A review of antibiotic resistance in Group B Streptococcus: the story so far

Emergence of a novel group B streptococcus CC61 clade associated with human infections in southern China

OBJECTIVES

Emerging human pathogens of animal origin have become an increasing public health concern in recent years. The aim of this study was to investigate the transmission of group B streptococcus (GBS) clonal complex (CC) 61 strains in the southern Chinese population and analyze their genetic characteristics.

METHODS

Whole-genome sequencing was performed on 693 clinical isolates of GBS collected from southern China between 2016 and 2021, and the prevalence of human CC61 isolates was investigated by genomic epidemiology. Phylogenetic analysis and Bayesian analysis of population structure were used to define genetic clades by combining CC61 genomes from global sources. Unique characteristics of human CC61 isolates were analyzed by comparison with the genomes of other isolates.

RESULTS

We identified 21 CC61 isolates from 19 patients (including four neonates), most of which belonged to sequence type (ST) 929 (n=17) and a few to ST931 (n=2) and ST61 (n=2). Phylogenetic analysis showed that the ST929 and ST931 isolates formed a novel clade associated with human infections (CC61H), which is a sister clade to the traditional bovine CC61 isolates. Population structure analysis indicated that CC61H has developed a unique population structure distinct from known lineages, representing an as-yet-unknown lineage. Comparative genomic analysis revealed that the epidemic success of CC61H in southern China was associated with the horizontal transfer of antibiotic resistance and virulence gene clusters. The insertion of a gene cluster encoding pilus island 1 may have contributed to the higher prevalence of ST929 relative to ST931. Furthermore, novel variants of the major pilin subunits BP-1 and BP-2b and the bacterial adhesin bibA were identified in CC61H, with bibA acquiring a pathogenic fragment of the homologous gene from the neonatal hypervirulent lineage CC17.

CONCLUSIONS

A novel clade of GBS CC61 associated with human infections was discovered in southern China. Given its multidrug resistance, high virulence and genomic characterization, the surveillance of CC61H strains should be more highly prioritized.

The increasing burden of group B Streptococcus from 2013 to 2023: a retrospective cohort study in Beijing, China

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.

Respiratory pathogens carriage in guinea pigs raised as livestock in Ecuador: A proxy to study a neglected reservoir for zoonotic transmission in the Andean Region

In the Andean region of South America, guinea pigs (Cavia porcellus) are raised as livestock in close contact with other domestic animals and humans. Although the susceptibility of guinea pigs to being affected by a wide range of diseases is well known as a laboratory animal model, there are a few reports about the potential role of zoonotic pathogens in livestock guinea pigs. In this work, we analyzed the nasopharyngeal carriage of respiratory pathogenic viruses and bacteria in guinea pigs from farms in Ecuador. We isolated streptococci and aerococci cultures that were analyzed for species identification by MALDI-TOF MS. Several species, including Streptococcus pneumoniae, S. pseudopneumoniae, S. oralies, and S. mitis were found. Moreover, strains resistant to antibiotics like levofloxacin, erythromycin, and sulfamethoxazole-trimethoprim were also found. Our results suggest the role of guinea pigs as a zoonotic reservoir for occupational exposure to respiratory pathogens in the Andean region of South America, where guinea pig farming is an important industry.

High-Throughput Shotgun Metagenomics of Microbial Footprints Uncovers a Cocktail of Noxious Antibiotic Resistance Genes in the Winam Gulf of Lake Victoria, Kenya

Background: A diverse range of pollutants, including heavy metals, agrochemicals, pharmaceutical residues, illicit drugs, personal care products, and other anthropogenic contaminants, pose a significant threat to aquatic ecosystems. The Winam Gulf of Lake Victoria, heavily impacted by surrounding human activities, faces potential contamination from these pollutants. However, studies exploring the presence of antibiotic resistance genes (ARGs) in the lake remain limited. In the current study, a shotgun metagenomics approach was employed to identify ARGs and related pathways. Genomic DNA was extracted from water and sediment samples and sequenced using the high-throughput Illumina NovaSeq platform. Additionally, phenotypic antibiotic resistance was assessed using the disk diffusion method with commonly used antibiotics. Results: The analysis of metagenomes sequences from the Gulf ecosystem and Comprehensive Antibiotic Resistance Database (CARD) revealed worrying levels of ARGs in the lake. The study reported nine ARGs from the 37 high-risk resistant gene families previously documented by the World Health Organization (WHO). Proteobacteria had the highest relative abundance of antibiotic resistance (53%), Bacteriodes (4%), Verrucomicrobia (2%), Planctomycetes Chloroflexi, Firmicutes (2%), and other unclassified bacteria (39%). Genes that target protection, replacement, change, and antibiotic-resistant efflux were listed in order of dominance. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed antibiotic resistance to beta-lactamase and vancomycin. Phenotypic resistance to vancomycin, tetracycline, sulfamethoxazole, erythromycin, trimethoprim, tetracycline, and penicillin was reported through the zone of inhibition. Conclusions: This study highlights that the Winam Gulf of Lake Victoria in Kenya harbors a diverse array of antibiotic-resistant genes, including those conferring multidrug resistance. These findings suggest that the Gulf could be serving as a reservoir for more antibiotic-resistant genes, posing potential risks to both human health and aquatic biodiversity. The insights gained from this research can guide policy development for managing antibiotic resistance in Kenya.

Genotype Distribution and High-Risk Factors Analysis of Group B Streptococcus in Late-Stage Pregnant Women in the Linyi Region

Objective: To understand the colonization status of Group B Streptococcus (GBS) in the reproductive tract of pregnant women in the Linyi region, the drug resistance, genotype distribution, and molecular epidemiological characteristics of GBS, and to explore the high-risk factors for GBS infection in late-stage pregnant women. Methods: A total of 3269 pregnant women at 35-37 weeks of gestation who visited the Obstetrics Department of Linyi Maternal and Child Health Hospital from January 2019 to December 2021 were selected as the study subjects. Vaginal and rectal swabs were collected for GBS culture. Based on the culture results, they were divided into positive and negative groups. The high-risk factors such as age, BMI index, education level, pregnancy vomiting, and liver function indicators of the two groups were analyzed. Drug sensitivity test, multilocus sequence typing (MLST) gene typing, and virulence factor detection were performed on GBS (+) strains. Results: The infection rate of GBS in the reproductive tract of pregnant women in late pregnancy in the Linyi region was 7.07% (231/3269). The analysis of high-risk factors showed that having a college degree or above and absence of pregnancy vomiting; elevated levels of alanine aminotransferase, albumin, globulin, direct bilirubin, glutamyl transferase, and total bile acids; and decreased levels of alkaline phosphatase and lactate dehydrogenase were high-risk factors for GBS infection (p < 0.05). The MLST results showed that a total of 189 GBS strains were identified with 20 genotypes, the top four being ST10 type (25.40%), ST19 type (17.99%), ST529 type (13.76%), and ST862 type (12.70%). The 20 ST came from 8 CCs, with the main CC groups being CC12 (29.11%), CC19 (24.87%), CC103 (18.00%), and CC327 (13.76%). GBS strains showed high sensitivity to vancomycin, penicillin, and levofloxacin, all being 100%; sensitivity to erythromycin, clindamycin, compound novobiocin, and tetracycline was relatively low; there were statistically significant differences in resistance to erythromycin, clindamycin, and levofloxacin among different genotypes of GBS (p < 0.05). The detection rates of GBS virulence factors hylB (81.46%) and scpB (80.98%) were the highest. In ST10 type, > 90% of strains carried bac, bca, hylB, and scpB; in ST19 and ST529, > 90% of strains carried hylB and scpB; and in ST862, > 90% of strains carried CPSIII. Conclusion: The colonization rate of GBS in the reproductive tract of pregnant women in late pregnancy in the Linyi region is 7.07%. Having a college degree or above, absence of pregnancy vomiting, elevated levels of albumin, globulin, direct bilirubin, glutamyl transferase, and total bile acids, and decreased levels of alkaline phosphatase and lactate dehydrogenase are high-risk factors for GBS infection; ST10, ST19, ST529, and ST862 are the main genotypes prevalent in this region; there are regional differences in the distribution of GBS genotypes and CC groups; there are statistically significant differences in the distribution of virulence factors among GBS strains with different MLST genotypes (p < 0.05); GBS shows high sensitivity to penicillin drugs and can still be used as the preferred medication for the prevention and treatment of GBS infection.

Endolysin EN572-5 as an alternative to treat urinary tract infection caused by Streptococcus agalactiae

Streptococcus agalactiae (Group B Streptococcus, GBS) is an opportunistic pathogen causing urinary tract infection (UTI). Endolysin EN572-5 was identified in prophage KMB-572-E of the human isolate Streptococcus agalactiae KMB-572. The entire EN572-5 gene was cloned into an expression vector and the corresponding recombinant protein EN572-5 was expressed in Escherichia coli in a soluble form, isolated by affinity chromatography, and characterized. The isolated protein was highly active after 30 min incubation in a temperature range of - 20 °C to 37 °C and in a pH range of 5.5-8.0. The endolysin EN572-5 lytic activity was tested on different Streptococcus spp. and Lactobacillus spp. The enzyme lysed clinical GBS (n = 31/31) and different streptococci (n = 6/8), and also exhibited moderate lytic activity against UPEC (n = 4/4), but no lysis of beneficial vaginal lactobacilli (n = 4) was observed. The ability of EN572-5 to eliminate GBS during UTI was investigated using an in vitro model of UPSA. After the administration of 3 μM EN572-5, a nearly 3-log decrease of urine bacterial burden was detected within 3 h. To date, no studies have been published on the use of endolysins against S. agalactiae during UTI. KEY POINTS: • A lytic protein, EN572-5, from a prophage of a human GBS isolate has been identified. • This protein is easily produced, simple to prepare, and stable after lyophilization. • The bacteriolytic activity of EN572-5 was demonstrated for the first time in human urine.

Antibiotic Resistance and Serotypes Distribution in Streptococcus agalactiae Bulgarian Clinical Isolates During the Years of 2021-2024

Streptococcus agalactiae (group B Streptococcus, GBS) is an important human and animal pathogen. In recent years, the number of streptococcal isolates resistant to antimicrobial agents has increased in many parts of the world. Various mechanisms of antimicrobial resistance and capsular serotypes of GBS with different geographical distributions can be found. A prospective cross-sectional study was conducted from September 2021 to May 2024. The survey included 257 GBS isolates from Bulgarian inpatients and outpatients with streptococcal infections. Antibiotic resistance genes and capsular serotypes were detected and evaluated using polymerase chain reaction (PCR). We classified GBS isolates into groups according to their source as vaginal samples (191) and extra-vaginal samples (66), subdivided as invasive (36) and non-invasive specimens (30). The most common serotypes were Ia (26.5%), III (20.2%), and V (19.8%). Antimicrobial susceptibility testing revealed that all examined isolates were susceptible to penicillin and vancomycin. Resistance to macrolides, lincosamides, and tetracyclines was observed in 60.3%, 24.9%, and 89.1% of the isolates. The distribution of phenotypes was cMLSb 47.4%, iMLSb 30.8%, M-type 21.2%, and L-type 0.6%. PCR analysis revealed nine genes associated with macrolide and lincosamide resistance: ermB (54.2%), ermA/TR (30.3%), mefA (20.7%), ermC (18.1%), msrD (14.8%), mefE (8.4%), IsaC (8.4%), InuB (7.7%), and IsaE (6.5%). Two genes linked to tetracycline resistance tetM (89.1%) and tetO (14.4%) were detected. Compared to the previous period, we observed increased antibiotic resistance. There was no statistical significance between the distribution of serotypes and antimicrobial non-susceptibility depending on the sample source.

Molecular evidence that GBS early neonatal sepsis results from ascending infection: comparative hybrid genomics analyses show that microorganisms in the vaginal ecosystem, amniotic fluid, chorioamniotic membranes, and neonatal blood are the same

OBJECTIVES

Streptococcus agalactiae, or Group B Streptococcus (GBS), is a leading cause of neonatal sepsis. Materno-fetal transmission of the microorganisms present in the lower genital tract/perineum is considered to be the most frequent mode for acquisition of infection. It has also been proposed that, in a subset of cases, GBS causes acute chorioamnionitis, intraamniotic infection, and fetal/neonatal sepsis. However, the evidence to support this ascending pathway is derived from microbiologic studies that rely on cultivation methods, which do not have the resolution to determine if the microorganisms causing neonatal sepsis are the same as those found in the amniotic fluid and the vaginal ecosystem.

METHODS

We used whole genome sequencing of the microorganisms isolated from the vagina, amniotic fluid, chorioamniotic membranes, and neonatal blood (four isolates) in a case of early neonatal sepsis. Using hybrid genome assembly, we characterized the genomic features including virulence factors and antimicrobial resistance in four isolates from the same mother, placenta, and newborn.

RESULTS

Whole genome sequencing revealed that the microorganisms in the four clinical isolates corresponded to S. agalactiae sequence type 1, clonal complexes 1, and serotype Ib. Comparative genomic analysis illustrated similar DNA sequences of the four genomes.

CONCLUSIONS

This study presents the first evidence of the genomic similarity of microorganisms in the vaginal ecosystem, the space between the chorioamniotic membranes of the placenta, amniotic fluid, and neonatal blood.

Prevalence and Antibiotic Resistance of Streptococcus agalactiae in Women of Childbearing Age Presenting Urinary Tract Infections from Western Romania

Urinary tract infections (UTIs) are a common bacterial infection in women of childbearing age. Streptococcus agalactiae (Group B Streptococcus-GBS), a rare causative pathogen of UTIs in this population, is particularly important due to the potential risk during pregnancy, when it can lead to life-threatening neonatal infections. The current study analyzed 17,273 urine samples collected from consecutive women aged 18-45 years from Arad County, Western Romania. A total of 2772 samples tested positive for UTIs. In 130 cases, GBS was identified as the causative agent. Univariate logistic regression analysis revealed that women aged 25-34 years were more likely to test positive for GBS than those aged 18-24 years (cOR = 1.91, 95% CI: 1.07-3.43, p = 0.03). Antibiotic sensitivity testing revealed that all GBS strains were fully sensitive to penicillin, ampicillin, and vancomycin. High resistance was observed for clindamycin (77.34%) and tetracycline (88.46%). While GBS was found to be a rare pathogen in UTIs, our results underscore the importance of monitoring GBS in women of childbearing age, especially due to its risks during pregnancy, and emphasize the need for appropriate antibiotic management.

Antibiotic Resistance and Presence of Persister Cells in the Biofilm-like Environments in Streptococcus agalactiae

Objectives: This study investigated antibiotic resistance and presence of persister cells in Streptococcus agalactiae strains belonging to capsular types Ia/ST-103, III/ST-17, and V/ST-26 in biofilm-like environments. Results: S. agalactiae strains were susceptible to penicillin, clindamycin, and erythromycin. Resistance genes were associated with tetM (80%), tetO (20%), ermB (80%), and linB (40%). Persister cells were detected in bacterial strains exposed to high concentrations of penicillin, clindamycin, and erythromycin. S. agalactiae capsular type III/ST-17 exhibited the highest percentage of persister cells in response to penicillin and clindamycin, while type Ia/ST-103 presented the lowest percentages of persister cells for all antimicrobials tested. Additionally, persister cells were also detected at lower levels for erythromycin, regardless of capsular type or sequence type. Further, all S. agalactiae isolates presented efflux pump activity in ethidium bromide-refractory cell assays. LIVE/DEAD fluorescence microscopy confirmed the presence of >85% viable persister cells after antibiotic treatment. Conclusions: These findings suggest that persister cells play a key role in the persistence of S. agalactiae during antibiotic therapy, interfering with the treatment of invasive infections. Monitoring persister formation is crucial for developing strategies to combat recurrent infections caused by this pathogen.

The impact of butyrate on group B Streptococcus-induced intestinal barrier disruption

Group B Streptococcus (Streptococcus agalactiae; GBS) is a leading cause of neonatal sepsis worldwide. As a pathobiont of the intestinal tract, it is capable of translocating across barriers leading to invasive disease. Neonatal susceptibility to invasive disease stems from immature intestinal barriers. GBS intestinal colonization induces major transcriptomic changes in the intestinal epithelium related to barrier function. Butyrate, a microbial metabolite produced by fermentation of dietary fiber, bolsters intestinal barrier function against enteric pathogens, and these effects can be transferred in utero via the placenta to the developing fetus. Our aim was to determine if butyrate mitigates GBS disruption of intestinal barriers. We used human intestinal epithelial cell (IEC) lines to evaluate the impact of butyrate on GBS-induced cell death and GBS adhesion and invasion. IECs and human fetal tissue-derived enteroids were used to evaluate monolayer permeability. We evaluated the impact of maternal butyrate treatment (mButyrate) using our established mouse model of neonatal GBS intestinal colonization and late-onset sepsis. We found that butyrate reduces GBS-induced cell death, GBS invasion, monolayer permeability, and translocation in vitro. In mice, mButyrate decreases GBS intestinal burden in offspring. Our results demonstrate the importance of bacterial metabolites, such as butyrate, in their potential to bolster epithelial barrier function and mitigate neonatal sepsis risk.IMPORTANCEGroup B Streptococcus (GBS) is a leading cause of neonatal morbidity and mortality. It is a commensal of the intestines that can translocate across barriers leading to sepsis in vulnerable newborns. With the rise in antibiotic-resistant strains and no licensed vaccine, there is an urgent need for preventative strategies. Butyrate, a short-chain fatty acid metabolized in the gut, enhances barrier function against pathogens. Importantly, butyrate is transferred in utero, conferring these benefits to infants. Here, we demonstrate that butyrate reduces GBS colonization and epithelial invasion. These effects were not microbiome-driven, suggesting butyrate directly impacts epithelial barrier function. Our results highlight the potential impact of maternal dietary metabolites, like butyrate, as a strategy to mitigate neonatal sepsis risk.

Novel Insights on Group B Streptococcus in Pregnancy

Group B Streptococcus (GBS) is a frequent colonizer of the human genital and gastrointestinal tract. In pregnant or postpartum persons, colonization is often asymptomatic and can contribute to infectious morbidity in both the parturient and the newborn. The prevalence of invasive GBS disease has dramatically decreased over the past 3 decades. However, despite standardized clinical algorithms, GBS disease remains a public health concern. Our review summarizes the GBS bacteria pathophysiology, morbidity, management guidelines, and summarizes ongoing research. While novel testing and parturient vaccination are being explored, barriers exist, preventing guideline updates and widespread implementation.

Molecular Basis of Antimicrobial Resistance in Group B Streptococcus Clinical Isolates from Saudi Arabia

Published data on the molecular mechanisms underlying antimicrobial resistance in Group B Streptococcus (GBS) isolates from Saudi Arabia are lacking. Here, we aimed to determine the genetic basis of resistance to relevant antibiotics in a collection of GBS clinical isolates (n = 204) recovered from colonized adults or infected patients and expressing serotypes Ia, Ib, II, III, V, and VI. Initial susceptibility testing revealed resistance to tetracycline (76.47%, n = 156/204), erythromycin (36.76%, n = 75/204), clindamycin (25.49%, n = 52/204), levofloxacin (6.37%, n = 13/204), and gentamicin (2.45%, n = 5/204). Primers designed for the detection of known resistance determinants in GBS identified the presence of erm(A), erm(B), mef(A), and/or lsa(C) genes at the origin of resistance to macrolides and/or clindamycin. Of these, erm(B) and erm(A) were associated with the cMLSB (n = 46) and iMLSB (n = 28) phenotypes, respectively, while mef(A) was linked to the M phenotype (n = 1) and lsa(C) was present in isolates with the L phenotype (n = 8). Resistance to tetracycline was mainly mediated by tet(M) alone (n = 112) or in combination with tet(O) (n = 10); the remaining isolates carried tet(O) (n = 29), tet(L) (n = 2), or both (n = 3). Isolates resistant to gentamicin (n = 5) carried aac(6')-Ie-aph(2')-Ia, and those exhibiting resistance to levofloxacin (n = 13) had alterations in GyrA and/or ParC. Most isolates with the erm gene (93.24%, n = 69/74) also had the tet gene and were therefore resistant to erythromycin, clindamycin, and tetracycline. Overall, there were no clear associations between serotypes and resistance genotypes except for the presence of erm(B) in serotype Ib isolates. Dissemination of antibiotic resistance genes across different serotypes represents a public health concern that requires further surveillance and appropriate antibiotic use in clinical practice.

Molecular characterization, antimicrobial resistance and invasion of epithelial cells by Streptococcus agalactiae strains isolated from colonized pregnant women and newborns in Rio de Janeiro, Brazil

AIMS

To evaluate the prevalence, molecular characteristics, antimicrobial susceptibility, and epithelial invasion of Streptococcus agalactiae strains isolated from pregnant women and newborns in Rio de Janeiro, Brazil.

METHODS AND RESULTS

A total of 67 S. agalactiae isolates, 48 isolates from pregnant women and 19 from neonates, were analyzed. Capsular type Ia and V were predominant (35.8%/each). The multilocus sequence typing analysis revealed the presence of 19 STs grouped into 6 clonal complexes with prevalence of CC17/40.3% and CC23/34.3%. The lmb and iag virulence genes were found in 100% of isolates. Four S. agalactiae strains, belonging to CC17/ST1249 and CC23/ST23, were able to adhere to A549 respiratory epithelial cells. Antimicrobial resistance was verified mainly to tetracycline (85%), erythromycin (70.8%), and clindamycin (58.3%). Four S. agalactiae isolates were multidrug resistant. The resistance genes tested were found in 92.5% of isolates for tetM, 58.2% for ermB, 28.4% for mefAE, and 10.4% for tetO.

CONCLUSION

The study showed a high prevalence of virulence and antimicrobial genes in S. agalactiae strains isolated from pregnant women and newborns, supporting the idea that continued surveillance is necessary to identify risk factors and perform long-term follow-up in pregnant women and neonates in Rio de Janeiro.

Vertical Transmission of Group B Streptococcus, Prevalence, Associated Factors, and Antimicrobial Susceptibility Profile among Newborns Delivered at Health Facilities in Jigjiga City, Ethiopia

Background

Group B Streptococcus (GBS) colonizes the rectovaginal area of women and vertically transmitted to neonates. This bacterium has been linked to severe neonatal complications including pneumonia, septicemia, and meningitis. GBS shows an increased resistance to commonly used antibiotics. Thus, we assessed the vertical transmission, contributing factors, and antimicrobial resistance patterns of GBS among newborns delivered at selected Hospitals in Jigjiga City.

Methods

Hospital-based cross-sectional study was conducted from 1st June 2022 to 30th April 2023. A total of 849 pregnant women admitted to delivery wards from two hospitals were screened for GBS colonization. Subsequently, 162 GBS-colonized pregnant women and their newborn babies were included. A semistructured questionnaire and a review of medical records were used to collect the sociodemographic and clinical characteristics of the study participants. Trained nurses collected swab samples from the vaginal-rectal area of pregnant women and the nasal, ear canal, and umbilical areas of newborn babies. Samples were inoculated on Todd Hewitt broth media supplemented with gentamycin and nalidixic acid and then subcultured on blood agar. Colony characteristics, Gram stain, and catalase test were used for identification. All gram-positive cocci, B-hemolytic, and catalase-negative isolates were further identified using Christie-Atkins-Munch-Petersen and a bacitracin test. The modified Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility testing. Data were analyzed using SPSS version 26. Logistic regression analysis was used to determine the factors associated with vertical transmission of GBS, and statistical significance was set at p values <0.05.

Result

The overall vertical transmission rate was 41.4% (67/162). History of preterm labor (Adjusted odds ratio (AOR) = 2.25; 95% CI: 1.11, 4.59), history of urinary tract infection (UTI) at current pregnancy (AOR = 2.25; 95% CI: 1.11, 4.59), and prolonged rupture of membranes greater than 18 hours (AOR = 2.23; 95% CI: 1.13, 4.4) were significantly associated with vertical transmission of GBS from previously colonized mothers to their newborn babies. Regarding GBS antibiotic susceptibility profile, a significant degree of resistance was observed to penicillin (29.9%), tetracycline (22.4%), ampicillin (20.9%), and clindamycin (19.4%).

Conclusion

Our study documented a high prevalence of vertical transmission rate of GBS from pregnant women to their babies, with an overall transmission rate of 41.4%. The study identified the presence of antimicrobial-resistant GBS to penicillin, ampicillin, clindamycin, ciprofloxacin, and chloramphenicol. The organism was susceptible to vancomycin, followed by azithromycin, ceftriaxone, and erythromycin. Our study also reported MDR at 13.4%. Based on our findings, there is a need for antenatal culture-based GBS screening, maternal vaccination, and large-scale epidemiological and serotype identification studies to be put into practice in the study area.

The role of vaccines in reducing antimicrobial resistance: A review of potential impact of vaccines on AMR and insights across 16 vaccines and pathogens

In 2019, an estimated 4.95 million deaths were linked to antimicrobial resistance (AMR). Vaccines can prevent many of these deaths by averting both drug-sensitive and resistant infections, reducing antibiotic usage, and lowering the likelihood of developing resistance genes. However, their role in mitigating AMR is currently underutilized. This article builds upon previous research that utilizes Vaccine Value Profiles-tools that assess the health, socioeconomic, and societal impact of pathogens-to inform vaccine development. We analyze the effects of 16 pathogens, covered by Vaccine Value Profiles, on AMR, and explore how vaccines could reduce AMR. The article also provides insights into vaccine development and usage. Vaccines are crucial in lessening the impact of infectious diseases and curbing the development of AMR. To fully realize their potential, vaccines must be more prominently featured in the overall strategy to combat AMR. This requires ongoing investment in research and development of new vaccines and the implementation of additional prevention and control measures to address this global threat effectively.

Comparative Genomic Analysis of Prophages in Human Vaginal Isolates of Streptococcus agalactiae

Prophages, viral genomes integrated into bacterial genomes, are known to enhance bacterial colonization, adaptation, and ecological fitness, providing a better chance for pathogenic bacteria to disseminate and cause infection. Streptococcus agalactiae (Group B Streptococcus or GBS) is a common bacterium found colonizing the genitourinary tract of humans. However, GBS-colonized pregnant women are at risk of passing the organism to the neonate, where it can cause severe infections. GBS typically encode one or more prophages in their genomes, yet their role in pathogen fitness and virulence has not yet been described. Sequencing and bioinformatic analysis of the genomic content of GBS human isolates identified 42 complete prophages present in their genomes. Comparative genomic analyses of the prophage sequences revealed that the prophages could be classified into five distinct clusters based on their genomic content, indicating significant diversity in their genetic makeup. Prophage diversity was also identified across GBS capsule serotypes, sequence types (STs), and clonal clusters (CCs). Comprehensive genomic annotation revealed that all GBS strains encode paratox, a protein that prevents the uptake of DNA in Streptococcus, either on the chromosome, on the prophage, or both, and each prophage genome has at least one toxin-antitoxin system.

Current research update on group B streptococcal infection related to obstetrics and gynecology

Group B streptococcal (GBS) is a Gram-positive bacterium that is commonly found in the gastrointestinal tract and urogenital tract. GBS infestation during pregnancy is a significant contributor to maternal and neonatal morbidity and mortality globally. This article aims to discuss the infectious diseases caused by GBS in the field of obstetrics and gynecology, as well as the challenges associated with the detection, treatment, and prevention of GBS.

Incidence of group B streptococcus early-onset sepsis in term neonates with second-line prophylaxis maternal intrapartum antibiotics: a multicenter retrospective study

BACKGROUND

The difference in the incidence of early-onset sepsis caused by group B streptococcus among term neonates whose mothers received first-line vs second-line intrapartum prophylaxis is poorly described.

OBJECTIVE

This study aimed to compare the incidence of group B streptococcus early-onset sepsis among term neonates born to mothers who receive first-line, second-line, or no intrapartum antibiotics and to describe the short-term and survival outcomes of neonates who developed group B streptococcus early-onset sepsis stratified by maternal antepartum prophylaxis.

STUDY DESIGN

This was a retrospective review of electronic medical records. We queried the Pediatrix Medical Group Clinical Data Warehouse to evaluate the outcomes of term neonates born to group B streptococcus positive mothers between 2003 and 2020 and compared the incidence and outcomes of neonates with group B streptococcus early-onset sepsis whose mothers received first-line vs second-line or no intrapartum prophylaxis.

RESULTS

Among the 496,180 neonates, 104,196 (21%) were born to mothers who were group B streptococcus positive. Of 97,983 mothers who were group B streptococcus positive with adequate prenatal antibiotic documentation, 49,234 (50%), 12,679 (13%), and 36,070 (37%) received first-line, second-line, and no intrapartum prophylaxis, respectively. The incidence of group B streptococcus early-onset sepsis among all neonates with maternal group B streptococcus carriage was 0.22% (231/104,196). Neonates whose mothers received second-line intrapartum antibiotics and no antibiotics had a higher risk for group B streptococcus early-onset sepsis infection than those whose mothers received first-line intrapartum antibiotics (adjusted odds ratio, 4.12; 95% confidence interval, 2.66-6.38 and adjusted odds ratio, 3.80; 95% confidence interval, 2.66-5.44, respectively). There was no statistically significant difference in the risk for group B streptococcus early-onset sepsis among neonates born to mothers who received second-line vs no antibiotics (adjusted odds ratio, 0.92; 95% confidence interval, 0.64-1.33).

CONCLUSION

Neonates exposed to second-line maternal group B streptococcus prophylaxis had an increased risk for group B streptococcus early-onset sepsis when compared with those exposed to first-line maternal group B streptococcus prophylaxis. There was no statistically significant difference in group B streptococcus early-onset sepsis incidence between second-line antibiotic prophylaxis and no antibiotics in mothers with group B streptococcus carriage.

Burden of bacterial antimicrobial resistance in low-income and middle-income countries avertible by existing interventions: an evidence review and modelling analysis

National action plans enumerate many interventions as potential strategies to reduce the burden of bacterial antimicrobial resistance (AMR). However, knowledge of the benefits achievable by specific approaches is needed to inform policy making, especially in low-income and middle-income countries (LMICs) with substantial AMR burden and low health-care system capacity. In a modelling analysis, we estimated that improving infection prevention and control programmes in LMIC health-care settings could prevent at least 337 000 (95% CI 250 200-465 200) AMR-associated deaths annually. Ensuring universal access to high-quality water, sanitation, and hygiene services would prevent 247 800 (160 000-337 800) AMR-associated deaths and paediatric vaccines 181 500 (153 400-206 800) AMR-associated deaths, from both direct prevention of resistant infections and reductions in antibiotic consumption. These estimates translate to prevention of 7·8% (5·6-11·0) of all AMR-associated mortality in LMICs by infection prevention and control, 5·7% (3·7-8·0) by water, sanitation, and hygiene, and 4·2% (3·4-5·1) by vaccination interventions. Despite the continuing need for research and innovation to overcome limitations of existing approaches, our findings indicate that reducing global AMR burden by 10% by the year 2030 is achievable with existing interventions. Our results should guide investments in public health interventions with the greatest potential to reduce AMR burden.

Genomic insights into the diversity, virulence, and antimicrobial resistance of group B Streptococcus clinical isolates from Saudi Arabia

Introduction

Detailed assessment of the population structure of group B Streptococcus (GBS) among adults is still lacking in Saudi Arabia. Here we characterized a representative collection of isolates from colonized and infected adults.

Methods

GBS isolates (n=89) were sequenced by Illumina and screened for virulence and antimicrobial resistance determinants. Genetic diversity was assessed by single nucleotide polymorphisms and core-genome MLST analyses.

Results

Genome sequences revealed 28 sequence types (STs) and nine distinct serotypes, including uncommon serotypes VII and VIII. Majority of these STs (n=76) belonged to the human-associated clonal complexes (CCs) CC1 (33.71%), CC19 (25.84%), CC17 (11.24%), CC10/CC12 (7.87%), and CC452 (6.74%). Major CCs exhibited intra-lineage serotype diversity, except for the hypervirulent CC17, which exclusively expressed serotype III. Virulence profiling revealed that nearly all isolates (94.38%) carried at least one of the four alpha family protein genes (i.e., alphaC, alp1, alp2/3, and rib), and 92.13% expressed one of the two serine-rich repeat surface proteins Srr1 or Srr2. In addition, most isolates harbored the pilus island (PI)-2a alone (15.73%) or in combination with PI-1 (62.92%), and those carrying PI-2b alone (10.11%) belonged to CC17. Phylogenetic analysis grouped the sequenced isolates according to CCs and further subdivided them along with their serotypes. Overall, isolates across all CC1 phylogenetic clusters expressed Srr1 and carried the PI-1 and PI-2a loci, but differed in genes encoding the alpha-like proteins. CC19 clusters were dominated by the III/rib/srr1/PI-1+PI-2a (43.48%, 10/23) and V/alp1/srr1/PI-1+PI-2a (34.78%, 8/23) lineages, whereas most CC17 isolates (90%, 9/10) had the same III/rib/srr2/P1-2b genetic background. Interestingly, genes encoding the CC17-specific adhesins HvgA and Srr2 were detected in phylogenetically distant isolates belonging to ST1212, suggesting that other highly virulent strains might be circulating within the species. Resistance to macrolides and/or lincosamides across all major CCs (n=48) was associated with the acquisition of erm(B) (62.5%, 30/48), erm(A) (27.1%, 13/48), lsa(C) (8.3%, 4/48), and mef(A) (2.1%, 1/48) genes, whereas resistance to tetracycline was mainly mediated by presence of tet(M) (64.18%, 43/67) and tet(O) (20.9%, 14/67) alone or in combination (13.43%, 9/67).

Discussion

These findings underscore the necessity for more rigorous characterization of GBS isolates causing infections.

A Review of the Impact of Streptococcal Infections and Antimicrobial Resistance on Human Health

Streptococcus pneumoniae, Streptococcus pyogenes (GAS), and Streptococcus agalactiae (GBS) are bacteria that can cause a range of infections, some of them life-threatening. This review examines the spread of antibiotic resistance and its mechanisms against antibiotics for streptococcal infections. Data on high-level penicillin-resistant invasive pneumococci have been found in Brazil (42.8%) and Japan (77%). The resistance is caused by mutations in genes that encode penicillin-binding proteins. Similarly, GAS and GBS strains reported from Asia, the USA, and Africa have undergone similar transformations in PBPs. Resistance to major alternatives of penicillins, macrolides, and lincosamides has become widespread among pneumococci and streptococci, especially in Asia (70-95%). The combination of several emm types with erm(B) is associated with the development of high-level macrolide resistance in GAS. Major mechanisms are ribosomal target modifications encoded by erm genes, ribosomal alterations, and active efflux pumps that regulate antibiotic entry due to mefA/E and msrD genes. Tetracycline resistance for streptococci in different countries varied from 22.4% in the USA to 83.7/100% in China, due to tet genes. Combined tetracycline/macrolide resistance is usually linked with the insertion of ermB into the transposon carrying tetM. New quinolone resistance is increasing by between 11.5 and 47.9% in Asia and Europe. The mechanism of quinolone resistance is based on mutations in gyrA/B, determinants for DNA gyrase, or parC/E encoding topoisomerase IV. The results for antibiotic resistance are alarming, and urgently call for increased monitoring of this problem and precautionary measures for control to prevent the spread of resistant mutant strains.

Characterization of invasive Group B Streptococcus isolates from Western Australian infants, 2004-2020

Background. Invasive Group B Streptococcus (GBS; Streptococcus agalactiae) remains a leading cause of infant morbidity and mortality. Intrapartum antibiotic prophylaxis (IAP) has been implemented in many countries with a reduction in early-onset disease, but an effective vaccine may further reduce the disease burden. Candidate vaccines targeting capsular polysaccharides and surface proteins are now in clinical trials.Methods. Using whole-genome sequencing and phenotypic antimicrobial susceptibility testing, we characterized sterile-site GBS isolates recovered from Western Australian infants between 2004 and 2020. Characteristics were compared between three time periods: 2004-2008, 2009-2015 and 2016-2020.Results. A total of 135 isolates were identified. The proportion of serotype III (22.7 % in Period 1 to 47.9 % in Period 3, P=0.04) and clonal complex 17 (13.6-39.6 %, P=0.01) isolates increased over time. Overall coverage of vaccines currently being trialled was >95 %. No isolates were penicillin resistant (MIC>0.25 mg l-1), but 21.5 % of isolates had reduced penicillin susceptibility (MIC>0.12 mg l-1) and penicillin MIC increased significantly over time (P=0.04). Clindamycin resistance increased over time to 45.8 % in the latest period.Conclusions. Based on comprehensive characterization of invasive infant GBS in Western Australia, we found that coverage for leading capsular polysaccharide and surface protein vaccine candidates was high. The demonstrated changes in serotype and molecular type highlight the need for ongoing surveillance, particularly with regard to future GBS vaccination programmes. The reduced susceptibility to IAP agents over time should inform changes to antibiotic guidelines.

A Rare Case of Streptococcus agalactiae Ventriculitis and Endocarditis

Streptococcus agalactiae infection is typically seen in specific populations, including neonates, pregnant women, and the elderly. These patients have immature, lower, and waning immune systems, which makes them more susceptible to infections. Typical S. agalactiae infections manifest as cellulitis, bacteremia, endocarditis, meningitis, ventriculitis (a rare complication of meningitis), and osteomyelitis. In rare cases, a patient can present with two or more of these typical infection manifestations. The authors present a case of a 48-year-old female with a past medical history of hypothyroidism and chronic back pain who presented to the emergency department with altered mental status. The patient developed nausea and vomiting two days prior to presentation after a family gathering, followed by occipital headache and agitation. On arrival at the emergency department, the patient did not follow commands and was drowsy. The initial examination showed positive for Brudzinski and Kernig signs. The patient was tachycardic, tachypneic, and hypertensive. Initial computed tomography (CT) head without contrast was negative for any acute pathology. Neurology was consulted, and a bedside lumbar puncture was performed, which was significant for elevated opening pressure of 32 cm H2O. The patient was initially started on ceftriaxone, ampicillin, vancomycin, acyclovir, and dexamethasone. Magnetic resonance imaging (MRI) of the brain with and without contrast showed acute ventriculitis, mild leptomeningeal enhancement, and a right posterior corona radiata acute lacunar infarct. Meningitis panel, BioFire (BioFire Diagnostics, Salt Lake City, UT), was positive for S. agalactiae, and the patient was de-escalated to ceftriaxone. Cerebrospinal fluid and blood cultures returned positive for S. agalactiae. A transthoracic echocardiogram was negative for endocarditis, but a transesophageal echocardiogram was significant for a 0.7 × 0.4 cm mobile echodensity attached to the posterior leaflet of the mitral valve (P1/P2 scallop). Repeat blood cultures, additional cerebrospinal fluid analysis, and infectious workup remained negative. Cardiology was consulted and recommended medical treatment. The patient improved clinically, continued ceftriaxone, and was discharged to complete a total of six weeks of treatment with outpatient follow-up evaluations. This case depicts a rare presentation of endocarditis, meningitis, and ventriculitis S. agalactiae infection and the need for a definite treatment algorithm in the management of complicated conditions such as the one presented.

Use of Essential Oils to Counteract the Phenomena of Antimicrobial Resistance in Livestock Species

Antimicrobial resistance is an increasingly widespread phenomenon that is of particular concern because of the possible consequences in the years to come. The dynamics leading to the resistance of microbial strains are diverse, but certainly include the incorrect use of veterinary drugs both in terms of dosage and timing of administration. Moreover, the drug is often administered in the absence of a diagnosis. Many active ingredients in pharmaceutical formulations are, therefore, losing their efficacy. In this situation, it is imperative to seek alternative treatment solutions. Essential oils are mixtures of compounds with different pharmacological properties. They have been shown to possess the antibacterial, anti-parasitic, antiviral, and regulatory properties of numerous metabolic processes. The abundance of molecules they contain makes it difficult for treated microbial species to develop pharmacological resistance. Given their natural origin, they are environmentally friendly and show little or no toxicity to higher animals. There are several published studies on the use of essential oils as antimicrobials, but the present literature has not been adequately summarized in a manuscript. This review aims to shed light on the results achieved by the scientific community regarding the use of essential oils to treat the main agents of bacterial infection of veterinary interest in livestock. The Google Scholar, PubMed, SciELO, and SCOPUS databases were used for the search and selection of studies. The manuscript aims to lay the foundations for a new strategy of veterinary drug use that is more environmentally friendly and less prone to the emergence of drug resistance phenomena.

Oral Probiotic Supplementation in Pregnancy to Reduce Group B Streptococcus Colonisation (OPSiP trial): study protocol for a double-blind parallel group randomised placebo trial

INTRODUCTION

Group B streptococcus (GBS), or Streptococcus agalactiae, remains a leading cause of neonatal morbidity and mortality. Canadian guidelines advise universal maternal screening for GBS colonisation in pregnancy in conjunction with selective antibiotic therapy. This results in over 1000 pregnant individuals receiving antibiotic therapy to prevent one case of early-onset neonatal GBS disease, and over 20 000 pregnant individuals receiving antibiotic therapy to prevent one neonatal death. Given the growing concern regarding the risk of negative sequela from antibiotic exposure, it is vital that alternative approaches to reduce maternal GBS colonisation are explored.Preliminary studies suggest some probiotic strains could confer protection in pregnancy against GBS colonisation.

METHODS AND ANALYSIS

This double-blind parallel group randomised trial aims to recruit 450 pregnant participants in Vancouver, BC, Canada and will compare GBS colonisation rates in those who have received a daily oral dose of three strains of probiotics with those who have received a placebo. The primary outcome will be GBS colonisation status, measured using a vaginal/rectal swab obtained between 35 weeks' gestation and delivery. Secondary outcomes will include maternal antibiotic exposure and urogenital infections. Analysis will be on an intention-to-treat basis.

PATIENT OR PUBLIC INVOLVEMENT

There was no patient or public involvement in the design of the study protocol.

ETHICS AND DISSEMINATION

This study protocol received ethics approval from the University of British Columbia's Clinical Research Ethics Board, Dublin City University and Health Canada. Findings will be presented at research rounds, conferences and in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03407157.

Mortality and neurodevelopmental outcome after invasive group B streptococcal infection in infants

AIM

To assess case fatality rate (CFR), infant mortality, and long-term neurodevelopmental disorders (NDDs) after invasive group B streptococcal (GBS; Streptococcus agalactiae) infection in infants.

METHOD

Children born in Norway between 1996 and 2019 were included. Data on pregnancies/deliveries, GBS infection, NDDs, and causes of death were retrieved from five national registries. The exposure was culture-confirmed invasive GBS infection during infancy. Outcomes were mortality and NDDs, the latter at a mean age of 12 years 10 months.

RESULTS

Among 1 415 625 live-born children, 866 (87%) of 1007 infants diagnosed with GBS infection (prevalence 0.71 per 1000) were included. The CFR was 5.0% (n = 43). GBS infection was associated with higher infant mortality (relative risk 19.41; 95% confidence interval [CI] 14.79-25.36) than the general population. Among survivors, 169 (20.7%) children were diagnosed with any NDD (relative risk 3.49; 95% CI 3.05-3.98). In particular, GBS meningitis was associated with high risks of attention-deficit/hyperactivity disorder, cerebral palsy, epilepsy, hearing impairment, and pervasive and specific developmental disorder.

INTERPRETATION

The burden of invasive GBS infection during infancy is considerable and continues to affect children beyond infancy. These findings emphasize the need for new preventive strategies for disease reduction, and the need for survivors to be directly included into early detection pathways to access early intervention if required.

WHAT THIS PAPER ADDS

The burden of invasive group B streptococcal (GBS) infection in Norway is considerable. Of GBS infection survivors, 20.7% were diagnosed with neurodevelopmental disorders (NDDs) at mean age 12 years 10 months. Infants with GBS meningitis were more often diagnosed with NDDs. Absolute risks associated with GBS infections were highest for pervasive and specific developmental disorder, cerebral palsy, and attention-deficit/hyperactivity disorder.

Late-Onset Meningitis in a Preterm Infant Caused by Streptococcus gallolyticus Subsp. Pasteurianus in Saudi Arabia: A Case Report and Literature Review

This report describes the progression of meningitis in a 24-day-old preterm male infant infected with Streptococcus gallolyticus subsp. pasteurianus (SGSP) and its medical care, pathogen detection, antibiotic treatment, and monitoring, ultimately leading to a positive outcome of successful recovery. Neonatal meningitis (NM) is a serious and potentially life-threatening condition, particularly in immunocompromised preterm infants. This report from Saudi Arabia presents a rare case of late-onset neonatal meningitis caused by SGSP in a preterm male infant. The 24-day-old preterm neonate presented with fever, lethargy, poor feeding, and respiratory distress. SGSP was confirmed by cerebral spinal fluid analysis showing the presence of pleocytosis and a low glucose ratio. Prompt antibiotic therapy with intravenous Ampicillin and Cefotaxime led to decreased pleocytosis, and the infant was discharged after 21 days. This report highlights the importance of vigilance, diagnosis, and management of neonatal infections caused by uncommon pathogens such as SGSP. The rarity of SGSP-caused meningitis emphasizes the need to monitor pregnant women for potential transmission and to implement early diagnostic and management strategies. This case report also encompasses a review of recent globally reported cases of neonatal S. gallolyticus infection, highlighting the distinctiveness of this report as the first of its type in Saudi Arabia.

Molecular typing and antimicrobial resistance of group B Streptococcus clinical isolates in Saudi Arabia

OBJECTIVES

Group B Streptococcus (GBS) has emerged as an important cause of severe infections in adults. However, limited data are available regarding the epidemiology of GBS in Saudi Arabia.

METHODS

Isolates were collected over a period of eight months from colonized (n = 104) and infected adults (n = 95). Serotypes and virulence determinants were detected by polymerase chain reactions (PCRs). Genetic relatedness was assessed using Multiple Locus Variable Number Tandem Repeat Analysis (MLVA). Antimicrobial susceptibilities were determined by disk diffusion.

RESULTS

Serotypes III and V (25% each) were the most prevalent, followed by serotypes II (16.18%), Ia (13.24%), VI (9.31%), and Ib (8.82%), while five isolates remained non-typeable (2.45%). Hypervirulent serotype III/CC17 clone (n = 21) accounted for 41.18% of the serotype III isolates. Most isolates (53.92%) harboured pilus island (PI) 1 and 2a types, while PI-2b was predominantly detected in the hypervirulent clone. Isolates were variably resistant to tetracycline (76.47%), erythromycin (36.76%), clindamycin (25.49%), and levofloxacin (6.37%), but remained susceptible to penicillin. Macrolide resistant isolates exhibited constitutive (55.42%) and inducible macrolide-lincosamide-streptogramin B resistance phenotypes (33.74%), while a few had L (9.64%) or M (1.2%) phenotypes. MLVA patterns of dominant serotypes III and V revealed 40 different types divided into 12 clusters and 28 singletons. Interestingly, macrolide resistance was significantly associated with two major MLVA types.

CONCLUSIONS

GBS isolates belonged predominantly to serotypes III and V, but there were no clear associations between serotypes and patient groups. The studied isolates exhibited high levels of resistance to erythromycin and clindamycin that need further surveillance.

Fructose promotes ampicillin killing of antibiotic-resistant Streptococcus agalactiae

Streptococcus agalactiae (GBS) is an important pathogenic bacteria that infected both aquatic animals and human beings, causing huge economic loss. The increasing cases of antibiotic-resistant GBS impose challenges to treat such infection by antibiotics. Thus, it is highly demanded for the approach to tackle antibiotic resistance in GBS. In this study, we adopt a metabolomic approach to identify the metabolic signature of ampicillin-resistant GBS (AR-GBS) that ampicillin is the routine choice to treat infection by GBS. We find glycolysis is significantly repressed in AR-GBS, and fructose is the crucial biomarker. Exogenous fructose not only reverses ampicillin resistance in AR-GBS but also in clinic isolates including methicillin-resistant Staphylococcus aureus (MRSA) and NDM-1 expressing Escherichia coli. The synergistic effect is confirmed in a zebrafish infection model. Furthermore, we demonstrate that the potentiation by fructose is dependent on glycolysis that enhances ampicillin uptake and the expression of penicillin-binding proteins, the ampicillin target. Our study demonstrates a novel approach to combat antibiotic resistance in GBS.

Discovery of novel phenanthridone derivatives with anti-streptococcal activity

To address the growing health threat posed by drug-resistant pathogenic microorganisms, the development of novel antimicrobial medications with multiple mechanisms of action is in urgent demand. With traditional antibacterial drug resources challenging to push forward, developing new antibacterial drugs has become a hot spot in biomedical research. In this study, we tested the antibacterial activity of 119 phenanthridine derivatives via the antibacterial assay and obtained 5 candidates. The cytotoxicity assay showed one phenanthridine derivative, HCK20, was safe for mammalian cells below 125 µM. HCK20 was verified to possess significant antibacterial activity to Streptococcus spp., such as Streptococcus pneumoniae, Streptococcus agalactiae, Streptococcus suis, Streptococcus dysgalactiae, and Streptococcus equi with MICs ranging from 15 to 60 µM. Furthermore, we found that HCK20 probably achieved its bacterial inhibition by influencing the permeability of bacterial cell walls via interacting with Streptococcal penicillin-binding proteins (PBPs). Our results suggest that this phenanthridine derivative, HCK20, has great potential to become a novel antibacterial agent that can be a potent treatment for streptococcal infections.

Vaccine value profile for Group B streptococcus

Group B streptococcus (GBS) is a major global cause of neonatal meningitis, sepsis and pneumonia, with an estimated 91,000 infant deaths per year and an additional 46,000 stillbirths. GBS infection in pregnancy is also associated with adverse maternal outcomes and preterm births. As such, the World Health Organization (WHO) prioritised the development of a GBS vaccine suitable for use in pregnant women and use in LMICs, where the burden of disease is highest. Several GBS vaccines are in clinical development. The WHO Defeating Meningitis by 2030 has set a target of 2026 for vaccine licensure. This 'Vaccine Value Profile' (VVP) for GBS is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. 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 regions of AFR, AMR, EUR, WPR. All contributors have extensive expertise on various elements of the GBS VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Genomic Analysis of Group B Streptococcus Carriage Isolates From Botswana Reveals Distinct Local Epidemiology and Identifies Novel Strains

In pregnant people colonized with group B Streptococcus (GBS) in Botswana, we report the presence/expansion of sequence types 223 and 109, a low rate of erythromycin resistance, and 3 novel sequence types. These data highlight the importance of local epidemiologic studies of GBS, a significant source of neonatal disease.

CD1 and iNKT cells mediate immune responses against the GBS hemolytic lipid toxin induced by a non-toxic analog

Although hemolytic lipids have been discovered from many human pathogens including Group B Streptococcus (GBS), strategies that neutralize their function are lacking. GBS is a leading cause of pregnancy-associated neonatal infections, and adult GBS infections are on the rise. The GBS hemolytic lipid toxin or granadaene, is cytotoxic to many immune cells including T and B cells. We previously showed that mice immunized with a synthetic nontoxic analog of granadaene known as R-P4 had reduced bacterial dissemination during systemic infection. However, mechanisms important for R-P4 mediated immune protection was not understood. Here, we show that immune serum from R-P4-immunized mice facilitate GBS opsonophagocytic killing and protect naïve mice from GBS infection. Further, CD4+ T cells isolated from R-P4-immunized mice proliferated in response to R-P4 stimulation in a CD1d- and iNKT cell-dependent manner. Consistent with these observations, R-P4 immunized mice lacking CD1d or CD1d-restricted iNKT cells exhibit elevated bacterial burden. Additionally, adoptive transfer of iNKT cells from R-P4 vaccinated mice significantly reduced GBS dissemination compared to adjuvant controls. Finally, maternal R-P4 vaccination provided protection against ascending GBS infection during pregnancy. These findings are relevant in the development of therapeutic strategies targeting lipid cytotoxins.

Molecular characterisation and antimicrobial resistance of Streptococcus agalactiae isolates from dairy farms in China

Introduction

Streptococcus agalactiae (S. agalactiae) is a pathogen causing bovine mastitis that results in considerable economic losses in the livestock sector. To understand the distribution and drug resistance characteristics of S. agalactiae from dairy cow mastitis cases in China, multilocus sequence typing (MLST) was carried out and the serotypes and drug resistance characteristics of the bacteria in the region were analysed.

Material and Methods

A total of 21 strains of bovine S. agalactiae were characterised based on MLST, molecular serotyping, antimicrobial susceptibility testing, and the presence of drug resistance genes.

Results

The serotypes were mainly Ia and II, accounting for 47.6% and 42.9% of all serotypes, respectively. Five sequence types (STs) were identified through MLST. The ST103 and ST1878 strains were predominant, with rates of 52.4% and 28.6%, respectively. The latter is a novel, previously uncharacterised sequence type. More than 90% of S. agalactiae strains were susceptible to penicillin, oxacillin, cephalothin, ceftiofur, gentamicin, florfenicol and sulfamethoxazole. The bacteria showed high resistance to tetracycline (85.7%), clindamycin (52.1%) and erythromycin (47.6%). Resistant genes were detected by PCR, the result of which showed that 47.6%, 33.3% and 38.1% of isolates carried the tet(M), tet(O) and erm(B) genes, respectively.

Conclusion

The results of this study indicate that S. agalactiae show a high level of antimicrobial resistance. It is necessary to monitor the pathogens of mastitis to prevent the transmission of these bacteria.

Genomic characterization of emerging invasive Streptococcus agalactiae serotype VIII in Alberta, Canada

Invasive Group B Streptococcus (GBS) can infect pregnant women, neonates, and older adults. Invasive GBS serotype VIII is infrequent in Alberta; however, cases have increased in recent years. Here, genomic analysis was used to characterize fourteen adult invasive serotype VIII isolates from 2009 to 2021. Trends in descriptive clinical data and antimicrobial susceptibility results were evaluated for invasive serotype VIII isolates from Alberta. Isolate genomes were sequenced and subjected to molecular sequence typing, virulence and antimicrobial resistance gene identification, phylogenetic analysis, and pangenome determination. Multilocus sequencing typing identified eight ST42 (Clonal Complex; CC19), four ST1 (CC1), and two ST2 (CC1) profiles. Isolates were susceptible to penicillin, erythromycin, chloramphenicol, and clindamycin, apart from one isolate that displayed erythromycin and inducible clindamycin resistance. All isolates carried genes for peptide antibiotic resistance, three isolates for tetracycline resistance, and one for macrolide, lincosamide, and streptogramin resistance. All genomes carried targets currently being considered for protein-based vaccines (e.g., pili and/or Alpha family proteins). Overall, invasive GBS serotype VIII is emerging in Alberta, primarily due to ST42. Characterization and continued surveillance of serotype VIII will be important for outbreak prevention, informing vaccine development, and contributing to our understanding of the global epidemiology of this rare serotype.

A review of penicillin binding protein and group A Streptococcus with reduced-β-lactam susceptibility

With the widespread use of antibiotics, antimicrobial resistance (AMR) has become a global problem that endangers public health. Despite the global high prevalence of group A Streptococcus (GAS) infections and the global widespread use of β-lactams, β-lactams remain the first-line treatment option for GAS infection. β-hemolytic streptococci maintain a persistent susceptibility to β-lactams, which is an extremely special phenomenon in the genus Streptococci, while the exact current mechanism is not known. In recent years, several studies have found that the gene encoding penicillin binding protein 2X (pbp2x) is associated with GAS with reduced-β-lactam susceptibility. The purpose of this review is to summarize the current published data on GAS penicillin binding proteins and β-lactam susceptibility, to explore the relationship between them, and to be alert to the emergence of GAS with reduced susceptibility to β-lactams.

Safety and immunogenicity of the group B streptococcus vaccine AlpN in a placebo-controlled double-blind phase 1 trial

Group B streptococcus (GBS) is a leading cause of life-threatening neonatal infections and subsets of adverse pregnancy outcomes. Essentially all GBS strains possess one allele of the alpha-like protein (Alp) family. A maternal GBS vaccine, consisting of the fused N-terminal domains of the Alps αC and Rib (GBS-NN), was recently demonstrated to be safe and immunogenic in healthy adult women. To enhance antibody responses to all clinically relevant Alps, a second-generation vaccine has been developed (AlpN), also containing the N-terminal domain of Alp1 and the one shared by Alp2 and Alp3. In this study, the safety and immunogenicity of AlpN is assessed in a randomized, double-blind, placebo-controlled, and parallel-group phase I study, involving 60 healthy non-pregnant women. AlpN is well tolerated and elicits similarly robust and persistent antibody responses against all four Alp-N-terminal domains, resulting in enhanced opsonophagocytic killing of all Alp serotypes covered by the vaccine.

Genomic Analysis Reveals New Integrative Conjugal Elements and Transposons in GBS Conferring Antimicrobial Resistance

Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of neonatal sepsis and increasingly found as an invasive pathogen in older patient populations. Beta-lactam antibiotics remain the most effective therapeutic with resistance rarely reported, while the majority of GBS isolates carry the tetracycline resistance gene tet(M) in fixed genomic positions amongst five predominant clonal clades. In the UK, GBS resistance to clindamycin and erythromycin has increased from 3% in 1991 to 11.9% (clindamycin) and 20.2% (erythromycin), as reported in this study. Here, a systematic investigation of antimicrobial resistance genomic content sought to fully characterise the associated mobile genetic elements within phenotypically resistant GBS isolates from 193 invasive and non-invasive infections of UK adult patients collected during 2014 and 2015. Resistance to erythromycin and clindamycin was mediated by erm(A) (16/193, 8.2%), erm(B) (16/193, 8.2%), mef(A)/msr(D) (10/193, 5.1%), lsa(C) (3/193, 1.5%), lnu(C) (1/193, 0.5%), and erm(T) (1/193, 0.5%) genes. The integrative conjugative elements (ICEs) carrying these genes were occasionally found in combination with high gentamicin resistance mediating genes aac(6')-aph(2″), aminoglycoside resistance genes (ant(6-Ia), aph(3'-III), and/or aad(E)), alternative tetracycline resistance genes (tet(O) and tet(S)), and/or chloramphenicol resistance gene cat(Q), mediating resistance to multiple classes of antibiotics. This study provides evidence of the retention of previously reported ICESag37 (n = 4), ICESag236 (n = 2), and ICESpy009 (n = 3), as well as the definition of sixteen novel ICEs and three novel transposons within the GBS lineage, with no evidence of horizontal transfer.

Prevalence of Group B Streptococcus maternal colonization, serotype distribution, and antimicrobial resistance in Sub-Saharan Africa: A systematic review and meta-analysis

OBJECTIVE

Group B Streptococcus (GBS)-associated maternal, perinatal, and neonatal mortality and morbidity disproportionately affects Sub-Saharan Africa (SSA). This systematic review and meta-analysis aimed to address the estimated prevalence, antimicrobial susceptibility, and serotype distribution of GBS isolates in SSA.

METHODS

This study was done according to PRISMA guidelines. MEDLINE/PubMed, CINAHL (EBSCO), Embase, SCOPUS, Web of Sciences databases, and Google Scholar were used to retrieve both published and unpublished articles. STATA software version 17 was used for data analysis. Forest plots using the random-effect model were used to present the findings. Heterogeneity was assessed using Cochrane chi-square (I²) statistics, while the Egger intercept was used to assess publication bias.

RESULTS

Fifty-eight studies that fulfilled the eligibility criteria were included for meta-analysis. The pooled prevalence of maternal rectovaginal colonization and vertical transmission of GBS were 16.06, 95% CI [13.94, 18.30] and 43.31%, 95% CI [30.75, 56.32], respectively. The highest pooled proportion of antibiotic resistance to GBS was observed in gentamicin (45.58%, 95% CI [4.12%, 91.23]), followed by erythromycin, (25.11%, 95% CI [16.70, 34.49]). The lowest antibiotic resistance was observed in vancomycin (3.84%, 95% CI [0.48, 9.22]). Our findings indicate that serotypes Ia/Ib/II/ III/and V cover almost 88.6% of serotypes in SSA.

CONCLUSIONS

The estimated high prevalence and resistance to different antibiotic classes observed in GBS isolates from SSA suggests the need for implementation of effective intervention efforts.

Molecular Epidemiology of Group B Streptococcus Isolates from Pregnant Women with Premature Rupture of Membranes in Fuzhou, China

Objective

This study investigated the molecular epidemiology of Group B Streptococcus (GBS) in pregnant women with premature rupture of membranes (PROM) in Fuzhou region of China as a source of clinical reference.

Methods

GBS isolates were obtained from pregnant women with PROM. All isolates were genotyped, serotyped, and tested for drug-resistance and virulence genes using PCR and DNA sequencing. Antibiotic susceptibility testing was performed using the Vitek^® 2 automated system.

Results

Among the 140 GBS isolates, seventeen sequence types (STs) were identified, of which ST19 (20.0%) was the most prevalent, followed by ST862, ST10, and ST12. Three clonal complexes (CC19, CC10 and CC1) were identified. The predominant serotype was III (45.7%), followed by V (23.6%), Ib (18.6%), Ia (7.1%), and II (3.6%). The prevalence of multidrug resistance was 72.8% (102/140). All isolates were susceptible to penicillin G, ampicillin, quinupristin, linezolid, vancomycin, and tigecycline. The majority of isolates were resistant to erythromycin (70.0%), clindamycin (72.1%), and tetracycline (81.4%), and 28.6% of isolates were resistant to levofloxacin and moxifloxacin. Of the 98 erythromycin-resistant strains, mreA, ermB, mefA, mefE, ermA, and ermTR were detected in 100%, 70.4%, 49.0%, 22.4%, 13.3%, and 9.2%, respectively. No linB was detected among 101 clindamycin-resistant strains. Of the 114 tetracycline-resistant strains, tetM, tetK, tetL and tetO were detected in 52.6%, 61.4%, 7.9%, and 23.7%, respectively. Regarding virulence genes, all strains carried rib and hylB, followed by scpB (98.6%), and bca (80.7%), whereas only one strain carried bac.

Conclusion

ST19/III and ST862/III were the most prevalent GBS subtypes. Penicillin G remains a first-line antibiotic for intrapartum antibiotic prophylaxis and treatment of GBS infections. The prevalence of resistance to clindamycin, erythromycin, and tetracycline is high among GBS isolates in the Fuzhou region. ST862 and ST651 are emerging animal origin STs in human infections, and may become potential zoonotic threats.

Maternal colonization with group B Streptococcus and antibiotic resistance in China: systematic review and meta-analyses

BACKGROUND

Maternal rectovaginal colonization with group B Streptococcus (GBS) or Streptococcus agalactiae is the most common pathway for this disease during the perinatal period. This meta-analysis aimed to summarize existing data regarding maternal colonization, serotype profiles, and antibiotic resistance in China.

METHODS

Systematic literature reviews were conducted after searching 6 databases. Meta-analysis was applied to analyze colonization rate, serotype, and antimicrobial susceptibility of GBS clinical isolates in different regions of China. Summary estimates are presented using tables, funnel plots, forest plots, histograms, violin plots, and line plots.

RESULTS

The dataset regarding colonization included 52 articles and 195 303 pregnant women. Our estimate for maternal GBS colonization in China was 8.1% (95% confidence interval [CI] 7.2%-8.9%). Serotypes Ia, Ib, III, and V account for 95.9% of identified isolates. Serotype III, which is frequently associated with the hypervirulent clonal complex, accounts for 46.4%. Among the maternal GBS isolates using multilocus sequence typing (MLST), ST19 (25.7%, 289/1126) and ST10 (25.1%, 283/1126) were most common, followed by ST12 (12.4%, 140/1126), ST17 (4.8%, 54/1126), and ST651 (3.7%, 42/1126). GBS was highly resistant to tetracycline (75.1% [95% CI 74.0-76.3%]) and erythromycin (65.4% [95% CI 64.5-66.3%]) and generally susceptible to penicillin, ampicillin, vancomycin, ceftriaxone, and linezolid. Resistance rates of GBS to clindamycin and levofloxacin varied greatly (1.0-99.2% and 10.3-72.9%, respectively). A summary analysis of the bacterial drug resistance reports released by the China Antimicrobial Resistance Surveillance System (CARSS) in the past 5 years showed that the drug resistance rate of GBS to erythromycin, clindamycin, and levofloxacin decreased slowly from 2018 to 2020. However, the resistance rates of GBS to all 3 antibiotics increased slightly in 2021.

CONCLUSIONS

The overall colonization rate in China was much lower than the global colonization rate (17.4%). Consistent with many original and review reports in other parts of the world, GBS was highly resistant to tetracycline. However, the resistance of GBS isolates in China to erythromycin and clindamycin was greater than in other countries. This paper provides important epidemiological information, to assist with prevention and treatment of GBS colonization in these women.

Molecular characteristics and antibiotic resistance mechanisms of clindamycin-resistant Streptococcus agalactiae isolates in China

Streptococcus agalactiae (Group B Streptococcus, GBS) is a major cause of neonatal infections with high morbidity and mortality, and clindamycin is the main antibiotic used to treat GBS infections in patients allergic to penicillin. We aimed to analyse the antibiotic sensitivity, sequence types, serotypes, virulence factors, and antibiotic resistance mechanisms of clinically isolated clindamycin-resistant S. agalactiae and provide basic data for the treatment, prevention, and control of clinical infection of S. agalactiae. A total of 110 strains of clindamycin-resistant S. agalactiae were collected from two tertiary hospitals in Hebei, China. We performed antibiotic sensitivity tests for 11 antibiotics on these strains and whole-genome sequencing analysis. All the strains were susceptible to penicillin, ampicillin, linezolid, vancomycin, tigecycline, and quinupristin-dalfopristin. Resistance to erythromycin, levofloxacin, tetracycline, and chloramphenicol were also observed. Genome sequence analysis revealed that all strains belonged to 12 sequence types (STs) related to six cloning complexes (CCs), namely CC10, CC19, CC23, CC651, CC1, and CC17. Five serotypes were identified, including IA, IB, II, III, and V. The most prominent resistance genes were mreA (100%) and ermB (81.8%). Furthermore, cfb, cylE, pavA and the gene cluster related to the pili were 100% present in all strains, followed by lmb (95.5%) and srr1 (67.2%). This study found that clindamycin-resistant S. agalactiae showed polymorphisms in molecular types and serotypes. Furthermore, multiple virulence factor genes have been identified in their genomes.

Advances towards licensure of a maternal vaccine for the prevention of invasive group B streptococcus disease in infants: a discussion of different approaches

Group B streptococcus (Streptococcus agalactiae, GBS) is an important cause of life-threatening disease in newborns. Pregnant women colonized with GBS can transmit the bacteria to the developing fetus, as well as to their neonates during or after delivery where infection can lead to sepsis, meningitis, pneumonia, or/and death. While intrapartum antibiotic prophylaxis (IAP) is the standard of care for prevention of invasive GBS disease in some countries, even in such settings a substantial residual burden of disease remains. A GBS vaccine administered during pregnancy could potentially address this important unmet medical need and provide an adjunct or alternative to IAP for the prevention of invasive GBS disease in neonates. A hurdle for vaccine development has been relatively low disease rates making efficacy studies difficult. Given the well-accepted inverse relationship between anti-GBS capsular polysaccharide antibody titers at birth and risk of disease, licensure using serological criteria as a surrogate biomarker represents a promising approach to accelerate the availability of a GBS vaccine.

Neonatal invasive disease caused by Streptococcus agalactiae in Europe: the DEVANI multi-center study

PURPOSE

Group B streptococcus (GBS) remains a leading cause of invasive disease, mainly sepsis and meningitis, in infants < 3 months of age and of mortality among neonates. This study, a major component of the European DEVANI project (Design of a Vaccine Against Neonatal Infections) describes clinical and important microbiological characteristics of neonatal GBS diseases. It quantifies the rate of antenatal screening and intrapartum antibiotic prophylaxis among cases and identifies risk factors associated with an adverse outcome.

METHODS

Clinical and microbiological data from 153 invasive neonatal cases (82 early-onset [EOD], 71 late-onset disease [LOD] cases) were collected in eight European countries from mid-2008 to end-2010.

RESULTS

Respiratory distress was the most frequent clinical sign at onset of EOD, while meningitis is found in > 30% of LOD. The study revealed that 59% of mothers of EOD cases had not received antenatal screening, whilst GBS was detected in 48.5% of screened cases. Meningitis was associated with an adverse outcome in LOD cases, while prematurity and the presence of cardiocirculatory symptoms were associated with an adverse outcome in EOD cases. Capsular-polysaccharide type III was the most frequent in both EOD and LOD cases with regional differences in the clonal complex distribution.

CONCLUSIONS

Standardizing recommendations related to neonatal GBS disease and increasing compliance might improve clinical care and the prevention of GBS EOD. But even full adherence to antenatal screening would miss a relevant number of EOD cases, thus, the most promising prophylactic approach against GBS EOD and LOD would be a vaccine for maternal immunization.

Transmission of Group B Streptococcus in late-onset neonatal disease: a narrative review of current evidence

Group B streptococcus (GBS) late-onset disease (LOD, occurring from 7 through 89 days of life) is an important cause of sepsis and meningitis in infants. The pathogenesis and modes of transmission of LOD to neonates are yet to be elucidated. Established risk factors for the incidence of LOD include maternal GBS colonisation, young maternal age, preterm birth, HIV exposure and African ethnicity. The mucosal colonisation by GBS may be acquired perinatally or in the postpartum period from maternal or other sources. Growing evidence has demonstrated the predominant role of maternal sources in the transmission of LOD. Intrapartum antibiotic prophylaxis (IAP) to prevent early-onset disease reduces neonatal GBS colonisation during delivery; however, a significant proportion of IAP-exposed neonates born to GBS-carrier mothers acquire the pathogen at mucosal sites in the first weeks of life. GBS-infected breast milk, with or without presence of mastitis, is considered a potential vehicle for transmitting GBS. Furthermore, horizontal transmission is possible from nosocomial and other community sources. Although unfrequently reported, nosocomial transmission of GBS in the neonatal intensive care unit is probably less rare than is usually believed. GBS disease can sometime recur and is usually caused by the same GBS serotype that caused the primary infection. This review aims to discuss the dynamics of transmission of GBS in the neonatal LOD.

Genomic Analysis of Group B Streptococcus from Neonatal Sepsis Reveals Clonal CC17 Expansion and Virulence- and Resistance-Associated Traits After Intrapartum Antibiotic Prophylaxis

BACKGROUND

Group B Streptococcus (GBS) is a leading cause of invasive neonatal infections. This study aimed to investigate the trend of GBS serotype and genotype change and their correlation with antimicrobial resistance before and after implementation of intrapartum antibiotic prophylaxis (IAP).

METHODS

We performed serotyping, whole-genome sequencing, antimicrobial susceptibility testing, and single-nucleotide polymorphism (SNP)-based phylogenetic analysis on 238 invasive GBS isolates collected from October 1998 to February 2020 in Taiwan.

RESULTS

There were 7 serotypes and 6 clonal complexes (CCs) among the 238 GBS isolates, and more than half of the isolates carried multiple antimicrobial resistance genes. The expansion of CC17 strains and the increase in late-onset disease occurred synchronously after the implementation of IAP. Analysis of the carriage isolates from pregnant women showed diverse serotype distribution in the IAP era. The antimicrobial susceptibility testing showed that all 238 strains were susceptible to ampicillin and penicillin, while the number of various resistance genes in GBS genomes was found increased with the expansion of CC17. Compared with reference genomes, 697 nonsynonymous SNPs in 443 protein-coding genes were CC17 specific.

CONCLUSIONS

The study revealed the expansion of GBS CC17 and the increase of late-onset disease that occurred simultaneously with the implementation of IAP. Although the susceptibility of CC17 to antimicrobial agents is not different from that of other sequence types at present, GBS with phenotypic resistance to antimicrobials may emerge in the future, given the environmental selection pressure and the continued accumulation of SNP mutations.

Updates on Group B Streptococcus Infection in the Field of Obstetrics and Gynecology

Group B Streptococcus (GBS, Streptococcus agalactiae) is a Gram-positive bacterium that is commonly found in the gastrointestinal and urogenital tracts. However, its colonization during pregnancy is an important cause of maternal and neonatal morbidity and mortality worldwide. Herein, we specifically looked at GBS in relation to the field of Obstetrics (OB) along with the field of Gynecology (GY). In this review, based on the clinical significance of GBS in the field of OBGY, topics of how GBS is being detected, treated, and should be prevented are addressed.