The presence of Mycoplasma bovis in colostrum

Abstract

In herds with Mycoplasma bovis circulation, colostrum is often considered infectious. However, in contrast to milk, the presence of M. bovis in colostrum was not previously evidenced. In this survey, the presence of M. bovis DNA was determined with real-time PCR in 368 colostrum samples from 17 herds, recently infected with M. bovis. Only 1.9% of the samples tested positive, with 13 herds having no positive samples and an overall within-herd prevalence of 3.2% (SD: 4.9%; Range: 0-30.0%). These results show that in infected herds M. bovis DNA can be retrieved in colostrum. To what extend colostrum is infectious remains to be determined.

Mycoplasma bovis Infections—Occurrence, Diagnosis and Control

“…In another qPCR for M. bovis testing [ 46 ], the nasopharyngeal swabs were cultured for 3–5 days before the analysis. The molecular methods are optimized for the detection of M. bovis in nasopharyngeal swabs and milk samples, but they can be optimized to be used for the detection of M. bovis in different specimens [ 2 , 26 , 27 , 48 , 49 ]. In 2020, a qPCR was developed for the detection of M. bovis in tracheal aspirate samples derived from calves [ 49 ].…”

“…Interesting information can be gathered by estimating on-farm/within-herd prevalence of M. bovis infections [ 26 , 27 ]. Such a repeated cross-sectional six-month study on M. bovis intramammary infections was conducted between 2017 and 2018 in four Estonian dairy herds with previously confirmed M. bovis positive status.…”

“…In the positive farms on-farm/within-herd prevalence ranged between 2.8% and 30.0%, whereas the average within-herd prevalence estimated for all seventeen herds tested was 3.2%. According to the author, the reason for such low average within-herd prevalence of M. bovis DNA obtained in this survey was probably a result of differentiation in the infection phases in the periparturient cows or false positive results of real-time PCR assays used in M. bovis DNA detection particularly due to the possibility of ongoing co-infections with other Mycoplasma species [ 27 ]. In 2009, it was reported that 1.5% of all herd tested had bulk tank milk samples positive for M. bovis confirmed by culturing and PCR [ 28 ].…”

“…Recent reports on M. bovis indicated colostrum as a possible source of infection based on positive results for M. bovis DNA [ 26 , 27 ]. Additionally, in one of these studies, herd-specific M. bovis strains were isolated from cows with clinical mastitis and calves affected with respiratory disease showing possible transmission of the pathogen between dairy cows and calves via contaminated milk.…”

“…Pasteurisation or heat treatment is one of proposals to eliminate the risk of M. bovis shedding via colostrum or raw milk. Another alternative may be to avoid pooling of colostrum within endemically infected farms, discarding colostrum originating from M. bovis affected cows, or colostrum purchasing as replacer [ 27 ]. As previously documented, a commercial on-farm pasteurizer was able to destroy Mycoplasma spp.…”