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

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.

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Telithromycin Susceptibility and Genomic Diversity of Macrolide-Resistant Serotype III Group B Streptococci Isolated in Perinatal Infections

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.2.677-680.2004 ◽

2004 ◽

Vol 48 (2) ◽

pp. 677-680 ◽

Cited By ~ 6

Author(s):

Edouard Bingen ◽

Catherine Doit ◽

Philippe Bidet ◽

Naima Brahimi ◽

Dominique Deforche

Keyword(s):

Macrolide Resistance ◽

Genomic Diversity ◽

Mechanisms Of Resistance ◽

Group B Streptococci ◽

Resistance Determinants ◽

Genetic Mechanisms ◽

Resistant Group ◽

Group B

ABSTRACT We studied the telithromycin, erythromycin, azithromycin, and clindamycin susceptibilities of serotype III macrolide-resistant group B streptococci, together with genetic mechanisms of resistance and genomic diversity. ermB, ermA, and mefA were found in, respectively, 57, 32, and 9% of isolates. The telithromycin MIC at which 90% of isolates were inhibited was 0.5 μg/ml. Macrolide resistance was associated with dissemination of resistance determinants among isolates of different genetic backgrounds.

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Evaluation of procedures for typing of group B Streptococcus: a retrospective study

PeerJ ◽

10.7717/peerj.3105 ◽

2017 ◽

Vol 5 ◽

pp. e3105 ◽

Cited By ~ 2

Author(s):

Hans-Christian Slotved ◽

Steen Hoffmann

Keyword(s):

Capsular Polysaccharide ◽

Group B Streptococcus ◽

Latex Agglutination ◽

Genotype Distribution ◽

Group B Streptococci ◽

The Difference ◽

Group B ◽

Streptococcus A ◽

Precipitation Test ◽

Latex Test

Background This study evaluates two procedures for typing of Streptococcus agalactiae (group B streptococci; GBS) isolates, using retrospective typing data from the period 2010 to 2014 with a commercial latex agglutination test (latex test) and the Lancefield precipitation test (LP test). Furthermore, the genotype distribution of phenotypically non-typable (NT) GBS isolates is presented. We also raise the awareness, that the difference in typing results obtained by phenotypical methods and genotype based methods may have implications on vaccine surveillance in case a GBS vaccine is introduced. Methods A total of 616 clinical GBS isolates from 2010 to 2014 were tested with both a latex test and the LP test. Among these, 66 isolates were genotyped by PCR, including 41 isolates that were phenotypically NT. Results The latex test provided a serotype for 83.8% of the isolates (95% CI [80.7–86.6]) compared to 87.5% (95% CI [84.6–90.0]) obtained by the LP method. The two assays provided identical capsular identification for all sero-typeable isolates (excluding NT isolates). The PCR assay provided a genotype designation to the 41 isolates defined as phenotypically NT isolates. Discussion We found that the latex test showed a slightly lower identification percentage than the LP test. Our recommendation is to use the latex agglutination as the routine primary assay for GBS surveillance, and then use the more labour intensive precipitation test on the NT isolates to increase the serotyping rate. A genotype could be assigned to all the phenotypically NT isolates, however, as a consequence genotyping will overestimate the coverage from possible future capsular polysaccharide based GBS vaccines.

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High Prevalence of Fluoroquinolone-Resistant Group B Streptococci among Clinical Isolates in China and Predominance of Sequence Type 19 with Serotype III

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02317-12 ◽

2013 ◽

Vol 57 (3) ◽

pp. 1538-1541 ◽

Cited By ~ 22

Author(s):

Hui Wang ◽

Chunjiang Zhao ◽

Wenqiang He ◽

Feifei Zhang ◽

Liyan Zhang ◽

...

Keyword(s):

Group B Streptococcus ◽

Sequence Type ◽

Clinical Isolates ◽

Group B Streptococci ◽

High Prevalence ◽

Resistant Group ◽

Group B

ABSTRACTA total of 146 group B streptococcus isolates from 8 cities across China belonged to four serotypes. Serotype Ia was more common in children. A high prevalence of resistance was observed for levofloxacin (37.7%), erythromycin (71.2%), clindamycin, (53.4%), and tetracycline (81.5%). The levofloxacin and clindamycin resistances among the 4 serotypes differed significantly. Eighty percent of fluoroquinolone-resistant isolates belonged to the sequence type 19 (ST19)/serotype III clone, with GyrA-ParC-ParE triple substitutions. This clone carried theerm(B),mef(E), andtet(M) genes.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.12.3504-3508.2001 ◽

2001 ◽

Vol 45 (12) ◽

pp. 3504-3508 ◽

Cited By ~ 103

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.

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Genetic characterization and diversity of Streptococcus agalactiae isolates with macrolide resistance

Journal of Medical Microbiology ◽

10.1099/jmm.0.018176-0 ◽

2010 ◽

Vol 59 (7) ◽

pp. 780-786 ◽

Cited By ~ 13

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.

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Macrolide Resistance Determinants of Invasive and Noninvasive Group B Streptococci in a Turkish Hospital

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.4.1410-1412.2004 ◽

2004 ◽

Vol 48 (4) ◽

pp. 1410-1412 ◽

Cited By ~ 14

Author(s):

Ziya Cibali Acikgoz ◽

Ebru Almayanlar ◽

Sohret Gamberzade ◽

Safiye Gocer

Keyword(s):

Macrolide Resistance ◽

Erythromycin Resistance ◽

Group B Streptococci ◽

Resistance Determinants ◽

Group B

ABSTRACT Macrolide resistance in 156 consecutive group B streptococcal isolates was investigated. Thirty-five isolates (22.4%) had inducible (80%) or constitutive (20%) erythromycin resistance. The genes responsible were erm(B), erm(A) subclass erm(TR), and erm(B) plus erm(TR) in 62.9, 2.9, and 8.6% of isolates, respectively. Nine isolates (25.7%) harbored neither mef nor detectable erm genes.

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Macrolide-resistance, capsular genotyping and associated factors of group B Streptococci colonized pregnant women in Isfahan, Iran

Iranian Journal of Microbiology ◽

10.18502/ijm.v13i2.5979 ◽

2021 ◽

Author(s):

Soodabeh Rostami ◽

Leila Moeineddini ◽

Fereshteh Ghandehari ◽

Marzieh Rahim Khorasani ◽

Parisa Shoaei ◽

...

Keyword(s):

Risk Factors ◽

Pregnant Women ◽

Group B Streptococcus ◽

Multidrug Resistant ◽

Cross Sectional Study ◽

Macrolide Resistance ◽

Capsular Type ◽

Group B Streptococci ◽

Cross Sectional ◽

Group B

Background and Objectives: Group B streptococcus (GBS) can cause severe and invasive infections in pregnant women, infants, and adults. This study aimed to investigate the risk factors of GBS colonization in pregnant women and determine the macrolide resistance and capsular type of isolates. Materials and Methods: In a cross-sectional study, a total of 200 pregnant women were screened for GBS colonization by phenotypic methods. Antibiotic susceptibility pattern of colonizing isolates and ermB, ermTR, mefA/E genes were detected. Also, molecular capsular types of isolates were distinguished. Results: The overall prevalence of colonization of participates with GBS was 13.5%. Statistical analysis showed that there was no association between risk factors and colonization with GBS. The highest resistance was observed to erythromycin (44.4%) followed by clindamycin (29.6%), penicillin, ampicillin, and ceftriaxone (18.5%), levofloxacin (11.1%), and 29.6% isolates were multidrug-resistant. ermTR and mefA/E genes were detected in 37% and 11.1% isolates; respectively and the ermB gene was not detected. The most common capsular type was type Ib (44.4%) followed by type III (40.7%), type II (11.1), and type Ia (3.7%). Conclusion: In the present study, the prevalence of GBS was in the medium range. Resistance to key antibiotic agents was relatively high. Also, capsular serotype Ib was the predominant serotype, which emphasizes the importance of monitoring the molecular typing of the GBS isolates regularly.

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Trends in molecular characteristics and antimicrobial resistance of group B streptococci: a multicenter study in Serbia, 2015–2020

Scientific Reports ◽

10.1038/s41598-020-79354-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dusan Kekic ◽

Ina Gajic ◽

Natasa Opavski ◽

Milan Kojic ◽

Goran Vukotic ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Late Onset ◽

Group B Streptococcus ◽

Neonatal Morbidity ◽

Disease Rate ◽

Molecular Characteristics ◽

Group B Streptococci ◽

Live Births ◽

Invasive Infections ◽

Group B

AbstractGroup B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality. Serbia has not fully implemented preventive measures against GBS neonatal diseases. Therefore, we aimed to assess the maternal GBS colonisation and invasive neonatal disease rate, to reveal the trends of antimicrobial resistance and serotype distribution of GBS from various patient groups. Randomly selected non-invasive (n = 991) and all invasive GBS (n = 80) collected throughout Serbia from 2015 to 2020 were tested for antimicrobial susceptibility, capsular typing, and hvgA detection. Overall, 877/5621 (15.6%) pregnant women were colonised with GBS. Invasive GBS infections incidence in infants (0.18/1000 live births) showed a decreasing trend (0.3 to 0.1/1000 live births). Type III was overrepresented in infants with invasive infections (n = 35, 58.3%), whereas type V predominated among colonised adults (n = 224, 25.5%) and those with noninvasive (n = 37, 32.5%) and invasive infections (n = 8, 40%). The hypervirulent clone III/ST17 was highly associated with invasive infections (n = 28, 35%), particularly late-onset disease (n = 9, 47.4%), showing an increase from 12.3 to 14.8%. The GBS resistance to erythromycin and clindamycin was 26.7% and 22.1%, respectively, with an upward trend. The emergence of the hypervirulent clone III/ST17 and the escalation in GBS resistance highlight an urgent need for continuous monitoring of GBS infections.

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Effect of Urine Latex Agglutination Tests on the Treatment of Children at Risk for Invasive Bacterial Infection

PEDIATRICS ◽

10.1542/peds.96.5.951 ◽

1995 ◽

Vol 96 (5) ◽

pp. 951-954

Author(s):

Penny M. Adcock ◽

Ronald I. Paul ◽

Gary S. Marshall

Keyword(s):

Bacterial Infection ◽

Group B Streptococcus ◽

Latex Agglutination ◽

Patient Treatment ◽

Test Results ◽

Predictive Values ◽

Hospital Patients ◽

Invasive Bacterial Infection ◽

Group B ◽

Site Identification

Background. Identifying febrile children with invasive bacterial infection is difficult in the absence of telltale physical findings. Urine latex agglutination (ULA) tests have been used for rapid, on-site identification of such children. Objectives. To study the performance of ULA tests in identifying children with Haemophilus influenzae, Streptococcus pneumoniae, and group B streptococcus infection and to examine how the results of ULA tests affect patient treatment. Design. Retrospective review. Setting. Urban children's hospital. Patients. All emergency department and hospital patients tested by ULA in 1990, excluding patients in the neonatal units. Results. Of 1629 patients, 36 had positive tests (20 H influenzae, 5 S pneumoniae, and 11 group B streptococcus). Thirteen of these were false positive based on culture results. Although ULA tests demonstrated excellent specificity, their sensitivity was poor. Positive predictive values for bacteremia ranged from 0.346 to 0.600, and negative predictive values ranged from 0.972 to 0.997. The decision to treat with antibiotics was made before ULA test results were available in 19 (53%) of the 36 patients with positive test results. Of 1593 patients with negative test results, 1211 (76%) were admitted to the hospital, and approximately 81% were empirically treated with parenteral antibiotics. Conclusions. In clinical practice, treatment and disposition decisions are frequently made without regard to ULA test results.

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