Antibiotic-resistant heterotrophic plate count bacteria and amoeba-resistant bacteria in aquifers of the Mooi River, North West province, South Africa

Abstract

Groundwater in the Mooi River catchment is prone to mining, agricultural, municipal and septic tank pollution. In this study physico-chemical and microbiological parameters were determined using appropriate methods. Bacterial isolates were identified by 16S rRNA sequencing (heterotrophic plate count (HPC) bacteria and amoeba-resistant bacteria (ARB)) and multiplex polymerase chain reaction (Escherichia coli). Antibiotic resistance tests were also performed. Physico-chemical parameters were generally within target water quality ranges for drinking water. HPC bacteria ranged between 10(5) and 10(7) colony-forming units (cfu)/ml. E. coli were enumerated from Trimpark, School and Cemetery. The Blaauwbank borehole was negative for faecal streptococci. Pseudomonas spp. were most abundant in the bulk water. Opportunistic pathogens isolated included Pseudomonas aeruginosa, Acinetobacter, Aeromonas, Alcaligenes, Flavobacterium, Bacillus cereus and Mycobacterium spp. Varying patterns of antibiotic resistance were observed. Most HPC bacterial isolates were resistant to cephalothin and/or amoxicillin and a few were resistant to erythromycin and streptomycin. Pseudomonas spp. was also the most abundant ARB. Other ARBs included Alcaligenes faecalis, Ochrobactrum sp. and Achromobacter sp. ARBs were resistant to streptomycin, chloramphenicol, cephalothin, and/or amoxicillin compared to HPCs. The presence of E. coli and ARB in these groundwater sources indicates potential human health risks. These risks should be further investigated and quantified, and groundwater should be treated before use.

The ‘thanato-resistome’ - The funeral industry as a potential reservoir of antibiotic resistance: Early insights and perspectives

“…For example, AR in wastewater and drinking water systems, and even soils has attracted significant research attention, as evidenced by several research articles, including reviews ( Gwenzi et al, 2018 ; Sanganyado and Gwenzi, 2019 ). By contrast, only a handful of papers are available on AR in the whole funeral industry, spanning several compartments, including autopsy, thanatopraxy and cemeteries ( Carstens, 2012 ; Carstens et al, 2014 ; Abia et al, 2018 , Abia et al, 2019 ). Yet similar to AR in the funeral industry, quantitative data directly linked the occurrence of AR in wastewaters and drinking water to human health risks are scarce.…”

“…Pharmaceuticals, antibiotics and inorganic contaminants have been detected in environmental media from cemeteries, including surface water and groundwater ( Carstens, 2012 ; Carstens et al, 2014 ; Paíga and Delerue-Matos, 2016 ; Fiedler et al, 2018 ; Abia et al, 2018 , Abia et al, 2019 ). Pharmaceuticals, nutrients and trace metals are well-known for inducing and co-selecting for the emergence of antibiotic resistance ( Knapp et al, 2016 ; Zhao et al, 2017 ).…”

“…Pharmaceuticals, nutrients and trace metals are well-known for inducing and co-selecting for the emergence of antibiotic resistance ( Knapp et al, 2016 ; Zhao et al, 2017 ). Accordingly, antibiotic resistant bacteria and their resistance genes have been reported in environmental media from cemeteries, and a number of studies conducted in cemeteries in South Africa are quite instructive in this regard ( Carstens, 2012 ; Carstens et al, 2014 ; Abia et al, 2018 , Abia et al, 2019 ).…”

“…In an independent study conducted in aquifers in two catchments in the North Western province in South Africa, six isolates of Pseudomonas , Leifsonia , Comamonas , and Brevundimonas spp. from surface and groundwater samples were tested for resistance to eight antibiotics ( Carstens, 2012 ; Carstens et al, 2014 ). The eight antibiotics and their corresponding concentrations were: (1) Amoxicillin (A): 10 μg, (2) cephalothin (KF): 30 μg, (3) ciprofloxacin (CIP): 5 μg, (4) kanamycin (K), 30 μg, (5) erythromycin (E): 15 μg, (6) chloramphenicol (C): 30 μg, (7) vancomycin: 30 μg, and (8) penicillin (P): 10 μg.…”

“…Subsequent studies, including reviews, investigated the contribution of cemeteries to inorganic and microbial pollution ( Spongberg and Becks, 2000 ; Żychowski, 2012 ; Żychowski and Bryndal, 2015 ; Vaezihir and Mohammadi, 2016 ; Van Allemann et al, 2019 ; Silva et al, 2020 ). Recently, an increasing body of evidence has reported the occurrence of pharmaceuticals, antibiotic resistant bacteria and their resistance genes in environmental media from cemeteries ( Carstens, 2012 ; Carstens et al, 2014 ; Fiedler et al, 2018 ; Abia et al, 2018 , Abia et al, 2019 ). However, comprehensive reviews on antibiotic resistance in the funeral industry, including thanatopraxy care and cemeteries are still lacking.…”