The cyl genes of Streptococcus agalactiae are involved in the production of pigment

Spellerberg, Barbara

doi:10.1016/s0378-1097(00)00224-x

Cited by 27 publications

(36 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These data confirmed that the increased hemolytic zone around csrR mutant colonies reflected a marked increase in beta-hemolysin production. Previous studies have noted an association between beta-hemolytic activity of GBS strains and production of orange pigment, and the cyl gene cluster appears to be required for both (24,30). Consistent with those findings, we observed an obvious increase in orange pigment in cultures of 515csrR⌬ and 2603csrR⌬ relative to the wild-type strains (not shown).…”

Section: Identification Of Csrrs Orthologs In the Gbs Genomesupporting

confidence: 92%

Regulation of Virulence by a Two-Component System in Group B Streptococcus

et al. 2005

View full text Add to dashboard Cite

Group B Streptococcus (GBS) is frequently carried in the gastrointestinal or genitourinary tract as a commensal organism, yet it has the potential to cause life-threatening infection in newborn infants, pregnant women, and individuals with chronic illness. Regulation of virulence factor expression may affect whether GBS behaves as an asymptomatic colonizer or an invasive pathogen, but little is known about how such factors are controlled in GBS. We now report the characterization of a GBS locus that encodes a two-component regulatory system similar to CsrRS (or CovRS) in Streptococcus pyogenes. Inactivation of csrR, encoding the putative response regulator, in two unrelated wild-type strains of GBS resulted in a marked increase in production of beta-hemolysin/cytolysin and a striking decrease in production of CAMP factor, an unrelated cytolytic toxin. Quantitative RNA hybridization experiments revealed that these two phenotypes were associated with a marked increase and decrease in expression of the corresponding genes, cylE and cfb, respectively. The CsrR mutant strains also displayed increased expression of scpB encoding C5a peptidase. Similar, but less marked, changes in gene expression were observed in CsrS (putative sensor component) mutants, evidence that CsrR and CsrS constitute a functional two-component system. Experimental infection studies in mice demonstrated reduced virulence of both CsrR and CsrS mutant strains relative to the wild type. Together, these results indicate that CsrRS regulates expression of multiple GBS virulence determinants and is likely to play an important role in GBS pathogenesis. Group B Streptococcus (GBS) (or Streptococcus agalactiae)is an important cause of invasive infection in newborn infants, in women around the time of childbirth, and in older individuals with underlying chronic illnesses (28). Although GBS has the capacity to produce life-threatening infection in susceptible hosts, more often it behaves as a harmless commensal organism. Surveys of asymptomatic volunteers have demonstrated that GBS colonizes the vagina and/or rectum of one-third to one-half of healthy women (12). Because GBS encounters a variety of environmental conditions in the varied niches it occupies, the organism's survival in the human host may be enhanced by its ability to perceive changes in the external milieu and to adapt by altering expression of specific genes. This dynamic adaptation of GBS to the human host is likely to involve one or more regulatory systems that control expression of bacterial factors important in adhesion, nutrient acquisition, resistance to host immune effectors, and under certain circumstances, invasion of host tissues.One mechanism for adaptation to changing environments is through two-component regulatory systems, a family of proteins that are widely distributed among many bacterial genera (20,32). Two-component systems allow sensing of specific environmental signals through a sensor histidine kinase that is usually associated with the cell membrane. In the basic mode...

show abstract

Section: Identification Of Csrrs Orthologs In the Gbs Genomesupporting

confidence: 92%

Regulation of Virulence by a Two-Component System in Group B Streptococcus

et al. 2005

View full text Add to dashboard Cite

show abstract

“…In the present study, 48.1% isolates had the cyl gene. Spellerberg et al (2000) observed that 23% isolates were positive for the cyl, while Bergseng et al (2007) found 34.3% positivity. The hylB gene codes group B Streptococcal hyaluronate lyase which cleaves hyaluronic acid, a component of extracellular matrix, to N-acetylglucosamine and glucuronic acid.…”

Section: Discussionmentioning

confidence: 97%

Antimicrobial resistance and virulence-related genes ofStreptococcusobtained from dairy cows with mastitis in Inner Mongolia, China

Ding

Zhao

et al. 2015

Pharmaceutical Biology

View full text Add to dashboard Cite

Context: Mastitis is the most expensive disease in the dairy cattle industry and results in decreased reproductive performance. Streptococcus, especially Streptococcus agalactiae, possesses a variety of virulence factors that contribute to pathogenicity. Objective: Streptococcus isolated from mastitis was tested to assess the prevalence of antimicrobial resistance and distribution of antibiotic resistance-and virulence-related genes. Materials and methods: Eighty-one Streptococcus isolates were phenotypically characterized for antimicrobial resistance against 15 antibiotics by determining minimum inhibitory concentrations (MIC) using a micro-dilution method. Resistance-and virulence-related genes were detected by PCR. Results: High percentage of resistance to b-lactams, along with tetracycline and erythromycin, was found. Resistance to three or more of seven antimicrobial agents was observed at 88.9%, with penicillin-tetracycline-erythromycin-clindamycin as the major profile in Streptococcus isolates. Resistant genes were detected by PCR, the result showed that 86.4, 86.4, 81.5, and 38.3% of isolates were mainly carrying the pbp2b, tetL, tetM, and ermB genes, respectively. Nine virulence genes were investigated. Genes cyl, glnA, cfb, hylB, and scaA were found to be in 50% of isolates, while 3.7, 21, and 4.9% of isolates were positive for bca, lmb, and scpB, genes, respectively. None of the isolates carried the bac gene. Discussion and conclusion: This study suggests the need for prudent use of antimicrobial agents in veterinary clinical medicine to avoid the increase and dissemination of antimicrobial resistance arising from the use of antimicrobial drugs in animals.

show abstract

“…Using ISS1 transposon mutagenesis, Spellerberg et al identified a cluster of genes that are required for the hemolytic activity of S. agalactiae (16). This cluster comprises at least 12 open reading frames that appear to belong to a single operon called cyl (15). It comprises genes encoding an ABC transporter (cylA, cylB), an acyl carrier protein homologue (acpC), additional proteins involved in fatty acid biosynthesis (cylD, cylG, cylZ, and cylI), a putative aminomethyltransferase (cylF), and a putative glycosyltransferase (cylJ); it also comprises three GBSspecific genes (cylX, cylE, and cylK) of unknown function.…”

mentioning

confidence: 99%

The Putative Glycosyltransferase-Encoding Gene cylJ and the Group B Streptococcus (GBS)-Specific Gene cylK Modulate Hemolysin Production and Virulence of GBS

et al. 2007

View full text Add to dashboard Cite

Group B streptococcus (GBS) expresses a hemolysin/cytolysin that plays an important role in pathogenesis. Using the Himar1 transposon mutagenesis system, a hypohemolytic mutant carrying an interrupted cylJ gene was characterized. cylJ, encoding a putative glycosyltransferase, and cylK, whose product is unknown, are both required for the full hemolytic/cytolytic activity, pigment formation, and virulence of GBS.Streptococcus agalactiae (also known as group B streptococcus [GBS]) is a commensal organism found in the gastrointestinal and genitourinary tracts of healthy individuals. However, in certain circumstances, mostly in neonates, GBS can become a life-threatening pathogen, causing invasive infections such as pneumonia, sepsis, and meningitis. The hemolysin/cytolysin expressed by GBS is an important virulence factor (8). Using ISS1 transposon mutagenesis, Spellerberg et al. identified a cluster of genes that are required for the hemolytic activity of S. agalactiae (16). This cluster comprises at least 12 open reading frames that appear to belong to a single operon called cyl (15). It comprises genes encoding an ABC transporter (cylA, cylB), an acyl carrier protein homologue (acpC), additional proteins involved in fatty acid biosynthesis (cylD, cylG, cylZ, and cylI), a putative aminomethyltransferase (cylF), and a putative glycosyltransferase (cylJ); it also comprises three GBSspecific genes (cylX, cylE, and cylK) of unknown function. The ABC transporter encoded by this operon (cylA and cylB)

show abstract

The cyl genes of Streptococcus agalactiae are involved in the production of pigment

Cited by 27 publications

References 13 publications

Regulation of Virulence by a Two-Component System in Group B Streptococcus

Regulation of Virulence by a Two-Component System in Group B Streptococcus

Antimicrobial resistance and virulence-related genes ofStreptococcusobtained from dairy cows with mastitis in Inner Mongolia, China

The Putative Glycosyltransferase-Encoding Gene cylJ and the Group B Streptococcus (GBS)-Specific Gene cylK Modulate Hemolysin Production and Virulence of GBS

Contact Info

Product

Resources

About