Molecular Assessment of Anaplasma marginale in Bovine and Rhipicephalus (Boophilus) microplus Tick of Endemic Tribal Belt of Coastal South Gujarat, India.

BACKGROUND AND METHODS: This study described the detection, prevalence and phylogeny of Anaplasma marginale in the bovine (cattle and buffaloes) and Rhipicephalus (Boophilus) microplus tick belonged to the tribal area of coastal South Gujarat, India, by amplifying 576 bp of major surface protein (msp) 5 gene using custom designed primers in the polymerase chain reaction (PCR). RESULTS: The PCR detection limit was up to 20 parasites/µl of blood in sensitivity experiment, and observed 100% specificity against Trypanosoma evansi, Babesia bigemina and Theileria annulata. Prevalence rate of the A. marginale in the bovine (n = 211)) was 18.48% and 6.64% (p < 0.05) as per the PCR and Giemsa stained blood smear, respectively. Febrile animals (35%) observed significantly (p < 0.05) higher incidence rate than the non-febrile (14.62%). The amplified msp5 had single cut site for the EcoR1 enzyme, upon digestion yielded two fragments of 365 and 211 bp on 1.0% agarose gel. The current sequence (KC811329) showed 100% homology and 1064 total score with the published nucleotide sequences of msp5 of A. marginale in the NCBI-BLAST study. Monophyletic relationship was observed with high bootstrap proportion (> 76% in Neighbor-Joining/ Maximum Likelihood) between the current and published nucleotide sequences in the phylogeny. Twenty out of 39 A. marginale infected bovine recorded R. (B.) microplus on their body surface, out of which 18 had detected the infection. The rickettsia was in 55%, 65% and 25% of anterior half, posterior half and egg of tick, respectively. CONCLUSION: The test detected A. marginale in a carrier, pre-symptomatic and symptomatic vertebrate hosts (cattle and buffalo) and different body parts of the starved R. (B.) microplus including its egg. The current genotype could be an explanation for the frequent outbreaks of bovine anaplasmosis in the targeted areas.

Assessment of genetic diversity of zoonotic Brucella spp. recovered from livestock in Egypt using multiple locus VNTR analysis.

Brucellosis is endemic in most parts of Egypt, where it is caused mainly by Brucella melitensis biovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominant Brucella species/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17 Brucella spp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat) from four governorates during a period of five years (2002-2007) was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing). Thirteen strains were identified as B. melitensis biovar 3 while all phenotypic and genetic techniques classified the remaining isolates as B. abortus (n = 2) and B. suis biovar 1 (n = 2). MLVA-15 yielded a high discriminatory power (h = 0.801), indicating a high genetic diversity among the B. melitensis strains circulating among domestic ruminants in Egypt. This is the first report of the isolation of B. suis from cattle in Egypt which, coupled with the finding of B. abortus, suggests a potential role of livestock as reservoirs of several zoonotic Brucella species in the region.

Preliminary assessment of bovine tuberculosis at the livestock/wildlife interface in two protected areas of northern Botswana.

Protected areas of northern Botswana such as the Okavango Delta (OD) or Chobe National Park (CNP) are well-known hot spots for the conservation of African wildlife. However, their infection status regarding bovine tuberculosis (BTB) at the domestic/wildlife interface has never been investigated. To provide preliminary baseline data on the circulation of Mycobacterium bovis in those sites, we performed a cross-sectional survey on 130 buffalo in both protected areas (60 individuals from CNP and 70 from OD) and 818 cattle in their surrounding communal lands (369 in CNP and 449 in the OD). Whole-blood samples were tested using a commercial interferon-gamma assay (IFN-γ) with modifications. The apparent BTB prevalence in buffalo was nil in CNP and 0.7% 95% CI [0.2-1.9] in the OD, while the apparent BTB prevalence in cattle was 0.7% 95% CI [0.2-2.1] in the OD and 2.4% 95% CI [1.2-4.7] in CNP. True prevalence values calculated on the basis of the locally applicable IFN-γ test performance suggested that BTB prevalence was nil in both buffalo populations and in cattle from the OD interface, but reached 2.3% 95% CI [0.2-4.5] in cattle populations around CNP. The results of a questionnaire survey conducted among a sample of farmers living in the communities adjacent to each conservation area (97 and 38 persons in the OD and CNP, respectively) suggested a higher risk of the circulation of M. bovis at the wildlife/livestock interface of the CNP than at that of the OD. However, further comprehensive studies are needed to confirm the circulation of M. bovis and to monitor the inter-species and transboundary transmission of BTB in northern Botswana.

Mastitis in dairy buffalo and cattle in Egypt due to Clostridium perfringens: prevalence, incidence, risk factors and costs.

Although Clostridium perfringens is recognised as an important cause of clostridial enteric diseases, there is only limited knowledge about the association of particular C. perfringens toxinotypes (types A to E) with mastitis in domestic animals. In this study, mastitis was detected in 213/623 (34.12%) and 8/83 (9.64%) of the quarter milk samples collected from cases of clinical mastitis in cows and buffalo, respectively. The micro-organism was isolated in an incidence of 16/357 (4.48%) of milk samples from cows and 1/25 (4.0%) of samples from buffalo. Infection in one quarter was the most typical situation found (83% in cows and 87% in buffalo). Clostridium perfringens infection was also correlated to the season, with the highest proportion of isolates being found during spring (10.71%) and winter (7.07%). Using the classical toxin neutralisation typing method, 17 strains, isolated from cow and buffalo milk, were identified as C. perfringens type A, and selected for molecular analysis. Polymerase chain reaction detected the oecpa gene while the P/cpb and e/etx genes went undetected. The authors believe that C. perfringens has the potential to produce disease on its own or to predispose the udder to disease caused by major mastitis and environmental pathogens.

Estimation of receiver-operating characteristic curves to determine accuracy of a competitive enzyme-linked immunosorbent assay for the serodiagnosis of Brucella infection in domestic water buffalo (Bubalus bubalis) and cattle.

OBJECTIVE: To estimate receiver-operating characteristic (ROC) curves for a competitive ELISA (c-ELISA) that is used in serodiagnosis of brucellosis in water buffalo and cattle, to determine the most appropriate positive cutoff value for the c-ELISA in confirmation of infection, and to evaluate species differences in c-ELISA function. SAMPLE POPULATION: Sera from 4 herds of cattle (n = 391) and 4 herds of water buffalo (381). PROCEDURE: Serum samples were evaluated for Brucella-specific antibodies by use of a c-ELISA. On the basis of previous serologic test results, iterative simulation modeling was used to classify animals as positive or negative for Brucella infection without the use of a gold standard. Accuracy of c-ELISA for diagnosis of infection was compared between cattle and water buffalo by comparison of areas under ROC curves. RESULTS: A positive cutoff value of 30% inhibition for c-ELISA yielded sensitivity and specificity estimates, respectively, of 83.9 and 92.6% for cattle and 91.4 and 95.4% for water buffalo. A positive cutoff value of 35% inhibition yielded sensitivity and specificity estimates, respectively, of 83.9 and 96.2% for cattle and 88.0 and 974% for water buffalo. Areas under ROC curves were 0.94 and 0.98 for cattle and water buffalo, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: ROC curves can be estimated by use of iterative simulation methods to determine optimal cutoff values for diagnostic tests with quantitative outcomes. A cutoff value of 35% inhibition for the c-ELISA was found to be most appropriate for confirmation of Brucella infection in cattle and water buffalo.