Chlamydia buteonis in birds of prey presented to California wildlife rehabilitation facilities

PLoS One. 2021 Oct 13;16(10):e0258500. doi: 10.1371/journal.pone.0258500. eCollection 2021.

Abstract

Chlamydial infections, caused by a group of obligate, intracellular, gram-negative bacteria, have health implications for animals and humans. Due to their highly infectious nature and zoonotic potential, staff at wildlife rehabilitation centers should be educated on the clinical manifestations, prevalence, and risk factors associated with Chlamydia spp. infections in raptors. The objectives of this study were to document the prevalence of chlamydial DNA shedding and anti-chlamydial antibodies in raptors admitted to five wildlife rehabilitation centers in California over a one-year period. Chlamydial prevalence was estimated in raptors for each center and potential risk factors associated with infection were evaluated, including location, species, season, and age class. Plasma samples and conjunctiva/choana/cloaca swabs were collected for serology and qPCR from a subset of 263 birds of prey, representing 18 species. Serologic assays identified both anti-C. buteonis IgM and anti-chlamydial IgY antibodies. Chlamydial DNA and anti-chlamydial antibodies were detected in 4.18% (11/263) and 3.14% (6/191) of patients, respectively. Chamydial DNA was identified in raptors from the families Accipitridae and Strigidae while anti-C.buteonis IgM was identified in birds identified in Accipitridae, Falconidae, Strigidae, and Cathartidae. Two of the chlamydial DNA positive birds (one Swainson's hawk (Buteo swainsoni) and one red-tailed hawk (Buteo jamaicensis)) were necropsied, and tissues were collected for culture. Sequencing of the cultured elementary bodies revealed a chlamydial DNA sequence with 99.97% average nucleotide identity to the recently described Chlamydia buteonis. Spatial clusters of seropositive raptors and raptors positive for chlamydial DNA were detected in northern California. Infections were most prevalent during the winter season. Furthermore, while the proportion of raptors testing positive for chlamydial DNA was similar across age classes, seroprevalence was highest in adults. This study questions the current knowledge on C. buteonis host range and highlights the importance of further studies to evaluate the diversity and epidemiology of Chlamydia spp. infecting raptor populations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild
  • Antibodies, Bacterial / blood
  • Bird Diseases / epidemiology*
  • Bird Diseases / immunology
  • Bird Diseases / microbiology
  • California / epidemiology
  • Chlamydia / classification
  • Chlamydia / genetics
  • Chlamydia / immunology
  • Chlamydia / isolation & purification*
  • Chlamydia Infections / epidemiology*
  • Chlamydia Infections / immunology
  • Chlamydia Infections / microbiology
  • Cloaca / microbiology
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • Immunoglobulin M / blood
  • Immunoglobulins / blood
  • Phylogeny
  • Prevalence
  • Raptors / microbiology*
  • Rehabilitation Centers
  • Risk Factors
  • Sequence Analysis, DNA

Substances

  • Antibodies, Bacterial
  • DNA, Bacterial
  • IgY
  • Immunoglobulin M
  • Immunoglobulins

Supplementary concepts

  • Chlamydia buteonis

Grants and funding

This study was financially supported through the Karen C. Drayer Wildlife Health Center Fellowship Grant Program, School of Veterinary Medicine, Univ. of California, Davis, Davis, CA and the Infectious Disease Laboratory, College of Veterinary Medicine, University of Georgia, Athens, GA. The Karen C. Drayer Wildlife Health Center funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The Infectious Disease Laboratory, University of GA donated the costs of the qPCR testing, EBA testing and chlamydial cultures and were instrumental in data analysis, decision to publish and preparation of the manuscript. Multiple authors are affiliated with the laboratory (Ritchie, Nilsen, Ciembor, Pesti, Gregory) but only Ritchie and Nilsen were involved in manuscript preparation.