Multicenter Evaluation of NeuMoDx Group B Streptococcus Assay on the NeuMoDx 288 Molecular System

ABSTRACT Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in developed countries. Recommendations for antepartum GBS detection include enriched culture with several options for identifying GBS, some of which are time-consuming. To reduce the time for identification and determination of the maternal GBS colonization status, rapid nucleic acid amplification technologies have been developed and commercialized. For rapid detection of GBS, a three-site clinical study was conducted to evaluate the NeuMoDx GBS assay, a real-time PCR test performed for vaginal/rectal swab specimens in Lim broth enrichment culture on the NeuMoDx 288 molecular system (NeuMoDx system); these data were used to a support 510(k) submission. A total of 1,250 eligible remnant samples were prospectively enrolled and tested during the study. The results of the PCR assay were compared to the results of the Centers for Disease Control and Prevention (CDC)-recommended enriched-culture method, which served as the gold standard reference method for the study. The NeuMoDx GBS assay results yielded a sensitivity of 96.9% (95% confidence interval [CI] = 94.1 to 98.4), specificity of 96.0% (95% CI = 94.6 to 97.1), and a total agreement with the reference method of 96.2% (95% CI = 93.8 to 98.3). NeuMoDx GBS assay results were also compared to results obtained using the BD MAX GBS assay on the BD MAX system. The two systems demonstrated a total percent agreement of 98.0% (95% CI = 95.5 to 100.0). The performance of the NeuMoDx GBS assay implemented on the NeuMoDx system compared favorably to the CDC enriched-culture method and to the BD MAX GBS assay.

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

Journal of Clinical Microbiology ◽

10.1128/jcm.01768-17 ◽

2018 ◽

Vol 56 (8) ◽

Cited By ~ 3

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.

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Immunochromatographic Detection of the Group B Streptococcus Antigen from Enrichment Cultures

Clinical and Vaccine Immunology ◽

10.1128/cvi.00171-13 ◽

2013 ◽

Vol 20 (9) ◽

pp. 1381-1387 ◽

Cited By ~ 4

Author(s):

Hidehito Matsui ◽

Juri Kimura ◽

Masato Higashide ◽

Yoshio Takeuchi ◽

Kuniyuki Okue ◽

...

Keyword(s):

Limit Of Detection ◽

Enrichment Culture ◽

False Negative ◽

Group B Streptococcus ◽

Cross Reactivity ◽

Content Type ◽

Enrichment Cultures ◽

Control And Prevention ◽

Reactivity Test ◽

Group B

ABSTRACTGroup BStreptococcus(GBS;Streptococcus agalactiae) is a leading cause of serious neonatal infections. The Centers for Disease Control and Prevention recommends GBS screening for all pregnant women during the 35th to 37th weeks of gestation. Although GBS screening has been performed mainly by the culture-based method, it takes several days to obtain a reliable result. In this study, we developed a rapid immunochromatographic test (ICT) for the detection of GBS-specific surface immunogenic protein in 15 min using an overnight enrichment culture. The ICT was prepared using two anti-Sip monoclonal antibodies. This ICT was able to detect recombinant Sip levels of 0.5 ng/ml, or about 106CFU/ml of GBS cells, in tests with 9 GBS strains of different serotypes. The cross-reactivity test using 26 species of microorganism showed no detectable false-positive result. Reactivity of the ICT with 229 GBS strains showed one false-negative result that was attributable to the production of truncated Sip. Among 260 enrichment cultures of vaginal swabs, 17 produced red to orange pigments in Granada medium, and they were all GBS and Sip positive. Among 219 pigment-negative cultures, 12 were GBS positive and 10 were Sip positive. Two Sip-negative cultures contained GBS cells below the limit of detection by the ICT. Among 207 GBS-negative cultures, only one was Sip positive, which was attributable to GBS cell debris. Thus, the sensitivity and specificity of the ICT appeared to be 93.1% and 99.6%, respectively. The newly developed ICT is readily applicable to clinical use in the detection of GBS.

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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

Journal of Clinical Microbiology ◽

10.1128/jcm.00043-17 ◽

2017 ◽

Vol 55 (7) ◽

pp. 2137-2142 ◽

Cited By ~ 4

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.

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Diagnostic Performance of Various Methodologies for Group B Streptococcus Screening in Pregnant Woman in China

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.651968 ◽

2021 ◽

Vol 11 ◽

Author(s):

Kankan Gao ◽

Qiulian Deng ◽

Lianfen Huang ◽

Chien-Yi Chang ◽

Huamin Zhong ◽

...

Keyword(s):

Group B Streptococcus ◽

Agar Plate ◽

Reference Method ◽

Antigen Detection ◽

The Other ◽

Blood Agar ◽

Blood Agar Plate ◽

Chromogenic Agar ◽

Group B ◽

Detection Reagent

Maternal vaginal/rectal colonization of group B streptococcus (GBS) is a main risk for neonatal invasive infection. Efficient determination of GBS colonization in pregnant women is crucial. This study aimed to investigate the prevalence of GBS carriage and evaluate the diagnostic performance of six methodologies for GBS screening conducted in China, including blood agar plate, liquid chromogenic medium, and loop-mediated isothermal amplification (LAMP) without pre-enrichment, chromogenic agar plate with pre-enrichment, and GBS antigen detection without and with pre-enrichment in comparison with the standard reference method (Lim broth-enriched subculture with plating on 5% sheep blood agar). Vaginal/rectal swabs were collected from 1,281 pregnant women at 35–37 weeks of gestation. Of them, 309 were taken in triplicate, one for Lim broth-enriched subculture, one for blood agar plate, and the third for GBS antigen detection (Reagent W); 177 were acquired in duplicate, one for Lim broth-enriched subculture and the other for GBS antigen detection (Reagent H); 502 were obtained in duplicate, one for Lim broth-enriched subculture and the other for liquid chromogenic medium; 158 were collected in duplicate, one for Lim broth-enriched subculture and the other for LAMP; and 135 were inoculated in Lim broth-enriched for GBS antigen detection (Reagent W) and subculture with chromogenic agar plate and 5% blood agar plate. The overall prevalence of GBS carriage was 10.1% (130/1,281, 95% CI: 8.5–12.1%) according to the standard reference method. Compared with the standard reference method, the LAMP had excellent performance of sensitivity (100%, 95%CI: 83.4–100%), specificity (94%, 95%CI: 88.1–97.1%), and Yoden index (0.940); as well as the blood agar plate with sensitivity (81.5%, 95%CI: 61.3–93.0%), specificity (100%, 95%CI: 98.3–100.0%), and Yoden index (0.815). The other four methods were not sufficient to reach the threshold in terms of sensitivity or specificity compared to the standard reference method. Furthermore, for LAMP, results can be obtained within 0.5–1 h, while for blood agar plate, which needed 24–48 h, and further identification was required. Our data suggested that the performance of LAMP was highly comparable to the standard Lim broth-enriched subculture and LAMP is considered as an alternative for fast and accurate GBS screening.

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To screen or not to screen women for Group B Streptococcus (Streptococcus agalactiae) to prevent early onset sepsis in newborns: recent advances in the unresolved debate

Therapeutic Advances in Infectious Disease ◽

10.1177/2049936120942424 ◽

2020 ◽

Vol 7 ◽

pp. 204993612094242

Author(s):

Guduru Gopal Rao ◽

Priya Khanna

Keyword(s):

Risk Factor ◽

Antimicrobial Resistance ◽

Low Income ◽

Streptococcus Agalactiae ◽

Early Onset ◽

Group B Streptococcus ◽

Developed Countries ◽

Low Income Countries ◽

Early Onset Sepsis ◽

Group B

Streptococcus agalactiae, also known as Group B streptococcus (GBS) is the commonest cause of early onset sepsis in newborns in developed high-income countries. Intrapartum antimicrobial (antibiotic) prophylaxis (IAP) is recognized to be highly effective in preventing early onset Group B sepsis (EOGBS) in newborns. The key controversy is about the strategy that should be used to identify mothers who should receive IAP. There are two strategies that are followed in developed countries: screening-based or risk-factor-based identification of women requiring IAP. The debate regarding which of the two approaches is better has intensified in the recent years with concerns about antimicrobial resistance, effect on newborn’s microbiome and other adverse effects. In this review, we have discussed some of the key research papers published in the period 2015–2019 that have addressed the relative merits and disadvantages of screening versus risk-factor-based identification of women requiring IAP. Although screening-based IAP appears to be more efficacious than risk-based IAP, IAP-based prevention has several limitations including ineffectiveness in prevention of late-onset GBS infection in babies, premature and still births, impact of IAP on neonatal microbiota, emergence of antimicrobial resistance and difficulties in implementing IAP-based strategies in middle and low income countries. Alternative strategies, principally maternal immunization against GBS would circumvent use of IAP. However, no licensed vaccines are currently available for use.

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

Journal of Clinical Microbiology ◽

10.1128/jcm.01034-19 ◽

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.

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Antibiotic susceptibility pattern of group B streptococcal isolates from maternal genital tract

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20193035 ◽

2019 ◽

Vol 8 (7) ◽

pp. 2738

Author(s):

Vijayan Sharmila ◽

Thirunavukkarasu Arun Babu

Keyword(s):

Pregnant Women ◽

Antibiotic Susceptibility ◽

Group B Streptococcus ◽

Antibiotic Sensitivity ◽

Developed Countries ◽

Susceptibility Pattern ◽

Antibiotic Susceptibility Pattern ◽

Sensitivity Pattern ◽

Prevention And Treatment ◽

Group B

Background: Group B streptococcus (GBS) is one of the important cause of early onset neonatal sepsis in developed countries leading to increased neonatal morbidity and mortality. Penicillin and Ampicillin are the drugs of choice for prevention of GBS infections. Antibiotic resistance amongst GBS isolates is an emerging health problem affecting neonates. Hence, this study was performed to determine the antibiotic susceptibility pattern of Group B Streptococcus (GBS) in a population of pregnant women.Methods: A prospective study was done to screen pregnant women for vaginal and rectal GBS colonization during their regular visits to antenatal clinic. Todd-Hewitt broth, an enrichment medium for GBS was used for isolation. The antibiotic susceptibility pattern of the isolates were studied. Results: A total of 300 pregnant women were screened for GBS colonization. GBS colonization rate in our study was 2.3%. The antibiotic susceptibility pattern of the isolates revealed that none of the isolates were resistant to penicillin or clindamycin, while resistance was noted to erythromycin (14.3%) and tetracycline (71.4%).Conclusions: GBS continues to remain sensitive to Penicillin which is the drug of choice for prevention and treatment of GBS. Consistent surveillance of antibiotic sensitivity pattern of GBS as well as for other organisms implicated in new born sepsis and maternal infections is required to formulate guidelines for prevention and treatment.

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Perinatal Group B Streptococcal Disease: A Summary of Revised Guidelines from the Centers for Disease Control

Neonatal Network The Journal of Neonatal Nursing ◽

10.1891/0730-0832.22.1.23 ◽

2003 ◽

Vol 22 (1) ◽

pp. 23-28

Author(s):

Jeanette Zaichkin

Keyword(s):

Disease Control ◽

Group B Streptococcus ◽

Morbidity And Mortality ◽

Mortality Weekly Report ◽

American Academy Of Pediatrics ◽

Control And Prevention ◽

Complete Report ◽

Group B Streptococcal Disease ◽

Centers For Disease Control ◽

Group B

Recommendations for prevention of perinatal Group B Streptococcus (GBS) were issued in 1996 by the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention (CDC), followed in 1997 by the American Academy of Pediatrics (AAP). Although increased prevention activities during the 1990s resulted in a striking decline in incidence, GBS disease remains a leading infectious cause of morbidity and mortality among newborns in the U.S. Using available evidence and expert opinion, the CDC issued revised guidelines in August 2002 that replace the 1996 recommendations. This article, taken directly from the Morbidity and Mortality Weekly Report (August 16, 2002), presents a summary of the revised recommendations most applicable to neonatal nursing. The complete report is available at http://www.cdc.gov/mmwr/PDF/RR/RR5111.pdf.

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Comparison of Various Culture Methods for Isolation of Group B Streptococcus from Intrapartum Vaginal Colonization

Journal of Laboratory Physicians ◽

10.4103/0974-2727.115938 ◽

2013 ◽

Vol 5 (01) ◽

pp. 42-45 ◽

Cited By ~ 2

Author(s):

Kavitha P Konikkara ◽

Shrikala Baliga ◽

Suchitra M Shenoy ◽

B Bharati

Keyword(s):

Pregnant Women ◽

Group B Streptococcus ◽

Culture Method ◽

Sheep Blood Agar ◽

Blood Agar ◽

Third Trimester ◽

Sheep Blood ◽

Vaginal Colonization ◽

Vaginal Swabs ◽

Group B

ABSTRACT Aims: Group B Streptococcus (GBS) is one of the most common causes of neonatal sepsis throughout the world. Reports of vaginal colonization of GBS in India are few and variable. A study was conducted on pregnant women in a tertiary care hospital to compare various methods for isolation of GBS, to study the prevalence of GBS in pregnant women in third trimester, and to determine risk factors for GBS colonization. Settings and Design: Observational descriptive study. Materials and Methods: High vaginal swabs from 150 pregnant women in their third trimester were used to compare three methods for isolation of GBS viz. direct culture on 5% Sheep Blood agar, direct culture on selective Columbia Blood Agar and culture in LIM enrichment broth with subsequent culture on 5% Sheep Blood agar. A history of associated risk factors was also taken. Statistical Analysis Used: Statistical analysis was performed by Chi–square test. Results: Isolation was best from LIM enrichment broth with subsequent culture on 5% Sheep Blood Agar. Prevalence of GBS colonization by using culture method was 12.67%. Most frequently associated risk factor was intrapartum fever (42.11%). Conclusions: Standard Culture Method using LIM enrichment should be adopted as standard practice for isolation of GBS from vaginal swabs.

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