Molecular detection of Coxiella burnetii in raw meat intended for pet consumption

Abstract

The discovery of antibodies against Coxiella burnetii in cattery-confined breeding cats indicating prior or current exposure (Shapiro et al., 2015) prompted an investigation into possible sources of infection. One hypothesis was that raw meat diets containing reservoir species may provide a source of C. burnetii transmission. The aim of this pilot study was to determine whether C. burnetii DNA was present in raw meat sold exclusively for companion animal consumption. The sample population consisted of raw meat packages (n = 58) of primarily kangaroo origin, with three to four aliquots (50-120 mg) randomly selected from each package. Genomic DNA was extracted from whole tissue in each of these aliquots using a modified protocol.Three quantitative PCR assays were used for the detection of C. burnetii targeting the IS1111 gene, the heat shock operon htpAB and the C. burnetii outer membrane protein-coding gene, com1. Coxiella burnetii DNA was detected in 25/58 samples (43%) using the IS1111, htpAB and/or com1 PCR assays and confirmed by DNA sequencing.All samples amplifying a product in the com1 assay also amplified a product in the htpAB and IS1111 assays. A total of 17/58 (29%) packets were positive with all three genes, 4/58 (7%) were positive with two genes (IS1111 and htpAB) and 4/58 (7%) were positive with the IS1111 gene only. Coxiella burnetii DNA was five times more likely to be found in offal than skeletal muscle meat samples. All meat samples in which C. burnetii DNA was found were from kangaroo tissues, while samples labelled as non-kangaroo meat (n = 4) were negative. Multi-locus variable number of tandem repeat analysis (MLVA) identified three different genotypes of C. burnetii that have all been identified previously from Australian human clinical Q fever cases. Further investigations are required to determine the potential role of certain raw meats in the transmission of C. burnetii to cats and humans. K E Y W O R D Scats and dogs, Coxiella burnetii, kangaroo, pet food, Q fever, quantitative Polymerase Chain Reaction (qPCR), raw meat

Coxiella burnetii seroprevalence and Q fever in Australian wildlife rehabilitators

“…While the source of infection for the seropositive participants in this study remains unknown, the possibility that macropods can occasionally be an infection source for AWRs cannot be ruled out given the serological evidence that macropods can become infected with C. burnetii [ 10 , 52 ], and potentially shed the bacterium [ 10 , 53 , 61 ]. Further research is required to determine whether macropods are reservoirs for C. burnetii , and whether they are capable of shedding viable organism which can subsequently infect humans and cause QFD.…”

“…Infection is typically acquired via the inhalation of aerosols contaminated with the bacterium. Although domestic ruminants are the main reservoirs of human disease [ 70 ], direct evidence of C. burnetii infection has also been identified in a variety of wild and domestic animal species including: dogs [ 63 ], cats [ 42 ], horses [ 44 ] birds [ 1 ] and macropods [ 10 , 52 , 61 ]. Following human infection, clinical outcomes vary in severity, ranging from asymptomatic infection with seroconversion, to a flu-like illness.…”

“…Over the past decade in Australia, there has been an increased incidence in Q fever notifications with minimal known exposure to well-documented risk factors [ [3] , [14] , [15] , [16] , 26 , 39 , 50 , 66 ], and there is a growing body of evidence suggesting macropods, in particular kangaroos, represent a potential source of C. burnetii infection for humans. Coxiella burnetii has been isolated from the ticks of infected kangaroos [ 52 ], and C. burnetii DNA has been identified in kangaroos [ 10 , 17 , 53 , 61 ] and other wildlife including bandicoots [ 12 ] and their associated ticks [ 12 , 17 ]. A Western Australian study found C. burnetii DNA in the faeces of kangaroos co-grazing with livestock, along with a C. burnetii seroprevalence of 33% in these same animals [ 10 ].…”

“…A Western Australian study found C. burnetii DNA in the faeces of kangaroos co-grazing with livestock, along with a C. burnetii seroprevalence of 33% in these same animals [ 10 ]. Furthermore, C. burnetii DNA was recently detected in samples of raw meat containing kangaroo sold for pet consumption [ 61 ]. Ongoing occupational exposure to kangaroo and wallaby carcasses was postulated as a possible source of C. burnetii infection for a Queensland park ranger who contracted Q fever in 2015 [ 65 ].…”

Current perspectives on the occurrence of Q fever: highlighting the need for systematic surveillance for a neglected zoonotic disease in Indian subcontinent

“…The transmission between different herds occurs mostly through aerosol, trade, and transportation of animals. Moreover, transboundary animal trade and the export of foods of animal origin facilitate the infectious agent to spread across borders (Tilburg et al ., 2012; Shapiro et al ., 2020). The potential transmission pathways of C. burnetii to different hosts are given in Fig.…”