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Costa SC, Machado AP, Teixeira C, Cerqueira L, Rodrigues T, Ribeiro M, Moucho M. Group B Streptococcus rectovaginal colonization screening on term pregnancies: culture or polymerase chain reaction? J Matern Fetal Neonatal Med 2023; 36:2262078. [PMID: 37766418 DOI: 10.1080/14767058.2023.2262078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 09/18/2023] [Indexed: 09/29/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate if screening Group B Streptococcus colonization by intrapartum polymerase chain reaction could improve intrapartum administration of antibiotic prophylaxis, compared with antepartum culture screening and analyze the sensitivity and specificity of polymerase chain reaction test. METHODS 198 pregnant women with Group B Streptococcus colonization antepartum culture screening were included. When they arrived at hospital for delivery, two rectovaginal swabs were collected: for culture and polymerase chain reaction method. RESULTS The rate of Group B Streptococcus colonization antepartum detected by culture was 16.7%; at delivery was 17.2% when detected by culture and 19.7% using polymerase chain reaction method. The rate of inconclusive polymerase chain reaction tests was 0.5%. Considering intrapartum culture screening as gold standard, sensitivity and specificity of polymerase chain reaction test for intrapartum Group B Streptococcus colonization was 97.1% and 95.7%, respectively. The global rate of discordance between antepartum and intrapartum Group B Streptococcus colonization was 6.6%. The rate of women not treated with intrapartum antibiotic prophylaxis in the setting of positive intrapartum culture was significantly lower using intrapartum polymerase chain reaction test (0.5%) than with antepartum culture method (3.5%, p = 0.035). CONCLUSION The use of intrapartum antibiotic prophylaxis can be more efficient when screening Group B Streptococcus colonization intrapartum by polymerase chain reaction test. Polymerase chain reaction method had a good performance in our study, with high sensitivity and specificity.
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Affiliation(s)
- Susana Correia Costa
- Serviço de Obstetrícia, Unidade Autónoma de Gestão da Mulher e da Criança, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Ana Paula Machado
- Serviço de Obstetrícia, Unidade Autónoma de Gestão da Mulher e da Criança, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Cláudia Teixeira
- Serviço de Patologia Clínica, Unidade Autónoma de Gestão dos Meios Complementares de Diagnóstico e Terapêutica, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Luísa Cerqueira
- Serviço de Obstetrícia, Unidade Autónoma de Gestão da Mulher e da Criança, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Teresa Rodrigues
- Serviço de Obstetrícia, Unidade Autónoma de Gestão da Mulher e da Criança, Centro Hospitalar Universitário São João, Porto, Portugal
- EPIUnit, Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal
- Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Manuela Ribeiro
- Serviço de Patologia Clínica, Unidade Autónoma de Gestão dos Meios Complementares de Diagnóstico e Terapêutica, Centro Hospitalar Universitário São João, Porto, Portugal
| | - Marina Moucho
- Serviço de Obstetrícia, Unidade Autónoma de Gestão da Mulher e da Criança, Centro Hospitalar Universitário São João, Porto, Portugal
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Kallapur MG, Ghanchi NK, Harakuni SU, Somannavar MS, Ahmed I, Fogleman E, Hwang K, Kim J, Saleem S, Goudar SS, Tikmani SS, Dhaded SM, Guruprasad G, Yasmin H, Yogeshkumar S, McClure EM, Goldenberg RL. Group B streptococcal prevalence in internal organs and placentas of deceased neonates and stillbirths in South Asia. BJOG 2023; 130 Suppl 3:53-60. [PMID: 37530593 DOI: 10.1111/1471-0528.17614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/30/2023] [Indexed: 08/03/2023]
Abstract
OBJECTIVE Group B streptococcus (GBS) has been associated with adverse pregnancy outcomes, but few prospective studies have assessed its prevalence in low- and middle-income country settings. We sought to evaluate the prevalence of GBS by polymerase chain reaction (PCR) in internal organ tissues and placentas of deceased neonates and stillbirths. DESIGN This was a prospective, observational study. SETTING The study was conducted in hospitals in India and Pakistan. POPULATION Pregnant women with stillbirths or preterm births were recruited at delivery, as was a group of women with term, live births, to serve as a control group. METHODS A rectovaginal culture was collected from the women in Pakistan to assess GBS carriage. Using PCR, we evaluated GBS in various tissues of stillbirths and deceased neonates and their placentas, as well as the placentas of live-born preterm and term control infants. MAIN OUTCOME MEASURES GBS identified by PCR in various tissues and the placentas; rate of stillbirths and 28-day neonatal deaths. RESULTS The most obvious finding from this series of analyses from India and Pakistan was that no matter the country, the condition of the subject, the tissue studied or the methodology used, the prevalence of GBS was low, generally ranging between 3% and 6%. Among the risk factors evaluated, only GBS positivity in primigravidae was increased. CONCLUSIONS GBS diagnosed by PCR was identified in <6% of internal organs of stillbirths and neonatal deaths, and their placentas, and control groups in South Asian sites. This is consistent with other reports from South Asia and is lower than the reported GBS rates from the USA, Europe and Africa.
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Affiliation(s)
- Mangala G Kallapur
- Bapuji Educational Association's J.J.M. Medical College, Davangere, Karnataka, India
| | | | - Sheetal U Harakuni
- Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
| | - Manjunath S Somannavar
- Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
| | | | | | - Kay Hwang
- RTI International, Durham, North Carolina, USA
| | - Jean Kim
- RTI International, Durham, North Carolina, USA
| | | | - Shivaprasad S Goudar
- Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
| | | | - Sangappa M Dhaded
- Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
| | - Gowdar Guruprasad
- Bapuji Educational Association's J.J.M. Medical College, Davangere, Karnataka, India
| | | | - S Yogeshkumar
- Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India
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Dilrukshi N, Kottahachchi J, Dissanayake T, Fernando N. Antibiotic Sensitivity of Group B Streptococcus from Pregnant Mothers and Its Association with Resistance Genes. Med Princ Pract 2023; 32:126-132. [PMID: 37023724 PMCID: PMC10319089 DOI: 10.1159/000530525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 03/30/2023] [Indexed: 04/08/2023] Open
Abstract
OBJECTIVE This study assessed the antibiotic susceptibility and characterized antibiotic resistance genes of group B Streptococcus (GBS) isolates from selected tertiary care hospitals in Western Province, Sri Lanka. METHODS A descriptive cross-sectional study was carried out to determine antibiotic sensitivity of GBS among 175 pregnant women of >35 weeks of gestation attending antenatal clinics in four teaching hospitals. Low vaginal and rectal swabs were collected separately, and GBS was identified by standard microbiological methods. Antibiotic sensitivity and minimum inhibitory concentration (MIC) were performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. DNA was extracted from culture isolates, and antibiotic-resistant genes were identified by polymerase chain reaction using ermB, ermTR, mefA, and linB genes. RESULTS GBS colonization in the study sample was 25.7% (45/175) with detection rate of 22.9% (40/175) and 2.9% (5/175) in vaginal and rectal samples, respectively. All isolates were susceptible to penicillin with an MIC range of 0.03-0.12 μg/mL. Six isolates (13.3%) were intermediate, and 11 isolates (24.4%) were resistant to erythromycin. There were 5 intermediately resistant isolates (11.1%) and 10 resistant isolates (22.2%) for clindamycin. Of them, seven had inducible clindamycin resistance (iMLSB). MIC range of erythromycin was 0.03-0.32 μg/mL and that of clindamycin was 0.06-0.32 μg/mL. ermB gene was detected in 7 (15.5%). ermTR gene was found in 16 (35.6%) and was significantly associated with iMLSB phenotype (p = 0.005). mefA gene was detected in two (4.4%) isolates, while linB gene was not detected in tested isolates. CONCLUSION All isolates were sensitive to penicillin, and the most prevalent resistance genotype was ermTR in the study population.
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Affiliation(s)
- Niluka Dilrukshi
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
- Medical Research Institute, Colombo, Sri Lanka
| | - Jananie Kottahachchi
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Thushari Dissanayake
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Neluka Fernando
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
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An Application of Real-Time PCR and CDC Protocol May Significantly Reduce the Incidence of Streptococcus agalactiae Infections among Neonates. Pathogens 2022; 11:pathogens11091064. [PMID: 36145496 PMCID: PMC9502553 DOI: 10.3390/pathogens11091064] [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: 08/24/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
Streptococcus agalactiae is an important human opportunistic pathogen, especially infectious for pregnant women and neonates. This pathogen belongs to beta hemolytic Streptococcus spp. representatives and accounts for a significant part of early infections in newborns, including serious life-threatening infections. This research investigated the usefulness of Centers for Disease Control and Prevention (CDC) protocol for S. agalactiae DNA detection in 250 samples of recto-vaginal swabs collected from pregnant women (at 35-37 weeks of gestation) and pre-cultured overnight in liquid medium. With an application of the CDC protocol-based real-time PCR, the cfb gene was detected in 68 (27.2%) samples compared to 41 (16.4%) for the standard culture-based methodology. The applied molecular method presented high sensitivity (100.0%) and specificity (87.1%). Therefore, it allowed for more precise detection of S. agalactiae bacteria, compared to the reference diagnostic method, culture on solid media with the following strain identification. The increased sensitivity of GBS detection may result in a reduced number of infections in newborns and leads to more targeted antimicrobial prophylaxis therapy of GBS infections in pregnant women. In addition, the use of the molecular method allows for a significant reduction in the time needed to obtain a result for GBS detection, and interpretation of the results is relatively simple. Therefore, it enables a faster intervention in case of a necessity of an antibiotic therapy introduction in pregnant women whose GBS status is unknown at the time of delivery.
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Dilrukshi GN, Kottahachchi J, Dissanayake DMBT, Pathiraja RP, Karunasingha J, Sampath MKA, Vidanage UA, Fernando SSN. Group B Streptococcus colonisation and their antimicrobial susceptibility among pregnant women attending antenatal clinics in tertiary care hospitals in the Western Province of Sri Lanka. J OBSTET GYNAECOL 2020; 41:1-6. [PMID: 32172646 DOI: 10.1080/01443615.2020.1716313] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The proportion of Group B Streptococcus (GBS) colonisation in pregnant women >35 weeks of gestation was 18% and 49% by culture and real-time PCR respectively in selected hospitals from the Western Province of Sri Lanka. A Descriptive cross-sectional study was conducted from January to April 2019. Two low vaginal and rectal swabs were collected from 100 pregnant women. Identification of GBS was done by culture and real-time PCR. GBS isolates were found to be sensitive to penicillin, ampicillin, cefotaxime, vancomycin, while 5 and 4 isolates out of 18 were resistant to erythromycin and clindamycin, respectively. Further, there was a significant association between GBS colonisation and a history of vaginal discharge and unemployment.IMPACT STATEMENTWhat is already known on this subject? Prevalence of GBS colonisation in the vagina and rectum of pregnant women in developing countries ranges from 8.5% to 22%. The Conventional method of culture has been considered the gold standard for diagnosis, however, the culture method does not give positive results for all cases of GBS. Polymerase chain reaction (PCR) has been found to be more sensitive for the detection of GBS than culture. In Sri Lanka, ante-natal screening for GBS is not practiced as the prevalence of GBS is still unlcear due to non-availably of data. Only a few scattered studies have been conducted using culture in Sri Lanka. Thus there is an urgent need to determine the magnitude of the GBS colonisers of ante-natal women in order to set up guidelines for screening and management of GBS.What do the results of this study add? In this study, the overall GBS colonisation rate which was detected using both culture and PCR was 50% in Western Province of Sri Lanka. That was a high figure when compared to the figures which were detected previously in Sri Lanka using only conventional culture methods. The risk factors for GBS colonisation were found to have a significant relationship with the history of abnormal vaginal discharge. Further, it was found that when Candida species coexisted with GBS, the existence of GBS was enhanced. Penicillin remains the antibiotic of choice for GBS.What are the implications of these findings for clinical practice and/or further research? This study emphasises the importance of establishing national policies for screening of pregnant women of >35 weeks of gestation to reduce the risk of neonatal infection. Further, it gives an insight into the options of antibiotics that can be used for treatment of these GBS colonisers from Sri Lanka.
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Affiliation(s)
- G N Dilrukshi
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka.,School of Medical Laboratory Technology, Medical Research Institute, Colombo, Sri Lanka
| | - J Kottahachchi
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
| | - D M B T Dissanayake
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
| | - R P Pathiraja
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
| | | | - M K A Sampath
- Center for Kidney Research, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
| | - U A Vidanage
- Castle Street Hospital for Women, Colombo, Sri Lanka
| | - S S N Fernando
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura, Sri Lanka
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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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Assessment of conventional PCR and real-time PCR compared to the gold standard method for screening Streptococcus agalactiae in pregnant women. Braz J Infect Dis 2018; 22:449-454. [PMID: 30471244 PMCID: PMC9425650 DOI: 10.1016/j.bjid.2018.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 05/11/2018] [Accepted: 09/13/2018] [Indexed: 11/23/2022] Open
Abstract
Group B Streptococcus is a causative agent of invasive neonatal infections. Maternal colonization by Streptococcus agalactiae is a necessary condition for vertical transmission, with efficient screening of pregnant women playing an essential role in the prevention of neonatal infections. In this study, we aimed to compare the performance of conventional polymerase chain reaction and real-time PCR assays as screening methods for S. agalactiae in pregnant women against the microbiological culture method considered as the gold-standard. A total of 130 samples from pregnant women were analyzed for sensitivity, specificity, positive predictive value, and negative predictive value. Statistical analysis was performed using the SPSS software, version 20.0. The verified colonization rate was 3.8% with the gold-standard, 17.7% with conventional PCR assay, and 29.2% with the real-time PCR test. The trials with conventional PCR and real-time PCR had a sensitivity of 100% and a specificity of 85.6% and 73.6%, respectively. The real-time PCR assay had a better performance compared to the gold-standard and a greater detection rate of colonization by S. agalactiae compared to conventional PCR assay. With its quick results, it would be suitable for using in routine screenings, contributing to the optimization of preventive approaches to neonatal S. agalactiae infection.
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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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Otaguiri ES, Morguette AEB, Morey AT, Tavares ER, Kerbauy G, de Almeida Torres RSL, Chaves Júnior M, Tognim MCB, Góes VM, Krieger MA, Perugini MRE, Yamauchi LM, Yamada-Ogatta SF. Development of a melting-curve based multiplex real-time PCR assay for simultaneous detection of Streptococcus agalactiae and genes encoding resistance to macrolides and lincosamides. BMC Pregnancy Childbirth 2018; 18:126. [PMID: 29724169 PMCID: PMC5934892 DOI: 10.1186/s12884-018-1774-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/25/2018] [Indexed: 01/25/2023] Open
Abstract
Background Streptococcus agalactiae or Group B Streptococcus (GBS) remains the leading cause of infections in newborns worldwilde. Prenatal GBS screening of pregnant women for vaginal-rectal colonization is recommended in many countries to manage appropriate intrapartum antimicrobial prophylaxis for those identified as carriers. In this study, a novel melting-curve based multiplex real-time PCR assay for the simultaneous detection of GBS and macrolide and lincosamide resistance markers was developed. The usefulness of the assay was evaluated for rapid and accurate prenatal GBS screening. Methods One hundred two pregnant women who were at 35–37 weeks of gestation were enrolled in this study. The analytical performance of the multiplex real-time PCR was first tested using a panel of reference and clinical bacterial and fungal strains. To test the clinical performance, vaginal-rectal swabs were obtained from pregnant women who were seen at the teaching hospital for regular prenatal care. The results of real-time were compared with those obtained from microbiological analyses. Results The real-time PCR assay showed 100% specificity and a limit of detection of 104 colony forming units equivalent per reaction. The prevalence of GBS colonization among the population studied was 15.7% (16/102) based on a positive culture and the real-time PCR results. Agreement between the two assays was found for 11 (68.75%) GBS colonized women. Using the culture-based results as a reference, the multiplex real-time PCR had a sensitivity of 91.7% (11/12, CI 59.7–99.6%), a specificity of 95.5% (86/90, CI 89.8–98.7%), a positive predictive value of 73.3% (11/15, CI 44.8–91.1%) and a negative predictive value of 98.9% (86/87, CI 92.9–99.9%). Conclusion The multiplex real-time PCR is a rapid, affordable and sensitive assay for direct detection of GBS in vaginal-rectal swabs. Electronic supplementary material The online version of this article (10.1186/s12884-018-1774-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eliane Saori Otaguiri
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Ana Elisa Belotto Morguette
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Alexandre Tadachi Morey
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Eliandro Reis Tavares
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Gilselena Kerbauy
- Departamento de Enfermagem, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Rosângela S L de Almeida Torres
- Laboratory of Bacteriology, Epidemiology Laboratory and Disease Control Division, Laboratório Central do Estado do Paraná - LACEN, Curitiba, PR, Brazil
| | - Mauricio Chaves Júnior
- Departamento de Medicina, Hospital Universitário de Maringá, Universidade Estadual de Maringá, Maringá, Brazil
| | | | | | | | - Marcia Regina Eches Perugini
- Departamento de Patologia, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Lucy Megumi Yamauchi
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | - Sueli Fumie Yamada-Ogatta
- Departamento de Microbiologia, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, Paraná, Brazil. .,Departamento de Microbiologia, Universidade Estadual de Londrina, Centro de Ciências Biológicas, Rodovia Celso Garcia Cid, PR 445, km 380. CEP, Londrina, 86057-970, Brazil.
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Park SY, Kim SY, Choi WJ, Kim SH, Hong SG. Diagnostic Accuracy and Detection Rate of Real-Time PCR for Detection of Group B Streptococcal Colonization in Pregnant Women: Systemic Review of Literature and Meta-Analysis. ANNALS OF CLINICAL MICROBIOLOGY 2017. [DOI: 10.5145/acm.2017.20.2.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Sun Young Park
- Division of New Health Technology Assessment, National Evidence-Based Healthcare Collaborating Agency, Seoul, Korea
| | - So Young Kim
- Division of New Health Technology Assessment, National Evidence-Based Healthcare Collaborating Agency, Seoul, Korea
| | - Won Jung Choi
- Division of New Health Technology Assessment, National Evidence-Based Healthcare Collaborating Agency, Seoul, Korea
| | - Seok-Hyun Kim
- Division of New Health Technology Assessment, National Evidence-Based Healthcare Collaborating Agency, Seoul, Korea
| | - Seong Geun Hong
- Department of Laboratory Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea
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Rapid Detection of Streptococcus agalactiae Infection Using a Loop-Mediated Isothermal Amplification Method. Jundishapur J Microbiol 2016. [DOI: 10.5812/jjm.37171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Burke RM, McKenna JP, Cox C, Coyle PV, Shields MD, Fairley DJ. A comparison of different pre-lysis methods and extraction kits for recovery of Streptococcus agalacticae (Lancefield group B Streptococcus) DNA from whole blood. J Microbiol Methods 2016; 129:103-108. [DOI: 10.1016/j.mimet.2016.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 10/21/2022]
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Clarke C, O'Connor L, Carré-Skinner H, Piepenburg O, Smith TJ. Development and performance evaluation of a recombinase polymerase amplification assay for the rapid detection of group B streptococcus. BMC Microbiol 2016; 16:221. [PMID: 27658382 PMCID: PMC5034592 DOI: 10.1186/s12866-016-0836-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/13/2016] [Indexed: 11/15/2022] Open
Abstract
Background Despite the implementation of prevention guidelines, group B Streptococcal (GBS) infection remains a leading cause of sepsis, pneumonia, and meningitis, resulting in significant neonatal morbidity and mortality. Preventive approaches that identify women at risk of transmitting GBS have reduced the incidence of neonatal GBS disease, and dramatically decreased the associated mortality rates. However, there is an on-going requirement for a near-patient diagnostic test for GBS that can be carried out at the time of delivery, ideally in the labour ward setting, particularly for women of unknown GBS colonisation status at the time of delivery. Methods In this study, a Recombinase Polymerase Amplification (RPA) assay was developed and performance evaluated for the detection of group B Streptococcus in vaginal swabs. The assay uses the cAMP factor (cfb) gene of GBS as the target gene. The analytical performance of the assay was evaluated by testing a panel of GBS reference strains and clinical isolates, and non-GBS organisms. The limit of detection was determined and the clinical performance was evaluated by testing 124 vaginal swabs from women with both GBS positive and negative status. Results Based on specificity testing carried out the assay was shown to be specific for the target of interest. The limit of detection of the assay was shown to be between six and 12 genome copies and was comparable to that of a real-time PCR assay, both achieving a limit of detection below 12.5 genome copies. The performance of both assays when applied to clinical samples was identical. Conclusion A specific, sensitive RPA assay for GBS was developed. The performance of the assay for testing of clinical samples is within the acceptable range. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0836-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christina Clarke
- Molecular Diagnostics Research Group, School of Natural Sciences, National Centre for Biomedical Engineering Science (NCBES), National University of Ireland, Galway, Ireland
| | - Louise O'Connor
- Molecular Diagnostics Research Group, School of Natural Sciences, National Centre for Biomedical Engineering Science (NCBES), National University of Ireland, Galway, Ireland.
| | | | | | - Terry J Smith
- Molecular Diagnostics Research Group, School of Natural Sciences, National Centre for Biomedical Engineering Science (NCBES), National University of Ireland, Galway, Ireland
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Development of internally controlled duplex real-time NASBA diagnostics assays for the detection of microorganisms associated with bacterial meningitis. J Microbiol Methods 2016; 127:197-202. [DOI: 10.1016/j.mimet.2016.06.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 11/22/2022]
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15
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Abstract
La synthèse des protéines, également appelée traduction, est assurée dans chaque cellule par des machines moléculaires très sophistiquées : les ribosomes. Compte tenu de l’immense quantité de données biologiques à traiter, il arrive régulièrement que ces machines se bloquent et mettent en péril la survie de la cellule. Chez les bactéries, le principal processus de sauvetage des ribosomes bloqués est la trans-traduction. Il est assuré par un acide ribonucléique (ARN) hybride, l’ARN transfert-messager (ARNtm), associé à une petite protéine basique, SmpB (small protein B). Plusieurs autres systèmes de contrôle qualité ont récemment été mis en évidence, révélant un réseau de maintien de la survie cellulaire très sophistiqué. Cette machinerie du contrôle qualité de la synthèse protéique est une cible très prometteuse pour le développement de futurs antibiotiques.
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Minogue E, Tuite NL, Smith CJ, Reddington K, Barry T. A rapid culture independent methodology to quantitatively detect and identify common human bacterial pathogens associated with contaminated high purity water. BMC Biotechnol 2015; 15:6. [PMID: 25888294 PMCID: PMC4342816 DOI: 10.1186/s12896-015-0124-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/06/2015] [Indexed: 02/06/2023] Open
Abstract
Background Water and High Purity Water (HPW) distribution systems can be contaminated with human pathogenic microorganisms. This biocontamination may pose a risk to human health as HPW is commonly used in the industrial, pharmaceutical and clinical sectors. Currently, routine microbiological testing of HPW is performed using slow and labour intensive traditional microbiological based techniques. There is a need to develop a rapid culture independent methodology to quantitatively detect and identify biocontamination associated with HPW. Results A novel internally controlled 5-plex real-time PCR Nucleic Acid Diagnostics assay (NAD), was designed and optimised in accordance with Minimum Information for Publication of Quantitative Real-Time PCR Experiments guidelines, to rapidly detect, identify and quantify the human pathogenic bacteria Stenotrophomonas maltophilia, Burkholderia species, Pseudomonas aeruginosa and Serratia marcescens which are commonly associated with the biocontamination of water and water distribution systems. The specificity of the 5-plex assay was tested against genomic DNA isolated from a panel of 95 microorganisms with no cross reactivity observed. The analytical sensitivities of the S. maltophilia, B. cepacia, P. aeruginosa and the S. marcescens assays are 8.5, 5.7, 3.2 and 7.4 genome equivalents respectively. Subsequently, an analysis of HPW supplied by a Millipore Elix 35 water purification unit performed using standard microbiological methods revealed high levels of naturally occurring microbiological contamination. Five litre water samples from this HPW delivery system were also filtered and genomic DNA was purified directly from these filters. These DNA samples were then tested using the developed multiplex real-time PCR NAD assay and despite the high background microbiological contamination observed, both S. maltophilia and Burkholderia species were quantitatively detected and identified. At both sampling points the levels of both S. maltophilia and Burkholderia species present was above the threshold of 10 cfu/100 ml recommended by both EU and US guidelines. Conclusions The novel culture independent methodology described in this study allows for rapid (<5 h), quantitative detection and identification of these four human pathogens from biocontaminated water and HPW distribution systems. We propose that the described NAD assay and associated methodology could be applied to routine testing of water and HPW distribution systems to assure microbiological safety and high water quality standards. Electronic supplementary material The online version of this article (doi:10.1186/s12896-015-0124-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elizabeth Minogue
- Nucleic Acid Diagnostics Research Laboratory (NADRL), Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Nina L Tuite
- Nucleic Acid Diagnostics Research Laboratory (NADRL), Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Cindy J Smith
- Marine Microbial Ecology Laboratory, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Kate Reddington
- Nucleic Acid Diagnostics Research Laboratory (NADRL), Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Thomas Barry
- Nucleic Acid Diagnostics Research Laboratory (NADRL), Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
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Konikkara KP, Baliga S, Shenoy S, Bharati B. Evaluation of Culture, Antigen Detection and Polymerase Chain Reaction for Detection of Vaginal Colonization of Group B Streptococcus (GBS) in Pregnant Women. J Clin Diagn Res 2014; 8:47-9. [PMID: 24701479 PMCID: PMC3972595 DOI: 10.7860/jcdr/2014/6675.4004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 12/24/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Group B Streptococcal infection is an important cause of neonatal morbidity and mortality. Early detection of perinatal vagino-rectal (VR) carriage of Group B Streptococcus (GBS) is important in the management of newborn infections. The objective of the study was to evaluate Culture, antigen detection and Polymerase chain reaction for detection of GBS in Pregnant women. SETTINGS AND DESIGN Observational descriptive study was done in a tertiary care hospital in Southern India. MATERIALS AND METHODS VR swabs were collected from 50 women at 35 to 37 weeks of gestation. Culture in a selective Lim enrichment broth with subsequent culture on 5% sheep blood agar, Conventional PCR assay and antigen detection method were performed. The performance of antigen detection and PCR methods were compared with culture. STATISTICAL ANALYSIS STATISTICAL ANALYSIS was performed by Chi-Square test. RESULTS GBS cultures were positive for 16% of the specimen (8 out of 50). Considering culture as a gold standard, Sensitivity, Specificity, Positive predictive value and Negative predictive value of antigen detection was 100%, 92.86%, 72.73%, 100% and similarly for that of PCR was 100%, 45.23%, 25.80%, 100%, respectively. CONCLUSION Antigen detection method was the rapid, sensitive and specific test for the detection of GBS colonizers during pregnancy.
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Affiliation(s)
- Kavitha Paul Konikkara
- Assistant Professor, Department of Microbiology, Government Medical College, Thrissur, India
| | - Shrikala Baliga
- Professor and Head, Department of Microbiology, Kasturba Medical College, Mangalore, India
| | - Suchithra Shenoy
- Associate Professor, Department of Microbiology, Kasturba Medical College, Mangalore, India
| | - B. Bharati
- Associate Professor, Department of Microbiology, Aua College of Medicine, Antigua, West Indies
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Carey AJ, Tan CK, Mirza S, Irving-Rodgers H, Webb RI, Lam A, Ulett GC. Infection and cellular defense dynamics in a novel 17β-estradiol murine model of chronic human group B streptococcus genital tract colonization reveal a role for hemolysin in persistence and neutrophil accumulation. THE JOURNAL OF IMMUNOLOGY 2014; 192:1718-31. [PMID: 24453257 DOI: 10.4049/jimmunol.1202811] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Genital tract carriage of group B streptococcus (GBS) is prevalent among adult women; however, the dynamics of chronic GBS genital tract carriage, including how GBS persists in this immunologically active host niche long term, are not well defined. To our knowledge, in this study, we report the first animal model of chronic GBS genital tract colonization using female mice synchronized into estrus by delivery of 17β-estradiol prior to intravaginal challenge with wild-type GBS 874391. Cervicovaginal swabs, which were used to measure bacterial persistence, showed that GBS colonized the vaginal mucosa of mice at high numbers (10(6)-10(7) CFU/swab) for at least 90 d. Cellular and histological analyses showed that chronic GBS colonization of the murine genital tract caused significant lymphocyte and PMN cell infiltrates, which were localized to the vaginal mucosal surface. Long-term colonization was independent of regular hormone cycling. Immunological analyses of 23 soluble proteins related to chemotaxis and inflammation showed that the host response to GBS in the genital tract comprised markers of innate immune activation including cytokines such as GM-CSF and TNF-α. A nonhemolytic isogenic mutant of GBS 874391, Δcyle9, was impaired for colonization and was associated with amplified local PMN responses. Induction of DNA neutrophil extracellular traps, which was observed in GBS-infected human PMNs in vitro in a hemolysin-dependent manner, appeared to be part of this response. Overall, this study defines key infection dynamics in a novel murine model of chronic GBS genital tract colonization and establishes previously unknown cellular and soluble defense responses to GBS in the female genital tract.
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Affiliation(s)
- Alison J Carey
- School of Medical Sciences, Griffith Health Institute, Griffith University, Gold Coast, Queensland 4222, Australia
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19
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Diagnostics method for the rapid quantitative detection and identification of low-level contamination of high-purity water with pathogenic bacteria. J Ind Microbiol Biotechnol 2013; 40:1005-13. [PMID: 23783648 DOI: 10.1007/s10295-013-1295-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
Abstract
High-purity water (HPW) can be contaminated with pathogenic microorganisms, which may result in human infection. Current culture-based techniques for the detection of microorganisms from HPW can be slow and laborious. The aim of this study was to develop a rapid method for the quantitative detection and identification of pathogenic bacteria causing low-level contamination of HPW. A novel internally controlled multiplex real-time PCR diagnostics assay was designed and optimized to specifically detect and identify Pseudomonas aeruginosa and the Burkholderia genus. Sterile HPW, spiked with a bacterial load ranging from 10 to 10(3) cfu/100 ml, was filtered and the bacterial cells were removed from the filters by sonication. Total genomic DNA was then purified from these bacteria and subjected to testing with the developed novel multiplex real-time PCR diagnostics assay. The specific P. aeruginosa and Burkholderia genus assays have an analytical sensitivity of 3.5 genome equivalents (GE) and 3.7 GE, respectively. This analysis demonstrated that it was possible to detect a spiked bacterial load of 1.06 × 10(2) cfu/100 ml for P. aeruginosa and 2.66 × 10(2) cfu/100 ml for B. cepacia from a 200-ml filtered HPW sample. The rapid diagnostics method described can reliably detect, identify, and quantify low-level contamination of HPW with P. aeruginosa and the Burkholderia genus in <4 h. We propose that this rapid diagnostics method could be applied to the pharmaceutical and clinical sectors to assure the safety and quality of HPW, medical devices, and patient-care equipment.
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Poncelet-Jasserand E, Forges F, Varlet MN, Chauleur C, Seffert P, Siani C, Pozzetto B, Ros A. Reduction of the use of antimicrobial drugs following the rapid detection ofStreptococcus agalactiaein the vagina at delivery by real-time PCR assay. BJOG 2013; 120:1098-108. [DOI: 10.1111/1471-0528.12138] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2012] [Indexed: 11/29/2022]
Affiliation(s)
- E Poncelet-Jasserand
- Department of Obstetrics; Gynaecology and Reproductive Medicine; University-Hospital of Saint-Etienne; France
| | - F Forges
- Unit of Clinical Research, Innovation and Pharmacology; INSERM CIE3; University-Hospital of Saint-Etienne; France
| | - M-N Varlet
- Department of Obstetrics; Gynaecology and Reproductive Medicine; University-Hospital of Saint-Etienne; France
| | - C Chauleur
- Department of Obstetrics; Gynaecology and Reproductive Medicine; University-Hospital of Saint-Etienne; France
| | - P Seffert
- Department of Obstetrics; Gynaecology and Reproductive Medicine; University-Hospital of Saint-Etienne; France
| | - C Siani
- Research Laboratory in Knowledge Engineering (ERIC); University of Lyon; Institute of Pharmaceutical and Biological Sciences (ISPB) of Lyon; France
| | | | - A Ros
- Department of Microbiology; Hôpital Nord; University-Hospital of Saint-Etienne; France
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21
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Abstract
In recent years, quantitative real-time PCR tests have been extensively developed in clinical microbiology laboratories for routine diagnosis of infectious diseases, particularly bacterial diseases. This molecular tool is well-suited for the rapid detection of bacteria directly in clinical specimens, allowing early, sensitive and specific laboratory confirmation of related diseases. It is particularly suitable for the diagnosis of infections caused by fastidious growth species, and the number of these pathogens has increased recently. This method also allows a rapid assessment of the presence of antibiotic resistance genes or gene mutations. Although this genetic approach is not always predictive of phenotypic resistances, in specific situations it may help to optimize the therapeutic management of patients. Finally, an approach combining the detection of pathogens, their mechanisms of antibiotic resistance, their virulence factors and bacterial load in clinical samples could lead to profound changes in the care of these infected patients.
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Affiliation(s)
- Max Maurin
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et Pathologie, CHU de Grenoble, Université Joseph Fourier Grenoble 1, France.
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Berg BR, Houseman JL, Garrasi MA, Young CL, Newton DW. Culture-based method with performance comparable to that of PCR-based methods for detection of group B Streptococcus in screening samples from pregnant women. J Clin Microbiol 2013; 51:1253-5. [PMID: 23345288 PMCID: PMC3666823 DOI: 10.1128/jcm.02780-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/12/2013] [Indexed: 11/20/2022] Open
Abstract
We compared five approaches for group B streptococcus (GBS) detection: three culture-based methods and two methods using broth-enhanced real-time PCR. Carrot broth-enhanced subculture to GBS Detect (Hardy Diagnostics, Santa Maria, CA) exhibited sensitivity and specificity comparable to carrot broth- and LIM broth-enhanced real-time PCRs.
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Affiliation(s)
- Benjamin R Berg
- Department of Pathology, University of Michigan Health System, Ann Arbor, Michigan, USA
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23
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de Zoysa A, Edwards K, Gharbia S, Underwood A, Charlett A, Efstratiou A. Non-culture detection of Streptococcus agalactiae (Lancefield group B Streptococcus) in clinical samples by real-time PCR. J Med Microbiol 2012; 61:1086-1090. [PMID: 22740612 DOI: 10.1099/jmm.0.042879-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A real-time PCR assay targeting the cylB gene was developed to detect Streptococcus agalactiae [Lancefield group B Streptococcus (GBS)] from clinical samples. A total of 110 blood culture-negative samples [75 cerebrospinal fluid (CSF) and 35 EDTA blood samples] from neonates with probable GBS sepsis or meningitis were analysed. Among these, 16 of the 75 CSF samples were positive [21.3%, 95% confidence interval (CI) 12.7-32.3%] and two of the 35 EDTA blood samples were positive (5.7%, 95% CI 0.7-19.2%). The proportion testing positive in the CSF samples was significantly higher than in the EDTA blood samples (P=0.05, Fisher's exact test). Overall, this real-time PCR assay was shown to be superior to culture methods for detection of GBS from CSF and EDTA blood samples.
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Affiliation(s)
- Aruni de Zoysa
- Respiratory and Systemic Infection Laboratory, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
| | - Kirstin Edwards
- Department of Bioanalysis and Horizon Technologies, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
| | - Saheer Gharbia
- Department of Bioanalysis and Horizon Technologies, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
| | - Anthony Underwood
- Applied Bioinformatics Laboratory & Epidemiology, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
| | - André Charlett
- Statistics, Modelling and Economics Department, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
| | - Androulla Efstratiou
- Respiratory and Systemic Infection Laboratory, Health Protection Agency, Microbiology Services Division, Colindale, London, UK
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Clancy E, Glynn B, Reddington K, Smith T, Barry T. Culture confirmation of Listeria monocytogenes using tmRNA as a diagnostics target. J Microbiol Methods 2012; 88:427-9. [DOI: 10.1016/j.mimet.2011.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 12/22/2011] [Accepted: 12/22/2011] [Indexed: 11/29/2022]
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El Aila NA, Tency I, Claeys G, Verstraelen H, Deschaght P, Decat E, Lopes dos Santos Santiago G, Cools P, Temmerman M, Vaneechoutte M. Comparison of culture with two different qPCR assays for detection of rectovaginal carriage of Streptococcus agalactiae (group B streptococci) in pregnant women. Res Microbiol 2011; 162:499-505. [DOI: 10.1016/j.resmic.2011.04.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/11/2011] [Indexed: 11/28/2022]
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26
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O'Connor L, Glynn B. Recent advances in the development of nucleic acid diagnostics. Expert Rev Med Devices 2010; 7:529-39. [PMID: 20583889 DOI: 10.1586/erd.10.22] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Since the early 1970s, the use of nucleic acid sequences for specific diagnostic applications has followed a somewhat linear pattern of development. Early methods for restriction enzyme digestion, as well as reverse transcription, were followed in the late 1970s by Southern, northern and dot blotting, as well as DNA sequencing. In 1985, the description of PCR and the routine laboratory manipulation of sufficient quantities of DNA for diagnostics, resulted in the exponential growth of molecular biology. Subsequently, alternative DNA and RNA amplification protocols followed. The last 10 years have seen the second explosion in molecular biology with the development of real-time quantitative PCR and oligonucleotide microarrays. This advancement continues with the development of methods for 'direct' nucleic acid target detection from samples without in vitro amplification, and enhanced transduction elements for improved sensitivity of nucleic acid detection. In this article, we will describe the current state of the art in nucleic acid diagnostics, the use of nucleic acid-based diagnostics in clinical practice and the emerging technologies in the field. Finally, we will describe future trends and expected advances in the field.
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Multicenter evaluation of the BD Max GBS assay for detection of group B streptococci in prenatal vaginal and rectal screening swab specimens from pregnant women. J Clin Microbiol 2010; 48:4239-41. [PMID: 20826650 DOI: 10.1128/jcm.00947-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new integrated extraction and real-time PCR-based system for the detection of group B streptococci in antepartum screening samples enriched in Lim broth was compared to the CDC-recommended culture method. The BD Max GBS assay exhibited acceptable sensitivity (95%) and specificity (96.7%) compared to those of the culture method in this multisite evaluation.
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28
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Real-time PCR assay provides reliable assessment of intrapartum carriage of group B Streptococcus. J Clin Microbiol 2010; 48:3095-9. [PMID: 20592137 DOI: 10.1128/jcm.00594-10] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The objective of this study was to determine the reliability of the real-time PCR assay for determining the group B Streptococcus (GBS) status of women in labor. In this prospective study we compared the results of culture and PCR testing of vaginal and rectal samples collected by nursing staff when women were in labor. Patients' charts were also reviewed to obtain relevant information about pregnancy risk factors. Our results demonstrated a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 90.5%, 96.1%, 86.4%, and 97.4%, respectively, for rapid PCR. Of the 196 women evaluated, 29 (14.8%) presented with unknown GBS status, 11 (37.9%) of whom received unnecessary intrapartum antibiotics. The rapid real-time PCR test was robust and was able to reliably detect the presence of GBS in women in labor within 1 h of specimen submission to the laboratory. We recommend that the rapid PCR test be targeted to women who present in labor with unknown GBS status. In cases where the laboratory does not offer 24-h availability of testing, sample collection followed by PCR testing the next morning is still valuable and provides reliable results 24 to 48 h faster than culture and will aid appropriate decision-making regarding continuing or stopping antibiotics for neonates of women with unknown GBS status.
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O'Grady J, Lacey K, Glynn B, Smith TJ, Barry T, Maher M. tmRNA--a novel high-copy-number RNA diagnostic target--its application for Staphylococcus aureus detection using real-time NASBA. FEMS Microbiol Lett 2009; 301:218-23. [PMID: 19889030 DOI: 10.1111/j.1574-6968.2009.01822.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A real-time nucleic acid sequence-based amplification assay, targeting tmRNA, was designed for the rapid identification of Staphylococcus aureus. The selectivity of the assay was confirmed against a panel of 76 Staphylococcus strains and species and 22 other bacterial species. A detection limit of 1 cell equivalent was determined for the assay. A chimeric in vitro transcribed internal amplification control was developed and included in the assay. Application of the assay in natural and artificially contaminated unpasteurized (raw) milk enabled detection of 1-10 CFUS. aureus mL(-1) in 3-4 h, without the need for culture enrichment. Staphylococcus aureus was detected in all artificially contaminated milk samples (n=20) and none of the natural milk samples (n=20). Microbiological analysis of the natural milk samples was performed in parallel according to ISO 6888-3 and confirmed the absence of S. aureus. The method developed in this study has the potential to enable the specific detection of S. aureus in raw milk in a significantly shorter time frame than current standard methods. The assay further demonstrates the usefulness of tmRNA/ssrA as a nucleic acid diagnostic target.
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Affiliation(s)
- Justin O'Grady
- The Biomedical Diagnostics Institute Program, National University of Ireland Galway, Galway, Ireland.
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