ABSTRACT
Coxiella burnetii (C. burnetii), an intracellular zoonotic bacterium causing Q fever, occurs widely in cattle herds. After invasion of the pregnant uterus and initial localization in the placenta, active C. burnetii infections may spread to the fetus hematogenously or by the amniotic-oral route and thus may cause abortion, premature delivery, stillbirth, and weak offspring (APSW) complex. In a case-control study, we investigated precolostral blood samples of 56 stillborn calves and 30 live births from a dairy herd endemically infected with C. burnetii "C-cluster" strains and an increased stillbirth rate in primiparous cows. Within the group of the stillborn calves, four precolostral blood samples (7.1%) were tested positive for C. burnetii DNA by PCR and one serum sample (1.8%) positive for anti-C. burnetii IgG antibodies by a commercial ELISA test, respectively. Neither C. burnetii DNA nor anti-C. burnetii IgG antibodies were detected in the samples of calves being born alive. In conclusion, we demonstrated that coxiellaemia and precolostral seroconversion occurred sporadically in stillborn calves from this endemically infected herd. Due to the low detection rates, C. burnetii could not be confirmed to be the cause of the increased stillbirth rate.
Subject(s)
Antibodies, Bacterial/blood , Cattle Diseases/microbiology , Coxiella burnetii/isolation & purification , DNA, Bacterial/genetics , Immunoglobulin G/blood , Q Fever/veterinary , Stillbirth/veterinary , Animals , Case-Control Studies , Cattle , Cattle Diseases/blood , Cattle Diseases/diagnosis , Cattle Diseases/embryology , Coxiella burnetii/genetics , Coxiella burnetii/immunology , Female , Male , Pregnancy , Q Fever/diagnosis , Q Fever/embryology , Q Fever/microbiologyABSTRACT
The aim of this study was to evaluate by PCR analyses the presence of Coxiella burnetii infection in fetuses of water buffalo (Bubalus bubalis) in the Campania region (Southern Italy). Samples were collected only from aborted fetuses and C. burnetii presence was evaluated by one-tube nested PCR amplification of the IS111 repetitive element. Of the 164 fetuses examined 14 (17.5%) were positive after DNA amplification, showing that C. burnetii occurs in this population of water buffaloes. However, more extensive prevalence studies need to be carried out to define the role of buffaloes as reservoirs for this pathogen and also the role of C. burnetii as an abortive agent in this animal.
