Faculty of Veterinary Medicine University of Zagreb
Abstract
In this investigation fecal samples from a total of 232 homing pigeon lofts, belonging to both racing and breeding pigeons, were examined by specific real-time PCR to reveal the presence of Chlamydiaceae, and randomly collected Chlamydia positive samples were genotyped by two different molecular methods; C. psittaci-specific restriction fragment length polymorphism (RFLP) and Multiple-Locus Variable number tandem repeat Analysis (MLVA), in order to obtain relevant information about the prevalence of different genotypes, and to reveal the potential threat to humans that come into close contact with homing pigeons. Chlamydiosis in birds manifests as an acute, unapparent, sub-clinical, and chronic disease, but frequently also as an asymptomatic infection, which represents an additional danger for public health. Currently, nine different genotypes of C. psittaci have been generally accepted, based on PCR amplification, as well as an additional six provisional genotypes, based on DNA microarray. The predominant serotype/genotype in pigeons is B, but also other genotypes were discovered, such as A, C and D, as well as mixed infection. Out of 232 examined samples, 30 (12.9%) of them were PCR positive. DNA from six random positive fecal samples was further examined and the presence of C. psittaci was confirmed in all of them. According to RFLP genotyping, from 6 C. psittaci positive samples, 4 of them belonged to genotype B, and 2 strains remained untyped, due to the low concentration of DNA isolated. Regarding the MLVA typing, the pattern assigned as 22146334 could be described as a classical “pigeon” MLVA pattern. The presence of 12.9% homing pigeons positive to Chlamydiaceae by PCR clearly demonstrates the presence of zoonotic microorganisms and a possible risk for pigeon fanciers that come in close contact with the birds.Ukupno su bila pretražena 232 uzorka izmeta golubova na prisutnost bakterija porodice Chlamydiaceae pomoću za Chlamydiaceae specifične lančane reakcije polimerazom u stvarnom vremenu. Nasumično odabrani pozitivni uzorci pretraženi su i na prisutnost bakterije Chlamydia psittaci (C. psittaci), te su u slučaju pozitivnog nalaza i genotipizirani pomoću dvije različite molekularne metode - MLVA i RFLP, kako bi dobili svrsishodne informacije o učestalosti različitih genotipova, te otkrili potencijalnu prijetnju za zdravlje ljudi koji dolaze u bliži kontakt s golubovima. Klamidioza u ptica očituje se kao akutna, inaparentna, supklinička ili kronična bolest, ali često i kao asimptomatska zaraza, što predstavlja dodatnu opasnost za javno zdravstvo. Novijim istraživanjima, temeljenim na lančanoj reakciji polimerazom (PCR) nađeno je devet različitih genotipova C. psittaci. Prevladavajući serotip/genotip u golubova je B, ali su u njih nađeni i drugi genotipovi, kao što su A, C i D, te mješovite infekcije. Od 232 pregledana uzorka, njih 30 (12,9%) bilo je pozitivno na prisutnost bakterija iz porodice Chlamydiaceae. Nasumično izabrana DNK šest pozitivnih uzoraka dodatno je pretražena i na prisutnost C. psittaci, te je nalaz bio pozitivan u svih šest uzoraka. Pomoću PCR-RFLP metode, od 6 uzoraka pozitivnih na bakteriju C. psittaci, četiri su pripadala genotipu B, dok se dva uzorka nisu mogla pretražiti zbog niske koncentracije izdvojene DNK. Pomoću MLVA metode, četiri pretražena uzorka označena su oznakom 22146334, što se opisuje kao “golublji” genotip. Nalaz 12,9% golubova pozitivnih na prisutnost bakterija porodice Chlamydiaceae jasno pokazuje prisutnost uzročnika u jatima golubova u Hrvatskoj, te mogući rizik za uzgajivače koji dolaze u bliski kontakt s pticama
