Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of Johne's disease in cattle and sheep, has unique iron requirements in that it is mycobactin-dependent for cultivation in vitro. The iron-dependent regulator (IdeR) is a well-characterized global regulator responsible for maintaining iron homeostasis in Mycobacterium tuberculosis (MTB). We identified an orthologous segment in the MAP genome, MAP2827, with >93 % amino acid identity to MTB IdeR. Electrophoretic mobility shift assays and DNase protection assays confirmed that MAP2827 binds the 19 bp consensus motif (iron box) on the MAP genome. Sequencing of MAP2827 from multiple isolates revealed a non-synonymous change (R91G) exclusive to sheep strains. Reporter gene assays and quantitative real-time RT-PCR assays in two diverse MAP strains and in an ideR deletion mutant of M. smegmatis (mc2155) suggested that both sheep MAP IdeR (sIdeR) and cattle MAP IdeR (cIdeR) repress mbtB transcription at high iron concentrations and relieve repression at low iron concentrations. On the other hand, bfrA (an iron storage gene) was upregulated by cIdeR when presented with MTB or the cattle MAP bfrA promoter, and was downregulated by sIdeR in the presence of MTB, or sheep or cattle MAP bfrA promoters, at high iron concentrations. The differential iron regulatory mechanisms between IdeR-regulated genes across strains may contribute to the differential growth or pathogenic characteristics of sheep and cattle MAP strains. Taken together, our study provides a possible reason for mycobactin dependency and suggests strong implications in the differential iron acquisition and storage mechanisms in MAP.

Purpose: Diagnosis of leptospirosis facilitates patient management and initiation of therapy. The microscopic agglutination test (MAT) is the serological test used in reference laboratories because of its high degree of sensitivity and speciÞ city. But the results are not available quickly for patient management. In the present study, in order to develop a simple, rapid immunodiagnostic assay, one of the outer membrane proteins (OMPs), recombinant LipL41 (rLipL41) has been utilised in latex agglutination test (LAT) and ß ow-through assay. Methods: Part of LipL41 gene was expressed in Escherichia coli system and puriÞ ed. The rLipL41 antigen of pathogenic Leptospira interrogans serovar Icterohaemorrhagiae, which is conserved in all pathogenic Leptospira spp. was used as capture antigen in the LAT and ß ow-through test. Both tests are very rapid and could be completed within 5 minutes. The sensitivity and speciÞ city of rLipL41 was assessed and evaluated in LAT and ß ow-through assay in comparison with standard MAT. Results: The sensitivity and speciÞ city of the LAT were 89.70 and 90.45% and ß ow-through assay were 89.09 and 77.70%, respectively. Conclusions: The developed LAT and ß ow-through assays were simple, rapid and economical for the detection of leptospira infection and suitable for large-scale screening of samples in endemic areas without any sophisticated equipment.

The novel infectious bursal disease virus (IBDV) isolate BGE14/ABT1/MVC/India is a very virulent IBDV that was isolated from broiler flocks in southern parts of India during 2014. Here, we report, for the first time in India, the complete genome sequence of BGE14/ABT1/MVC/India, a reassortment strain with segments A and B derived from a very virulent IBDV strain and an attenuated IBDV, respectively. The findings from this study provide additional insight into the genetic exchange between attenuated and very virulent strains of IBDV circulating in the field.

Isolation of Staphylococcus aureus was carried out in a total of 120 retail pork samples and the overall prevalence of S. aureus in retail pork meat was 76.67%. All the isolates were resistant to both Ampicillin and Tetracycline (100%) followed by Cefoxitin, Oxacillin, Erythromycin, Amoxicillin, and Novobiocin. The multiple antibiotic resistance index of majority of the isolates were 0.3 and above. Methicillin resistance based on polymerase chain reaction revealed that 76.09% carried either mecA or mecC. The prevalence of enterotoxigenic S. aureus in pork was 82.61% and of the various toxin genes sei was the major gene followed by seg, seb, sej, sed, seh, sec, and sea in decreasing order. The prevalence of multidrug resistant and virulent S. aureus carrying enterotoxin genes in retail pork meat is a clear indication of the potential of these isolates in causing foodborne intoxication under favorable conditions to the consumers. Practical application Staphylococcus aureus (S. aureus) is a well‐known opportunistic pathogen widely present in a broad host range, including human beings and food producing animals, such as pigs, cows, goats and chickens. It has the potential to contaminate animal products and they gain entry in to the food chain, during processing, preparation and storage. The wide use of antibiotics has led to the emergence of multi drug resistant strains, particularly Methicillin‐resistant S. aureus (MRSA). The present study highlights the prevalence, antimicrobial resistance with special reference to MRSA and enterotoxin gene profile of S. aureus isolated from retail pork meat. The results will provide the insights of the existing situation of antimicrobial resistance in pork meat in India.

The efficacy of a recombinant leptospiral outer membrane protein LipL41 as an antigen for conducting IgG-Enzyme linked immunosorbent assay (ELISA) and latex agglutination test (LAT) for serodiagnosis of bovine leptospirosis was evaluated. The recombinant LipL41 antigen developed and used for detecting the antibodies was specific in detection of the pathogenic serovars of Leptospira, as the expression of the LipL41 antigen is restricted only to pathogenic leptospires. A total of 430 bovine serum samples were subjected to IgG-ELISA and LAT, and the sensitivity and specificity were assessed in comparison with microscopic agglutination test (MAT). The sensitivity and specificity of IgG-ELISA and LAT were 86.84% and 93.16%, and 95.42% and 98.33% respectively. Both the tests are found to be sensitive, specific and concurred with the standard MAT. The study concluded that the rLipL41 protein could be used as a potential diagnostic antigen in different assay formats for bovine leptospirosis.

Toxocara canis is a widespread gastrointestinal nematode parasite of dogs and cause Toxocara larva migrans, an important zoonotic disease in humans on ingestion of infective eggs. Toxocarosis is one of the few human parasitic diseases whose serodiagnosis uses a standardized antigen, T. canis excretory secretory antigen (TES). The present study describes collection of T. canis adult worm, collection and embryonation of T. canis eggs, hatching and separation of T. canis larvae, in vitro maintenance of T. canis second stage larvae for production of TES, concentration of culture fluid TES and yield of TES in correlation with various methods cited in literature.

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