Lady Asantewah Boamah Adomako

Antimicrobial resistance in the environment is a major public health threat, particularly in low- and middle-income countries where there is inadequate wastewater treatment infrastructure. Third generation cephalosporin resistant Escherichia coli (3GCR E. coli) are of particular concern as they have clinical significance and may spread associated resistance genes in environment. This study quantified 3GCR E. coli in wastewater discharged into the Korle Lagoon in Accra, Ghana, and assessed the influence of these discharges on the lagoon. In a cross-sectional study conducted from November 2023 to October 2024, wastewater and lagoon water samples were collected monthly from four discharge points (the Korle Bu Teaching Hospital (KBTH) mortuary drain, the Korle Bu wastewater pumping station, the Mudor Wastewater Treatment Plant and the Lavender Hill Faecal Treatment Plant) and from paired upstream and downstream lagoon sites at each point. Isolates were enumerated by membrane filtration on a selective chromogenic medium, confirmed by MALDI-TOF mass spectrometry, and tested for antimicrobial susceptibility in accordance with CLSI (2024) guidelines. Counts were highest in overflow wastewater from the Korle Bu pumping station (median 3.75 × 10⁶ CFU/100 mL) and in Mudor effluent (1.24 × 10⁶ CFU/100 mL) and differed significantly across sampling sites (Kruskal-Wallis H = 19.6, p = 0.003). Paired comparisons consistently showed higher counts downstream than upstream of the discharge points, most markedly at the KBTH mortuary drain (4.03 × 10⁵ versus 2.36 × 10⁵ CFU/100 mL; p = 0.018) and the Korle Bu pumping station overflow (p = 0.012). The elevated downstream burden indicates active dissemination of resistant 3GCR E. coli along the lagoon continuum. These findings underscore the urgent need to upgrade wastewater treatment infrastructure and to integrate AMR surveillance within wastewater systems in Ghana.

Introduction: The Council for Scientific and Industrial Research (CSIR)-Water Research Institute (WRI) Microbiology Laboratory plays a key national role in water quality testing and serves as Ghana’s focal laboratory for environmental antimicrobial resistance (AMR) surveillance. As part of an ongoing quality system strengthening efforts toward ISO 17025 accreditation, an internal assessment of equipment management practices was conducted with the aim of identifying strengths and areas for improvement to support sustainable laboratory excellence and accreditation readiness. Methods: This was a descriptive cross-sectional assessment using a mixed-methods approach. Existing equipment inventories, calibration certificates, and maintenance records were reviewed. In addition, the WHO Strengthening Laboratory Quality Improvement Process Toward Accreditation (SLIPTA) checklist and ISO 17025 Clause 6.4 were applied as benchmarks against current practices at WRI. Results: A total of 108 equipment was documented across the Microbiology (63) and Molecular Biology (42) sections. There were functional systems for equipment inventory and calibration of key instruments. The SLIPTA score for equipment management was 20/38. Areas identified for enhancement included improved documentation of calibration traceability and structured preventive maintenance planning. An ISO-aligned equipment inventory and maintenance templates were developed to strengthen recordkeeping and support standardization. Conclusion: The CSIR-WRI Microbiology Laboratory has a functional quality assurance system that conforms to the requirements of ISO 17025 standard. The development of equipment inventory and maintenance templates will improve documentation consistency, preventive maintenance, and calibration management. Through this initiative, the laboratory will continue to demonstrate leadership and commitment to quality, reliability, and public health excellence in Ghana.

Antimicrobial resistance (AMR) surveillance plays a critical role in tracking emerging trends and informing evidence-based policies. This study assessed bacterial contamination and resistance profiles of Escherichia coli and Pseudomonas aeruginosa in 1886 drinking water samples from 12 regions of Ghana between April 2024 and April 2025. Findings were compared to a baseline study from the Greater Accra region (2022). Water samples analysed included sachet, bottled, tap, borehole, well, and surface water. Isolates were tested for antibiotic susceptibility using the Kirby–Bauer disk diffusion method. The majority of treated and packaged water samples were free from bacterial contamination. E. coli was frequently detected in untreated surface water (68%) and well water (63%). E. coli isolates from untreated water samples exhibited high resistance to cefuroxime (74%) and amoxicillin-clavulanate (50%); resistance to gentamicin increased from 3% in 2022 to 35% in 2025, while ertapenem resistance rose from 6% to 18%. Multidrug-resistant (MDR) E. coli isolates were found in samples from eight regions, and MDR P. aeruginosa in three, mostly from borehole water. These findings highlight the urgency to integrate AMR surveillance into national water quality initiatives, along with coordinated public health interventions, to educate communities on household water treatment practices and the health risks posed by AMR.

Wastewater treatment plants are efficient in reducing bacterial loads but are also considered potential drivers of environmental antimicrobial resistance (AMR). In this study, we determined the effect of increased influent wastewater volume (from 40% to 66%) in the Legon sewage treatment plant (STP) on the removal of E. coli from sewage, along with changes in AMR profiles. This before and after study compared E. coli loads and AMR patterns in influent and effluent samples from a published baseline study (January–June 2018) with a follow-up study (March–May 2023). Extended-spectrum beta-lactamase (ESBL) E. coli were measured pre- and post-sewage treatment during the follow-up study. The follow-up study showed 7.4% and 24% ESBL E. coli proportions in influent and effluent, respectively. In both studies, the STP was 99% efficient in reducing E. coli loads in effluents, with no significant difference (p = 0.42) between the two periods. More E. coli resistance to antimicrobials was seen in effluents in the follow-up study versus the baseline study. The increased influent capacity did not reduce the efficiency of the STP in removing E. coli from influent wastewater but was associated with increased AMR patterns in effluent water. Further studies are required to determine whether these changes have significant effects on human health.

Introduction: Safety of the environment in which vegetables are grown, marketed and consumed is paramount as most are eaten raw. Irrigation sources include open drains and streams, which are often contaminated with human and animal waste due to poor sanitation infrastructure. In irrigated vegetable farms using such sources in Ghana, we assessed Escherichia coli counts, antibiotic resistance patterns and resistant genes on irrigated lettuce. Methods: A cross-sectional study was conducted between January–May 2022, involving five major vegetable farms in Ghana. Results: Escherichia coli was found in all 25 composite lettuce samples analyzed. Counts expressed in CFU/g ranged from 186 to 3000, with the highest counts found in lettuce irrigated from open drains (1670) and tap water using hose pipes (3000). Among all bacterial isolates, resistance ranged between 49% and 70% for the Watch group of antibiotics, 59% for the Reserved group and 82% were multidrug-resistant. Of 125 isolates, 60 (48%) were extended-spectrum beta-lactamase-producing, of which five (8%) had the bla_TEM-resistant gene. Conclusions: Lettuce was contaminated with Escherichia coli with high levels of antibiotic resistance. We call on the Ghana Ministry of Food and Agriculture, Food and Drugs Authority and other stakeholders to support farmers to implement measures for improving vegetable safety.

With safely managed water accessible to only 19% of the population in Ghana, the majority of its residents are at risk of drinking contaminated water. Furthermore, this water could be a potential vehicle for the transmission of antimicrobial-resistant bacteria. This study assessed the presence of bacteria and the antibiotic resistance profile of Escherichia coli and Pseudomonas aeruginosa in drinking-water sources using membrane filtration and Kirby–Bauer disc diffusion methods. A total of 524 water samples were analyzed for total coliforms, total heterotrophic bacteria, E. coli and P. aeruginosa. Samples included sachets, bottled water, tap water, borehole and well water. Most of the sachet and bottled water samples were within the limits of Ghana’s standards for safe drinking water for the parameters tested. Over 50% of tap and borehole water was also free of E. coli and P. aeruginosa. Overall, of 115 E. coli isolates from tap and ground water samples, most were resistant to cefuroxime (88.7%), trimethoprim–sulfamethoxazole (62.6%) and amoxicillin–clavulanate (52.2%). P. aeruginosa isolates were most resistant to aztreonam (48%). Multidrug resistance was predominantly seen among E. coli isolates (58%). Evidence from this study calls for routine antimicrobial resistance surveillance in drinking water across the country and additional treatment of water sources at household levels.

Most presentations of conjunctivitis are acute. Studies show that uncomplicated cases resolve within 14 days without medication. However, antibiotic prescription remains standard practice. With antimicrobial resistance becoming a public health concern, we undertook this study to assess antibiotic prescription patterns in managing acute conjunctivitis in an eye hospital in Ghana. We recorded 3708 conjunctivitis cases; 201 were entered as acute conjunctivitis in the electronic medical records (January to December 2021). Of these, 44% were males, 56% were females, 39% were under 5 years, 21% were children and adolescents (5–17 years) and 40% were adults (≥18 years). A total of 111 (55.2%) patients received antibiotics, of which 71.2% were appropriately prescribed. The use of antibiotics was more frequent in children under 17 years compared to adults (p < 0.0001). Of the prescribed antibiotics, 44% belonged to the AWaRe “Access” category (Gentamycin, Tetracycline ointment), while 56% received antibiotics in the “Watch” category (Ciprofloxacin, Tobramycin). Although most of the antibiotic prescribing were appropriate, the preponderance of use of the Watch category warrants stewardship to encompass topical antibiotics. The rational use of topical antibiotics in managing acute conjunctivitis will help prevent antimicrobial resistance, ensure effective health care delivery, and contain costs for patients and the health system.

Infections by Extended-Spectrum Beta-Lactamase producing Escherichia coli (ESBL-Ec) are on the increase in Ghana, but the level of environmental contamination with this organism, which may contribute to growing Antimicrobial Resistance (AMR), is unknown. Using the WHO OneHealth Tricycle Protocol, we investigated the contamination of E. coli (Ec) and ESBL-Ec in two rivers in Ghana (Odaw in Accra and Okurudu in Kasoa) that receive effluents from human and animal wastewater hotspots over a 12-month period. Concentrations of Ec, ESBL-Ec and percent ESBL-Ec/Ec were determined per 100 mL sample. Of 96 samples, 94 (98%) were positive for ESBL-Ec. concentrations per 100 mL (MCs100) of ESBL-Ec and %ESBL-Ec from both rivers were 4.2 × 10⁴ (IQR, 3.1 × 10³–2.3 × 10⁵) and 2.79 (IQR, 0.96–6.03), respectively. MCs100 were significantly lower in upstream waters: 1.8 × 10⁴ (IQR, 9.0 × 10³–3.9 × 10⁴) as compared to downstream waters: 1.9 × 10⁶ (IQR, 3.7 × 10⁵–5.4 × 10⁶). Both human and animal wastewater effluents contributed to the increased contamination downstream. This study revealed high levels of ESBL-Ec in rivers flowing through two cities in Ghana. There is a need to manage the sources of contamination as they may contribute to the acquisition and spread of ESBL-Ec in humans and animals, thereby contributing to AMR.

Wastewater treatment plants receive sewage containing high concentrations of bacteria and antibiotics. We assessed bacterial counts and their antibiotic resistance patterns in water from (a) influents and effluents of the Legon sewage treatment plant (STP) in Accra, Ghana and (b) upstream, outfall, and downstream in the recipient Onyasia stream. We conducted a cross-sectional study of quality-controlled water testing (January–June 2018). In STP effluents, mean bacterial counts (colony-forming units/100 mL) had reduced E. coli (99.9% reduction; 102,266,667 to 710), A. hydrophila (98.8%; 376,333 to 9603), and P. aeruginosa (99.5%; 5,666,667 to 1550). Antibiotic resistance was significantly reduced for tetracycline, ciprofloxacin, cefuroxime, and ceftazidime and increased for gentamicin, amoxicillin/clavulanate, and imipenem. The highest levels were for amoxicillin/clavulanate (50–97%) and aztreonam (33%). Bacterial counts increased by 98.8% downstream compared to the sewage outfall and were predominated by E. coli, implying intense fecal contamination from other sources. There was a progressive increase in antibiotic resistance from upstream, to outfall, to downstream. The highest resistance was for amoxicillin/clavulanate (80–83%), cefuroxime (47–73%), aztreonam (53%), and ciprofloxacin (40%). The STP is efficient in reducing bacterial counts and thus reducing environmental contamination. The recipient stream is contaminated with antibiotic-resistant bacteria listed as critically important for human use, which needs addressing.