Streptococcus agalactiae , S. dysgalactiae and S. uberis are Gram-positive bacterial pathogens that affect cows in dairy herds. These are considered as the major causes of economic losses of dairy producers without a control program. To reveal the role of these agents in inducing subclinical mastitis in dairy cattle in Ahvaz, 100 CMT-positive milk samples and 20 CMT-negative milk samples were c...

UNLABELLED Quorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species c...

Human streptococci that belong to Streptococcus dysgalactiae subspecies equisimilis (SDSE) have long been known under the name of beta-hemolytic groups C and G streptococci. Extensive taxonomic studies during the past years have distinguished most of the veterinary pathogens belonging to Lancefield groups C and G from those of human origin. After being considered nonpathogenic for many years, S...

We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010-March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and ...

PURPOSE Erythromycin-resistant beta-hemolytic streptococci (BHS) has recently emerged and quickly spread between and within countries throughout the world. In this study, we evaluate the antimicrobial susceptibility patterns and erythromycin resistance mechanisms of BHS during 2003-2004. MATERIALS AND METHODS The MICs of seven antimicrobials were determined for 204 clinical isolates of BHS fr...