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Bovine tuberculosis (TB) caused by Mycobacterium bovis is a significant health threat to cattle and a zoonotic threat for humans in many developing countries. Rapid and accurate detection of M. bovis is fundamental for controlling the disease in animals and humans, and for the proper treatment of patients as one of the first-line anti-TB drug, pyrazinamide, is ineffective against M. bovis. Currently, there are no rapid, simplified and low-cost diagnostic methods that can be easily integrated for use in many developing countries. Here, we report the development of a loop-mediated isothermal amplification (LAMP) assay for specific identification of M. bovis by targeting the region of difference 4 (RD4), a 12.7 kb genomic region that is deleted solely in M. bovis. The assay's specificity was evaluated using 139 isolates comprising 65 M. bovis isolates, 40 M. tuberculosis isolates, seven M. tuberculosis complex reference strains, 22 non-tuberculous mycobacteria and five other bacteria. The established LAMP detected only M. bovis isolates as positive and no false positives were observed using the other mycobacteria and non-mycobacteria tested. Our LAMP assay detected as low as 10 copies of M. bovis genomic DNA within 40 minutes. The procedure of LAMP is simple with an incubation at a constant temperature. Results are observed with the naked eye by a color change, and there is no need for expensive equipment. The established LAMP can be used for the detection of M. bovis infections in cattle and humans in resource-limited areas., Author summary Although bovine tuberculosis in humans has been eliminated in developed countries, the disease remains a challenge in many developing countries. Routine laboratory methods used to identify tuberculosis (TB) in high-burden countries do not distinguish between the two main causes of TB in humans, namely Mycobacterium tuberculosis and M. bovis. In addition, M. bovis is naturally resistant to one of the first-line drugs used to treat TB called pyrazinamide; therefore, accurate diagnosis of M. bovis is important for proper selection of anti TB drugs. In cattle, surveillance for M. bovis infection is important to obtain data on bovine TB burden and hence provide a basis for the establishment and/or improvement of control programs. In this study, a loop-mediated isothermal amplification (LAMP) based method was developed to identify M. bovis. This LAMP method detected M. bovis within 40 minutes following incubation at constant temperature (66°C) in a battery-powered incubator and results could be read with the naked eye following development of a color change. Our results elaborate a rapid and low-cost LAMP based method for detection and surveillance of M. bovis infection in cattle and humans in resource-limited, endemic areas.

Mealie Meal is one of the by-products of maize from dry milling. It constitutes more significant part of the daily diet of growing population of the f Lusaka District of Zambia. However, reported cases of a cholera outbreak in October 2017-May 2018 were attributed to water contamination in the households of Lusaka. Hitherto there is no previous study or documented data for gastroenteritis caused by microbial contamination from food stores.The main objective of the study was to carry out species identification of Mealie meal spoilage organisms and pathogenic bacteria from selected food stores in Lusaka district from September 2019 – March 2020.Cross-sectional survey (prevalence study) was conducted for food spoilage organisms and pathogenic bacteria of packaged maize meal flour from a selected food store. The number of packaged Mealie meal samples from selected food stores included in the study was 143 samples. Samples were obtained by a simple stratified random selection from food stores in Lusaka District. Thus Mealie Meal samples bought from Street food vendors were 96 (67%), Shops-30 (21%), Malls-17 (11.9%). Subsequently isolation by spread and pour plate methods, and species identification of microbial contamination by Cell Culture processes coupled to microbial morphological and biochemical characterization was performed. Microsoft Office Excel (version 2007) Spreadsheet was employed for the categorical data analysis and summarized graphical presentation of data. The preliminary laboratory findings revealed the following: Spoilage organisms – Aspergillum species, Mucor Species, Candida Species, Clostridium Species and Bacillus Species; Pathogenic Bacteria Species-Clostridium perfringens, Staphylococcus aureus, Clostridium tetani , Bacillus, Escherichia coli, Pseudomonas aeruginosa and Yesinia pestis.It can be established from the laboratory results earlier mentioned that the food poisoning outbreak could evolve from food stores in Lusaka district apart from water contamination.

Background Plague is a flea-borne zoonotic and invasive disease caused by a gram negative coccobacillus bacterium called Yersinia pestis. Plague has caused three devastating pandemics globally namely: the Justinian, Black Death and Oriental plague. The disease in the Eastern Province of Zambia has been reported in Nyimba and Sinda Districts in the past 15 years. The aim of this study was to investigate the molecular epidemiology of plague in the two affected districts. Polymerase Chain Reaction (PCR), targeting Plasminogen activator gene (pla gene) of Y. pestis, was performed on suspected human bubo aspirates (n = 7), rodents (n = 216), shrews (n = 27) and fleas (n = 1494). Of these, one positive sample from each source or host was subjected to sequencing followed by phylogenetic analysis. Results The plasminogen activator gene (pla gene) of Y. pestis was detected in 42.8% bubo aspirates, 6.9% rodents, 3.7% shrew and 0.8% fleas. The fleas were from pigs (n = 4), goats (n = 5) and rodents (n = 3). The sequencing and phylogenetic analysis suggested that the pla gene of Y. pestis in Nyimba and Sinda was similar and the isolates demonstrated a high degree of evolutionary relationship with Antiqua strains from the Republic of Congo and Kenya. Conclusion It can be concluded that pla gene of Y. pestis was present in various hosts in the two districts and the strains circulating in each district were similar and resembles those in the Republic of Congo and Kenya. Electronic supplementary material The online version of this article (10.1186/s12866-017-1146-8) contains supplementary material, which is available to authorized users.

This study was conducted at the livestock/wildlife interface areas of national parks and traditional cattle grazing areas. The main aim of the study was to establish the occurrence of Escherichia coli serogroups isolated from Kafue lechwe antelopes (Kobus leche kafuensis) and pastoral cattle. A total of 593 faecal samples from lechwe (232) and pastoral cattle (361) were conveniently picked from the grazing pastures in the interface areas and cultured for E. coli. From each faecal sample, two or three presumptive E. coli isolates were picked to constitute 1,283 isolates with 574 from lechwe and 708 from cattle. Some of these isolates were found to be similar to Shiga toxin-producing E. coli O157 on CHROMagar and sorbitol MacConkey agar. Only 18 E. coli isolates from Kafue lechwe antelopes were grouped into eight serogroups while 32 from pastoral cattle were grouped into 16 serogroups. The most prevalent type-able serogroups from lechwe antelopes and pastoral cattle were O125 (5.8%) and O29 (4.2%), respectively. On further analysis by fermentation of various sugars, some isolates showed a similar pattern suggesting that the strains were indistinguishable. Key words: Escherichia coli, diarrheagenic, Shiga toxin, Kobus leche kafuensis, pastoral cattle.

The use of molecular techniques to detect Yersinia pestis has enabled remarkable progress in the provision of necessary information on the occurrence of plague. In Tanzania, despite the long history of plague, DNA confirmation on the presence of Y. pestis in human specimens has not been done. This study was conducted in Mbulu district in Northern Tanzania where plague outbreaks have recently been reported. Nine human bubo specimens were investigated for Y. pestis plasminogen activator gene by using polymerase chain reaction (PCR), and two were found to be positive. The two positive amplicons, together with three previously obtained PCR positive rodent samples, were sequenced using a 3130 genetic analyzer and then compared with those available in GenBank by basic local alignment search tool (BLAST). All sequences obtained from both human and rodent samples showed 99% sequence similarity to Y. pestis plasmid pPCP1, detected from ancient DNA, confirming the presence of Y. pestis in humans that possibly sourced from rodents in Tanzania. Key words: Yersinia pestis, human plague, molecular detection, Tanzania.