Antimicrobial resistance genetic determinants and susceptibility profile of Pseudomonas aeruginosa isolated from clinical samples in a tertiary hospital in Ogun State, Nigeria.

BACKGROUND: Genetic determinants are known to promote antibiotic resistance through horizontal gene transfer. METHODS: We molecularly characterized integrons, plasmid replicon types and metallo-ß-lactamase-encoding genes of 38 Pseudomonas aeruginosa strains isolated from clinical samples. RESULTS: The P. aeruginosa isolates displayed high resistance (97.4%) to ß-lactams. Seventeen (44.74%) of them possessed plasmids. Of the 17 isolates that possessed plasmids, 11 (64.7%) of them harboured IncFIA plasmid replicon type, while 6 (35.3%), 5 (29.4%) and 5 (29.4%) were of the IncFIB, IncF and IncW types, respectively. The intI1 gene was detected in 19 (50%) of the isolates. The blaNDM-A, blaNDM-B and blaVIM genes were detected in 14 (35.9%), 4 (10.3%) and 5 (12.8%) of the isolates, respectively. CONCLUSIONS: High resistance to ß-lactams was observed among P. aeruginosa strains of clinical origin in this study. They possessed transmissible genetic elements indicating the potential for continuous dissemination, thus continuous surveillance is advocated.

Helicobacter pylori diagnosis and treatment in Africa: The First Lagos Consensus Statement of the African Helicobacter and Microbiota Study Group (AHMSG).

BACKGROUND: Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aims to create an Africa-specific consensus report reflecting Africa-specific issues. SUMMARY: Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members. KEY MESSAGES: There is need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.

Antibiotic Resistance and Plasmid Replicon Types of Non-Typhoidal Salmonella Serovars Isolated From Food Animals and Humans in Lagos, Nigeria.

Multidrug resistance and invasiveness of non-typhoidal Salmonella (NTS) serovars have in recent times brought to the fore the public health risk associated with salmonellosis. This study was aimed at profiling NTS serovars isolated from food animals and humans for their susceptibility to antibiotics and plasmid replicon types. Forty seven NTS serovars were profiled for their susceptibility to antibiotics using the disk diffusion method. Polymerase chain reaction based replicon typing assay was used for profiling plasmid replicon types detected in Salmonella isolates. High rate of resistance were found for amoxicillin/clavulanic acid (40/47; 85.1%), cefuroxime (38/47; 80.9%) and ceftazidime (30/47; 63.8%). Thirty one (65.9%) and 33 (70.2%) showed intermediate resistance to ofloxacin and ciprofloxacin respectively. Plasmids of sizes ranging from 14.3 to 16.7 kb were detected in 24 (51.1%) of Salmonella isolates with some serovars harbouring multiple plasmids. FIA, FIB, Frep and W plasmid replicon types were detected in 11, 4, 2 and 1 of the Salmonella isolates respectively. Three of the isolates harboured both FIA and FIB replicon types. The high rate of resistance to ß-lactams observed in Salmonella serovars harbouring different plasmid replicon types in this study highlight potential public health threat and the need for prudent use of antibiotics in human and veterinary medicine.

Comparative Molecular Analysis and Antigenicity Prediction of an Outer Membrane Protein (ompC) of Non-typhoidal Salmonella Serovars Isolated from Different Food Animals in Lagos, Nigeria.

Non-typhoidal Salmonella (NTS) infections occur globally with high morbidity and mortality. The public health challenge caused is exacerbated by increasing rate of antibiotic resistance and absence of NTS vaccine. In this study, we characterized the outer membrane protein C (OmpC) serovars isolated from different food animals and predicted antigenicity. ompC of 27 NTS serovars were amplified by polymerase chain reaction (PCR) and sequenced. Sequence data were analysed and B-cell epitope prediction was done by BepiPred tool. T-cell epitope prediction was done by determining peptide-binding affinities of major histocompatibility complex (MHC) classes I and II using NetMHC pan 2.8 and NetMHC-II pan 3.2, respectively. ompC sequence analysis revealed conserved region among ompCs of Salmonella Serovars. A total of 66.7% of ompCs were stable with instability index value < 40 and molecular weight that ranged from 27 745.47 to 32 714.32 kDa. All ompCs were thermostable and hydrophilic with the exception of S. Pomona (14p) isolate that had ompC with GRAVY value of 0.028 making it hydrophobic. Linear B-cell epitope prediction revealed ability of ompC to elicit humoral immunity. Multiple B-cell epitopes that were exposed and buried were observed on several positions on the ompC sequences. T-cell epitope prediction revealed epitopes with strong binding affinity to MHC-I and -II. Strong binding to human leukocyte antigen (HLA-A) ligands, including HLA-A03:1, HLA-A24:02 and HLA-A26:01 in the case of MHC-I were observed. While binding affinity to H-2 IAs, H-2 IAq and H-2 IAu (H-2 mouse molecules) were strongest in the case of MHC-II. ompCs of NTS serovars isolated from different food animal sources indicated ability to elicit humoral and cell-mediated immunity. Hence, ompCs of NTS serovars are potential candidate for production of NTS vaccines.

Antibiotic prescription practices amongst veterinarians in Nigeria.

The high rate of antibiotic resistance constitutes a global threat to the continuous use of these drugs, because of increasing treatment failures. The aim of this study was to survey antibiotic prescription practices of veterinarians and the possible contribution to antimicrobial resistance (AMR) and antimicrobial stewardship (AMS) in Nigeria during the COVID era. This was a cross-sectional study that used a 33-question survey questionnaire administered to registered veterinarians in Nigeria. The study was both online survey and hard copy administered during the annual meeting of the veterinarians from July to October 2021. Descriptive statistics, bivariate analysis using Chi-square test were also done to analyze the results, while a two-tailed P-value of <0.05 at 95% confidence level was considered statistically significant. IBM SPSS Version 26 was used to analyze the data. A total of 172 respondents completed the online and hard copy questionnaire. Majority of the respondents engaged majorly in mixed veterinary practice (72.1%). A total of 53.5% were aware of the country's policy concerning antibiotic prescription, while majority (64.5%) do not do culture and sensitivity before antibiotic prescription. Majority (34.3%) felt that the risk of potential adverse drug reaction could affect their decision when choosing to prescribe an antibiotic to the owner. Majority (51.2%) felt that some antibiotics were over prescribed, while 26.7% opined that all antibiotics were appropriately prescribed. To improve antibiotic use and practice amongst veterinarians in Nigeria, dependence on laboratory services for antibiotic prescription, enforcement of national guidelines and monitoring of antibiotic prescription amongst the veterinarians is essential to curb over-prescription and strengthen antimicrobial stewardship.

Helicobacter pylori Infection in Africa: Update of the Current Situation and Challenges.

BACKGROUND: The burden of Helicobacter pylori infection (HPI) in Africa remains high with varying levels of prevalence among children and adults reported in different regions of the continent. Persistent and uneradicated HPI could result in gastric cancer, although less severe pathological outcomes have been reported among Africans - the so-called "African enigma." SUMMARY: Analysis of endoscopic findings of the upper gastrointestinal tract demonstrates similarities with that of patients from the West. Thus, it could be asserted that the true picture of HPI in Africa is yet to be unveiled due to several challenges including inadequate health-care system, lack of treatment guidelines and standardized protocol for diagnosis, and lack of data. This review explores the prevalence, diagnosis, treatment, and health-care system in Africa as it relates to HPI, thus providing an update and highlighting the need for an African HPI guideline. KEY MESSAGES: There is high prevalence of Helicobacter pylori infection (HPI) in Africa with an increasing burden of antibiotic resistance. Various methods including invasive and noninvasive methods are deployed in the diagnosis of HPI in Africa. There is a need for consensus on diagnosis and treatment of HPI in Africa.

Molecular and phenotypic characterization of efflux pump and biofilm in multi-drug resistant non-typhoidal Salmonella Serovars isolated from food animals and handlers in Lagos Nigeria.

BACKGROUND: Multidrug resistance efflux pumps and biofilm formation are mechanisms by which bacteria can evade the actions of many antimicrobials. Antibiotic resistant non-typhoidal Salmonella serovars have become wide spread causing infections that result in high morbidity and mortality globally. The aim of this study was to evaluate the efflux pump activity and biofilm forming capability of multidrug resistant non-typhoidal Salmonella (NTS) serovars isolated from food handlers and animals (cattle, chicken and sheep) in Lagos. METHODS: Forty eight NTS serovars were subjected to antibiotic susceptibility testing by the disc diffusion method and phenotypic characterization of biofilm formation was done by tissue culture plate method. Phenotypic evaluation of efflux pump activity was done by the ethidium bromide cartwheel method and genes encoding biofilm formation and efflux pump activity were determined by PCR. RESULTS: All 48 Salmonella isolates displayed resistance to one or more classes of test antibiotics with 100% resistance to amoxicillin-clavulanic acid. Phenotypically, 28 (58.3%) of the isolates exhibited efflux pump activity. However, genotypically, 7 (14.6%) of the isolates harboured acrA, acrB and tolC, 8 (16.7%) harboured acrA, acrD and tolC while 33 (68.8%) possessed acrA, acrB, acrD and tolC. All (100%) the isolates phenotypically had the ability to form biofilm with 23 (47.9%), 24 (50.0%), 1 (2.1%) categorized as strong (SBF), moderate (MBF) and weak (WBF) biofilm formers respectively but csgA gene was detected in only 23 (47.9%) of them. Antibiotic resistance frequency was significant (p < 0.05) in SBF and MBF and efflux pump activity was detected in 6, 21, and 1 SBF, MBF and WBF respectively. CONCLUSION: These data suggest that Salmonella serovars isolated from different food animals and humans possess active efflux pumps and biofilm forming potential which has an interplay in antibiotic resistance. There is need for prudent use of antibiotics in veterinary medicine and scrupulous hygiene practice to prevent the transmission of multidrug resistant Salmonella species within the food chain.

Evaluation of efflux pump activity and biofilm formation in multidrug resistant clinical isolates of Pseudomonas aeruginosa isolated from a Federal Medical Center in Nigeria.

BACKGROUND: Pseudomonas aeruginosa an opportunistic pathogen, is widely associated with nosocomial infections and exhibits resistance to multiple classes of antibiotics. The aim of this study was to determine the antibiotic resistance profile, biofilm formation and efflux pump activity of Pseudomonas strains isolated from clinical samples in Abeokuta Ogun state Nigeria. METHODS: Fifty suspected Pseudomonas isolates were characterized by standard biochemical tests and PCR using Pseudomonas species -specific primers. Antibiotic susceptibility testing was done by the disc diffusion method. Efflux pump activity screening was done by the ethidium bromide method and biofilm formation assay by the tissue plate method. Genes encoding biofilm formation (pslA & plsD) and efflux pump activity (mexA, mexB and oprM) were assayed by PCR. RESULTS: Thirty-nine Pseudomonas spp. were identified of which 35 were Pseudomonas aeruginosa and 4 Pseudomonas spp. All 39 (100%) Pseudomonas isolates were resistant to ceftazidime, cefuroxime and amoxicillin-clavulanate. Thirty-six (92%), 10(25.6%), 20 (51.2%), 11(28%) and 9(23%) of the isolates were resistant to nitrofurantoin, imipenem, gentamicin, cefepime and aztreonam respectively. All the isolates had the ability to form biofilm and 11 (28%) of them were strong biofilm formers. They all (100%) harboured the pslA and pslD biofilm encoding genes. Varied relationships between biofilm formation and resistance to ciprofloxacin, ofloxacin, cefixime, gentamicin, imipenem, and aztreonam were observed. Only 23(59%) of the Pseudomonas isolates phenotypically exhibited efflux pump activity but mexA gene was detected in all 39 (100%) isolates while mexB and oprM genes were detected in 91%, 92%, and 88% of strong, moderate and weak biofilm formers respectively. CONCLUSION: Multidrug resistance, biofilm and efflux pump capabilities in Pseudomonas aeruginosa have serious public health implications in the management of infections caused by this organism.

Evolving Technologies in Gastrointestinal Microbiome Era and Their Potential Clinical Applications.

The human gastrointestinal microbiota (GIM) is a complex and diverse ecosystem that consists of community of fungi, viruses, protists and majorly bacteria. The association of several human illnesses, such as inflammatory bowel disease, allergy, metabolic syndrome and cancers, have been linked directly or indirectly to compromise in the integrity of the GIM, for which some medical interventions have been proposed or attempted. This review highlights and gives update on various technologies, including microfluidics, high-through-put sequencing, metabolomics, metatranscriptomics and culture in GIM research and their applications in gastrointestinal microbiota therapy, with a view to raise interest in the evaluation, validation and eventual use of these technologies in diagnosis and the incorporation of therapies in routine clinical practice.

Efflux pump activity, biofilm formation and antibiotic resistance profile of Klebsiella spp. isolated from clinical samples at Lagos University Teaching Hospital.

OBJECTIVE: Nosocomial and community acquired multidrug resistant Klebsiella infections are wide spread resulting in high morbidity and mortality due to limited number of antibiotics treatment options. This study investigated efflux pump activity, biofilm forming potential and antibiotic susceptibility profile of Klebsiella spp. isolated from clinical samples in a tertiary hospital in Lagos Nigeria. Eighteen clinical Klebsiella spp. isolated from urine, blood and sputum were subjected to antibiotic susceptibility testing using the disc diffusion method. Efflux pump activity was evaluated by the ethidium bromide cartwheel method and biofilm forming ability was determined by the tissue culture plate technique. RESULTS: All 18 (100%) Klebsiella isolates were resistant to cefuroxime, cefixime, amoxicillin - clavulanate, ampicillin + cloxacillin, cefotaxime, and imipenem. Seventeen (94.4%) were resistant to ofloxacin while sixteen (88.9%) were resistance to nalidixic acid, Gentamicin and levofloxacin. All Klebsiella isolates possessed active efflux pump with the ability to form biofilm. However, their biofilm forming capabilities varied as 4 (22.2%) were strong, 3 (16.7%) were moderate and 11 (61.1%) were weak biofilm formers. Findings in this study reveal multiple factors at play in mediating the high level of antibiotic resistance observed in Klebsiella isolates. Hence a multifaceted approach is advocated in managing the infections caused by the pathogen.

Molecular diversity and antibiotic resistance gene profile of Salmonella enterica serovars isolated from humans and food animals in Lagos, Nigeria.

Outbreaks of Salmonellosis remain a major public health problem globally. This study determined the diversity and antibiotic resistance gene profile of Salmonella enterica serovars isolated from humans and food animals. Using standard methods, Salmonella spp. were isolated from fecal samples, profiled for antimicrobial susceptibility and resistance genes. Seventy-one Salmonella isolates were recovered from both humans and food animals comprising cattle, sheep, and chicken. Forty-four serovars were identified, with dominant Salmonella Budapest (31.8%). Rare serovars were present in chicken (S. Alfort, S. Wichita, S. Linton, S. Ealing, and S. Ebrie) and humans (S. Mowanjum, S. Huettwillen, S. Limete, and S. Chagoua). Sixty-eight percent of isolates were sensitive to all test antibiotics, while the highest rate of resistance was to nalidixic acid (16.9%; n = 12), followed by ciprofloxacin (11.3%; n = 8) and tetracycline (9.9%; n = 8). Five isolates (7%) were multidrug-resistant and antimicrobial resistance genes coding resistance to tetracycline (tetA), beta-lactam (blaTEM), and quinolone/fluoroquinolone (qnrB and qnrS) were detected. Evolutionary analysis of gyrA gene sequences of human and food animal Salmonella isolates revealed variations but are evolutionarily interconnected. Isolates were grouped into four clades with S. Budapest isolate from cattle clustering with S. Budapest isolated from chicken, whereas S. Essen isolated from sheep and chicken was grouped into a clade. Diverse S. enterica serovars with high antibiotic resistance profile are ubiquitous in food animals; hence, there is a need for surveillance and prudent use of antibiotics in human and veterinary medicine.

Antibiotic Susceptibility Profiles of Campylobacter coli Isolated from Poultry Farms in Lagos Nigeria - A Pilot Study.

Campylobacter jejuni and Campylobacter coli are among the leading causes of gastroenteritis in humans worldwide, particularly in Africa. Poultry remains a major source of Campylobacter species and a vector of transmission to humans. This pilot study was aimed at isolating and determining the antibiotic susceptibility profiles of Campylobacter spp. from fresh poultry droppings collected from poultry farms in Lagos State, Nigeria. Susceptibility was assessed using the CLSI standards. Standard microbiological methods were used in isolation, identification, and characterization of Campylobacter spp. Isolates were subjected to antibiotic susceptibility testing by the disk diffusion method. Of the 150 poultry droppings analyzed, 8 (5.3%) harbored Campylobacter spp. All isolates proved to be C. coli since they were all negative for the hip gene. A percentage of 100% showed resistance to nalidixic acid, chloramphenicol, cloxacillin, and streptomycin. While 87.5% were susceptible to amoxicillin and amoxicillin/clavulanic acid, 62.5% were susceptible to tetracycline. Surprisingly, 62.5% of C. coli had decreased (intermediate) susceptibility to erythromycin. Although there was a low prevalence of C. coli from poultry in this study, the presence of antibiotic resistant strains circulating the food chain could result in treatment failures and difficulty in case management if involved in infections of humans.

Correction to: Recurrent cholera epidemics in Africa: which way forward? A literature review.

The original version of this article unfortunately contained a mistake. In the introduction, the infectious dose of Vibrio cholerae was written as 103-108 instead of 103-108 cells.

Recurrent cholera epidemics in Africa: which way forward? A literature review.

BACKGROUND: Outbreaks of cholera in Africa seem to be unrelenting which has been continuous and recurrent leading to high morbidity and mortality in some quarters. OBJECTIVE: The objective of this narrative review is to investigate and identify factors responsible for the recurrent outbreaks of cholera in Africa and response strategies that have been employed in curbing the problem, with the view of aggregating otherwise sparing data needed for policy formulation geared towards control and eradication of the disease. METHODS: Search of literatures indexed in Google Scholar, PubMed and AJOL databases was carried out. Sixty-five eligible articles with reports on the risk factors that drive recurrent outbreaks, endemicity and response strategies were analyzed. RESULTS: Our findings indicate that continuous and recurrent outbreaks of cholera in Africa are fueled by cross-border migration, environmental reservoirs, socioeconomic factors, climate change and political instability. The review also identified specific response strategies and modelling approaches that have helped in containing and reducing the impact of these outbreaks. CONCLUSION: Paying attention and tackling these identified factors that are dependent and independent can help put an end to this running battle.

Distribution of resistance genes encoding ESBLs in Enterobacteriaceae isolated from biological samples in health centers in Ouagadougou, Burkina Faso.

OBJECTIVE: Resistance to antibiotics most especially third generation cephalosporins has assumed a worrisome dimension globally. Genes conferring these resistance which are mediated by enzymes known as extended spectrum beta-lactamases (ESBLs) are now wide spread among several Enterobacteriaceae species. However there is paucity of data regarding the distribution of these genes in Burkina Faso. Hence this prospective study aims to determine the prevalence and distribution of ESBL encoding genes in ESBL producing Enterobacteriaceae strains isolated from clinical samples of patients attending the three major hospitals in Ouagadougou Burkina Faso. RESULTS: ESBL-encoding genes were assayed in 187 ESBL producing Enterobacteriaceae strains. Among these isolates, the prevalence of ESBL-producing strains with blaTEM, blaSHV and blaCTX-M genes were 26.2% (49/187), 5.9% (11/187) and 40.1% (75/187) respectively. The association of ESBL encoding genes with health centers was statistically significant (p = 0.0209). Approximately 39.6% of E. coli harbored CTX-M and Klebsiella spp. 5.9%. This study demonstrates the dissemination of TEM, SHV and CTX-M genes in ESBL producing Enterobacteriaceae strains in Ouagadougou. Continuous spread of these bacteria poses great public health risk, thus increased surveillance and regulation of antibiotics use is imperative in Burkina Faso.