Veillonella parvula discitis and secondary bacteremia: a rare infection complicating endoscopy and colonoscopy?

Veillonella Discitis: A Rare Presentation and Review of Literature

Background

Veillonella is an anaerobic gram-negative coccus found as a commensal organism in the oral, respiratory, gastrointestinal, and genitourinary tract of humans. Rarely, it can cause serious infections by the production of lipopolysaccharide, an endotoxin. Although most Veillonella infections occur in immunocompromised individuals, we herein describe cases of Veillonella discitis, a rare presentation of Veillonella, in immunocompetent patients.

Case Presentation

The first presented case was encountered in a patient admitted at our facility. All patient data were obtained from the hospital's electronic medical record system. Thereafter, a literature search and subsequent review was done on PubMed with the MEDLINE database, using the term "Veillonella discitis," to obtain other reported cases of discitis caused by Veillonella.We found a total of 9 cases of Veillonella discitis in immunocompetent patients, apart from our patient. It was most frequently found in those aged 60 to 70 years, with no particular association with patient sex. Chronic backache was the most reported presenting symptom, the lumbar spine being the most commonly affected area, with a high number of cases occurring in the presence of an inciting event. Ceftriaxone, amoxicillin, and clavulanic acid were the most commonly used drugs, with an average duration of therapy of 6 weeks.

Conclusion

The objective of our study was to highlight the importance of recognizing Veillonella as a potential cause of discitis. We aim to educate medical professionals regarding the presentation of Veillonella discitis, the demographic groups affected, predisposing factors, and the treatment options available.

Roles of oral and gut microbiota in acute myocardial infarction

INTRODUCTION

The significance of oral/gut microbiota in acute myocardial infarction (AMI) has been increasingly appreciated. However, correlations between oral/gut microbiota and AMI parameter, as well as the key microbiota that may have a crucial function in this process, remain unclear.

OBJECTIVES

To investigate the composition and structure of oral and gut microbiota associated with AMI and explore the roles of specific bacterial species in the progression of AMI.

METHODS

We conducted a case-control study with 37 AMI patients and 36 controls. Oral and gut sample were collected and sequenced. Using correlation analysis, we combined bioinformatics data with AMI clinical parameters and obtained heatmaps of correlation coefficients. Additionally, we used antibiotics to eliminate the gut microbiota of C57BL/6J mice, followed by the transplantation of selected bacteria to verify the gut colonization of oral bacteria and their impact on AMI.

RESULTS

The component of oral and gut microbiota of AMI group showed significant alterations when compared to the control group. 17 salivary genera, 21 subgingival genera, and 8 gut genera in AMI group substantially differed from those in control group. Additionally, 19 genera from saliva, 19 genera from subgingival plaque, and 11 genera from feces substantially correlated with AMI clinical parameters. Orally administrated S.o (Streptococcus oralis subsp. dentisani), S.p (Streptococcus parasanguinis), and S.s (Streptococcus salivarius) were able to colonize in the gut and exacerbate myocardial infarction.

CONCLUSION

There is a strong correlation between oral/gut microbiota and AMI. Streptococcus spp. is capable to transmit from oral to gut and exacerbate myocardial infarction in mice. Monitoring and control of specific oral microbiota may be an effective new strategy for improving the therapy of AMI.

Bacteremia caused by Veillonella parvula: Two case reports and a review of the literature

Veillonella parvula is a non-motile gram-negative coccus that forms part of the normal microbiota in several body sites and which has been rarely isolated as cause of infections in human population, particularly in bacteremias. Here we give the overview of characteristics of genus Veillonella and the summary of its role in infections, particularly in bacteremia. We additionally report two patients with bacteremia due to V. parvula. Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as V. parvula by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. The two patients were male and one of them had risk factors for anaerobic bacteremia. The isolates were susceptible to most antibiotics and the outcome was successful in both patients. Bacteremia due to V. parvula is still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification of these species.

Role of Oral Veillonella Species in Predicting Surgical Site Infections After Maxillofacial Trauma: A Prospective Observational Study

INTRODUCTION

There are comparatively fewer surgical site infections after craniofacial trauma than after trauma to the extremities, and the etiology is complex. Gram-negative facultative anaerobic bacteria Veillonella is a common commensal in the oral cavity and has been linked to osteomyelitis and surgical site infections in prosthetic joint infections. They serve as early biological indicators.

AIMS/OBJECTIVES

This study aims to assess the presence of Veillonella in patients presenting with maxillofacial trauma, to document the difference in colony count in patients requiring surgical intervention at different time intervals as against patients with surgical site infections, and to provide better hospital care and management so as to improve the standard of care with an attempt to prevent the possibility of postoperative surgical site infections.

METHODOLOGY

In this study, individuals with trauma/fractures of the maxillofacial region requiring surgical intervention at varied time spans, early, intermediate, and late, were included. After obtaining informed consent, the examination was done; the fracture type and site were noted, and a swab was taken on the day of admission, on the day of surgery, and on the day of discharge and given for microbiological evaluation. Findings were recorded.

RESULTS

The primary and secondary objectives of the study were established. The mean colony count in colony-forming units/milliliter for patients undergoing early surgical intervention, on the day of admission, was 2.01E+0.6. On the day of discharge, the mean colony count was 1.51E+0.6. In contrast, for patients with surgical site infection, on the day of admission, the mean was 6.5E+0.7, and on the day of discharge, the mean colony count reduced to 4.01E+0.6. The time-colony-forming unit graph showed a difference in the colony count of Veillonella in patients operated at different time intervals as against patients with surgical site infection and modified relation with a number of other oral commensals. The colony count in patients with osteomyelitis was found and compared.

CONCLUSION

There is a change in the colony count of Veillonella species and its relation to their commensals when intervened at different time intervals. Our study indicates that the estimation of Veillonella species and the colony count could aid in determining the possibility of a surgical site infection. This study also stresses on the appropriate reporting of maxillofacial trauma in cases of a poly-trauma for appropriate management.

Bacteroidaceae, Bacteroides, and Veillonella: emerging protectors against Graves' disease

Background

Graves' disease (GD) is the most common cause of hyperthyroidism, and its pathogenesis remains incompletely elucidated. Numerous studies have implicated the gut microbiota in the development of thyroid disorders. This study employs Mendelian randomization analysis to investigate the characteristics of gut microbiota in GD patients, aiming to offer novel insights into the etiology and treatment of Graves' disease.

Methods

Two-sample Mendelian randomization (MR) analysis was employed to assess the causal relationship between Graves' disease and the gut microbiota composition. Gut microbiota data were sourced from the international consortium MiBioGen, while Graves' disease data were obtained from FINNGEN. Eligible single nucleotide polymorphisms (SNPs) were selected as instrumental variables. Multiple analysis methods, including inverse variance-weighted (IVW), MR-Egger regression, weighted median, weighted mode, and MR-RAPS, were utilized. Sensitivity analyses were conducted employing MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis as quality control measures.

Results

The Mendelian randomization study conducted in a European population revealed a decreased risk of Graves' disease associated with Bacteroidaceae (Odds ratio (OR) [95% confidence interval (CI)]: 0.89 [0.89 ~ 0.90], adjusted P value: <0.001), Bacteroides (OR: [95% CI]: 0.555 [0.437 ~ 0.706], adjusted P value: <0.001), and Veillonella (OR [95% CI]: 0.632 [0.492 ~ 0.811], adjusted P value: 0.016). No significant evidence of heterogeneity, or horizontal pleiotropy was detected. Furthermore, the preliminary MR analysis identified 13 bacterial species including Eubacterium brachy group and Family XIII AD3011 group, exhibiting significant associations with Graves' disease onset, suggesting potential causal effects.

Conclusion

A causal relationship exists between gut microbiota and Graves' disease. Bacteroidaceae, Bacteroides, and Veillonella emerge as protective factors against Graves' disease development. Prospective probiotic supplementation may offer a novel avenue for adjunctive treatment in the management of Graves' disease in the future.

Bergapten exerts a chondroprotective effect in temporomandibular joint osteoarthritis by combining intestinal flora alteration and reactive oxygen species reduction

Bergapten, a furanocoumarin naturally occurring in bergamot essential oil, has been demonstrated to have the potential to alleviate osteoarthritis-related symptoms via its anti-inflammatory activity. Although its systemic bioavailability is limited, its precise mechanisms of action and effects on temporomandibular joint osteoarthritis (TMJOA) and its relationship with the intestinal flora remain unclear. Here, we explored the anti-TMJOA effect of BGT combined with the interleukin-1β-induced inflammatory response of chondrocytes in a monosodium iodoacetate (MIA)-induced TMJOA rat model. It was confirmed that BGT effectively reduced proinflammatory mediators and increased type II collagen, bone volume, and trabecular number of condyles in TMJOA rats. Importantly, the oral administration of BGT altered the intestinal flora of rats by increasing the relative abundances of nine prebiotic species and decreasing the relative abundance of one potential species. In addition, BGT considerably reduced reactive oxygen species (ROS) levels by suppressing glutathione, oxidized glutathione, and superoxide dismutase in the serum and malondialdehyde in urine. These results suggest that BGT exerts a chondroprotective effect, most likely by improving the intestinal flora and reducing ROS production associated with TMJOA in rats. This finding indicates a novel beneficial effect of BGT on the prevention and treatment of TMJOA.

Correlation between gut microbiota and the development of Graves' disease: A prospective study

The association between gut microbiota and development of Graves' disease (GD) remains unclear. This study aimed to profile the gut microbiota of 65 patients newly diagnosed with GD before and after treatment and 33 physical examination personnel via 16S rRNA sequencing. Significant differences in the gut microbiota composition were observed between the two groups, showing relative bacterial abundances of 1 class, 1 order, 5 families, and 14 genera. After treatment, the abundance of the significantly enriched biota in the GD group decreased considerably, whereas that of the previously decreased biota increased considerably. Further, interleukin-17 levels decreased significantly. The random forest method was used to identify 12 genera that can distinguish patients with GD from healthy controls. Our study revealed that the gut microbiota of patients with GD exhibit unique characteristics compared with that of healthy individuals, which may be related to an imbalance in the immune system and gut microbiota.

Veillonella Bacteremia in a Patient With Metastatic Colorectal Carcinoma

Colorectal carcinoma has increasingly been reported to be associated with gut microbial dysbiosis. Bacteroides, Fusobacterium, Faecalibacterium, Blautia, etc., are gut microbes commonly associated with colorectal carcinoma. Gut microbial dysregulation secondary to infectious, inflammatory, toxin exposure or change in dietary habits coupled with the disruption of the inner mucosal layer overlying the luminal epithelium is hypothesized as the inciting events leading to microbial invasion and subsequent tumorigenesis. Although the precise mechanism is unclear, disruption of normal host responses like inflammation, apoptosis, cellular proliferation, free radical injury, production of oncogenic toxins, etc., is postulated to play a role. We report a case of Veillonella bacteremia in a patient with metastatic colorectal carcinoma without a preceding history of periodontal disease. The patient was managed with ampicillin-sulbactam, which was followed by subsequent negative blood cultures. This case report signifies the association of gut microbiota like Veillonella with colorectal carcinoma and the importance of subsequent screening for colorectal cancer following Veillonella bacteremia.

A novel approach for combining the metagenome, metaresistome, metareplicome and causal inference to determine the microbes and their antibiotic resistance gene repertoire that contribute to dysbiosis

The use of whole metagenomic data to infer the relative abundance of all its microbes is well established. The same data can be used to determine the replication rate of all eubacterial taxa with circular chromosomes. Despite their availability, the replication rate profiles (metareplicome) have not been fully exploited in microbiome analyses. Another relatively new approach is the application of causal inferencing to analyse microbiome data that goes beyond correlational studies. A novel scalable pipeline called MeRRCI (Metagenome, metaResistome, and metaReplicome for Causal Inferencing) was developed. MeRRCI combines efficient computation of the metagenome (bacterial relative abundance), metaresistome (antimicrobial gene abundance) and metareplicome (replication rates), and integrates environmental variables (metadata) for causality analysis using Bayesian networks. MeRRCI was applied to an infant gut microbiome data set to investigate the microbial community's response to antibiotics. Our analysis suggests that the current treatment stratagem contributes to preterm infant gut dysbiosis, allowing a proliferation of pathobionts. The study highlights the specific antibacterial resistance genes that may contribute to exponential cell division in the presence of antibiotics for various pathogens, namely Klebsiella pneumoniae, Citrobacter freundii, Staphylococcus epidermidis, Veilonella parvula and Clostridium perfringens. These organisms often contribute to the harmful long-term sequelae seen in these young infants.

Stage-specific roles of microbial dysbiosis and metabolic disorders in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a progressive disease including four stages, where gut microbiome is associated with pathogenesis. We aimed to investigate stage-specific roles of microbial dysbiosis and metabolic disorders in RA.

METHODS

We investigated stage-based profiles of faecal metagenome and plasma metabolome of 76 individuals with RA grouped into four stages (stages I-IV) according to 2010 RA classification criteria, 19 individuals with osteroarthritis and 27 healthy individuals. To verify bacterial invasion of joint synovial fluid, 16S rRNA gene sequencing, bacterial isolation and scanning electron microscopy were conducted on another validation cohort of 271 patients from four RA stages.

RESULTS

First, depletion of Bacteroides uniformis and Bacteroides plebeius weakened glycosaminoglycan metabolism (p<0.001), continuously hurting articular cartilage across four stages. Second, elevation of Escherichia coli enhanced arginine succinyltransferase pathway in the stage II and stage III (p<0.001), which was correlated with the increase of the rheumatoid factor (p=1.35×10-3) and could induce bone loss. Third, abnormally high levels of methoxyacetic acid (p=1.28×10-8) and cysteine-S-sulfate (p=4.66×10-12) inhibited osteoblasts in the stage II and enhanced osteoclasts in the stage III, respectively, promoting bone erosion. Fourth, continuous increase of gut permeability may induce gut microbial invasion of the joint synovial fluid in the stage IV.

CONCLUSIONS

Clinical microbial intervention should consider the RA stage, where microbial dysbiosis and metabolic disorders present distinct patterns and played stage-specific roles. Our work provides a new insight in understanding gut-joint axis from a perspective of stages, which opens up new avenues for RA prognosis and therapy.

Gut bacterial profiles in Parkinson's disease: A systematic review

INTRODUCTION

Recent advances have highlighted the relationships between gut dysbiosis and Parkinson's disease (PD). Microbiota transplantation from PD patients to mice can induce increased alpha-synuclein-mediated motor deficits. Human studies have identified differences in the gut microbiota of PD patients compared to healthy controls. We undertook a systematic review to evaluate the available evidence for the involvement of gut bacteria in the etiology of PD.

METHODS

The PubMed databank, the China National Knowledge Infrastructure databank, and Wanfang Data were searched from inception until June 2021 to identify human case-control studies that investigated relationships between PD and microbiota quantified from feces. We evaluated the resulting studies focusing on bacterial taxa that were different between PD patients and healthy controls.

RESULTS

Twenty-six studies were found in which 53 microbial families and 98 genera exhibited differences between patients with PD and healthy controls. The genera identified by more than two studies as increased in PD were Bifidobacterium, Alistipes, Christensenella, Enterococcus, Oscillospira, Bilophila, Desulfovibrio, Escherichia/Shigella, and Akkermansia, while Prevotella, Blautia, Faecalibacterium, Fusicatenibacter, and Haemophilus had three or more reports of being lower in PD patients. More than one report demonstrated that Bacteroides, Odoribacter, Parabacteroides, Butyricicoccus, Butyrivibrio, Clostridium, Coprococcus, Lachnospira, Lactobacillus, Megasphaera, Phascolarctobacterium, Roseburia, Ruminococcus, Streptococcus, and Klebsiella were altered in both directions.

CONCLUSION

Our review shows that the involvement of the gut microbiome in the etiology of PD may involve alterations of short-chain fatty acids (SCFAs)-producing bacteria and an increase in putative gut pathobionts. SCFAs-producing bacteria may vary above or below an "optimal range," causing imbalances. Considering that Bifidobacterium, Lactobacillus, and Akkermansia are beneficial for human health, increased Bifidobacterium and Lactobacillus in the PD gut microbiome may be associated with PD medications, especially COMT inhibitors, while a high level of Akkermansia may be associated with aging.

Severe disseminated Veillonella parvula infection including endocarditis, bilateral psoas abscess, discitis, and osteomyelitis but sparing spinal and hip prostheses: a case report

Background

Veillonella species are an opportunistically pathogenic commensal anaerobic Gram-negative coccus commonly found in the oral, genitourinary, respiratory, and intestinal tract of humans and some animals. Infection is rare, even in immunocompromised hosts, and has been identified to cause a wide array of different infections, including endocarditis, osteomyelitis, and meningitis.

Case presentation

An 82-year-old Caucasian male retired ex-gymnast presented to the emergency department with a 2-week history of acute on chronic lower back pain without clear precipitant. He displayed no systemic symptoms, and had not sustained any recent injuries. Initial blood and radiological investigation did not reveal an infective or mechanical cause for his pain; however, a few days into admission, he developed a fever and signs of sepsis. A thorough septic screen was performed, including a spinal magnetic resonance imaging scan, which did not reveal any abnormalities. Blood cultures revealed Veillonella parvula bacteremia, with subsequently repeated magnetic resonance imaging displaying rapid disseminated infection including bilateral psoas abscess, discitis, and osteomyelitis. Infective endocarditis was later identified with echocardiogram. He received intravenous ceftriaxone and later oral amoxicillin and clavulanic and recovered on 6-month follow-up.

Conclusions

This case illustrates the potential pathogenicity and unexpected rapid course of Veillonella parvula infection even in an immunocompetent host presenting with back pain. This case highlights the critical importance of a thorough septic screen when investigating patients for early signs of sepsis.

Relevance of Intestinal Microbiota in Immunoglobulin A Vasculitis With Abdominal Involvement

BACKGROUND

We explored the intestinal microbiota changes in IgAV with abdominal involvement (IgAV-GI) at the acute and convalescent stages and evaluated the role of intestinal microbiota in the clinical course of patients with IgAV.

METHODS

A total of 37 patients with IgAV were included, and the control group comprised 37 age- and sex-matched healthy children. Stool samples were collected from 28 children with IgAV-GI (19 in the acute stage and 9 in the recovery stage) and from nine children with non-abdominal involvement. Fecal specimens were selected and DNA was obtained using an extraction kit which was then subjected to high-throughput sequencing and analysis.

RESULTS

There was no significant difference in the community structure of the intestinal microbiota among the IgAV-GI acute, IgAV-GI convalescence, and IgAV-non-GI stages. The abundance of Veillonella in the acute stage of IgAV-GI was significantly higher than that in IgAV-non-GI and convalescence stages, and Ruminococcus was the most abundant in IgAV-GI convalescence. The α-diversity of children with IgAV was significantly lower than that of healthy children, and healthy children had higher intestinal microbiota richness and more evenly distributed species. In terms of changes in intestinal microbial diversity in patients with IgAV at the genus level, obligate anaerobes such as Bifidobacterium, Prevotella, Coprobacter, Prevotella_9, Blautia, Romboutsia, Parabacteroide, Subdoligranulum, and Roseburia were significantly reduced, and the enrichment of facultative anaerobe was represented by Bacteroides, Lachnoclostridium, and Alistipe.

CONCLUSION

Different bacterial species may be involved in the pathogenesis of different types of IgAV-GI. Differences were observed in the intestinal microbiota between healthy children and children with IgAV.

Spondylodiscitis due to anaerobic bacteria Veillonella parvula: Case report and literature review

Background:

While pyogenic spondylodiscitis due to Gram-positive aerobic bacteria and its treatment is well known, spondylodiscitis caused by anaerobic Gram-negative pathogen is rare. In particular, the spondylodiscitis caused by Veillonella species is an absolute rarity. Thus no established management recommendations exist.

Case Description:

A case report of a 79-year-old man with spondylodiscitis caused by Veillonella parvula with intramuscular abscess collection managed conservatively with stand-alone antibiotic therapy without a spinal stabilization procedure. A review of literature of all reported spondylodiscitis caused by Veillonella species was performed. After 3 week-intravenous therapy with the ceftriaxone in combination with the metronidazole followed by 3 weeks per oral therapy with amoxicillin/clavulanate, the complete recovery of the patient with the V. parvula infection was achieved.

Conclusion:

Treatment of the spondylodiscitis caused by Veillonella species should contain a beta-lactam with beta-lactamase inhibitor or third-generation cephalosporine. Six weeks of treatment seem to be sufficient for the complete recovery of the patient.

Epidural abscess and spondylitis caused by Veillonella parvula in a man on hemodialysis

Veillonella species rarely cause serious infections, but the incidence of infection has been increasing among immunocompromised individuals. This case of an epidural abscess and spondylitis caused by Veillonella parvula in a hemodialysis patient illustrates the importance of performing anaerobic blood culture in immunocompromised patients with signs of infection.

Associations between gut microbiota and thyroidal function status in Chinese patients with Graves' disease

OBJECTIVE

The imbalance of gut microbiota has been linked to manifold endocrine diseases, but the association with Graves' disease (GD) is still unclear. The purpose of this study was to investigate the correlation between human gut microbiota and clinical characteristics and thyroidal functional status of GD.

METHODS

14 healthy volunteers (CG) and 15 patients with primary GD (HG) were recruited as subjects. 16SrDNA high-throughput sequencing was performed on IlluminaMiSeq platform to analyze the characteristics of gut microbiota in patients with GD. Among them, the thyroid function of 13 patients basically recovered after treatment with anti-thyroid drugs (oral administration of Methimazole for 3-5 months). The fecal samples of patients after treatment (TG) were sequenced again, to further explore and investigate the potential relationship between dysbacteriosis and GD.

RESULTS

In terms of alpha diversity index, the observed OTUs, Simpson and Shannon indices of gut microbiota in patients with GD were significantly lower than those in healthy volunteers (P < 0.05).The difference of bacteria species was mainly reflected in the genus level, in which the relative abundance of Lactobacillus, Veillonella and Streptococcus increased significantly in GD. After the improvement of thyroid function, a significant reduction at the genus level were Blautia, Corynebacter, Ruminococcus and Streptococcus, while Phascolarctobacterium increased significantly (P < 0.05). According to Spearman correlation analysis, the correlation between the level of thyrotropin receptor antibody (TRAb) and the relative abundance of Lactobacillus and Ruminococcus was positive, while Synergistetes and Phascolarctobacterium showed a negative correlation with TRAb. Besides, there were highly significant negative correlation between Synergistetes and clinical variables of TRAb, TPOAb and TGAb (P < 0.05, R <  - 0.6).

CONCLUSIONS

This study revealed that functional status and TRAb level in GD were associated with composition and biological function in the gut microbiota, with Synergistetes and Phascolarctobacterium protecting the thyroid probably, while Ruminococcus and Lactobacillus may be novel biomarkers of GD.

Bacteremia caused by Veillonella dispar in an oncological patient

Veillonella dispar is a Gram-negative anaerobic coccus involved in only a few human diseases. We report the second case of bacteremia due to this microorganism in an elderly patient. A 72-year-old man with a history of bladder cancer presented with diarrhea, vomiting, and fever for 48 hours. After the diagnosis of septic shock, four sets of blood cultures were taken, and three of them yielded V. dispar. Resistance to metronidazole, penicillin, and piperacillin-tazobactam was documented. Treatment with clindamycin was started, and the patient was discharged after improvement in his general condition.

Acromioclavicular Septic Arthritis Caused by Veillonella parvula

We hereby report the case of a primary acromioclavicular septic arthritis caused by Veillonella parvula. This bacteria is rare as a pathogen but is well known as a commensal of the lungs, vagina, mouth, and gastrointestinal tract of humans. However, it may turn as an opportunistic pathogen. It was isolated in blood culture and confirmed in biopsy specimen. The patient had complete recovery after surgical washout with second look at postoperative day two and targeted antibiotic treatment.

Identification and phylogenetic analysis of oral Veillonella species isolated from the saliva of Japanese children

Background: As the most frequent infectious disease among children worldwide, dental caries have a strong relationship with oral hygiene status, specifically in the development of infection. However, the study regarding the identification and distribution of oral Veillonella are limited. The oral Veillonella community may affected by the differences in geographical location, age, diet, lifestyle, socio-economic status and oral hygiene status. Here, we studied the oral hygiene status by examining the composition and proportion of oral Veillonella species in saliva of Japanese children.

Methods: Microbial samples collected from 15 Japanese children divided into three oral hygiene groups were cultured under anaerobic conditions after homogenization and dilution, and inoculated onto brain heart infusion and selective medium Veillonella agar. Genomic DNA was extracted from each isolate. Veillonella species were detected by one-step PCR using rpoB species-specific primers. To analyse the phylogenetic properties of the unknown Veillonella strains, PCR amplification and sequence analysis of rpoB were conducted for 10 representative strains.

Results: Although V. rogosae was found as the predominant species among all groups, its prevalence was significantly lower in the children with poor oral hygiene than in those with good oral hygiene. V. parvula was the prevalent species in the poor oral hygiene group. Approximately 10% of the isolated Veillonella strains were not classified to any established species; the phylogenetic analysis showed that they were most closely related to V.infantium

Conclusions: This study demonstrates that the composition and proportion of oral Veillonella species in the saliva of Japanese children is correlated with different oral hygiene status. Changes in detection ratios of V. parvula and V. rogosae can be useful indicators of oral hygiene status. Furthermore, new strains closely related to V. infantium were isolated from the saliva of Japanese children.

Identification and phylogenetic analysis of oral Veillonella species isolated from the saliva of Japanese children

Background: As the most frequent infectious disease among children worldwide, dental caries have a strong relationship with oral hygiene status, specifically in the development of infection. However, the study regarding the identification and distribution of oral Veillonella are limited. The oral Veillonella community may affected by the differences in geographical location, age, diet, lifestyle, socio-economic status and oral hygiene status. Here, we studied the oral hygiene status by examining the composition and proportion of oral Veillonella species in saliva of Japanese children. Methods: Microbial samples collected from 15 Japanese children divided into three oral hygiene groups were cultured under anaerobic conditions after homogenization and dilution, and inoculated onto brain heart infusion and selective medium Veillonella agar. Genomic DNA was extracted from each isolate. Veillonella species were detected by one-step PCR using rpoB species-specific primers. To analyse the phylogenetic properties of the unknown Veillonella strains, PCR amplification and sequence analysis of rpoB were conducted for 10 representative strains. Results: Although V. rogosae was found as the predominant species among all groups, its prevalence was significantly lower in the children with poor oral hygiene than in those with good oral hygiene. V. parvula was the prevalent species in the poor oral hygiene group. Approximately 10% of the isolated Veillonella strains were not classified to any established species; the phylogenetic analysis showed that they were most closely related to V. infantium Conclusions: This study demonstrates that the composition and proportion of oral Veillonella species in the saliva of Japanese children is correlated with different oral hygiene status. Changes in detection ratios of V. parvula and V. rogosae can be useful indicators of oral hygiene status. Furthermore, new strains closely related to V. infantium were isolated from the saliva of Japanese children.

The Impact of Cholecystectomy on the Gut Microbiota: A Case-Control Study

Cholecystectomy alters the bile flow into the intestine and the enterohepatic circulation of the bile acids; this may affect the gut microbiota. We assessed the gut microbiota composition of patients who had undergone cholecystectomy and compared with those who had not. From a cohort of 1463 adult participants who underwent comprehensive health screening examinations, 27 subjects who had undergone cholecystectomy (cholecystectomy group) and 81 age- and sex-matched subjects who had not (control group) were selected. Clinical parameters were collected and compared. Microbial composition was determined by 16S rRNA gene sequencing of DNA extracted from fecal samples. We evaluated differences in the overall microbial composition and in the abundance of taxa. The two groups were comparable with respect to clinical characteristics and laboratory results. The actual number of taxa observed in a sample (observed features) was significantly lower in the cholecystectomy group than in the control group (p = 0.042). The beta diversity of Jaccard distance index was significantly different between the two groups (p = 0.027). Blautia obeum and Veillonella parvula were more abundant in the cholecystectomy group. The difference in the diversity of the gut microbiota between the cholecystectomy and control groups was subtle. However, B. obeum and V. parvula, which have azoreductase activity, were more abundant in the cholecystectomy group. The impact of such changes in the gut microbiota on health remains to be determined.

Veillonella parvula spondylodiscitis

OBJECTIVES

Veillonella parvula is an anaerobic Gram-negative coccus rarely involved in bone and joint infections.

PATIENTS AND METHOD

We report the case of a Veillonella parvula vertebral osteomyelitis (VO) in a female patient without any risk factor.

RESULTS

The 35-year-old patient was immunocompetent and presented with Veillonella parvula VO. She was admitted to hospital for inflammatory lower back pain. The discovertebral sample was positive for Veillonella parvula. Literature data on Veillonella VO is scarce. Reported cases usually occurred in immunocompromised patients. Diagnosis delay can be up to four months. Patients are usually afebrile. Outcome with antimicrobial treatment alone is favorable in half of cases. Other patients must undergo surgery.

CONCLUSIONS

Veillonella VO may occur in immunocompetent patients and have a clinical spectrum of mechanical lower back pain.

Lytic lesions: looking lethal but leaving room for a simple cure? A case of Veillonella spinal osteomyelitis

Introduction. Diagnosing clinically significant infection caused by Veillonella species can be a challenge. Veillonella species are usually found in polymicrobial processes and are often regarded as a contaminant. Additionally, they are slow to grow in culture and this can lead to a delay in diagnosis or a missed diagnosis. Veillonella species rarely cause serious infections, but have been found to cause bacteraemia and osteomyelitis.

Case presentation. A 67-year-old man with a history of treated prostate cancer presented with 2 weeks of progressive lower back pain and weakness. He had no signs or symptoms of active infection. He was found to have multiple lytic lesions in his lumbar spine that were initially suspected to be secondary to metastatic cancer. However, tissue and blood cultures were ultimately consistent with infection by Veillonella species.

Conclusion. This case report highlights the fact that uncommon illnesses can often present like common disease processes. Because of the radiological appearance of the patient’s lesions and his lack of infectious symptoms, a diagnosis of metastatic cancer was initially thought to be likely. Relying on the pathology and culture data, and waiting on the initiation of antimicrobials until the diagnosis was accurately established, were important factors in diagnosing and treating this infection. Veillonella species can be true pathogens when found in isolation and associated with bacteraemia. Additionally, they can cause an indolent infection that can lead to osteomyelitis. Failure to accurately diagnose this infection in a timely manner would have led to ongoing debility and diagnostic uncertainty for this patient.

Osteomyelitis caused by Veillonella species: Case report and review of the literature

Previously, Veillonella species had been considered as nonpathogenic and rarely caused serious infections. We report a case of 25-year-old man with osteomyelitis caused by Veillonella species. He was admitted to the hospital due to an open fracture to the left radial bone caused by industrial washing machine accident, and emergency surgery was performed. However, wound infections occurred one week after the operation. Although Acinetobacter baumannii and Serratia marcescens were cultured from the pus, obligate anaerobic bacteria were not detected at that point. Debridement was repeated and antibiotics were changed according to the result of bacterial culture and drug sensitivity. Despite this, the infection was poorly controlled. On the 5th debridement, granulomatous bone tissues on pseudarthrosis were found for the first time at the infection site. Although no bacteria was detected with aerobic culture, anaerobic incubation revealed Gram-negative cocci which was later identified as Veillonella species by 16S rRNA gene sequence analysis. His condition improved without any additional debridement after adding effective antibiotics against Veillonella species. It is well known that prolonged infection with aerobes consumes oxygen in the infection site and leads the environment to more favorable conditions for anaerobic bacteria, thus we speculated that prolonged infection with bacteria such as S. marcescens induced the favorable environment for Veillonella species. Physicians should realize the importance of anaerobic culture method in routine practice, especially in complicated cases such as the present case. In this article, we reviewed case reports of Veillonella infection and summarized the clinical features of this organism.

Intra-Genomic Heterogeneity in 16S rRNA Genes in Strictly Anaerobic Clinical Isolates from Periodontal Abscesses

BACKGROUND

Members of the genera Prevotella, Veillonella and Fusobacterium are the predominant culturable obligate anaerobic bacteria isolated from periodontal abscesses. When determining the cumulative number of clinical anaerobic isolates from periodontal abscesses, ambiguous or overlapping signals were frequently encountered in 16S rRNA gene sequencing chromatograms, resulting in ambiguous identifications. With the exception of the genus Veillonella, the high intra-chromosomal heterogeneity of rrs genes has not been reported.

METHODS

The 16S rRNA genes of 138 clinical, strictly anaerobic isolates and one reference strain were directly sequenced, and the chromatograms were carefully examined. Gene cloning was performed for 22 typical isolates with doublet sequencing signals for the 16S rRNA genes, and four copies of the rrs-ITS genes of 9 Prevotella intermedia isolates were separately amplified by PCR, sequenced and compared. Five conserved housekeeping genes, hsp60, recA, dnaJ, gyrB1 and rpoB from 89 clinical isolates of Prevotella were also amplified by PCR and sequenced for identification and phylogenetic analysis along with 18 Prevotella reference strains.

RESULTS

Heterogeneity of 16S rRNA genes was apparent in clinical, strictly anaerobic oral bacteria, particularly in the genera Prevotella and Veillonella. One hundred out of 138 anaerobic strains (72%) had intragenomic nucleotide polymorphisms (SNPs) in multiple locations, and 13 strains (9.4%) had intragenomic insertions or deletions in the 16S rRNA gene. In the genera Prevotella and Veillonella, 75% (67/89) and 100% (19/19) of the strains had SNPs in the 16S rRNA gene, respectively. Gene cloning and separate amplifications of four copies of the rrs-ITS genes confirmed that 2 to 4 heterogeneous 16S rRNA copies existed.

CONCLUSION

Sequence alignment of five housekeeping genes revealed that intra-species nucleotide similarities were very high in the genera Prevotella, ranging from 94.3-100%. However, the inter-species similarities were relatively low, ranging from 68.7-97.9%. The housekeeping genes rpoB and gyrB1 were demonstrated to be alternative classification markers to the species level based on intra- and inter-species comparisons, whereas based on phylogenetic tree rpoB proved to be reliable phylogenetic marker for the genus Prevotella.

Non-vertebral Veillonella species septicemia and osteomyelitis in a patient with diabetes: a case report and review of the literature

INTRODUCTION

Veillonella is a nonfermentative, strictly anaerobic, Gram-negative coccus that forms part of the human gastrointestinal tract, mouth and vaginal flora. Like other anaerobic infection, Veillonella species usually are involved in polymicrobial processes, which make it difficult to determine their pathogenic role. Isolation of a clinically significant Veillonella species is rare and V. parvula is the most common one reported to cause infection in humans. The most frequently reported infection caused by V. parvula is osteomyelitis, almost always in association with bacteremia.

CASE PRESENTATION

Here, we describe a rare case of nonvertebral osteomyelitis and septicemia caused by Veillonella species in a 49-year-old Saudi man with diabetes. Initial treatment with ciprofloxacin was associated with treatment failure and poor response. Identification of the organism was essential for the selection of appropriate treatment. There have been only seven previous reports of Veillonella vertebral osteomyelitis and one report of V. parvula foot osteomyelitis with sepsis in the literature. This is the second case of Veillonella nonvertebral osteomyelitis associated with septicemia reported to date.

CONCLUSIONS

Veillonella species should be considered a true pathogen in diabetic patients with osteomyelitis and those with underlying immune suppression, particularly if the organism is isolated from blood. The isolation of those obligate anaerobes from blood may signal the presence of severe underlying disease and the probable need for timely surgical intervention.

Contribution of Veillonella parvula to Pseudomonas aeruginosa-mediated pathogenicity in a murine tumor model system

The recent finding that high numbers of strict anaerobes are present in the respiratory tract of cystic fibrosis (CF) patients has drawn attention to the pathogenic contribution of the CF microbiome to airway disease. In this study, we investigated the specific interactions of the most dominant bacterial CF pathogen, Pseudomonas aeruginosa, with the anaerobic bacterium Veillonella parvula, which has been recovered at comparable cell numbers from the respiratory tract of CF patients. In addition to growth competition experiments, transcriptional profiling, and analyses of biofilm formation by in vitro studies, we used our recently established in vivo murine tumor model to investigate mutual influences of the two pathogens during a biofilm-associated infection process. We found that P. aeruginosa and V. parvula colonized distinct niches within the tumor. Interestingly, significantly higher cell numbers of P. aeruginosa could be recovered from the tumor tissue when mice were coinfected with both bacterial species than when mice were monoinfected with P. aeruginosa. Concordantly, the results of in vivo transcriptional profiling implied that the presence of V. parvula supports P. aeruginosa growth at the site of infection in the host, and the higher P. aeruginosa load correlated with clinical deterioration of the host. Although many challenges must be overcome to dissect the specific interactions of coinfecting bacteria during an infection process, our findings exemplarily demonstrate that the complex interrelations between coinfecting microorganisms and the immune responses determine clinical outcome to a much greater extent than previously anticipated.

Epidural abscess caused by Veillonella parvula: Case report and review of the literature

Veillonella parvula, an anaerobic, Gram-negative coccus is part of the normal flora of the oral, gastrointestinal, respiratory, and genitourinary tracts in humans and animals. We herein present a case of epidural abscess caused by V. parvula in a 68-year-old man with sinus squamous cell carcinoma who presented with a 3-week history of low back pain. Blood and pus cultures were positive for Veillonella spp. After sequencing of the 16S ribosomal DNA, the pathogen was identified as V. parvula. Surgical debridement was performed following which the patient received intravenous administration of amoxicillin/clavulanate. To our knowledge, there are only seven reported cases of spinal infection caused by Veillonella spp. and these are reviewed here.

Acute pyelonephritis and secondary bacteraemia caused by Veillonella during pregnancy

We report a case of pyelonephritis and secondary bacteraemia caused by Veillonella species during pregnancy. Veillonella is part of the normal flora from the oral cavity, gut and vagina. However, because Veillonella is usually isolated from cultures of clinical specimens as part of commensal flora, it is frequently regarded as a contaminant. In the present case, Veillonella was isolated from the patient's urine and blood samples that showed evidence of pyelonephritis and secondary bacteraemia. We found that ureteral stenting is an extremely effective therapeutic option for pregnant woman with hydronephrosis and clear signs and symptoms of urosepsis.

Veillonella spondylodiscitis in a healthy 76-year-old lady

PURPOSE

To report a case of Veillonella spondylodiscitis in a healthy 76-year-old lady.

METHODS

A previously healthy 76-year-old lady presented with worsening axial back pain at the thoracolumbar junction, fever and loss of weight. Examination revealed deep tenderness over the thoracolumbar junction with painful and restricted spinal movements. The lower limb motor power, sensation and reflexes were normal.

RESULTS

Radiographs of the lumbosacral spine showed evidence of spinal instability with lateral translation and loss of disc space at L1-L2. MRI scans revealed fluid intensity within the L1-L2 disc with infective debris elevating the posterior longitudinal ligament and narrowing the spinal canal. Both tissue and blood cultures were positive for the anaerobic organism, Veillonella. A staged anterior-posterior spinal surgery followed by an extended course of antibiotics resulted in the clinical improvement and normalisation of blood parameters. A review of the literature on Veillonella infections is also presented.

CONCLUSION

The aim of this report is to bring Veillonella spondylodiscitis to the attention of spinal surgeons and infectious disease specialists and discuss the management options.

Identification by 16S rRNA gene sequencing of Negativicoccus succinicivorans recovered from the blood of a patient with hemochromatosis and pancreatitis

We describe a case of Negativicoccus succinicivorans bacteremia in an adult man with hemochromatosis and acute pancreatitis. Conventional phenotypic tests and commercial identification systems failed to definitively identify the tiny anaerobic Gram-negative coccus isolated from two sets of blood cultures. The bacterium was identified by 16S rRNA gene sequencing and analysis using the SmartGene Integrated Database Network System software. This is the first published report of the recovery of this organism from a patient with invasive infection.

Intragenomic and intraspecific heterogeneity in rrs may surpass interspecific variability in a natural population of Veillonella

As well as intraspecific heterogeneity, intragenomic heterogeneity between 16S rRNA gene copies has been described for a range of bacteria. Due to the wide use of 16S rRNA gene sequence analysis for taxonomy, identification and metagenomics, evaluating the extent of these heterogeneities in natural populations is an essential prerequisite. We investigated inter- and intragenomic 16S rRNA gene heterogeneity of the variable region V3 in a population of 149 clinical isolates of Veillonella spp. of human origin and in 13 type or reference Veillonella strains using PCR-temporal temperature gel electrophoresis (TTGE). 16S rRNA gene diversity was high in the studied population, as 45 different banding patterns were observed. Intragenomic heterogeneity was demonstrated for 110 (74 %) isolates and 8 (61.5 %) type or reference strains displaying two or three different gene copies. Polymorphic nucleotide positions accounted for 0.5–2.5 % of the sequence and were scattered in helices H16 and H17 of the rRNA molecule. Some of them changed the secondary structure of H17. Phylotaxonomic structure of the population based on the single-copy housekeeping gene rpoB was compared with TTGE patterns. The intragenomic V3 heterogeneity, as well as recombination events between strains or isolates of different rpoB clades, impaired the 16S rRNA-based identification for some Veillonella species. Such approaches should be conducted in other bacterial populations to optimize the interpretation of 16S rRNA gene sequences in taxonomy and/or diversity studies.

Complete genome sequence of Veillonella parvula type strain (Te3)

Veillonella parvula (Veillon and Zuber 1898) Prévot 1933 is the type species of the genus Veillonella in the family Veillonellaceae within the order Clostridiales. The species V. parvula is of interest because it is frequently isolated from dental plaque in the human oral cavity and can cause opportunistic infections. The species is strictly anaerobic and grows as small cocci which usually occur in pairs. Veillonellae are characterized by their unusual metabolism which is centered on the activity of the enzyme methylmalonyl-CoA decarboxylase. Strain Te3^T, the type strain of the species, was isolated from the human intestinal tract. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of a member of the large clostridial family Veillonellaceae, and the 2,132,142 bp long single replicon genome with its 1,859 protein-coding and 61 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

Receptor recognition of and immune intracellular pathways for Veillonella parvula lipopolysaccharide

Veillonella parvula is an anaerobic gram-negative coccus that is part of the normal flora of the animal and human mouth and gastrointestinal and genitourinary tracts. Oral V. parvula is involved in the development of early periodontal disease as well as different types of serious infections. Present data on molecular mechanisms responsible for innate immune response against Veillonella are very scanty. The aim of this study was to investigate the Toll-like receptor (TLR) pathways responsible for V. parvula lipopolysaccharide (LPS) and to identify the intracellular pathways induced by this recognition. V. parvula LPS stimulated tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) release in human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner. Pretreatment of cells with a TLR4 antagonist significantly reduced TNF-alpha and IL-6 production in PBMC stimulated with either Veillonella or Escherichia coli LPS. However, V. parvula LPS was 10- to 100-fold less active than E. coli LPS for cytokine induction. TNF-alpha, IL-1beta, IL-6, and IL-10 were released in wild-type and TLR2(-/-), but not TLR4(-/-), mouse macrophage cultures. V. parvula LPS was able to activate the human PBMC p38 mitogen-activated protein kinase (MAPK). A specific p38 MAPK inhibitor strongly inhibited V. parvula LPS-induced TNF-alpha, IL-1beta, IL-6, and IL-10. In conclusion, V. parvula LPS is able to induce cytokine production in both human and murine in vitro models, although it is less effective than Enterobacteriaceae LPS. V. parvula LPS-stimulated cytokine induction, as well as p38 MAPK activation, are TLR4-dependent features.

Intestinal obstruction associated with chronic peritonitis caused by Sphingomonas paucimobilis

We describe a very rare case of chronic peritonitis with secondary adhesive intestinal obstruction caused by Sphingomonas paucimobilis in a healthy 28-year-old Chinese man. This bacillus has not been described as a cause of spontaneous peritonitis in healthy people. It was an asymptomatic, generalized, and slow-growing peritonitis causing peritoneal adherens and at the end intestinal occlusion that needed surgical adhesiolysis.