Adherence of Mycoplasma bovis strains to bovine bronchial epithelial cells

in Microbial Pathogenesis (2003), 34(3), 141-148

Mycoplasma bovis is responsible for considerable economic losses in cattle due to pneumonia, arthritis and mastitis. As the agent was shown to be capable of adhering to neutrophils and embryonic bovine ... [more ▼]

Mycoplasma bovis is responsible for considerable economic losses in cattle due to pneumonia, arthritis and mastitis. As the agent was shown to be capable of adhering to neutrophils and embryonic bovine lung (EBL) cells and invading the respiratory epithelium it is highly desirable to improve our understanding of cytadherence processes. Although several surface proteins likely to be directly involved in this initial stage of interaction between pathogen and host cells have been identified, these findings mainly referred to type strain PG45 adhering to the continuous EBL cell line. The present study provides new and complementary data about cytadherence of M. bovis based on adherence of various radiolabeled strains to a primary culture of bovine bronchial epithelial (BBE) cells using a standardized adherence assay. M. bovis was shown to adhere specifically to the primary culture of BBE cells. Inhibition of adherence was observed upon addition of monoclonal antibodies (MAbs), trypsin treatment of mycoplasmas, and competition with non-radiolabeled mycoplasma cells. Interestingly, three MAbs against proteins involved in adherence to EBL cells failed to inhibit significantly the adherence to BBE cells. On the other hand, significant reduction of adherence rates by MAbs 2A8 and 9F1 directed against epitopes of variable surface lipoproteins VspC and VspF, respectively, demonstrated the involvement of these proteins in adherence of M. bovis to primary culture of BBE cells. (C) 2003 Elsevier Science Ltd. All rights reserved. [less ▲]

Mycoplasma bovis dans le complexe respiratoire bovin et propriétés de cyto-adhésion in vitro

in Annales de Médecine Vétérinaire (2003), 147(4, AUG-SEP), 267-272

Mycoplasmas frequently infect cattle, causing especially respiratory diseases. Mycoplasma bovis is the most important pathogenic species in countries free of bovine contagious pleuropneumonia. This ... [more ▼]

Mycoplasmas frequently infect cattle, causing especially respiratory diseases. Mycoplasma bovis is the most important pathogenic species in countries free of bovine contagious pleuropneumonia. This species was frequently isolated in Belgium from cattle with respiratory disease. Furthermore, associations were often observed with pasteurellas and bovine respiratory syncytial virus. Of these M. bovis isolates, many were resistant to several antimicrobial agents which are used in cattle practice, except to fluoroquinolones. Inasmuch the high frequency of M. bovis isolation and antibiotic resistances, it is very important to understand the pathogenicity of this bacteria in order to optimize prophylactic tools. Therefore, the study of the cytadherence of M. bovis is essential since it represents the first step of the bacterial infection. According to our experimental results, PG45 is not representative of field isolates because of its low adherence rates to various cell lines. This could be explained by the high number of subcultures of this pathogenic strain underwent since its first isolation, which sharply contrasts with other isolates. M. bovis adheres specifically to bovine bronchial epithelial cells in primary culture. Proteins such as variable surface proteins C and F are involved in this step as observed by decreased adherence rates after trypsinization of mycoplasma cells or addition of monoclonal antibodies. [less ▲]