Anovaginal Colonization by Group B Streptococcus and Streptococcus anginosus among Pregnant Women in Brazil and Its Association with Clinical Features

Streptococcus agalactiae (Group B Streptococcus; GBS) is a leading cause of neonatal invasive disease worldwide. GBS can colonize the human gastrointestinal and genitourinary tracts, and the anovaginal colonization of pregnant women is the main source for neonatal infection. Streptococcus anginosus, in turn, can colonize the human upper respiratory, gastrointestinal, and genitourinary tracts but has rarely been observed causing disease. However, in the last years, S. anginosus has been increasingly associated with human infections, mainly in the bloodstream and gastrointestinal and genitourinary tracts. Although anovaginal screening for GBS is common during pregnancy, data regarding the anovaginal colonization of pregnant women by S. anginosus are still scarce. Here, we show that during the assessment of anovaginal GBS colonization rates among pregnant women living in Rio de Janeiro, Brazil, S. anginosus was also commonly detected, and S. anginosus isolates presented a similar colony morphology and color pattern to GBS in chromogenic media. GBS was detected in 48 (12%) while S. anginosus was detected in 17 (4.3%) of the 399 anovaginal samples analyzed. The use of antibiotics during pregnancy and history of urinary tract infections and sexually transmitted infections were associated with the presence of S. anginosus. In turn, previous preterm birth was associated with the presence of GBS (p < 0.05). The correlation of GBS and S. anginosus with relevant clinical features of pregnant women in Rio de Janeiro, Brazil, highlights the need for the further investigation of these important bacteria in relation to this special population.

Changes in Group B Streptococcus Colonization among Pregnant Women before and after the Onset of the COVID-19 Pandemic in Brazil

Group B Streptococcus (GBS) is a leading cause of neonatal infections. The genitourinary and gastrointestinal tract of pregnant women are the main source of transmission to newborns. This work investigated the prevalence and characterized GBS from pregnant women in Rio de Janeiro, Brazil, comparing the periods before (January 2019 to March 2020; 521) and during (May 2020 to March 2021; 285) the COVID-19 pandemic. GBS was detected in 10.8% of anovaginal samples. Considering scenarios before and during the pandemic, GBS colonization rate significantly decreased (13.8% vs. 5.3%; p = 0.0001). No clinical and sociodemographic aspect was associated with GBS carriage (p > 0.05). A total of 80%, 13.8% and 4.6% GBS strains were non-susceptible to tetracycline, erythromycin and clindamycin, respectively. Serotype Ia was the most frequent (47.7%), followed by V (23.1%), II (18.4%), III (7.7%) and Ib (3.1%). An increasing trend of serotypes Ib and V, as well as of antimicrobial resistance rates, and a decreasing trend of serotypes II and III, were observed after the pandemic onset, albeit not statistically significant (p > 0.05). The reduction in GBS colonization rates and alterations in GBS serotypes and resistance profiles during the pandemic were not due to changes in the sociodemographic profile of the population. Considering that control and preventive measures related to the COVID-19 pandemic onset have impacted other infectious diseases, these results shed light on the need for the continuous surveillance of GBS among pregnant women in the post-pandemic era.

Influence of Penicillin on Biofilm Formation by Streptococcus agalactiae Serotype Ia/CC23

Streptococcus agalactiae (Group B Streptococcus , GBS) is a major agent of perinatal infections. Biofilms have been associated with GBS colonization and disease, as well as with infection persistence and recurrence. Although GBS remains susceptible to beta-lactams, it is still unknown how sessile cells respond to these antibiotics. Here, we evaluated the effect of different concentrations of penicillin (3-48 mg/L) on in vitro biofilm formation by four GBS strains belonging to serotype Ia/clonal complexes23 that were recovered from the oropharynx or urine of pregnant women and were previously characterized as strong biofilm producers. All four GBS strains were fully susceptible to penicillin (minimum inhibitory concentration = 0.023 mg/L), but penicillin was not able to fully prevent biofilm formation by these GBS strains. Biofilms formed in the presence of penicillin had reduced biomasses and thickness, but they were still classified as strong. Penicillin significantly reduced the density of live cells, but higher penicillin concentrations did not lead to improved prevention of biofilm formation. Biofilms formed in the presence of penicillin had no channels or long cocci chains observed in penicillin-free biofilms. Overall, results highlight the concerning possible impacts of biofilm formation in penicillin-based treatment and preventive strategies of GBS infections, even when the bacterial strain involved is fully antibiotic-susceptible.

Unusual finding of the human-adapted hypervirulent serotype III/ST17 clone in a historical bovine Group B Streptococcus isolate from Brazil

Group B Streptococcus (GBS) is a leading cause of human neonatal infections and bovine mastitis. We report here the unusual finding of the human-adapted hypervirulent serotype III/ST17 clone in a bovine GBS isolated in 1987 in Brazil. This isolate shared several phenotypic and genotypic characteristics with serotype III/ST17 strains obtained from human sources, including PFGE pattern, pilus genes, lactose fermentation, DNase activity, and antimicrobial susceptibility profile, highlighting the importance of continued tracking of GBS in the One Health scope. The study brings new evidence for the potential interspecies transmission and sheds new light into evolution aspects of the pathogen Group B Streptococcus (GBS) by reporting the occurrence of an ancient bovine GBS isolate belonging to a variant currently known to be exclusively found in human hosts.

Biofilm production and distribution of pilus variants among Streptococcus agalactiae isolated from human and animal sources

Streptococcus agalactiae (group B Streptococcus, GBS) is a major pathogen in humans and animals. Pili and biofilm may be important virulence factors in this bacterial species. Here, biofilm production and the distribution of pilus variants among 134 GBS isolates from human and animal sources were evaluated. Biofilm production was significantly enhanced in 1% glucose-supplemented medium (p < 0.05). Using this medium, most GBS strains were strong biofilm producers. Biomass was mainly composed of proteins, followed by extracellular DNA, while polysaccharides represented a minor portion. All GBS strains presented at least one pilus variant. PI-2a was the most common among human GBS while PI-2b was the most common among animal isolates. Human GBS harboring PI-2b and animal GBS harboring PI-2a presented significantly reduced biofilm production (p = 0.0033). In conclusion, strong biofilm production seems to be a common characteristic in GBS, and association of the clinical source with the pilus variant may be crucial for this.

DivulgaMicro : A Brazilian Initiative To Empower Early-Career Scientists with Science Communication Skills

Communication is fundamental in science. Among scientists, communication skills are required to write a comprehensible scientific manuscript or to prepare an attractive oral presentation. In addition, the ability to communicate successfully with the nonscientific community has been increasingly appreciated, as it represents the most effective way to promote popular scientific literacy. Nevertheless, students majoring in sciencerelated courses are not trained specifically for these purposes, and improving communication skills usually depends on tips and advice given by peers. To this end, we have launched DivulgaMicro, an initiative that aims to enhance science communication among early-career scientists in Brazil. DivulgaMicro relies on two major cornerstones: providing online resources via a dedicated website (www.divulgamicro.com.br/index.html) and promoting onsite workshops in universities located in different macro regions of the country. On the website, people can access a collection of fun activities designed to teach scientific concepts to a general audience, along with tips and news regarding public outreach events in Brazil. In the month following its launch, our website had 1,026 visitors from 10 different countries besides Brazil. Regarding the workshops, six were offered during 2018, with nearly 600 attendees. In the course, scientists are presented best practices for scientific writing and oral presentations, as well as techniques to improve communication with lay audiences, such as the use of storytelling structure and analogies. There is a high demand for science communication resources in Brazil, attesting to the importance of initiatives such as DivulgaMicro in our country.

Evolution of Penicillin Non-susceptibility Among Streptococcus pneumoniae Isolates Recovered From Asymptomatic Carriage and Invasive Disease Over 25 years in Brazil, 1990-2014

Streptococcus pneumoniae is a major cause of community-acquired pneumonia and meningitis, and it is also found as a commensal, colonizing the human upper respiratory tract of a portion of the human population. Its polysaccharide capsule allows the recognition of more than 90 capsular types and represents the target of the currently available pneumococcal conjugate vaccines (PCVs), such as the 10-valent (PCV10) and the 13-valent (PCV13). Penicillin non-susceptible pneumococci (PNSP) have been listed as one of the current major antimicrobial-resistant pathogen threats. In Brazil, the emergence of PNSP was initially detected in the mid 1990s and PCV10 has been part of the National Immunization Program since 2010. Here, we investigated the distribution of capsular types and penicillin susceptibility profiles of 783 pneumococcal strains isolated in Brazil between 1990 and 2014 to assess the evolution of penicillin non-susceptibility among pneumococci associated with asymptomatic carriage and invasive pneumococcal disease (IPD). The most common serotypes among carriage isolates were 19F, 6B, 6C, 23F, and 14. Among IPD isolates, the most frequent types were 14, 3, 6B, 5, 19F, and 4. We detected 21 types exclusively associated with IPD isolates, whereas non-typeable (NT) isolates were only detected in carriage. Nearly half of the isolates belonged to PCV10 serotypes, which remarkably decreased in occurrence (by nearly 50%) after PCV10 introduction (2011–2014), while non-PCV10 serotypes increased. PNSP frequency and levels were much higher among carriage isolates, but PNSP belonging to PCV10 serotypes were more common in IPD. While the occurrence of PNSP has decreased significantly among IPD isolates since 2011, it kept increasing among carriage strains. Such a difference can be attributed to the serotypes that emerged in each clinical source after PCV10 usage. PNSP with multidrug resistance profiles that emerged within carriage isolates comprised mostly serotypes 6C and 35B, as well as NT isolates. In turn, penicillin-susceptible capsular types 3, 20, and 8 have risen among IPD. Overall, our results reinforce the relevance of PNSP surveillance over a long period of time to better understand the dynamics of antimicrobial resistance in response to PCV introduction and may also contribute to improve control measures toward drug-resistant pneumococci.

Assessment of vaginal microbiota in Brazilian women with and without bacterial vaginosis and comparison with Nugent score

INTRODUCTION

Bacterial vaginosis (BV) is characterized by the depletion of Lactobacillus spp. population and increase of other species, especially Gardnerella vaginalis and Atopobium vaginae. This study aimed to investigate the vaginal microbiota structure of Brazilian women with and without BV according to Nugent Score and to assess the correlation among Nugent score and the quantification of BV-associated bacteria.

METHODOLOGY

Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) assay was employed to characterize the vaginal microbiota structure. Quantification of Lactobacillus spp., G. vaginalis, A. vaginae, Mobiluncus sp. and M. hominis were determined by quantitative real-time PCR (qPCR).

RESULTS

Clustering by PCR-DGGE revealed differences in microbial structure of the different patient groups. Gardnerella vaginalis, A. vaginae, M. hominis and Mobiluncus sp. were detected at high loads in BV-associated microbiota. Quantification of Lactobacillus spp. showed an inverse correlation with Nugent score while the loads of G. vaginalis, A. vaginae, M. hominis and Mobiluncus sp. indicated a direct correlation with this method.

CONCLUSIONS

Despite Nugent score is considered the gold standard for BV diagnosis, qPCR stands out as a useful tool for bacteria quantification and an alternative for BV diagnosis. Vaginal microbiota is a complex microbial community although there is a common core among BV and non-BV women. Investigation of vaginal microbiota structure may contribute to the development of tools for diagnosis improvement and therapeutic regimen optimization.

Elevated α-synuclein caused by SNCA gene triplication impairs neuronal differentiation and maturation in Parkinson's patient-derived induced pluripotent stem cells

We have assessed the impact of α-synuclein overexpression on the differentiation potential and phenotypic signatures of two neural-committed induced pluripotent stem cell lines derived from a Parkinson's disease patient with a triplication of the human SNCA genomic locus. In parallel, comparative studies were performed on two control lines derived from healthy individuals and lines generated from the patient iPS-derived neuroprogenitor lines infected with a lentivirus incorporating a small hairpin RNA to knock down the SNCA mRNA. The SNCA triplication lines exhibited a reduced capacity to differentiate into dopaminergic or GABAergic neurons and decreased neurite outgrowth and lower neuronal activity compared with control cultures. This delayed maturation phenotype was confirmed by gene expression profiling, which revealed a significant reduction in mRNA for genes implicated in neuronal differentiation such as delta-like homolog 1 (DLK1), gamma-aminobutyric acid type B receptor subunit 2 (GABABR2), nuclear receptor related 1 protein (NURR1), G-protein-regulated inward-rectifier potassium channel 2 (GIRK-2) and tyrosine hydroxylase (TH). The differentiated patient cells also demonstrated increased autophagic flux when stressed with chloroquine. We conclude that a two-fold overexpression of α-synuclein caused by a triplication of the SNCA gene is sufficient to impair the differentiation of neuronal progenitor cells, a finding with implications for adult neurogenesis and Parkinson's disease progression, particularly in the context of bioenergetic dysfunction.