The role of small ruminants in the epidemiology of leptospirosis.

Leptospirosis is a common global zoonotic disease of man and all farm animals. Although most leptospiral infections in sheep and goats are asymptomatic, they may play a role in the epidemiology of the disease by the spread of Leptospira through the urine. This study was carried out to evaluate the role of sheep and goats in the epidemiology of leptospirosis. Blood and urine samples were taken from 210 goats and 246 sheep. To detect antibodies, sera samples were tested with 8 live serovars of L. interrogans (Hardjo, Pomona, Grippotyphosa, Canicola, Ballum, Icterhemorrhagiae, Tarasovi, and Australis) by MAT. Then, urine samples were tested by Nested PCR targeting 16S rRNA gene for detection of pathogenic Leptospira. Results of MAT showed that 10.95% of goats and 8.53% of sheep had antibodies against at least one examined serovars. In both species, the highest reacting was L. i. Pomona with a rate of 68.18% and 56% in sheep and goats, respectively. Moreover, in PCR, 2 (0.95%) urine samples of goat and 12 (4.87%) urine samples of sheep were positive. All of the MAT positive studied animals were PCR negative and, statistical analysis showed that there was no relationship and agreement between the results of PCR and MAT in sheep (kappa = - 0.07, p > 0.05) and goats (kappa = - 0.02, p > 0.05). Finally, it is concluded that sheep and goats can excrete L. interrogans in the urine and thus transmit them to other animals and humans.

Seroprevalence and risk factors of brucellosis in Arabian horses.

BACKGROUND: Brucellosis, as a zoonotic disease, mainly occurs in horses by Brucella abortus, Brucella canis and Brucella suis. The disease in equines is often asymptomatic, but the clinical signs in horses are mostly characterized by bursitis, arthritis and tenosynovitis. OBJECTIVES: This study, thus, aimed to determine the seroprevalence of brucellosis and its associated risk factors in the Arabian horses of Khuzestan province, South-west Iran. METHODS: To that end, the blood samples randomly collected from 180 Arabian horses were analyzed for the presence of anti-Brucella antibodies by Rose Bengal plate test (RBPT), serum agglutination test (SAT), 2-mercaptoethanol test (2-ME) and a commercial i-ELISA kit. RESULTS: The ROC curve analysis showed that the best cut-off point for S/P values in i-ELISA turned out to be 26.25%. The results showed that the overall seroprevalence of brucellosis based on parallel interpretation of the test results was 12.22% (Positive/Tested = 22/180). The prevalence of acute and chronic brucellosis was 8.3 and 3.9%, respectively. The seroprevalence of brucellosis with RBPT and i-ELISA methods was 1.11% (2/180) and 7.22% (13/180), respectively. According to what SAT revealed, 9.44% (17/180) of sera had a titer of 40 or greater, and at 2-ME, 7.22% of samples (13 out of 180 samples) depicted a titer of 40. The results of i-ELISA, SAT and 2-ME were significantly different from those of RBPT (p < 0.01); however, there was no significant difference between i-ELISA, SAT and 2-ME in findings (p > 0.05). CONCLUSIONS: The results of this study recommend that i-ELISA be used for screening purposes of brucellosis in horses. The findings confirmed that Arabian horses are natural hosts for the Brucellae. It is, thus, necessary to adopt appropriate prevention and control programs by health authorities and horse owners so as to reduce the distribution and transmission of the infection in the regions where brucellosis is prevalent.

Isolation and identification of bubaline herpesvirus 1 (BuHV-1) from latently infected water buffalo (Bubalus bubalis) from Iran.

In order to isolate buffaloes herpesvirus 1 (BuHV-1) from latently infected water buffalo (Bubalus bubalis), 16 buffalo heifers were selected from a herd. At first, animals were bled and their sera were tested by virus neutralization (VN) test, using bovine herpesvirus 1 (BoHV-1). According to the results of VN test and dexamethasone injection (0.1 mg/kg BW) for 5 consecutive days, the examined buffaloes were divided into 4 groups. Vaginal and nasal swabs were daily collected from all buffaloes from day 0 to 10 days later. Based on the cytopathic effects in cell culture, a herpesvirus was isolated only from nasal swabs of three seropositive buffaloes which they had received dexamethasone. The nasal swabs of these three buffaloes were also positive in PCR, using primers specific for ruminant herpesviruses gD gene. The identity of the isolated viruses was determined according to partial amino acid sequences of gD, deduced from the nucleotide sequences of the PCR products. On the basis of sequence alignment, phylogenetic analysis, and genetic distances, the three buffalo virus isolates were more closely related to BuHV-1 and BoHV-5 than to BoHV-1.