Molecular Detection of Antibiotic-Resistant Genes in Pseudomonas aeruginosa from Nonclinical Environment: Public Health Implications in Mthatha, Eastern Cape Province, South Africa.

Grace Emily Okuthe,Clemencia Chaves Lopez,Teke Apalata,Sandeep Vasaikar,Mojisola Clara Hosu

doi:10.1155/2021/8861074

Grace Emily Okuthe, Clemencia Chaves Lopez + Show 3 more

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https://doi.org/10.1155/2021/8861074

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Abstract

Evaluation of resistant profiles and detection of antimicrobial-resistant genes of bacterial pathogens in the nonclinical milieu is imperative to assess the probable risk of dissemination of resistant genes in the environment. This paper sought to identify antibiotic-resistant genes in Pseudomonas aeruginosa from nonclinical sources in Mthatha, Eastern Cape, and evaluate its public health implications. Samples collected from abattoir wastewater and aquatic environment were processed by membrane filtration and cultured on CHROMagarTM Pseudomonas medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL). Molecular characterization of the isolates was confirmed using real-time polymerase chain reaction (rPCR) and selected isolates were further screened for the possibility of harboring antimicrobial resistance genes. Fifty-one Pseudomonas species were recovered from abattoir wastewater and surface water samples, out of which thirty-six strains were Pseudomonas aeruginosa (70.6%). The P. aeruginosa isolates demonstrated resistance to aztreonam (86.1%), ceftazidime (63.9%), piperacillin (58.3%), cefepime (55.6%), imipenem (50%), piperacillin/tazobactam (47.2%), meropenem (41.7%), and levofloxacin (30.6%). Twenty out of thirty-six P. aeruginosa displayed multidrug resistance profiles and were classified as multidrug-resistant (MDR) (55.6%). Most of the bacterial isolates exhibited a high Multiple Antibiotic Resistance (MAR) Index ranging from 0.08 to 0.69 with a mean MAR index of 0.38. In the rPCR analysis of fifteen P. aeruginosa isolates, 14 isolates (93.3%) were detected harboring blaSHV, six isolates (40%) harbored blaTEM, and three isolates (20%) harbored blaCTX-M, being the least occurring ESBL. Results of the current study revealed that P. aeruginosa isolates recovered from nonclinical milieu are resistant to frontline clinically relevant antipseudomonal drugs. This is concerning as it poses a risk to the environment and constitutes a public health threat. Given the public health relevance, the paper recommends monitoring of multidrug-resistant pathogens in effluent environments.

Highlights

Antimicrobial resistance (AMR) is a public health crisis in both human and veterinary medicine [1, 2]. e irrational use of antibiotics in both human medicine and animal production for growth-promoting purposes, metaphylaxis, and prophylaxis has fueled the proliferation and spread of antibiotic-resistant bacteria and resistance genes resulting in aggravated public health and environmental risks [3,4,5]. e threat posed by AMR to human health is concerning in low- to middle-income countries (LMICs)
The 36 strains of P. aeruginosa were selected for further confirmation. ey were confirmed by the real-time amplification of the gyrB gene including the reference strain, ATCC 27853 (Figure 1). e results of antibiotic susceptibility testing of P. aeruginosa strains showed varying levels of resistance
Thirty-six isolates of P. aeruginosa were recovered from abattoir wastewater and surface water

Summary

Introduction

E irrational use of antibiotics in both human medicine and animal production for growth-promoting purposes, metaphylaxis, and prophylaxis has fueled the proliferation and spread of antibiotic-resistant bacteria and resistance genes resulting in aggravated public health and environmental risks [3,4,5]. Is competence for infections and ability for antibiotic resistance has made the organism to be recognized as a threat to public health [9, 10]. Antibiotic usage in the agricultural sector has compounded the spread of resistance in the human community due to the environmental dissemination of transferable resistance genes [12]. E possibility of pathogens from abattoir effluent and animal waste reaching or discharging into water bodies and developing resistance to antibiotics in human infection is a concern. Discharge from abattoir effluent contaminates the environment by introducing pathogens that can affect land and water qualities, endangering human, animal, and aquatic ecosystem’s health and constituting a menace to human health and environmental safety [13]. e possibility of pathogens from abattoir effluent and animal waste reaching or discharging into water bodies and developing resistance to antibiotics in human infection is a concern. is is because these infections are usually difficult to treat and often result in morbidity and mortality especially in the most vulnerable members of the community [14]

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