Aim: To study the seroprevalence of leptospirosis in dogs in Kerala and to identify the most prevalent serovar. Materials and Methods:A total of 205 sera collected from dogs were screened for the presence of antibodies against leptospirosis by Microscopic Agglutination Test (MAT).Results: A seroprevalence rate of 71.12 per cent was observed. Leptospira interrogans serovar Autumnalis was found to be the most prevalent serovar followed by Australis, Pomona, Canicola, Pyrogenes, Icterohaemorrhagiae, Javanica and Patoc. Conclusions:incorporation of these in the vaccines because the immunity against leptospirosis is serovar specific.

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.

2005.Cloning and characterization of the tbpA gene encoding transferring-binding protein (TbpA) from Pasteurella multocida serogroup B:2 (strain P 52 ). Veterinary Research Communications, 29(6), 537^542

The aim was to isolate and characterize Riemerella anatipestifer organisms from disease outbreaks in ducks in Kerala.Materials and Methods: Ducklings, suspected of Riemerella infection, were sacrificed and subjected to post-mortem examination. Heart blood smears and impression smears from liver and spleen were examined for the presence of pathogenic organisms. Heart blood, lung, liver, and spleen collected aseptically from the birds were subjected to isolation trials in brain heart infusion agar and 10% bovine blood agar. The isolates were characterized based on morphology, cultural characteristics and biochemical tests, and their identity were confirmed by polymerase chain reaction (PCR) and the PCR amplified DNA was sequenced. The antibiotic sensitivity testing of the isolates were carried out using six antibiotics viz ciprofloxacin, chloramphenicol, enrofloxacin, amoxycillin, cotrimoxazole, and gentamicin.Results: Colonies suggestive of Riemerella organisms could be isolated on blood agar. Biochemical characterization and PCR confirmed the identity of isolates as R. anatipestifer. The nucleotide sequence of the PCR product showed 99% homology to the R. anatipestifer sequences in the NCBI. The antibiogram revealed that the organisms were sensitive to ciprofloxacin, enrofloxacin, and gentamicin. Conclusion:The present study suggests that the PCR assay can facilitate fast and proper identification of R. anatipestifer infection in ducks. The assay can also differentiate between R. anatipestifer and Pasteurella multocida and can replace the traditional methods of differentiation which are cumbersome and time-consuming.

Schistosomosis has been recognised as one of the major parasitic diseases of livestock and human beings. Schistosoma spindale is the major cause of visceral schistosomosis among bovines of Kerala State. Besides pathology in animals, it has been long known that cercariae of S. spindale are a common cause of dermatitis in human beings in Asia. However, detection of this disease based on coprology has underestimated the prevalence of this economically important disease among cattle of the State. An efficient diagnostic tool providing unequivocal evidence of infection in living animals is perhaps, the key to formulate and deliver control measures to the target population. It is also crucial for an enhanced understanding of parasite epidemiology. The utility of excretory-secretory proteins as diagnostic and vaccine candidates for schistosomosis has been a focus of medical research since long. There exists a paucity of information with regard to analysis of ES proteins of S. spindale and their incorporation to develop sensitive and specific serodiagnostic tool. Hence a study was designed to evaluate the efficacy of Dot-ELISA incorporating different antigens of S. spindale and to validate the test under field conditions.

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Genetic improvement in livestock was achieved earlier by selective breeding of individuals with superior phenotypes. Now due to the advances in molecular genetics and biotechnology candidate genes of economic traits can be included in selection for breeding programmes. Genes responsible for the resistance/susceptibility to infections with various pathogens (Major Histo Compatibility (MHC) genes, Solute Carrier family11 member A1 (SLC11A1) gene, Toll Like Receptor (TLR) genes etc.), have been recently identified and characterized in human beings as well as in many animals . Among these the role of SLC11A1 gene is very important due to its association with resistance/ susceptibility to various intracellular pathogens in human as well as in livestock species. The SLC11A1 gene, formerly known as natural resistance-associated macrophage protein 1 (NRAMP1) encodes an integral membrane protein regulating the activity of macrophages. Genetic resistance/ susceptibility to diseases due to candidate gene polymorphisms could be used in selection and breeding for disease resistance in animals.

Schistosomosis and amphistomosis are the two economically important and widely prevalent snail-borne trematode infections in grazing cattle of southern India. Acute infections are symptomatically similar and difficult to detect by routine microscopy for eggs. The present study was directed towards the development of a copro-polymerase chain reaction (copro-PCR) for detection of bovine schistosome species, using custom-designed primers targeting 18S and 28S ribosomal RNA as well as mitochondrial DNA. The study demonstrated the enhanced diagnostic specificity of mitochondrial DNA markers over ribosomal RNA genes as genus-specific probes to detect schistosomes. We developed a sensitive PCR assay using primers designed from mitochondrial DNA sequences targeting the partial rrnl (16S rRNA), tCys (transfer RNA for cysteine) and partial rrnS (12S rRNA) genes of Schistosoma spindale to specifically detect schistosome infection from faecal samples of naturally infected bovines. The salient findings of the work also throw light on to the high similarity of the ribosomal RNA gene sequences of schistosomes with those of Gastrothylax crumenifer and Fischoederius elongatus, the most prevalent pouched amphistomes of the region. Further investigation has to be directed towards unravelling the complete gene sequences of 18S and 28S ribosomal RNA as well as mitochondrial DNA sequences of amphistome isolates from India.