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Ghia C, Rambhad G. Disease burden due to Group B Streptococcus in the Indian population and the need for a vaccine - a narrative review. Ther Adv Infect Dis 2021; 8:20499361211045253. [PMID: 34540226 PMCID: PMC8445532 DOI: 10.1177/20499361211045253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/23/2021] [Indexed: 11/17/2022] Open
Abstract
Streptococcus agalactiae, a Gram-positive bacterium, causes invasive infection known as Group B streptococcal disease (GBS). It is a leading cause of neonatal death and complications prior to delivery. The burden of GBS is unknown in India despite the high incidence of preterm and stillbirths. In this study, we performed a narrative review of the available literature (published in the last 10 years) on the epidemiology of GBS, using PubMed and Google Scholar, to understand its impact in India and evaluate potential strategies to prevent the disease in the high-risk population, that is, neonates. The review showed that the incidence of early- and late-onset GBS in neonates (per 1000 live births) was in the ranges of 0.090-0.68 and 0.0-0.07 respectively. The overall case fatality rate reported in only one study was 0.63. In pregnant women, the prevalence of GBS colonization was 2-62% and its transmission to their newborns varied from 6.7% to 11.1%. The serotype distribution of GBS is unclear, but some studies reported the distribution of types Ia, Ib, II, III, V, VII among pregnant women in India. The associated risk factors for GBS colonization in pregnant women are unclear but a few studies suggest the role of age and multigravida, while the risk factors in neonates include preterm birth, prolonged rupture of membrane (⩾18 h), maternal fever, obstetric complications, and prolonged labor >18 h. Screening of GBS is not a routine practice in India and intrapartum antibiotics prophylaxis is limited to only in risk conditions to prevent neonatal disease transmission. A few studies also suggest that high birth rate, poor detection methods, and financial constraints limit routine GBS screening in a developing country such as India. Hence, maternal vaccination is the most promising strategy to prevent neonatal GBS and Pfizer's hexavalent GBS conjugate vaccine (GBS6) is being developed for GBS neonatal disease.
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Affiliation(s)
- Canna Ghia
- Pfizer Ltd, The Capital, 1802, 18th Floor, Plot No. C-70, G Block, Bandra Kurla Complex, Bandra (East), Mumbai, Maharashtra 400051, India
| | - Gautam Rambhad
- Pfizer Ltd, The Capital, 1802, 18th Floor, Plot No. C-70, G Block, Bandra Kurla Complex, Bandra (East), Mumbai, 400051, India
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2
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Geteneh A, Kassa T, Alemu Y, Alemu D, Kiros M, Andualem H, Abebe W, Alemayehu T, Alemayehu DH, Mihret A, Mulu A, Mihret W. Enhanced identification of Group B streptococcus in infants with suspected meningitis in Ethiopia. PLoS One 2020; 15:e0242628. [PMID: 33211777 PMCID: PMC7676702 DOI: 10.1371/journal.pone.0242628] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/05/2020] [Indexed: 12/22/2022] Open
Abstract
Meningitis is one of the top ten causes of death among Ethiopian infants. Group B streptococcus (GBS) has emerged as a leading cause of meningitis in neonates and young infants, resulting in high mortality. Despite this, there is no report on GBS associated meningitis in Ethiopia where infant meningitis is common. Hence, the aim of this study was to determine the proportion of GBS associated meningitis among Ethiopian infants. PCR was prospectively used to detect GBS in culture-negative cerebrospinal fluid (CSF) samples, which were collected from infants suspected for meningitis, at Tikur Anbessa specialized hospital, Ethiopia, over a one-year period. GBS was detected by PCR in 63.9% of culture-negative CSF samples. Out of the 46 GBS positive infants, 10.9% (n = 5) of them died. The late onset of GBS (LOGBS) disease was noted to have a poor outcome with 3 LOGBS out of 5 GBS positive samples collected from patients with the final outcome of death. PCR was advantageous in the identification of GBS in culture-negative CSF samples. GBS was detected in 64% of the CSF samples from infants with meningitis compared with zero-detection rate by culture.
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Affiliation(s)
- Alene Geteneh
- Department of Medical Laboratory Science, College of Health Science, Woldia University, Woldia, Ethiopia
- * E-mail:
| | - Tesfaye Kassa
- School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Yared Alemu
- School of Medical Laboratory Science, Jimma University, Jimma, Ethiopia
| | - Derbie Alemu
- Arba Minch College of Health Science, Arba Minch, Ethiopia
| | - Mulugeta Kiros
- Department of Medical Laboratory Science, College of Health Science, Debre Tabor University, Debre Tabor, Ethiopia
| | - Henok Andualem
- Department of Medical Laboratory Science, College of Health Science, Debre Tabor University, Debre Tabor, Ethiopia
| | - Workeabeba Abebe
- School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tinsae Alemayehu
- School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - Adane Mihret
- Armauer Hanson Research Institute, Addis Ababa, Ethiopia
| | | | - Wude Mihret
- Armauer Hanson Research Institute, Addis Ababa, Ethiopia
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3
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Cheng X, Dou Z, Yang J, Gu Y, Liu D, Xie L, Ren T, Liu Y, Yu Z, Tang Y, Wang M. Highly Sensitive and Rapid Identification of Streptococcus agalactiae Based on Multiple Cross Displacement Amplification Coupled With Lateral Flow Biosensor Assay. Front Microbiol 2020; 11:1926. [PMID: 32983004 PMCID: PMC7485445 DOI: 10.3389/fmicb.2020.01926] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 07/22/2020] [Indexed: 12/30/2022] Open
Abstract
Streptococccus agalactiae (S. agalactiae) is an important neonatal pathogen that is associated with mortality and morbidity. Therefore, we developed a rapid, accurate, and sensitive method based on multiple cross displacement amplification (MCDA) for the detection of the target pathogen. Four sets of MCDA primers were designed for targeting the S. agalactiae-specific groEL gene, and one set of MCDA primers with the optimum amplification efficiency was screened for establishing the S. agalactiae-MCDA assay. As a result, the newly-developed assay could be conducted at a fixed temperature (61°C) for only 30 min, eliminating the use of complex instruments. A portable and user-friendly nanoparticle-based lateral flow biosensor (LFB) assay was employed for reporting MCDA results within 2 min. Our results suggested that the detection limit of the S. agalactiae-MCDA-LFB assay is 300 fg per reaction, and no cross-reaction occurred with non-S. agalactiae strains. For 260 vaginal and rectal swabs, the detection rate of the MCDA-LFB assay was 7.7%, which was in accordance with the reference method of enrichment/qPCR, and higher by 4.6% than the CHROMagar culture. Moreover, the total procedure time of the MCDA-LFB assay was around 50 min, including sample collection, template preparation, MCDA reaction, and result reporting. Therefore, the MCDA-LFB assay is superior to enrichment/qPCR and CHROMagar culture and has great promise for point-of-care testing of S. agalactiae from vaginal and rectal swabs of pregnant women in resource-limited settings.
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Affiliation(s)
- Xueqin Cheng
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China.,Hubei Key Laboratory of Embryonic Stem Cell Research, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Zhiqian Dou
- Department of Gynaecology and Obstetrics, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Jing Yang
- Department of Pharmacy, Wuhan General Hospital of the Chinese People's Liberation Army, Wuhan, China
| | - Yulong Gu
- Department of Clinical Laboratory, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Dexi Liu
- Department of Stomatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Ling Xie
- Department of Dermatology, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Tao Ren
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Yan Liu
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Zhifang Yu
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Yijun Tang
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Meifang Wang
- Department of Respiratory and Critical Care Medicine, Taihe Hospital, Hubei University of Medicine, Shiyan, China
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El Shahaway AA, El Maghraby HM, Mohammed HA, Abd Elhady RR, Abdelrhman AA. Diagnostic performance of direct latex agglutination, post-enrichment latex agglutination and culture methods in screening of group B streptococci in late pregnancy: a comparative study. Infect Drug Resist 2019; 12:2583-2588. [PMID: 31692504 PMCID: PMC6710478 DOI: 10.2147/idr.s203543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/16/2019] [Indexed: 11/23/2022] Open
Abstract
Background Group B streptococcus (GBS) is one of the main causes of neonatal sepsis. Purpose Evaluation of the diagnostic performance of direct latex agglutination test (DLA), post-enrichment latex agglutination (LA) test, and direct culture on chromogenic media in rapid identification of GBS carrier in pregnant women in comparison with the conventional post-enrichment CDC-recommended culture method and further to estimate GBS carriage prevalence and its antimicrobial susceptibility. Methods Two hundred pregnant women at gestational age (35–37 weeks) were enrolled. Three low vaginal swabs were obtained from each participant. One swab was directly inoculated into Strep B Select (SBS) agar. The second swab was inoculated in enrichment Lim broth for immunological antigen detection by post-enrichment latex agglutination (5 h and 24 h) and subculture for bacteriological detection. The third swab was used for immunological detection of GBS antigen by direct latex agglutination. The isolated GBS was subjected to antimicrobial susceptibility testing. Results Among 200 pregnant women, 47 (23.5%) were GBS carriers. Considering post-enrichment subculture on SBS medium as a gold standard, the sensitivities for post-enrichment 5 h and 24 h LA were 66% and 95.7%, respectively. However, direct cultivation of the vaginal swabs on SBS medium and DLA recorded 83% and 4.3%, respectively, for sensitivity. All GBS isolates (100%) were sensitive to penicillin G, ampicillin, ceftriaxone, and vancomycin. In contrast, 21.3% and 12.8% of isolated GBS were resistant to erythromycin and clindamycin, respectively. Conclusion Group B streptococcal antigen detection by latex agglutination after 5 h enrichment is a reliable, easy, and relatively rapid method for screening of GBS carriage in pregnant woman not in labor. Latex agglutination after 18–24 h enrichment can be used alternative to standard subculture method for screening GBS carriage.
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Affiliation(s)
- Alia A El Shahaway
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Hanaa M El Maghraby
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Heba A Mohammed
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Rasha R Abd Elhady
- Department of Obstetrics and Gynecology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Amr Ahmed Abdelrhman
- Department of Obstetrics and Gynecology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
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5
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Lin Y, Ye J, Luo M, Hu B, Wu D, Wen J, Yang C, Li Y, Ning Y. Group B Streptococcus DNA Copy Numbers Measured by Digital PCR Correlates with Perinatal Outcomes. Anal Chem 2019; 91:9466-9471. [PMID: 31269399 DOI: 10.1021/acs.analchem.8b05872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Group B Streptococcus (GBS) is a one of the main causes of perinatal disease, yet the method for GBS detection, broth-enriched culture, is time-consuming and has low sensitivity and accuracy. We aimed to develop a GBS digital PCR (GBS-dPCR) assay for detecting GBS colonization. More rapid and accurate detection of GBS colonization could increase GBS diagnosis and treatment closer to delivery. A single-center, retrospective, case-controlled study was performed. A total of 182 rectovaginal swabs from pregnant women, who were undergoing prenatal screening by broth-enriched culture, were evaluated using GBS-dPCR targeting the cfb gene of GBS. Pregnant women with GBS colonization were followed up for correlation analysis between GBS DNA copy numbers and perinatal outcomes. The results of the GBS-dPCR assay were compared to those from the broth-enriched culture, which is the gold standard for GBS detection. The sensitivity and specificity of GBS-dPCR were 98% and 92.5%, respectively. By discrepant result analysis, the specificity of GBS-dPCR was raised to 97.4%. The incidence of premature rupture of membrane (PROM) and neonatal infection were statistically significantly positively correlated with GBS DNA copy numbers. GBS-dPCR has the advantage of directly detecting GBS colonization from swabs with high specificity and sensitivity, while reducing turnaround time (<4 h). Analysis of clinical samples with GBS-dPCR shows that GBS DNA copy numbers are positively correlated with the incidence of PROM and neonatal infection, suggesting that dPCR is a promising method for detection of GBS colonization during pregnancy.
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Affiliation(s)
- Yanqing Lin
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China.,Affiliated Shenzhen Maternity & Healthcare Hospital , Southern Medical University , Shenzhen 518028 , People's Republic of China
| | - Jianbin Ye
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China.,Zhuhai SMU Biomedicine Public Service Platform LLC , Zhuhai 519040 , People's Republic of China
| | - Meiqun Luo
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
| | - Bingxin Hu
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
| | - Danlin Wu
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
| | - Junjie Wen
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
| | - Chuanzhong Yang
- Affiliated Shenzhen Maternity & Healthcare Hospital , Southern Medical University , Shenzhen 518028 , People's Republic of China
| | - Yan Li
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
| | - Yunshan Ning
- School of Laboratory Medicine and Biotechnology , Southern Medical University , Guangzhou 510515 , People's Republic of China
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6
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Comparison of Three Nucleic Acid Amplification Tests and Culture for Detection of Group B Streptococcus from Enrichment Broth. J Clin Microbiol 2019; 57:JCM.01958-18. [PMID: 30944190 PMCID: PMC6535594 DOI: 10.1128/jcm.01958-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/16/2019] [Indexed: 12/17/2022] Open
Abstract
Colonization of the gastrointestinal and genitourinary tracts of pregnant women with group B Streptococcus (GBS) can result in vertical transmission to neonates during labor/delivery. GBS infections in neonates can cause severe complications, such as sepsis, meningitis, and pneumonia. Accurate detection is critical because administration of intrapartum antibiotics can significantly reduce transmission. We compared the clinical sensitivities of three nucleic acid amplification tests (NAATs), the Hologic Panther Fusion GBS, Luminex Aries GBS, and Cepheid Xpert GBS LB assays, to that of the standard of care culture method recommended for GBS screening using 500 vaginal-rectal swab specimens after 18 to 24 h of broth enrichment. We identified 108 positive specimens (21.6%) by culture, while at least 1 of the 3 NAATs was positive for GBS in 155 specimens (31.0%). All 108 specimens positive by culture were also detected by the Panther Fusion assay, while 107/108 (99.1%) were detected by the Cepheid Xpert and Luminex Aries assays. Of the 61 specimens positive by at least 1 NAAT but negative by culture, 24 (39.3%) were positive by all 3 NAATs, suggesting that they represent true positives (TPs). NAATs offer less hands-on time, greater throughput, faster time to result, and potentially greater sensitivity than culture methods, and they should be considered the new gold standard for intrapartum GBS screening.
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7
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Clouse K, Shehabi A, Suleimat AM, Faouri S, Khuri-Bulos N, Al Jammal A, Chappell J, Fortner KB, Chamby AB, Randis TM, Ratner AJ, Aronoff DM, Halasa N. High prevalence of Group B Streptococcus colonization among pregnant women in Amman, Jordan. BMC Pregnancy Childbirth 2019; 19:177. [PMID: 31109301 PMCID: PMC6528311 DOI: 10.1186/s12884-019-2317-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Background Little is known of the burden of Group B Streptococcus (GBS) colonization among pregnant women in Jordan. We conducted a pilot study to determine the prevalence of GBS among pregnant women in Amman, Jordan, where GBS testing is not routine. We also explored GBS serotypes and the performance of a rapid GBS antigen diagnostic test. Methods We collected vaginal-rectal swabs from women who presented for labor and delivery at Al-Bashir Hospital. Three methods were used to identify GBS: Strep B Rapid Test (Creative Diagnostics), blood agar media (Remel) with confirmed with BBL Streptocard acid latex test (Becton Dickinson), and CHROMagar StrepB (Remel). Results were read by a senior microbiologist. We defined our gold standard for GBS-positive as a positive blood agar culture confirmed by latex agglutination and positive CHROMagar. PCR testing determined serotype information. Demographic and clinical data were also collected. Results In April and May 2015, 200 women were enrolled with a median age of 27 years (IQR: 23–32); 89.0% were Jordanian nationals and 71.9% completed secondary school. Median gestational age was 38 weeks (IQR: 37–40); most women reported prenatal care (median 9 visits; IQR: 8–12). Median parity was 2 births (IQR: 1–3). Pre-pregnancy median BMI was 24.1 (IQR: 21.5–28.0) and 14.5% reported an underlying medical condition. Obstetric complications included gestational hypertension (9.5%), gestational diabetes (6.0%), and UTI (53.5%), of which 84.5% reported treatment. Overall, 39 (19.5%) of women were GBS-positive on blood agar media and CHROMagar, while 67 (33.5%) were positive by rapid test (36% sensitivity, 67% specificity). Serotype information was available for 25 (64%) isolates: III (48%), Ia (24%), II (20%), and V (8%). No demographic or clinical differences were noted between GBS+ and GBS-negative women. Conclusions Nearly one in five women presenting for labor in Jordan was colonized with GBS, with serotype group III as the most common. The rapid GBS antigen diagnostic had low sensitivity and specificity. These results support expanded research in the region, including defining GBS resistance patterns, serotyping information, and risk factors. It also emphasizes the need for routine GBS testing and improved rapid GBS diagnostics for developing world settings.
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Affiliation(s)
- Kate Clouse
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, USA. .,Vanderbilt Institute for Global Health, Nashville, TN, USA.
| | | | | | | | | | | | - James Chappell
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kimberly B Fortner
- Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Anna B Chamby
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, NY, USA
| | - Tara M Randis
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, NY, USA
| | - Adam J Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, NY, USA
| | - David M Aronoff
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Natasha Halasa
- Vanderbilt Institute for Global Health, Nashville, TN, USA. .,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
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Guo D, Xi Y, Wang S, Wang Z. Is a positive Christie-Atkinson-Munch-Peterson (CAMP) test sensitive enough for the identification of Streptococcus agalactiae? BMC Infect Dis 2019; 19:7. [PMID: 30606123 PMCID: PMC6318942 DOI: 10.1186/s12879-018-3561-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/27/2018] [Indexed: 11/22/2022] Open
Abstract
Background For a long time, the Christie-Atkinson-Munch-Peterson (CAMP) test has been a standard test for the identification of Streptococcus agalactiae, and a positive result for S.agalactiae has been considered sensitive enough. Methods To confirm whether a positive CAMP test is a requirement for the identification of S.agalactiae, five suspected CAMP-negative S.agalactiae isolates from two hospitals, confirmed as Gram-positive and catalase-negative streptococci, were verified by the CAMP test in three batches of plates from two manufacturers and identified by the Phoenix system, MALDI-TOF MS, the PCR assay and the 16S rDNA gene sequencing. Results All five suspected strains were S.agalactiae, four of which were CAMP-negative and one of which was not S.agalactiae by the PCR assay. Conclusions A positive CAMP test was lacking sensitivity for the identification of S.agalactiae, and the question of whether the cfb gene is worthy of targeting should be further studied.
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Affiliation(s)
- Dacheng Guo
- Institute for Infectious Disease Control and Prevention, Henan Provincial Center for Disease Control and Prevention, Zhengzhou, China
| | - Yu Xi
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Shanmei Wang
- Department of Clinical Laboratory, Henan Provincial People's Hospital, Zhengzhou, China
| | - Zeyu Wang
- R&D Center, Autobio Diagnostics Co. Ltd, Zhengzhou, China.
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Carrillo-Ávila JA, Gutiérrez-Fernández J, González-Espín AI, García-Triviño E, Giménez-Lirola LG. Comparison of qPCR and culture methods for group B Streptococcus colonization detection in pregnant women: evaluation of a new qPCR assay. BMC Infect Dis 2018; 18:305. [PMID: 29976153 PMCID: PMC6034337 DOI: 10.1186/s12879-018-3208-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 06/25/2018] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Streptococcus Group B (GBS) colonization in pregnant women is the most important risk factor for newborn disease due to vertical transmission during delivery. GBS colonization during pregnancy has been implicated as a leading cause of perinatal infections. Traditionally, pregnant women are screened for GBS between 35 and 37 weeks of gestation. However, antenatal culture-based screening yields no information on GBS colonization status and offers low predictive value for GBS colonization at delivery. Numerous assays have been evaluated for GBS screening in an attempt to validate a fast and efficient method. The aim of this study was to compare bacteria isolation by culture and two qPCR techniques, targeting sip and cfb genes, respectively, for detecting colonizing GBS. METHODS Cultures - the gold-standard technique, a previous qPCR technique targeting the sip gene, and a new proposed qPCR assay targeting the cfb gene were evaluated as diagnostic tools on 320 samples. RESULTS Considering cultures as the gold standard, the evaluated qPCR method detected 75 out of 78 samples, representing a sensitivity of 93.58% (95% confidence interval (CI), 90.89-96.27) and specificity of 94.62% (95% CI, 91.78-97.46). However, an additional analysis was performed for true positives that included not only samples showing positives by culture but samples showing positive for both qPCR assays. The sensitivity and specificity were recalculated including these discrepant samples and a total of 89 samples were considered as positive, giving a prevalence of 27.81%. With this new analysis, the qPCR targeting the cfb gene showed a sensitivity of 95.5% (95% CI, 88.65-98.59) and specificity of 99.13% (95% CI, 96.69-99.97). CONCLUSIONS The new qPCR method is a sensitive and specific assay for detecting GBS colonization and represents a valuable tool for identifying candidates for intrapartum antibiotic prophylaxis. Cultures should be retained as the reference and the routine technique because of its specificity and cost analysis ratio, but it would be convenient to introduce PCR techniques to check negative culture samples or when an urgent detection is required to reduce risk of infection among infants.
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Affiliation(s)
- J. A. Carrillo-Ávila
- Laboratorio de Microbiología, Universidad de Granada-Instituto de Investigación Biosanitaria de Granada, Av. de la Investigación n°11, 18071 Granada, Spain
| | - J. Gutiérrez-Fernández
- Laboratorio de Microbiología, Universidad de Granada, Hospital General Virgen de las Nieves- Instituto de Investigación Biosanitaria de Granada, Granada, Spain
| | - A. I. González-Espín
- Hospital Materno Infantil de Jaén, Avenida de Ejército Español s/n, 23007 Jaén, Spain
| | - E. García-Triviño
- Hospital Materno Infantil de Jaén, Avenida de Ejército Español s/n, 23007 Jaén, Spain
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10
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Pinto AM, Pereira TA, Alves V, Araújo A, Lage OM. Incidence and serotype characterisation of Streptococcus agalactiae in a Portuguese hospital. J Clin Pathol 2017; 71:508-513. [PMID: 29180508 DOI: 10.1136/jclinpath-2017-204646] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/16/2017] [Accepted: 11/03/2017] [Indexed: 11/04/2022]
Abstract
AIMS Streptococcus agalactiae, commonly known as group B Streptococcus (GBS), has been recognised as a worldwide causative pathogenic agent of neonatal sepsis, meningitis and pneumonia. To better understand the behaviour of S. agalactiae in pregnant women from a hospital from the North of Portugal, retrospective analyses were performed to describe epidemiological, clinical and microbiological characteristics of the isolates obtained. METHODS Based on laboratorial records and the hospital's patient files, a 6-year retrospective study was performed to analyse S. agalactiae isolates from screened pregnant women between 35 and 37 weeks of gestation and hospitalised neonates from pregnant women between 24 and 41 weeks of gestation admitted in Hospital Pedro Hispano. Serotype characterisation was also performed in 67 GBS strains. RESULTS In 6692 pregnant women between 35 and 37 weeks of gestation screened between 2011 and 2016, a total of 1377 S. agalactiae isolates (21%) were found. A high percentage (40%) of unknown colonisation status among hospitalised neonates from pregnant women between 24 and 41 weeks of gestations was also found. The incidence of neonatal sepsis was 8.7 (95% CI 7.0 to 10.8) cases per 1000 live births. Regarding serotype characterisation, serotype III (22.4%) was the most frequent, followed by serotype Ia (19.4%) and serotypes Ib and V (both with 17.9%). CONCLUSION High epidemiological values of GBS colonisation and incidence were found in this study. In Portugal studies on the epidemiology and behaviour of S. agalactiae remain limited, reinforcing the importance and need for S. agalactiae screening across the country.
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Affiliation(s)
- Ana Mafalda Pinto
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Tamegão Aires Pereira
- Department of Women, Children and Youth, Pediatrics and Neonatology Service, Hospital Pedro Hispano, Matosinhos, Porto, Portugal
| | - Valquíria Alves
- Department of MCDT, Clinical Pathology Service, Hospital Pedro Hispano, Matosinhos, Porto, Portugal
| | | | - Olga Maria Lage
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal.,CIMAR/CIIMAR - Interdisciplinary Centre for Marine and Environmental Research, University of Porto, Porto, Portugal
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Multicenter clinical evaluation of the Xpert GBS LB assay for detection of group B Streptococcus in prenatal screening specimens. J Clin Microbiol 2014; 53:443-8. [PMID: 25411176 DOI: 10.1128/jcm.02598-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neonatal infection with Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis and meningitis in newborns. Recent guidelines have recommended universal screening of all pregnant women to identify those colonized with GBS and administration of peripartum prophylaxis to those identified as carriers to reduce the risk of early-onset GBS disease in neonates. Enriched culture methods are the current standard for prenatal GBS screening; however, the implementation of more sensitive molecular diagnostic tests may be able to further reduce the risk of early-onset GBS infection. We report a clinical evaluation of the Xpert GBS LB assay, a molecular diagnostic test for the identification of GBS from broth-enriched vaginal/rectal specimens obtained during routine prenatal screening. A total of 826 specimens were collected from women undergoing prenatal screening (35 to 37 weeks' gestation) and tested at one of three clinical centers. Each swab specimen was tested directly prior to enrichment using the Xpert GBS assay. Following 18 to 24 h of broth enrichment, each specimen was tested using the Xpert GBS LB assay and the FDA-cleared Smart GBS assay as a molecular diagnostic comparator. Results obtained using all three molecular tests were compared to those for broth-enriched culture as the gold standard. The sensitivity and specificity of the Xpert GBS LB assay were 99.0% and 92.4%, respectively, compared to those for the gold standard culture. The Smart GBS molecular test demonstrated sensitivity and specificity of 96.8% and 95.5%, respectively. The sensitivities of the two broth-enriched molecular methods were superior to those for direct testing of specimens using the Xpert GBS assay, which demonstrated sensitivity and specificity of 85.7% and 96.2%, respectively.
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