Prevalence, antimicrobial resistance profiles of Listeria monocytognes from various foods in Gaborone, Botswana

Listeria monocytogenes is known to cause epidemic and sporadic cases of listeriosis. The present study investigated the occurrence, antibiograms and molecular serotypes of the organism in various retail outlets in Gaborone, Botswana. Food samples were obtained randomly from selectedsupermarkets and street vendors in 5 geographical areas of Gaborone from May, 2007 to September 2007. L. monocytogenes was isolated and positively identified by using morphological and biochemical tests. From a total of 1324 food samples tested 57(4.3 %) were positive for L. monocytogenes. Out of the 57 isolates of L. monocytogenes 7 (12.3%), 3 (5.3%), 0 (0%), 27 (47.4%) and 20 (35.1%) were isolated from cheese, raw milk, meat (biltong), frozen cabbage and salad (coleslaw), respectively. From the 5 geographical areas selected for sampling in this study, Gaborone South recorded the highest number 19 (33.3%) of L. monocytogenes isolates while Gaborone West recorded the least, 7 (12.3%). The findings in this study reveal the presence of L. monocytogenes serotypes 1/2a and 1/2b in ready to eat food and highlight the need for education and training programmes in food safety in Gaborone, Botswana

Investigation of the Enteric Pathogenic Potential of Oral Campylobacter concisus Strains Isolated from Patients with Inflammatory Bowel Disease

BACKGROUND: Campylobacter concisus, a bacterium colonizing the human oral cavity, has been shown to be associated with inflammatory bowel disease (IBD). This study investigated if patients with IBD are colonized with specific oral C. concisus strains that have potential to cause enteric diseases. METHODOLOGY: Seventy oral and enteric C. concisus isolates obtained from eight patients with IBD and six controls were examined for housekeeping genes by multilocus sequence typing (MLST), Caco2 cell invasion by gentamicin-protection-assay, protein analysis by mass spectrometry and SDS-PAGE, and morphology by scanning electron microscopy. The whole genome sequenced C. concisus strain 13826 which was isolated from an individual with bloody diarrhea was included in MLST analysis. PRINCIPAL FINDINGS: MLST analysis showed that 87.5% of individuals whose C. concisus belonged to Cluster I had inflammatory enteric diseases (six IBD and one with bloody diarrhea), which was significantly higher than that in the remaining individuals (28.6%) (P<0.05). Enteric invasive C. concisus (EICC) oral strain was detected in 50% of patients with IBD and none of the controls. All EICC strains were in Cluster 1. The C. concisus strain colonizing intestinal tissues of patient No. 1 was closely related to the oral C. concisus strain from patient No. 6 and had gene recombination with the patient's own oral C. concisus. The oral and intestinal C. concisus strains of patient No. 3 were the same strain. Some individuals were colonized with multiple oral C. concisus strains that have undergone natural recombination. CONCLUSIONS: This study provides the first evidence that patients with IBD are colonized with specific oral C. concisus strains, with some being EICC strains. C. concisus colonizing intestinal tissues of patients with IBD at least in some instances results from an endogenous colonization of the patient's oral C. concisus and that C. concisus strains undergo natural recombination

Detection and molecular characterisation of Group A rotavirus from children in northern Botswana

Objectives: To determine the presence of group A rotavirus in human stool samples in northern Botswana and to characterise the circulating strains. Design: A cross sectional study. Setting: The University of Botswana and Botswana-Havard Partnership for HIV Research. Subjects: A total of 210 stool samples was collected; 104 from hospitalised and 106 from non-hospitalised children, five years and below suffering from gastroenteritis. Results: Out of 210 diarrhoea stool samples collected, 27 (13%) tested positive for group A rotavirus. There was a higher prevalence of infection in hospitalised children (63%) as compared to the non-hospitalised ones (37%). Most rotavirus infections occurred in the age 24 months and below. Of the 13 samples which were positive by PAGE, the predominant electrophoretic pattern detected was the short (S) electrophoretype 9/13 (69%) followed by the long (L) electrophoretype 4/13 (31%). The following G types were detected; G2 (17%), G3 (22%). mixed infections found were G1+G2 (5.6%), G1+G8 (22%), G3+G9 (27.8%) and G1+G3+G9 (5.6%). P[6] was the only VP 4 genotype detected. Rotavirus strains G3P[6] and G3+G9P[6] were identified as the circulating strains in north Botswana. Conclusion: The detection of uncommon rotavirus strains and the high proportion of mixed infections suggest a greater diversity of rotavirus infections among children in Botswana than previously reported. Our study reveals a complex epidemiological profile of rotavirus infection in Botswana that may require further molecular characterisation. East African Medical Journal Vol.82(4) 2005:203-20

The Family Campylobacteraceae

The Campylobacteraceae is the largest and most diverse family in the phylogenetically distinct Epsilonproteobacteria, presently comprising the genera Campylobacter (30 taxa), Arcobacter (17 taxa), and Sulfurospirillum (7 taxa). Individual species may be able to grow in microaerobic, anaerobic, and/or aerobic conditions, in temperatures from 25°C to 42°C; free-living, commensal, or pathogenic; motile or aflagellate; and able to colonize the oral cavity, intestine, stomach, or reproductive tracts of humans, large production animals (such as sheep, cattle, and deer), birds, and reptiles. Some species are known to be among the most frequent causes of human gastroenteritis, others are significant threats to bovine and ovine fertility, and many pose an as-yet unknown, or no, role in human or animal diseases. The taxonomy of the Campylobacteraceae has evolved extensively since its beginnings in 1963. This chapter outlines key events in the family's taxonomic history; reviews general phenotypic traits of each genus, including their isolation; outlines the clinical (including pathogenicity studies and antimicrobial resistance traits) and/or ecological significance of constituent species; and describes current approaches and challenges for species identification and epidemiological subtyping