The global burden of human and animal brucellosis remains enormous. The disease, which is endemic in Nigeria, lacks appropriate attention and national data. This review estimated the burden and distribution of human and animal brucellosis in Nigeria in the last twenty-one years (2001–2021). Publications reporting the detection of brucellosis in Nigeria were sorted from different search engines, including PubMed, ResearchGate, Scopus, and Google Scholar, to generate data on its prevalence, spatial distribution, and predisposing factors. The results of the national seroprevalence of human and animal brucellosis as revealed in this study were 17.6% (554/3144) and 13.3% (8547/64,435), respectively. Specifically, 15.8% (7178/45,363) seroprevalence of brucellosis was recorded in northern Nigeria as against 8.7% (1902/21,740) seroprevalence in the southern part. It also indicated that 78.7% of the detected brucellae were un-typed. The Brucella species detected were B. abortus (15.2%), B. melitensis (4%), B. suis (1.8%), and B. canis (0.4%). This study revealed that brucellosis is endemic in Nigeria. Culture and molecular methods for detecting brucellosis and reports on antimicrobial susceptibility testing remain a conjecture. This review will help researchers redirect their research focus and serve as a guide for policymakers on measures for managing brucellosis in Nigeria.

Purpose: The global spread of bla_CTX-M-I extended-spectrum beta-lactamase (ESBL)-producing Salmonella spp. remains a major threat to treatment and control. Evidence of emergence and spread of this marker are lacking in Nigeria. This study investigated bla_CTX-M-I ESBL production among Salmonella isolates from hospitalized patients. Methods: Patients (158 total) made up of two groups were evaluated. Group A was composed of 135 patients with persistent pyrexia and group B was composed of 23 gastroenteritis patients and their stool samples. Samples were cultured, and isolates were identified and were subjected to antibiotic susceptibility testing by standard methods. Isolates were further screened for ESBL production, bla_CTX-M-I genes and transferability by double disk synergy test, plasmid extraction, polymerase chain reaction, and conjugation experiment. Results: Thirty-five (25.9%) Salmonella isolates were identified from group A, of which 74.3% were S. typhi, 22.9% were S. paratyphi and two (5.7%) were invasive non-typhoidal S. enteritidis. Nine Plasmodium falciparum infections were recorded, four of which were identified as co-infections with typhoidal Salmonella. Only two (8.7%) S. enteritidis samples were obtained from group B (P>0.05). A total of 24 isolates were ESBL-positive, eliciting resistance to five to seven antibiotics, and were multiple-drug resistant. ESBL production due to the bla_CTX-M-I gene cluster was detected in eleven (45.8%) Salmonella isolates. Nine (81.8%) of the eleven bla_CTX-M-I ESBL producers were S. typhi and two (18.2%) isolates were S. enteritidis. Four of nine S. typhi bla_CTX-M-I ESBL-producing strains harbored 23 kb self-transmissible plasmid that was co-transferred with cefotaxime and augmentin resistance to Escherichia coli j53-2 transconjugants. Conclusion: This study revealed the emergence of bla_CTX-M-I S. typhi as an agent of persistent pyrexia with potential to spread to other Enterobacteriaceae in Lagos, Nigeria. Cautionary prescription and judicious use of third-generation cephalosporins, particularly cefotaxime, for the treatment of typhoid fever and routine screening for P. falciparum co-infection with ESBL-producing Salmonella in the laboratories during diagnosis of persistent pyrexia conditions in patients are recommended.

This study investigated the prevalence of Klebsiella (K.) pneumoniae isolates among clinical samples of patients in four medical centers in Lagos, Nigeria and the burden of extended-spectrum beta-lactamases (ESBL) and carbapenem-resistant K. pneumoniae (CRKP) strains. Different samples (stool, blood, urine, wound swabs and nasal swabs) from 127 patients with suspected Gram-negative infections based on on-site performed Gram-stain from four public hospitals between March and September 2015 were analyzed. K. pneumoniae was identified in 43 (34%) patients. Resistance rates of these 43 strains according to the CLSI breakpoints were as followed: cotrimoxazole (90.7%), cefuroxime (74.4%), ofloxacin (55.8%), ceftazidime (46.5%), and cefixime (35%). Three isolates (7%) were resistant to imipenem. All isolates were susceptible to amoxicillin/clavulanic acid and nitrofurantoin. The prevalence of ESBL-producing, MDR and CRKP strains was 69.8%, 62.8%, and 7.0%, respectively. Of the ESBL-producing isolates, two K. pneumoniae isolates obtained from urine harbored both bla_SHV and bla_CTX-M-1, and a third isolate from urine harbored only the bla_CTX-M-1. This study revealed the emergence of CRKP isolates and bla_CTX-M-1 and bla_SHV co-harboring K. pneumoniae strains in Lagos hospitals. The emergence of CRKP strains is an early warning signal for carbapenem antibiotics’ prudent use with concern for their efficacies.

Purpose: Salmonella spp. are important foodborne pathogens exhibiting increasing resistance to antimicrobial drugs. Resistance to broad-spectrum β-lactams, mediated by extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase enzymes is fast spreading and has had negative impacts on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria. Methods: Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S. enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4) were subjected to in vitro susceptibility test by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins were screened for ESBL (Double Disk Synergy Test Method) and AmpC enzyme (AmpC disk test) production. Detection of AmpC fox gene was carried out by polymerase chain reaction. Results: Thirty-two (80%) of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated AmpC β-lactamase and ESBL enzymes were recorded in 10/40 (25%) and 16/40 (40%) of the Salmonella isolates, respectively. Specifically, 16/40 (40%) of the Salmonella isolates possessed 380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8%) followed by S. typhimurium (25%). There was no AmpC fox gene detected in S. paratyphi strains. Interestingly, coproduction of enzymes occurred in some of the isolates, raising fears of resistance to a multitude of antibiotics in the treatment of bacterial infections. Conclusion: Emergence of AmpC β-lactamase–producing Salmonella isolates in our environment was recorded for the first time, raising concern on increased antibiotic resistance among strains of Salmonella serovars in Lagos. Further genotypic study of the isolates could answer the questions on strain sources, clonal relatedness, and mechanism of spread.

Background: Typhoid fever is endemic in Nigeria, and there are no high-quality routine diagnostic tests. Immunodiagnostic assays, blood culture, and quantitative real-time polymerase chain reaction (qPCR) were used to study typhoid fever co-infection with malaria. Materials & Methods: Blood samples of 125 patients were taken from April to August 2021. ...

Aim: This study investigated the cultural method and 16S rRNA gene analysis to reveal the composition and diversity of lactic acid bacteria (LAB) from dairy origin (spontaneous fermented cow milk) in Nigeria. Methods: Six dairy samples which includes two raw cow milk, two raw goat milk and two fermented cow milk (nono) were collected and subjected to standard microbiological investigation using both cultural and molecular methods. The dairy samples were cultured on MRS media, and the isolates were identified using physiological and biochemical parameters. DNA of four selected probiotic LAB isolates from nono were amplified using PCR while the amplicons were electrophoresed in agarose gel, pre-stained with ethidium bromide and characterized by 16S rRNA gene analysis. The result of the DNA sequencing were analyzed using NCBI BLAST. Results: A total of 55 presumptive LAB were isolated. Twenty nine (29) Lactobacillus plantarum representing 52.7%, Pediococcus acidilactici 15(27.2%), Lactobacillus casei and Lactobacillus brevis 4(7.3%) while Lactobacillus fermentum 3(5.5%) were recorded respectively. Result of the gel electrophoresis revealed DNA size of approximately 1500bp. The selected probiotic LAB from nono used in this study were confirmed as Lactobacillus plantarum N17, Lactobacillus plantarum N24, Lactobacillus brevis N10 and Lactobacillus casei N1 based on 16S rRNA gene sequence analysis while the phylogenetic analysis revealed a 98-100% similarity with a high homology level which affirms the strain of the organism. Conclusion: This study has demonstrated the diversity of LAB existing in dairy samples known as fermented cow milk (nono) which could be harnessed as valuable sources for LAB isolation and potential probiotic organisms.