Antimicrobial susceptibility profile of selected Enterobacteriaceae in wastewater samples from health facilities, abattoir, downstream rivers and a WWTP in Addis Ababa, Ethiopia

Abstract

Background Evaluation of antimicrobial susceptibility profile of various bacterial pathogens in the health facilities, abattoirs and related environment is important to assess potential risk of dissemination of resistant pathogens to the environment. There is limited information about antimicrobial susceptibility profile of common Enterobacteriaceae in waste water samples from hospitals, abattoirs and the downstream water bodies in Addis Ababa. The present study assessed antimicrobial susceptibility of bacteria belonging to the family Enterobacteriaceae isolated from wastewater samples (WWS) of two hospitals: Tikur Anbessa Specialized Hospital (TASH) and Minilik II hospital, a wastewater treatment plant (WWTP) and an abattoir, and downstream rivers in Addis Ababa. Results A total of 54 bacterial isolates belonging to 6 species were identified: E.coli (32%), Salmonella 23%), Klebsiella pneumonia (15%), Enterobacter aerogenes (11%), Citrobacter (7%), Klebsiella oxytoca (6%) and Enterobacter cloacae (6%), respectively. Two strains of Citrobacter spp. isolated from TASH wastewater sample (WWS) were resistant to all 12 antimicrobials tested whereas an E. coli isolate from the same source was resistant to 11 antimicrobials. All isolates were resistant to 2 or more antimicrobials tested. Multi-drug resistance (MDR) to several antimicrobials was recorded, particularly in isolates obtained from hospital WWS and it was more common in Citrobacter and E. coli isolates. Extended spectrum betalactamase (ESBL) production was detected in 27.3% of MDR isolates, all of them obtained from hospital effluents whereas none of the isolates were carbapenemase producers. Conclusion The present study revealed that Enterobacteriaceae in wastewater from hospitals, abattoir and downstream water bodies are resistant to commonly used antimicrobials. Hospital effluents contained more of MDR bacteria, posing significant public health threat through dissemination to the downstream water bodies.

Occurrence, identification and antibiogram signatures of selected Enterobacteriaceae from Tsomo and Tyhume rivers in the Eastern Cape Province, Republic of South Africa

“…The MALDI-TOF confirmation of the identities of the presumptive Enterobacteriaceae isolated revealed that E. coli was mostly detected in this study with a 33% detection rate. A similar result was reported by (10) and (11). This high detection rate of E. coli when considered with the other members of Enterobacteriaceae detected is, however, unsurprising as E. coli is a common commensal organism in the gastrointestinal tracts of animals as well as humans.…”

“…Titilawo and colleagues (9) also reported multiple antimicrobial resistances ranging from three to nine antimicrobials from E. coli isolated from some rivers in Nigeria. Toroglu and colleagues (62) reported MDR in the members of Enterobacteriaceae recovered from some rivers in Turkey (62) with similar results being reported by(63) and(11) in the rivers of Bangladesh and Ethiopia respectively.Various human activities contributes to the diverse MARPs observed in rivers. One of the most important being the discharge of wastewaters as rivers are the primary recipients of effluents from sewage(11,64).…”

“…Toroglu and colleagues (62) reported MDR in the members of Enterobacteriaceae recovered from some rivers in Turkey (62) with similar results being reported by(63) and(11) in the rivers of Bangladesh and Ethiopia respectively.Various human activities contributes to the diverse MARPs observed in rivers. One of the most important being the discharge of wastewaters as rivers are the primary recipients of effluents from sewage(11,64). It is rather unfortunate that majority of the antimicrobial agents when used are not fully metabolised in the body and are therefore released directly into the hospital sewage system or to the municipal wastewater(5,23).…”

“…This discovery, therefore, implicates the environment as the origin of antimicrobial resistance evolution (5)(6)(7)(8). In different regions of the world, there have been various studies which have carried out investigation into the occurrence of antibiotic-resistant bacteria (ARB) in various aquatic milieu (5,(9)(10)(11)(12). Since the first discovery of antibiotics over eight decades ago, they have been used to save millions of lives in treating bacterial infections and diseases.…”

Trends, new insights and perspectives in the treatment of hospital effluents

“…Over the last two to three years, interesting investigations on the treatment of hospital effluent have been carried out worldwide: consolidated and modified/enhanced technologies as well as new solutions have been tested on the effluent of specific wards, the whole healthcare structure, nursing homes specialised in psychiatric diseases ( 22 ), ( 23 ) or service units such as laundry ( 24 ). They have not only taken place in countries where studies or investigations on hospital effluent have also been carried out, but also in new ones, such as Ethiopia ( 25 ), Columbia ( 5 ), India ( 26 ), Iran ( 27 ), ( 28 ), Costa Rica ( 29 ) and Thailand ( 21 ). This demonstrates the increasing interest in the management and treatment of healthcare structure effluent by researchers, practitioners, policy makers and administrative staff, both in developed and developing countries.…”