Interactions between Streptococcus agalactiae and Candida albicans affect persistence and virulence.

Group B Streptococcus (GBS) is a species of gram positive bacteria representing a significant human pathogen; namely, as the most prolific cause of neonatal disease and mortality globally, but also increasingly reported in adult disease (especially among the elderly and those with compromised immune systems). The first chapter of this thesis reviews the extensive literature covering GBS; with a focus on classification and disease. Selected virulence factors are also discussed. In chapter 2, eight strains of GBS were selected for whole genome sequencing by Third Generation, Pacific Biosystems (PacBio) sequencing technology. A protocol was optimised to provide sufficient, high quality genomic preparations from multiple strains of GBS – suitable for the PacBio technology. Using a sequenced strain of GBS from chapter 2, an infection model was optimised in chapter 3 for the purpose of providing quality RNA for co-transcript analysis. U937 human monocytes were infected with GBS (strain 874391) and the host/pathogen RNA prepared from the same reaction (monocytes with internalised GBS) – with an emphasis on yielding sufficient pathogen RNA; which can sometime be an impediment for co-transcript studies. Pathogen RNA derived from the optimised infection protocol was demonstrated to amplify with RT-qPCR for 12 tested GBS genes (cylE, 1010, rib, czcD, pil2B, cpsE, scpB, htp, cfb, copA, hvgA and maeA). In chapter 4, RT-qPCR was used to analyse differential gene expression from the mixed, host/pathogen RNA. Twelve human genes and 12 GBS genes were assessed for differential gene expression. Seven of the tested human genes (IL8, IL1A, IL1B, IL10, TNF, LMO2 and MCP-1) and 6 of the tested GBS genes (scpB, 1010, rib, czcD, htp, hvgA) were significantly upregulated in RNA derived from the infection samples. Of the GBS genes tested, htp was the most upregulated. An htp knockout mutant of GBS strain 874391 (Δhtp) was constructed for chapter 5 of this thesis to assess the impact of htp transcription on GBS survival in an infection context. The infection assays optimised in chapter 3 were performed with the Δhtp GBS construct. Contrary to expectation, the Δhtp GBS construct survived the internalised environment of the monocytes in significantly higher numbers than the wild-type over 48 hours of infection.

Group B Streptococcus (GBS) is an opportunistic pathogen that causes preterm birth and neonatal disease. Although GBS is known to exhibit vast diversity in virulence across strains, the mechanisms of GBS-associated pathogenesis are incompletely understood. We hypothesized that GBS strains of different genotypes would vary in their ability to elicit host inflammatory responses, and that strains associated with neonatal disease would induce different cytokine profiles than those associated with colonization. Using a multiplexed, antibody-based protein detection array, we found that production of a discrete number of inflammatory mediators by THP-1 macrophage-like cells was universally induced in response to challenge with each of five genetically distinct GBS isolates, while other responses appeared to be strain-specific. Key array responses were validated by ELISA using the initial five strains as well as ten additional strains with distinct genotypic and phenotypic characteristics. Interestingly, IL-6 was significantly elevated following infection with neonatal infection-associated sequence type (ST)-17 strains and among strains possessing capsule (cps) type III. Significant differences in production of IL1-β, IL-10 and MCP-2 were also identified across STs and cps types. These data support our hypothesis and suggest that unique host innate immune responses reflect strain-specific differences in virulence across GBS isolates. Such data might inform the development of improved diagnostic or prognostic strategies against invasive GBS infections.

Detection of group B streptococcal colonization in pregnant women using direct latex agglutination testing of selective broth.

Simple SummaryThe bioactive properties of extracellular vesicles (EVs) in the physiological and pathophysiological conditions of pregnancy and cancers have been well investigated. However, the interaction of EVs and bacterial cells has not been studied yet. Transferring and releasing of cargos in EVs intracellularly impact the function of target cells. In this study, we investigated the effect of placental EVs on the growth of opportunistic pathogens such as Group B Streptococcus (GBS), which is a major cause of some complications of pregnancy. We found that placental micro-EVs or nano-EVs attenuated the growth of a Gram-positive bacterium, GBS. This attenuative effect at least partially required an interaction of placental EVs with GBS. Proteomic analysis showed that changes in protein synthesis or cellular energy in GBS may contribute to this inhibitory effect.Background: Like many other cell types, the human placenta produces large amounts of extracellular vesicles (EVs). Increasing evidence has shown that placental EVs contribute to the regulation of maternal immune and vascular systems during pregnancy via the transfer of their cargos. In this study, we investigated the effect of placental EVs on the growth of opportunistic pathogens that commonly colonise the female reproductive tract. Methods: Gram-positive bacterium Group B Streptococcus (GBS) and Gram-negative bacterium Escherichia coli (E. coli) were treated with placental EVs that were collected from placental explant cultures, and the growth, susceptibility, and resistance to antibiotics of the bacteria were measured. In addition, comparative proteomics analysis was also performed for the GBS with or without exposure to placental EVs. Results: When treated with placental micro-EVs or nano-EVs, the GBS growth curve entered the stationary phase earlier, compared to untreated GBS. Treatment with placental EVs also inhibited the growth of GBS on solid medium, compared to untreated GBS. However, these biological activities were not seen in E. coli. This attenuative effect required interaction of placental EVs with GBS but not phagocytosis. In addition, the susceptibility or resistance to antibiotics of GBS or E. coli was not directly affected by treatment with placental EVs. The proteomic and Western blotting analysis of GBS that had been treated with placental EVs suggested that the downregulation of cellular components and proteins associated with phosphorylation and cell energy in GBS may contribute to these attenuative effects. Conclusion: We demonstrated the attenuative effect of the growth of GBS treated with placental EVs. Downregulation of cellular components and proteins associated with phosphorylation and cell energy may contribute to the physiological changes in GBS treated with placental EVs.

After completing this article, readers should be able to: 1. Describe the current literature on surveillance studies and patient outcomes regarding group B Streptococcus (GBS) disease. 2. Discuss the current perinatal GBS prevention guidelines. 3. Describe the limitations of the “limited evaluation” in assessing newborns at risk for GBS disease. 4. Delineate the proposed management of asymptomatic infants at risk for GBS disease, with the goal of decreasing unnecessary testing and avoiding prolonged hospitalization. Group B Streptococcus (GBS), also known as S agalactiae , is an encapsulated gram-positive bacterium that is a common inhabitant of the human gastrointestinal and genitourinary tracts. Despite recent reductions in incidence, it remains the most common cause of neonatal bacterial infections in most developed countries. The most desirable approach suggested to eliminate neonatal GBS infection is the use of GBS vaccines prior to or early in pregnancy. However, until effective GBS vaccines become available, screening pregnant women for GBS colonization and providing intrapartum antibiotic prophylaxis (IAP) will continue to be the mainstay for prevention of GBS infection in neonates, as suggested by the Centers for Disease Control and Prevention (CDC). A 70% decline in the rate of early-onset GBS disease followed the introduction of the first national consensus guidelines in 1996. In 2002, new national guidelines were released based on evidence that the screening-based strategy was superior to a risk factor-based strategy for preventing GBS infections in the neonate. As a result of many obstetricians adopting the screening-based strategy, CDC data from 2004 showed a further decline in the incidence of early-onset GBS infection to 0.34 cases per 1,000 live births. This surpasses the Healthy People 2010 objective of a reduction in the incidence of early-onset disease to 0.5 cases per 1,000 live births for all races. It should be mentioned that different countries may demonstrate different results, but …

Objective To analyze the clinical features of neonatal purulent meningitis (NPM) caused by Gram-positive and Gram-negative bacteria. Method From January 2008 to December, 2015, the clinical data of NPM with positive cerebrospinal-fluid (CSF) culture admitted to Children′s Hospital of Fudan University were reviewed retrospectively. Patients were assigned into Gram-positive group and Gram-negative group according to CSF culture, and general information, clinical presentation, laboratory examination and outcome were compared between the two groups. Wilcoxon Rank-Sum test was used to compare means. Proportions were compared using χ2 test. Result A total of 82 NPM patients with positive CSF culture were enrolled in the study, and 44 (53.7%) were male. The average gestational age was 38.5 (35.6, 39.6) weeks and the mean birth weight was 3 100 (2 600, 3 380) grams. 16 (19.5%) cases were early-onset meningitis and 66(80.5%) were late-onset. In 82 cases, 43 (52.4%) showed Gram-positive bacteria and 39(47.6%) Gram-negative in CSF culture. The five most common pathogens were escherichia coli(22 cases, 26.8%), group B streptococcus (GBS) (10 cases, 12.2%), enterococcus faecium (8 cases, 9.8%), coagulase-negative staphylococcus(8 cases, 9.8%) and klebsiella pneumoniae(5 cases, 6.1%). In early-onset patients, the main causative pathogens isolated from CSF were GBS (3 cases, 18.8%) and enterococcus (3 cases, 18.8%) . Escherichia coli (20 cases, 30.3%) and coagulase-negative staphylococcus(8 cases, 12.1%) were the most common pathogens in late-onset patients. Gram-positive group and Gram-negative group had similar clinical presentation(P>0.05). The ratio of patients with blood C-reactive protein>8 mg/L in Gram-negative group was higher than that in Gram-positive group(P<0.05). Those with Gram-negative bacterial meningitis had a higher incidence of hydrocephalus than Gram-positive (P<0.05). Conclusion The main pathogens of NPM are escherichia coli and GBS. Neonates with Gram-positive bacteria meningitis have similar clinical presentation with those with Gram-negative meningitis, but have different laboratory examination and complication characteristics. Key words: Meningitis, bacterial; Gram-positive bacteria; Gram-negative bacteria; Clinical features

BackgroundOne million neonates die each year in low- and middle-income countries because of neonatal sepsis; group B Streptococcus (GBS) and Escherichia coli are the leading causes. In sub-Saharan Africa, epidemiological data on vaginal GBS and E. coli carriage, a prerequisite for GBS and E. coli neonatal sepsis, respectively, are scarce but necessary to design and implement prevention strategies. Therefore, we assessed vaginal GBS and E. coli carriage rates and risk factors and the GBS serotype distribution in three sub-Saharan countries.MethodsA total of 430 women from Kenya, Rwanda and South Africa were studied cross-sectionally. Vaginal carriage of GBS and E. coli, and GBS serotype were assessed using molecular techniques. Risk factors for carriage were identified using multivariable logistic regression analysis.ResultsVaginal carriage rates in reference groups from Kenya and South Africa were 20.2% (95% CI, 13.7–28.7%) and 23.1% (95% CI, 16.2–31.9%), respectively for GBS; and 25.0% (95% CI, 17.8–33.9%) and 27.1% (95% CI, 19.6–36.2%), respectively for E. coli. GBS serotypes Ia (36.8%), V (26.3%) and III (14.0%) were most prevalent. Factors independently associated with GBS and E. coli carriage were Candida albicans, an intermediate vaginal microbiome, bacterial vaginosis, recent vaginal intercourse, vaginal washing, cervical ectopy and working as a sex worker. GBS and E. coli carriage were positively associated.ConclusionsReduced vaginal GBS carriage rates might be accomplished by advocating behavioral changes such as abstinence from sexual intercourse and by avoidance of vaginal washing during late pregnancy. It might be advisable to explore the inclusion of vaginal carriage of C. albicans, GBS, E. coli and of the presence of cervical ectopy in a risk- and/or screening-based administration of antibiotic prophylaxis. Current phase II GBS vaccines (a trivalent vaccine targeting serotypes Ia, Ib, and III, and a conjugate vaccine targeting serotype III) would not protect the majority of women against carriage in our study population.

Background: Group B Streptococcus (GBS) is a gram-positive bacterium and a major cause of bacterial infections in the newborns delivered by women whose rectum and vagina were colonized by GBS during pregnancy. Objectives: To study the association between maternal GBS recto-vaginal colonization and neonatal colonization and occurrence of early onset neonatal group B Streptococcal sepsis. Methodology: A prospective cohort study involving 28 mother-infant pairs of GBS positive and 28 negative controls. Results: Of the 196 pregnant women screened for GBS recto-vaginal colonization between 35-37weeks, 31 women were positive giving a prevalence rate of 15.8%. Three (3) cases were later excluded for different reasons, thus only 28 infants delivered to GBS-positive mothers and 28 infants delivered to GBS-negative mothers were followed up for signs and symptoms of sepsis. Of the 28 newborns delivered to GBS colonized mother, 12(43.0%) were colonized with GBS at birth compared to 2 (7.1%) colonized newborns delivered to GBS-negative pregnant women. An association was observed between maternal GBS recto-vaginal colonization and neonatal colonization (P=0.0003, RR: 2.25 CI:(1.45 – 3.49)) with a vertical transmission rate of 43% among the GBS colonized motherinfant pairs. A significant difference was also observed between the birth weights of infants delivered to GBSpositive mothers (3100.00 ± 392.8g) and GBS- negative mothers (3338.4 ± 338.4g) (P=0.018). Low social class was associated with higher GBS colonization rate (P = 0.029). A prevalence rate of 17.9/1000 births of GBS early sepsis was found in this study. Conclusion: Low social class increases the risk of maternal colonization by GBS, and maternal colonization in late third trimester is associated with newborn GBS colonization at birth.

Group B Streptococcus (GBS) is a Gram-positive human pathogen representing one of the most common causes of life-threatening bacterial infections such as sepsis and meningitis in neonates. Covalently polymerized pilus-like structures have been discovered in GBS as important virulence factors as well as vaccine candidates. Pili are protein polymers forming long and thin filamentous structures protruding from bacterial cells, mediating adhesion and colonization to host cells. Gram-positive bacteria, including GBS, build pili on their cell surface via a class C sortase-catalyzed transpeptidation mechanism from pilin protein substrates that are the backbone protein forming the pilus shaft and two ancillary proteins. Also the cell-wall anchoring of the pilus polymers made of covalently linked pilin subunits is mediated by a sortase enzyme. GBS expresses three structurally distinct pilus types (type 1, 2a and 2b). Although the mechanisms of assembly and cell wall anchoring of GBS types 1 and 2a pili have been investigated, those of pilus 2b are not understood until now. Pilus 2b is frequently found in ST-17 strains that are mostly associated with meningitis and high mortality rate especially in infants. In this work the assembly mechanism of GBS pilus type 2b has been elucidated by dissecting through genetic, biochemical and structural studies the role of the two pilus-associated sortases. The most significant findings show that pilus 2b assembly appears “non-canonical”, differing significantly from current pilus assembly models in Gram-positive pathogens. Only sortase-C1 is involved in pilin polymerization, while the sortase-C2 does not act as a pilin polymerase, but it is involved in cell-wall pilus anchoring. Our findings provide new insights into pili biogenesis in Gram-positive bacteria. Moreover, the role of this pilus type during host infection has been investigated. By using a mouse model of meningitis we demonstrated that type 2b pilus contributes to pathogenesis of meningitis in vivo.

Urinary tract infection (UTI) is one of the most common infections and costs millions of dollar each year to the health care industry. Escherichia coli is the causative agent responsible for over 80% of UTIs. However, other pathogens such as Group B streptococcus (GBS), a Grampositive bacterium, also cause UTI. In addition, GBS is an important commensal microbe in the female genital tract. Researchers have used various murine models to study mechanisms of disease pathogenesis for UTI and microbe colonisation of the genital tract. However, there is a lack of understanding of the pathogenic mechanisms and microbe virulence factors involved in UTI and genital tract colonisation due to both E. coli and GBS. This thesis reports on a series of experiments using murine models to better understand the pathogenesis of E. coli and GBS infection in the urogenital tract. It explores the use of several murine models to better understand host responses to these infections. In one series of experiments on both E. coli and GBS, murine models were utilised to define the global host immune response to these bacteria in UTI on a genome-wide scale with the aid of microarrays. Another series of experiments used a murine model of E. coli UTI to study the virulence factor α-hemolysin and how this factor influences host responses. The thesis also describes the development of a novel GBS long-term genital tract colonisation model in mice that was used to define the nature of GBS colonisation and survival in this infection. Thus, a series of novel murine models are described in the thesis that were applied in various host response studies and virulence assays to better understand how E. coli and GBS survive and cause infection in the urogenital tract in vivo. The application of murine models to study urogenital tract infection as described in this thesis provides researchers with a solid platform to examine the effects of virulence factors, and host responses in more detail in future studies. One particular area for future research relates to the specific series of experiments in which a murine UTI model was used to test the efficacy of prophylactic use of a novel E. coli 83972 ‘probi otic strain’ expressing a P fimbriae oligosaccharide receptor mimic to prevent acute infection. In this way, the data described in this thesis also provides vital new insight into how murine models can be used to test possible novel treatment strategies for preventing UTI.

Streptococcus agalactiae, a Gram-positive bacterium, causes invasive infection known as Group B streptococcal disease (GBS). It is a leading cause of neonatal death and complications prior to delivery. The burden of GBS is unknown in India despite the high incidence of preterm and stillbirths. In this study, we performed a narrative review of the available literature (published in the last 10 years) on the epidemiology of GBS, using PubMed and Google Scholar, to understand its impact in India and evaluate potential strategies to prevent the disease in the high-risk population, that is, neonates. The review showed that the incidence of early- and late-onset GBS in neonates (per 1000 live births) was in the ranges of 0.090–0.68 and 0.0–0.07 respectively. The overall case fatality rate reported in only one study was 0.63. In pregnant women, the prevalence of GBS colonization was 2–62% and its transmission to their newborns varied from 6.7% to 11.1%. The serotype distribution of GBS is unclear, but some studies reported the distribution of types Ia, Ib, II, III, V, VII among pregnant women in India. The associated risk factors for GBS colonization in pregnant women are unclear but a few studies suggest the role of age and multigravida, while the risk factors in neonates include preterm birth, prolonged rupture of membrane (⩾18 h), maternal fever, obstetric complications, and prolonged labor >18 h. Screening of GBS is not a routine practice in India and intrapartum antibiotics prophylaxis is limited to only in risk conditions to prevent neonatal disease transmission. A few studies also suggest that high birth rate, poor detection methods, and financial constraints limit routine GBS screening in a developing country such as India. Hence, maternal vaccination is the most promising strategy to prevent neonatal GBS and Pfizer’s hexavalent GBS conjugate vaccine (GBS6) is being developed for GBS neonatal disease.

Background: Group B streptococcus (GBS) and Listeria monocytogenes are members of the normal microbes of the female genital tract. During labour GBS and Listeria monocytogenes may infect the new-borns, leading to neonatal sepsis and meningitis. So far, there is no report on prevalence of GBS and Listeria monocytogenes among pregnant women in Mwanza. The objective of the study was to determine the magnitude of Group B Streptococcus and Listeria monocytogenes and its associated factors at Bugando Medical Centre, Mwanza, Tanzania. Methods: The study was a cross section conducted from 1 st November 2011 to 31 st May 2012 at Bugando Medical Centre in Mwanza, Tanzania. Vaginal and rectal swabs were obtained and cultured on 5% sheep blood agar and susceptibility testing done using disk diffusion technique. Results: A total of 295 pregnant women participated in the study. GBS strains were isolated from 28 (9.49%) and only two (0.68%) had isolates of Listeria spp. All GBS and Listeria spp. isolates were sensitive to penicillin and ampicillin. Eight GBS isolates were resistant to erythromycin (28.6%), seven GBS isolates were resistant to clindamycin (25%) and 15 of GBS isolates were resistant to tetracycline (53.6%). One Listeria spp isolate was resistant to cotrimoxazole. Pregnant women with no formal education and those dwelling in rural areas were more frequently colonized by GBS. Conclusion: There is a significant prevalence rate of GBS culture positive at Bugando Medical Centre with demonstrable resistant to some common antibiotics (tetracycline, erythromycin and Clindamycin). Screening for GBS should be instituted in Tanzania between 35 and 37 weeks of gestation coupled with regular check up for antimicrobial susceptibility pattern due to emerging resistance toward existing antibiotics.

In order to obtain reliable data on vaginal carriage of Streptococcus agalactiae in pregnant women and to formulate a prevention program of neonatal Group B Streptococcus (GBS) disease, we carried out a prospective cross sectional study for 6 months. The general objective of the study was to evaluate the prevalence of vaginal carriage and the resistance profile of GBS. The study involved 142 pregnant women presenting for antenatal care in Yaounde Gynecology-Obstetric and Pediatric Hospital (YGOPH). Participants were interviewed using a standard structure questionnaire. Low vaginal swabs were collected and cultured on specific media. A presumptive identification of isolates was made using standard bacteriological methods. Confirmative identification of Group B Streptococcus was done and antimicrobial sensitivity testing was performed. Among the 142 pregnant women GBS colonization was confirmed in 11 (7.7%). The rate of carriage was 3.8% in the first trimester, 7% in the second trimester and 11.1% in the third trimester. The predominant germ was Candida albicans with a frequency of 45.2% among the germs found in monomicrobial culture and Gardnerella vaginalis (77.8%) among the germs in polymicrobial culture, followed by Candida spp (11.8%), S. agalactiae (8.6%) and Escherichia coli (4.3%). The result of antimicrobial sensitivity testing showed that all the GBS strains were sensitive to major antibiotics drugs tested. The highest rates of resistance were found with gentamycin (100%) and Cefuroxim (81.8%). The vaginal carriage of GBS among pregnant women is still high. Thus, well-planned, prospective studies will be necessary to fully appreciate the magnitude of the problem of GBS in our hospitals. Key words: Group B Streptococcus, neonatal infections, antibiotic, low vaginal swabs.

Urinary tract infections (UTIs) are among the most common infections caused by both Gram-negative and Gram-positive bacteria, acquired in the community and hospitals. There are three main groups of UTIs: (i) lower UTIs that affect the urethra or the bladder, (ii) upper UTIs that affect the kidneys, or (iii) asymptomatic bacteriuria (ABU). Group B Streptococcus (GBS) is a Gram-positive bacteria known to cause a variety of infections in neonates, pregnant women, the elderly or immunocompromised individuals. GBS has been estimated to cause 1-2% of all single organism UTIs. GBS has been shown to form biofilms, on abiotic and biotic surfaces, protecting it from killing by antibiotics or host immune cells and promotes host colonisation. Various factors have been shown to affect the biofilm forming ability of GBS. Here we determined that LB supplemented with glucose was the optimal media for biofilm formation by a strong biofilm forming strain. We then investigated the biofilm forming phenotype of 292 clinical GBS isolates that presented with asymptomatic, acute, or recurrent infection. We found that there was no significant difference in the biofilm forming ability across the clinical presentations. We also showed a significant reduction in the biofilm forming ability of a strong biofilm forming strain and its isogenic maeK and maeE mutants in LB supplemented with 1% glucose. A multiplex PCR screen for genes encoding bsaB, pil1, pil2a, and pil2b found that there was no significant difference in the number of strains that had the right sized fragments for all four genes across the three clinical presentations. We also found that there was a significant difference in the proportion of strains that had the right sized fragments for the pil genes across the three different levels of biofilm activity under shaking conditions. High biofilm forming strains had the lowest proportion of strains that possessed all four genes, compared to low and medium biofilm formers. Lastly, we assessed the haemolytic activity of the strains by growing them on tryptic soy agar plates supplemented with 5% horse blood and found that asymptomatic strains had a significantly higher number of strains with high haemolytic activity compared to acute and recurrent strains.

Group B Streptococcus (GBS) is a leading pathogen responsible for fatal infections in newborns primarily due to vertical transmission from colonized mothers. Cases of invasive GBS infections in adults have also increased and attracted attention recently. To comprehensively understand the evolving burden of vaginal GBS carriage in pregnant and non-pregnant women, as well as the trends in invasive GBS diseases and antibiotic resistance in China, we conducted a retrospective study using data from a large tertiary hospital in Beijing from 2013 to 2023. Over the past decade, improvements in GBS screening methods for pregnant women have significantly increased the GBS recovery rate. The detection rate of GBS and its proportion among vaginal pathogens have shown a gradual increase in GBS colonization in both pregnant and non-pregnant women. An analysis of vaginal pathogen composition revealed variations in GBS prevalence across different age groups, as well as a potential competitive relationship between GBS and Enterococcus faecalis in the vaginal environment. Additionally, we analyzed 165 invasive GBS cases, including three in newborns. The incidence of invasive GBS cases has risen since 2016, particularly among individuals over the age of 40. The 5,858 GBS isolates exhibited notably high resistance rates to erythromycin (72.2%), clindamycin (60%), and levofloxacin (50.1%), with 30.8% classified as multidrug-resistant. Importantly, invasive GBS strains exhibited a higher resistance rate to levofloxacin (61.2%) compared to colonizing strains (49.8%). This study highlights the importance of continuous screening and monitoring for GBS, especially given the concerning antibiotic resistance rates of GBS.IMPORTANCEGroup B Streptococcus (GBS) is an important pathogen that commonly causes infections in newborns and the elderly. This retrospective study provides a comprehensive analysis of GBS strains isolated from a large tertiary hospital in Beijing between 2013 and 2023, revealing an increasing colonization rate of GBS in both pregnant and non-pregnant women. Analysis of vaginal pathogens indicates a growing proportion of GBS among vaginal pathogens. Additionally, the high resistance rates of GBS to erythromycin, clindamycin, and levofloxacin, as well as the prevalence of multidrug resistance, are issues that merit attention. We also examined the differences in resistance rates of GBS strains from various sample types, finding that the levofloxacin resistance rate in GBS strains causing invasive infections was significantly higher than in colonizing strains. This study provides new data and insights for clinical research on GBS.