Short communication: Role of Mycoplasma arginini in mastitis caused by Streptococcus dysgalactiae

Abstract

We performed a comparative study on the development of mastitis induced by Mycoplasma arginini or Streptococcus dysgalactiae after challenging the cows. Mycoplasma arginini did not cause any clinical symptoms on its own, resulting in only a transient increase of somatic cell count (SCC; increase ranging from 0.5 × 10(6) to 0.8 × 10(6) cells/mL) and a slight decrease of milk production (10%) for 5 d. In contrast, Strep. dysgalactiae induced more severe clinical signs in animals and SCC increased to 1.60 × 10(6) to 2.11 × 10(6) cells/mL for 10 d. In addition, milk production decreased (22.9 to 27.0%) for 10 d. After 3 mo (2 mo after the first challenge), animals that were challenged previously with M. arginini were rechallenged with Strep. dysgalactiae. Severe clinical mastitis developed, with very high SCC (5.00 × 10(6) to 21.5 × 10(6) cells/mL), and a very significant reduction of milk production (28.6 to 68.7%), which lasted more than 4 wk, was observed. The severe clinical mastitis developed not only in cows inoculated with Strep. dysgalactiae andM. arginini in the same udder quarter but also in cows infected in the quarter previously not challenged with mycoplasma. Cows challenged first with Strep. dysgalactiae and rechallenged with M. arginini 2 mo later developed only slight changes in both SCC and milk production, similar to those when the cows were challenged with M. arginini alone. We conclude that M. arginini infection does not cause remarkable mastitis (characterized by decrease in milk production and increase of SCC) but it significantly predisposes animals to infection with Strep. dysgalactiae, leading to severe clinical mastitis.

Evaluation of effects of Mycoplasma mastitis on milk composition in dairy cattle from South Australia

“…M. arginini has been reported elsewhere with no significant impact on milk composition, but can be considered a predisposing agent to Str. dysagalactiae leading to severe mammary gland inflammation [ 58 ]. It is important to consider that M. arginini is associated with some diseases in human [ 56 , 64 ].…”

Complete Genome Sequence of Mycoplasma arginini Strain HAZ 145_1 from Bovine Mastitic Milk in Japan

“…( 1 , 2 ). M. arginini may become a precipitating factor for bovine mastitis by other bacteria, but its pathogenicity against cows is unspecific ( 3 ). Although a draft genome sequence of M. arginini has already been reported ( 4 ), the complete genome sequence has not.…”

Risk factors associated with intramammary colonization with Mollicutes in dairy cattle from Southeast Brazil

“…Although, not associated with mastitis, this species was already recovered from bulk tank milk from herds affected with mastitis of different etiologies and it is a predisposing agent to severe intramammary infection by other bacteria. Also, it can persist in milk over long periods, which is of great importance since it has been considered to have a zoonotic potential for immunocompromised individuals (STIPKOVITS et al, 2013).…”