Safety and Immunogenicity of a Mycoplasma ovipneumoniae Bacterin for Domestic Sheep (Ovis aries)

Ziegler, Jessie; Lahmers, Kevin K.; Barrington, George M.; Parish, Steven M.; Kilzer, Katherine; Baker, Katherine N. K.; Besser, Thomas E.

doi:10.1371/journal.pone.0095698

Cited by 41 publications

(53 citation statements)

References 26 publications

(46 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…() and Ziegler et al . (), respectively. Both tests were used to ascribe infection status to a sample, and RT‐PCR was also used to estimate relative pathogen load.…”

Section: Methodsmentioning

confidence: 95%

“…We collected nasal samples with dacron swabs and placed these samples into mycoplasma broth (Hardy Diagnostics, Santa Maria, CA) for culture enrichment or into sterile tubes (dry swabs). We conducted PCR and RT-PCR (realtime PCR) detection of M. ovipneumoniae with the methods described in McAuliffe et al (2003) and Ziegler et al (2014), respectively. Both tests were used to ascribe infection status to a sample, and RT-PCR was also used to estimate relative pathogen load.…”

Section: Sampling Methods and Diagnostic Testingmentioning

confidence: 99%

See 1 more Smart Citation

Age‐specific infectious period shapes dynamics of pneumonia in bighorn sheep

et al. 2017

Self Cite

View full text Add to dashboard Cite

Superspreading, the phenomenon where a small proportion of individuals contribute disproportionately to new infections, has profound effects on disease dynamics. Superspreading can arise through variation in contacts, infectiousness or infectious periods. The latter has received little attention, yet it drives the dynamics of many diseases of critical public health, livestock health and conservation concern. Here, we present rare evidence of variation in infectious periods underlying a superspreading phenomenon in a free-ranging wildlife system. We detected persistent infections of Mycoplasma ovipneumoniae, the primary causative agent of pneumonia in bighorn sheep (Ovis canadensis), in a small number of older individuals that were homozygous at an immunologically relevant genetic locus. Interactions among age-structure, genetic composition and infectious periods may drive feedbacks in disease dynamics that determine the magnitude of population response to infection. Accordingly, variation in initial conditions may explain divergent population responses to infection that range from recovery to catastrophic decline and extirpation.

show abstract

“…() and Ziegler et al . (), respectively. Both tests were used to ascribe infection status to a sample, and RT‐PCR was also used to estimate relative pathogen load.…”

Section: Methodsmentioning

confidence: 95%

Section: Sampling Methods and Diagnostic Testingmentioning

confidence: 99%

Age‐specific infectious period shapes dynamics of pneumonia in bighorn sheep

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

“…We extracted DNA from a subset of these sources to detect and strain type M. ovipneumoniae within the study population and the metapopulation through time. Detection was based on conventional (McAuliffe et al 2003) and realtime (Ziegler et al 2014) PCR. We used multi-locus sequence typing (MLST) to characterize strains using partial DNA sequences of the 16S-23S intergenic spacer region (IGS), the small ribosomal subunit (16S), and the genes encoding RNA polymerase B (rpoB) and gyrase B (gyrB).…”

Section: Strain Typingmentioning

confidence: 99%

Evidence for strain‐specific immunity to pneumonia in bighorn sheep

et al. 2016

Self Cite

View full text Add to dashboard Cite

Transmission of pathogens commonly carried by domestic sheep and goats poses a serious threat to bighorn sheep (Ovis canadensis) populations. All‐age pneumonia die‐offs usually ensue, followed by asymptomatic carriage of Mycoplasma ovipneumoniae by some of the survivors. Lambs born into these chronically infected populations often succumb to pneumonia, but adults are usually healthy. Surprisingly, we found that introduction of a new genotype (strain) of M. ovipneumoniae into a chronically infected bighorn sheep population in the Hells Canyon region of Washington and Oregon was accompanied by adult morbidity (100%) and pneumonia‐induced mortality (33%) similar to that reported in epizootics following exposure of naïve bighorn sheep. This suggests an immune mismatch occurred that led to ineffective cross‐strain protection. To understand the broader context surrounding this event, we conducted a retrospective analysis of M. ovipneumoniae strains detected in 14 interconnected populations in Hells Canyon over nearly 3 decades. We used multi‐locus sequence typing of DNA extracts from 123 upper respiratory tract and fresh, frozen, and formalin‐fixed lung samples to identify 5 distinct strains of M. ovipneumoniae associated with all‐age disease outbreaks between 1986 and 2014, a pattern consistent with repeated transmission events (spillover) from reservoir hosts. Phylogenetic analysis showed that the strain associated with the outbreak observed in this study was likely of domestic goat origin, whereas strains from other recent disease outbreaks probably originated in domestic sheep. Some strains persisted and spread across populations, whereas others faded out or were replaced. Lack of cross‐strain immunity in the face of recurrent spillovers from reservoir hosts may account for a significant proportion of the disease outbreaks in bighorn sheep that continue to happen regularly despite a century of exposure to domestic sheep and goats. Strain‐specific immunity could also complicate efforts to develop vaccines. The results of our study support existing management direction to prevent contacts that could lead to pathogen transmission from domestic small ruminants to wild sheep, even if the wild sheep have previously been exposed. Our data also show that under current management, spillover is continuing to occur, suggesting that enhanced efforts are indicated to avoid introducing new strains of M. ovipneumoniae into wild sheep populations. We recommend looking for new management approaches, such as clearing M. ovipneumoniae infection from domestic animal reservoirs in bighorn sheep range, and placing greater emphasis on existing strategies to elicit more active cooperation by the public and to increase vigilance on the part of resource managers. © 2016 The Wildlife Society.

show abstract

“…Nasal swabs were obtained from most (82 of 129, accounting for 74% of all observations) of the marked animals in the winter preceding summer observations. Samples were analysed at the Washington Disease Diagnostic Laboratory, who measured per cent inhibition by an anti-M. ovi antibody using a competitive ELISA, and identified active current infections on a categorical basis (an animal was infected or not) using real-time M. ovi-specific PCR (Ziegler et al 2014). We assume PCR status during the preceding winter was a reasonable proxy for an active infection throughout this manuscript.…”

Section: Materials and Methods Study Populations And Field Data Collementioning

confidence: 99%

Contact and contagion: Probability of transmission given contact varies with demographic state in bighorn sheep

Manlove

Cassirer

Plowright

et al. 2017

Journal of Animal Ecology

View full text Add to dashboard Cite

Understanding both contact and probability of transmission given contact are key to managing wildlife disease. However, wildlife disease research tends to focus on contact heterogeneity, in part because the probability of transmission given contact is notoriously difficult to measure. Here, we present a first step towards empirically investigating the probability of transmission given contact in free-ranging wildlife.We used measured contact networks to test whether bighorn sheep demographic states vary systematically in infectiousness or susceptibility to Mycoplasma ovipneumoniae, an agent responsible for bighorn sheep pneumonia.We built covariates using contact network metrics, demographic information and infection status, and used logistic regression to relate those covariates to lamb survival. The covariate set contained degree, a classic network metric describing node centrality, but also included covariates breaking the network metrics into subsets that differentiated between contacts with yearlings, ewes with lambs, and ewes without lambs, and animals with and without active infections.Yearlings, ewes with lambs, and ewes without lambs showed similar group membership patterns, but direct interactions involving touch occurred at a rate two orders of magnitude higher between lambs and reproductive ewes than between any classes of adults or yearlings, and one order of magnitude higher than direct interactions between multiple lambs.Although yearlings and non-reproductive bighorn ewes regularly carried M. ovipneumoniae, our models suggest that a contact with an infected reproductive ewe had approximately five times the odds of producing a lamb mortality event of an identical contact with an infected dry ewe or yearling. Consequently, management actions targeting infected animals might lead to unnecessary removal of young animals that carry pathogens but rarely transmit.This analysis demonstrates a simple logistic regression approach for testing a priori hypotheses about variation in the odds of transmission given contact for free-ranging hosts, and may be broadly applicable for investigations in wildlife disease ecology.

show abstract

Safety and Immunogenicity of a Mycoplasma ovipneumoniae Bacterin for Domestic Sheep (Ovis aries)

Cited by 41 publications

References 26 publications

Age‐specific infectious period shapes dynamics of pneumonia in bighorn sheep

Age‐specific infectious period shapes dynamics of pneumonia in bighorn sheep

Evidence for strain‐specific immunity to pneumonia in bighorn sheep

Contact and contagion: Probability of transmission given contact varies with demographic state in bighorn sheep

Contact Info

Product

Resources

About