Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women: Sensitivity, specificity and predictive values

Background. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 - 72 hours). Rapid assays are required to determine maternal carriage of GBS.Objectives. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women.Methods. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method.Results. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%.Conclusions. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every labour ward, where women can be screened for GBS on arrival

Antimicrobial susceptibility and serotype distribution of Streptococcus agalactiae rectovaginal colonising isolates from pregnant women at a tertiary hospital in Pretoria, South Africa: An observational descriptive study

Background. Streptococcus agalactiae or group B streptococcus (GBS) is a significant cause of neonatal sepsis. Intrapartum antibiotic prophylaxis is recommended for pregnant women identified to be rectovaginally colonised between 34 and 37 weeks’ gestational age to decrease the risk of invasive disease in their newborns. An effective multivalent GBS vaccine may prevent a broader scope of GBS-associated diseases, such as GBS early-onset disease, GBS late-onset disease, spontaneous abortion, stillbirth and maternal bacteraemia. Serotype distribution of GBS isolates is essential to determine the efficacy of such a vaccine.Objectives. To investigate serotype distribution and antimicrobial susceptibility patterns of GBS isolates cultured from rectovaginal specimens during pregnancy.Methods. Sixty-nine archived maternal colonising isolates were tested against penicillin, erythromycin, clindamycin, vancomycin and levofloxacin. Minimum inhibitory concentration testing was performed using the ETEST method. Serotyping was performed by the latex agglutination method.Results. The most common serotypes detected were Ia (54%), III (20%), V (16%), II (6%), IV (2%) and Ib (1%). All isolates were fully susceptible to penicillin, vancomycin and levofloxacin. Eight (11%) and 50 (56%) isolates showed intermediate resistance to erythromycin and clindamycin, respectively, and 1 isolate was resistant to erythromycin. The macrolide-lincosamide-streptogramin B (MLSB) phenomenon was noted in 3 (4%) of the isolates.Conclusions. GBS-colonising isolates remain susceptible to penicillin, which remains the drug of choice for intrapartum antibiotic prophylaxis and treatment of invasive disease in newborns. Macrolides should only be used if clinically indicated due to the high prevalence of intermediate resistance. A pentavalent GBS vaccine currently in phase I trials should provide coverage for 97% of the isolates identified in this study

Comparison of Xpert GBS v. culture for rapid detection of group B streptococcus in pregnant women: Sensitivity, specificity and predictive values

Background. Group B streptococcus (GBS) is a leading cause of invasive disease, particularly in newborns. Seventy-five percent of neonates will be colonised by mothers carrying the organism. Confirmation of maternal colonisation with GBS is essential for prompt treatment and prevention of neonatal sepsis. The current gold standard of culture for isolation of GBS has a disadvantage of long turnaround time (24 - 72 hours). Rapid assays are required to determine maternal carriage of GBS.Objectives. To determine the usefulness of the Xpert GBS technology v. culture methods to detect GBS carriage in pregnant women.Methods. This was a prospective observational study of 284 pregnant women between 26 and 37 weeks’ gestation. Two vaginorectal swabs were collected from each participant. One swab was processed using the gold-standard culture method, while the second swab was processed using the Xpert GBS assay. The performance of the Xpert GBS assay was then compared with that of the culture method.Results. Two swabs were processed from each of 284 pregnant women between 26 and 37 weeks’ gestation. Culture detected 70 GBS isolates from a total of 279 specimens (25.1%), whereas the Xpert GBS detected 66 positive specimens (23.7%). The Xpert GBS assay had a sensitivity of 87% and specificity of 98%, with a positive predictive value of 92% and a negative predictive value of 96%.Conclusions. The Xpert GBS assay is a rapid and sensitive tool for prenatal detection of GBS. The assay should ideally be available in every labour ward, where women can be screened for GBS on arrival.

Meningococcal infections in hospitalised patients in Pretoria

We report on 13 patients diagnosed with meningococcal infections in patients attending state-owned hospitals serving an indigent population in Pretoria in 2009. The case fatality rate was 27%. Ceftriaxone was the main antibiotic (9 out of 13 patients) for therapy. Five isolates (39%) were serogroup B and 4 (31%) serogroup W135. Most isolates (12/13) were fully susceptible to penicillin (MIC range 0.016 - 0.047 g/ml). A single isolate was intermediately resistant to penicillin (MIC, 0.125 g/ml) while all isolates were uniformly susceptible to ceftriaxone, ciprofloxacin and rifampicin. This pattern reveals a shift in serogroups with an increase of serogroup B disease in the Pretoria region, and the need for ongoing monitoring of antimicrobial susceptibility profiles and the value of ceftriaxone for favourable therapeutic outcome

Epidemiology of invasive group B streptococcal disease in infants from urban area of South China, 2011–2014

YesBackground: Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in infants in both developed and developing countries. To our knowledge, only a few studies have been reported the clinical features, treatment and outcomes of the GBS disease in China. The severity of neonatal GBS disease in China remains unclear. Population-based surveillance in China is therefore required. Methods: We retrospectively collected data of <3 months old infants with culture-positive GBS in sterile samples from three large urban tertiary hospitals in South China from Jan 2011 to Dec 2014. The GBS isolates and their antibiotic susceptibility were routinely identified in clinical laboratories in participating hospitals. Serotyping and multi-locus sequence typing (MLST) were also conducted for further analysis of the neonatal GBS disease. Results: Total 70 cases of culture-confirmed invasive GBS infection were identified from 127,206 live births born in studying hospitals, giving an overall incidence of 0.55 per 1000 live births (95% confidence interval [CI] 0.44–0.69). They consisted of 49 with early-onset disease (EOD, 0.39 per 1000 live births (95% CI 0.29–0.51)) and 21 with late-onset disease (LOD, 0.17 per 1000 live births (95% CI 0.11–0.25)). The incidence of EOD increased significantly over the studying period. Five infants (4 EOD and 1 LOD) died before discharge giving a mortality rate of 7.1% and five infants (7.1%, 2 EOD and 3 LOD) had neurological sequelae. Within 68 GBS isolates from GBS cases who born in the studying hospitals or elsewhere, serotype III accounted for 77.9%, followed by Ib (14.7%), V (4.4%), and Ia (2.9%). MLST analysis revealed the presence of 13 different sequence types among the 68 GBS isolates and ST-17 was the most frequent sequence type (63.2%). All isolates were susceptible to penicillin, ceftriaxone, vancomycin and linezolid, while 57.4% and 51.5% were resistant to erythromycin and clindamycin, respectively. Conclusions: This study gains the insight into the spectrum of GBS infection in south China which will facilitate the development of the guidance for reasonable antibiotics usage and will provide evidence for the implementation of potential GBS vaccines in the future.Supported by medical and health science and technology projects of Health and Family Planning Commission of Guangzhou Municipality (grant number 20151A010034) and Guangdong provincial science and technology planning projects (grant number 2014A020212520)

Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries.

Globally, group B Streptococcus (GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation. This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations

Vaccine value profile for Klebsiella pneumoniae

Klebsiella pneumoniae causes community- and healthcare-associated infections in children and adults. Globally in 2019, an estimated 1.27 million (95% Uncertainty Interval [UI]: 0.91–1.71) and 4.95 million (95% UI: 3.62–6.57) deaths were attributed to and associated with bacterial antimicrobial resistance (AMR), respectively. K. pneumoniae was the second leading pathogen in deaths attributed to AMR resistant bacteria. Furthermore, the rise of antimicrobial resistance in both community- and hospital-acquired infections is a concern for neonates and infants who are at high risk for invasive bacterial disease. There is a limited antibiotic pipeline for new antibiotics to treat multidrug resistant infections, and vaccines targeted against K. pneumoniae are considered to be of priority by the World Health Organization. Vaccination of pregnant women against K. pneumoniae could reduce the risk of invasive K. pneumoniae disease in their young offspring. In addition, vulnerable children, adolescents and adult populations at risk of K. pneumoniae disease with underlying diseases such as immunosuppression from underlying hematologic malignancy, chemotherapy, patients undergoing abdominal and/or urinary surgical procedures, or prolonged intensive care management are also potential target groups for a K. pneumoniae vaccine. A ‘Vaccine Value Profile’ (VVP) for K. pneumoniae, which contemplates vaccination of pregnant women to protect their babies from birth through to at least three months of age and other high-risk populations, provides a high-level, holistic assessment of the available information to inform the potential public health, economic and societal value of a pipeline of K. pneumoniae vaccines and other preventatives and therapeutics. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public–private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the WHO. All contributors have extensive expertise on various elements of the K. pneumoniae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information