Prevalence, Species Composition, Antibiogram and Vancomycin Resistant Determinant of Enterococcus spp. Isolated from Wastewater Treatment Plant and its Affected Ecosystems

Document Type : Original Article

Authors

1 Botany Department, Faculty of Science, Port Said University, Port Said, Egypt

2 Department of Botany, Faculty of Science, Port Said University, Port Said, 42524, Egypt.

3 Microbiology and Immunology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt

4 Botany and Microbiology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt

Abstract

Most local and international legislation neglect the risk of transferring pathogenic bacteria, especially those with multiple antibiotic resistance, and causal genes. Egypt lacks data on the prevalence of MDR/VRE Enterococci in wastewater reclaimed soils or aquatic ecosystems receiving treated wastewater. Therefore, this study goals are to study the prevalence of MDR/VRE Enterococci in wastewater treatment system, reclaimed soil and effluent receiving water bodies. Monthly schemes were implemented in 2018 and 2019 to collect samples of raw and treated sewage, sludge, reclaimed soil, drainage canal, and downstream lake. Samples for total enterococci were analyzed using the Multiple Tube method. Enterococci isolates were purified and confirmed to species level by PCR. Antibiotics sensitivity testing was performed by Disk Diffusion method. Ampicillin, chloramphenicol, ciprofloxacin, gentamicin, erythromycin, tetracycline, and vancomycin were tested for antibiotic susceptibility using the Kirby bauer method. In addition, vanA and vanB genes were screened in the confirmed VRE strains. Although, the wastewater treatment plant was able to eliminate 98% of total enterococci, the discharged or reclaimed effluent still containing 3 LOG MPN/ 100 mL of enterococci, mostly (64%) MDR Enterococcus faecalis and Enterococcus faecium with MARI >0.2. VRE was detected in 7% of samples, including reclaimed water and receiving water bodies regimen was not effective in removing VRE and multi-antibiotic-resistant enterococci (MARI). These findings demonstrate that MDR/VRE enterococci are released into the environment via wastewater, where they potentially pose a concern to human health.

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