BackgroundRecently, there have been attempts to understand the molecular epidemiology of Sarcoptes scabiei, to evaluate the gene flow between isolates of S. scabiei from different hosts and geographic regions. However, to our knowledge, a molecular study has not been carried out to assess the molecular diversity and gene flow of Sarcoptes mite in a predator/prey ecosystem.ResultsOur study revealed an absence of gene flow between the two herbivore (Thomson's gazelle and wildebeest)- and between the two carnivore (lion and cheetah)-derived Sarcoptes populations from Masai Mara (Kenya), which is in discrepancy with the host-taxon law described for wild animals in Europe. Lion- and wildebeest-derived Sarcoptes mite populations were similar yet different from the Thomson's gazelle-derived Sarcoptes population. This could be attributed to Sarcoptes cross-infestation from wildebeest ("favourite prey") of the lion, but not from Thomson's gazelle. The cheetah-derived Sarcoptes population had different subpopulations: one is cheetah-private, one similar to the wildebeest- and lion-derived Sarcoptes populations, and another similar to the Thomson's gazelle-derived Sarcoptes mite population, where both wildebeest and Thomson's gazelle are "favourite preys" for the cheetah.ConclusionsIn a predator/prey ecosystem, like Masai Mara in Kenya, it seems that Sarcoptes infestation in wild animals is prey-to-predator-wise, depending on the predator's "favourite prey". More studies on the lion and cheetah diet and behaviour could be of great help to clarify the addressed hypotheses. This study could have further ramification in the epidemiological studies and the monitoring protocols of the neglected Sarcoptes mite in predator/prey ecosystems.

The sanitary control of threatened wild animals is of pivotal interest for their conservation. This task, however, is highly complex in wildlife/livestock systems. In this paper we report findings from a 2-year cross-sectional study of the epidemiology and attempted control of a Sarcoptes mite infestation in the threatened cheetah population in Masai Mara (Kenya), and discuss its interaction with sympatric wild (lion, wildebeest and Thomson's gazelle) and domestic (dog, cattle and sheep) animals. Sarcoptes scabiei was isolated from cheetahs, Thomson's gazelles, wildebeests, lions, cattle, goats and dogs; Psoroptes ovis, on the other hand, was only isolated from sheep. The prevalence study revealed 12·77% infection rates in cheetahs, 4·7% in dogs, 0·8% in Thomson's gazelles, 0·8% in sheep, 0·09% in cattle, and 0·09% in goats, while it opportunistically affected lions and wildebeest. Our study revealed that prevalence of Sarcoptes mite in cheetah population was not associated with the studied geographical blocks, animal sex or the presence of affected domestic animals. Cheetah infection with S. scabiei was associated with the climatic conditions (dry more than wet season) and the balancing between the total number of Thomson's gazelles and the prevalence of infected individuals. Apparently the high prevalence of mangy gazelles has a negative effect on cheetah; this negative effect was reduced when the number of healthy gazelles was increased. Treatment with injectable ivermectin of the clinically affected wild and domestic animals during the first year of this study was associated with much lower incidence of sarcoptic mange during the second year.

The camel milk trade in Kenya has evolved significantly from a small-scale business undertaken in local villages to its current status involving a large number of different stakeholders supplying urban towns, particularly Nairobi City. Despite the evident growth pattern, the supply of camel milk to Nairobi has largely remained informal, with minimal enforcement of regulations. The aim of this study was to characterise the camel milk system supplying Nairobi and assess its governance, main challenges and the potential food safety risk practices.A value chain analysis framework was used to carry out data collection between August 2014 and July 2015. Qualitative and quantitative data were collected through focus group discussions and key informant interviews with stakeholders operating in different nodes of the value chains.Three milk value chains supplying Nairobi were identified and mapped: the Isiolo chain, the Kajiado chain and the camel milk processing company chain. Overall, the results indicate that 94% of the milk supplied to Nairobi city is informally traded (traded without any effective regulation), while 6% originates from a formal milk processing company. In the informal chains, milk traders (mostly women) were reported to play a pivotal role in the organisation and daily functioning of the chains. The processing company had partly integrated activities and reported exporting 5% of their products to regional and international markets.Food safety themes identified were associated with i) lack of cold chain, ii) gaps in hygiene practices, particularly at farm and market levels, iii) consumption of raw camel milk, and iv) lack of food safety training, among other issues. Low level involvement by government agencies in enforcing stipulated food safety measures were reported in the informal chains, as these concentrate efforts in the regulation of dairy milk chains. Isiolo milk traders were identified as the dominant group, setting milk prices and providing sanctions.The framework and findings obtained can help future research and policy makers to reach informed decision about what to regulate, where to target and importantly how to make the camel milk value chain more efficient and safer.

Background: Salmonellosis is considered one of the most widespread food-borne zoonoses in industrialized as well as developing countries. The presence of Salmonella in food animals at slaughter and the consequent cross-contamination of edible carcass tissues present a significant food safety hazard. Methodology: Samples were collected from randomly selected pigs at the Ndumbuini abattoir in Nairobi. Isolates were confirmed to be Salmonella by biochemical tests and characterised by serotyping, phage typing and plasmid analysis. Minimum inhibitory concentrations (MICs) of eight antimicrobials were determined and the resistant isolates were screened for resistance genes by PCR. Results: Sixteen (13.8%) of 116 samples were positive for Salmonella. Three Salmonella enterica subsp. enterica serovars, namely Saintpaul, Braenderup, and Heidelberg were identified, S. Saintpaul being predominant. Antimicrobial resistance was found in 35.7% of the isolates. The S. Heidelberg isolates were susceptible to all the antimicrobials tested. Multidrug resistance was found in 7.1% of the Salmonella isolates. Plasmids were only detected in S. Heidelberg. Ampicillin resistance was based on expression of a bla TEM gene, while chloramphenicol, streptomycin, and tetracycline resistances were encoded by the genes catA1, strA, and tet(A), respectively. Conclusions: Pigs may serve as reservoirs of antimicrobial resistant Salmonella and slaughterhouse cross-contamination of pork may be a food safety risk.

Objectives:To determine the frequency of resistance of Staphylococcus aureus to various antimicrobial agents, and the relationship between antimicrobial resistance of the isolates and carriage of plasmids. Design: A random sampling of milk and meat samples was carried out. Setting: Milk was collected from various dairy co-operative societies in Nairobi and Kiambu districts. Minced meat samples were purchased from various outlets in the city of Nairobi. Subjects: Ninety six Staphylococcus aureus isolates from milk (seventy five isolates) and minced meat (twenty one isolates) samples. Main outcome measures: Plasmid profiles and antimicrobial susceptibility tests to ampicillin, lincomycin, penicillin, erythromycin, methicillin, minocycline, cotrimoxazole and chloramphenicol. Results: Seventy one per cent of the isolates carried between one and six plasmids of molecular sizes ranging from 0.1 to 14.5 kilobases. High frequency of resistance was observed with lincomycin (67.7%), penicillin (66.7%) and cotrimoxazole (51%). A high percentage (76%) of isolates were susceptible to minocycline followed by erythromycin (57.3%). Most (80.2%) of isolates were multiply resistant to between two and six antibiotics. Conclusion: Most Staphylococcus aureus isolates were multiply resistant to various antimicrobial agents, but there was no apparent relationship between carriage of plasmids and antimicrobial resistance. Milk and meat may contain resistant Staphylococcus aureus posing a potential risk to consumers.