Shiga Toxin and Non-Shiga Toxin-Producing Escherichia coli O157 from Cattle, Goats and Chickenin Ado-Ekiti, South West, Nigeria.

Background: Illnesses due to contaminated food, particularly food of animal origin, are perhaps the most widespread health problem in the contemporary world. Aims: To detect Shiga toxin-producing Escherichia coli (STEC) in food animals in Ado-Ekiti, Nigeria and the possible risk to human health. Study Design: Non-repeat faecal samples from various animals and poultry birds were examined for STEC. Place and Duration of Study: Department of Microbiology, Ekiti State University, Ado-Ekiti, between January 2010 and December 2011. Methodology: We investigated 722 non-repeat faecal samples from animals and poultry birds for the presence of STEC using bacteriological, serological, and tissue culture techniques. Detection of virulence genes was performed by PCR. Results: Overall, 316 isolates of E. coli were recovered from 62.3% cattle, 19.6% local chicken, 10.1% goats, 4.1% broiler, 2.9% layers, and 0.9% cockerels. Of the non-sorbitol fermenting E. coli phenotype selected from the isolates, 13.3% were presumptively identified as O157 serotype based on inability to ferment sorbitol on sorbitol MacConkey agar (SMAC). Serotyping using commercial kits capable of detecting O157 and non-O157STEC confirmed 6.6% of these as O157 comprising 4.1% from cattle and 2.5% from local chicken. Only 4.7% of the strains were serologically confirmed as non-O157 of which 0.9% was from cattle, 3.2% from goat and 0.6% from local chicken. Verocytotoxicity test and the presence of virulence genes stx1, stx2 and eae assayed by PCR showed the complete absence of virulence genes in the 13 serologically confirmed strains of O157 from cattle. The virulence gene stx1 was detected only in non-O157 strain from goat and local chickens. Conclusion: This study has shown that the prevalence of E. coli O157 is low in food animals in the study area compared to reports from the developed countries. Furthermore, our study is the first to report the isolation of non-O157STEC in goat, a very common domestic animal, in the study area.

Plasmid and Restriction Endonuclease Analyses of Bacteria Associated with Pneumonia in HIV/AIDS Patients in Ekiti State, Nigeria.

Bacterial infections are an important cause of morbidity and mortality in individuals with the human immunodeficiency virus. The emergence of multiple-drug resistant bacteria has been documented by many researches. This study was therefore carried out to determine whether the resistances of bacterial isolates from HIV positive and HIV negative patients are plasmid mediated or chromosomal mediated. The Plasmid, Post Plasmid-curing Sensitivity and Restriction enzymes endonuclease were done using standard methods. The result of plasmid analysis showed that Plasmid-mediated resistance was observed in both populations and the molecular weight of the plasmid DNA was 1000 base pairs. Plasmid mediated resistance was common, and this was observed in all isolates from HIV/AIDS patients with exceptions of P. aeruginosa in which the resistance was chromosomally mediated. Restriction endonuclease analysis from E. coli revealed 3 distinct clusters. The result of restriction enzymes analysis indicate that the pneumonia infection in HIV/AIDS patients is likely to be hospital acquired in the study location. The study also suggests a common source of infection of the patients.

Antibacterial Effect of Some Nigerian Medicinal Plants on Drug-Resistant Salmonella Species Isolated from Enviromental Sources

Sensitivity of Salmonella species isolated from different environmental sources to the extracts of Azadirachita indica; Psdium guajava; Kigelia africana and Aloe microcarpa was investigated. Susceptiblity of the isolates to amoxicillin; ofloxacin; tetracycline; gentamicin; nalixidic acid; nitrofuratoin and cotrimoxazone was also examined. The sensitivity assay was done using agar dilution technique at concentrations ranging from 0.5 to 20v/v. The concentration of all the extracts of the experimental plants that inhibited the growth of Salmonella species ranged from 10 to 20v/v with minimum inhibitory concentration of 5.0v/v. All the extracts at concentration of 20v/v exhibited 100growth inhibition on Salmonella isolates. All the isolates exhibited resistance patterns ranging from 50 to 100against the antibiotics examined. Anti-nutrients constituents detected in all the plants materials were alkaloids (1.29-3.57); tannins (4.69-6.33); saponins (2.45-7.57); phenols (0.26- 0.60) and Flavonoids 0.41-1.00. The need to source for anti-typhoidal drugs from medicinal plants is discussed