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11 result(s) for "Aworh, Mabel K."
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Household wastewater as a sentinel for community-level antimicrobial resistance: a cross-sectional study in Gombe, Nigeria
Antimicrobial resistance (AMR) represents a critical global health challenge, with projections suggesting 10 million annual deaths by 2050. Environmental transmission routes, particularly through wastewater, remain understudied despite their significant role in resistance development and spread. This study investigated household wastewater as a sentinel for community-level AMR patterns in Gombe, Nigeria. A cross-sectional study was conducted between December 2024 and February 2025, collecting 320 household wastewater samples across seven districts in Gombe using multi-stage sampling techniques. Bacterial isolation followed standard conventional methods. Antibiotic susceptibility testing was performed using the disc diffusion method. Extended-spectrum beta-lactamase (ESBL) production was confirmed using double-disc synergy tests, and PCR detected key resistance genes in selected isolates. Microbiological analysis yielded 402 bacterial isolates, with 81% classified as multidrug-resistant (MDR). MDR prevalence across districts ranged from 60.3% to 95.9% ( p  < 0.01). Gram-negative bacteria predominated, with Escherichia coli (32.7%), Klebsiella pneumoniae (19.2%), and Pseudomonas aeruginosa (11.2%) being the most common. ESBL production was detected in 54% of tested isolates. MDR isolates demonstrated resistance to approximately 8 antibiotics (median), while non-MDR isolates showed resistance to only 1–2 antibiotics. Molecular analysis revealed a high prevalence of clinically significant resistance genes, with blaCTX-M detected in 100% of tested isolates. This study demonstrates household wastewater’s value as a community-level antimicrobial resistance indicator. The high prevalence of MDR bacteria (81%) highlights significant environmental reservoirs that could contribute to community AMR transmission. Wastewater-based epidemiology can serve as a cost-effective complement to traditional clinical surveillance, especially in resource-limited settings.
Cholera outbreak in some communities in North-East Nigeria, 2019: an unmatched case–control study
Background Cholera, a diarrheal disease caused by the bacterium Vibrio cholerae , transmitted through fecal contamination of water or food remains an ever-present risk in many countries, especially where water supply, sanitation, food safety, and hygiene are inadequate. A cholera outbreak was reported in Bauchi State, North-eastern Nigeria. We investigated the outbreak to determine the extent and assess risk factors associated with the outbreak. Methods We conducted a descriptive analysis of suspected cholera cases to determine the fatality rate (CFR), attack rate (AR), and trends/patterns of the outbreak. We also conducted a 1:2 unmatched case–control study to assess risk factors amongst 110 confirmed cases and 220 uninfected individuals (controls). We defined a suspected case as any person > 5 years with acute watery diarrhea with/without vomiting; a confirmed case as any suspected case in which there was laboratory isolation of Vibrio cholerae O1 or O139 from the stool while control was any uninfected individual with close contact (same household) with a confirmed case. Children under 5 were not included in the case definition however, samples from this age group were collected where such symptoms had occurred and line-listed separately. Data were collected with an interviewer-administered questionnaire and analyzed using Epi-info and Microsoft excel for frequencies, proportions, bivariate and multivariate analysis at a 95% confidence interval. Results A total of 9725 cases were line-listed with a CFR of 0.3% in the state. Dass LGA had the highest CFR (14.3%) while Bauchi LGA recorded the highest AR of 1,830 cases per 100,000 persons. Factors significantly associated with cholera infection were attending social gatherings (aOR = 2.04, 95% CI = 1.16–3.59) and drinking unsafe water (aOR = 1.74, 95% CI = 1.07–2.83). Conclusion Attending social gatherings and drinking unsafe water were risk factors for cholera infection. Public health actions included chlorination of wells and distribution of water guard (1% chlorine solution) bottles to households and public education on cholera prevention. We recommend the provision of safe drinking water by the government as well as improved sanitary and hygienic conditions for citizens of the state.
Assessing the mechanisms of multi-drug resistant non-typhoidal Salmonella (NTS) serovars isolated from layer chicken farms in Nigeria
In Nigeria, there have been reports of widespread multiple antimicrobial resistance (AMR) amongst Salmonella isolated from poultry. To mitigate the impact of mortality associated with Salmonella on their farms, farmers resort to the use of antimicrobials without sound diagnostic advice. We conducted this study to describe the AMR patterns, mechanisms and genetic similarities within some Salmonella serovars isolated from different layer farms. We determine the AMR profiles of two hundred Salmonella isolates, selected based on frequency, serovar, and geographical and sample type distribution. We also assessed the mechanisms of multi-drug resistance for specific genetic determinants by using PCR protocols and gene sequence analysis. Pulsed-field gel electrophoresis (PFGE) was conducted on seven selected serovars to determine their genetic relatedness. Of 200 isolates, 97 (48.5%) revealed various AMR profiles, with the multiple antibiotic resistance (MAR) index ranging from 0.07-0.5. Resistance to ciprofloxacin was common in all the multi-drug resistant isolates, while all the isolates were susceptible to cefotaxime, ceftazidime, and meropenem. Genotypic characterization showed the presence of resistance genes as well as mutations in the nucleotide genes with subsequent amino acid substitutions. Fifteen isolates (43%) of S. Kentucky were indistinguishable, but were isolated from four different states in Nigeria (Ogun, n = 9; Kaduna, n = 6; Plateau, n = 3, and: Bauchi, n = 2). PFGE revealed 40 pulsotype patterns (Kentucky, n = 12; Larochelle, n = 9; Virchow, n = 5; Saintpaul, n = 4; Poona, n = 3; Isangi, n = 2, and; Nigeria, n = 2). This study recorded strictly related but diversely distributed Salmonella serovars with high AMR rates in poultry. We recommend strict regulation on antimicrobial use and regular monitoring of AMR trends among bacteria isolated from animals and humans to inform public policy.
A Retrospective Study of the Seroprevalence of Dengue Virus and Chikungunya Virus Exposures in Nigeria, 2010–2018
Arboviruses are important public health threats in many regions of the world. Nigeria has experienced outbreaks of arboviruses over the past decades, leading to concerns of widespread endemicity, which are frequently misdiagnosed. This study aimed to determine the seroprevalence of dengue virus (DENV) (a flavivirus) and chikungunya virus (CHIKV) (an alphavirus) infections in three major population centers of Nigeria. A convenience sample of 701 sera was collected from both healthy and febrile participants between August 2010 and March 2018. Sera were tested for prior exposure to CHIKV virus and DENV using indirect IgG ELISA. Results showed that 54.1% (379/701) of participants were seropositive for anti-DENV antibodies, 41.3% (290/701) were seropositive for anti-CHIKV antibodies, and 20.1% (141/701) had previous exposure to both. The seropositivity for prior CHIKV exposure and prior exposure to DENV and CHIKV was significantly associated with age (CHIKV: OR = 2.7 (95% CI: 1.7–4.3); DENV and CHIKV: OR = 2.2 (95% CI: 1.2–4.0) for adults compared to participants under 18 years old). Overall, the high seropositivity across all age groups suggests that arboviral infections are prevalent in Nigeria and indicates that surveillance and further epidemiological studies are required to determine the true burden of these infections and the spectrum of diseases associated with these exposures.
Assessing the mechanisms of multi-drug resistant non-typhoidal Salmonella
In Nigeria, there have been reports of widespread multiple antimicrobial resistance (AMR) amongst Salmonella isolated from poultry. To mitigate the impact of mortality associated with Salmonella on their farms, farmers resort to the use of antimicrobials without sound diagnostic advice. We conducted this study to describe the AMR patterns, mechanisms and genetic similarities within some Salmonella serovars isolated from different layer farms. We determine the AMR profiles of two hundred Salmonella isolates, selected based on frequency, serovar, and geographical and sample type distribution. We also assessed the mechanisms of multi-drug resistance for specific genetic determinants by using PCR protocols and gene sequence analysis. Pulsed-field gel electrophoresis (PFGE) was conducted on seven selected serovars to determine their genetic relatedness. Of 200 isolates, 97 (48.5%) revealed various AMR profiles, with the multiple antibiotic resistance (MAR) index ranging from 0.07-0.5. Resistance to ciprofloxacin was common in all the multi-drug resistant isolates, while all the isolates were susceptible to cefotaxime, ceftazidime, and meropenem. Genotypic characterization showed the presence of resistance genes as well as mutations in the nucleotide genes with subsequent amino acid substitutions. Fifteen isolates (43%) of S. Kentucky were indistinguishable, but were isolated from four different states in Nigeria (Ogun, n = 9; Kaduna, n = 6; Plateau, n = 3, and: Bauchi, n = 2). PFGE revealed 40 pulsotype patterns (Kentucky, n = 12; Larochelle, n = 9; Virchow, n = 5; Saintpaul, n = 4; Poona, n = 3; Isangi, n = 2, and; Nigeria, n = 2). This study recorded strictly related but diversely distributed Salmonella serovars with high AMR rates in poultry. We recommend strict regulation on antimicrobial use and regular monitoring of AMR trends among bacteria isolated from animals and humans to inform public policy.
Prevalence and risk factors for multi-drug resistant Escherichia coli among poultry workers in the Federal Capital Territory, Abuja, Nigeria
Antimicrobial resistance has emerged as a global health threat. Antimicrobial resistant Escherichia coli infections are associated with high morbidity and expenditure when compared with infections caused by susceptible strains. In Nigeria, antimicrobial drugs are readily available over-the-counter with potential for indiscriminate use by poultry farmers and eventual development of drug resistance. The objective of this study was to investigate prevalence and risk factors for multi-drug resistant E. coli among poultry workers (PW) in Abuja, Nigeria. A cross-sectional study was conducted among 122 randomly selected apparently healthy poultry workers (poultry-farmers/ sellers) in Municipal and Kuje Area Councils from December 2018 to April 2019. Data was collected on socio-demographics and exposure factors using a structured interviewer-administered questionnaire. E. coli was isolated and identified from stool samples of poultry workers. Antibiotic susceptibility testing was done using Kirby-Bauer disk diffusion method. Multidrug resistance (MDR) was defined as resistance to three or more classes of antimicrobials. Data was analyzed by computing proportions, prevalence odds-ratios (POR) and logistic regression at 5% significance level. Among PW, there were 121 males (99.2%). Mean age of the male workers was 30.6 ± 9.7years, 54.6% (n = 66) married, 57.9% (n = 70) had secondary education and 62.0% (n = 75) were farm-workers. Prevalence of E. coli was 39.7% (n = 48), highest among farm-workers (POR = 2.7, 95% Confidence Interval [CI] = 1.3-5.7; p = 0.01) compared to poultry-sellers. Of the 48 E. coli isolates, 16.7% (n = 8) were extended spectrum beta lactamase (ESBL) producers and 79.2% (n = 38) were MDR. We detected resistance against Tetracycline: (83.3%, n = 40), Sulfamethoxazole-Trimethoprim: (79.2%, n = 38), Ampicillin: (77.1%, n = 37), Streptomycin: (72.9%, n = 35), Nalidixic acid: (50%, n = 24), Gentamicin: (41.7%, n = 20), Chloramphenicol: (31.3%, n = 15), Cephalothin: (27.1%, n = 13), Nitrofurantoin: (10.4%, n = 5) and Imipenem: (6.3%, n = 3). Absence of lavatory (POR = 2.7, 95% CI = 1.1-6.7); existence of farm/market for >10years (POR = 2.5, 95% CI = 1.1-5.4) and PW's history of diarrhea in last three months (POR = 2.8, CI = 1.2-6.3) were associated with MDR. Controlling for age, absence of lavatory (adjusted OR [aOR] = 4.31, 95% CI = 1.6-11.9); PW's history of diarrhea in last three months (aOR = 3.3,95%CI = 1.3-8.5) and work exposure >10years (aOR = 0.3, 95%CI = 0.1-0.9) remained independent risk factors for MDR. Prevalence of resistant E. coli was highest among farm-workers and associated with older farms/markets, occupational exposure of over 10 years and poor hygienic measures. The management of Municipal and Kuje Area Councils were recommended to provide lavatories for public use in farm-settlements/markets. The importance of hand-hygiene and responsible use of antimicrobials in poultry production was emphasized.
Genetic relatedness of multidrug resistant Escherichia coli isolated from humans, chickens and poultry environments
Background Inappropriate use of antimicrobial agents in animal production has led to the development of antimicrobial resistance (AMR) in foodborne pathogens. Transmission of AMR foodborne pathogens from reservoirs, particularly chickens to the human population does occur. Recently, we reported that occupational exposure was a risk factor for multidrug-resistant (MDR) Escherichia coli (E. coli) among poultry-workers. Here we determined the prevalence and genetic relatedness among MDR E. coli isolated from poultry-workers, chickens, and poultry environments in Abuja, Nigeria. This study was conducted to address the gaps identified by the Nigerian AMR situation analysis. Methods We conducted a cross-sectional study among poultry-workers, chickens, and poultry farm/live bird market (LBM) environments. The isolates were tested phenotypically for their antimicrobial susceptibility profiles, genotypically characterized using whole-genome sequencing (WGS) and in silico multilocus sequence types (MLST). We conducted a phylogenetic single nucleotide polymorphism (SNPs) analysis to determine relatedness and clonality among the isolates. Results A total of 115 (26.8%) out of 429 samples were positive for E. coli. Of these, 110 isolates were viable for phenotypic and genotypic characterization. The selection comprised 47 (42.7%) isolates from poultry-workers, 36 (32.7%) from chickens, and 27 (24.5%) from poultry-farm or LBM environments. Overall, 101 (91.8%) of the isolates were MDR conferring resistance to at least three drug classes . High frequency of resistance was observed for tetracycline (n = 102; 92.7%), trimethoprim/sulfamethoxazole (n = 93; 84.5%), streptomycin (n = 87; 79.1%) and ampicillin (n = 88; 80%). Two plasmid-mediated colistin genes— mcr-1.1 harboured on IncX4 plasmids were detected in environmental isolates. The most prevalent sequence types (ST) were ST-155 (n = 8), ST-48 (n = 8) and ST-10 (n = 6). Two isolates of human and environmental sources with a SNPs difference of 6161 originating from the same farm shared a novel ST. The isolates had similar AMR genes and plasmid replicons. Conclusion MDR E.coli isolates were prevalent amongst poultry-workers, poultry, and the poultry farm/LBM environment. The emergence of MDR E. coli with novel ST in two isolates may be plasmid-mediated. Competent authorities should enforce AMR regulations to ensure prudent use of antimicrobials to limit the risk of transmission along the food chain.
Quinolone-resistant Escherichia coli at the interface between humans, poultry and their shared environment- a potential public health risk
Background Commensal Escherichia coli residing in the guts of humans and animals are reservoirs of multidrug resistance (MDR) genes, including quinolone resistance genes, in humans and poultry. This study aimed to characterize quinolones resistance in E. coli recovered from poultry workers, chickens, and poultry farm/market environments in Abuja, Nigeria. Methods This was a cross-sectional study conducted between December 2018 and April 2019 comprising poultry workers, chickens and their poultry farm/market environments. This study characterized E. coli isolates from stool, faecal and environmental samples using antimicrobial susceptibility testing and whole-genome sequencing methods. Core-genome multilocus sequences-based phylogeny was used to determine the relatedness between quinolone-resistant E. coli isolates. Data were analyzed using descriptive statistics. Results Of 110 E. coli isolates, quinolone-resistant phenotypes were observed in 68.2% ( n  = 75) isolates. Whole-genome sequencing detected plasmid-mediated quinolone resistance (PMQR) genes in 63.6% ( n  = 70) isolates. The most prevalent PMQR gene detected in 56 of these 70 E. coli isolates was qnrS1 , followed by qnrB19 in 14 isolates and aac(6’)-lb-cr in two isolates. Fifteen ciprofloxacin and 19 nalidixic acid-resistant isolates respectively showed double mutations in the quinolone-resistance determining regions (QRDRs) of gyrA , with single or double mutations in parC , and a single mutation in parE . The most prevalent amino-acid substitutions observed were S83L + D87N in gyrA (46.5%, n  = 20), S80I in parC (51.2%, n  = 22) and S458A in parE (14%, n  = 6). About 2.9% (2/70) of PMQR isolates were extended-spectrum beta-lactamase (ESBL) producers while 2.9% (2/70) had plasmid-mediated colistin resistance (PMCR) genes. Conclusions PMQR genes were prevalent in E. coli isolates recovered from healthy humans, chickens and poultry farm/market environments. PMCR genes ( mcr-1.1 ) occurred in PMQR-positive isolates recovered from manure and drinking water originating from poultry farm/market environments. It was found that the gene encoding ESBL coexisted with qnrS- positive isolates of human and avian origin. Horizontal transfer of PMQR genes among E. coli isolates in the human-poultry-environment interface has public health implications for the spread of antimicrobial resistance. Relevant government agencies should enforce regulations to restrict the use of critically important antimicrobials in poultry production.
Enhancing clinical microbiology for genomic surveillance of antimicrobial resistance implementation in Africa
Surveillance is essential in the fight against antimicrobial resistance (AMR), to monitor the extent of resistance, inform prevention, control measures, and evaluate intervention progress. Traditional surveillance methods based on phenotypic antimicrobial susceptibility data offer important but limited insights into resistance mechanisms, transmission networks, and spread patterns of resistant bacterial strains. Fortunately, genomic technologies are increasingly accessible and can overcome these limitations. Genomics has the potential to advance traditional bacteriology in routine diagnosis and surveillance, it often relies on the initial isolation of bacterial strains from clinical specimens using conventional culture methods. Culture-based phenotypic characteristics are essential for making inferences about newly recognized genomic patterns. The Africa CDC Pathogen Genomics Initiative (Africa PGI) aims to enhance disease surveillance and public health partnerships through integrated, cross-continent laboratory networks equipped with the tools, human resource capacity and data infrastructure to fully leverage critical genomic sequencing technologies. For genomic surveillance of AMR, it is essential to optimize routine clinical microbiology laboratory services that are weak in many African countries. In this review, we outline shortcomings in clinical microbiology laboratories across Africa that compromise pathogen genomic epidemiology. We emphasize the necessity of investing in bacteriology and enhancing leadership capacity to fully capitalize on the advantages offered by genomic antimicrobial resistance (AMR) surveillance.