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

Microbiological studies of cockroaches from three localities in Gaborone, Botswana

Cockroaches have become the most common pests in a majority of households in Gaborone, the capital city of Botswana Their presence has always raised safety concerns, especially as carriers of food-borne pathogens and food-spoilage organisms. To address the safety issues, bacteriological investigations were carried out on cockroaches trapped from the kitchens and toilets of three localities in Gaborone, households in Botswana. The bacterial, total spore forming, Bacillus cereus, coliforms and E. coli counts from the surfaces of cockroaches were estimated using bacteriological media. Aerobic and facultatively anaerobic bacteria from the fecal pellets were isolated and characterized. Specialized mediawere used for culturing pathogens. 67 %, 22.2 % and 28.6 % of the cockroaches trapped in the kitchen from Central/Broadhurst, Old Naledi and Tlokweng, respectively, had aerobic plate counts of > 106 CFU/cockroach. The cockroaches trapped from the toilets had higher counts than kitchens. Sporeformers were present in most samples though in lower numbers. However, Bacillus cereus was only found in some of the cockroaches at much lower numbers. As much as 70– 98.3% of the cockroaches had coliforms; but, E. coli was only found in 5–6.5% of the cockroaches at > 103 CFU/cockroach. 70 species of bacteria representing 37 genera were isolated from the surface and fecal pellets. Even though the majority of the bacteria that were isolated from the surfaces were Gram negative thosefrom the pellets were mostly Gram positive. The most common and abundant species belonged to Pseudomonas and Serratia, with members of the Enterobacteriaceae following. In the pellets, species of Bacillus were predominant, but, there were some members of Enterobacteriaceae. Pathogens like Salmonella, Shigella and B. cereus were isolated. Opportunistic pathogens like species of Pseudomonas, Klebsiella and Vibrio and food spoilage bacteria such as species of Enterobacter, Citrobacter, Escherichia, Erwinia, and Pseudomonas were also found. Proper care in disposal of food remnants and overall cleanliness at the householdsprevents cockroaches from foraging in the kitchen and toilet

Prevalence of rotavirus, adenovirus and astrovirus infection in young children with gastroenteritis in Gaborone, Botswana

Objective: To determine the prevalence of three enteric viruses, namely rotavirus, adenovirus and astrovirus, as agents of diarrhoea in and around Gaborone, Botswana. Design: The sample were categorised into four groups according to the age of the patient: 0-3 months, 4-6 months, 7-12 months and 25-60 months. Total monthly samples across age groups formed basis for calcultating seasonal prevalence of rotavirus infection. Setting: Stool samples were collected from three medical laboratories in Gaborone and one in the town of Mochudi. These were collected from children under the age of five years with gastroenteritis. Subjects: Stool samples were collected between March 2001 and February 2002 from 346 children less than five years of age suffering from gastroenteritis. These samples had been sent to medical laboratories for microbiological examination. Methods: The samples were screened for rotavirus (RV), adenovirus (Ad) and astrovirus (AsV) antigens using commercially available ELISA kits. The Ad positive samples were further analysed by commercially available group specific Ad type 40/41 Enzyme Immuno Assays (EIA). Results: Shedding of RV was detected in 9.2%, Ad in 7.8% and AsV in 2.7% of the samples analysed. The enteric Ad (types 40 and 41) were detected in 2% of the samples and the remaining 5.8% of Ad positive samples were non-enteric Ad. An increase of RV was noted in the autumn-winter season but no seasonal pattern was observed in Ad shedding. Seasonal prevalence of AsV could not be determined. The average age of children infected with these agents was less than one year. Conclusion: The incidence of rotavirus infection amongst children in Botswana appears to be relatively low. The prevalence rate of adenovirus and astrovirus is similar to other studies in parts of Southern Africa. However, continued enteric virus surveillance and epidemiology amongst this group is required. East African Medical Journal Vol.80(12) 2003: 652-65