Multidrug-Resistant Bacteria in Hospital Wastewater of the Korle Bu Teaching Hospital in Accra, Ghana

Prevalence and multidrug resistance patterns of bacterial pathogens in wastewater and drinking water systems from hospital and non-hospital environments in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Wastewater systems worldwide can transport bacterial pathogens alongside antimicrobial resistance genes and pharmaceutical residues. The presence of these pathogens and resistance genes in wastewater systems poses significant public health risks, especially in regions like Ethiopia, where limited wastewater treatment and sanitation infrastructure exist. The spread of infectious diseases and the exacerbation of antimicrobial resistance through wastewater can contribute to the growing global health challenge, with specific implications for local healthcare systems.

OBJECTIVE

This systematic review and meta-analysis aimed to assess the prevalence of bacterial pathogens and their multidrug resistance patterns within wastewater and drinking water systems in Ethiopia, focusing on both hospital and non-hospital environments.

METHODS

A comprehensive search was conducted across electronic databases and grey literature using relevant terms and phrases. Studies meeting the eligibility criteria were extracted into MS Excel and analyzed using STATA version 17 software. A random-effects model was employed to estimate the pooled prevalence of bacterial pathogens in hospital and non-hospital wastewater. Heterogeneity was evaluated using the Cochrane Q test and I² statistics, with a significance threshold of p < 0.05. Publication bias was assessed using a funnel plot and Egger's test. A sensitivity analysis was also performed to determine the influence of individual studies on the overall effect size. Studies included in the meta-analysis reported the prevalence of bacterial species and their corresponding multidrug resistance phenotypes.

RESULT

Out of 472 studies initially identified, 80 met the eligibility criteria for full-text review. Of these, 17 studies were included in the meta-analysis, comprising a total of 848 wastewater and 325 drinking water samples and 2,961 bacterial strains. The most frequently identified bacterium was Pseudomonas aeruginosa (or related species), with an overall prevalence of 41.25% (95% CI: 10.04-81.46%). The pooled prevalence of bacterial pathogens in hospital and non-hospital wastewater systems in Ethiopia was 70.02% (95% CI: 59.90-80.13%), exhibiting substantial heterogeneity (I² = 99.1%, p < 0.001) and the data provides environmental measurements across different categories: wastewater 82.57% (CI: 72.88-92.25%), drinking water 42.18% (CL:10.33, 88.83%). Additionally, the overall prevalence of multidrug-resistant bacterial strains in wastewater was 65.26% (95% CI: 57.23-75.30%), with high heterogeneity (I² = 98.6%, p < 0.001) across different bacterial species and study settings.

CONCLUSION

This systematic review and meta-analysis reveal high levels of bacterial contamination and multidrug resistance within Ethiopian wastewater systems, with significant variability across studies. The findings highlight the urgent need for enhanced wastewater management and monitoring to tackle these public health issues. Future research should focus on standardizing methodologies and investigating the sources of variability to effectively manage and mitigate the risks associated with wastewater systems.

Prevalence of antibiotic-resistant enterobacteriaceae in domestic wastewater and associated health risks in reuse practices

The use of wastewater for non-potable purposes is an important alternative for addressing water scarcity, especially in developing regions. However, minimizing the risks, particularly those associated with emerging contaminants that may induce resistance among pathogens in wastewater, is crucial. This study assessed the occurrence of antibiotic-resistant bacteria in untreated wastewater used for agricultural purposes and evaluated the quantifiable health risks associated with this practice in Tamale, Ghana. The resistance of some Enterobacteriaceae, such as E. coli, Klebsiella, and Salmonella-Shigella, to four commonly used antibiotics in Ghana was assessed using a conventional microbiological culture approach and the Kirby Bauer disk diffusion method. A Quantitative Microbial Risk Assessment (QMRA) was performed to estimate the health risks associated with two distinct scenarios of wastewater reuse: (1) accidental ingestion of contaminated wastewater and soil, and (2) consumption of vegetables irrigated with wastewater. This approach applied a Monte Carlo simulation based on 10,000 interactions and identified E. coli O157:H7 as the reference pathogen. Among Enterobacteriaceae, Klebsiella pneumoniae, Salmonella-Shigella and E. coli were isolated, in concentrations exceeding the limit recommended by the World Health Organization (103 CFU/100 ml). All the isolated bacteria were resistant to metronidazole (5 μg). Thirty-three per cent of Klebsiella pneumoniae isolates were intermediate/moderately susceptible, and all other bacteria were resistant to amoxicillin (30 μg). All Klebsiella pneumoniae and the majority of Salmonella-Shigella (69.8 %) isolates were resistant to trimethoprim-sulfamethoxazole (25 μg) and tetracycline (30 μg). When assessing health risks, the mean annual probability of infection associated with consuming vegetables irrigated with wastewater varied between 5.14 × 10-2 and 9.79 × 10-1 per person per year. Conversely, for the accidental ingestion scenario, the probability was 1.00 per person per year. In these scenarios, the probability of illness ranged from 1.29 × 10-2 to 2.4 × 10-1 and 2.5 × 10-1 per person per year. The health risks posed by these findings surpass the maximum threshold prescribed by the World Health Organization, thereby emphasizing the need for prompt mitigation strategies.

Multidrug-Resistant Bacteria in Aquaculture Systems in Accra, Ghana

Background

Antibiotic resistance (ABR) poses a critical global health challenge, necessitating its surveillance across both human and animal health sectors. This study evaluated ABR in bacteria harboured in reared inland fishes sold in Accra and the pond water from which they originated.

Method

The study was cross-sectional, involving fishes and water sampled from 80 ponds. The gastrointestinal organs of the fishes were homogenised and cultured for bacteria, as were the water samples. The bacteria were identified using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF-MS). Antimicrobial susceptibility test was done using the Kirby-Bauer method. Multidrug-resistant (MDR) bacteria were selected for further testing. The double disc diffusion method was used to detect extended-spectrum beta-lactamase (ESBL) production in isolates that were resistant to third-generation cephalosporins. Whole genome sequencing was performed on the ESBL-positive isolates using the Illumina Miseq platform.

Results

In total, 39 different bacterial species, with their individual numbers totalling 391, were isolated. The bacteria were predominantly Escherichia coli (17%), Aeromonas veronii (11%), Citrobacter freundii (8%), Bacillus cereus (5%), and Klebsiella pneumoniae (5%). The overall ABR rates were cefotaxime (32%), gentamicin (1%), ciprofloxacin (4%), chloramphenicol (19%), tetracycline (37%), meropenem (0%), and ertapenem (0%). Overall MDR and ESBL bacteria prevalence were 13.6% and 1.3%, respectively. The sequence types of the ESBL isolates were ST4684 (80%, n = 4) and ST2005 (20%, n = 1), and the serotypes were H34:09 (80%, n = 4) and H7 (20%, n = 1); the ABR genes were blaCTX-M-15, fosA7, and qnrS1.

Conclusion

The fishes and the pond water were contaminated with a diverse range of bacteria, mainly Escherichia coli and Aeromonas veronii. The ABR, MDR, and ESBL rates were low to moderate. Moreover, the main sequence type and serotype of the ESBL isolates were ST4684 and H34:09, respectively, and the ABR genes were blaCTX-M-15, fosA7, and qnrS1.

Bacterial isolates from drinking water river sources exhibit multi-drug resistant trait

Freshwater habitat is a natural reservoir for antimicrobial resistance (AMR). AMR poses serious human, animal, and environmental public health threats. This study aimed to evaluate the physicochemical and microbiological quality of five selected rivers (Apitipiti 1, Apitipiti 2, Apitipiti 3, Sogidi, and Aba Apa Akinmorin) in Oyo town, Nigeria, as well as the antibiotic resistance pattern of isolated bacterial species, using conventional methods. Most physicochemical parameters were within WHO and NIS permissible limits. Pearson's correlation matrix indicated that there were significant (p < 0.05) interactions among pH, electrical conductivity, temperature, sulphate and chloride salts, and BOD and COD. A total of thirty-two (32) bacterial species were isolated and identified as: Aeromonas (9), Bacillus (2), Corynebacterium (13), Lactobacillus (1), Pseudomonas (2), Staphylococcus (4), and Streptococcus (1). Of the rivers, Sogidi had the highest microbial load (6.36 log CFU/mL) while Apititipiti 1 had the lowest (5.76 log CFU/mL). With regard to antibiotic sensitivity, 81.8% were multidrug-resistant, with Corynebacterium kutscheri and Aeromonas spp. isolated from Apitipiti 2 and Aba Apa Akinmorin rivers, respectively, exhibiting a relatively high antibiotic resistance of 90.9%. This study reveals that these rivers may be unfit for consumption as multidrug-resistant bacteria of public health risk were associated with them.

Aligning antimicrobial resistance surveillance with schistosomiasis research: an interlinked One Health approach

One Health surveillance involves the analysis of human, animal and environmental samples, recognising their interconnectedness in health systems. Such considerations are crucial to investigate the transmission of many pathogens, including drug-resistant bacteria and parasites. The highest rates of antimicrobial resistance (AMR)-associated deaths are observed in sub-Saharan Africa, where concurrently the waterborne parasitic disease schistosomiasis can be highly endemic in both humans and animals. Although there is growing acknowledgment of significant interactions between bacteria and parasites, knowledge of relationships between schistosomes, microbes and AMR remains inadequate. In addition, newly emergent research has revealed the previously underappreciated roles of animals and the environment in both AMR and schistosomiasis transmission. We consider shared environmental drivers and colonisation linkage in this narrative review, with a focus on extended-spectrum beta-lactamase-mediated resistance among bacteria from the Enterobacteriaceae family, which is exceedingly prevalent and responsible for a high burden of AMR-associated deaths. Then we examine novel findings from Malawi, where the landscapes of AMR and schistosomiasis are rapidly evolving, and make comparisons to other geographic areas with similar co-infection epidemiology. We identify several knowledge gaps that could be addressed in future research, including the need to characterise the impact of intestinal schistosomiasis and freshwater contact on intestinal AMR colonisation, before proposing a rationale for connecting AMR surveillance and schistosomiasis research within a One Health framework.

Hospital Wastes as Potential Sources for Multi-Drug-Resistant ESBL-Producing Bacteria at a Tertiary Hospital in Ethiopia

The hospital environment is increasingly becoming an important reservoir for multi-drug-resistant (MDR) Gram-negative bacteria, posing serious challenges to efforts to combat antimicrobial resistance (AMR). This study aimed to investigate the role of hospital waste as a potential source of MDR ESBL-producing bacteria. Samples were collected from multiple sources within a hospital and its vicinity, including surface swabs, houseflies, and sewage samples. The samples were subsequently processed in a microbiology laboratory to identify potential pathogenic bacteria and confirmed using MALDI-TOF MS. Bacteria were isolated from 87% of samples, with the predominant isolates being E. coli (30.5%), Klebsiella spp. (12.4%), Providencia spp. (12.4%), and Proteus spp. (11.9%). According to the double disc synergy test (DDST) analysis, nearly half (49.2%) of the bacteria were identified as ESBL producers. However, despite exhibiting complete resistance to beta-lactam antibiotics, 11.8% of them did not test positive for ESBL production. The characterization of E. coli revealed that 30.6% and 5.6% of them carried blaCTX-M group 1 type-15 and blaNDM genes, respectively. This finding emphasizes the importance of proper hospital sanitation and waste management practices to mitigate the spread of AMR within the healthcare setting and safeguard the health of both patients and the wider community.

Meta-analysis addressing the characterization of antibiotic resistome in global hospital wastewater

Hospital wastewater (HWW) is a significant environmental reservoir of antibiotic resistance genes (ARGs). However, currently, no comprehensive understanding exists of the antibiotic resistome in global HWW. In this study, we attempted to address this knowledge gap through an in silico reanalysis of publicly accessible global HWW metagenomic data. We reanalyzed ARGs in 338 HWW samples from 13 countries in Africa, Asia, and Europe. In total, 2420 ARG subtypes belonging to 30 ARG types were detected, dominated by multidrug, beta-lactam, and aminoglycoside resistance genes. ARG composition in Europe differed from that in Asia and Africa. Notably, the ARGs presented co-occurrence with mobile genetic elements (MGEs), metal resistance genes (MRGs), and human bacterial pathogens (HBP), indicating a potential dissemination risk of ARGs in the HWW. Multidrug resistance genes presented co-occurrence with MGEs, MRGs, and HBP, is particularly pronounced. The abundance of contigs that contained ARG, contigs that contained ARG and HBP, contigs that contained ARG and MGE, contigs that contained ARG and MRG were used for health and transmission risk assessment of antibiotic resistome and screened out 40 high risk ARGs in the global HWW. This study first provides a comprehensive characterization and risk of the antibiotic resistome in global HWW.

Wastewater from healthcare centers in Burkina Faso is a source of ESBL, AmpC-β-lactamase and carbapenemase-producing Escherichia coli and Klebsiella pneumoniae

BACKGROUND

Extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC-β-lactamase and carbapenemase-producing Escherichia coli and Klebsiella pneumoniae have spread into the environment worldwide posing a potential public health threat. However, the prevalence data for low- and middle-income countries are still scarce. The aim of this study was to evaluate the presence of ESBL, AmpC-β-lactamase and carbapenemase-producing and multidrug-resistant E. coli and K. pneumoniae in wastewaters from healthcare centers in Burkina Faso.

RESULTS

Eighty-four (84) wastewater samples were collected from five healthcare centers and plated on selective ESBL ChromAgar. E. coli and Klebsiella pneumoniae isolates were identified using API20E. ESBL-producing bacteria were detected in 97.6% of the samples and their average concentration per hospital ranged from 1.10 × 105 to 5.23 × 106 CFU/mL. Out of 170 putative ESBL-producing isolates (64% of them were E. coli) and 51 putative AmpC-β-lactamase-producing isolates, 95% and 45% were confirmed, respectively. Carbapenemase production was detected in 10 isolates, of which 6 were NDM producers, 3 were OXA-48 producers and 1 was NDM and OXA-48 producer. All isolates were multidrug resistant and, moreover, all of them were resistant to all tested β-lactams. Resistance to ESBL inhibitors was also common, up to 66% in E. coli and 62% in K. pneumoniae. Amikacin, fosfomycin and nitrofurantoin were the antibiotics to which the least resistance was detected.

CONCLUSIONS

This study showed that wastewater from healthcare centers constitutes a reservoir of multidrug-resistant bacteria in Burkina Faso, including carbapenemase producers. Untreated healthcare wastewater entering the environment exposes people and animals to infections caused by these multi-resistant bacteria, which are difficult to treat, especially in the resource-poor settings.

Wastewater treatment plants, an "escape gate" for ESCAPE pathogens

Antibiotics are an essential tool of modern medicine, contributing to significantly decreasing mortality and morbidity rates from infectious diseases. However, persistent misuse of these drugs has accelerated the evolution of antibiotic resistance, negatively impacting clinical practice. The environment contributes to both the evolution and transmission of resistance. From all anthropically polluted aquatic environments, wastewater treatment plants (WWTPs) are probably the main reservoirs of resistant pathogens. They should be regarded as critical control points for preventing or reducing the release of antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic-resistance genes (ARGs) into the natural environment. This review focuses on the fate of the pathogens Enterococcus faecium, Staphylococcus aureus, Clostridium difficile, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae spp. (ESCAPE) in WWTPs. All ESCAPE pathogen species, including high-risk clones and resistance determinants to last-resort antibiotics such as carbapenems, colistin, and multi-drug resistance platforms, were detected in wastewater. The whole genome sequencing studies demonstrate the clonal relationships and dissemination of Gram-negative ESCAPE species into the wastewater via hospital effluents and the enrichment of virulence and resistance determinants of S. aureus and enterococci in WWTPs. Therefore, the efficiency of different wastewater treatment processes regarding the removal of clinically relevant ARB species and ARGs, as well as the influence of water quality factors on their performance, should be explored and monitored, along with the development of more effective treatments and appropriate indicators (ESCAPE bacteria and/or ARGs). This knowledge will allow the development of quality standards for point sources and effluents to consolidate the WWTP barrier role against the environmental and public health AR threats.

In vitro antimicrobial activity of crude propolis extracts and fractions

The search for antimicrobials in propolis presents a new dimension for addressing the problem of antimicrobial drug resistance. The aim of this study was to determine the antimicrobial activity of extracts of crude propolis collected from different regions in Ghana and their active fractions. The antimicrobial activity of the extracts, as well as that of the chloroform, ethyl acetate, and petroleum ether fractions of the active samples were determined using the agar well diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the most active fractions were determined. The various crude propolis extracts frequently produced zones of inhibition against Staphylococcus aureus (17/20) than Pseudomonas aeruginosa (16/20), and Escherichia coli (1/20) test isolates. Chloroform and ethyl acetate solvents produced fractions possessing greater antimicrobial activity than the petroleum ether fraction. The mean MIC range of the most active fractions was greatest for S. aureus (76.0 ± 34.8-48.0 ± 33.0 mg/ml) than for P. aeruginosa (40.8 ± 33.3-30.4 ± 6.7 mg/ml) and E. coli, as was the mean MBC. Propolis has antimicrobial potential, and hence should be exploited as an alternative for the treatment of bacterial infections.