Detection and distribution of anti-leptospiral antibody among dogs and their handlers

@# The incidence of leptospirosis seems to be on the rise and could be an alarming indirect indication of a global re-emergence. It is a potential public health threat when dogs are speculated to be involved in the transmission of leptospirosis through possible subclinical harbouring of Leptospira spp. and subsequent shedding into the environment. This study aimed to detect anti-leptospiral antibodies among dogs and their handlers using the microscopic agglutination test (MAT). Blood samples from 266 apparently healthy dogs and 194 dog handlers were collected at four working dog organisations and four dog shelters. Serum samples were tested using MAT against 20 leptospiral serovars with a cut-off titre >1:100 (dog) and >1:50 (dog handlers). Seventy dogs (70/266; 26.3%) were seropositive mainly against serovars Icterohaemorrhagiae, Ballum, Bataviae and Javanica (titres ranged: 1:100–1:800). Sixty-seven dog handlers (67/194; 34.5%) were seropositive mainly against serovars Grippotyphosa, Icterohaemorrhagiae and Malaysia (titres ranged: 1:50–1:200). Dogs were seropositive due to exposure, vaccination or active infection. Seropositive dog handlers could indicate exposure or active infection. This shows the potential of dogs in maintaining and spreading the infection in Malaysia. Due to the occupational risk as a result of frequent contact with dogs and exposure to contaminated environments, dog handlers should be made aware of the presence of this zoonotic disease.

Molecular detection of Leptospira sp. in cattle and goats in Kelantan, Malaysia after a massive flood using multiplex polymerase chain reaction

@#Flood is a potential driver in spreading waterborne diseases including leptospirosis, which is a zoonotic disease caused by pathogenic bacteria of the genus Leptospira. In the case of leptospirosis, cattle and goats can be incidental hosts and potential carriers of leptospirosis. Traditionally, serology such as microscopic agglutination test (MAT) and isolation of the organisms have been commonly used as the diagnostic approaches in diagnosing leptospirosis. However, nowadays, various molecular techniques have been developed for specific detection of Leptospira sp. such as, polymerase chain reaction (PCR), which is sensitive, specific and rapid in detecting the species. This study detected Leptospira sp. directly from the blood and urine of the animals such as, cattle, goats and sheep in Kelantan after a massive flood by using multiplex PCR (mPCR). From the results collected in the study, four blood samples (0.63%; 4/635) were found to be positive with Leptospira sp. and one urine sample (3.23%; 1/31) was detected as positive with Leptospira sp. The blood and urine samples that were detected to be positive with Leptospira sp. were collected from cattle and goats exposed to the flood. However, no Leptospira sp. was detected from the sheep in this study. Multiplex PCR (mPCR) was successfully used to detect the presence of Leptospira sp. in animals. Apart from that, it is also suggested that flood has a significant role in transmitting the disease to animals.

Isolation and molecular characterization of Brucella melitensis from seropositive goats in Peninsula Malaysia

A study was carried out to isolate Brucella melitensis using established bacteriological and PCR techniques in Brucella seropositive goats in farms in Selangor, Negeri Sembilan, Melaka and Pulau Pinang. Brucella melitensis was isolated from 7 of 134 reactors with the highest isolation from the vaginal swabs (57.14%) followed by the spleen (28.57%), uterine fluid (14.29%). No Brucella was isolated from the lymph nodes. PCR confirmed all the seven isolates as B. melitensis and isolates were phylogenetically related to other isolates from India, Iran, and Israel but most closely related to isolates from Singapore.

Rapid detection of pathogenic leptospires by lyophilized reagent-based Polymerase Chain Reaction

A simple and reliable tool for the early diagnosis of leptospirosis is urgently needed. We report the development of a lyophilized reagent-based polymerase chain reaction (PCR) assay targeting lipL32 gene, which is present only in pathogenic leptospires. To determine the effectiveness of the newly developed assay in the early diagnosis of leptospirosis, the sensitivity and specificity was evaluated. In simulated clinical samples, the assay was able to detect 102 and 103 leptospires/ml in spiked urine and blood samples, respectively. In experimentally infected animals, leptospiral DNA could be detected in blood and lung samples as early as Day 1 post infection. This assay was also shown to be stable and remained sensitive for up to five months at ambient temperature. Hence, this lyophilized reagent-based PCR assay with high specificity, sensitivity and stability would provide a simple, rapid and reliable method in diagnosing acute leptospirosis, especially in the field of veterinary medicine

Serological prevalence of leptospiral infection in wild rats at the National Service Training Centres in Kelantan and Terengganu

One hundred and sixty eight rats were trapped from the National Service Training Centres (NSTC) in Kelantan and Terengganu from October 2008 to May 2009. Microscopic agglutination test (MAT) was performed to detect the presence of agglutinating antibodies to Leptospira among the rats caught. All the MAT positive rats were identified as Rattus tiomanicus. In Kelantan, 17.3 % (14/81) of the rats had leptospiral antibodies to serovars Icterohaemorrhagiae (12.3%), Canicola (2.5%), Ballum (1.2%), and Pyrogenes (1.2%). In Terengganu, 18.4% (16/87) of the rats had antibodies to serovars Icterohaemorrhagiae (15%), Canicola (1.1%), Pyrogenes (1.1%) and Hebdomadis (1.1%). This study indicated that Leptospira serovars were prevalent in the rat population in the study areas and could be a source of infection to humans. Therefore, control of the rat population in all NSTC is critical to prevent outbreaks of leptospirosis amongst the NSTC trainees.