Haemophilus somnus (Histophilus somni) in bighorn sheep.

University of Idaho, College of Agriculture, Caine Veterinary Teaching Center, 1020 East Homedale Road, Caldwell, Idaho 83607-8098, USA.
Canadian journal of veterinary research = Revue canadienne de recherche vétérinaire (Impact Factor: 0.85). 02/2006; 70(1):34-42.
Source: PubMed

ABSTRACT Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host-parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Multiple determinants have been hypothesized to cause or favor disease outbreaks among free-ranging bighorn sheep (Ovis canadensis) populations. This paper considered direct and indirect causes of mortality, as well as potential interactions among proposed environmental, host, and agent determinants of disease. A clear, invariant relationship between a single agent and field outbreaks has not yet been documented, in part due to methodological limitations and practical challenges associated with developing rigorous study designs. Therefore, although there is a need to develop predictive models for outbreaks and validated mitigation strategies, uncertainty remains as to whether outbreaks are due to endemic or recently introduced agents. Consequently, absence of established and universal explanations for outbreaks contributes to conflict among wildlife and livestock stakeholders over land use and management practices. This example illustrates the challenge of developing comprehensive models for understanding and managing wildlife diseases in complex biological and sociological environments.
    03/2012; 2012:796527. DOI:10.1155/2012/796527
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A study was conducted to isolate bacterial species/pathogens from the nasal cavity of apparently healthy and pneumonic sheep. Nasal swabs were collected aseptically, transported in tryptose soya broth and incubated for 24 h. Then, each swab was streaked onto chocolate and blood agar for culture. Bacterial species were identified following standard bacteriological procedures. Accordingly, a total of 1,556 bacteria were isolated from 960 nasal swabs collected from three different highland areas of Ethiopia, namely Debre Berhan, Asella, and Gimba. In Debre Berhan, 140 Mannheimia haemolytica, 81 Histophilus somni, 57 Staphylococcus species, and 52 Bibersteinia trehalosi were isolated. While from Gimba M. haemolytica, Staphylococcus, Streptococcus, and H. somni were isolated at rates of 25.2, 15.9, 11.4, and 5.9 %, respectively, of the total 647 bacterial species. In Asella from 352 bacterial species isolated, 93 (26.4 %) were M. haemolytica, 48 (13.6 %) were Staphylococcus species, 26 (7.4 %) were B. trehalosi, and 17 (4.8 %) H. somni were recognized. Further identification and characterization using BIOLOG identification system Enterococcus avium and Sphingomonas sanguinis were identified at 100 % probability, while, H. somni and Actinobacillus lignerisii were suggested by the system. The study showed that a variety of bacterial species colonize the nasal cavity of the Ethiopian highland sheep with variable proportion between healthy and pneumonic ones. To our knowledge, this is the first report on isolation of H. somni, an important pathogen in cattle, from the respiratory tract of a ruminant species in the country.
    Tropical Animal Health and Production 01/2013; 45(5). DOI:10.1007/s11250-013-0355-x · 0.97 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The numbers of potentially pathogenic microorganisms that have been isolated from stranded cetaceans in the last three decades underscore the urgent need for methods of detection of microorganisms that might cause significant disease and increase the likelihood of population declines. We have designed and implemented two non-invasive techniques for the collection of exhaled breath condensate (blow) from free-ranging whales and demonstrated their suitability for the detection of respiratory bacteria. We successfully collected 22 individual blow samples from eight cetacean species. Using well-established molecular techniques we detected three bacterial genera (Haemophilus, Streptococcus and Staphylococcus). Haemophilus spp. was detected in fin whale Balaenoptera physalus, sperm whale Physeter macrocephalus, humpback whale Megaptera novaeangliae and gray whale Eschrichtius robustus blows, while unidentified β-hemolytic streptococci and Staphylococcus aureus were detected in gray whale and blue whale Balaenoptera musculus blows. The detection limit of the test was determined as 1 CFU mL−1. None of the identified bacteria were found in environmental (control) samples, suggesting that their presence in the blows was genuine and not due to inadvertent contamination. While the population-level relevance of these bacteria is as yet unclear and it is possible that they are commensal microorganisms, S. aureus has been identified previously as a high-risk pathogen to cetacean health, and streptococci have increasingly been associated with cetacean mortality events. We suggest that future cetacean monitoring programs of vulnerable or threatened species include blow sampling as a means to determine the prevalence of the respiratory bacteria in the populations and monitor spatiotemporal fluctuations as indicators of changes in cetacean health.
    Animal Conservation 11/2009; 13(2):217 - 225. DOI:10.1111/j.1469-1795.2009.00326.x · 2.52 Impact Factor

Full-text (2 Sources)

Available from
May 22, 2014