Abstract
This is a systematic review and meta-analysis that evaluated the prevalence of Escherichia coli antibiotic-resistant genes (ARGs) in animals, humans, and the environment in South Africa. This study followed Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to search and use literature published between 1 January 2000 to 12 December 2021, on the prevalence of South African E. coli isolates' ARGs. Articles were downloaded from African Journals Online, PubMed, ScienceDirect, Scopus, and Google Scholar search engines. A random effects meta-analysis was used to estimate the antibiotic-resistant genes of E. coli in animals, humans, and the environment. Out of 10764 published articles, only 23 studies met the inclusion criteria. The obtained results indicated that the pooled prevalence estimates (PPE) of E. coli ARGs was 36.3%, 34.4%, 32.9%, and 28.8% for blaTEM-M-1, ampC, tetA, and blaTEM, respectively. Eight ARGs (blaCTX-M, blaCTX-M-1, blaTEM, tetA, tetB, sul1, sulII, and aadA) were detected in humans, animals and the environmental samples. Human E. coli isolate samples harboured 38% of the ARGs. Analyzed data from this study highlights the occurrence of ARGs in E. coli isolates from animals, humans, and environmental samples in South Africa. Therefore, there is a necessity to develop a comprehensive “One Health” strategy to assess antibiotics use in order to understand the causes and dynamics of antibiotic resistance development, as such information will enable the formulation of intervention strategies to stop the spread of ARGs in the future.
Keywords: Escherichia coli, antibiotic resistance genes, One Health, South Africa
1. Introduction
Escherichia coli is an enteric bacterium that lives in the intestinal tracts of humans and warm-blooded animals as part of commensal variations [1]. Animals are important reservoirs for pathogenic E. coli O157:H7 strains, and majority of the illnesses in humans are linked to undercooked meat, contaminated meat, water or raw milk consumption containing these pathogenic strains [2]. There are different pathotypes of E. coli that are related to the pathogenicity potential based on the presence of colonization factors or production of toxins that cause a variety of diseases [3], of which the majority are difficult to treat [4]. Majority of these strains have been isolated in humans and animals [5], however, water sources are regarded as a major public health risk [6],[7]. In response to bacteria gaining resistance to commonly used antimicrobial drugs, the expression of antibiotic resistance genes (ARGs) in bacteria is becoming a significant issue for public health [8].
Antibiotic resistant bacteria and their resistance genes have emerged as a critical and growing problem in modern medicine [9]. Additionally, it is a growing global public health concern for both animals and humans [10]. Antimicrobials used in human medicine are also utilized in livestock for growth promotion, disease prevention and disease treatment, thereby increasing selection pressures on bacterial pathogens, as well as the risk of antimicrobial resistance (AMR) onset and dissemination [11]. Different antibiotics have been used to treat E. coli infections in animals and humans [12],[13]. Overuse of antibiotics is common in animal husbandry and aquaculture, as they are used as feed additives for disease prevention and growth stimulation [14]. Bacteria develop antibiotic resistance through genetic alterations or the acquisition of ARGs from the host or environment [15].
Surveillance systems are still not well established in many developing nations due to a lack of financial support for sampling, testing, equipment acquisition, and maintenance. In developed countries, antimicrobial resistance surveillance systems implement whole genome sequencing (WGS) as a genotypic tool to supplement phenotypic antimicrobial susceptibility testing [13].
The spread of bacterial antibiotic resistance and pathogenicity imposes a significant health and economic cost [16]. Different bacterial ARGs can become resistant to various antibiotics [17]. Tetracyclines (tet), sulphonamides (sul), β-lactams (bla), macrolides (erm), aminoglycosides (aac), fluoroquinolone (fca), colistin (mcr) and vancomycin (van) are among the classes of antibiotics to which bacterial pathogens can express resistance genes. Key enteric pathogens, such as Klebsiella spp., Salmonella spp. E. coli, Vibrio cholerae and Shigella spp. have demonstrated unfavorable trends in the development of multi-drug resistance (MDR) in the African region to almost all widely available antibiotics [18]–[20]. Despite the high volume of antibiotics used in South Africa, there is a scarcity of knowledge about the relevant ARGs with regard to humans, animals, and the environment. Therefore, this study was carried out to identify prevalence gaps, analyze, and summarize the pooled prevalence of ARGs from E. coli isolates by carrying out a systematic review and meta-analysis of published studies in South Africa.
2. Materials and methods
2.1. Search strategy
Databases, such as African Journals Online (https://www.ajol.info/index.php/ajol/), PubMed (https://www.ncbi.nlm.nih.gov/pubmed/), ScienceDirect (https://www.sciencedirect.com/), Scopus (https://www.scopus.com/) and Google Scholar (https://scholar.google.com/), were searched for English articles published between January 2000 and December 2021. Relevant articles from each database were imported directly into spreadsheet (Microsoft Excel® 2013). All publications, including antimicrobial resistance genes from E. coli, were searched using the following keywords: Antibiotic resistance AND Antibiotic AND drug resistance AND bacterial resistance AND multi-drug resistance AND antibiotic resistance genes AND Escherichia coli OR E. coli AND Human OR animal [beef OR poultry OR livestock OR cattle OR animal OR cows OR chickens OR pig] AND Environment AND South Africa, with the last search conducted on 18th of December 2021. The articles were screened by their title and abstract, and relevant publications were included in this study.
2.2. Inclusion and exclusion criteria
Studies were included on the basis that they fulfilled the following inclusion criteria; names of authors, location, total number of isolates, availability of the full texts, studies conducted in South Africa, studies that investigated antibiotic resistance genes, and articles published in English only on antibiotic resistance genes in E. coli, conducted from January 2000 to December 2021. Studies were excluded if they were not undertaken in South Africa, were reviews, book chapters, dissertations/thesis and not published in English.
2.3. Data extraction and statistical analysis
To reduce the possibility of bias, one author (TR) extracted the data, and a second author examined and confirmed it. The data was extracted from all eligible studies following the inclusion and exclusion criteria described above.
To assess the relative risk, we included articles reporting the number of antibiotic resistance genes in this meta-analysis. Studies were grouped based on bacterial species (E. coli). All statistical analyses were carried out using Comprehensive Meta-analysis (CMA) Version 3.0 by Biostat (Englewood, NJ, USA). The 95% confidence interval (CI) and pooled prevalence estimates (PPE) were calculated. The data generated was visualized using forest plots. The Cochrane Q test was used to calculate Cochran's heterogeneity (Q) among the included studies, as well as the percentage inverse variation (I2). If I2 was ≤ 25%, 50% or ≥ 75%, then heterogeneity was classified as low, moderate or high, respectively. The publication bias was assessed using funnel plots with ocular examination, including the Egger's and Begg's bias indicator tests. A random-effects model was used to generate all pooled estimates. Heterogeneity with a P < 0.05 were considered statistically significant.
3. Results
3.1. Literature search and eligible studies
An electronic search of the databases African Journals Online, PubMed, ScienceDirect, Scopus, and Google Scholar yielded a total of 10764 articles (Figure 1). The search for articles related to studies on antibiotic resistance genes of E. coli in South Africa which were conducted throughout until December 2021. Duplication resulted in the removal of 5211 articles. Then, 5498 were excluded after the screening of titles, abstracts and languages. We evaluated 55 full-text papers for eligibility, and 32 of them did not meet our requirements. The exclusion was based on no reporting of the antibiotic resistance genes (n = 27) and incomplete information on resistance genes (n = 5). Only 23 peer-reviewed journal articles met the inclusion criteria. Table 1 summarizes studies that were included in this review with characteristics, such as province, method of detection, source of samples, number of isolates, and screened ARGs.
Figure 1. PRISMA flowchart showing selection of eligible articles for inclusion in this systematic review and meta-analysis of Escherichia coli antibiotic resistance genes in South Africa.
Table 1. Characteristics of eligible articles consisting of province, method of detection, source of samples, number of isolates and screened ARGs.
| Reference | Province | Method used | Source of samples | One health segment | No. isolates | Antibiotic Resistance Genes |
| [21] | Eastern Cape | PCR | Wastewater treatment | Environment | 223 | strA, aadA, cat I, cmlA1, blaTEM, tetA, tetB, tetC, tetD, tetK, and tetM. |
| [22] | KwaZulu-Natal | m-PCR | Wastewater treatment plant | Environment | 75 | blaCTX-M, blaTEM, blaKPC-2, blaOXA-1, blaNDM-1 |
| [23] | North West | PCR | Humans, cattle, and pigs | Human and animal | 76 | tetB |
| [24] | Gauteng | PCR | Apples, carrots, tomatoes, spinach, and cabbage | Environment | 56 | blaTEM, tetA, tetB, tetL, sulI, sulII, aadA1a, strAB |
| [25] | North West | WGS | Faecal (beef and/or dairy) | Animal | 80 | tetA, tetB |
| [26] | North West | PCR | Stool samples from Human and water | Environment and human | 212 | blaCTX-M, blaDHA, blaSHV |
| [27] | KwaZulu-Natal | PCR | Wastewater treatment plants | Environment | 80 | blaCTX-M, blaTEM, blaSHV |
| [28] | Eastern Cape | PCR | Wastewater treatment plants | Environment | 111 | mcr-1, ermA |
| [29] | Eastern Cape | PCR | Faecal samples from dairy cattle | Animal | 95 | blaampC, blaCMY, blaCTX-M, blaTEM, tetA, strA |
| [30] | Eastern Cape | PCR | Irrigation water and agricultural soil | Environment | 46 | tetA, tetB, tetC, catII, catIII, sulI |
| [31] | Eastern Cape | PCR | Carcasses | Animal | 264 | aadA, strA, ampC, catI, tetB, sul1. |
| [32] | KwaZulu-Natal | PCR | Urinary tract (Human) | Human | 26 | blaCTX-M, gyrA, qnrA, qnrB, qnrS, qepA, aac (6′)-Ib-cr |
| [33] | Gauteng | WGS | Human (blood, urine, and unknown sources) | Human | 20 | blaCTX-M, blaTEM-1B, blaOXA, blaCTX-M-15, blaOXA, blaCTX-M-14, blaCTX-M-27 (E013), blaOXA-10, blaCMY-2 |
| [34] | KwaZulu-Natal | PCR | Chickens (slaughter and final retail product) | Animal | 266 | blaCTX-M, sul1, tetA, tetB |
| [35] | Eastern Cape | PCR | Human (stool) | Human | 265 | sulII, ampC, blaTEM, tetA |
| [36] | North West | PCR | Cattle faeces | Animal | 73 | aadA, strA, strB, ermB, tetA |
| [37] | Eastern Cape | PCR | Stool samples from Human | Human | 324 | ampC, blaTEM, sulI, sulII, aadA, tetA. |
| [38] | Western Cape | PCR | Human | Human | 12 | mcr-1 |
| [39] | Western Cape | PCR | Water from the river | Environment | 171 | aadA, Bla |
| [40] | KwaZulu-Natal | m-PCR | Wastewater treatment plant | Environment | 146 | blaTEM, blaCTX-M |
| [41] | Eastern Cape | PCR | Stool samples from Human | Human | 106 | catA1, tetA |
| [42] | Western Cape | PCR | Humans | Human | 22 | blaCTX-M, blaCTX-M-15, blaCTXM-14, blaCTX-M-3. |
| [43] | Western Cape | PCR | Wildlife and livestock species | Animal | 35 | blaCMY, sul1, sul2, aadA1, tetA, tetB. |
WGS = Whole Genome Sequencing, m-PCR = Multiplex PCR
Of the 23 included studies, 7 were environmental samples, 6 were samples from animal sources, 8 were from human and 1 included both human and environmental samples. All the studies included in this review were derived from five provinces in South Africa. Eastern Cape (n = 8) had majority of the studies, followed by KwaZulu-Natal (n = 5), North West (n = 4), Western Cape (n = 2) and Gauteng (n = 1) with the least number of studies (Table 1). The most common method for determining the antibiotics resistance genes of E. coli isolated from all articles included in this systematic review and meta-analysis was PCR (19/23:82.6%), followed by multiplex PCR (2/23:8.7%) and WGS (2/23:8.7%).
3.2. Pooled prevalence estimates (PPE) of antibiotic resistance genes
The blaTEM-M-1 gene was detected from E. coli isolates with a PPE of 36.3% (95% CI: 18.7–58.5), followed by ampC gene 34.4% (95% CI: 16.6–58.1), tetA 32.9% (95% CI: 17.1–53.7), blaTEM 28.8% (95% CI: 18.8–41.5), blaTEM-M 23.3% (95% CI: 7.6–44.1), blaSHV 22.6% (95% CI: 3.3–71.7), strA 21.7% (95% CI: 4.2–63.3), aad 19.4% (95% CI: 9.1–36.8), sul1 15.8% (95% CI: 5.6–37.4), tetB 14.7% (95% CI: 8.5–24.2), cat1 14.0% (95% CI: 0.1–94.8) and sulII 11.9% (95% CI: 4.1–30.3). The rest of the PPE of ARGs is shown in Table 2. However, genes such as blaOXA-1, cat2, tetD, tetK, tetG, tetM, blaCMY-2, dfrA7, strA, bla pse1, bla ampC, ant (3″)-la, qnr-B, qnr-S, ermB, blaCTX-M, blaCTX-M-15, blaCTX-M-3 and blaSHV-2 were not included for meta-analysis due to the low number of studies. The forest plot depicts the point estimate for individual studies, reporting the presence of ampC, aadA, blaTEM and tetA (Figure S1).
Table 2. Pooled prevalence rate and 95% CI of antibiotic resistance genes of E. coli species based on meta-analysis.
| Antimicrobial agents | Number of studies | Number of isolates | % Prevalence (95% CI) | I2 (95% CI) | Begg and Mazumdar rank P-value |
| strA | 4 | 126 | 21.7 | (4.2–63.3) | 0.49691 |
| cat1 | 3 | 109 | 14.0 | (0.1–94.8) | 0.60151 |
| blaCTX-M | 5 | 85 | 23.3 | (7.6–44.1) | 1.0000 |
| blaSHV | 4 | 201 | 22.6 | (5.6–37.4) | 1.0000 |
| tetB | 7 | 147 | 14.7 | (8.5–24.2) | 0.65230 |
| ampC | 3 | 104 | 34.4 | (16.6–58.1) | 0.60151 |
| sulII | 5 | 87 | 11.9 | (4.1–30.3) | 1.0000 |
| blaCTX-M-1 | 6 | 167 | 36.3 | (18.7–58.5) | 0.85098 |
| blaTEM | 9 | 323 | 28.8 | (18.8–41.5) | 0.53161 |
| tetA | 10 | 401 | 32.9 | (17.1–53.7) | 0.17971 |
| sul1 | 6 | 111 | 15.8 | (5.6–37.4) | 0.57303 |
| aadA | 5 | 172 | 19.4 | (9.1–36.8) | 0.14164 |
A total of 6 animal studies with 813 isolates were included in the meta-analysis, and they had a PPE of 25.4% (95% CI: 13.7–42.3) and 41.2% (95% CI: 10.1–81.4) for the blaTEM and tetA genes, respectively. For humans, 8 studies with 738 isolates were included in this review. The strA gene had a PPE of 30.2% (95% CI: 4.2–81.1), followed by tetA 22.1% (95% CI: 9.1–44.7), Sul1 8.5% (95% CI: 6.5–11.1), Sul11 5.8% (95% CI: 2.9–11.4), and tetB 13.4% (95% CI: 10.9–16.2). While 7 studies from the environment were included in this review, only the blaTEM gene was reported, with a PPE of 45.7% (95% CI: 22.5–70.9) from 685 isolates (Figure 2).
Figure 2. Antibiotic resistance genes detected in South African E. coli isolates from animals, humans, and the environment.
3.3. One health perspective
Of the 23 studies, 29 ARGs from humans, 26 from animals, and 19 from the environment were detected. Eight ARGs were detected in both humans, animals and in the environmental samples, whereas 9 were detected from humans and animals, 3 from animals and the environment and 2 from humans and the environment, as shown in Table 3.
Table 3. The antimicrobial-resistant genes (ARGs) detected between environmental, humans and animals.
| Human & animal | Human & environment | Animal & environment | Animals, human & environment |
| ampC | blaSHV | aadA1a | blaCTX-M |
| strA | blaOXA-1 | aadA1 | blaCTX-M-1 |
| catI | qnrB | ermB | blaTEM |
| catII | tetA | ||
| cmlA1 | tetB | ||
| tetC | sul1 | ||
| tetD | sulII | ||
| tetM | aadA | ||
| qnrB |
3.4. Publication bias
The Begg and Mazumdar rank correlation test demonstrated no significant publishing bias for all parameters.
4. Discussion
Most of the studies included in this review were conducted on humans (34.8%). Out of the nine provinces, only five (55%) provinces, that is, North West, Eastern Cape, KwaZulu-Natal, Gauteng and Western Cape, were represented in this study. However, the Free State, Limpopo, Mpumalanga, and Northern Cape were not represented in the data sets, which may be due to a lack of research facilities in these provinces and/or a scarcity of researchers in the infectious microbiology field. The other reason might be that there are no Medical Research Council (MRC) institutes in those provinces.
AMR continues to increase internationally as a result of the widespread and unchecked use of antibiotics in veterinary and medical procedures [44]. Bacterial antibiotic resistance can spread to unaffected bacteria via DNA or other genetic components like integrons, bacteriophages and transposons [45]. Bacteria expressing ARGs are on the rise as a result of widespread agricultural practices, and the excessive and uncontrolled use of antibiotics to treat human illnesses [45]. Humans, animals, and the environmental components interact, and either directly or indirectly contribute to the spread of antimicrobial resistance [46],[44]. In this study, a high prevalence of ARGs in E. coli was found in both human and animal samples.
Twelve resistance genes, namely streptomycin (strA), chloramphenicol (catI), β-lactams (blaTEM, blaCTX-M, blaCTX-M-1, blaSHV), sulphonamides (sul1 and sulII), aminoglycosides (aadA), ampicillin (ampC) and tetracycline (tetA and tetB) were the most detected resistant genes, based on data obtained from studies analyzed in the current review. Infections brought on by pathogenic E. coli have been successfully treated with β-lactam antibiotics. However, a vast number of hydrolytic enzymes, namely the β-lactamases produced by bacteria, are currently seriously impairing the usefulness of β-lactams [47]. The tet (A, B, and C) gene is amongst detected genes in E. coli in this study from both animals, humans, and the environment. Tetracyclines are the most often used or overused antibiotics in livestock production in South Africa [48],[44]. Furthermore, Eagar et al. [49] indicated that tetracyclines were the most commonly used antibiotics in animals in South Africa between the years 2002 and 2004, hence, it is not surprising that most bacteria have a high level of tetracycline (tet) resistance [45],[50],[51]. Therefore, the excessive continued use of this antibiotic has led to the development of resistance. The chloramphenicol, catI gene, was also detected in humans and animals. This is surprising because chloramphenicol has been removed from standard prescription lists due to the side effect of bone marrow aplasia. Gene cassettes of the aadA have been widely found in the environment and in animal production. The aadA group of genes encodes resistance to streptomycin and spectinomycin [14].
The quinolones, qnr gene, was also found in E. coli isolates of humans, animals and the environment in this study. DNA gyrase and topoisomerase IV are protected from quinolone chemicals by the genes (qnr) expressing proteins that are members of the pentapeptide repeat family, which mediates quinolone resistance in plasmids [52],[53]. According to this study, environmental organisms may have been the source of the circulating qnr genes [54]. Fluoroquinolone resistance is significant since it can spread rapidly among bacterial species that threaten human health. The cross-species and cross-genus transfers of resistance determinants are also possible [55].
In this review, three major molecular approaches were utilized to detect ARGs, such as PCR, multiplex PCR, and whole genome sequencing (WGS). Eighty-eight percent of the articles used traditional PCR techniques, most likely due to easy access to PCR cyclers and the reduced costs involved with PCR. Despite the fact that WGS offers a number of benefits, it was only utilized twice in all of the studies analyzed. More than 70 genes that may be related to drug resistance have been found in many recent large WGS investigations [56]. The WGS analysis has demonstrated the capacity to eliminate phenotypic and genotypic inconsistencies [56]–[58]. Due to its ability to quickly identify resistance pathways, WGS has become a crucial tool for profiling ARGs and has also played a role in measuring the rate at which resistance emerges [56]. WGS and other high-throughput diagnostic technologies have shown significant promise in medical diagnostics, and have proven to be essential in the control of antibiotic resistance [59].
Using the “One Health” approach, multiple disciplines work locally, nationally, and internationally to achieve optimal human, animal, and environmental health, realizing that the three are interconnected [60]. Since humans, animals, plants, food, and the environment are the main sources of antimicrobial resistance, the necessity of a “One Health” control strategy is highlighted in combating this problem [15]. The presence of similar zoonotic E. coli isolates, in animals, humans and the environment must be taken into consideration in South Africa. Food safety, zoonotic disease control, laboratory services, neglected tropical diseases, environmental health, and antimicrobial resistance are among the areas of work where a “One Health” approach is particularly relevant, according to the World Health Organization (WHO) (https://www.euro.who.int/en/home). The WHO recommends using a “One Health” approach to address health threats at all three interfaces [10],[62]. There is a dynamic interaction between human, animal, and environmental components that contribute to the rapid emergence and spread of antimicrobial resistance, either directly or indirectly [44]. This concept emphasizes the importance of balance and interconnectedness across the human-animal-environment sectors.
Even though we have organized data on the prevalence of antibiotic resistance genes in E. coli, the following limitations apply to our study: PPE of some resistant genes were not calculated because there are few reports on each. With respect to provinces, Limpopo, Free State, Mpumalanga, and Northern Cape are underrepresented.
5. Conclusions
This systematic review and meta-analysis gave an overview of scientific data on E. coli antibiotic resistance genes in human, animal, and environmental samples from South Africa. There are significant gaps in surveillance and a lack of published studies on the prevalence of E. coli resistance genes in some provinces like Limpopo, Free State, Mpumalanga, and Northern Cape. This study revealed the highest PPE of E. coli resistance genes to ampC, tetA, blaTEM, blaTEM-M, blaSHV, strA, aad, sul1, tetB and cat1, while eight genes (blaCTX-M, blaCTX-M-1, blaTEM, tetA, tetB, sul1, sulII and aadA) were detected in E. coli isolates from animals, humans, and the environment. This finding calls for the restricted use of this group of antibiotics. There is also a need for detailed studies that document the relationships between the phenotypic and genotypic occurrences of antibiotic resistance, as well as the presence of virulence genes. The fact that resistance genes have been detected in humans, animals, and environmental samples means there is a need for consolidated “One Health” approaches from the ecological, human, and animal health sectors in terms of epidemiological, therapeutics, and policy formulation research.
Footnotes
Conflict of interest: We declare that there are no conflicts of interest.
Author contributions: TR, KEL and OT conceived and designed the study. TR performed the literature review and extraction of data. TR and MT analyzed and interpreted the data, created figures and tables and drafted the manuscript. OT and KEL offered mentorship and guidance on antimicrobial resistance, as well as reviewing the manuscript. All authors read, commented and approved the final manuscript.
References
- 1.Jang J, Hur HG, Sadowsky MJ, et al. Environmental Escherichia coli: ecology and public health implications—a review. J Appl Microbiol. 2017;123:570–581. doi: 10.1111/jam.13468. [DOI] [PubMed] [Google Scholar]
- 2.Meng J, LeJeune JT, Zhao T. Enterohemorrhagic Escherichia coli. In: Doyle M.P., Buchanan R.L., editors. Food Microbiol: Fundamentals and frontiers. 4 Eds. ASM Press; 2012. pp. 287–309. [DOI] [Google Scholar]
- 3.Kaper JB, Nataro JP, Mobley HL. Pathogenic Escherichia coli. Nat Rev Microbiol. 2004;2:123–140. doi: 10.1038/nrmicro818. [DOI] [PubMed] [Google Scholar]
- 4.Sonola VS, Katakweba A, Misinzo G, et al. Molecular epidemiology of antibiotic resistance genes and virulence factors in multidrug-resistant Escherichia coli isolated from rodents, humans, chicken, and household soils in Karatu, Northern Tanzania. Int J Environ Res Public Health. 2022;19:5388. doi: 10.3390/ijerph19095388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Nobili G, Franconieri I, La Bella G, et al. Prevalence of verocytotoxigenic Escherichia coli strains isolated from raw beef in southern Italy. Int J Food Microbiol. 2017;257:201–205. doi: 10.1016/j.ijfoodmicro.2017.06.022. [DOI] [PubMed] [Google Scholar]
- 6.Abd El Shakour EH, Mostafa A. Antimicrobial resistance profiles of Enterobacteriaceae isolated from Rosetta Branch of river Nile, Egypt. World Appl Sci J. 2012;19:1234–1243. doi: 10.5829/idosi.wasj.2012.19.09.2785. [DOI] [Google Scholar]
- 7.Peirano G, van Greune CH, Pitout JD. Characteristics of infections caused by extended-spectrum β-lactamase–producing Escherichia coli from community hospitals in South Africa. Diagn Microbiol Infect Dis. 2011;69:449–453. doi: 10.1016/j.diagmicrobio.2010.11.011. [DOI] [PubMed] [Google Scholar]
- 8.Racewicz P, Majewski M, Biesiada H. Prevalence and characterisation of antimicrobial resistance genes and class 1 and 2 integrons in multiresistant Escherichia coli isolated from poultry production. Sci Rep. 2022;12:1–13. doi: 10.1038/s41598-022-09996-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Munita JM, Arias CA. Mechanisms of antibiotic resistance. Microbiol Spectr. 2016;4:4–2. doi: 10.1128/microbiolspec.VMBF-0016-2015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Esperón F, Sacristán C, Carballo M. Antimicrobial resistance genes in animal manure, manure-amended and nonanthropogenically impacted soils in Spain. Adv Biosci Biotechnol. 2018;9:469–480. doi: 10.4236/abb.2018.99032. [DOI] [Google Scholar]
- 11.Muloi DM, Wee BA, McClean DM, et al. Population genomics of Escherichia coli in livestock-keeping households across a rapidly developing urban landscape. Nat Microbiol. 2022;7:581–589. doi: 10.1038/s41564-022-01079-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Chen X, Zhou L, Tian K, et al. Metabolic engineering of Escherichia coli: a sustainable industrial platform for bio-based chemical production. Biotechnol Adv. 2013;31:1200–1223. doi: 10.1016/j.biotechadv.2013.02.009. [DOI] [PubMed] [Google Scholar]
- 13.Manishimwe R, Moncada PM, Bugarel M, et al. Antibiotic resistance among Escherichia coli and Salmonella isolated from dairy cattle feces in Texas. Plos One. 2021;16:p.e0242390. doi: 10.1371/journal.pone.0242390. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Su HC, Ying GG, Tao R, et al. Occurrence of antibiotic resistance and characterization of resistance genes and integrons in Enterobacteriaceae isolated from integrated fish farms in south China. J Environ Monit. 2011;13:3229–3236. doi: 10.1039/c1em10634a. [DOI] [PubMed] [Google Scholar]
- 15.Amarasiri M, Sano D, Suzuki S. Understanding human health risks caused by antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in water environments: Current knowledge and questions to be answered. Crit Rev Environ Sci Technol. 2020;50:2016–2059. doi: 10.1080/10643389.2019.1692611. [DOI] [Google Scholar]
- 16.Tao S, Chen HLN, Wang T, et al. The spread of antibiotic resistance genes in vivo model. Can J Infect Dis Med Microbiol. 2022;2022 doi: 10.1155/2022/3348695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Jian Z, Zeng L, Xu T. Antibiotic resistance genes in bacteria: Occurrence, spread, and control. J Basic Microbiol. 2021;61:1049–1070. doi: 10.1002/jobm.202100201. [DOI] [PubMed] [Google Scholar]
- 18.Nys S, Okeke IN, Kariuki S. Antibiotic resistance of faecal Escherichia coli from healthy volunteers from eight developing countries. J Antimicrob Chemother. 2004;54:952–955. doi: 10.1093/jac/dkh448. [DOI] [PubMed] [Google Scholar]
- 19.Ekwanzala MD, Dewar JB, Kamika I. Systematic review in South Africa reveals antibiotic resistance genes shared between clinical and environmental settings. Infect Drug Resist. 2018;11:1907. doi: 10.2147/IDR.S170715. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Ramatla TA, Mphuthi N, Ramaili T. Molecular detection of zoonotic pathogens causing gastroenteritis in humans: Salmonella spp., Shigella spp. and Escherichia coli isolated from Rattus species inhabiting chicken farms in North West Province, South Africa. J S Afr Vet Assoc. 2022;93:1–7. doi: 10.36303/JSAVA.83. [DOI] [PubMed] [Google Scholar]
- 21.Adefisoye MA, Okoh AI. Identification and antimicrobial resistance prevalence of pathogenic Escherichia coli strains from treated wastewater effluents in Eastern Cape, South Africa. Microbiologyopen. 2016;5:143–151. doi: 10.1002/mbo3.319. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Adegoke AA, Madu CE, Aiyegoro OA. Antibiogram and beta-lactamase genes among cefotaxime resistant E. coli from wastewater treatment plant. Antimicrob Resist Infect Control. 2020;9:1–12. doi: 10.1186/s13756-020-0702-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Ateba CN, Bezuidenhout CC. Characterisation of Escherichia coli O157 strains from humans, cattle and pigs in the North-West Province, South Africa. Int J Food Microbiol. 2008;128:181–188. doi: 10.1016/j.ijfoodmicro.2008.08.011. [DOI] [PubMed] [Google Scholar]
- 24.Baloyi T, Duvenage S, Du Plessis E, et al. Multidrug resistant Escherichia coli from fresh produce sold by street vendors in South African informal settlements. Int J Environ Health Res. 2022;32:1513–1528. doi: 10.1080/09603123.2021.1896681. [DOI] [PubMed] [Google Scholar]
- 25.Bumunang EW, McAllister TA, Zaheer R. Characterization of non-O157 Escherichia coli from cattle faecal samples in the North-West Province of South Africa. Microorganisms. 2019;7:272. doi: 10.3390/microorganisms7080272. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Chukwu MO, Abia ALK, Ubomba-Jaswa E. Antibiotic resistance profile and clonality of E. coli isolated from water and paediatric stool samples in the North West province South Africa. J Pure Appl Microbiol. 2019;13:517–530. doi: 10.22207/JPAM.13.1.58. [DOI] [Google Scholar]
- 27.Gumede SN, Abia AL, Amoako DG. Analysis of wastewater reveals the spread of diverse Extended-Spectrum β-Lactamase-Producing E. coli strains in uMgungundlovu District, South Africa. Antibiotics. 2021;10:860. doi: 10.3390/antibiotics10070860. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Igwaran A, Iweriebor BC, Okoh AI. Molecular characterization and antimicrobial resistance pattern of Escherichia coli recovered from wastewater treatment plants in Eastern Cape South Africa. Int J Environ Res Public health. 2018;15:1237. doi: 10.3390/ijerph15061237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Iweriebor BC, Iwu CJ, Obi LC. Multiple antibiotic resistances among Shiga toxin producing Escherichia coli O157 in feces of dairy cattle farms in Eastern Cape of South Africa. BMC Microbiol. 2015;5:1–9. doi: 10.1186/s12866-015-0553-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Iwu CD, du Plessis E, Korsten L. Antibiogram imprints of E. coli O157: H7 recovered from irrigation water and agricultural soil samples collected from two district municipalities in South Africa. Int J Environ Stud. 2021;78:940–953. doi: 10.1080/00207233.2020.1854522. [DOI] [Google Scholar]
- 31.Jaja IF, Oguttu J, Jaja CJI. Prevalence and distribution of antimicrobial resistance determinants of Escherichia coli isolates obtained from meat in South Africa. Plos One. 2020;15:e0216914. doi: 10.1371/journal.pone.0216914. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Kubone PZ, Mlisana KP, Govinden U. Antibiotic susceptibility and molecular characterization of uropathogenic Escherichia coli associated with community-acquired urinary tract infections in urban and rural settings in South Africa. Trop Med Infect Dis. 2020;5:176. doi: 10.3390/tropicalmed5040176. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Mbelle NM, Feldman C, Osei Sekyere J. The resistome, mobilome, virulome and phylogenomics of multidrug-resistant Escherichia coli clinical isolates from Pretoria, South Africa. Sci Rep. 2019;9:1–16. doi: 10.1038/s41598-019-52859-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34.McIver KS, Amoako DG, Abia ALK. Molecular epidemiology of antibiotic-resistant Escherichia coli from farm-to-fork in intensive poultry production in KwaZulu-Natal, South Africa. Antibiotics. 2020;9:850. doi: 10.3390/antibiotics9120850. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Mkuhlu NA, Chuks IB, Chikwelu OL. Characterization and antibiotic susceptibility profiles of pathogenic Escherichia coli isolated from diarrhea samples within the Buffalo city metropolitan municipality, eastern Cape, South Africa. Open Microbiol J. 2020;14:321–330. doi: 10.2174/1874434602014010321. [DOI] [Google Scholar]
- 36.Montso PK, Mlambo V, Ateba CN. The first isolation and molecular characterization of Shiga Toxin-producing virulent multi-drug resistant atypical enteropathogenic Escherichia coli O177 serogroup from South African Cattle. Front Cell Infect Microbiol. 2019;9:333. doi: 10.3389/fcimb.2019.00333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Msolo L, Iweriebor BC, Okoh AI. Antimicrobial resistance profiles of diarrheagenic E. coli (DEC) and Salmonella species recovered from diarrheal patients in selected rural communities of the amathole district municipality, Eastern Cape Province, South Africa. Infect Drug Resist. 2020;13:4615. doi: 10.2147/IDR.S269219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Newton-Foot M, Snyman Y, Maloba MRB. Plasmid-mediated mcr-1 colistin resistance in Escherichia coli and Klebsiella spp. clinical isolates from the Western Cape region of South Africa. Antimicrob Resist Infect Control. 2017;6:1–7. doi: 10.1186/s13756-017-0234-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39.Nontongana N, Sibanda T, Ngwenya E. Prevalence and antibiogram profiling of Escherichia coli pathotypes isolated from the Kat River and the Fort Beaufort abstraction water. Int J Environ Res Public Health. 2014;11:8213–8227. doi: 10.3390/ijerph110808213. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Nzima B, Adegoke AA, Ofon UA. Resistotyping and extended-spectrum beta-lactamase genes among Escherichia coli from wastewater treatment plants and recipient surface water for reuse in South Africa. New Microbes New Infect. 2020;38:100803. doi: 10.1016/j.nmni.2020.100803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Omolajaiye SA, Afolabi KO, Iweriebor BC. Pathotyping and antibiotic resistance profiling of Escherichia coli isolates from children with acute diarrhea in amatole district municipality of Eastern Cape, South Africa. BioMed Res Int. 2020;2020 doi: 10.1155/2020/4250165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Peirano G, van Greune CH, Pitout JD. Characteristics of infections caused by extended-spectrum β-lactamase–producing Escherichia coli from community hospitals in South Africa. Diagn Microbiol Infect Dis. 2011;69:449–453. doi: 10.1016/j.diagmicrobio.2010.11.011. [DOI] [PubMed] [Google Scholar]
- 43.van den Honert MS, Gouws PA, Hoffman LC. Escherichia coli Antibiotic Resistance Patterns from Co-Grazing and Non-Co-Grazing Livestock and Wildlife Species from Two Farms in the Western Cape, South Africa. Antibiotics. 2021;10:618. doi: 10.3390/antibiotics10060618. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Ramatla T, Tawana M, Onyiche TE. Prevalence of antibiotic resistance in Salmonella serotypes concurrently isolated from the environment, animals, and humans in South Africa: a systematic review and meta-analysis. Antibiotics. 2021;10:1435. doi: 10.3390/antibiotics10121435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Onohuean H, Agwu E, Nwodo UU. Systematic review and meta-analysis of environmental Vibrio species–antibiotic resistance. Heliyon. 2022;2022:e08845. doi: 10.1016/j.heliyon.2022.e08845. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Mossoro-Kpinde CD, Manirakiza A, Mbecko JR. Antimicrobial resistance of enteric Salmonella in Bangui, central African republic. J Trop Med. 2015;2015 doi: 10.1155/2015/483974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 47.Bajaj P, Singh NS, Virdi JS. Escherichia coli β-Lactamases: What Really Matters. Front Microbiol. 2016;7:417. doi: 10.3389/fmicb.2016.00417. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 48.Mokgophi TM, Gcebe N, Fasina F. Antimicrobial resistance profiles of Salmonella isolates on chickens processed and retailed at outlets of the informal market in Gauteng Province, South Africa. Pathogens. 2021;10:273. doi: 10.3390/pathogens10030273. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 49.Eagar H, Swan G, Van Vuuren M. A survey of antimicrobial usage in animals in South Africa with specific reference to food animals. J S Afr Vet Assoc. 2012;83:1–8. doi: 10.4102/jsava.v83i1.16. [DOI] [PubMed] [Google Scholar]
- 50.Gao P, Mao D, Luo Y. Occurrence of sulfonamide and tetracycline-resistant bacteria and resistance genes in aquaculture environment. Water Res. 2012;46:2355–2364. doi: 10.4102/jsava.v83i1.16. [DOI] [PubMed] [Google Scholar]
- 51.Nguyen F, Starosta AL, Arenz S. Tetracycline antibiotics and resistance mechanisms. Biol Chem. 2014;395:559–575. doi: 10.1515/hsz-2013-0292. [DOI] [PubMed] [Google Scholar]
- 52.Rezazadeh M, Baghchesaraei H, Peymani A. Plasmid-mediated quinolone-resistance (qnr) genes in clinical isolates of Escherichia coli collected from several hospitals of Qazvin and Zanjan Provinces, Iran. Osong Public Health Res Perspect. 2016;7:307–312. doi: 10.1016/j.phrp.2016.08.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 53.Taha SA, Omar HH. Characterization of plasmid-mediated qnrA and qnrB genes among Enterobacteriaceae strains: quinolone resistance and ESBL production in Ismailia, Egypt. Egypt J Med Hum Genet. 2019;20:1–7. doi: 10.1186/s43042-019-0026-1. [DOI] [Google Scholar]
- 54.Colomer-Lluch M, Jofre J, Muniesa M. Quinolone resistance genes (qnrA and qnrS) in bacteriophage particles from wastewater samples and the effect of inducing agents on packaged antibiotic resistance genes. J Antimicrob Chemother. 2014;69:1265–1274. doi: 10.1093/jac/dkt528. [DOI] [PubMed] [Google Scholar]
- 55.Tyson GH, Li C, Hsu CH, et al. Diverse fluoroquinolone resistance plasmids from retail meat E. coli in the United States. Front Microbiol. 2019;10:2826. doi: 10.3389/fmicb.2019.02826. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 56.Köser CU, Ellington MJ, Peacock SJ. Whole-genome sequencing to control antimicrobial resistance. Trends Genet. 2014;30:401–407. doi: 10.1016/j.tig.2014.07.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 57.Lekota KE, Bezuidt OKI, Mafofo J. Whole genome sequencing and identification of Bacillus endophyticus and B. anthracis isolated from anthrax outbreaks in South Africa. BMC Microbiol. 2018;18:1–15. doi: 10.1186/s12866-018-1205-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 58.Cooper AL, Low AJ, Koziol AG. Systematic evaluation of whole genome sequence-based predictions of Salmonella serotype and antimicrobial resistance. Front Microbiol. 2020;11:549. doi: 10.3389/fmicb.2020.00549. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 59.Kumburu HH, Sonda T, van Zwetselaar M. Using WGS to identify antibiotic resistance genes and predict antimicrobial resistance phenotypes in MDR Acinetobacter baumannii in Tanzania. J Antimicrob Chemother. 2019;74:1484–1493. doi: 10.1093/jac/dkz055. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 60.Lerner H, Berg C. The concept of health in One Health and some practical implications for research and education: what is One Health? Infect Ecol Epidemiol. 2015;5:25300. doi: 10.3402/iee.v5.25300. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 61.Mackenzie JS, Jeggo M. The One Health approach—Why is it so important? Tropical Med Infect Dis. 2019;4:88. doi: 10.3390/tropicalmed4020088. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 62.Ramatla T, Tawana M, Mphuthi MB, et al. Prevalence and antimicrobial resistance of Campylobacter species in South Africa: A “One Health” approach using systematic review and meta-analysis. Int J Infect Dis. 2022;125:294–304. doi: 10.1016/j.ijid.2022.10.042. [DOI] [PubMed] [Google Scholar]
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