ATYPICAL CHLAMYDIACEAE IN WILD POPULATIONS OF HAWKS ( BUTEO SPP.) IN CALIFORNIA

Area of Science:

• Veterinary Microbiology
• Wildlife Disease Ecology
• Avian Pathology

Background:

• Chlamydiaceae infections are common in vertebrates, with prevalence in wild birds often assessed using PCR and serology.
• Previous diagnostic methods for Chlamydia spp. in wild raptors are prone to cross-reactivity, potentially leading to inaccurate prevalence estimates.
• Understanding Chlamydiaceae prevalence and diversity in wild raptor populations is crucial for assessing potential health impacts.

Purpose of the Study:

• To determine the prevalence of Chlamydiaceae DNA in wild Buteo hawks in California using a quantitative PCR (qPCR) assay.
• To characterize any detected Chlamydiaceae DNA, particularly focusing on novel or atypical genotypes.
• To investigate the potential presence of Chlamydiaceae infections in wild hawk populations that may differ from known avian strains.

Main Methods:

• Collected multimucosal swab samples (n=291) and plasma (n=78) from wild hawks in California.
• Utilized quantitative PCR (qPCR) for Chlamydiaceae DNA detection in swab samples.
• Performed serological testing on plasma samples using a Chlamydia psittaci-specific elementary body agglutination test (EBA) and an indirect immunofluorescent assay for IgY antibodies.
• Sequenced the ompA gene of positive samples and compared them to known Chlamydiaceae sequences using high-resolution melt analysis.

Main Results:

• Chlamydiaceae DNA was detected in 1.37% (4/291) of the wild Buteo hawks sampled.
• All plasma samples tested negative for Chlamydia psittaci antibodies.
• The qPCR-positive samples contained an atypical Chlamydiaceae sequence, most closely related (98.6%) to Chlamydia psittaci M56, a genotype typically found in mammals.
• The detected sequence did not fully match any known avian Chlamydiaceae genotypes.

Conclusions:

• A low prevalence of Chlamydiaceae DNA was found in wild California Buteo hawks.
• An atypical Chlamydiaceae sequence, with mammalian origins, was identified in four hawks, suggesting a potential novel pathogen or strain in this population.
• Further research, including bacterial culture and whole-genome sequencing, is needed to classify this organism and understand its epizootiology and impact on wild raptor health.