Infectious salmon anemia virus (ISAV) is classified in the genusIsavirus of the family Orthomyxoviridae. Although virulence variation of ISAV can be demonstrated experimentally in fish, virus strain identification is ambiguous because the correlates of pathogenicity and/or antigenicity of ISAV are not well defined. Thirteen ISAV isolates characterized for their ability to kill fish were used to search for markers of virulence on the virus surface glycoprotein genes; haemagglutinin-esterase (HE) and fusion (F) protein genes. A single amino acid change N 164 D in the putative globular head of the HE protein, and a deletion/insertion of ¡13 aa with the presence of a specific motif 352 FNT 354 in the highly polymorphic region spanning residues 337 V to M 372 in the HE protein stalk, in combination with a specific motif 265 YP 266 very close to the trypsin-cleavage site 267 RA/G 268 of the precursor F 0 protein were correlated with reduced cytopathogenicity and reduced virulence for Atlantic salmon. Phylogenetic analysis suggests that the original ancestral ISAV was virulent. The virulence of the North American genotype has not changed much, whereas the European genotype evolved into two genogroups, the real-European genogroup that is still virulent and the European-in-North America genogroup, which is of lower virulence. A novel phylogenetic software program, BACKTRACK, estimated that the North American and European genotypes diverged between 1879 and 1891, whereas the European-in-North America genogroup diverged from the real-European genogroup between 1976 and 1988. This direction of evolution supports insertion of specific motifs in the HE protein, resulting in ISAV attenuation.

Cloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chicks were examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or Erysipelothrix were isolated from the cloacal swabs. Twenty-two cloacal swabs were positive for Campylobacter, of which 14 were C. jejuni, C. coli, and 1 C. lari. None belonged to common serotypes isolated from humans or animals in recent years in Canada. Tests for antimicrobial drug resistance among 187 commensal Escherichia coli isolates from the cloacal swabs indicated that < or =5% were resistant to any of the 12 antibiotics tested. This contrasts with the frequently high resistance rates among E. coli isolates from poultry. Pharyngeal swabs from DCC were negative for Pasteurella multocida. Culture of cloacal swabs from 100 ground-nesting DCC chicks resulted in the recovery of 19 Salmonella isolates, all of which were S. enterica serotype Typhimurium. None of these isolates were resistant to any of the 12 antibiotics tested. Altogether, these findings suggest that DCC from this region are not being colonized with commensal or potentially pathogenic enteric bacteria from agricultural or human sources and that enteric bacteria isolated from these birds are unlikely to contribute to a gene pool of antimicrobial drug resistance.

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CitationHariharan H, Hariharan SH. Zoonotic bacteria associated with cats. Vet Med Open J. 2017; 2(3): 68-75. doi: 10.17140/VMOJ-2-118 ABSTRACT Background: There are several bacterial pathogens, including Bartonella, and Pasteurella that have been known to cause human infections from contact with cats. Recently, certain bacteria have emerged as causes of infection in cats, resulting in transmission to humans. Objectives: This review presents updated information on the zoonotic bacterial pathogens associated with cats, with special emphasis on recent reports. Results: Presently, an increase in the incidence of cat-associated Yersinia pestis human infections in the western USA has become a concern. In addition, infections due to Mycobacterium bovis, and Brucella abortus, are being recognized. Also, a number of human infections due to Campylobacter, Helicobacter, and Salmonella from cats have been documented worldwide. In addition, spread of bacteria resistant to antimicrobial drugs from cats is becoming a possibility. Conclusion: Updated information shows that more zoonotic bacteria than previously recognized are associated with cats worldwide. Immunocompromised persons and young children are particularly at a risk of developing infection from household cats which are allowed to roam around outdoors. It is important to incorporate environmental and animal contact considerations into patient care. With proper handling and precautions, cats can help establish valuable humananimal bonds.