Meningoencephalitis, Vasculitis, and Abortions Caused by Chlamydia pecorum in a Herd of Cattle

Abstract

A cow dairy ( n = 2000) in close proximity to a sheep flock had third-trimester abortions and fatalities in cows and calves over a 14-month period. Eighteen of 33 aborted fetuses (55%) had multifocal random suppurative or mononuclear meningoencephalitis with vasculitis. Seventeen of these affected fetuses had intracytoplasmic bacteria in endothelial cells, and 1 fetus with pericarditis had similar bacteria within mesothelial cells or macrophages. Immunohistochemistry for Chlamydia spp. or polymerase chain reaction (PCR) for Chlamydia pecorum or both, performed on brain or pooled tissue, were positive in all 14 tested fetuses that had meningoencephalitis and in 4/4 calves and in 3/4 tested cows that had meningoencephalitis and thrombotic vasculitis. In 1 calf and 11/11 fetuses, C. pecorum PCR amplicon sequences were 100% homologous to published C. pecorum sequences. Enzootic chlamydiosis due to C. pecorum was the identified cause of the late term abortions and the vasculitis and meningoencephalitis in fetuses, calves, and cows. C. pecorum, an uncommon bovine abortogenic agent, is a differential diagnosis in late-term aborted fetuses with meningoencephalitis, vasculitis, and polyserositis.

Sporadic bovine encephalopathy caused by Chlamydia pecorum secondary to bovine viral diarrhoea virus infection in calves in South Australia

“…All subjects in that investigation (n = 51) tested positive to C. pecorum during the period of investigation, with a peak occurring after co‐mingling began 9 . While faecal‐oral and genitourinary‐oral routes have traditionally been considered the methods of spread, 1,10 social behaviours like grooming and mutual inhalation, or environmental factors like overcrowding have also been suggested 4 . This is consistent with our case, where calves were reaching the age of being active and interactive with their fellow herd members.…”

“…This presentation is atypical for C. pecorum infection in cattle, being more consistent with syndromes seen with C. abortus infection 1 . In this study, 10 calves without clinical signs were not tested, so there is no indication of disease prevalence within the herd, or the occurrence of subclinical cases.…”

“…These insights identify the potential significance of chlamydial diseases in Australian cattle. Current knowledge of Chlamydia infection in Australian cattle is held in case reports, 5,10 industry-based documents 12 and anecdotal information from veterinary practitioners. 5 Surveillance will assist in understanding the disease's magnitude, distribution, and significance.…”

“…Previous studies have used C. pecorum-specific PCR to confirm the species causing lesions identified in Chlamydia infections and suggest its use could be very helpful in a surveillance operation for C. pecorum. 5,10 Nonetheless, PCR can have limited success due to intermittent shedding of Chlamydia spp. during the disease state and an appropriate tissue must be sampled during a shedding phase to achieve a positive diagnosis.…”

Chlamydia pecorum detection in aborted and stillborn lambs from Western Australia

“…The high loads of C. pecorum detected in placenta and foetal liver from aborted and stillborn lambs (Table 2 ) was consistent with observations for other clinical diseases associated with C. pecorum [ 44 , 55 , 56 ]. Finally, MLST and ompA characterisation of high load C. pecorum DNA from aborted and stillborn lambs identified ST23 type strains that were identical to other globally distributed ST23 strains associated with pathology in sheep and cattle, including abortion [ 18 , 60 ], arthritis [ 61 , 62 ] and conjunctivitis [ 61 , 62 ] in sheep, and sporadic bovine encephalopathy in cattle [ 44 , 61 ]. Emerging evidence of abortigenic potential of C. pecorum is perhaps not surprising given the closely related C. abortus is an important cause of abortion in sheep in other countries, and C. psittaci is a cause of abortion in horses [ 63 , 64 ].…”