Chlamydia pecorum-Associated Sporadic Ovine Abortion.

Despite previous detection of Chlamydia pecorum in sporadic ovine abortions, published descriptions of naturally occurring infections with fetoplacental lesions are lacking. This report provides the first descriptions of severe necrosuppurative chorionitis with vasculitis, and fetal pyelonephritis and enteritis in late-term abortions of maiden ewes. Chlamydial infection was detected using a Chlamydia genus-specific qPCR (quantitative polymerase chain reaction) on tissue extracts from 3 fetuses. C. pecorum was identified using a targeted qPCR assay, which also determined infectious load within fetal tissues. The presence of viable C. pecorum in fetal samples was confirmed by cell culture. Multilocus sequence typing (MLST) data indicated that the C. pecorum strains from each fetus were identical and of sequence type (ST) 23. Chlamydia sp. immunohistochemistry showed strong positive immunolabeling of fetoplacental lesions. Other infectious abortigenic agents were excluded with specific testing. This report confirms C. pecorum as a likely cause of ovine abortion and provides the first descriptions of associated fetoplacental lesions in naturally infected sheep.

Epidemiology, Clinical Signs, and Risk Factors Associated with Theileriosis in Australian Cattle (2006-2022).

For over a decade, bovine anaemia caused by Theileria orientalis Ikeda has been a significant disease in the Australian cattle industry. In this study, we conducted a spatial and temporal analysis of theileriosis in Australia using historic data from submissions to the New South Wales Department of Primary Industries (NSW DPI) from 2006 to 2022, where herd history, clinical signs, and PCR results were available. Since the first detections of bovine theileriosis in the Sydney area in 2006, the disease spread north- and southward and is now endemic to the southeast coast of Australia, closely mirroring the distribution of the principal vector Haemaphysalis longicornis. Across all years, the prevalence of the Ikeda genotype was 88%, while the prevalence of the benign Chitose and Buffeli genotypes was 55% and 38%, respectively. The majority of submissions were from beef cattle in coastal NSW, with anaemia, fever, jaundice, abortion, and lethargy the most frequently reported clinical signs. Transportation was identified as the major risk factor for disease. Until 2015, the majority of cases were reported in adult cattle, while in later years, calves made up the majority of cases, most likely due to the widespread acquisition of immunity in adults. Calves were significantly more likely to present with diarrhoea, lethargy, and anaemia, and to suffer mortality, while adults were significantly more likely to present with jaundice. Instances of abortion were observed to be significantly associated with beef cattle. The relationship between the level of parasitaemia and anaemia revealed a strong negative correlation for all animals examined.

Not gone but forgotten: Tritrichomonas foetus in extensively-managed bulls from Australia's Northern Territory.

Bovine trichomonosis, caused by infection with the protozoan parasite Tritrichomonas foetus, is globally recognised as a cause of reproductive failure in cattle. Maintained in clinically normal bulls, T. foetus infection results in infertility and abortion in infected cows. In Australia's Northern Territory (NT), logistical limitations associated with extensive livestock production inhibit wide-scale testing and diagnosis, allowing the parasite to persist undetected. In the present study, T. foetus was detected in 18/109 preputial cultures collected from bulls on a property in the NT with a history of low birth rates and reproductive failure using real-time PCR testing. Of the T. foetus-positive samples, 13/18 were genotyped using the internal transcribed spacer regions (ITS1 and ITS2) and the 5.8S rDNA unit. Selected samples were further characterised using the protein-coding genes of cysteine proteases (CP-1, 2, 4-9) and cytosolic malate dehydrogenase 1 (MDH-1) to determine if the isolates were 'bovine', 'feline' or 'Southern Africa' genotypes. All samples were 100% identical to the T. foetus 'bovine' genotype across all markers. This is the first reported case of trichomonosis in Australian cattle since 1988 and is a reminder that T. foetus should be considered whenever reproductive failure occurs in extensive cattle systems.

Chlamydia pecorum Ovine Abortion: Associations between Maternal Infection and Perinatal Mortality.

Chlamydia pecorum is a common gastrointestinal inhabitant of livestock but infections can manifest in a broad array of clinical presentations and in a range of host species. While C. pecorum is a known cause of ovine abortion, clinical cases have only recently been described in detail. Here, the prevalence and sequence types (STs) of C. pecorum in ewes from a property experiencing high levels of perinatal mortality (PNM) in New South Wales (NSW), Australia, were investigated using serological and molecular methods. Ewes that were PNM+ were statistically more likely to test seropositive compared to PNM- ewes and displayed higher antibody titres; however, an increase in chlamydial shedding from either the rectum, vagina or conjunctiva of PNM+ ewes was not observed. Multilocus sequence typing (MLST) indicated that C. pecorum ST23 was the major ST shed by ewes in the flock, was the only ST identified from the vaginal site, and was the same ST detected within aborted foetal tissues. Whole genome sequencing of C. pecorum isolated from one abortion case revealed that the C. pecorum plasmid (pCpec) contained a unique deletion in coding sequence 1 (CDS1) that was also present in C. pecorum ST23 shed from the ewes. A further unique deletion was noted in a polymorphic membrane protein gene (pmpG) of the C. pecorum chromosome, which warrants further investigation given the role of PmpG in host cell adherence and tissue tropism.This study describes novel infection parameters in a sheep flock experiencing C. pecorum-associated perinatal mortality, provides the first genomic data from an abortigenic C. pecorum strain, and raises questions about possible links between unique genetic features of this strain and C. pecorum abortion.