Evidence of bromethalin toxicosis in feral San Francisco "Telegraph Hill" conures.

During 2018, four free-ranging conures, from a naturalized flock in San Francisco, presented with a characteristic set of neurologic signs that had been reported in other individuals from this flock. The cause of morbidity or mortality in historic cases has not been identified. From these four subjects, fresh feces were collected during their initial days of hospitalization and submitted to the University of Georgia Infectious Diseases Laboratory and Center for Applied Isotope Studies for bromethalin and desmethyl-bromethalin quantitation. Using High Performance Liquid Chromatography, the laboratory detected bromethalin, a non-anticoagulant, single-dose rodenticide, in fecal samples from three subjects; half of these samples were also positive for desmethyl-bromethalin, bromethalin's active metabolite. In three subjects that died, the UGA laboratory screened brain and liver samples and found bromethalin in all samples; desmethyl-bromethalin was detected in all but one brain sample, which was below the detection limit. Our findings suggest the conures are more resistant to bromethalin than are other species in which bromethalin has been studied, and/or that the conures may be ingesting the toxin at a sublethal dose. More data is needed to better assess the long-term effects of bromethalin on animals exposed at the subacute/chronic levels, and also to better understand the compartmentalization of bromethalin and desmethyl-bromethalin in a wider variety of species.

CHLAMYDIA PSITTACI IN FERAL ROSY-FACED LOVEBIRDS ( AGAPORNIS ROSEICOLLIS) AND OTHER BACKYARD BIRDS IN MARICOPA COUNTY, ARIZONA, USA.

In 2013, a mortality event of nonnative, feral Rosy-faced Lovebirds ( Agapornis roseicollis) in residential backyards in Maricopa County, Arizona, US was attributed to infection with Chlamydia psittaci. In June 2014, additional mortality occurred in the same region. Accordingly, in August 2014 we sampled live lovebirds and sympatric bird species visiting backyard bird feeders to determine the prevalence of DNA and the seroprevalence of antibodies to C. psittaci using real-time PCR-based testing and elementary body agglutination, respectively. Chlamydia psittaci DNA was present in conjunctival-choanal or cloacal swabs in 93% (43/46) of lovebirds and 10% (14/142) of sympatric birds. Antibodies to C. psittaci were detected in 76% (31/41) of lovebirds and 7% (7/102) of sympatric birds. Among the sympatric birds, Rock Doves ( Columba livia) had the highest prevalence of C. psittaci DNA (75%; 6/8) and seroprevalence (25%; 2/8). Psittacine circovirus 1 DNA was also identified, using real-time PCR-based testing, from the same swab samples in 69% (11/16) of species sampled, with a prevalence of 80% (37/46) in lovebirds and 27% (38/142) in sympatric species. The presence of either Rosy-faced Lovebirds or Rock Doves at residential bird feeders may be cause for concern for epizootic and zoonotic transmission of C. psittaci in this region.

Genotyping of Chlamydophila psittaci by real-time PCR and high-resolution melt analysis.

Human infection with Chlamydophila (Chlamydia) psittaci can lead to psittacosis, a disease that occasionally results in severe pneumonia and other medical complications. C. psittaci is currently grouped into seven avian genotypes: A through F and E/B. Serological testing, outer membrane protein A (ompA) gene sequencing, and restriction fragment length polymorphism analysis are currently used for distinguishing these genotypes. Although accurate, these methods are time-consuming and require multiple confirmatory tests. By targeting the ompA gene, a real-time PCR assay has been developed to rapidly detect and genotype C. psittaci by light-upon-extension chemistry and high-resolution melt analysis. Using this assay, we screened 169 animal specimens; 98 were positive for C. psittaci (71.4% genotype A, 3.1% genotype B, 4.1% genotype E, and 21.4% unable to be typed). This test may provide insight into the distribution of each genotype among specific hosts and provide epidemiological and epizootiological data in human and mammalian/avian cases. This diagnostic assay may also have veterinary applications during chlamydial outbreaks, particularly with respect to identifying the sources and tracking the movements of a particular genotype when multiple animal facilities are affected.