scholarly journals Genetic characterization and diversity of Streptococcus agalactiae isolates with macrolide resistance

2010 ◽  
Vol 59 (7) ◽  
pp. 780-786 ◽  
Author(s):  
Monika Brzychczy-Włoch ◽  
Tomasz Gosiewski ◽  
Małgorzata Bodaszewska ◽  
Wojciech Pabian ◽  
Małgorzata Bulanda ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Macrolide Resistance ◽  
Surface Proteins ◽  
Erythromycin Resistance ◽  
High Genetic Diversity ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Group B

Macrolide resistance in 169 Streptococcus agalactiae [group B streptococcus (GBS)] isolates originating from pregnant carriers was investigated. Using multiplex PCR the presence of genes encoding erythromycin resistance and capsular polysaccharides, as well as surface proteins, was determined. Random amplification of polymorphic DNA (RAPD) and PFGE were used to characterize specific clones among the isolates. In the examined population of women, erythromycin-resistant strains were found in 4.5 % of patients, whereas clindamycin-resistant strains were found in 3 % of patients, which was 16 % of strains resistant to erythromycin and 10 % of strains resistant to clindamycin among GBS isolates, respectively. Among the isolates, the largest percentage was represented by the constitutive macrolide–lincosamide–streptogramin B (cMLSB) phenotype (63 %), then the inductive macrolide–lincosamide–streptogramin B (iMLSB) phenotype (26 %) and the macrolide resistance (M) phenotype (11 %). The ermB gene was indicated in all isolates with the cMLSB phenotype and V serotype, whereas mefA/mefE genes were found in isolates with the M phenotype and Ia serotype. Among resistance isolates, serotype V was predominant (67 %), followed by serotypes II (15 %), Ia (11 %) and III (7 %). The most common surface protein encoding genes were alp3 (70 %), then rib (11 %), epsilon (7.5 %), bca (7.5 %) and alp2 (4 %). A statistically significant relationship between macrolide resistance, serotype V and the alp3 gene was demonstrated. PFGE, in comparison to the RAPD method, gave better genetic discrimination of GBS isolates. A relatively high genetic diversity among investigated strains was shown. In addition, the largest genetic homogeneity was found in serotype V.

scholarly journals Prevalence and Mechanisms of Macrolide Resistance in Invasive and Noninvasive Group B Streptococcus Isolates from Ontario, Canada

2001 ◽  
Vol 45 (12) ◽  
pp. 3504-3508 ◽  
Author(s):  
Joyce C. S. de Azavedo ◽  
Mary McGavin ◽  
Carla Duncan ◽  
Donald E. Low ◽  
Allison McGeer
Keyword(s):  
Group B Streptococcus ◽  
Tetracycline Resistance ◽  
Macrolide Resistance ◽  
Limited Information ◽  
Erythromycin Resistance ◽  
Vaginal Swabs ◽  
Resistant Strains ◽  
Neonatal Blood ◽  
Methylase Gene ◽  
Group B

ABSTRACT Macrolide resistance has been demonstrated in group B streptococcus (GBS), but there is limited information regarding mechanisms of resistance and their prevalence. We determined these in GBS obtained from neonatal blood cultures and vaginal swabs from pregnant women. Of 178 isolates from cases of neonatal GBS sepsis collected from 1995 to 1998, 8 and 4.5% were resistant to erythromycin and clindamycin, respectively, and one isolate showed intermediate penicillin resistance (MIC, 0.25 μg/ml). Of 101 consecutive vaginal or rectal/vaginal isolates collected in 1999, 18 and 8% were resistant to erythromycin and clindamycin, respectively. Tetracycline resistance was high (>80%) among both groups of isolates. Of 32 erythromycin-resistant isolates, 28 possessed the ermmethylase gene (7 ermB and 21 ermTR/ermA) and 4 harbored the mefA gene; one isolate harbored both genes. One isolate which was susceptible to erythromycin but resistant to clindamycin (MIC, 4 μg/ml) was found to have thelinB gene, previously identified only inEnterococcus faecium. The mreA gene was found in all the erythromycin-resistant strains as well as in 10 erythromycin-susceptible strains. The rate of erythromycin resistance increased from 5% in 1995–96 to 13% in 1998–99, which coincided with an increase in macrolide usage during that time.

scholarly journals Reverse Line Blot Assay for Direct Identification of Seven Streptococcus agalactiae Major Surface Protein Antigen Genes

2006 ◽  
Vol 13 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Zuotao Zhao ◽  
Fanrong Kong ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Streptococcus Agalactiae ◽  
Blot Hybridization ◽  
Group B Streptococcus ◽  
Immunoglobulin A ◽  
Surface Protein ◽  
Epidemiological Studies ◽  
Reverse Line Blot ◽  
Variable Surface ◽  
Group B ◽  
Major Surface

ABSTRACT We developed a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB) to detect the genes encoding members of the family of variable surface-localized proteins of Streptococcus agalactiae (group B streptococcus [GBS]), namely, Bca (Cα), Rib, Epsilon (Epsilon/Alp1/Alp5), Alp2, Alp3, and Alp4, and the immunoglobulin A binding protein, Bac (Cβ). We used the assay to identify these genes in a collection of well-characterized GBS isolates and reference strains. The results showed that mPCR/RLB avoids the common problems of cross-reaction and nontypability associated with protein typing using antisera. It is as sensitive as, but more practical than, separate gene-specific PCRs and would be suitable for large molecular epidemiological studies of GBS.

scholarly journals Erythromycin and Clindamycin Resistance and Telithromycin Susceptibility in Streptococcus agalactiae

2003 ◽  
Vol 47 (3) ◽  
pp. 1112-1114 ◽  
Author(s):  
C. Betriu ◽  
E. Culebras ◽  
M. Gómez ◽  
I. Rodríguez-Avial ◽  
B. A. Sánchez ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Macrolide Resistance ◽  
Erythromycin Resistance ◽  
Resistant Strains

ABSTRACT The rates of resistance to erythromycin and clindamycin among Streptococcus agalactiae strains isolated in our hospital increased from 4.2 and 0.8% in 1993 to 17.4 and 12.1%, respectively, in 2001. Erythromycin resistance was mainly due to the presence of an Erm(B) methylase, while the M phenotype was detected in 3.8% of the strains. Telithromycin was very active against erythromycin-resistant strains, irrespective of their mechanisms of macrolide resistance.

scholarly journals Towards a genotyping system for Streptococcus agalactiae (group B streptococcus): use of mobile genetic elements in Australasian invasive isolates

2003 ◽  
Vol 52 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Fanrong Kong ◽  
Diana Martin ◽  
Gregory James ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Streptococcus Agalactiae ◽  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Mobile Genetic Elements ◽  
Genetic Elements ◽  
Gene Profiles ◽  
Polysaccharide Synthesis ◽  
Genetic Clusters ◽  
Group B

This study forms part of the development of an integrated genotyping system for Streptococcus agalactiae (group B streptococcus, GBS) that can be used to study the population genetics of the organism and the pathogenesis and epidemiology of GBS disease. In recent previous studies, two sets of markers, the capsular polysaccharide synthesis (cps) gene cluster and surface protein antigen genes, have been used to assign molecular serotypes (MS) and protein-gene profiles (PGP) to more than 200 isolates. In the present study, five mobile genetic elements (MGE) have been used as a third set of markers, to characterize further 194 invasive isolates, recovered from blood or cerebrospinal fluid (CSF). Of these, 97 % contained one or more of the five MGE, the distribution of which was related to MS and PGP, as illustrated by MS III, which is divisible into four serosubtypes with different combinations of the MGE (or none). Fifty-six different genotypes and eight genetic clusters were identified, each with different combinations of the three sets of molecular markers. Five predominant genotypes (Ia-1, Ib-1, III-1, III-2 and V-1) contained 62 % of the isolates and five of the eight genetic clusters contained 92 % of the isolates. The 17 CSF isolates were relatively widely distributed between 10 genotypes and across seven of the eight clusters. Further study is needed to determine whether these genotypes or clusters share common markers of increased virulence. In future, comparison of invasive with colonizing strains of GBS may elucidate the significance of these findings.

scholarly journals Identification of Major Outer Surface Proteins of Streptococcus agalactiae

2002 ◽  
Vol 70 (3) ◽  
pp. 1254-1259 ◽  
Author(s):  
Martin J. G. Hughes ◽  
Joanne C. Moore ◽  
Jonathan D. Lane ◽  
Rebecca Wilson ◽  
Philippa K. Pribul ◽  
...  
Keyword(s):  
Outer Surface ◽  
Streptococcus Agalactiae ◽  
Expression System ◽  
Group B Streptococcus ◽  
Phosphoglycerate Kinase ◽  
Peptide Sequencing ◽  
Surface Proteins ◽  
Outer Surface Proteins ◽  
Group B

ABSTRACT To identify the major outer surface proteins of Streptococcus agalactiae (group B streptococcus), a proteomic analysis was undertaken. An extract of the outer surface proteins was separated by two-dimensional electrophoresis. The visualized spots were identified through a combination of peptide sequencing and reverse genetic methodologies. Of the 30 major spots identified as S. agalactiae specific, 27 have been identified. Six of these proteins, previously unidentified in S. agalactiae, were sequenced and cloned. These were ornithine carbamoyltransferase, phosphoglycerate kinase, nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, purine nucleoside phosphorylase, enolase, and glucose-6-phosphate isomerase. Using a gram-positive expression system, we have overexpressed two of these proteins in an in vitro system. These recombinant, purified proteins were used to raise antisera. The identification of these proteins as residing on the outer surface was confirmed by the ability of the antisera to react against whole, live bacteria. Further, in a neonatal-animal model system, we demonstrate that some of these sera are protective against lethal doses of bacteria. These studies demonstrate the successful application of proteomics as a technique for identifying vaccine candidates.

scholarly journals In VitroActivity of Solithromycin against Erythromycin-Resistant Streptococcus agalactiae

2013 ◽  
Vol 58 (3) ◽  
pp. 1693-1698 ◽  
Author(s):  
Giorgio Piccinelli ◽  
Prabhavathi Fernandes ◽  
Carlo Bonfanti ◽  
Francesca Caccuri ◽  
Arnaldo Caruso ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Phenotypic Characterization ◽  
Content Type ◽  
Resistant Strains ◽  
Group B ◽  
Microdilution Broth

ABSTRACTThein vitroantibacterial activity of solithromycin (CEM-101) against macrolide-resistant isolates (n= 62) ofStreptococcus agalactiae(group B streptococcus [GBS]) was determined. Phenotypic characterization of macrolide-resistant strains was performed by double-disc diffusion testing. A multiplex PCR was used to identify theerm(B),erm(TR), andmef(A/E) genes, capsular genotypes, and alpha-like (Alp) protein genes from the GBS strains. Determination of MIC was carried out using the microdilution broth method. The Etest method was used for penicillin, azithromycin, clarithromycin, and erythromycin. Solithromycin had a MIC50of ≤0.008 μg/ml and a MIC90of 0.015 μg/ml against macrolide-susceptibleS. agalactiae. These MICs were lower than those displayed by penicillin (MIC50of 0.032 μg/ml and MIC90of 0.047 μg/ml), the antibiotic agent of choice for prophylaxis and treatment of GBS infections. Against macrolide-resistantS. agalactiae, solithromycin had a MIC50of 0.03 μg/ml and a MIC90of 0.125 μg/ml. Againsterm(B) strains, solithromycin had a MIC50of 0.03 μg/ml and a MIC90of 0.06 μg/ml, while againstmef(A) strains, it had a MIC50of 0.03 μg/ml and a MIC90of 0.125 μg/ml. Most erythromycin-resistant GBS strains were of serotype V (64.5%) and associated significantly withalp2-3. Moreover, a statistically significant association was observed between the constitutive macrolide-lincosamide-streptogramin B resistance (cMLSB) phenotype and theerm(B) gene-carrying strains, thealp2-3gene and the M phenotype, and themef(A/E) gene andepsilon. Overall, our results show that solithromycin had lower or similar MICs than penicillin and potent activity against macrolide-resistant strains independent of their genotype or phenotype, representing a valid therapeutic alternative where β-lactams cannot be used.

Serotype and surface protein gene distribution of colonizing group B streptococcus in women in Egypt

2013 ◽  
Vol 142 (1) ◽  
pp. 208-210 ◽  
Author(s):  
S. SHABAYEK ◽  
S. ABDALLA ◽  
A. MH. ABOUZEID
Keyword(s):  
High Frequency ◽  
Protein Gene ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Surface Proteins ◽  
Protein Encoding ◽  
Vaginal Swabs ◽  
Surface Protein Gene ◽  
Group B ◽  
Encoding Genes

SUMMARYGroup B streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis. We determined the distribution of serotypes and surface protein encoding genes of GBS strains from pregnant and non-pregnant women in Egypt. Vaginal swabs from 364 women were screened by culture and 100 (27·4%) yielded GBS. Serotype V was the most predominant (33%), followed by serotypes II (17%), III (15%), Ia (14%), VI (12%), Ib (8%) and IV (1%). The most common surface protein genes were epsilon (27%), alp3 (26%), bca (18%), rib (16%) and alp2 (10%). Two isolates were negative for surface protein genes. The distribution of serotypes and surface proteins was similar to reports from other parts of the world but the relatively high frequency of serotype VI was a notable feature of the strains from women in Egypt.

scholarly journals Infection and drug resistance of Streptococcus agalactiae among perinatal pregnant women in Xinjiang

2021 ◽  
Author(s):  
Shuli Guo ◽  
Xiandao Luo ◽  
Haiying Jia ◽  
Xiuhui Pang ◽  
Changmin Wang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Target Site ◽  
Macrolide Resistance ◽  
Diffusion Method ◽  
Resistance Phenotype ◽  
Ermb Gene ◽  
Group B

Abstract Background: Group B streptococcus (Streptococcus agalactiae) is one of the most common pathogens causing meningitis, bacteremia and pneumonia. The drug resistance mechanisms of group B streptococcus in different countries and regions also show regional differences.Method: The study population was comprised of 1877 pregnant women of 34-38 weeks who underwent prenatal examination in the gynecology and obstetrics outpatient clinic of Xinjiang People's Hospital, between January 1, 2019 and January 31, 2020. Clinic specimens were collected and identified by the API bacteria Rapid Identification card for the downstream group B Streptococcus (Streptococcus agalactiae) isolation. Drug susceptibility of the Streptococcus agalactiae isolated was detected by Kirby-Bauer disk diffusion method. Macrolide–lincosamide–streptogramin B (MLSB) resistance was determined by D test. Real-time quantitative polymerase chain reaction and Gene sequencing was performed for the resistance genes ermA, ermB, mreA, erm (47), mefA/E and Lin B.Results: 149 Streptococcus agalactiae-positive strains were identified by clinical isolation, with a positive rate of 7.94%. Group B Streptococcus showed 100% susceptibility to linezolid, penicillin, vancomycin, meropenem, ampicillin, ceftriaxone, 44.97%, 35.57%, 56.38% and 29.53% susceptibility to levofloxacin, erythromycin, tetracycline and clindamycin, respectively. Among the 149 isolates, 127 strains showed macrolide resistance phenotype. The detection rate of intrinsic resistance phenotype (cMLS) was 40.94% (59/127), active efflux resistance phenotype (MS) 9.45% (12/127), and induced resistance phenotype (iMLS) 22.83% (29/127).Conclusion: The ermB gene-mediated 50s ribosome target site change co-existing with mreA gene for macrolide resistance efflux may play a major role in the mechanism of Streptococcus agalactiae resistance macrolide resistance of in perinatal women in Xinjiang. The change of 50s ribosomal target site mediated by ermB gene may be the main reason for drug cross-resistance.

Analysis of phenotype, genotype and serotype distribution in erythromycin-resistant group B streptococci isolated from vaginal flora in Southern Ireland

2009 ◽  
Vol 138 (2) ◽  
pp. 286-291 ◽  
Author(s):  
R. A. KIELY ◽  
B. LUCEY ◽  
L. COTTER
Keyword(s):  
Group B Streptococcus ◽  
Latex Agglutination ◽  
Macrolide Resistance ◽  
Pcr Analysis ◽  
Erythromycin Resistance ◽  
Childbearing Age ◽  
Group B Streptococci ◽  
Pcr Products ◽  
Resistant Group ◽  
Group B

SUMMARYThe screening of 2000 women of childbearing age in Cork between 2004 and 2006 produced 37 erythromycin-resistant group B streptococcus (GBS) isolates. PCR analysis was performed to determine the basis for erythromycin resistance. The ermTR gene was most frequently expressed (n=19), followed by the ermB gene (n=8). Four isolates harboured the mefA gene. Six isolates yielded no PCR products. Some phenotype–genotype correlation was observed. All isolates expressing the mefA gene displayed the M phenotype whilst all those expressing ermB displayed the constitutive macrolide resistance (cMLSB) phenotype. Of 19 isolates that expressed the ermTR gene, 16 displayed the inducible macrolide resistance (iMLSB) phenotype. Serotype analysis revealed that serotypes III and V predominated in these isolates. The identification of two erythromycin-resistant serotype VIII isolates among this collection represents the first reported finding of erythromycin resistance in this serotype. A single isolate was non-typable using two latex agglutination serotyping kits.

Associations between capsular serotype, multilocus sequence type, and macrolide resistance inStreptococcus agalactiaeisolates from Japanese infants with invasive infections

2013 ◽  
Vol 142 (4) ◽  
pp. 812-819 ◽  
Author(s):  
M. MOROZUMI ◽  
T. WAJIMA ◽  
Y. KUWATA ◽  
N. CHIBA ◽  
K. SUNAOSHI ◽  
...  
Keyword(s):  
Clonal Complex ◽  
Vaccine Development ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Sequence Type ◽  
Macrolide Resistance ◽  
Invasive Infections ◽  
Resistant Strains ◽  
Group B ◽  
Sequence Types

SUMMARYStreptococcus agalactiae(group B streptococcus; GBS) isolates (n = 150) from infants with invasive infections between 2006 and 2011 were analysed for capsular serotype, multilocus sequence type, and antibiotic susceptibility. In cases with late-onset disease (n = 115), primary meningitis was predominant (62·6%), but represented only 39·1% in cases with early-onset disease (n = 23). The most common serotype was III (58·7%), followed by Ia (21·3%) and Ib (12·7%). Sequence types (STs) of serotype III strains included ST17 (50·0%), ST19 (26·1%), ST335 (18·2%), ST27 (4·5%), and ST1 (1·1%). Predominant STs of serotypes Ia and Ib were ST23 (81·3%) and ST10 (84·2%), respectively. No penicillin-resistant strains were detected, but 22·0% of strains hadmef(A/E),erm(A), orerm(B) genes, which mediate macrolide resistance. A new ST335, possessing anmef(A/E) gene belonging to clonal complex 19 gradually increased in frequency. Improved prevention of invasive GBS infections in infants requires timely identification, and ultimately vaccine development.

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