scholarly journals False-positive detection of Group B Streptococcus (GBS) in chromogenic media due to presence of Enterococcus faecalis in High Vaginal Swabs

2021 ◽  
Author(s):  
Abhishek Singh ◽  
Atahar Husein ◽  
Salomi Singh ◽  
vikas ghattargi ◽  
Dhiraj dhotre ◽  
...  
Keyword(s):  
16S Rrna ◽  
Enterococcus Faecalis ◽  
Group B Streptococcus ◽  
Vaginal Swab ◽  
Blood Agar ◽  
Specific Pcr ◽  
False Positive Detection ◽  
Vaginal Swabs ◽  
Rrna Sequencing ◽  
Group B

Background Group B Streptococcus (GBS) is a gram-positive bacterium and its vaginal colonization is associated with preterm births and neonatal sepsis. Thus, routine screening of GBS in prenatal care before the onset of labour is recommended. Recently chromogenic media have been develop and are found to be useful in rapid and sensitive screening for GBS in vaginal swabs. In the present study we evaluated the performance of chromogenic media for the detection of GBS in vaginal swabs of pregnant Indian women near term. Methodology In this study 201 vaginal swab samples were collected from pregnant women. Swabs were inoculated in chromogenic media (carrot broth).The positive and negative cultures were inoculated on Blood agar and Crome agar plates. The colonies were subjected to 16S rRNA sequencing and gene-specific PCR for confirmation. CAMP and BEA were used for biochemical confirmation. PCR was done on genomic DNA isolated from uncultured vaginal swabs. Result 20/201(9.9%) vaginal swab samples were positive in the carrot broth. 17/20 (85%) and 19/20 (95%) of these samples yielded colonies on Blood agar and Crome agar respectively. Of the 181 carrot broth negative samples 1(0.5%) and 38 (20.9%) yielded colonies on Blood agar and crome agar plates respectively. However 16s rRNA sequencing revealed that none of the 20 carrot broth positive cultures were that of GBS and had sequence similarities to the Enterococcus faecalis. This was also confirmed by using gene specific PCR and BEA positivity. Furthermore, Enterococcus faecalis was detected by PCR in DNA isolated from 57 uncultured vaginal swabs samples, GBS could be detected by PCR only in 4 samples. Conclusion Carrot Broth-based culture can lead to false-positive detection due to the presence of Enterococcus faecalis. Keywords: Streptococcus agalactiae, Infection, PCR, pregnant women, Carrot Broth, Blood agar, Crome agar, Preterm birth, Sepsis

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

2013 ◽  
Vol 5 (01) ◽  
pp. 42-45 ◽  
Author(s):  
Kavitha P Konikkara ◽  
Shrikala Baliga ◽  
Suchitra M Shenoy ◽  
B Bharati
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Culture Method ◽  
Sheep Blood Agar ◽  
Blood Agar ◽  
Third Trimester ◽  
Sheep Blood ◽  
Vaginal Colonization ◽  
Vaginal Swabs ◽  
Group B

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

scholarly journals Prevalence and antibiotic sensitivity of Group B Streptococcus (GBS) infection among antenatal women

2018 ◽  
Vol 7 (5) ◽  
pp. 1768
Author(s):  
Nishita Shettian ◽  
Shetty Theertha Shankar ◽  
Manjunath Kamath Ammembal
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Antibiotic Sensitivity ◽  
Neonatal Morbidity ◽  
Vaginal Swab ◽  
Drug Of Choice ◽  
Nasal Swabs ◽  
Vaginal Swabs ◽  
Life Threatening ◽  
Group B

Background: Group B Streptococcus (GBS) infection in pregnant women is a major concern as it causes septicemia in neonates which is fatal and potentially life threatening. Objectives of present study were to study the distribution of Group B streptococcus infection among pregnant women at term, to understand if penicillin is still effective as the drug of choice, to determine the alternate drug of choice in women with Group B streptococcus infection if resistant to penicillin and analyze the proportion of Group B Streptococcus infection as a vaginal commensal.Methods: This is a hospital based prospective study comprising of 350 pregnant women at term gestation. Vaginal swabs as well as neonatal nasal swabs following delivery were collected under aseptic precautions and sent for culture and sensitivity.Results: Vaginal swab culture reports of 308 women out of 350 showed a growth. Candida albicans (23.8%), Enterococcus (5.6%), Escherichia coli (4.2%), MRSA (4.2%), Staphylococcus aureus (1.4%) and Group B Streptococcus (1.4%) were the organisms isolated. Penicillin is still the drug of choice for group B Streptococcal infection in antenatal women with Linezolid being the alternate drug of choice. None of the neonatal nasal swabs revealed any growth on culture and sensitivity.Conclusions: This study does not recommend routine screening for Group B Streptococcus in all pregnant women unless they have a positive history in previous pregnancies. Our study also revealed various other organisms which could be responsible for increasing the risk of maternal and neonatal morbidity.

Prevalence and capsular type distribution of group B Streptococcus isolated from vagina of pregnant women in Nghe An province, Vietnam

2020 ◽  
Author(s):  
Tran Quang Hanh ◽  
Vu Van Du ◽  
Pham Thu Hien ◽  
Duong Dinh Chinh ◽  
Cao Ba Loi ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Specific Pcr ◽  
Gram Staining ◽  
Central Vietnam ◽  
Vaginal Swabs ◽  
The World ◽  
Viii And Ix ◽  
Camp Test ◽  
Group B

Background and Objectives: Identification of GBS serotypes provides helpful information for appropriate the develop- ment of suitable vaccines; however, no reports from Vietnam have been published. This study has been performed to find the prevalence and serotypes of group B Streptococcus isolated from vagina of pregnant women in Nghe An province, Vietnam. Materials and Methods: Vaginal swabs were collected from pregnant women at 35-37 weeks of gestation at the Nghe An Obstetrics and Pediatrics Hospital, Vietnam between May 2018 and July 2019. The swabs were cultured on 5% sheep blood agar for isolation of GBS. All isolates were identified using the Gram staining, CAMP test and specific PCR. GBS strains were serotyped using the multiplex PCR assays. Results: The prevalence of vaginal GBS colonization was 9.20% of 750 participants. Among the isolates, serotypes III (39.13%) and V (31.89%) were the most frequent, followed by serotypes Ia (11.59%), VI (11.59%), Ib (2.90%), II (1.45%) and VII (1.45%), respectively. Serotypes IV, VIII and IX were not found. Conclusion: The prevalence of GBS in the Nghe An province of central Vietnam was similar to reports from other parts of the world. The predominat GBS serotypes (III, V, Ia and VI) were slightly different from those previously described from other regions around the world. The high frequency of serotype VI was a notable feature of the strains from pregnant women in Vietnam.

scholarly journals Performance of PhenoMatrix for the detection of Group B Streptococcus from recto-vaginal swabs

2021 ◽  
pp. 115427
Author(s):  
Claudio Foschi ◽  
Gabriele Turello ◽  
Tiziana Lazzarotto ◽  
Simone Ambretti
Keyword(s):  
Group B Streptococcus ◽  
Vaginal Swabs ◽  
Group B

scholarly journals Genital tract group B streptococcal colonization in pregnant women: a South Indian perspective

2011 ◽  
Vol 5 (08) ◽  
pp. 592-595 ◽  
Author(s):  
Vijayan Sharmila ◽  
Noyal Mariya Joseph ◽  
Thirunavukkarasu Arun Babu ◽  
Latha Chaturvedula ◽  
Sujatha Sistla
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Colonization Rate ◽  
Antibiotic Susceptibility Pattern ◽  
South Indian ◽  
Vaginal Swabs ◽  
Rectal Swabs ◽  
Resistance To Penicillin ◽  
Group B ◽  
A Prospective Study

Introduction: During the last few decades, group B Streptococcus (GBS) has emerged as an important pathogen. The major reservoirs for GBS are the vagina and the peri-anal regions/rectum, and the colonization of these regions is a risk factor for subsequent infection in pregnant women and newborns. Methodology: A prospective study was performed to determine the prevalence of GBS colonization in the vagina and rectum of pregnant women and the antibiotic susceptibility pattern of the isolates. We also aimed to identify risk factors associated with GBS colonization. The vaginal and rectal swabs were inoculated in Todd-Hewitt broth and later subcultured on blood agar for isolation of GBS. Results: A total of 300 pregnant women were enrolled in the study. GBS strains were isolated from seven out of 300 patients, corresponding to a colonization rate of 2.3%. Of the seven patients carrying GBS, isolates were cultured only from vaginal swabs in two cases (28.6%), only from rectal swabs in two cases (28.6%) from both vaginal and rectal swabs in three cases (42.9%). Heavy colonization was present only in 42.9% (3/7) of antenatal women. None of the seven isolates were resistant to penicillin or clindamycin, while one isolate (14.3%) was resistant to erythromycin and five isolates (71.4%) were resistant to tetracycline. Multigravid women and those with previous spontaneous abortion were more frequently colonized by GBS. Conclusion: The GBS colonization rate in our study was low. No resistance to penicillin or clindamycin was seen, while the majority of the isolates were resistant to tetracycline.

scholarly journals Prevalence and Serotype Determination of Streptococcus agalactiae Isolated From Non-Pregnant Women in Tehran, Iran

2020 ◽  
Author(s):  
Leila Goudarzi ◽  
Mohammad Bagher Khalili ◽  
Mahmood Vakili ◽  
Maryam Sadeh
Keyword(s):  
Pregnant Women ◽  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Cross Sectional Study ◽  
Chi Square ◽  
Cross Sectional ◽  
Specific Pcr ◽  
Pcr Method ◽  
Group B ◽  
Tehran Area

Consequence of Streptococcus agalactiae, Group B Streptococcus (GBS) relating infant’s diseases are well documented. Although many women carry this bacterium in their vagina, they may transfer to their infant during delivery and may result in different neonatal invasive diseases. The aim of this study was to determine the prevalence of GBS and serotyping the isolated species among un-selective non-pregnant women who attended two gynecology clinics in Tehran. In this cross-sectional study, a total of 560 vaginal samples collected from non-pregnant women. Following inoculation of the specimen on Blood Agar, the standard technology was applied for the final identification of GBS. Detected GBS species were further confirmed using specific PCR directed on dlts gene. Capsular serotyping was done by using the multiplex PCR method. The chi-square method was used for statistical analysis. Fifty (8.9%) out of 560 non-pregnant women were carriers of GBS. The most common types were III (36%), followed by type II (32%), Ia (26%), and Ib (6%), respectively. Results represent that the prevalence rate of GBS in non-pregnant women was reliable and similar to what obtained from pregnant women. In addition, the serotype III was found the most dominant types, as well as other investigations in the Tehran area. Therefore, vaccine designation based on type III is recommended.

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

2021 ◽  
Vol 11 ◽  
Author(s):  
Kankan Gao ◽  
Qiulian Deng ◽  
Lianfen Huang ◽  
Chien-Yi Chang ◽  
Huamin Zhong ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Agar Plate ◽  
Reference Method ◽  
Antigen Detection ◽  
The Other ◽  
Blood Agar ◽  
Blood Agar Plate ◽  
Chromogenic Agar ◽  
Group B ◽  
Detection Reagent

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

scholarly journals Group B streptococcus colonisation in pregnant women at Dr. George Mukhari Hospital, South Africa

2016 ◽  
Vol 31 (3) ◽  
pp. 74-78
Author(s):  
M. C. Monyama ◽  
J. Y. Bolukaoto ◽  
M. O. Chukwu ◽  
M. R.B. Maloba ◽  
S. R. Moyo ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Age Groups ◽  
Agar Plate ◽  
Broth Culture ◽  
Culture Methods ◽  
Enrichment Broth ◽  
Colonisation Rate ◽  
Vaginal Swabs ◽  
Group B

The aim of the study was to estimate group B streptococcus (GBS) colonisation in pregnant mothers using selective enrichment broth and solid media for culturing GBS. Vaginal and rectal swabs were collected from 413 pregnant women for GBS culture at recruitment stage. Direct plating and enrichment broth culture methods were compared by using the same swab samples. The swabs were cultured on colistin nalidixic agar (CNA) plate and incubated at 37°C and examined after 18-24 h. The samples which were culture negative on a CNA agar plate were then inoculated into a Todd-Hewitt enrichment broth to recover any GBS present that was not recovered on the solid agar. With the CNA agar plate, the samples were cultured separately to enable identification of colonised sites such as vaginal sites or rectal sites. Rectal and vaginal swabs were inoculated into Todd-Hewitt enrichment broth at the same time in the same tube. The GBS colonisation rate in pregnant women was 30.9% (128/413). The CNA agar plate recovered 45.3% (58/128) of the GBS isolates, whereas 54.7% (70/128) isolates were recovered from Todd-Hewitt broth. Pregnant women of various ages were found to be at risk of GBS colonisation. The colonisation rate was however highest among women of 25–29 age groups as compared with other age groups. Detection of group B streptococcus improved when both rectal and vaginal swabs were collected for laboratory analysis. The simultaneous use of Todd-Hewitt broth and CNA plate also improved the yield of group B streptococcus.

Prevalence and Factors Associated with Maternal Group B Streptococcus Colonization in Madagascar and Senegal

2021 ◽  
Author(s):  
Yu-Jin Jung ◽  
Bich-Tram Huynh ◽  
Abdoulaye Seck ◽  
Raymond Bercion ◽  
Fatoumata Diene Sarr ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Group B Streptococcus ◽  
Sociodemographic Characteristics ◽  
Community Based ◽  
Middle Income ◽  
Factors Associated ◽  
Middle Income Countries ◽  
Sociodemographic Data ◽  
Vaginal Swabs ◽  
Group B

Maternal group B Streptococcus (GBS) colonization is a major risk factor for neonatal GBS infection. However, data on GBS are scarce in low- and middle-income countries. Using sociodemographic data and vaginal swabs collected from an international cohort of mothers and newborns, this study aimed to estimate the prevalence of GBS colonization among pregnant women in Madagascar ( n = 1,603) and Senegal ( n = 616). The prevalence was 5.0% (95% CI, 3.9–6.1) and 16.1% (95% CI, 13.1–19.0) in Madagascar and Senegal, respectively. No factors among sociodemographic characteristics, living conditions, and obstetric history were found to be associated independently with GBS colonization in both countries. This community-based study provides one of the first estimates of maternal GBS colonization among pregnant women from Madagascar and Senegal.

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