Contamination Levels and Identification of Bacteria in Milk Sampled from Three Regions of Tanzania: Evidence from Literature and Laboratory Analyses.

Milk in Tanzania has been reported to be contaminated with large number of bacteria. This is because (1) milk is obtained from animals with unknown health status, (2) good milking and handling practices are to a large extent not observed, and (3) marketing and distribution are done in informal channels. These factors are potential causes of milk-borne diseases and milk quality loss. The aim of this study was to assess nutritional risks in milk as reported in literature over a period of 20 years and through analyses of samples collected during the present study. The issues highlighted in literature were high bacteria and coliform counts exceeding standard levels in East Africa, prevalence of bacteria and drug residues in milk, and adulteration. Based on performed analyses, total bacterial count 1.0 × 107 colony forming units per millilitre (cfu/ml) and total coliform count 1.1 × 107 cfu/ml, also greater than recommended levels, were found. Ten bacteria types were isolated from milk samples (five, Pseudomonas aeruginosa, Listeria monocytogenes, Listeria innocua, Listeria ivanovii, and Klebsiella spp. are reported in Tanzanian for the first time). Two drugs tetracycline and sulphur were detected. Therefore, it is worth noting that integrated research is needed to evaluate the situation and address these challenges.

A review on prevalence, control measure, and tolerance of Tanzania Shorthorn Zebu cattle to East Coast fever in Tanzania.

In Tanzania, control of East Coast fever (ECF) has predominantly relied on tick control using acaricides and chemotherapy, little on ECF vaccination, and very little on dissemination regarding animal immunization. In this paper, the prevalence, control measure, and tolerance of Tanzania Shorthorn Zebu (TSHZ) cattle to ECF are reviewed. In addition, the opportunities available for reducing the use of acaricides for the benefit of the farmers in terms of reduction of costs of purchasing acaricides and environmental pollution are described. The tick distribution and epidemiological factors for ECF such as the agro-ecological zones (AEZ), livestock production systems (LPS), strain, and age of the animals are also described. These factors influence the epidemiology of ECF and the distribution of TSHZ strains in different geographic locations of Tanzania. We have further showed that there is a tendency of farmers to select among the strains of TSHZ for animals which can tolerate ticks and ECF and crossbreed them with their local strains with the aim of benefiting from the inherent characteristics of the most tolerant strains. Generally, many strains of TSHZ cattle are tolerant to tick infestation and ECF infection and can be bred to respond to the needs of the people. In this review paper, we recommend that in future, ECF epidemiological studies should account for factors such as livestock production system, agro-climate, breed of animal, tick control strategy, and the dynamic interactions between them. In conclusion, we have demonstrated that an integrated control method involving use of acaricides, immunization, and ECF-tolerant/-resistant animals is required.

Indels within promoter and intron 1 of bovine prion protein gene modulate the gene expression levels in the medulla oblongata of two Japanese cattle breeds.

Genetic differences which exist in the prion protein gene (PRNP) have been reported to influence susceptibility of humans, sheep and goats to prion diseases. In cattle, however, none of the known coding polymorphisms has a direct effect on bovine spongiform encephalopathy (BSE). It has been reported that 23-bp insertion/deletion (indel) polymorphisms within the promoter region have a tentative association to BSE susceptibility in German cattle, and a lower number of 24-bp repeat units in the open reading frame (ORF) was reported to reduce BSE susceptibility in transgenic mice. In this study, because of the hypothesis that bovine PRNP promoter polymorphisms cause changes in PRNP expression, we genotyped PRNP polymorphisms in the promoter and intron 1 using 218 genomic DNA samples from two Japanese cattle breeds. We also analysed the expression levels of prion in 40 animals by quantification of real-time PCR using mRNAs extracted from the medulla oblongata to study the relationship between PRNP genotypes and PRNP expression. We found a significant correlation between promoter indel polymorphisms and PRNP-mRNA expression (P(0.0413)) and therefore hypothesize that differences in polymorphisms could be one of the causes of differences in PRNP expression levels. We also report a novel difference in PRNP expression (P < 0.0001) between Japanese Black and Japanese Brown cattle breeds. There was no significant difference based on age and sex of the animals.