Occurrence of Chlamydiaceae in Raptors and Crows in Switzerland

Abstract

Bacteria of the family Chlamydiaceae are globally disseminated and able to infect many bird species. So far, 11 species of Chlamydia have been detected in wild birds, and several studies found chlamydial strains classified as genetically intermediate between Chlamydia (C.) psittaci and C.abortus. Recently, a group of these intermediate strains was shown to form a separate species, i.e., C.buteonis. In the present study, 1128 samples from 341 raptors of 16 bird species and 253 corvids representing six species were examined using a stepwise diagnostic approach. Chlamydiaceae DNA was detected in 23.7% of the corvids and 5.9% of the raptors. In corvids, the most frequently detected Chlamydia species was C.psittaci of outer membrane protein A (ompA) genotype 1V, which is known to have a host preference for corvids. The most frequently detected ompA genotype in raptors was M56. Furthermore, one of the raptors harbored C.psittaci 1V, and two others carried genotype A. C.buteonis was not detected in the bird population investigated, so it remains unknown whether this species occurs in Switzerland. The infection rate of Chlamydiaceae in corvids was high compared to rates reported in other wild bird species, but neither Chlamydiaceae-positive corvids nor raptors showed overt signs of disease. Since the Chlamydiaceae of both, raptors and crows were identified as C.psittaci and all C.psittaci genotypes are considered to be zoonotic, it can be suggested that raptors and crows pose a potential hazard to the health of their handlers.

Occurrence of Chlamydiaceae and Chlamydia felis pmp9 Typing in Conjunctival and Rectal Samples of Swiss Stray and Pet Cats

“…Initially, all 954 samples were screened with the 23S rRNA-based Chlamydiaceae family-specific real-time PCR [ 77 ]. The qPCR was carried out with the ABI 7500 Fast Real-time PCR System (Thermo Fisher Scientific, Waltham, MA, USA) including an internal amplification control based on enhanced green fluorescent protein (eGFP) DNA as previously described [ 68 , 78 , 79 , 80 , 81 ]. Cycling conditions were set to 95 °C for 20 s, followed by 45 cycles of 95 °C for 3 s, and 60 °C for 30 s. Samples with DNA concentrations above 150 ng/μL were diluted 10-fold, and all samples and dilutions were tested in duplicates.…”

A Review of Chlamydial Infections in Wild Birds

“…Genotype A has been isolated from a diverse range of wild hosts, including parrots (e.g., crimson rosellas ( Platycercus elegans ) and galahs ( Eolophus roseicapillus )) [ 32 , 33 ], passerines (including robins ( Erithacus rubecula ), dunnocks ( Prunella modularis ) and great tits ( Parus major )), raptors (including Eurasian sparrowhawks ( Accipiter nisus ) and common buzzards ( Buteo buteo )) [ 34 ], and fulmars ( Fulmarus glacialis ) [ 30 , 35 ]. The more recently proposed genotype 1V appears to be associated with the Corvidae family [ 34 , 36 ]. Interestingly, genotype M56 (originally associated with mammals) has recently been found in association with wild raptors [ 34 , 37 ] in Switzerland and the USA.…”

“…The more recently proposed genotype 1V appears to be associated with the Corvidae family [ 34 , 36 ]. Interestingly, genotype M56 (originally associated with mammals) has recently been found in association with wild raptors [ 34 , 37 ] in Switzerland and the USA.…”

“…Chlamydiaceae have been found in a wide variety of other wild bird species and appear to be fairly prevalent in birds in the Anatidae (duck) family (19.7–58.0%), where Chlamydiaceae have been identified in at least five different species [ 12 , 29 , 73 ] and the Corvidae (crow) family (13.4–23.7%) where Chlamydiaceae have been isolated from at least six species [ 29 , 34 , 36 ]. Many seabirds are also infected, with Chlamydiaceae detected in at least seven different species from three different families, including the Laridae (gulls; prevalence of up to 13.6% in European herring gull ( Larus argentatus )), Sulidae (gannets and boobies; up to 41.3% in the Northern gannet ( Morus bassanus ) [ 12 ]) and the Procellariidae (fulmars; where prevalence is up to 21% according to location [ 74 ]).…”

“…Both the Anatidae and Corvidae families can have C. psittaci infections [ 12 , 29 ], and several seabird species, including fulmars, black-headed gulls ( Chroicocephalus ridibundus ), and Northern gannets, have been found infected with C. psittaci and C. psittaci related strains [ 12 , 57 , 74 ]. The Anatidae, Corvidae, and Laridae have also been reported with C. abortus and non-classified Chlamydia infections [ 29 , 34 ], and the Gruiformes (specifically, Eurasian coots ( Fulica atra )) have tested positive for C. trachomatis [ 52 ]). Raptors within the Accipitridae family are increasingly being tested for chlamydial bacteria and have tested positive for C. psittaci , the novel C. buteonis , and for novel CRB [ 5 , 75 , 76 ].…”