Dissemination and genetic diversity of chlamydial agents in Polish wildfowl: Isolation and molecular characterisation of avian Chlamydia abortus strains

Abstract

Wild birds are considered as a reservoir for avian chlamydiosis posing a potential infectious threat to domestic poultry and humans. Analysis of 894 cloacal or fecal swabs from free-living birds in Poland revealed an overall Chlamydiaceae prevalence of 14.8% (n = 132) with the highest prevalence noted in Anatidae (19.7%) and Corvidae (13.4%). Further testing conducted with species-specific real-time PCR showed that 65 samples (49.2%) were positive for C. psittaci whereas only one was positive for C. avium. To classify the non-identified chlamydial agents and to genotype the C. psittaci and C. avium-positive samples, specimens were subjected to ompA-PCR and sequencing (n = 83). The ompA-based NJ dendrogram revealed that only 23 out of 83 sequences were assigned to C. psittaci, in particular to four clades representing the previously described C. psittaci genotypes B, C, Mat116 and 1V. Whereas the 59 remaining sequences were assigned to two new clades named G1 and G2, each one including sequences recently obtained from chlamydiae detected in Swedish wetland birds. G1 (18 samples from Anatidae and Rallidae) grouped closely together with genotype 1V and in relative proximity to several C. abortus isolates, and G2 (41 samples from Anatidae and Corvidae) grouped closely to C. psittaci strains of the classical ABE cluster, Matt116 and M56. Finally, deep molecular analysis of four representative isolates of genotypes 1V, G1 and G2 based on 16S rRNA, IGS and partial 23S rRNA sequences as well as MLST clearly classify these isolates within the C. abortus species. Consequently, we propose an expansion of the C. abortus species to include not only the classical isolates of mammalian origin, but also avian isolates so far referred to as atypical C. psittaci or C. psittaci/C. abortus intermediates.

Poultry in Poland as Chlamydiaceae carrier

“…The two C. psittaci sequences from our study (15-41 and 15-63) represented genotype C that is typical for poultry. Interestingly, these sequences grouped together with a sequence obtained earlier by our research group from a swan in Poland (KX062086.1) ( 30 ). This is a clear indication of transmission of C. psittaci between wild and domestic birds.…”

“…turkey, budgerigar, oriental white stork, and pigeon ( 3 , 25 , 28 ). C. abortus has attracted increasing scientific attention due to its pathogenicity and several events of systemic infection in humans ( 2 , 9 , 16 , 21 , 35 , 36 ), as well as the isolation of the agent from new hosts including birds ( 30 ). Therefore, Pannekoek et al .…”

“…Blood samples (n = 500) were taken from humans in two sampling groups: control and study (see Supplementary file S2). The first group consisted of randomly selected blood donors (n = 250) and the second group consisted of individuals who declared contact with birds (n = 250), including persons with occupational exposure on poultry farms (n = 215), as well as veterinarians (n = 20) and ornithologists (n = 15) involved in handling wild birds ( 30 ). None of the persons tested reported any clinical symptoms at the time of interview.…”

Molecular evidence to suggest pigeon-type Chlamydia psittaci in association with an equine foal loss

“…This was a surprising finding given the previous report (Jelocnik et al., ) and our own ongoing surveillance of additional equine reproductive loss cases (Jenkins et al., submitted) detecting only parrot‐like C. psittaci strains (ST24 and omp A genotype “A”). OmpA genotype B strains are responsible for up to 50% of infections in C. psittaci ‐infected feral pigeons in Europe (Magnino et al., ; Sachse, Kuehlewind, Ruettger, Schubert, & Rohde, ), although they can also be detected in non‐ Columbidae family species (Szymanska‐Czerwinska et al., ). Chlamydia psittaci infections in feral pigeons are particularly prevalent with both PCR and serology studies reporting high prevalence percentages across European countries where surveillance has been performed (Magnino et al., ; Sachse et al., ).…”

Evidencia de Chlamydia no psittaci en psitácidos en cautiverio de Venezuela

“…Nuevamente fue identificado en aves de centros de rehabilitación un nuevo genotipo de Chlamydia que al estudio filogenético se encuentra más próximo a C. abortus. De esta forma, proponen que esta especie, además que ser aislada en mamíferos, debe ser reconocida como causante de infecciones atípicas en aves (24).…”