ORCID Profile
0000-0002-1556-9262
Current Organisation
University of Zurich
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Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.VETMIC.2011.03.040
Abstract: A substantial proportion of the causes of infectious bovine abortion remain largely undiagnosed, potentially due to the presence of previously unrecognised infectious agents. Recently, several reports have demonstrated the presence of Parachlamydia sp. in placental and foetal tissues derived from bovine abortions of unknown aetiology but the route of transmission remains undefined. The drinking water from one such recent case study was analysed for the presence of Parachlamydia sp. as a potential source of infection. Chlamydiales sp. 16S rRNA genes were PCR- lified from the drinking water and a 16S rRNA gene clone library constructed. DNA sequencing of thirty-one clones indicated the presence of organisms belonging to the Parachlamydiaceae, specifically the genera Parachlamydia and Neochlamydia. Seven 16S rRNA gene sequences were identical to a Parachlamydia sp. sequence obtained from placental tissue from an abortion case originating from the same farm. These results raise the possibility that the drinking water is a source of Parachlamydia, which may play a role in infectious bovine abortion.
Publisher: Public Library of Science (PLoS)
Date: 30-12-2019
Publisher: Microbiology Society
Date: 04-2019
DOI: 10.1099/JMM.0.000951
Abstract: Chlamydia pecorum and Chlamydia abortus are related ruminant pathogens endemic to different global regions. Potential co-infections combined with the lack of species-specific serological assays challenge accurate diagnosis. Serological screening revealed low C. abortus seropositivity with the peptide-based ELISA (1/84 1.2%) in Australian sheep yet moderate seropositivity in a Swiss flock with history of C. abortus-associated abortions (17/63 26.9%). By whole cell antigen complement fixation tests (CFT) and ELISA, chlamydial seropositivity was significantly higher in all groups, suggesting cross-reactivity between these two chlamydial species and non-specificity of the tests. However, only C. pecorum DNA could be detected by qPCR in Chlamydia seropositive Australian animals screened, suggesting chlamydial seropositivity was due to cross-reactivity with endemic C. pecorum infections. These results suggest ascribing Chlamydia seropositivity to chlamydial species in livestock using whole-cell antigen CFT or ELISA should be treated with caution and that peptide-based ELISA and qPCR provide greater chlamydial species-specificity.
Publisher: Elsevier BV
Date: 02-2019
Publisher: SAGE Publications
Date: 19-11-2021
Abstract: Chlamydia pecorum is an obligate intracellular pathogen with a wide host range including livestock such as sheep, cattle, goats, and pigs as well as wildlife species such as koalas. Chlamydial polyarthritis is an economically important disease resulting in swollen joints, lameness, stiffness, and weight loss in young sheep. In the present study, tissues from sheep experimentally or naturally infected with Chlamydia pecorum were assessed by histopathology and immunohistochemistry. Carpal, hock, and stifle joints as well as spleen, liver, kidney, lymph nodes, lung, and brain of 35 sheep from different inoculation groups were available. Two different C. pecorum strains (IPA and E58), different routes of administration (intraarticular or intravenous), UVA-irradiated IPA strain, and corresponding noninfected control groups were investigated. Similar investigations on tissues from 5 naturally infected sheep were performed. The most obvious inflammatory lesions were observed in synovial tissues and, notably, in the renal pelvis from the experimentally infected group and naturally infected animals. This resulted in chronic or chronic-active arthritis and pyelitis. Intralesional chlamydial inclusions could be demonstrated by immunohistochemistry in both tissues. Immunohistochemical evaluation of the presence and distribution of macrophages, T and B cells in synovial tissues revealed macrophages as the most prevalent inflammatory cell population. Previous observations indicated that C. pecorum isolates can infect circulating monocytes. Together with the finding of the histological lesions in synovial tissues and internal organs alongside the presence of C. pecorum DNA, these observations suggest chlamydial arthritis in lambs is the result of hematogeneous spread of C. pecorum.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2006
Publisher: MDPI AG
Date: 17-04-2020
DOI: 10.3390/ANTIBIOTICS9040187
Abstract: Due to various challenges in diagnosing chlamydiosis in pigs, antibiotic treatment is usually performed before any molecular or antibiotic susceptibility testing. This could increase the occurrence of tetracycline-resistant Chlamydia (C.) suis isolates in the affected pig population and potentiate the reoccurrence of clinical signs. Here, we present a case of an Austrian pig farm, where tetracycline resistant and sensitive C. suis isolates were isolated from four finishers with conjunctivitis. On herd-level, 10% of the finishers suffered from severe conjunctivitis and sows showed a high percentage of irregular return to estrus. Subsequent treatment of whole-herd using oxytetracycline led to a significant reduction of clinical signs. Retrospective antibiotic susceptibility testing revealed tetracycline resistance and decreased susceptibility to doxycycline in half of the ocular C. suis isolates, and all isolates were able to partially recover following a single-dose tetracycline treatment in vitro. These findings were later confirmed in vivo, when all former clinical signs recurred three months later. This case report raises awareness of tetracycline resistance in C. suis and emphasizes the importance of preventative selection of tetracycline resistant C. suis isolates.
Publisher: MDPI AG
Date: 11-08-2021
DOI: 10.3390/PATHOGENS10081015
Abstract: Chlamydia psittaci is traditionally regarded as a globally distributed avian pathogen that can cause zoonotic spill-over. Molecular research has identified an extended global host range and significant genetic ersity. However, Australia has reported a reduced host range (avian, horse, and human) with a dominance of clonal strains, denoted ST24. To better understand the widespread of this strain type in Australia, multilocus sequence typing (MLST) and ompA genotyping were applied on s les from a range of hosts (avian, equine, marsupial, and bovine) from Australia. MLST confirms that clonal ST24 strains dominate infections of Australian psittacine and equine hosts (82/88 93.18%). However, this study also found novel hosts (Australian white ibis, King parrots, racing pigeon, bovine, and a wallaby) and demonstrated that strain ersity does exist in Australia. The discovery of a C. psittaci novel strain (ST306) in a novel host, the Western brush wallaby, is the first detection in a marsupial. Analysis of the results of this study applied a multidisciplinary approach regarding Chlamydia infections, equine infectious disease, ecology, and One Health. Recommendations include an update for the descriptive framework of C. psittaci disease and cell biology work to inform pathogenicity and complement molecular epidemiology.
Publisher: Elsevier BV
Date: 05-2021
No related grants have been discovered for Nicole Borel.