Bacteria associated with street vended foods: implications to food quality and safety

Street vended foods were analysed for the bacterial load and the presence of pathogenic and/or potentially pathogenic bacteria. The foods were collected randomly from ambulatory and stationary vendors and analysed individually and then categorized as meats, salads and carbohydrates. The microbial analysis indicated that the foods that were served by ambulatory vendors had higher microbial load than those that were served from stationary ones. The salads were also found to contain high microbial load than other food types. The food was also contaminated with coliforms of fecal origin. E. coli was isolated from some food and it occurred in low counts as the highest count was 2.0 log10 CFU/g. The pathogens isolated from the foods were B. cereus, Listeria species, and S. aureus. No Salmonella or Enterococci were recovered from the food. Generally, the microbiology of the street foods was of acceptable quality, with the exception of the salads, and the results better than that of foods reported in other studies. This was despite the fact that most of the vendors operated under seemingly unsanitary conditions.Keywords: Street foods, safety, aerobic plate count, fecal coliforms, pathogens, ambulatory, station

Klebsiella pneumoniae: A potential food safety risk in wild fruits and dried vegetables in Botswana

The bacterium Klebsiella pneumoniae is ubiquitous in nature and is found on the general vegetation and their fruits. The subspecies “pneumonia” is known to cause community-acquired and nosocomial pneumonia in immune-compromised persons (Ko et al., 2002; Yu et al., 2007; Yinnon et al., 1996 and Struve and Krogfelt, 2004). Some the vegetation and wild fruits form part of the staple diet or is consumed as delicacies in Botswana. The potential presence of K. pneumoniae therefore poses a potential food safety hazard given the fact that the gastro-intestinal route is considered one of the major infection routes of K. pneumoniae (Struve and Krogfelt, 2004 and Struve and Krogfelt, 2003). This study sought to evaluate the occurrence of K. pneumoniae in dried vegetables and fruits consumed in Botswana. One representative dried vegetable (morogo wa dinawa) and two representative wild fruits (morula and moretlwa) were selected for the study based on their popularity in the country. The study confirmed the occurrence of K. pneuminioniae on the three foods studied. The isolation rates of the microbe per sample type was 92.3% (morula fruit), 86.4% (morogo wa dinawa) and 86.2 (moretlwa). The overall isolation rate from the three sample types was 89.3%. This showed that there is a significant presence of the microbe on the three foods studied therefore there is a potential food safety risk in consuming these foods by susceptible groups (immune-compromised individuals). The API20E identification system showed five different biotype profiles. The most frequent API20E biotype encountered was 5215773 (44.6%) followed by 5214773 (39.1%). The rest of the biotypes (5215573, 5015773 and 4215773) occurred at a frequency of 2.2%. These biotypes show that there are definite biochemical differences between the isolates. Of the isolates obtained 38% were of the encapsulated phenotype. The highest in-sample occurrence rate of the encapsulated phenotype was in morogo wa dinawa ( 52.6%) followed by moretlwa (40%) and lastly morula (31.3%). Antibiotic susceptibility testing by the disk diffusion method showed that the isolates were most susceptible to 30ug cefotaxime (24.4mm average clearance zone), and totally resistant to 1ug oxacillin and 30ug vancomycin (0.0mm average clearance zone). All of the strains analysed were completely resistant to oxacillin (1ug) and vancomycin (30ug). For cotrimoxazole (25ug), 22.8% of the isolates were completely resistant

Flooding and its influence on diazotroph populations and soil nitrogen levels in the Okavango Delta.

Effects of flooding on soil nitrogen (N), and asymbiotic nitrogen fixing bacterial (diazotroph) populations of the Okavango Delta were investigated. Diazotrophs from the rhizosphere of dominant annual and perennial grasses of the Okavango Delta were isolated on N-free composite media and identified applying morphological and biochemical criteria and Restriction Fragment Length Polymorphism (RFLP). Azotobacter species were found associated mostly with the grasses Andropogon guyanus and Vetevaria nigritiana (103CFU g¿1 rhizosphere soil). Annual grasses such as Eragrostis inamoena, Setaria sphacelata as well as perennials showed insignificant populations

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort