scholarly journals Comparison of the AmpliVue, BD Max System, andillumigene Molecular Assays for Detection of Group B Streptococcus in Antenatal Screening Specimens

2015 ◽  
Vol 53 (6) ◽  
pp. 1938-1941 ◽  
Author(s):  
Shelley A. Miller ◽  
Eszter Deak ◽  
Romney Humphries
Keyword(s):  
Group B Streptococcus ◽  
Nucleic Acid Amplification ◽  
Antenatal Screening ◽  
Content Type ◽  
Gene Group ◽  
Molecular Assays ◽  
Culture Sensitivity ◽  
Group B ◽  
Culture Positive ◽  
Broth Enrichment

The performances of the AmpliVue, BD Max, andillumigene group BStreptococcus(GBS) nucleic acid amplification tests (NAATs) were compared to that of enriched culture for detection of GBS in antenatal screening specimens. Two hundred specimens were tested simultaneously with the NAATs, following 18 to 24 h of Lim broth enrichment; 15% of specimens were culture positive for GBS, whereas 31.5% were positive by at least one NAAT. All three NAATs were more sensitive (sensitivity, 90.9 to 100%) than culture (sensitivity, 53.6%).

scholarly journals Comparison of the Panther Fusion and BD MAX Group B Streptococcus (GBS) Assays for Detection of GBS in Prenatal Screening Specimens

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Gregory J. Berry ◽  
Fan Zhang ◽  
Ryhana Manji ◽  
Stefan Juretschko
Keyword(s):  
Late Onset ◽  
Clinical Performance ◽  
Group B Streptococcus ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Kappa Statistics ◽  
Loading Capacity ◽  
Content Type ◽  
Return Visits ◽  
Group B

ABSTRACT Streptococcus agalactiae or group B Streptococcus (GBS) is the cause of early- and late-onset GBS disease in neonates and can present as septicemia, meningitis, and pneumonia. Our objective was to compare the performance of two FDA-approved nucleic acid amplification tests (NAATs), the Panther Fusion and BD MAX systems, for detection of GBS in vaginal-rectal screening specimens. A total of 510 vaginal-rectal prepartum specimens were tested simultaneously in both NAATs following broth enrichment. Assay agreement was calculated using kappa statistics. Overall agreement between assays was 99.0% (505/510; 95% confidence interval, 0.951 to 0.997; kappa = 0.974). Discordant results were retested with both assays and by standard culture. The assays were also compared for workflow characteristics, including time to first results (TFR), total turnaround time (TAT), number of return visits to load additional specimens, and hands-on time (HoT). Using a standard run size of 60 specimens/day, the Panther Fusion assay had a longer TFR (2.4 versus 2.0 h) but showed a shorter overall TAT for all 60 samples (3.98 versus 7.18 h) due to an increased initial sample loading capacity, and it required less labor (35.0 versus 71.3 s/sample) and fewer return visits for loading additional specimens (0 versus 2). The Panther Fusion system also had a larger sample loading capacity (120 versus 24 samples) and greater 8-h throughput (335 versus 96 samples). In summary, the Panther Fusion GBS assay has clinical performance comparable to that of the BD MAX GBS assay but provides a faster TAT, less HoT, and higher throughput.

scholarly journals Detection of Group B Streptococcus Directly from Collected ESwab Samples by Use of the BD Max GBS Assay

2016 ◽  
Vol 54 (6) ◽  
pp. 1660-1663 ◽  
Author(s):  
Suzane Silbert ◽  
Talita T. Rocchetti ◽  
Alicia Gostnell ◽  
Carly Kubasek ◽  
Raymond Widen
Keyword(s):  
Room Temperature ◽  
Group B Streptococcus ◽  
Content Type ◽  
Significant Difference ◽  
Group B ◽  
Broth Enrichment

Group BStreptococcusdetection directly from Copan ESwab collected samples, using the BD Max GBS assay, was evaluated on receipt in the laboratory and after 24 h at room temperature. Results were compared to those using Lim broth enrichment PCR and culture. No significant difference was observed between 24 h ESwab and Lim broth PCRs.

scholarly journals A comparison of GenomEra® GBS PCR and GeneXpert ® GBS PCR assays with culture of GBS performed with and without broth pre-enrichment

2020 ◽  
Vol 39 (10) ◽  
pp. 1945-1950
Author(s):  
S. Y. Nielsen ◽  
J. K. Møller ◽  
M. R. Khalil
Keyword(s):  
Group B Streptococcus ◽  
Microbiology Laboratory ◽  
Reference Standard ◽  
Selective Enrichment ◽  
Standard Culture ◽  
Pcr Assays ◽  
Group B ◽  
Culture Positive ◽  
Culture Negative ◽  
Broth Enrichment

Abstract This study was designed to compare the performance of GeneXpert® and GenomEra® group B streptococcus (GBS) PCR assays, held up against standard culture of GBS performed with and without broth pre-enrichment. In Denmark, the strategy for preventing early onset GBS infection (EOGBS) is risk factor based. Three hundred and sixty six women fulfilling one or more of the criteria for presence of risk factors for EOGBS were prospectively included. Rectovaginal swab samples were taken intrapartum and tested bed-site by the GenomEra® and the GeneXpert® GBS PCR assays and cultured at the microbiology laboratory using Granada agar plates with and without prior growth of sampling material in selective enrichment broth. Among 366 participants tested intrapartum, 99 were GBS-positive by culture, 95 by GenomEra, and 95 by GeneXpert. Compared with culture, the GenomEra and the GeneXpert performed with a sensitivity of 91.8% and 91.7% and a specificity of 98.1% and 97.3%, respectively. A combined reference standard was established by defining true positives as either culture-positive samples or culture-negative samples where both the GeneXpert and the GenomEra GBS PCR assays were positive. Using this, the sensitivity increased to 92.2% and the specificity to 99.6% for GenomEra and to 92.0% and 96.8% for GeneXpert. The use of selective broth enrichment found only three additional GBS culture-positive samples. The performance of the two PCR methods examined was very similar and close to the findings by culture, and both PCR assays are thus applicable as rapid intrapartum bed-site tests.

scholarly journals Evaluation of StrepBSelectChromogenic Medium and the Fast-Track Diagnostics Group B Streptococcus (GBS) Real-Time PCR Assay Compared to Routine Culture for Detection of GBS during Antepartum Screening

2017 ◽  
Vol 55 (7) ◽  
pp. 2137-2142 ◽  
Author(s):  
Deirdre L. Church ◽  
Heather Baxter ◽  
Tracie Lloyd ◽  
Oscar Larios ◽  
Daniel B. Gregson
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Fast Track ◽  
Group B Streptococcus ◽  
Culture Method ◽  
Predictive Values ◽  
Content Type ◽  
Standard Culture ◽  
Group B ◽  
The Cost

ABSTRACTLife-threatening infection in neonates due to group BStreptococcus(GBS) is preventable by screening of near-term pregnant women and treatment at delivery. A total of 295 vaginal-rectal swabs were collected from women attending antepartum clinics in Calgary, Alberta, Canada. GBS colonization was detected by the standard culture method (Strep B Carrot Broth subcultured to blood agar with a neomycin disk) and compared to recovery with Strep Group B Broth (Dalynn Biologicals) subcultured to StrepBSelectchromogenic medium (CM; Bio-Rad Laboratories) and the Fast-Track Diagnostics GBS real-time PCR (quantitative PCR [qPCR]) assay (Phoenix Airmid Biomedical Corp.) performed with broth-enriched samples and the Abbottm2000sp/m2000rt system. A total of 62/295 (21%) women were colonized with GBS; 58 (19.7%) cases were detected by standard culture, while CM and qPCR each found 61 (20.7%) cases. The qPCR and CM were similar in performance, with sensitivities, specificities, and positive and negative predictive values of 98.4 and 98.4%, 99.6 and 99.6%, 98.4 and 98.4%, and 99.6 and 99.6%, respectively, compared to routine culture. Both qPCR and CM would allow more rapid reporting of routine GBS screening results than standard culture. Although the cost per test was similar for standard culture and CM, the routine use of qPCR would cost approximately four times as much as culture-based detection. Laboratories worldwide should consider implementing one of the newer methods for primary GBS testing, depending on the cost limitations of different health care jurisdictions.

scholarly journals Whole-Genome Sequencing Confirms the Coexistence of Different Colonizing Group B Streptococcus Isolates Underscored by CRISPR Typing

2020 ◽  
Vol 9 (5) ◽  
Author(s):  
Clémence Beauruelle ◽  
Maxime Branger ◽  
Thierry Cochard ◽  
Adeline Pastuszka ◽  
Franck Biet ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Draft Genome ◽  
Group B Streptococcus ◽  
Whole Genome ◽  
Industrialized Countries ◽  
Genome Sequences ◽  
Neonatal Infections ◽  
Content Type ◽  
Phylogenetic Affiliation ◽  
Group B

Streptococcus agalactiae is a major pathogen and is the leading cause of neonatal infections in industrialized countries. The diversity of strains isolated from two pregnant women was investigated. Here, we present the draft genome sequences of strains W8A2, W8A6, W10E2, and W10F3, obtained in order to ascertain their phylogenetic affiliation.

scholarly journals Multicenter Diagnostic Accuracy Evaluation of the Luminex Aries Real-Time PCR Assay for Group B Streptococcus Detection in Lim Broth-Enriched Samples

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
D. R. Hernandez ◽  
D. M. Wolk ◽  
K. L. Walker ◽  
S. Young ◽  
R. Dunn ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Enrichment Culture ◽  
Culture Method ◽  
Nucleic Acid Amplification ◽  
Accuracy Evaluation ◽  
Culture Methods ◽  
Assay Sensitivity ◽  
Content Type ◽  
Group B ◽  
Positive Agreement

ABSTRACT The vertical transmission of group B Streptococcus (GBS) strains causing neonatal sepsis is one of the leading reasons for neonatal mortality worldwide. The gold standard for GBS detection is enriched culture with or without the aid of chromogenic agars. Given the high risk for morbidity and mortality in this population, high assay sensitivity is required to prevent the personal and economic costs of GBS disease. Nucleic acid amplification tests (NAATs) allow for objective determination of GBS colonization with a sensitivity and a specificity higher than those of traditional culture methods. In this study, we determined the analytical and clinical performance of the Aries GBS assay compared to those of the enrichment culture method, biochemical identification, and the NAATs used at the study sites. Remnant Lim broth samples were used to perform the Aries assay and reference testing. Upon first testing using enriched culture as the reference standard, the Aries GBS assay identified GBS with a 96.1% sensitivity (95% confidence interval [CI], 91.2 to 98.7%) and a 91.4% specificity (95% CI, 88.8 to 93.6%). The test performed with 100% positive agreement (95% CI, 83.2 to 100%) compared to the results of the BD Max GBS assay and 98.0% positive agreement (95% CI, 89.2 to 99.9%) compared to the results of the Cepheid Xpert GBS LB test. Repeatability and reproducibility were maintained in intra- and interlaboratory testing, regardless of the instrument, module, or user who performed the test. The Aries GBS assay can be set up in less than 5 min and produces results in 2 h. The easy setup, with minimal hands-on time, and high assay sensitivity and specificity make this a useful testing option for GBS screening in prepartum women.

scholarly journals Intrinsic Maturational Neonatal Immune Deficiencies and Susceptibility to Group B Streptococcus Infection

2017 ◽  
Vol 30 (4) ◽  
pp. 973-989 ◽  
Author(s):  
Michelle L. Korir ◽  
Shannon D. Manning ◽  
H. Dele Davies
Keyword(s):  
Immune System ◽  
Group B Streptococcus ◽  
Host Immune System ◽  
Emerging Pathogen ◽  
Content Type ◽  
Birth Canal ◽  
Preventative Measures ◽  
Neonatal Immune System ◽  
Immune Deficiencies ◽  
Group B

SUMMARY Although a normal member of the gastrointestinal and vaginal microbiota, group B Streptococcus (GBS) can also occasionally be the cause of highly invasive neonatal disease and is an emerging pathogen in both elderly and immunocompromised adults. Neonatal GBS infections are typically transmitted from mother to baby either in utero or during passage through the birth canal and can lead to pneumonia, sepsis, and meningitis within the first few months of life. Compared to the adult immune system, the neonatal immune system has a number of deficiencies, making neonates more susceptible to infection. Recognition of GBS by the host immune system triggers an inflammatory response to clear the pathogen. However, GBS has developed several mechanisms to evade the host immune response. A comprehensive understanding of this interplay between GBS and the host immune system will aid in the development of new preventative measures and therapeutics.

scholarly journals Antenatal Screening for Group B Streptococcus in the Setting of Preterm Premature Rupture of Membranes: Empiric versus Culture-based Prophylaxis

2020 ◽  
Vol 10 (01) ◽  
pp. e26-e31
Author(s):  
Leena B. Mithal ◽  
Nirali Shah ◽  
Anna Romanova ◽  
Emily S. Miller
Keyword(s):  
Multivariable Analysis ◽  
Group B Streptococcus ◽  
Preterm Neonates ◽  
Premature Rupture Of Membranes ◽  
Premature Rupture ◽  
Preterm Premature Rupture ◽  
Significant Difference ◽  
Culture Sensitivity ◽  
Intrapartum Antibiotic ◽  
Group B

Abstract Objective Imperfect culture sensitivity and increase of early onset neonatal sepsis (EONS) risk in preterm neonates raise concern that culture-based intrapartum antibiotic prophylaxis (IAP) may be insufficient after preterm premature rupture of membranes (PPROM). Our objective was to compare rates of EONS after empiric versus culture-based IAP in PPROM. Study Design This retrospective cohort study included women with a singleton gestation and PPROM between 23 and 33 weeks. Outcomes after culture-based IAP were compared with empiric IAP. The primary outcome was EONS. Secondary outcomes included group B streptococcus (GBS) bacteremia, bacteremia, and neonatal GBS infection. Bivariable and multivariable logistic analyses were performed. Results Of the 270 women who met inclusion criteria, 136 (50%) had culture-based IAP of whom 36 (26.5%) were GBS positive. There was no significant difference in bacteremia (2.2 vs. 4.5%, p = 0.30), GBS infection (0.8 vs. 0.7%, p = 1.00), or EONS (11.8 vs. 12.7%, p = 0.82) in infants of women with culture-based IAP compared with empiric IAP. Multivariable analysis confirmed a lack of advantage to empiric versus culture-based IAP in EONS risk (adjusted odds ratio [aOR] = 0.82, 95% confidence interval [CI]: 0.44–1.93). Conclusion In pregnancies complicated by PPROM, infants of women who received culture-based IAP had no significant difference in EONS or GBS infection compared with infants of women with empiric IAP.

scholarly journals Serotype Distribution, Population Structure, and Antimicrobial Resistance of Group B Streptococcus Strains Recovered from Colonized Pregnant Women

2016 ◽  
Vol 55 (2) ◽  
pp. 412-422 ◽  
Author(s):  
Sarah Teatero ◽  
Patricia Ferrieri ◽  
Irene Martin ◽  
Walter Demczuk ◽  
Allison McGeer ◽  
...  
Keyword(s):  
Population Structure ◽  
Pregnant Women ◽  
Antimicrobial Agents ◽  
Vaccine Development ◽  
Group B Streptococcus ◽  
Tetracycline Resistance ◽  
The United States ◽  
High Rate ◽  
Content Type ◽  
Group B

ABSTRACTUsing serotyping, multilocus sequence typing, and whole-genome sequencing (WGS) of selected strains, we studied the population structure of 102 group BStreptococcus(GBS) isolates prospectively sampled in 2014 from vaginal/rectal swabs of healthy pregnant women in metropolitan Toronto, Canada. We also determined the susceptibilities of each of the colonizing isolates to penicillin, erythromycin, clindamycin, tetracycline, and other antimicrobial agents. Overall, we observed a high rate of tetracycline resistance (89%) among colonizing GBS isolates. We found resistance to erythromycin in 36% of the strains, and 33% were constitutively or inducibly resistant to clindamycin. The most frequently identified serotypes were III (25%), Ia (23%), and V (19%). Serotype IV accounted for 6% of the colonizing isolates, a rate consistent with that observed among patients with invasive GBS infections in metropolitan Toronto. The majority of serotype IV isolates belonged to sequence type (ST)459, a tetracycline-, erythromycin-, and clindamycin-resistant ST first identified in Minnesota, which is considered to be the main driver of serotype IV GBS expansion in North America. WGS revealed that ST459 isolates from Canada are clonally related to colonizing and invasive ST459 organisms circulating in regions of the United States. We also used WGS to study recombination in selected colonizing strains from metropolitan Toronto, which revealed multiple episodes of capsular switching. Present and future circulating GBS organisms and their genetic diversity may influence GBS vaccine development.

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