Mycoplasma bovis infections in Swiss dairy cattle: a clinical investigation

Abstract

Mycoplasma bovis causes mastitis in dairy cows and is associated with pneumonia and polyarthritis in cattle. The present investigation included a retrospective case–control study to identify potential herd-level risk factors for M. bovis associated disease, and a prospective cohort study to evaluate the course of clinical disease in M. bovis infected dairy cattle herds in Switzerland. Eighteen herds with confirmed M. bovis cases were visited twice within an average interval of 75 d. One control herd with no history of clinical mycoplasmosis, matched for herd size, was randomly selected within a 10 km range for each case herd. Animal health data, production data, information on milking and feeding-management, housing and presence of potential stress- factors were collected. Composite quarter milk samples were aseptically collected from all lactating cows and 5% of all animals within each herd were sampled by nasal swabs. Organ samples of culled diseased cows were collected when logistically possible. All samples were analyzed by real-time polymerase chain reaction (PCR). In case herds, incidence risk of pneumonia, arthritis and clinical mastitis prior to the first visit and incidence rates of clinical mastitis and clinical pneumonia between the two visits was estimated. Logistic regression was used to identify potential herd-level risk factors for M. bovis infection. In case herds, incidence risk of M. bovis mastitis prior to the first visit ranged from 2 to 15%, whereas 2 to 35% of the cows suffered from clinical pneumonia within the 12 months prior to the first herd visit. The incidence rates of mycoplasmal mastitis and clinical pneumonia between the two herd visits were low in case herds (0–0.1 per animal year at risk and 0.1-0.6 per animal year at risk, respectively). In the retrospective-case-control study high mean milk production, appropriate stimulation until milk-let-down, fore-stripping, animal movements (cattle shows and trade), presence of stress-factors, and use of a specific brand of milking equipment, were identified as potential herd-level risk factors. The prospective cohort study revealed a decreased incidence of clinical disease within three months and prolonged colonization of the nasal cavity by M. bovis in young stock.

Identification of subclinical mastitis caused by Mycoplasma spp. from screenings of bulk tanks

“…Previous studies using molecular techniques for diagnosis have shown low prevalence of bovine mastitis caused by Mycoplasma spp., such as 2.08% found in this study, 8.2% in Greece (Filioussis et al, 2007), and 2.4% in Switzerland (Aebi et al, 2015). Research conducted in Brazil also showed similar results when either herds or mammary quarters were evaluated.…”

Gap analysis ofMycoplasma bovisdisease, diagnosis and control: An aid to identify future development requirements

“…Although there is a common theme that isolates can be assigned to one of only a few population clusters (or clonal complexes in the case of MLST studies), each cluster may contain more than a dozen‐related profiles (or sequence types for MLST data), depending upon the sample size, population under investigation and discriminatory power of the technique used. Recent studies exploiting these techniques have revealed the emergence of a dominant‐type associated with mastitis in Israel (Lysnyansky et al., ), the appearance of a lineage associated with severe mastitis in Switzerland and Austria (Aebi et al., , ; Bürki, Spergser, Bodmer, & Pilo, ; Spergser et al., ) and the predominance of a single cluster, which is linked to the selection of antimicrobial‐resistant strains, in France (Becker, Thibault, Arcangioli, & Tardy, ). In another MLST study, no association was disclosed between sequence type and anatomical origin, although certain STs were only found in bison isolates (Register et al., ).…”

“…M. bovis is the most frequently occurring mycoplasma pathogen linked to pneumonia, mastitis and arthritis in cattle. While M. bovis is primarily thought of as a pneumonic disease problem in calves (Castillo‐Alcala et al., ; Timsit, Arcangioli, Bareille, Seegers, & Assié, ), and mastitis in dairy cattle (Aebi, Bodmer, Frey, & Pilo, ; Aebi et al., ), little is known about bovine respiratory disease (BRD) in bulls and cows over 1 year old, which has been observed as a significant problem in northern Italy (Radaelli, Luini, Loria, Nicholas, & Scanziani, ). Whether this situation is restricted to this single geographical area or is a more pervasive problem worldwide has not been reported in the currently available literature.…”

The status of Mycoplasma bovis infection in clinical mastitis cases in China

“…However, because as many as 25% of clinical and 40% of subclinical mastitis cases were not detected, cases of mastitis caused by M. bovis were completely undiagnosed in Europe and Israel (Bradley et al 2007;Lysnyansky et al 2016). To date, outbreaks of mastitis attributed to M. bovis have been reported in Denmark (Nielsen et al 2015), Northern Greece (Filioussis et al 2007), the Netherlands (Heuvelink et al 2016), Australia (Schibrowski et al 2018, Switzerland (Aebi et al 2015), Belgium, and Germany and Italy (Barberio et al 2016). Investigations of the pathogen in clinical cases of mastitis in China are also limited.…”