Med. Weter. 68 (6), 328-332, 2012

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Niemczuk K., Truszczyński M.
Pathogenicity of Chlamydiaceae with particular reference to cattle
This article discusses different effects of pathogenicity of Chlamydiaceae in animals, with particular reference to cattle. The pathogenicity for humans is mentioned as well. It is pointed out that chlamydioses caused by individual species of Chlamydiaceae are avian chlamydiosis, caused by Chlamydophila psittaci, ovine chlamydiosis, caused by Chlamydophila abortus, and trachoma in humans, caused by Chlamydia tra-chomatis. More often these and other species of Chlamydiaceae are involved in mixed infections with other facultatively pathogenic microorganisms in different species of animals, such as cattle (including calves), causing respiratory disorders, enteritis, abortion, mastitis, polyarthritis, and encephalomyelitis. Subclinical infections in which Chlamydiaceae behave as commensals occur rather frequently. Since diagnosis of chlamydial infections requires the application of laboratory assays, the article presents and evaluates selective modern tests for the identification of microorganisms or specific antibodies, particularly ELISA and RT-PCR. Serological detection has been found more suitable for prevalence surveys than for retrospective diagnosis of chlamydial infection. Chlamydophile psittaci followed by Chlamydophila abortus and Chlamydphila pecorum are mentioned as the most prevalent representative species of Chlamydiaceae in cattle. Fecal shedding of Chlamydiaceae by carrier animals is thought to be the most important way of spreading the infection. In most cases in which pathological syndromes are observed in cattle, representatives of Chlamydiaceae are among several factors in a polyetiological complex, which also includes other species of microorganisms and unfavourable environmental conditions. Therefore, an improvement in herd management, and especially in the housing and nutrition of animals, is of primary importance for the control of chlamydial infections. There is no evidence of a successful use of antimicrobials in the elimination of bovine chlamydial infection. The use of vaccines is recommended. Their efficacy, however, needs to be improved.
Keywords: chlamydiosis, chlamydial infection, multifactorial etiology, cattle