EMERGENCE OF COAGULASE POSITIVE METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS ISOLATED FROM BUFFALO MASTITIS MILK SAMPLES

The present study was undertaken to screen methicillin resistant Staphylococcus aureus (MRSA) in mastitis buffalo milk samples from northern India. A total of 120 buffalo mastitis milk samples were collected from individual quarter over a one year period mainly from animals reared by marginal farmers. The isolates were presumptively confirmed by growing the organism in selective media and biochemical tests. A total of 52 samples were presumptively confirmed as Staphylococci on the basis of growth in Mannitol Salt Agar (MSA); out of which 12 samples were coagulase positive Staphylococcus aureus (S. aureus) by growth in Baird Parker Agar (BPA) and tube coagulase test. Antibacterial profiling and growth on Methicillin resistant Staphylococcus aureus (MeReSa) Agar indicated five isolates as MRSA. Further PCR of specific gene segments and their subsequent characterization based on 16S ribosomal RNA, of staphylo-coagulase and mecA confirmed the findings. The study accentuates the importance of determining the causal agents of mastitis, antibacterial profiling so as to enable the clinicians and researchers to intervene and adopt effective control measures

Recombinant CFP-10 as antigen for diagnosis and quantification of IFN-γ expression by real-time PCR in guinea pigs sensitized with<em> Mycobacterium bovis</em>

875-882Culture filtrate protein (CFP-10) is a low molecular weight protein and is an early secretory protein in Mycobacterium tuberculosis culture filtrate and plays key roles in tuberculosis pathogenesis and in the stimulation of immunity. Keeping in view the important role of CFP10, we investigated the CFP10 gene in Indian Mycobacterium bovis (M. bovis) (3/86Rv) and its expression in suitable prokaryotic host for its diagnostics potential by single intradermal test (SID). Real-time PCR was used to quantify mRNA interferon-γ expression levels. The study concluded that the expression of IFN-γ mRNA in blood was found up to 19.962, 20.795, 9.633, 34.511 and 1.688 times in rCFP10, bovine PPD (purified protein derivative), avian PPD, conA and PBS stimulated groups, respectively as compared to healthy control group. The mRNA expression level of bovine PPD and avian PPD stimulated group was found statistically significant (at P P <0.01) in comparison to ‘without antigen stimulated’ group

Abortions in an organized dairy farm from North India reveal the possibility of breed susceptibility to Bovine Brucellosis

The present study was undertaken over a three year period (2012–2014) in an organized dairy farm located in North India to ascertain Brucella abortus as the putative cause of abortion. The dairy farm maintained cattle of Frieswal, Crossbred and Sahiwal breeds and followed calf-hood vaccination with Brucella abortus Strain 19 live vaccine in all the heifers. Even with the recommended vaccination schedule and good managemental practices in place, 88 cases of abortions clinically suspected of bovine brucellosis (40 from Frieswal breed, 17 from Crossbred cattle and 31 from Sahiwal breed) were reported from this farm. From these abortion cases, bacteriological isolation was possible in only four dams while 16 dams were found to be serologically positive in Serum Tube Agglutination Test (STAT). Molecular screening by PCR assay (specific for the bcsp31 gene of B. abortus) revealed that 24 dams were positive, out of which 20 were from Frieswal breed and rest four were from Crossbred herd. Prominently, all Sahiwal dams were found to be negative in bacteriological isolation and also in PCR assay. These results thus indicate towards the possibility of breed predisposition to abortions due to B. abortus infection. Statistical analysis by Fischer exact test (p<0.01) too substantiated that breed susceptibility exists among these PCR positive cases. This study is novel as breed variation in abortions due to B. abortus in cattle is being documented for the first time. Seven representative PCR amplicons generated during the study were also sequenced and submitted to NCBI GenBank. Moreover, this study also accentuates the importance of PCR screening especially in vaccinated herd and raises concerns on over-dependence of serological assays when intensive vaccination is practised without any concomitant DIVA strategy. Thus, besides assisting in planning pragmatic control strategies against bovine brucellosis these findings are also imperative from ‘One Health’ context, also. Keywords: Bovine brucellosis, Brucella abortus strain 19 (S19) live vaccine, Serum tube agglutination test, bscp31 gene PCR, Vaccination failure, Breed susceptibilit

Comparative sequence analysis of morbillivirus receptors and its implication in host range expansion

SLAM (CD150) and nectin-4 are the major morbillivirus receptors responsible for virus pathogenesis and host range expansion. Recently, morbillivirus infections have been reported in unnatural hosts, including endangered species, posing a threat to their conservation. To understand the host range expansion of morbilliviruses, we generated the full-length sequences of morbillivirus receptors (goat, sheep, and dog SLAM, and goat nectin-4) and tried to correlate their role in determining host tropism. A high level of amino acid identity was observed between the sequences of related species, and phylogenetic reconstruction showed that the receptor sequences of carnivores, marine mammals, and small ruminants grouped separately. Analysis of the ligand binding region (V region; amino acid residues 52–136) of SLAM revealed high amino acid identity between small ruminants and bovine SLAMs. Comparison of canine SLAM with ruminants and non-canids SLAM revealed appreciable changes, including charge alterations. Significant differences between feline SLAM and canine SLAM have been reported. The binding motifs of nectin-4 genes (FPAG motif and amino acid residues 60, 62, and 63) were found to be conserved in sheep, goat, and dog. The differences reported in the binding region may be responsible for the level of susceptibility or resistance of a species to a particular morbillivirus.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Single-cell analysis reveals lasting immunological consequences of influenza infection and respiratory immunization in the pig lung.

The pig is a natural host for influenza viruses and integrally involved in virus evolution through interspecies transmissions between humans and swine. Swine have many physiological, anatomical, and immunological similarities to humans, and are an excellent model for human influenza. Here, we employed single cell RNA-sequencing (scRNA-seq) and flow cytometry to characterize the major leukocyte subsets in bronchoalveolar lavage (BAL), twenty-one days after H1N1pdm09 infection or respiratory immunization with an adenoviral vector vaccine expressing hemagglutinin and nucleoprotein with or without IL-1β. Mapping scRNA-seq clusters from BAL onto those previously described in peripheral blood facilitated annotation and highlighted differences between tissue resident and circulating immune cells. ScRNA-seq data and functional assays revealed lasting impacts of immune challenge on BAL populations. First, mucosal administration of IL-1β reduced the number of functionally active Treg cells. Second, influenza infection upregulated IFI6 in BAL cells and decreased their susceptibility to virus replication in vitro. Our data provide a reference map of porcine BAL cells and reveal lasting immunological consequences of influenza infection and respiratory immunization in a highly relevant large animal model for respiratory virus infection