Molecular pathogenicity of Streptococcus anginosus

Streptococcus anginosus orchestrates antibacterial potential of NETs facilitating survival of accompanying pathogens

Streptococcus anginosus is considered an emerging opportunistic pathogen causing life-threatening infections, including abscesses and empyema. Noticeably, clinical data revealed that S. anginosus also constitutes an important component of polymicrobial infections. Here, we showed for the first time that S. anginosus inactivates the antibacterial potential of neutrophil extracellular traps (NETs). The process is determined by a cell wall-anchored nuclease referred to as SanA, which high expression dominates in clinical strains isolated from severe infections. Nuclease activity protects S. anginosus against the antibacterial activity of NETs, supporting at the same time the survival of coexisting highly pathogenic species of Enterobacteriales. Obtained data suggest that SanA nuclease should be recognized as a critical S. anginosus virulence factor determining severe monospecies purulent infections but also shielding other pathogens promoting the development of polymicrobial infections.

Surgically treated chronic maxillary sinusitis: Does the odontogenic etiology alone or in combination with a fungus ball matter?

PURPOSE

To determine whether odontogenic maxillary sinusitis, either alone (OMSw/oFB) or in combination with fungus ball (OMSwFB), is associated with specific clinical characteristics and treatment outcomes compared to non-odontogenic maxillary sinusitis.

MATERIALS AND METHODS

A retrospective cohort study was performed on patients who underwent surgical treatment for chronic maxillary sinusitis between 2013 and 2021. OMSw/oFB and OMSwFB patients, were selected as the study group, while patients diagnosed with non-odontogenic maxillary sinusitis (non-OMS) were enrolled as the control group. Predictor variables were OMSw/oFB and OMSwFB. Outcomes were clinical presentation, postoperative complications, and treatment outcome. Descriptive, bivariate, and multiple logistic regression statistics were calculated, and the significance level was set at P ≤ 0.05.

RESULTS

The sample included 200 patients with a mean age of 49.6 ± 20.1 years and 57.5 % were men. Of the 200 patients, 123 (61.5 %) had non-OMS, 55 (27.5 %) had OMSw/oFB, and 22 (11 %) had OMSwFB. Multivariate analysis showed that OMSw/oFB was associated with more successful treatment rates (OR = 8.19, p < 0.01), whereas OMSwFB was associated with a less favorable outcome (OR = 0.27, p = 0.03). Age was associated with an unfavorable outcome in both OMS groups (OR: 0.98, p = 0.03 and p = 0.03, respectively), but no significant associations with other outcomes were found.

CONCLUSION

This study suggests that OMSwFB is a recalcitrant form of OMS associated with a higher risk of persistent symptoms and less favorable outcome. These patients should be informed about the challenging nature of the disease and closely monitored.

A shared group of bacterial taxa in the duodenal microbiota of undernourished Pakistani children with environmental enteric dysfunction

Environmental enteric dysfunction (EED) is a subclinical syndrome of altered small intestinal function postulated to be an important contributor to childhood undernutrition. The role of small intestinal bacterial communities in the pathophysiology of EED is poorly defined due to a paucity of studies where there has been a direct collection of small intestinal samples from undernourished children. Sixty-three members of a Pakistani cohort identified as being acutely malnourished between 3 and 6 months of age and whose wasting (weight-for-length Z-score [WLZ]) failed to improve after a 2-month nutritional intervention underwent esophagogastroduodenoscopy (EGD). Paired duodenal luminal aspirates and duodenal mucosal biopsies were obtained from 43 children. Duodenal microbiota composition was characterized by sequencing bacterial 16S rRNA gene amplicons. Levels of bacterial taxa (amplicon sequence variants [ASVs]) were referenced to anthropometric indices, histopathologic severity in biopsies, expression of selected genes in the duodenal mucosa, and fecal levels of an immunoinflammatory biomarker (lipocalin-2). A "core" group of eight bacterial ASVs was present in the duodenal samples of 69% of participants. Streptococcus anginosus was the most prevalent, followed by Streptococcus sp., Gemella haemolysans, Streptococcus australis, Granulicatella elegans, Granulicatella adiacens, and Abiotrophia defectiva. At the time of EGD, none of the core taxa were significantly correlated with WLZ. Statistically significant correlations were documented between the abundances of Granulicatella elegans and Granulicatella adiacens and the expression of duodenal mucosal genes involved in immune responses (dual oxidase maturation factor 2, serum amyloid A, and granzyme H). These results suggest that a potential role for members of the oral microbiota in pathogenesis, notably Streptococcus, Gemella, and Granulicatella species, warrants further investigation.IMPORTANCEUndernutrition among women and children is a pressing global health problem. Environmental enteric dysfunction (EED) is a disease of the small intestine (SI) associated with impaired gut mucosal barrier function and reduced capacity for nutrient absorption. The cause of EED is ill-defined. One emerging hypothesis is that alterations in the SI microbiota contribute to EED. We performed a culture-independent analysis of the SI microbiota of a cohort of Pakistani children with undernutrition who had failed a standard nutritional intervention, underwent upper gastrointestinal tract endoscopy, and had histologic evidence of EED in their duodenal mucosal biopsies. The results revealed a shared group of bacterial taxa in their duodenums whose absolute abundances were correlated with levels of the expression of genes in the duodenal mucosa that are involved in inflammatory responses. A number of these bacterial taxa are more typically found in the oral microbiota, a finding that has potential physiologic and therapeutic implications.

Residents or Tourists: Is the Lactating Mammary Gland Colonized by Residential Microbiota?

The existence of the human milk microbiome has been widely recognized for almost two decades, with many studies examining its composition and relationship to maternal and infant health. However, the richness and viability of the human milk microbiota is surprisingly low. Given that the lactating mammary gland houses a warm and nutrient-rich environment and is in contact with the external environment, it may be expected that the lactating mammary gland would contain a high biomass microbiome. This discrepancy raises the question of whether the bacteria in milk come from true microbial colonization in the mammary gland ("residents") or are merely the result of constant influx from other bacterial sources ("tourists"). By drawing together data from animal, in vitro, and human studies, this review will examine the question of whether the lactating mammary gland is colonized by a residential microbiome.

Co-culturing with Streptococcus anginosus alters Staphylococcus aureus transcriptome when exposed to tonsillar cells

Introduction

Improved understanding of Staphylococcus aureus throat colonization in the presence of other co-existing microbes is important for mapping S. aureus adaptation to the human throat, and recurrence of infection. Here, we explore the responses triggered by the encounter between two common throat bacteria, S. aureus and Streptococcus anginosus, to identify genes in S. aureus that are important for colonization in the presence of human tonsillar epithelial cells and S. anginosus, and further compare this transcriptome with the genes expressed in S. aureus as only bacterium.

Methods

We performed an in vitro co-culture experiment followed by RNA sequencing to identify interaction-induced transcriptional alterations and differentially expressed genes (DEGs), followed by gene enrichment analysis.

Results and discussion

A total of 332 and 279 significantly differentially expressed genes with p-value < 0.05 and log2 FoldChange (log2FC) ≥ |2| were identified in S. aureus after 1 h and 3 h co-culturing, respectively. Alterations in expression of various S. aureus survival factors were observed when co-cultured with S. anginosus and tonsillar cells. The serine-aspartate repeat-containing protein D (sdrD) involved in adhesion, was for example highly upregulated in S. aureus during co-culturing with S. anginosus compared to S. aureus grown in the absence of S. anginosus, especially at 3 h. Several virulence genes encoding secreted proteins were also highly upregulated only when S. aureus was co-cultured with S. anginosus and tonsillar cells, and iron does not appear to be a limiting factor in this environment. These findings may be useful for the development of interventions against S. aureus throat colonization and could be further investigated to decipher the roles of the identified genes in the host immune response in context of a throat commensal landscape.

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.

Necrotizing fasciitis and fatal septic shock associated with Streptococcus constellatus

Streptococcus constellatus is usually a benign, commensal bacteria but has increased incidence in blood cultures and abscesses. This pathogenic involvement is most prevalent in individuals with underlying medical conditions, such as solid tumors and type 2 diabetes mellitus, as well as in cases of community-acquired infections. We report a 43-year-old male with a right medial thigh ulcer and necrotic scrotal skin. The wound culture from surgical debridement grew Streptococcus constellatus, and histology was consistent with stage III necrotizing fasciitis. Regardless of etiology, the mortality rate of patients with necrotizing fasciitis is greatly decreased with early intervention and thorough surgical debridement.

Clinical characteristics and mortality rates of bacteremia caused by Streptococcus anginosus group: A retrospective study of 84 cases at a tertiary hospital in South Korea

The Streptococcus anginosus group (SAG) is a subgroup of viridans streptococci comprising three species: S. anginosus, S. constellatus, and S. intermedius. SAG usually resides in the oral cavity and colonizes the throat, and the gastrointestinal and genitourinary tracts. SAG can form abscesses in various parts of the body; however, the clinical features of SAG infection are not clear. Here, we reviewed the medical records of all SAG bacteremia patients aged over 18 years who were diagnosed between January 2010 and December 2021 at a tertiary university hospital. We then compared clinical characteristics, source of infection, need for surgical or interventional treatment, and 28-day mortality rates among each species of SAG. Differences in percentages between groups were compared using a proportion test, and differences between mean values were assessed using the Kruskal-Wallis test with post-hoc Bonferroni correction. In total, 84 cases of SAG bacteremia (40 S. anginosus cases, 31 S. constellatus cases, and 13 S. intermedius cases) were identified. The most common comorbidity was diabetes mellitus (n = 26, 31%), and the most common source was hepatobiliary infection (n = 30, 35.7%). Polymicrobial bacteremia was observed in 22.6% (19/84) of cases. Twenty-eight day mortality due to S. anginosus bacteremia was 12.5%; no deaths were reported in the S. constellatus and S. intermedius groups. However, the difference among the groups was not significant (p = 0.054). Hepatobiliary infection was the most common source of SAG bacteremia. In addition, S. anginosus bacteremia resulted in more severe disease and higher mortality rates than S. constellatus or S. intermedius bacteremia.

Microbiota Diversity in Non-Small Cell Lung Cancer Gut and Mouth Cavity Microbiota Diversity in Non-Small Cell Lung Cancer Patients

Lung malignancies have a substantial impact on cancer incidence and mortality worldwide. Even though many factors involved in the development of the disease are known, many questions remain unanswered. Previous studies suggest that the intestinal microbiota may have a role in developing malignant diseases. According to some findings, the microbiota has proven to be a key modulator of carcinogenic processes and the immune response against cancer cells, potentially influencing the effectiveness of immunotherapy. In our study, we characterized culturable microorganisms associated with non-small cell lung cancer (NSCLC) that can be recovered from rectal swabs and mouthwash. In addition, we also explored differences in the culturable microbiota with two main types of NSCLC - adenocarcinoma (ADC) and squamous cell carcinoma (SCC). With 141 patients included in the study (86 ADC and 55 SCC cases), a significant difference was observed between the two types in seven bacterial species (Collinsella, Corynebacterium, Klebsiella, Lactobacillus, Neisseria, Rothia, and Streptococcus), including the site of origin. The relationship between microbial dysbiosis and lung cancer is poorly understood; future research could shed light on the links between gut microbiota and lung cancer development.

Oral microbiome of the inner surface of face masks and whole saliva during the COVID-19 pandemic

Wearing a face mask was strongly recommended during the COVID-19 pandemic. The purpose of this study was to investigate the diversity of the oral microbiome, the abundance of each bacterium on the inner surface of the mask, and the effects of xerostomia on the microbiota. The study was conducted on 55 generally healthy adults (45 women and 10 men, mean age 38.18 ± 12.49 years). Unstimulated flow rate (UFR) and stimulated flow rate (SFR) were measured in whole saliva samples collected for each condition. The 14 major oral bacterial species, including Porphyromonas gingivalis (P. gingivalis), Lactobacillus casei (L. casei), Tannerella forsythia (T. forsythia), and Treponema denticola (T. denticola) on the inner surface of the mask and in the UFR and SFR samples, were analyzed by real-time PCR. We found that the total DNA copy number of oral bacteria was significantly higher in UFR and SFR than in the mask (p < 0.001). On the inner surface of the mask, P. gingivalis and L. casei were the most abundant Gram-negative and Gram-positive species, respectively. The oral microbiome profile of the mask differed from that of the UFR and SFR samples. Shannon's diversity index was also significantly higher in the UFR and SFR than in the mask (2.64 ± 0.78, 2.66 ± 0.76, and 1.26 ± 1.51, respectively, p < 0.001). Shannon's diversity index of UFR and SFR had a significant positive correlation with each other (r = 0.828, p < 0.001), but there was no significant relationship with Shannon's diversity index of mask. Red complex abundance, including P. gingivalis, T. forsythia, and T. denticola, was significantly higher in UFR than in the mask. Interestingly, the DNA copy number of each of the 14 bacteria, the total bacterial amount, and Shannon's diversity index did not differ in the absence or presence of xerostomia (p > 0.05). In summary, oral bacteria migrated to and existed on the inside of the mask, and the presence of xerostomia did not affect the bacterial profiles. The inner surface of the mask had an independent oral microbiome profile, although this showed lower quantity and diversity than the UFR and SFR samples.

Studies of Streptococcus anginosus Virulence in Dictyostelium discoideum and Galleria mellonella Models

For many years, Streptococcus anginosus has been considered a commensal colonizing the oral cavity, as well as the gastrointestinal and genitourinary tracts. However, recent epidemiological and clinical data designate this bacterium as an emerging opportunistic pathogen. Despite the reported pathogenicity of S. anginosus, the molecular mechanism underpinning its virulence is poorly described. Therefore, our goal was to develop and optimize efficient and simple infection models that can be applied to examine the virulence of S. anginosus and to study host-pathogen interactions. Using 23 S. anginosus isolates collected from different infections, including severe and superficial infections, as well as an attenuated strain devoid of CppA, we demonstrate for the first time that Dictyostelium discoideum is a suitable model for initial, fast, and large-scale screening of virulence. Furthermore, we found that another nonvertebrate animal model, Galleria mellonella, can be used to study the pathogenesis of S. anginosus infection, with an emphasis on the interactions between the pathogen and host innate immunity. Examining the profile of immune defense genes, including antimicrobial peptides, opsonins, regulators of nodulation, and inhibitors of proteases, by quantitative PCR (qPCR) we identified different immune response profiles depending on the S. anginosus strain. Using these models, we show that S. anginosus is resistant to the bactericidal activity of phagocytes, a phenomenon confirmed using human neutrophils. Notably, since we found that the data from these models corresponded to the clinical severity of infection, we propose their further application to studies of the virulence of S. anginosus.

Streptococcus anginosus: a stealthy villain in deep odontogenic abscesses

Odontogenic infections (OIs) occasionally spread to deep facial and neck tissues. Our study aimed to explore the role of Streptococcus anginous group (SAG) in these severe OIs. A retrospective study of patients aged ≥ 18 years who required hospital care for acute OI was conducted. We analysed data of OI microbial samples and recorded findings of SAG and other pathogens. These findings were compared with data regarding patients' prehospital status and variables of infection severity. In total, 290 patients were included in the analyses. The most common (49%) bacterial finding was SAG. Other common findings were Streptococcus viridans and Prevotella species, Parvimonas micra, and Fusobacterium nucleatum. Infection severity variables were strongly associated with SAG occurrence. Treatment in an intensive care unit was significantly more common in patients with SAG than in patients without SAG (p < 0.001). In addition, SAG patients expressed higher levels of C-reactive protein (p = 0.001) and white blood cell counts (p < 0.001), and their hospital stays were longer than those of non-SAG patients (p = 0.001). SAG is a typical finding in severe OIs. Clinical features of SAG-related OIs are more challenging than in other OIs. Early detection of SAG, followed by comprehensive infection care with prompt and careful surgical treatment, is necessary due to the aggressive behaviour of this dangerous pathogen.

Cerebral abscesses with odontogenic origin: a population-based cohort study

Objectives

Recent studies have indicated that cerebral abscess (CA) patients with odontogenic origin are on the rise. However, CA patients are often poorly characterized and with an unknown etiologic background. The purpose of this study is to identify and characterize CA patients that may have an odontogenic origin based on microbiologic, radiographic, and/or clinical findings.

Materials and methods

This is a population-based cohort study analyzing retrospective and prospective data from CA patients. Radiographic examinations of panoramic radiographs (PRs) or computed tomography (CT) scans were conducted. CA patients characterized with odontogenic origin required the fulfilment of the following criteria on admission: (1) Oral pathologic conditions were the only bacterial infections present, (2) oral microorganisms were isolated in the purulent exudate from the brain, and (3) radiographically and/or clinical recordings of oral pathologic conditions.

Results

A total of 44 patients could be included in this study of which 25 (57%) were characterized as having CA with a likely odontogenic origin. Type two diabetes (T2D) (p = 0.014) and microorganisms of the Streptococcus anginosus group (SAG) (p < 0.01) were overrepresented in patients with CAs of odontogenic origin.

Conclusions

Odontogenic infections may cause CAs to a greater extent than previously assumed. T2D was overrepresented among patients with odontogenic CA. When microorganisms of the SAG were isolated from the brain pus, CA patients had a predisposing odontogenic or sinus infection.

Clinical relevance

The identification of patients with a likely odontogenic CA will contribute to understanding the etiology of the infectious disease and highlighting the importance of preserving oral health.

Using Microbiology Culture in Pediatric Appendicitis to Risk Stratify Patients: A Cohort Study

Background: We sought to investigate the value of intra-operative microbiology samples in pediatric appendicitis. Proposed benefits include tailoring post-operative antimicrobial management, risk-stratifying patients, and reducing post-operative intra-abdominal abscess formation. Patients and Methods: All cases of appendicitis managed with appendicectomy in a single center were collected from January 2015 to August 2020. Intra-operative microbiology samples were taken routinely. Post-operative outcomes were analyzed with reference to culture and sensitivity results. Histologic findings were further categorized as normal, simple, or complex. Results: Six hundred seventy-eight children had appendicectomies, and 608 had both microbiology and histology samples taken. Intra-abdominal fluid collection and subsequent intervention rates were 22% and 9%, respectively. There were more collections in those with a culture positive result (p < 0.001), and those growing each of three recognized organisms, Escherichia coli (p < 0.001), Pseudomonas aeruginosa (p = 0.01), and Streptococcus anginosus group (p < 0.001). Intervention rate was higher in the culture-positive result group (p = 0.002) and the Streptococcus anginosus group (p < 0.001). Conclusions: This study shows an increased risk of developing a collection with the isolation of one of three key organisms (Escherichia coli, Pseudomonas aeruginosa, Streptococcus anginosus group). Sersoal swabs are an effective and practical method of gathering information on organisms. Microbiologic yield was correlated to the severity of appendicitis. Isolation of Streptococcus anginosus increases the incidence of collections to 50%. This is useful to empower surgeons to prognosticate patients' potential outcomes based on both intra-operative, and microbiologic findings, and is useful in counseling patients and managing expectations. A prolonged course of antibiotic agents or higher dose may mitigate this risk.

Virulence factors of Streptococcus anginosus - a molecular perspective

Streptococcus anginosus together with S. constellatus and S. intermedius constitute the Streptococcus anginosus group (SAG), until recently considered to be benign commensals of the human mucosa isolated predominantly from oral cavity, but also from upper respiratory, intestinal, and urogenital tracts. For years the virulence potential of SAG was underestimated, mainly due to complications in correct species identification and their assignment to the physiological microbiota. Still, SAG representatives have been associated with purulent infections at oral and non-oral sites resulting in abscesses formation and empyema. Also, life threatening blood infections caused by SAG have been reported. However, the understanding of SAG as potential pathogen is only fragmentary, albeit certain aspects of SAG infection seem sufficiently well described to deserve a systematic overview. In this review we summarize the current state of knowledge of the S. anginosus pathogenicity factors and their mechanisms of action.

Multiple Hepatic Abscesses Secondary to Streptococcus anginosus Infection: A Case Report and Review of the Literature

Hepatic abscesses are rare and generally present as solitary lesions in immunocompromised patients. The development of multiple hepatic abscesses in an immunocompetent patient is relatively uncommon. We report a rare case of a 73-year-old woman who presented with fever and right upper quadrant abdominal tenderness. Laboratory findings were significant for leukocytosis, transaminitis, and elevated inflammatory markers. Peripheral blood culture grew Streptococcus anginosus. Computed tomography of the abdomen and pelvis (CT A/P) revealed multiple hypoattenuating ill-defined cystic lesions in the liver consistent with abscesses formation; this was confirmed by magnetic resonance cholangiopancreatography (MRCP). The patient underwent appropriate treatment with antibiotics. Upon a three-week follow-up, the patient’s symptoms subsided, and her laboratory parameters normalized. Although Streptococcus anginosus is a normal gastrointestinal flora, it has the potential to form abscesses. Our report indicates the importance of considering Streptococcus anginosus in the differential diagnosis. Management includes four to six weeks of antibiotic therapy together with drainage of larger abscesses.

The Clinical View on Streptococcus anginosus Group – Opportunistic Pathogens Coming Out of Hiding

Three distinct streptococcal species: Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus, belonging to the Streptococcus anginosus group (SAG), also known as Streptococcus milleri group, have been attracting clinicians and microbiologists, not only as oral commensals but also as opportunistic pathogens. For years they have been simply classified as so called viridans streptococci, and distinct species were not associated with particular clinical manifestations. Therefore, description of SAG members are clearly underrepresented in the literature, compared to other medically relevant streptococci. However, the increasing number of reports of life-threatening infections caused by SAG indicates their emerging pathogenicity. The improved clinical data generated with the application of modern molecular diagnostic techniques allow for precise identification of individual species belonging to SAG. This review summarizes clinical reports on SAG infections and systematizes data on the occurrence of individual species at the site of infection. We also discuss the issue of proper microbiological diagnostics, which is crucial for further clinical treatment.

The Role of SilX in Bacteriocin Production of Streptococcus anginosus

Streptococcus anginosus produces the novel antimicrobial peptide Angicin, which inhibits Gram positive microorganisms and is classified as a group IId bacteriocin. Production of Angicin is regulated by the quorum sensing system Sil (Streptococcus invasion locus), which is located adjacent to the bacteriocin gene cluster. Within this genetic region a typical CAAX protease is encoded, which was designated SilX. Nelfinavir, a HIV protease inhibitor, led to a concentration dependent reduction in antimicrobial activity, presumably through the inhibition of SilX. Concentrations exceeding 25 μM Nelfinavir caused a complete abolishment of bacteriocin activity against Listeria monocytogenes. These results are supported by the observation, that a SilX deletion mutant of S. anginosus strain BSU 1211 no longer inhibits the growth of L. monocytogenes. Antimicrobial activity could be restored by addition of synthetically synthesized mature SilCR, implying that SilX may be involved in the export and processing of the signal peptide SilCR. Some CAAX proteases have been reported to provide immunity against bacteriocins. However, in a radial diffusion assay the deletion mutant S. anginosus BSU 1211ΔSilX showed no sensitivity toward Angicin arguing against a role of SilX in the immunity of S. anginosus. The putative processing of the signal peptide SilCR indicates a novel function of the CAAX protease SilX, in the context of S. anginosus bacteriocin production.

Polymicrobial odontogenic periorbital and orbital necrotizing fasciitis (PONF): A case report

Purpose

To present a case of periorbital and orbital necrotizing fasciitis (PONF) from an odontogenic source with a distinct microbiologic profile and highlight the need for emergent multidisciplinary management.

Observations

A 39-year-old man presented with periorbital swelling, pain, and erythema following facial trauma. Imaging revealed peri-dental collections, accompanying maxillary sinusitis, and pre- and post-septal involvement. Immediate surgical debridement of necrotic tissue along with broad-spectrum antibiotics were pursued for management. Cultures grew multiple organisms, most notably Streptococcus milleri group and Staphylococcus lugdunensis.

Conclusions and Importance

PONF is a rare yet potentially fatal disease. Streptococcus milleri group and a fulminant course are to be suspected when the source is odontogenic. Timely multidisciplinary surgical debridement and medical management with intravenous antibiotics is critical for best outcomes.

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Odontogenic cases of periorbital and orbital necrotizing fasciitis (PONF) may have a fulminant course.

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Streptococcus milleri group is associated with odontogenic PONF.

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An emergent multi-disciplinary surgical and medical approach to PONF is highly recommended.

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Antibiotics may be optimized based on known virulence factors of suspected organisms.

Nature and Prevalence of Bacterial Taxa Persisting after Root Canal Chemomechanical Preparation in Permanent Teeth: A Systematic Review and Meta-analysis

INTRODUCTION

Culture-independent molecular studies have shown a broad spectrum of bacterial taxa that persist after chemomechanical procedures (CMP). Therefore, this study systematically reviewed these reports to explore the prevalence of bacteria in post-instrumentation samples of root canals from permanent teeth, especially of as-yet-uncultivated/difficult-to-culture bacteria.

METHODS

Electronic databases were searched from 2007 to January 2021. Clinical studies using culture-independent molecular methods to identify species-level taxa before and after CMP were included. Studies were critically appraised using the Joanna Briggs Institute Prevalence Critical Appraisal Checklist and the funnel plot analysis. The meta-analysis was performed on the prevalence of as-yet-uncultivated/difficult-to-culture bacterial taxa using RStudio.

RESULTS

A total of 3781 titles were screened, but only 20 studies were included. The most frequent species in post-instrumentation samples were Streptococcus spp., Leptotrichia buccalis, Fusobacterium nucleatum, and Capnocytophaga ochracea. The detection frequency of some species increased after CMP, including mainly Firmicutes members such as streptococci, Enterococcus faecium, Selenomonas noxia, and Solobacterium moorei. The prevalence (confidence interval) of difficult-to-culture species was as follows: Dialister invisus, 17% (7%-29%); Solobacterium moorei, 14% (8%-23%); Bacteroidaceae [G-1] bacterium HMT 272, 13% (5%-23%); and Filifactor alocis, 11% (3%-23%).

CONCLUSIONS

The prevalence of as-yet-uncultivated/difficult-to-culture bacterial taxa in post-instrumentation samples was low. The persistent species belonged mainly to the phylum Firmicutes, and streptococci were the major members. Future larger clinical studies on the composition of the whole bacterial community that persist after CMP are still necessary for a better understanding of bacterial interactions and their clinical significance in the treatment outcome.

Culture on Selective Media and Amplicon-Based Sequencing of 16S rRNA from Spontaneous Brain Abscess-the View from the Diagnostic Laboratory

Forty-one stored samples from cases of spontaneous brain abscess were investigated to gain insight into the natural history, causative agents, and relevant laboratory diagnostics of a rare infection. Samples from a larger collection were selected based on retrospective analysis of patient records. All samples were subjected to amplicon sequencing of 16S rRNA gene fragments. Supplementary culture on selected media was performed as suggested by bioinformatics analysis. For three cases, no microorganism was disclosed, while Toxoplasma gondii, Aspergillus fumigatus, and various bacteria were the cause of 1, 2, and 35 cases, respectively. Bacterial infections were monomicrobial in 20 cases and polymicrobial in 15; the microorganisms of the latter cases were restricted to residents of cavum oris. Amplicon sequencing did not further enhance the importance of the Streptococcus anginosus group, which was involved in 17 cases, and the single primer set used may be suboptimal for amplification of Actinomyces and Nocardia. But, amplicon-based sequencing unquestionably expanded the number of polybacterial infections, with focus on the Fusobacterium nucleatum group, Parvimonas, and Porphyromonas. Culture on selective media confirmed the presence of F. nucleatum group bacteria, which attained a prominence in spontaneous brain abscess similar to the S. anginosus group. Metagenomics is a powerful tool to disclose the spectrum of agents in polymicrobial infections, but a reliable cutoff value for substantial detection is complex. Commercial media for isolation of F. nucleatum group bacteria from mixed infections are available, and these pathogens should be carefully characterized. Isolation of Parvimonas and Porphyromonas in polymicrobial infections has not been resolved. IMPORTANCE Polymicrobial brain abscess is a challenge to the clinical microbiology laboratory due to the aggregative nature of the dental and oral microbiota. Because polymicrobial infections may escape detection by conventional culture methods, directed therapy toward a single detected bacterium is problematic. Amplicon-based sequencing provides important clues to these infections, but only cultured microorganisms can be fully characterized, subjected to antimicrobial susceptibility testing, and formally named. By use of specific selective culture plates, we successfully isolated bacteria of the Fusobacterium nucleatum group, and these bacteria rose to the same prominence as the widely recognized pathogen, the Streptococcus anginosus group. Named and unnamed members of the Fusobacterium nucleatum group must be further investigated to gain insight into a rare but grave disease.

Central Nervous System Infections Due to Streptococcus anginosus Group: A Single-Center Case Series

BACKGROUND

The Streptococcus anginosus group is known for its pathogenicity and tendency for abscess formation. The S anginosus group also causes brain abscesses, yet few studies describe this presentation in the pediatric neurology literature. We describe 5 patients with central nervous system infection due to S anginosus group evaluated by child neurologists at the University of Iowa from 2014 to 2020.

METHODS

We performed a retrospective case series review of electronic medical records detailing the clinical presentation and course of pediatric patients with S anginosus group-associated central nervous system infection.

RESULTS

We identified 4 males and 1 female (8, 11, 14, 16, and 21 years). Brain imaging showed abscesses in 4 cases and empyema in 1. All underwent neurosurgical intervention and antibiotic treatment. Cultures obtained during the neurosurgical procedure grew S anginosus group (4 cases with Streptococcus intermedius and 1 with Streptococcus constellatus). An 8-year-old boy with a delayed diagnosis died from brain herniation.

CONCLUSIONS

Central nervous system infections due to the S anginosus group can be life-threatening. Neuroimaging plays a key role in the early identification of abscesses. Prompt surgical intervention and timely initiation of antibiotics are critical for optimal outcomes.

The changing microbiology of neck abscesses in children: implications for antibiotic therapy

Objectives

To provide an update on the microbiology, sensitivity rates and antibiotic prescribing patterns for superficial neck lymph node abscesses at Scotland's largest paediatric tertiary centre. Findings were compared to historical data from our institution.

Methods

A retrospective case series was conducted of paediatric patients undergoing incision and drainage of a superficial neck lymph node abscess at the Royal Hospital for Children in Glasgow, from 2018 to 2021.

Results

Thirty-nine abscesses were identified. Methicillin-susceptible Staphylococcus aureus was the commonest micro-organism (28 per cent), followed by Streptococcus pyogenes (13 per cent). Eighty-two per cent of patients were administered a drug regimen containing co-amoxiclav. Only three children required a change in their antibiotics.

Conclusion

There was a significant change in causative micro-organisms, including a decrease in S aureus and an increase in the Streptococcus anginosus group. Empirical use of co-amoxiclav is recommended. In abscesses showing no clinical improvement, second-line options such as clindamycin, cefotaxime and vancomycin should be considered.

Disseminated Streptococcus anginosus invasive infection with intracranial subdural abscess formation

We report the case of a 67-year-old woman with disseminated Streptococcus anginosus invasive infection. Even under a maximal dose of susceptible antibiotics, her condition was complicated by pulmonary septic emboli and intracranial subdural abscess. Effective antibiotics and emergent surgical drainage were performed, but the sequelae of aphasia and hemiplegia remained. Underlying immunocompromised conditions of diabetes mellitus and monoclonal gammopathy of unknown significance might partially affect the clinical course of invasive S. anginosus infection. Once the infection becomes invasive, it can be refractory and difficult to treat. Clinicians should acknowledge the characteristics of invasive S. anginosus infection.

Prevalence of red and orange microbial complexes in endodontic-periodontal lesions: a systematic review and meta-analysis

OBJECTIVE

This systematic review assesses the prevalence of microbial complexes in endodontic-periodontal lesion.

MATERIALS AND METHODS

Nine databases were searched through August 2020. Experts were consulted to indicate additional studies. Studies were blindly selected by two reviewers based on pre-defined eligibility criteria. Studies that evaluated the prevalence of microbial orange and red complexes among patients with endodontic-periodontal lesion were considered eligible. Risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data.

RESULTS

From 572 articles found on all databases, 11 clinical studies were finally included. The following microorganisms were investigated: P. gingivalis, T. forsythia, T. denticola, F. nucleatum, F. periodonticum, P. micra, P. intermedia, P. nigrescens, S. constellatus, C. gracilis, C. rectus, C. showae and E. nodatum. Considering the orange complex, P. micra, E. nodatum and S. constellatus were prevalent in both root canal and periodontal pockets. P. gingivalis and T. forsythia belonging to the red complex were prevalent only in periodontal pockets. The red complex microorganisms were not found very frequently in root canal.

CONCLUSIONS

There is a similarity between the microbiome of root canal and periodontal pockets, with prevalence of the three microorganisms of the orange complex. Two microorganisms from the red complex were prevalent only in periodontal pockets.

CLINICAL RELEVANCE

The prevalence of specific microorganisms in endodontic-periodontal lesion is important to understand the microbiological profile of the patients involved and to correlate it with possible clinical and repair conditions of this pathology.

Shotgun whole genome sequencing of drug-resistance Streptococcus anginosus strain 47S1 isolated from a patient with pharyngitis in Saudi Arabia

BACKGROUND

Streptococcus anginosus is an emergence opportunistic pathogen that colonize the human upper respiratory tract (URT), S. anginosus alongside with S. intermedius and S. constellatus, members of S. anginosus group, are implicated in several human infections. However, our understanding this bacterium to the genotype level with determining the genes associated with pathogenicity and antimicrobial resistance (AMR) is scarce. S. anginosus 47S1 strain was isolated from sore throat infection, the whole genome was characterized and the virulence & AMR genes contributing in pathogenicity were investigated.

METHODOLOGY

The whole genome of 47S1 was sequenced by Illumina sequencing technology. Strain 47S1 genome was de novo assembled with different strategies and annotated via PGAP, PROKKA and RAST pipelines. Identifying the CRISPR-Cass system and prophages sequences was performed using CRISPRloci and PhiSpy tools respectively. Prediction the virulence genes were performed with the VFDB database. AMR genes were detected in silico using NCBI AMRFinderPlus pipeline and CARD database and compared with in vitro AST findings.

RESULTS

β-hemolytic strain 47S1 was identified with conventional microbiology techniques and confirmed by the sequences of 16S rRNA gene. Genome of 47S1 comprised of 1981512 bp. Type I-C CRISPR-Cas system and 4 prophages were detected among the genome of 47S1. Several virulence genes were predicted, most of these genes are found in other pathogenic streptococci, mainly lmb, pavA, htrA/degP, eno, sagA, psaA and cpsI which play a significant role in colonizing, invading host tissues and evade form immune system. In silico AMR findings showed that 47S1 gnome harbors (tetA, tetB &tet32), (aac(6')-I, aadK &aph(3')-IVa), fusC, and PmrA genes that mediated-resistance to tetracyclines, aminoglycosides, fusidic acid, and fluoroquinolone respectively which corresponds with in vitro AST obtained results. In conclusion, WGS is a key approach to predict the virulence and AMR genes, results obtained in this study may contribute for a better understanding of the opportunistic S. anginosus pathogenicity.

Disentangling the Progression of Non-alcoholic Fatty Liver Disease in the Human Gut Microbiota

Gut microbiome dysbiosis has been known to be associated with all stages of non-alcoholic fatty liver disease (NAFLD), but questions remain about microbial profiles in progression and homogeneity across NAFLD stages. We performed a meta-analysis of three publicly shotgun datasets and built predictive models to determine diagnostic capacity. Here, we found consistently microbiome shifts across NAFLD stages, of which co-occurrence patterns and core sets of new biomarkers significantly correlated with NAFLD progression were identified. Machine learning models that are able to distinguish patients with any NAFLD stage from healthy controls remained predictive when applied to patients with other NAFLD stages, suggesting the homogeneity across stages once again. Focusing on species and metabolic pathways specifically associated with progressive stages, we found that increased toxic metabolites and decreased protection of butyrate and choline contributed to advanced NAFLD. We further built models discriminating one stage from the others with an average of 0.86 of area under the curve. In conclusion, this meta-analysis firmly establishes generalizable microbiome dysbiosis and predictive taxonomic and functional signatures as a basis for future diagnostics across NAFLD stages.

Streptococcus Intermedius as the cause of sphenoid sinusitis & associated extensive skull base and neck thrombophlebitis & thrombosis

Acute bacterial sinusitis may be complicated by orbital and intracranial involvement and by thrombophlebitis. Its spread across multiple anatomic compartments is facilitated by the interconnected venous anatomy of the head and neck and the virulence of the primary pathogen. We present a rare case of Streptococcus Intermedius (S. Intermedius) acute bacterial sinusitis complicated by extensive skull base involvement including cavernous sinuses and neck vein thrombophlebitis and thrombosis.

Parenchymal Brain Abscess as an Intracranial Complication After Sinusitis

Brain abscesses caused by sinusitis are rare in the antibiotic era. The purpose of the current manuscript was to report a rare case of a brain abscess located mainly in the frontal lobe after sinusitis, which was initially thought to be meningitis or encephalitis. A 39-year-old man was transferred to our hospital from another neighbouring hospital with tonic-clonic seizures, severe headache, and purulent nasal secretions. For one week, he was taking antibiotics for sinusitis. The computed tomography indicated lesions in the right sinuses but not in the parenchymal brain and thus antibiotics along with antiepileptic drugs were given. However, due to the deterioration of symptoms, magnetic resonance imaging was executed, which revealed an abscess in the frontal lobe. Afterward, an anterior ethmoidectomy and middle maxillary antrostomy were performed in order to drain the purulent content from the right sinuses. Ten days later, the patient presented disorientation and thus an open craniotomy for successful removal of the parenchymal abscess was performed. One month later, the patient was discharged with mild irritability, which was eliminated gradually over the next two months. Conclusively, brain abscesses can be caused by local spread from an infection of the paranasal sinus. The contribution of imaging modality is very significant not only for the early diagnosis but also for the therapeutic management of such cases. Frequently antibiotic treatment is insufficient and surgery may be required.

Antimicrobial resistance of bacterial strains in patients undergoing orthodontic treatment with and without fixed appliances

OBJECTIVES

To identify microorganisms isolated from patients wearing fixed orthodontic appliances and to evaluate the resistance of isolated bacterial strains to different antimicrobials.

MATERIALS AND METHODS

Seventeen healthy patients wearing a fixed orthodontic appliance (group 1) and six nonwearers (group 2, control group) were evaluated. The biofilm that formed around the orthodontic brackets was collected, and the samples were then plated in a chromogenic medium (chromIDT, bioMérieux). Colony-forming units (CFUs) were isolated and inoculated in blood-agar medium. Automated biochemical tests (VITEK 2, bioMérieux) were carried out to identify the genus and species of the microorganisms and the resistance provided by 43 drugs (37 antibacterial and 6 antifungal).

RESULTS

The most prevalent microbial genera identified in group 1 were Streptococcus (24.0%), Staphylococcus (20.0%), Enterobacter (12.0%), Geobacillus (12.0%), and Candida (12.0%), and the most frequent species were Enterobacter cloacae complex (13.6%) and Staphylococcus hominis (13.6%). In group 2, the most prevalent genera were Streptococcus (57.1%), Staphylococcus (14.2%), Sphingomonas (14.2%), and Enterobacter (14.2%). With regard to antimicrobial resistance, 14 of 19 (74%) isolated bacterial strains were found to be resistant to at least 1 of the tested antimicrobials.

CONCLUSIONS

The findings of the present study suggest that patients undergoing orthodontic treatment with fixed appliances have a more complex biofilm with a higher level of bacterial resistance.

Human beta defensin levels and vaginal microbiome composition in post-menopausal women diagnosed with lichen sclerosus

Human beta defensins (hBDs) may play an important role in the progression of lichen sclerosus (LS), due to their ability to induce excessive stimulation of extracellular matrix synthesis and fibroblast activation. The genetic ability of the individual to produce defensins, the presence of microbes influencing defensin production, and the sensitivity of microbes to defensins together regulate the formation of an ever-changing balance between defensin levels and microbiome composition. We investigated the potential differences in postmenopausal vaginal microbiome composition and vaginal hBD levels in LS patients compared to non-LS controls. LS patients exhibited significantly lower levels of hBD1 (p = 0.0003), and significantly higher levels of hBD2 (p = 0.0359) and hBD3 (p = 0.0002), compared to the control group. The microbiome of the LS patients was dominated by possibly harmful bacteria including Lactobacillus iners, Streptococcus anginosus or Gardnerella vaginalis known to initiate direct or indirect damage by increasing defensin level production. Our observations highlight that correcting the composition of the microbiome may be applicable in supplementary LS therapy by targeting the restoration of the beneficial flora that does not increase hBD2-3 production.

Scrotal Abscess in a Japanese Patient Caused by Prevotella bivia and Streptococcus agalactiae, Successfully Treated with Cefazolin and Amoxicillin: A Case Report

Background

Infections caused by Prevotella bivia, a gram-negative anaerobic bacillus, are rare, with no reported cases in Japan. We present a novel case of scrotal abscess in a Japanese patient co-infected with Prevotella bivia and Streptococcus agalactiae.

Case Presentation

A 41-year-old uncontrolled diabetic man complained of swelling and pain in the scrotum. On examination, computed tomography revealed an abscess of 5-cm diameter in the scrotum. Then, the abscess was incised and drained. He was treated with cefazolin empirically. Prevotella bivia and Streptococcus agalactiae were identified in the pus cultures obtained from the abscess. However, the susceptibility tests for Prevotella bivia could not be submitted. Seven days following admission, the pain reduced, and the drainage slowed. The patient was discharged on day 14 when cefazolin was discontinued and oral amoxicillin (750 mg/day) was started. Amoxicillin was continued until day 42; improvement was confirmed.

Conclusion

To the best of our knowledge, this case is the first report of Prevotella bivia in Japan. We suggest that cephem antibiotics such as cefazolin may be effective against Prevotella bivia in Japan.

Postoperative Streptococcus constellatus Bacteremia in a 75-Year-Old Patient with Pyometra: A Case Report

Patient: Female, 75-year-old

Final Diagnosis: Bacteremia • pyometra

Symptoms: Fever • vaginal discharge

Medication: —

Clinical Procedure: Curettage • drainage

Specialty: Infectious Diseases • Obstetrics and Gynecology

Prospective Observational Study of Bisphosphonate-Related Osteonecrosis of the Jaw in Multiple Myeloma: Microbiota Profiling and Cytokine Expression

PURPOSE

Define incidence and risk factors of osteonecrosis of the jaw (ONJ) and explore oral microbial signatures and host immune response as reflected by cytokine changes in saliva and serum in multiple myeloma (MM) patients on bisphosphate (BP) therapy.

PATIENTS AND METHODS

A single center observational prospective study of MM patients (n = 110) on >2 years of BP, none had ONJ at enrollment. Patients were followed every 3 months for 18 months with clinical/dental examination and serial measurements of inflammatory cytokines, bone turnover markers, and angiogenic growth factors. Oral microbiota was characterized by sequencing of 16S rRNA gene from saliva.

RESULTS

Over the study period 14 patients (13%) developed BRONJ, at a median of 5.7 years (95% CI: 1.9-12.0) from MM diagnosis. Chronic periodontal disease was the main clinically observed risk factor. Oral microbial profiling revealed lower bacterial richness/diversity in BRONJ. Streptococcus intermedius, S. mutans, and S. perioris were abundant in controls; S. sonstellatus and S anginosus were prevalent in BRONJ. In the saliva, at baseline patients who developed BRONJ had higher levels of MIP-1β; TNF-α and IL-6 compared to those without BRONJ, cytokine profile consistent with M-1 macrophage activation. In the serum, patients with BRONJ have significantly lower levels of TGF beta and VEGF over the study period.

CONCLUSION

Periodontal disease associated with low microbial diversity and predominance of invasive species with a proinflammatory cytokine profile leading to tissue damage and alteration of immunity seems to be the main culprit in pathogenesis of BRONJ.

Pathologic fracture and hardware failure in Streptococcus anginosus femoral osteomyelitis: Case report

Introduction

Pathologic fracture of the femur due to Streptococcus anginosus osteomyelitis has rarely been described. With limited evidence for treating S. anginosus osteomyelitis, the orthopaedic surgeon is presented with a difficult treatment decision at index presentation. Presented here is a case of failed conservative management, diagnostic dilemma, failed hardware stabilization, and definitive surgical treatment resulting in good clinical outcome.

Case presentation

A 69-year-old male experienced acute right thigh pain, edema, and erythema after dental treatment 17 days prior. He was diagnosed with right femoral diaphyseal osteomyelitis and Brodie's abscess. Blood cultures grew S. anginosus, but all site-specific tissue cultures resulted negative. Initial management consisted of intravenous antibiotic therapy and percutaneous abscess drainage. Months later, the patient sustained a displaced pathologic fracture of the diaphyseal femur and there was concern for neoplasm, but biopsies were negative. Stabilization was attempted with a lateral plate and screws. This hardware catastrophically failed in the setting of an oligotrophic femoral nonunion. Ultimately, the patient was successfully treated with an intramedullary nail coated with antibiotic-impregnated cement. Twelve months later, the patient achieved clinical and radiographic healing with no evidence of relapse of his osteomyelitis.

Clinical discussion

Conservative management of S. anginosus femoral osteomyelitis was inadequate and corroborates the existing literature. S. anginosus osteomyelitis and pyomyositis may be most optimally treated aggressively with early surgical intervention.

Conclusion

Early surgical debridement and stabilization of the compromised bone with an antibiotic coated intramedullary nail following medullary reaming may prevent pathologic fracture, eradicate infection, and achieve predictable outcomes.

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S. anginosus femoral osteomyelitis is rare and difficult to diagnose and treat.

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Conservative measures failed, and pathologic fracture later ensued.

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Although sparse, existing reports suggest early surgical management is indicated.

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This report provides more evidence for early and aggressive surgical management.

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Good outcome was achieved with antibiotic coated intramedullary nailing.

Role of Streptococcus intermedius phosphoglucosamine mutase in bacterial growth, cell morphology, and resistance to polymorphonuclear leukocyte killing

OBJECTIVES

Streptococcus intermedius is a member of the anginosus group of streptococci, an oral commensal bacterium found in infected root canals, and the causative agent of deep-seated abscesses. This organism has slow clearance when phagocytosed within neutrophils. Here, we investigated the role of its phosphoglucosamine mutase (GlmM), an enzyme associated with peptidoglycan synthesis, in bacterial growth, cell morphology, and resistance to polymorphonuclear leukocyte killing.

METHODS

The glmM-deletion (ΔglmM) mutant and the plasmid-borne complementation (ΔglmM/glmM) strain of S. intermedius were generated. The wild type, the ΔglmM mutant, and the ΔglmM/glmM strain were phagocytosed with human polymorphonuclear leukocytes (PMNs), and bacterial viability in PMNs was determined by LIVE/DEAD staining. Additionally, bacterial growth and cell morphology were also compared.

RESULTS

The survival rate of the ΔglmM mutant was significant lower than that of the wild type. Although the difference in the survival rate of the ΔglmM/glmM strain compared to that of the wild type or the ΔglmM mutant was not significant, the rate appeared to be restored to the middle level. Compared to the wild type and the ΔglmM/glmM strain, the ΔglmM mutant showed reduced growth potential, a significant increase in the number of bacterial chains, and heterogeneous bacteria.

CONCLUSIONS

GlmM is one of the factors responsible for the stable resistance of S. intermedius to clearance by PMNs.

Cardiorespiratory performance capacity and airway microbiome in patients following primary repair of esophageal atresia

BACKGROUND

Patients following repair of an esophageal atresia (EA) or tracheoesophageal fistula (TEF) carry an increased risk of long-term cardiopulmonary malaise. The role of the airway microbiome in EA/TEF patients remains unclear.

METHODS

All EA/TEF patients treated between 1980 and 2010 were invited to a prospective clinical examination, spirometry, and spiroergometry. The airway microbiome was determined from deep induced sputum by 16 S rRNA gene sequencing. The results were compared to a healthy age- and sex-matched control group.

RESULTS

Nineteen EA/TEF patients with a mean age of 24.7 ± 7 years and 19 age- and sex-matched controls were included. EA/TEF patients showed a significantly lower muscle mass, lower maximum vital capacity (VC_max), and higher rates of restrictive ventilation disorders. Spiroergometry revealed a significantly lower relative performance capacity and lower peak VO₂ in EA/TEF patients. Alpha- and beta-diversity of the airway microbiome did not differ significantly between the two groups. Linear discriminant effect size analysis revealed significantly enriched species of Prevotella_uncultured, Streptococcus_anginosus, Prevotella_7_Prevotella_enoeca, and Mogibacterium_timidum.

CONCLUSION

EA/TEF patients frequently suffer from restrictive ventilation disorders and impaired cardiopulmonary function associated with minor alterations of the airway microbiome. Long-term examinations of EA/TEF patients seem to be necessary in order to detect impaired cardiopulmonary function.

IMPACT

The key messages of the present study are a significantly decreased VC_max and exercise performance, as well as airway microbiome differences in EA/TEF patients. This study is the first to present parameters of lung function and exercise performance in combination with airway microbiome analysis with a mean follow-up of 24 years in EA/TEF patients. Prospective, long-term studies are needed to unravel possible interactions between alterations of the airway microbiome and impaired pulmonary function in EA/TEF patients.

Oral infectious bacteria in dental plaque and saliva as risk factors in patients with esophageal cancer

BACKGROUND

High levels of periodontopathic bacteria as well as Streptococcus anginosus were detected in cancer tissue from patients with esophageal cancer. An association between oral infectious bacteria and esophageal cancer has been reported.

METHODS

Characteristics of the oral microbiota and periodontal conditions were studied as clinicopathologic factors in patients with esophageal cancer. The study included 61 patients with esophageal cancer and 62 matched individuals without any cancers. Samples of subgingival dental plaque and unstimulated saliva were collected to evaluate the prevalence and abundance of the following oral bacteria using a real-time polymerase chain reaction assay: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Treponema denticola, and S. anginosus.

RESULTS

In the cancer group, the prevalence of all bacteria, with the exception of F. nucleatum, in dental plaque; the prevalence of A. actinomycetemcomitans in saliva; the abundance of all bacteria, with the exception of F. nucleatum and P. intermedia, in dental plaque; and the abundance of A. actinomycetemcomitans and S. anginosus in saliva were significantly higher. Furthermore, a logistic regression analysis suggested that the prevalence of T. forsythia and S. anginosus in dental plaque and of A. actinomycetemcomitans in saliva, as well as a drinking habit, were associated with a high risk of esophageal cancer, with a high odds ratio.

CONCLUSIONS

The current findings have potential implications for the early diagnosis of esophageal cancer.

Asymptomatic man with an incidental finding of a massive empyema

We describe the case of a 67-year-old asymptomatic man who was referred to our hospital for abnormal laboratory results. He was incidentally found to have a massive empyema without underlying bronchopulmonary pneumonia. Following thoracentesis, he was diagnosed with chronic Streptococcus anginosus empyema. Therapeutic thoracentesis and treatment with tissue plasminogen activator and deoxyribonuclease failed to resolve the empyema, and there was residual loculated pleural fluid that was surrounded by a thick rind. The patient was referred to thoracic surgery for decortication of the pleural space via video-assisted thoracoscopic surgery. At 2-month follow-up, the patient had complete re-expansion of the lung tissue.

In Vivo Dynamic Monitoring of Bacterial Infection by NIR-II Fluorescence Imaging

Time window of antibiotic administration is a critical but long-neglected point in the treatment of bacterial infection, as unnecessary prolonged antibiotics are increasingly causing catastrophic drug-resistance. Here, a second near-infrared (NIR-II) fluorescence imaging strategy based on lead sulfide quantum dots (PbS QDs) is presented to dynamically monitor bacterial infection in vivo in a real-time manner. The prepared PbS QDs not only provide a low detection limit (10⁴ CFU mL^-1 ) of four typical bacteria strains in vitro but also show a particularly high labeling efficiency with Escherichia coli (E. coli). The NIR-II in vivo imaging results reveal that the number of invading bacteria first decreases after post-injection, then increases from 1 d to 1 week and drop again over time in infected mouse models. Meanwhile, there is a simultaneous variation of dendritic cells, neutrophils, macrophages, and CD8+ T lymphocytes against bacterial infection at the same time points. Notably, the infected mouse self-heals eventually without antibiotic treatment, as a robust immune system can successfully prevent further health deterioration. The NIR-II imaging approach enables real-time monitoring of bacterial infection in vivo, thus facilitating spatiotemporal deciphering of time window for antibiotic treatment.

Acute Presentation of Simultaneous Liver Abscesses Caused by Streptococcus constellatus

Simultaneous liver abscesses are rarely seen and reported. We are reporting a case of two simultaneous, complex liver abscesses in a patient who had no evidence of liver abscess on cross-sectional imaging close to three months prior to this presentation. These abscesses were 7-8 cm in size, large, and septated. Microbiological studies were positive for Streptococcus constellatus, which is a known cause of pyogenic liver abscess. In our patient, pyogenic liver abscesses were associated with bacteremia and sepsis. This patient was managed with broad spectrum parenteral antibiotics and percutaneous drainage with improvement in clinical condition. This patient was discharged home with a peripherally inserted central catheter (PICC) line in place to complete a six-week course of parenteral antibiotics. A complete history and physical with pertinent examination findings are key to diagnosis of liver abscess. S. constellatus should be considered in the differential diagnosis of patients with liver abscess and sepsis.

Clinical Characteristics of Infections Caused by Streptococcus Anginosus Group

This study aimed to investigate the clinical characteristics, distribution of different strains and risk factors of patients infected with Streptococcus anginosus group (SAG). In the population of 463 patients, the male-to-female ratio was 1.95:1, and the patient age ranged from 6 months to 103 years. There were 49 children (10.58%), 311 young and middle-aged adults (67.17%), and 103 elderly adults (22.25%). Approximately 45.4% had underlying conditions, which were mostly malignant tumors and diabetes. Of the 463 specimens, 254 were S. anginosus (54.86%), 173 were S. constellatus (37.37%), and 36 were S. intermedius (7.77%). According to the age distribution, the incidence peaked in the 35–54 year age group. Different sites of infection had statistically significant differences regarding the constituent ratios of these three species. Different age groups also exhibited statistically significant differences in constituent ratios of the pathogenic organisms, as well as organ infections. In our population, 269 were clinically cured, 184 reported satisfactory improvement, and 10 died. SAG, as an opportunistic pathogen, can induce pyogenic infections in patients of all ages and shows no significant gender predilection in any age group. The three pathogenic organisms had differences with respect to patient age and infections of body sites.

Draft Genome Sequence of Streptococcus anginosus UMB7768, Isolated from a Woman with Recurrent UTI Symptoms

Streptococcus anginosus recently was implicated as a pathogen involved in urinary tract infections. A strain of S. anginosus was isolated from the female urogenital tract. Here, we present the draft genome sequence of S. anginosus strain UMB7768.

Streptococcus anginosus recently was implicated as a pathogen involved in urinary tract infections. A strain of S. anginosus was isolated from the female urogenital tract. Here, we present the draft genome sequence of S. anginosus strain UMB7768.

Draft Genome Sequence of Streptococcus anginosus UMB1296, Isolated from the Female Urinary Tract

We present the draft genome sequence of a Streptococcus anginosus strain isolated from the female urinary tract. The S. anginosus UMB1296 draft genome has a size of 1,924,009 bp assembled into 35 contigs with a GC content of 38.69%. Genome annotation revealed 1,775 protein-coding genes, including several known virulence factors.

We present the draft genome sequence of a Streptococcus anginosus strain isolated from the female urinary tract. The S. anginosus UMB1296 draft genome has a size of 1,924,009 bp assembled into 35 contigs with a GC content of 38.69%. Genome annotation revealed 1,775 protein-coding genes, including several known virulence factors.

Does bacterial colonization during embryo transfer have an impact on pregnancy rate in ICSI? : Tunisian preliminary results

INTRODUCTION

Embryos' transfer into the uterine cavity remains a limiting factor in the success of intracytoplasmic sperm injection (ICSI). This study aimed to evaluate the impact of cervico-vaginal colonization on ICSI outcomes.

MATERIEL AND METHODS

Longitudinal, prospective and analytical study, conducted from February 1 st to October 31 st, 2017. On the day of embryos' transfer, patients with the following criteria were included: Age ≤ 40, normal uterine ultrasound and hysteroscopy, first or second attempt of ICSI, use of fresh semen and transfer of at least one good quality embryo. Three samples were done for microbiological analysis: vaginal secretions, cervical mucus and the tip of the transfer catheter.

RESULTS

The study included 40 patients. Pregnancy rate was 52.5 %. Catheter contamination occurred in nine cases (22.5 %). The most frequently isolated bacteria were Streptococcus anginosus (37 % of cases), Gardnerella vaginalis (27 % of cases) and Streptococcus agalactiae (18 % of cases). In all cases of contamination, the same bacteria were found also in the vagina and cervical mucus. In cases of contamination with Gardnerella vaginalis, the study of vaginal flora showed bacterial vaginosis. No pregnancy was obtained when contamination of the transfer catheter occurred. In the absence of contamination, pregnancy rate was 61.2 % (ρ = 0.003). Both populations (patients with catheter contamination and patients without catheter contamination) were comparable regarding epidemiological characteristics and ICSI attempt data.

CONCLUSION

Contamination of the transfer catheter by cervical-vaginal bacteria appears to affect IVF results. Systematic antibiotic prophylaxis could be proposed to reduce this negative impact.

COMPLICATED PNEUMONIA WITH EMPYEMA CAUSED BY STREPTOCOCCUS ANGINOSUS IN A CHILD

Objective:

To highlight the pathogenicity of Streptococcus anginosus, which is rare in pediatric patients, but can cause severe infections that are known to have a better outcome when treated early with interventional procedures and prolonged antibiotic therapy.

Case

description: The patient is a 6-year-old boy with global developmental delay, examined in the emergency room due to fever and respiratory distress. The physical examination and diagnostic workout revealed complicated pneumonia with empyema of the left hemithorax; he started antibiotic therapy and underwent thoracic drainage. Pleural fluid cultures grew Streptococcus anginosus. On day 11, the child had a clinical deterioration with recurrence of fever, hypoxia, and respiratory distress. At this point, considering the causative agent, he was submitted to video-assisted thoracoscopic decortication, with good progress thereafter.

Comments:

Streptococcus anginosus is a commensal bacterium of the human oral cavity capable of causing severe systemic infections. Although reports of complicated thoracic infections with this agent are rare in the pediatric population, they have been increasing in adults. Streptococcus anginosus has a high capacity to form abscess and empyema, requiring different therapeutic approaches when compared to complicated pneumonia caused by other agents.

Heterogeneity of Streptococcus anginosus ß-hemolysis in relation to CRISPR/Cas

Streptococcus anginosus is a commensal of the oral mucosa that can cause severe invasive infections. A considerable proportion of Streptococcus anginosus strains are ß-hemolytic due to the presence of an SLS-like gene cluster. However, the majority of strains do not display ß-hemolysis. To investigate ß-hemolysin heterogeneity in S. anginosus, we determined the presence of sag genes and correlated it with the presence of CRISPR/Cas genes in a collection of ß-hemolytic and non-ß-hemolytic strains. All of the ß-hemolytic strains carried the sag gene cluster. In contrast to other streptococci, clinical S. anginosus strains that do not display ß-hemolysis do not harbor sag genes. Phylogenetic analysis of the ß-hemolytic strains revealed that they belong to two previously defined clusters within S. anginosus. Correlation with CRISPR/Cas genes showed a significant difference for the presence of CRISPR/Cas in ß-hemolytic versus non-ß-hemolytic isolates. The presence of the CRISPR/Cas type IIA or type IIC locus is associated with the absence of sag genes; in 65% of the non-ß-hemolytic strains a CRISPR/Cas locus was found, while only 24% of ß-hemolytic strains carry CRISPR/Cas genes. Further analysis of the spacer content of the CRISPR systems revealed the presence of multiple self-targeting sequences directed against S. anginosus genes. These results support the hypothesis that horizontal gene transfer is involved in the acquisition of ß-hemolysin genes and that CRISPR/Cas may limit DNA uptake in S. anginosus.

Incidence and Clinical Outcomes of Streptococcus anginosus in Acute Complicated Sinusitis: A Pediatric Cohort

We conducted a retrospective cohort study of 160 hospitalized children admitted for acute complicated sinusitis and compared children with S anginosus-associated infection to children with other or no pathogens identified. The incidence of S anginosus-associated infections increased 12% per year, and infections with S anginosus are associated with increased morbidity.

First report of subcutaneous abscess caused by Porphyromonas gingivalis

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P. gingivalis is a gram-negative bacterium, frequently found in dental plaque.

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Porphyromonas infection of the skin is considered rare.

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Skin abscesses have known involvement with Streptococcus and Staphylococcus species.

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Porphyromonas is more commonly associated with oral infections.

Approximately 90% of skin infections are thought to be attributable to Staphylococcus aureus and Streptococcus pyogenes, along with some anaerobic bacteria such as Bacteroides and Prevotella species, which are considered significant causative agents in post-operative skin infections especially in diabetics. Species from the anaerobic Porphyromonas genus are known to cause oral infections, but rarely cause infection of the skin. In this case report, we describe a subcutaneous abscess caused by Porphyromonas gingivalis in a 67-year-old man who had started chemotherapy for lung cancer (cT3N3M0 stage Ⅲ B) three days prior to consulting a dermatologist. On clinical examination, a fist-sized mass with a hot sensation was observed in the left temporal region of the face, and treatment with cefazolin was commenced at 6 g/day. After three days, the mass was drained via skin incision and pus culture was performed, which revealed infection with P. gingivalis. The patient was successfully treated with abscess drainage and antibiotics therapy. We suggest that in tandem with immunosuppression, P. gingivalis could be a cause of skin infections.