Performance evaluation of SARS-CoV-2 rapid diagnostic tests in Nigeria: A cross-sectional study.

The COVID-19 pandemic challenged health systems globally. Reverse transcription polymerase chain reaction (RT-PCR) is the gold standard for detecting the presence of SARS-CoV-2 in clinical samples. Rapid diagnostic test (RDT) kits for COVID-19 have been widely used in Nigeria. This has greatly improved test turnover rates and significantly decreased the high technical demands of RT-PCR. However, there is currently no nationally representative evaluation of the performance characteristics and reliability of these kits. This study assessed the sensitivity, specificity, and predictive values of ten RDT kits used for COVID-19 testing in Nigeria. This large multi-centred cross-sectional study was conducted across the 6 geo-political zones of Nigeria over four months. Ten antigen (Ag) and antibody (Ab) RDT kits were evaluated, and the results were compared with RT-PCR. One thousand, three hundred and ten (1,310) consenting adults comprising 767 (58.5%) males and 543 (41.5%) females participated in the study. The highest proportion, 757 (57.7%), were in the 20-39 years' age group. In terms of diagnostic performance, Lumira Dx (61.4, 95% CI: 52.4-69.9) had the highest sensitivity while MP SARS and Panbio (98.5, 95% CI: 96.6-99.5) had the highest specificity. For predictive values, Panbio (90.7, 95% CI: 79.7-96.9) and Lumira Dx (81.2, 95% CI: 75.9-85.7) recorded the highest PPV and NPV respectively. Ag-RDTs had better performance characteristics compared with Ab-RDTs; however, the sensitivities of all RDTs in this study were generally low. The relatively high specificity of Ag-RDTs makes them useful for the diagnosis of infection in COVID-19 suspected cases where positive RDT may not require confirmation by molecular testing. There is therefore the need to develop RDTs in-country that will take into consideration the unique environmental factors, interactions with other infectious agents, and strains of the virus circulating locally. This may enhance the precision of rapid and accurate diagnosis of COVID-19 in Nigeria.

Fecal Carriage of Colibactin-Encoding Escherichia coli Associated With Colorectal Cancer Among a Student Populace.

Fecal carriage of the colibactin (clb) gene in Escherichia coli is described as a source that could promote carcinogenesis, progressing to colorectal cancer. The present study investigated the demographic, dietary, and antibiotic consumption variables as correlates for fecal carriage of clb+/E coli among the student populace. In a randomized cross-sectional survey, E coli (N = 136) from the fecal samples of eligible students were characterized and evaluated for antibiotic resistance, ß-lactamase (blm), biofilm, virulence factor production, and strain tryptophan reverse mutagenic activity. The encoded clb+/E coli were analyzed for correlates with principal component analysis. Of all the E coli strains, a low rate of 2 clb+/E coli (1.5%) and higher rates of biofilm (13.2%) and blm producers (11.8%) were recorded among the mutant strains as compared with the nonmutant types. All the clb+/E coli showed complete resistance to amoxicillin, Augmentin (amoxicillin and clavulanate), gentamicin, and trimethoprim/sulfamethoxazole. The fecal clb-encoded E coli (1.5%) were not associated with demographic status, fiber-based food (odds ratio [OR], 1.03; 95% CI, 56.74-138.7; P = .213), alcohol (OR, 1.27; 95% CI, 61.74-147.1; P = .221), antibiotic consumptions (OR, 1.11; 95% CI, 61.29-145.3; P = .222), and handwashing (OR, 1.17; 95% CI, 60.19-145.5; P = .216). The hierarchical cluster of blm+/E coli revealed high-level resistance with a multiantibiotic resistance index ≥0.2 (P < .05). Only 12% of all strains were tryptophan mutant/blm+, and 1.5% of clb+/ECblm+ were observed in fecal samples with a 452-base pair size. Trimethoprim/sulfamethoxazole and biofilm production positively regressed with clb expression (P > .05). Principal component analysis score plot indicated an association of clb+/ECblm+ with dietary pattern, alcohol, blm, and hemolysin production. The combined activity of blm and biofilm production in the gut microbiota could promote clb+/E coli colonization, facilitating genotoxin production and possible colorectal cancer induction.

Dataset on rbcL-based intra-specific diversity and population structure of Parkia biglobosa (Jacq.) in Nigeria.

African locust bean (Parkia biglobosa) is a multipurpose leguminous tree species of nutritional and pharmacological value. The plant is widely distributed in Africa and across Nigeria's major agroecological areas (AEAs). Amidst declining cultivation and production, P. biglobosa is genetically threatened in its natural habitats due to overexploitation, deforestation, wildfires and lack of improved tree management practices. Consequently, concerted research efforts directed towards germplasm collection and assessment of genetic relationships are imperative for conserving its genetic resources, sustainable management and selecting promising landraces for breeding programmes. The dataset presents rbcL intraspecific genetic diversity and population structure of 62 P. biglobosa landraces in Nigeria. A relatively high level of diversity and a low degree of nucleotide variability was observed among the landraces. Relatively high values of 642 total allele sites, 601 polymorphic sites, 504 parsimony information sites, 883 total number mutations, 9 haplotypes and 0.55 gene diversity were recorded for the sequence dataset. Low values of 0.35 nucleotide diversity and 5 InDels events were also recorded for the dataset. The gene flow in this dataset demonstrated an extensive exchange of genes between the three populations of P. biglobosa, which influenced the level of genetic differentiation (Gst) between the populations. Significantly low Gst (-0.01) was recorded between the Guinea and Sudan savannah populations, a moderate value (0.03) was recorded between the Sudan savannah and Rainforest populations and a higher Gst value (0.05) was recorded between the Guinea and Rainforest populations. The dataset highlights potential evolutionary dynamics that might influence variations relevant to the breeding and conservation of P. biglobosa in Nigeria and across its range in West and Central Africa.

Nutritional, functional, and bioactive properties of african underutilized legumes.

Globally, legumes are vital constituents of diet and perform critical roles in maintaining well-being owing to the dense nutritional contents and functional properties of their seeds. While much emphasis has been placed on the major grain legumes over the years, the neglected and underutilized legumes (NULs) are gaining significant recognition as probable crops to alleviate malnutrition and give a boost to food security in Africa. Consumption of these underutilized legumes has been associated with several health-promoting benefits and can be utilized as functional foods due to their rich dietary fibers, vitamins, polyunsaturated fatty acids (PUFAs), proteins/essential amino acids, micro-nutrients, and bioactive compounds. Despite the plethora of nutritional benefits, the underutilized legumes have not received much research attention compared to common mainstream grain legumes, thus hindering their adoption and utilization. Consequently, research efforts geared toward improvement, utilization, and incorporation into mainstream agriculture in Africa are more convincing than ever. This work reviews some selected NULs of Africa (Adzuki beans (Vigna angularis), African yam bean (Sphenostylis stenocarpa), Bambara groundnut (Vigna subterranea), Jack bean (Canavalia ensiformis), Kidney bean (Phaseolus vulgaris), Lima bean (Phaseolus lunatus), Marama bean (Tylosema esculentum), Mung bean, (Vigna radiata), Rice bean (Vigna Umbellata), and Winged bean (Psophocarpus tetragonolobus)), and their nutritional, and functional properties. Furthermore, we highlight the prospects and current challenges associated with the utilization of the NULs and discusses the strategies to facilitate their exploitation as not only sources of vital nutrients, but also their integration for the development of cheap and accessible functional foods.

Evaluation of Efflux-Mediated Resistance and Biofilm formation in Virulent Pseudomonas aeruginosa Associated with Healthcare Infections.

Pseudomonas aeruginosa is a significant pathogen identified with healthcare-associated infections. The present study evaluates the role of biofilm and efflux pump activities in influencing high-level resistance in virulent P. aeruginosa strains in clinical infection. Phenotypic resistance in biotyped Pseudomonas aeruginosa (n = 147) from diagnosed disease conditions was classified based on multiple antibiotic resistance (MAR) indices and analysed with logistic regression for risk factors. Efflux pump activity, biofilm formation, and virulence factors were analysed for optimal association in Pseudomonas infection using receiver operation characteristics (ROC). Age-specificity (OR [CI] = 0.986 [0.946-1.027]), gender (OR [CI] = 1.44 [0.211-9.827]) and infection sources (OR [CI] = 0.860 [0.438-1.688]) were risk variables for multidrug resistance (MDR)-P. aeruginosa infection (p < 0.05). Biofilm formers caused 48.2% and 18.5% otorrhea and wound infections (95% CI = 0.820-1.032; p = 0.001) respectively and more than 30% multidrug resistance (MDR) strains demonstrated high-level efflux pump activity (95% CI = 0.762-1.016; p = 0.001), protease (95% CI = 0.112-0.480; p = 0.003), lipase (95% CI = 0.143-0.523; p = 0.001), and hemolysin (95% CI = 1.109-1.780; p = 0.001). Resistance relatedness of more than 80% and 60% to cell wall biosynthesis inhibitors (ceftazidime, ceffproxil, augumentin, ampicillin) and, DNA translational and transcriptional inhibitors (gentamicin, ciprofloxacin, ofloxacin, nitrofurantoin) were observed (p < 0.05). Strong efflux correlation (r = 0.85, p = 0.034) with MDR strains, with high predictive performances in efflux pump activity (ROC-AUC 0.78), biofilm formation (ROC-AUC 0.520), and virulence hierarchical-clustering. Combine activities of the expressed efflux pump and biofilm formation in MDR-P. aeruginosa pose risk to clinical management and infection control.

Functional bioactive compounds in ginger, turmeric, and garlic.

Nutrition plays a very important role in the health promotion of individuals and brought about a global paradigm shift from pharmaceuticals to nutraceuticals. This is due to the high cost, non-availability, and side effects associated with the unregulated consumption of pharmaceuticals. Over the ages, nutraceuticals from food products were reported to contain bioactive compounds with great health and physiological benefits. This report reviews bioactive compounds in selected foods namely ginger (Zingiber officinale), turmeric (Curcuma longa), and garlic (Allium sativum) as potential natural therapeutics for ailments of cancer and heart-related diseases. Analytical profiles, functional activities, and characterization of these compounds were discussed with possible recommendations for the prospective treatment of diseases using these nutraceuticals.

Emerging vancomycin-non susceptible coagulase negative Staphylococci associated with skin and soft tissue infections.

BACKGROUNDS: Observable emergence of Vancomycin-Non susceptible Coagulase-negative Staphylococci (VNS-CoNS) associated with skin and soft tissue infections spreading among the urban and rural populace is gradually intensifying severe complications. The isolated VNS-CoNS were evaluated with Matrix-assisted Laser Desorption/ionization Time of Flight Mass Spectrometry (MALDI ToF MS) for species characterization and pan-antimicrobial resistance pattern. METHODS: Out of 256 clinical samples collected including pus, abscess, ear swabs, eye swabs, and aspirates, 91 CoNS isolates were biotyped and further characterized with MALDI-TOF MS. Staphylococci marker genes, Vancomycin susceptibility, and biofilm assays were performed. RESULTS: Of 91 CoNS isolates, S.cohnii (2.3%), S.condimentii (3.4%), S. saprophyticus (6.7%), and S.scuri (21.1%) were characterized with MALDI-TOF with significant detection rate (99.4%; CI 95, 0.775-0.997, positive predictive values, 90.2%) compared to lower biotyping detection rate (p = 0.001). Hemolytic VNS-CoNS lacked nuc, pvl and spa genes from wound, ear, and aspirates of more 0.83 MARI clustered into a separate phylo-diverse group and were widely distributed in urban and peri-urban locations. MALDI TOF-MS yielded a high discriminatory potential of AUC-ROC score of 0.963 with true-positivity prediction. VNS-CoNS of MIC ≥ 16 µg/mL were observed among all the ages with significant resistance at 25th and 75th quartiles. More than 10.5% of CoNS expressed multi-antibiotic resistance with more than 8 µg/mL vancomycin cut-off values (p < 0.05). CONCLUSION: Antibiotic resistant CoNS should be considered significant pathogens rather than contaminant. Biofilm producing VNS-S. sciuri and S. condimentii are potential strains with high pathological tropism for skin, soft tissues and wound infections, and these strains require urgent surveillance in peri-urban and rural communities.

African fermented foods: overview, emerging benefits, and novel approaches to microbiome profiling.

Traditional fermented foods are of major importance with respect to the socio-economic growth, food security, nutrition, and health of African consumers. In several African countries, traditional fermentation processes provide a means of food preservation, improving the shelf life and adding to the nutrients in the food products. As with any fermented foods, the associated food microbiota is of great importance and interest. Recent studies on the microbiome of African fermented foods using high-throughput DNA sequencing techniques have revealed the presence of diverse microbial populations of fundamental, technological, and commercial interest that could be harnessed to further improve health, food safety, and quality. This review provides an overview of African fermented foods, their microbiota, and the health-promoting potential of these foods and microbes.

Evolution and genetic diversity of SARS-CoV-2 in Africa using whole genome sequences.

BACKGROUND: The ongoing SARS-CoV-2 pandemic was introduced into Africa on 14th February 2020 and has rapidly spread across the continent causing a severe public health crisis and mortality. We investigated the genetic diversity and evolution of this virus during the early outbreak months, between 14th February to 24th April 2020, using whole genome sequences. METHODS: We performed recombination analysis against closely related CoV strains, Bayesian time scaled phylogeny, and investigation of spike protein amino acid mutations. RESULTS: Recombination signals were observed between the Afr-SARS-CoV-2 sequences and reference sequences within the RdRPs and S genes. The evolutionary rate of the Afr-SARS-CoV-2 was 4.133 × 10-4 Highest Posterior Density (HPD 4.132 × 10-4 to 4.134 × 10-4) substitutions/site/year. The time to most recent common ancestor (TMRCA) of the African strains was December 7th 2019, (95% HPD November 12th 2019-December 29th 2019). The Afr-SARCoV-2 sequences diversified into two lineages A and B, with B being more diverse with multiple sub-lineages confirmed by both maximum clade credibility (MCC) tree and PANGOLIN software. There was a high prevalence of the D614G spike protein amino acid mutation 59/69 (82.61%) among the African strains. CONCLUSION: This study has revealed a rapidly diversifying viral population with the G614G spike protein variant dominatinge advocate for up scaling NGS sequencing platforms across Africa to enhance surveillance and aid control effort of SARS-CoV-2 in Africa.

Evolutionary dynamics and geographic dispersal of beta coronaviruses in African bats.

Bats have been shown to serve as reservoir host of various viral agents including coronaviruses. They have also been associated with the novel coronavirus SARS-CoV-2. This has made them an all important agent for CoV evolution and transmission. Our objective in this study was to investigate the dispersal, phylogenomics and evolution of betacoronavirus (ßCoV) among African bats. We retrieved sequence data from established databases such as GenBank and Virus Pathogen Resource, covering the partial RNA dependent RNA polymerase (RdRP) gene of bat coronaviruses from eight African, three Asian, five European, two South American countries and Australia. We analyzed for phylogeographic information relating to genetic diversity and evolutionary dynamics. Our study revealed that majority of the African strains fell within Norbecovirus subgenera, with an evolutionary rate of 1.301 × 10-3, HPD (1.064 × 10-3-1.434 × 10-3) subs/site/year. The African strains diversified into three main subgenera, Norbecovirus, Hibecovirus and Merbecovirus. The time to most common recent ancestor for Norbecovirus strains was 1973, and 2007, for the African Merbecovirus strains. There was evidence of inter species transmission of Norbecovirus among bats in Cameroun and DRC. Phlylogeography showed that there were inter-continental spread of Bt-CoV from Europe, China and Hong Kong into Central and Southern Africa, highlighting the possibility of long distance transmission. Our study has elucidated the possible evolutionary origins of ßCoV among African bats; we therefore advocate for broader studies of whole genome sequences of BtCoV to further understand the drivers for their emergence and zoonotic spillovers into human population.

Principal Components and Hierarchical Cluster Analyses of Trace Metals and Total Hydrocarbons in Gills, Intestines and Muscles of Clarias gariepinus (Burchell, 1822).

The aim of the study was to comparatively analyze the interrelationships among iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and total hydrocarbons (THCs) in the gills, intestines and muscles of Clarias gariepinus collected from Osse River, Nigeria, between the periods of April, 2013 to September, 2014. The trace metals in the fish tissues were analyzed using Atomic Absorption Spectrophotometer (AAS, Philips model PU 9100), while total hydrocarbons were analyzed using High Performance Liquid Chromatograph (HPLC,Prominence Dual brand from HGE) equipped with a detector Shimadzu UV-Visible (UV-Vis Prominence SPD 20 A). The concentrations of trace metals and THCs in the tissues were subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), backed up by correlation analysis (CA). In the most prioritized component among the hierarchies of contaminants, characterized as principal component 1, results of communality extractions and rotated component matrices revealed the order of contaminants was Mn > Cu > Zn > Fe > Cr in the intestines, Cr > Cu > THCs > Mn > Fe in the muscle, while Pb > Cr > Fe > Mn was the order in the gills of the fish. Iron inhibited accumulation of the other trace metals in the gills, where its threshold of essentiality was maximal. Noteworthy is the fact that Mn and Cu were the most active components in the muscle and concurrently of excess concentrations in the tissue, which is the major edible part of fish, and constitutes its main body weight, hence holds its nutritional and economic values. High level of variability which occurred in the toxicant profile across the tissues of C. gariepinus is a function of uptake route, varied organ functions and specificity of tissue permeability of the compared organs. The study demonstrated variability in organ accumulation capacity and toxicant's competitiveness irrespective of bioavailability. The study provides data useful for future ecotoxicological studies and safety of consumers of the fish.

Antimicrobial resistance pattern and virulence profile of S. aureus isolated from household cattle and buffalo with mastitis in Egypt.

Methicillin resistant S. aureus from cows with mastitis has received a growing interest worldwide. The present study aimed to provide a detailed description of the resistance and virulence traits of isolates from bovine mastitis samples. A total of 550 quarter milk samples were collected from 140 mastitic household dairy cows and buffalo from five herds at Dakahlia Governorate, Egypt, during 2017 and 2018. Staphylococcus spp. were isolated and differentiated using MALDI-TOF MS. A genotypic characterization was performed for S. aureus isolates using DNA-microarray and staphylococcal protein A (spa) typing. Furthermore, antibiotic resistances were phenotypically confirmed using broth microdilution. Six different clonal lineages (CC1-MRSA, CC5-MRSA, CC45-MRSA, CC97-MSSA, CC50-MSSA and CC1153-MSSA), including seven spa types (t127, t688, t132, t267, t521, t224 and t903) were identified. Spa type t267 was the most dominant among the investigated herds. This is the first report of the occurrence of clonal lineages CC97, CC1, CC45, CC50 and CC1153 from bovine mastitis in Egypt. All MRSA isolates and 33.3 % of MSSA were multi-resistant (i.e. resistant to more than three classes of compounds). Various virulence determinants were also observed including leukocidins, hemolysins, and enterotoxins. The study demonstrates a low diversity of S. aureus isolates recovered from several dairy herds. The findings of the observed virulotypes can be useful for future studies on anti-virulence therapies, immunogenicity and vaccine development.

Phylo-diversity of prevalent human E. coli O157:H7 with strains from retailed meat and fish in selected markets in Ibadan Nigeria.

Global prevalence of ESBL-biotypes poses a serious threat to public health as a result of severity and morbidity caused by beta-lactam encoded Escherichia coli. Therefore, the prevalent shiga toxigenic Escherichia coli of ESBL variant was investigated in various retailed food animals and cooking materials. A total of 823 samples consisting of raw meat (297) and fish (132) samples retailed at various major markets in Ibadan were collected and 394 swabs were taken from the butchers' processing tables and utensils used in retailing meat and fish. The samples were cultured and biotyped for Escherichia coli. Serological and PCR assay were used to identify O157:H7 variant and antibiotics resistant determinants. Genetic relatedness of characterized E. coli O157 from human and meat products was evaluated with phylogenetic analysis. Of all the isolates, 130 (15.8%) were E. coli and only 8 (1.0) were O157:H7 while 4 (50%) were resistant to one or more antibiotics with resistance index ranging from 0.1 to 0.5. More than 25% E. coli O157:H7 were resistant to Ampicillin, Pefloxacin and Gentamicin and blaSHV and blaCTX-M were detected in 1/8 (12.5%) of E. coli O157:H7 and blaTEM 3/8 (37.5%) respectively. Only 1 genotyped human Escherichia coli .0157:H7 clustered with beef strain There is evidence of blaTEM encoded E. coli O157:H7 causing infection in human from food animals retailed in many markets within various communities. Therefore, urgent surveillance with public health education, food, and environmental hygiene are highly needed to prevent its spread.

In Silico Screening and Analysis of Broad-Spectrum Molecular Targets and Lead Compounds for Diarrhea Therapy.

Diarrhoeal disease kills about 1.5 million human beings per year across the continents. The enterotoxigenic Escherichia coli (ETEC) pathotype has been noted as a major cause of diarrheal disease in human and livestock. The aim of this study is to identify broad-spectrum molecular targets in bacteria and broad-spectrum lead compounds (functional inhibitors) with high efficacy and no significant adverse implication on human systems, in relevance to diarrhea therapy through computational approaches which include phylogenetics, target prediction, molecular docking, and molecular flexibility dynamic simulations. Three molecular target genes, murA, dxr, and DnaE, which code for uridine diphosphate-N-acetylglucosamine-1-carboxyvinyltransferase, 1-deoxy-D-xylulose-5-phosphate reductoisomerase, and deoxyribonucleic acid polymerase III alpha subunit, respectively, were found to be highly conserved in 7 diarrhea-causing microbes. In addition, 21 potential compounds identified showed varied degree of affinity to these enzymes. At free energy cutoff of -8.0 kcal/mol, the highest effective molecular target was DNA polymerase III alpha subunit (PDB ID: 4JOM) followed by UDP-N-acetylglucosamine-1-carboxyvinyltransferase (PDB ID: 5UJS), and 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PDB ID: 1ONN), while the highest effective lead compound was N-coeleneterazine followed by amphotericin B, MMV010576, MMV687800, MMV028694, azithromycin, and diphenoxylate. The flexibility dynamics of DNA polymerase III alpha subunit unraveled the atomic fluctuation which potentially implicated Asp593 as unstable active site amino acid residue. In conclusion, bacteria DnaE gene or its protein is a highly promising molecular target for the next generation of antibacterial drugs of the class of N-coeleneterazine.

Fecal carriage and phylodiversity of community-acquired bla TEM Enteric bacilli in Southwest Nigeria.

PURPOSE: Increasing rates of clonal spread of fecal blaTEM bacilli remains a huge concern to the community health with resultant high morbidity. The fecal carriage and clonal diversity of bla TEM within the communities in Southwest Nigeria were surveyed. MATERIALS AND METHODS: Enteric bacilli obtained from fresh fecal samples randomly collected from community residents were biotyped and profiled for antibiotic susceptibility. Resistant strains were typed for beta-lactamase, extended-spectrum beta-lactamases (ESBL), AmpC and carbapenemase production while the R-plasmid carriage was detected and mating activities were examined. The presence of bla TEM gene was assayed by PCR and its phylodiversity determined with 16sRNA genomic profiling. RESULTS: Escherichia coli have the highest (28.6%) occurrence rate and Pseudomonas aeruginosa (20.5%) showing significant resistance to beta-lactamase inhibitors (ampicillin, cefuroxime and cefotaxime), and high-level multidrug resistance of more than 15.2% rate to ampicillin, cefuroxime, ceftazidime, tetracycline and imipenem. E. coli and Klebsiella oxytoca, are the highest beta-lactamase, ESBL and AmpC producers encoded with high molecular weight R-plasmid (>11.0 kbp) and significant rate of conjugation and transformational activities. Only 2/14, 1/13 and 1/6 ESBL-type of E. coli, K. oxytoca and Enterobacter cloaca, expressed bla TEM gene, clustering into five different phylodiverse groups with close genomic relatedness with other bacilli. CONCLUSION: This is an indication of clonal dissemination of ESBL bla TEM encoded enteric bacilli having high phylodiverse characteristics through fecal carriage in the Nigerian community which requires public health education, food and environmental hygiene for its prevention.

Motile Salmonella serotypes causing high mortality in poultry farms in three South-Western States of Nigeria.

This study was carried out to identify the Salmonella serotypes causing high mortality in chickens in Lagos, Ogun and Oyo states, Nigeria. Chickens presented for postmortem examination during disease outbreaks that were characterised by high mortality (40 per cent to 80 per cent) in poultry farms in the study area were examined from January to December, 2013. Samples of the lungs, heart, liver, spleen, kidneys, proventriculus, intestine and caecum were collected from suspected cases of salmonellosis, for bacterial culture and identification. Salmonella isolates were confirmed using PCR and serotyped using the Kauffman-White scheme. Twenty-six day-old pullets were raised to two weeks and inoculated orally with 0.2 mL of 1×108 colony forming units of Salmonella Zega identified in the present study to determine their pathogenicity, while another 26 served as control. The Salmonella serotypes were S Zega (n=13; 35.14 per cent), Salmonella Kentucky (n=9; 24.32 per cent), Salmonella Herston (n=6; 16.22 per cent), Salmonella Nima (n=4; 10.81 per cent), Salmonella Telelkebir (n=3; 8.11 per cent), Salmonella Colindale (n=1; 2.70 per cent) and Salmonella Tshiongwe (n=1; 2.70 per cent). Clinical signs in both natural and experimental infections were acute (70 per cent) and chronic (30 per cent), and included weakness, anorexia, yellowish diarrhoea, pasted vents, somnolescence and mortality, while gross lesions showed marked pulmonary congestion and oedema, necrotic foci in the myocardium; the liver, spleen and kidneys were markedly enlarged and had subcapsular multifocal necrosis. There were catarrhal proventriculitis and enteritis, and haemorrhagic typhlitis. While most of the serotypes identified in the present study have been isolated from poultry sources from commercial farms in Nigeria, to the best of the authors' knowledge, they have not been previously reported to cause high mortality in chickens in the study area.

High-level Multi-Resistant and Virulent Escherichia coli in Abeokuta, Nigeria.

Multi-resistant Escherichia coli (E. coli) strains co-harboring virulence genes is a cause of high morbidity in Abeokuta, Nigeria. This study was designed to determine some virulent factors among enteropathogenic E. coli in Abeokuta, Nigeria. Approximately non-repetitive 102 isolates of E. coli were recovered from clinical samples from two health facilities in Abeokuta. Biotyping using API and antibiotic susceptibility was determined, and eae and flic genes were assayed by PCR. Antibiotic resistance relatedness was performed by DendroUPGMA. Results showed that 48.0% and 52.0 % were intestinal and extra-intestinal E. coli, ampicillin recorded 100% resistance, amoxycilli/clavulanic acid 64.7%, cotrimoxazole 57.8% and 56.8% resistance against cefotaxime, at MIC >16 ug/mL, 100%, 57.8%, and 50% have MIC50 to ampicillin, tetracycline, and ceftazidime, while 74.5% and 48.0% have MIC90 to ampicillin and ceftazidime. Significant rates of 4.9%, 7.8%, and 9.8% flic, eae, and flic/eae genes were found in intestinal isolates, while 2.9%, 2.0%, and 3.9% were found in extra-intestinal (P < 0.05). Two major clades of the resistant isolates reveal significant antibiotic relatedness among intestinal and extra-intestinal isolates, at 54% resistance similarities with very high multi-antibiotic resistance index of 1.0 (MARI). A high rate of undetected virulent E. coli pathotypes with high resistance could trigger unprecedented morbidity and mortality, mostly among children and the elderly.

Genotypes and phenotypes of Shiga toxin-producing Escherichia coli (STEC) in Abeokuta, Southwestern Nigeria.

PURPOSE: To characterize the prevalence of hemolytic Shiga toxin-producing Escherichia coli (STEC) with a multidrug-resistant pattern in different age groups in Abeokuta, Nigeria. METHODS: Nonrepetitive E. coli isolates were collected from 202 subjects with or without evidence of diarrhea. Each isolate was biochemically identified and antimicrobial susceptibility testing was performed using the disk diffusion method. A sorbitol fermentation test of all the E. coli isolates was done and the minimum inhibitory concentration of suspected STEC was measured by the standard broth microdilution method to determine antibiotic resistance. The genotypes of stx1, stx2, and hlyA were determined by polymerase chain reaction assay. RESULTS: The majority of subjects were aged ≥40 years (41.6%) and were female (61.9%). Of the 202 subjects, 86.1% had STEC isolates (P<0.05). A high rate of STEC isolates resistant to amoxicillin (90.6%), cefotaxime (77.7%), and cefuroxime (75.7%) was observed. Resistance to amoxicillin, gentamicin, and cefotaxime was demonstrated with a minimum inhibitory concentration >16 µg/mL in 13.9%, 11.4%, and 10.4% of the isolates, respectively. The prevalence of stx1, stx2, and hlyA was 13.9%, 6.9%, and 2.0%, respectively; 5.5% of stx1 were in the 0-10-year-old age group, 3.5% of stx2 were aged ≥40 and above, and 1.0% of the hlyA isolates were in the 0-10-year-old age group. CONCLUSION: The prevalence of virulent STEC is a public health concern. The use of polymerase chain reaction assay should aid quick detection of this virulent serotype and help curb the severe epidemic of human diseases associated with STEC infections.

Comparative evaluation of haemagglutination potential of haemolymph from two species of giant African land snails (Archachatina marginata and Achatina achatina).

A comparative study was conducted to evaluate haemagglutination potential in the haemolymph of two species of giant African land snails (Archachatina marginata and Achatina achatina). Three liveweight groups of snails (<100 g, 101-150 g and >150 g) were used with 4 replicates per liveweight per species for haemagglutination assay (HA). The effect of aestivation on haemagglutination potential was also evaluated. Erythrocytes (2%) from cattle, sheep, goat and chicken were used for HA assay. Results showed that agglutinin-like substances that agglutinate erythrocytes of sheep, goat, cattle and chicken were present in the haemolymph of the two species of giant African land snails. Effect of species was found to be significant (P < 0.001) on haemagglutination titre. Haemolymph of A. marginata, had higher haemagglutination titre than that of A. achatina across the three liveweight groups used in this study. Snail liveweight had no significant effect (P > 0.05) on agglutinin content of the haemolymph in both species. Agglutination level depended on the source of erythrocyte used. Sheep erythrocyte recorded the highest haemagglutination titre, followed by goat, cattle, and chicken in that order. To our knowledge, this is the first evidence that Giant African land snails (GALS) haemolymph contain agglutinins as previously reported for Helix species. This evidence may be the basis for its survivability in the wild and thus establish the use of GALS for African herbal medicinal applications.