Transport of 2-deoxyglucose or glucose in Streptococcus agalactiae was strongly inhibited if the cells were first exposed to a combination of lactoperoxidase-thiocyanate-hydrogen peroxide (LP-complex). The inhibition was completely reversible with dithiothreitol. N-ethylmaleimide and p-chloromercuribenzoate inhibited sugar transport, and the inhibition was also reversible with dithiothreitol. S...

The purpose of this study was to develop a loop-mediated isothermal amplification (LAMP) method for rapid, sensitive, and simple detection of Streptococcus agalactiae in farmed fish. A set of four primers, two outer and two inner, was designed from the fibrinogen-binding (fbsB) proteins gene sequence of S. agalactiae, and conditions for LAMP were optimized as incubation of all reagents for 60 m...

The sip gene encoding for a conserved highly immunogenic surface protein of Streptococcus agalactiae was amplified using polymerase chain reaction (PCR) and subcloned into prokaryotic expression vector pET32a (+) and expressed as a recombinant protein in E. coli BL21 (DE3). An indirect enzyme linked immunosorbent assay (ELISA) was developed using the purified Sip protein as a coating antigen, w...

Streptococcus agalactiae (Lancefield group B; group B streptococci) is a major pathogen that causes meningoencephalitis in fish, mastitis in cows, and neonatal sepsis and meningitis in humans. The available prophylactic measures for conserving human and animal health are not totally effective and have limitations. Effective vaccines against the different serotypes or genotypes of pathogenic str...

This study investigated the in vitro activity of gemifloxacin (SB-265805) against 50 recent clinical isolates of Streptococcus pyogenes, Streptococcus agalactiae and viridans streptococci using the microdilution method. This activity was compared with that of the quinolone agents ofloxacin, ciprofloxacin, levofloxacin, trovafloxacin and grepafloxacin, and with that of penicillin, ampicillin, cl...

Cystine reduction in Streptococcus agalactiae, resulting in sulfhydryl formation, may account for antagonism of the antibacterial effect of lactoperoxidase-thiocyanate-hydrogen peroxide when cystine is present in excess of the amount needed for maximum growth. Accumulation of cystine by S. agalactiae and its reduction to form sulfhydryl compounds were demonstrated. The reduction of cystine appe...

Mastitis, a severe infectious disease among dairy cattle, is still a challenge for livestock treatment due to the increased infections by antibiotic resistant strains. Antimicrobial peptides could be the alternate for treating such drug resistant strains. In the present study, the whey proteins extracted from buffalo milk was subjected to enzymatic hydrolysis using trypsin, chymotrypsin, pepsin...

Streptococcus agalactiae UCN70, isolated from a vaginal swab obtained in New Zealand, is resistant to lincosamides and streptogramins A (LS(A) phenotype) and also to tiamulin (a pleuromutilin). By whole-genome sequencing, we identified a 5,224-bp chromosomal extra-element that comprised a 1,479-bp open reading frame coding for an ABC protein (492 amino acids) 45% identical to Lsa(A), a protein ...

Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding fo...

The use of PCR tests as diagnostics for intramammary infections (IMI) based on composite milk samples collected in a non-sterile manner at milk recordings is increasing. Carryover of sample material between cows and non-aseptic PCR sampling may be incriminated for misclassification of IMI with Streptococcus agalactiae (S. agalactiae) in dairy herds with conventional milking parlours. Misclassif...