Molecular characterisation of Rhipicephalus sanguineus sensu lato ticks from domestic dogs in Nigeria.

Rhipicephalus sanguineus is the most widely reported tick in the world. Molecular characterisation is important to verify its taxonomic status in the different parts of the world. In this study, we provide information on the molecular characterisation of R. sanguineus tick of dogs collected from Nigeria. Ticks were collected from 62 of 93 sampled dogs. The collected ticks were subjected to morphological identification with the aid of appropriate entomological keys. Deoxyribonucleic acid (DNA) was extracted from the most prevalent tick species (R. sanguineus) and was subjected to further molecular characterisation protocols. The partial mitochondrial 16S rRNA gene sequences (∼300 bp) were obtained from representative specimens. Data were statistically analysed using the chi-square (χ2 ) test. Phylogenetic analysis was performed including different lineages of R. sanguineus (sl) from Africa, Asia, Europe and America, and other species belonging to the R. sanguineus 'tropical lineage' (R. linnaei) as well as Rhipicephalus turanicus and Ixodes ricinus. Results of this study showed that R. sanguineus was the most abundant ticks of dogs with a prevalence of 61.8% (68/110; 95% CI = 52.5-70.54), followed by Amblyomma variegatum (20.0%) and Haemaphysalis leachi (18.2%). The molecular analysis shows that they are genetically different from the temperate strains but closely related to those from other West African countries. There is a need to establish the vector competence of this common Nigerian dog tick.

Cattle breeding, trypanosomosis prevalence and drug resistance in Northern Togo.

African Animal Trypanosomosis (AAT) is a major disease of cattle in Togo and its control is essentially based on chemotherapy. However, because of excessive use of trypanocides during the past decades, chemo-resistance in the parasites has developed. In order to assess the current situation of AAT and resistance to trypanocidal drugs in Northern Togo, a study was conducted on cattle from December 2012 to August 2013 in the regions of Kara and Savanes. An initial cross-sectional survey was carried out in 40 villages using the Haematocrit Centrifugation Technique (HCT). Out of these, 5 villages with a trypanosome prevalence of >10% were selected for a block treatment study (BT) with diminazene diaceturate (DA: 3.5mg/kg for a 14-day follow-up) and isometamidium chloride (ISM: 0.5mg/kg for a 28-day follow-up). Positive blood samples collected during the parasitological surveys and an equivalent number of negatives were further analyzed by PCR-RFLP for trypanosome species confirmation and molecular diagnosis of resistance to DA in Trypanosoma congolense. The results from 1883 bovine blood samples confirmed a high overall trypanosome prevalence of 10.8% in Northern Togo. PCR-RFLP revealed that T. congolense is the dominant pathogenic trypanosome species (50.5%) followed by T. vivax (27.3%), and T. brucei (16.2%). The BT showed varying levels of treatment failures ranging from 0 to 30% and from 0 to 50% for DA and for ISM respectively, suggesting the existence of resistant trypanosome populations in the study area. Our results show that AAT still represents a major obstacle to the development of cattle husbandry in Northern Togo. In areas of high AAT risk, a community-based integrated strategy combining vector control, rational use of trypanocidal drugs and improving the general condition of the animals is recommended to decision makers.

Drug quality analysis through high performance liquid chromatography of isometamidium chloride hydrochloride and diminazene diaceturate purchased from official and unofficial sources in Northern Togo.

Trypanocidal drugs remain the most accessible and thus commonly used means of controlling tsetse transmitted animal African trypanosomosis. In Togo, trypanocides are sold on official as well as unofficial markets, but the quality of these trypanocides is undocumented so a drug quality assessment study was conducted from May 2013 to June 2014. Trypanocides supplied by European, Indian and Chinese pharmaceutical companies and sold on official and unofficial markets in Togo were purchased. In total fifty-two trypanocides were obtained, 24 of these samples from official markets and 28 from unofficial markets made up of a total of 36 diminazene diaceturate and 16 isometamidium chloride hydrochloride samples. The samples were analysed in the reference laboratory of the OIE (World Organisation for Animal Health), Laboratory for the Control of Veterinary Medicines (LACOMEV) in Dakar which uses galenic testing and high performance liquid chromatography (HPLC) testing as standard reference analysis methods. The results revealed a high proportion of trypanocides of sub-standard quality on the Togolese market: 40% were non-compliant to these quality reference standards. All of the HPLC non-compliant samples contained lower amounts of active ingredient compared to the concentration specified on the packaging. Non-compliance was higher in samples from the unofficial (53.57%) than from the official markets (25%; p=0.04).The main drug manufacturers, mostly of French origin in the study area, supply quality drugs through the official legal distribution circuit. Products of other origins mostly found on illegal markets present a significantly lower quality.

Phenotypic and genotypic characterisation of Brucella strains isolated from cattle in the Gambia.

Thirty-five serum samples and six hygroma fluid samples were collected from sexually mature cattle in one herd with clinical signs of brucellosis (abortion and hygromas) in the Western Region of the Gambia in order to isolate and characterise Brucella species. Information on the sex, age, number of calvings, number of abortions, presence of hygromas, and presence of orchitis was also collected for each animal sampled. Twenty-six (74 per cent) of the serum samples were positive in the rose bengal test and 29 (83 per cent) were positive by indirect ELISA. Three isolates of Brucella, biotyped as Brucella abortus biovar 3, were cultured from six hygroma fluid samples. The multiple locus variable number tandem repeat analysis assay clustered the isolates as B abortus with the same profile for the three isolates, suggesting a common origin of contamination.