard to the receiving aquatic environment as these could eventually be transmitted to humans and animals that are exposed to it.

Antibiotic Resistant Bacteria from Treated and Untreated Hospital Wastewater at Ayder Referral Hospital, Mekelle, North Ethiopia

“…The same result was reported from Alice, Eastern Cape province of South Africa [28] and European countries [29] [30], where higher rate of resistance in bacterial isolates from final effluent of wastewater treatment plant was found. Presences of high percentage of drug resistant isolates from the final effluent of WWTP suggest that, hospital wastewater could have contributed massively to the resistances observed among the isolates from the final effluent.…”

Molecular epidemiology and mechanisms of antibiotic resistance inEnterococcusspp.,Staphylococcusspp., andStreptococcusspp. in Africa: a systematic review from a One Health perspective

“…Erm (B) (≥348), vanC ‐2/3 (162), vanB (≥140), vanC (≥120), and strA (≥120) were the major resistance genes. The VAN‐resistant isolates were from patients with hematological malignancies, bacteremia, pigs, wastewater, and underground water . E. faecium ST25 and ST23 and E. faecalis ST23, ST25, and ST780 were resistant clones isolated from sewage water, treated effluent, and hospital waste .…”

“…Resistance genes from Enterococcus spp., Staphylococcus spp., and Streptococcus spp. have been detected in ground and surface water fed by effluents from hospitals and sewage processing plants, as well as runoff from animal farms that use antibiotics . Furthermore, genes that mediate resistance to last‐resort Gram‐positive bacteria–specific antibiotics, such as VAN, have been recovered from raw milk and other animal products, pigs, wild animals (buffalo, zebra, and cattle), waste water, effluents, and patients, which implicates both veterinary and agricultural (over)use of antibiotics as potential sources of antimicrobial resistance genes in humans …”

Physico-Chemical Properties and Microbiological Quality of Borehole Water in Four Crowded Areas of Benin City, Nigeria, During Rainfalls

“…Vancomycin has been used as a first choice drug for the treatment of enterococcal infections until Vancomycin Resistant Enterococci (VRE) arose. Resistance of Enterococcus was associated with the misuse of avoparcin (an analogue of vancomycin, which is used as a growth promoter) in intensive animal rearing and misuse of vancomycin in hospital settings (44,45). Moreover, the use of glycopeptides in the management of community -acquired infections has led to the widespread of vancomycin resistant isolates in the environment (45).…”