Importance of Dialister pneumosintes in human periodontitis

Association of F. alocis and D. pneumosintes with Periodontitis Disease Severity and Red Complex Bacteria

Oral biofilms are considered the principal etiological agent in the development of periodontitis. Novel species that may contribute to periodontitis and dysbiosis have been identified recently. The study aims to evaluate the presence of F. alocis and D. pneumosintes in healthy and diseased patients and their association with clinical parameters and with red complex bacteria. The study included 60 subjects, with 30 patients each in the healthy and periodontitis groups. The clinical parameters were noted, and samples were subjected to DNA extraction followed by a polymerase chain reaction. Statistical analysis was performed using the Graph Pad Prism software. Results: F. alocis and D. pneumosintes were detected at a significantly higher percentage in the periodontitis group compared to the healthy group (p < 0.05). D. pneumosintes was significantly associated with T. forsythia in the periodontitis group (p < 0.05). Both of these organisms were present in sites with higher clinical attachment loss (p < 0.05). This study demonstrated that both F. alocis and D. pneumosintes were detected at a significantly higher percentage in periodontitis subjects and were detected more frequently in sites with a greater clinical attachment loss. It was also evident that both F. alocis and D. pneumosintes can be present independently of other putative periodontal pathogens.

First Exploration of the Altered Microbial Gut-Lung Axis in the Pathogenesis of Human Refractory Chronic Cough

PURPOSE

Cough represents a natural mechanism that plays an important defensive role in the respiratory tract, but in some conditions, it may become persistent, nonproductive, and harmful. In general, refractory chronic cough (RCC) occurs in about 20% of individuals; hence, we aimed to assess the presence of altered gut-lung communication in RCC patients through a compositional and functional characterization of both gut (GM) and oral microbiota (OM).

METHODS

16S rRNA sequencing was used to characterize both GM and OM composition of RCC patients and healthy controls (HC). PICRUST2 assessed functional changes in microbial communities while gas chromatography was used to evaluate fecal short-chain fatty acid levels and serum-free fatty acid (FFA) abundances.

RESULTS

In comparison with HC, RCC patients reported increased saliva alpha-diversity and statistically significant beta-diversity in both GM and OM. Also, a, respectively, significant increased or reduced Firmicutes/Bacteroidota ratio in stool and saliva samples of RCC patients has been shown, in addition to a modification of the abundances of several taxa in both GM and OM. Moreover, a potential fecal over-expression of lipopolysaccharide biosynthesis and lipoic acid metabolism pathways and several differences in serum FFA levels have been reported in RCC patients than in HC.

CONCLUSION

Since differences in both GM and OM of RCC patients have been documented, these findings could provide new information about RCC pathogenesis and also pave the way for the development of novel nutritional or pharmacological interventions for the management of RCC through the restoration of eubiotic gut-lung communication.

A case of bacteremia caused by Dialister micraerophilus with Enterocloster clostridioformis and Eggerthella lenta in a patient with pyometra

BACKGROUND

Infection by Dialister micraerophilus, an obligate anaerobic gram-negative bacillus, has rarely been described, and its clinical characteristics remain unclear.

CASE PRESENTATION

We report a case of bacteremia caused by D. micraerophilus, Enterocloster clostridioformis, and Eggerthella lenta in a 47-year-old woman, associated with pyometra. D. micraerophilus was identified using 16S rRNA gene sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. D. micraerophilus was detected by polymerase chain reaction using D. micraerophilus-specific primers and E. clostridioformis and E. lenta was isolated from the drainage pus sample obtained from the pyometra uterus. The patient achieved a cure after abscess drainage and 2-week antibiotic treatment.

CONCLUSIONS

To the best of our knowledge, this is the first report of D. micraerophilus bacteremia. D. micraerophilus may be associated with gynecological infections. Clinicians should consider both oral and gynecological sites when searching to identify the focus of D. micraerophilus infection.

Quantitative investigation of the bacterial content of periodontal abscess samples by real-time PCR

OBJECTIVES

Periodontal abscesses, which are part of the acute periodontal disease group characterized by the destruction of periodontal tissue with deep periodontal pockets, bleeding on probing, suppuration, and localized pus accumulation, cause rapid destruction of tooth-supporting tissues. This study aimed to evaluate the microbial content of periodontal abscesses by specific and culture-independent qPCR.

METHODS

This study was conducted on 30 volunteers diagnosed with periodontal abscesses and presenting with complaints of localized pain, swelling, and tenderness in the gingiva. Genomic DNA was isolated from the samples taken. Escherichia coli bacteria were used for the standard curve created to calculate the prevalence of target bacteria in the total bacterial load. 16S rRNA Universal primers were used to assess the total bacterial load and prevalence. Bacterial counts were analyzed with Spearman's rank correlation coefficients (ρ) matrix.

RESULTS

From the analysis of Real-Time PCR, Porphyromonas gingivalis (30, 100%), Prevotella intermedia (30, 100%), and Fusobacterium nucleatum (30, 100%) were detected in all samples. Campylobacter rectus (29, 96.6%), Porphyromonas endodontalis (29, 96.6%), Tannerella forsythia (28, 93.3%), Filifactor alocis (28, 93.3%), and Actinomyces naeslundii (28, 93.3%) were also frequently detected.

CONCLUSIONS

Periodontal abscesses were found to be polymicrobial, and not only periodontal pathogens appeared to be associated with the development of periodontal abscesses. The presence, prevalence, and number of Porphyromonas endodontalis and Propionibacterium acnes in the contents of periodontal abscesses were determined for the first time in our study. Further studies are needed to better understand the roles of bacteria in periodontal disease, including abscesses.

Bacteria and macrophages in the tumor microenvironment

Cancer and microbial infections are significant worldwide health challenges. Numerous studies have demonstrated that bacteria may contribute to the emergence of cancer. In this review, we assemble bacterial species discovered in various cancers to describe their variety and specificity. The relationship between bacteria and macrophages in cancer is also highlighted, and we look for ample proof to establish a biological basis for bacterial-induced macrophage polarization. Finally, we quickly go over the potential roles of metabolites, cytokines, and microRNAs in the regulation of the tumor microenvironment by bacterially activated macrophages. The complexity of bacteria and macrophages in cancer will be revealed as we gain a better understanding of their pathogenic mechanisms, which will lead to new therapeutic approaches for both inflammatory illnesses and cancer.

Prevotella genus and its related NOD-like receptor signaling pathway in young males with stage III periodontitis

Background

As periodontitis progresses, the oral microbiota community changes dynamically. In this study, we evaluated the dominant bacteria and their roles in the potential pathway in young males with stage III periodontitis.

Methods

16S rRNA sequencing was performed to evaluate variations in the composition of oral bacteria between males with stage I and III periodontitis and identify the dominant bacteria of each group. Function prediction was obtained based on 16S rRNA sequencing data. The inhibitor of the predominant pathway for stage III periodontitis was used to investigate the role of the dominant bacteria in periodontitis in vivo and in vitro.

Results

Chao1 index, Observed Species and Phylogenetic Diversity (PD) whole tree values were significantly higher in the stage III periodontitis group. β-diversity suggested that samples could be divided according to the stages of periodontitis. The dominant bacteria in stage III periodontitis were Prevotella, Prevotella_7, and Dialister, whereas that in stage I periodontitis was Cardiobacterium. KEGG analysis predicted that variations in the oral microbiome may be related to the NOD-like receptor signaling pathway. The inhibitor of this pathway, NOD-IN-1, decreased P. intermedia -induced Tnf-α mRNA expression and increased P. intermedia -induced Il-6 mRNA expression, consistent with the ELISA results. Immunohistochemistry confirmed the down-regulation of TNF-α and IL-6 expressions by NOD-IN-1 in P. intermedia-induced periodontitis.

Conclusion

The composition of the oral bacteria in young males varied according to the stage of periodontitis. The species richness of oral microtia was greater in young males with stage III periodontitis than those with stage I periodontitis. Prevotella was the dominant bacteria in young males with stage III periodontitis, and inhibition of the NOD-like receptor signaling pathway can decrease the periodontal inflammation induced by P. intermedia.

Classification of salivary bacteriome in asymptomatic COVID-19 cases based on long-read nanopore sequencing

The coronavirus (COVID-19) global pandemic has impacted the health of almost everyone, including changes in their salivary microbiota. Since 2019, there has been an increase in the number of new COVID-19 cases in Thailand. Therefore, COVID-19 active case finding is important for early detection and epidemic control. Moreover, the dynamic changes of salivary bacteriome in asymptomatic COVID-19 cases are largely unknown. This research aimed to investigate and compare the salivary bacteriome and the co-infectious bacterial pathogens in the asymptomatic COVID-19 positive group to the negative group, based on novel nanopore sequencing. This cohort was a cross-sectional study including saliva samples collected from 82 asymptomatic participants (39 COVID-19 positive and 43 COVID-19 negative cases). All samples were sequenced for the full-length bacterial 16S rDNA. The alpha and beta diversity analyses were not significantly different between groups. The three major species in salivary bacteriome including Veillonella parvula, Streptococcus mitis, and Prevotella melaninogenica were observed in both groups. Interestingly, Lautropia mirabilis was a significantly enriched species in the saliva of the asymptomatic COVID-19-positive cases based on linear discriminant analysis effect size (LEfSe) analysis. The results suggested that L. mirabilis was a co-infectious agent in the asymptomatic COVID-19 group. However, the potential role of L. mirabilis should be validated in further experimental studies.

The Urinary Microbiome of Older Adults Residing in a Nursing Home Varies With Duration of Residence and Shows Increases in Potential Pathogens

The community of bacteria that colonize the urinary tract, the urinary microbiome, is hypothesized to influence a wide variety of urinary tract conditions. Older adults who reside in nursing homes are frequently diagnosed and treated for urinary tract conditions such as urinary tract infection. We investigated the urinary microbiome of older adults residing in a nursing home to determine if there are features of the urinary microbiome that are associated with specific conditions and exposure in this population. We were also interested in the stability of urinary microbiome over time and in similarities between the urinary and gastrointestinal microbiome. Urine samples were prospectively collected over a period of 10 months from a cohort of 26 older adults (aged >65 years) residing in a single nursing home located in Central Massachusetts. Serial samples were obtained from 6 individuals over 10 months and 5 participants were concurrently enrolled in a study of the gastrointestinal microbiome. Information collected on participants included demographics, medical history, duration of residence in the nursing home, frailty, dementia symptoms, urinary symptoms, antibiotic treatment, urinary catheterization, and hospitalizations over a 10-month period. Clean catch, midstream urine samples were collected and stored at -80°C. DNA was extracted and 16S rRNA gene sequencing was performed. The length of stay in the nursing facility and the Clinical Frailty Scale correlated with significant changes in microbiome composition. An increase in the relative abundance of a putative urinary pathogen, Aerococcus urinae, was the largest factor influencing change that occurred over the duration of residence.

Lemierre Syndrome Due to Dialister pneumosintes: A Case Report

Although Dialister pneumosintes is a commensal microorganism of the oral cavity, it may sometimes cause severe systemic infections. We report a case of Lemierre syndrome (LS), which developed after D. pneumosintes infection, in a 73-year-old Japanese woman who was admitted to the hospital for throat pain, neck swelling, and fever for 3 days. She had a 3-month history of neglected dental caries, gingivitis, and periodontitis. Physical examination revealed right tonsillar erythema and swelling, and computed tomography (CT) showed peritonsillar and retropharyngeal abscesses. Ampicillin/sulbactam was promptly administered after collecting two sets of blood cultures. Surgical drainage for peritonsillar and retropharyngeal abscesses was also conducted on the second hospital day. Although only commensal oral microflora grew in the culture from the drained pus, Gram-negative bacilli were confirmed in the anaerobic blood cultures. Metronidazole was administered intravenously; however, the fever and neck swelling persisted. Repeat CT performed on the fifth hospital day revealed right internal jugular vein thrombosis, a known complication of tonsillitis and pharyngitis once the infection extends beyond the oropharynx. We diagnosed she had coexisting LS, and anticoagulant therapy was added to her treatment regimen. Her condition improved, and she was discharged after completing 3 weeks of antibiotics. Conventional methods failed to identify the isolated bacterium, and 16S rRNA sequencing ultimately identified it as D. pneumosintes. In a literature review of bacteremia due to D. pneumosintes, poor oral hygiene was considered a probable risk factor for invasive D. pneumosintes infection. We consider this to be the case in our patient who presented with dental caries, gingivitis, and periodontitis. In addition, all cases revealed that the 16S rRNA gene sequencing is useful for identifying this species. Although the diagnosis of LS by physical examination is difficult, physicians should always consider it as a potential complication of infections in the pharyngeal area.

Septic Cavernous Sinus Thrombosis Caused by Dental Infection

Purpose: We report a case of bilateral septic cavernous thrombosis caused by a dental infection.Case summary: A 58-year-old male was transferred to our hospital because of left-sided proptosis and eyelid swelling. The patient had fever and left temporal headache, which did not respond to oral and intravenous antibiotics. After experiencing a tooth injury while chewing hard food 3 months ago, the patient developed toothache and swelling around the tooth for which he did not take any treatment. The patient had left eyelid edema, ptosis, chemosis, and conjunctival congestion. The left eye movements were limited in all directions. Brain magnetic resonance imaging showed dilatation and thrombosis of the left superior ophthalmic vein and thrombosis of bilateral cavernous sinuses. The patient was treated with systemic antibiotics and anticoagulants. The blood culture showed growth of Parvimonas micra and Dialister Pneumosintes, which are common causes of dental infection.Conclusions: Septic thrombosis of the cavernous sinus and superior ophthalmic vein thrombophlebitis can occur due to the spread of dental infection. Prompt diagnosis and treatment are important for rapid resolution of symptoms and good prognosis.

Sinogenic polymicrobial anaerobic orbital cellulitis: the importance of source control and broad empirical antibiotics

A man in his twenties with a history of recurrent sinusitis was urgently referred to the emergency department (ED) by an out-of-hours general practitioner following a 2-day history of increasing right eye pain, redness and swelling after a week of coryzal symptoms. He denied visual impairment and any history of recent dental pain or procedures. Initial assessment in ED noted fever, tachycardia and hypotension. Video consultation with ophthalmologist in the ED identified proptosis, periorbital erythema and chemosis with full eye movement solely affecting the right eye. Visual acuity of 6/6 was confirmed in both eyes. After review by the ear, nose and throat (ENT) team, a diagnosis of sinogenic right orbital cellulitis was made, empirical antibiotics started and care transferred to the ENT team for immediate surgical intervention. 48 hours postoperatively, the patient acutely deteriorated, developing ophthalmoplegia and visual acuity of 6/95 in the right eye. Repeat imaging demonstrated a deteriorating picture and urgent surgery was organised at a neighbouring hospital's specialist ENT unit combined with a change to his antibiotics. On day 4, 1 day following transfer, an anaerobic bacterium, Eggerthia catenaformis, was isolated from blood cultures collected on admission. The patient improved clinically following the second surgery and targeted antimicrobial therapy, eventually being discharged 10 days after initial presentation. In addition to E. catenaformis, the Anaerobic Reference Unit (Cardiff) identified two further anaerobic bacteria, Parvimonas micra and Dialister pneumosintes This paper presents the first documented case of polymicrobial anaerobic orbital cellulitis secondary to acute bacterial sinusitis. Moreover, this case underpins the importance of broad empirical antibiotics coupled with surgical source control to effectively manage a rare but sight-threatening and life-threatening disease.

Gut microbiota alterations in response to sleep length among African-origin adults

Sleep disorders are increasingly being characterized in modern society as contributing to a host of serious medical problems, including obesity and metabolic syndrome. Changes to the microbial community in the human gut have been reportedly associated with many of these cardiometabolic outcomes. In this study, we investigated the impact of sleep length on the gut microbiota in a large cohort of 655 participants of African descent, aged 25-45, from Ghana, South Africa (SA), Jamaica, and the United States (US). The sleep duration was self-reported via a questionnaire. Participants were classified into 3 sleep groups: short (<7hrs), normal (7-<9hrs), and long (≥9hrs). Forty-seven percent of US participants were classified as short sleepers and 88% of SA participants as long sleepers. Gut microbial composition analysis (16S rRNA gene sequencing) revealed that bacterial alpha diversity negatively correlated with sleep length (p<0.05). Furthermore, sleep length significantly contributed to the inter-individual beta diversity dissimilarity in gut microbial composition (p<0.01). Participants with both short and long-sleep durations exhibited significantly higher abundances of several taxonomic features, compared to normal sleep duration participants. The predicted relative proportion of two genes involved in the butyrate synthesis via lysine pathway were enriched in short sleep duration participants. Finally, co-occurrence relationships revealed by network analysis showed unique interactions among the short, normal and long duration sleepers. These results suggest that sleep length in humans may alter gut microbiota by driving population shifts of the whole microbiota and also specific changes in Exact Sequence Variants abundance, which may have implications for chronic inflammation associated diseases. The current findings suggest a possible relationship between disrupted sleep patterns and the composition of the gut microbiota. Prospective investigations in larger and more prolonged sleep researches and causally experimental studies are needed to confirm these findings, investigate the underlying mechanism and determine whether improving microbial homeostasis may buffer against sleep-related health decline in humans.

Diverse bacterial profile in extraradicular biofilms and periradicular lesions associated with persistent apical periodontitis

AIM

To characterize the bacterial community present in the extraradicular biofilm and periradicular lesions associated with persistent apical periodontitis.

METHODOLOGY

Eighteen adult patients who presented with persistent periradicular lesions after root canal treatment and scheduled for endodontic surgery were selected. During surgery, extraradicular samples of biofilms and periradicular lesions were collected. Ten pairs of periradicular lesions and extraradicular biofilm samples were randomly selected for ribosomal 16S rRNA cloning and sequencing. A Wilcoxon's rank-sum test was used to compare total bacterial counts and the levels of individual genera and species between the two groups (P < 0.05).

RESULTS

Overall, seventy-three phylotypes belonging to six different phyla were identified from 1000 sequenced clones. Mogibacterium timidum, Streptococcus intermedius and Enterococcus faecalis predominated in both extraradicular biofilm and periapical lesions. Propionibacterium propionicus, Abiotrophia adiacens, Peptostreptococcus prevotii, Campylobacter gracilis and Pseudomonas aeruginosa were found in significantly higher levels in the extraradicular biofilm than periapical lesions, whilst Parvimonas micra and Atopobium rimae were more abundant in periapical lesions (P < 0.05).

CONCLUSIONS

The microbial profile of extraradicular biofilms differed from periapical lesions, indicating the presence of diverse bacterial populations in these regions. Several genera and species were significantly associated with the formation of extraradicular biofilms.

Severe Pneumonia and Sepsis Caused by Dialister pneumosintes in an Adolescent

Background: Dialister pneumosintes (D. pneumosintes) is known to cause dental, periodontal or sinus infections. To date, the pathogen has only been described in a small number of cases with a severe infection. Case report: We describe the clinical case of a 13-year-old, obese female patient that presented with acute respiratory failure and sepsis. A CT-scan showed extensive bilateral patchy areas, subpleural and peribronchovascular consolidations with surrounding ground-glass opacity, extensive consolidations in the lower lobes of both lungs matching to a severe pneumonia and clinically emerging acute respiratory distress syndrome. Moreover, it showed extensive sinusitis of the right sinus frontalis, maxillaris and right cellulae ethmoidales. D. pneumosintes was isolated from an anaerobic blood culture obtained at admission. The antibiotic treatment included piperacillin/tazobactam and oral switch to ampicillin/sulbactam plus ciprofloxacin. Conclusions: We describe the first adolescent with severe systemic D. pneumosintes infection. Since the pathogen is difficult to culture the systemic virulence remains unclear. This work aims to sensitize health care specialists to consider D. pneumosintes infection in patients with periodontal or sinusal infection.

Bacterial community structure alterations within the colorectal cancer gut microbiome

BACKGROUND

Colorectal cancer is a leading cause of cancer-related deaths worldwide. The human gut microbiome has become an active area of research for understanding the initiation, progression, and treatment of colorectal cancer. Despite multiple studies having found significant alterations in the carriage of specific bacteria within the gut microbiome of colorectal cancer patients, no single bacterium has been unequivocally connected to all cases. Whether alterations in species carriages are the cause or outcome of cancer formation is still unclear, but what is clear is that focus should be placed on understanding changes to the bacterial community structure within the cancer-associated gut microbiome.

RESULTS

By applying a novel set of analyses on 252 previously published whole-genome shotgun sequenced fecal samples from healthy and late-stage colorectal cancer subjects, we identify taxonomic, functional, and structural changes within the cancer-associated human gut microbiome. Bacterial association networks constructed from these data exhibited widespread differences in the underlying bacterial community structure between healthy and colorectal cancer associated gut microbiomes. Within the cancer-associated ecosystem, bacterial species were found to form associations with other species that are taxonomically and functionally dissimilar to themselves, as well as form modules functionally geared towards potential changes in the tumor-associated ecosystem. Bacterial community profiling of these samples revealed a significant increase in species diversity within the cancer-associated gut microbiome, and an elevated relative abundance of species classified as originating from the oral microbiome including, but not limited to, Fusobacterium nucleatum, Peptostreptococcus stomatis, Gemella morbillorum, and Parvimonas micra. Differential abundance analyses of community functional capabilities revealed an elevation in functions linked to virulence factors and peptide degradation, and a reduction in functions involved in amino-acid biosynthesis within the colorectal cancer gut microbiome.

CONCLUSIONS

We utilize whole-genome shotgun sequenced fecal samples provided from a large cohort of late-stage colorectal cancer and healthy subjects to identify a number of potentially important taxonomic, functional, and structural alterations occurring within the colorectal cancer associated gut microbiome. Our analyses indicate that the cancer-associated ecosystem influences bacterial partner selection in the native microbiota, and we highlight specific oral bacteria and their associations as potentially relevant towards aiding tumor progression.

A Case of Dialister pneumosintes Bacteremia-Associated Neck and Mediastinal Abscess

BACKGROUND Dialister pneumosintes is a suspected periodontal pathogen. It can affect different parts of the body either by hematogenous transmission or regional spread. Here, we report a case of 30-year-old previously healthy woman diagnosed with mediastinal and neck abscess caused by this pathogen. CASE REPORT A 30-year-old woman presented with a 1-day history of fever, vomiting, and diarrhea. She was on her last dose of a 2-week course of oral antibiotic for suspected dental abscess. On admission, parenteral broad-spectrum antibiotic was started for sepsis of unknown source. Because of intermittent spike of high temperature despite being on an antibiotic, cross-sectional imaging was performed, which revealed a superior mediastinal abscess with extension in the neck. She was referred to the ENT surgeon for incision and drainage of the collection. However, the procedure was complicated by injury to the right internal jugular vein. Her postoperative period was also convoluted with the development of pulmonary embolism, followed by deep vein thrombosis of the right upper limb. Her pus polymerase chain reaction test detected 16s rRNA gene, suggestive of gram-negative anaerobic bacilli, and anaerobic blood culture grew Dialister pneumosintes. After a prolonged course of illness and antibiotic treatment, she recovered well, and now is back to her normal activities. CONCLUSIONS Potential life-threatening complications may develop from periodontal infection by this microorganism. In patients being treated for sepsis of unknown origin, not responding to antibiotic treatment, and with a history of recent periodontal infection, a deep-seated abscess needs to be considered.

Gastric cancer: a comprehensive review of current and future treatment strategies

Gastric cancer remains a major unmet clinical problem with over 1 million new cases worldwide. It is the fourth most commonly occurring cancer in men and the seventh most commonly occurring cancer in women. A major fraction of gastric cancer has been linked to variety of pathogenic infections including but not limited to Helicobacter pylori (H. pylori) or Epstein Barr virus (EBV). Strategies are being pursued to prevent gastric cancer development such as H. pylori eradication, which has helped to prevent significant proportion of gastric cancer. Today, treatments have helped to manage this disease and the 5-year survival for stage IA and IB tumors treated with surgery are between 60 and 80%. However, patients with stage III tumors undergoing surgery have a dismal 5-year survival rate between 18 and 50% depending on the dataset. These figures indicate the need for more effective molecularly driven treatment strategies. This review discusses the molecular profile of gastric tumors, the success, and challenges with available therapeutic targets along with newer biomarkers and emerging targets.

Effect of oral consumption of capsules containing Lactobacillus paracasei LPC-S01 on the vaginal microbiota of healthy adult women: a randomized, placebo-controlled, double-blind crossover study

Oral consumption of probiotics is practical and can be an effective solution to preserve vaginal eubiosis. Here, we studied the ability of orally administered Lactobacillus paracasei LPC-S01 (DSM 26760) to affect the composition of the vaginal microbiota and colonize the vaginal mucosa in nondiseased adult women. A total of 40 volunteers took oral probiotic (24 billion CFU) or placebo capsules daily for 4 weeks, and after a 4-week washout, they switched to placebo or probiotic capsules according to the crossover design. A total of 23 volunteers completed the study according to the protocol. Before and after capsule ingestion, vaginal swabs were collected for qPCR quantification to detect L. paracasei LPC-S01 and for 16S rRNA gene sequencing. Vaginal swabs were grouped according to their bacterial taxonomic structure into nine community state types (CSTs), four of which were dominated by lactobacilli. Lactobacillus paracasei LPC-S01 was detected in the vagina of two participants. Statistical modeling (including linear mixed-effects model analysis) demonstrated that daily intake of probiotic capsules reduced the relative abundance of Gardnerella spp. Quantitative PCR with Gardnerella vaginalis primers confirmed this result. Considering the pathogenic nature of G. vaginalis, these results suggest a potential positive effect of this probiotic capsule on the vaginal microbial ecosystem.

Characterization and Antimicrobial Susceptibility of Pathogens Associated with Periodontal Abscess

Knowledge of microbial composition and antimicrobials' susceptibility to periodontal abscesses is vital for their successful treatment. The current study aims to provide a thorough overview of the clinical and microbial features of periodontal abscesses of the local community. The study was carried out at Rehman College of Dentistry, Peshawar, Pakistan between December 2019 to March 2020. Clinical measurements and microbial samples were collected from 45 subjects. Microbial samples were anaerobically cultured for the growth of selected bacterial species. E-test was used to assess the susceptibility of bacterial species grown from the patient samples to amoxicillin, azithromycin, metronidazole, and tetracycline. The majority of affected patients had preexisting chronic periodontitis. All abscesses clinically demonstrated bleeding on probing and suppuration. The periodontal abscess was most commonly associated with lower incisors and canines, followed by lower molars and then upper incisor and canine teeth. Fusobacterium spp. (73%) was the most frequently detected species followed by Prevotella intermedia/nigrescens (65%), Porphyromonas gingivalis (46%) and Aggregatibacter actinomycetemcomitans (24%). The detected clinical isolates of certain bacteria demonstrated resistance to all tested antibiotics except azithromycin. We conclude that Fusobacterium spp., P. intermedia/nigrescens, P. gingivalis, C. rectus, T. forsythia and A. actinomycetemcomitans are closely associated with periodontal abscess. Bacterial species associated with periodontal abscess demonstrated some level of antimicrobial resistance to amoxicillin, metronidazole and tetracycline while antibiotic resistance to azithromycin could not be demonstrated.

Identification of multidimensional Boolean patterns in microbial communities

BACKGROUND

Identification of complex multidimensional interaction patterns within microbial communities is the key to understand, modulate, and design beneficial microbiomes. Every community has members that fulfill an essential function affecting multiple other community members through secondary metabolism. Since microbial community members are often simultaneously involved in multiple relations, not all interaction patterns for such microorganisms are expected to exhibit a visually uninterrupted pattern. As a result, such relations cannot be detected using traditional correlation, mutual information, principal coordinate analysis, or covariation-based network inference approaches.

RESULTS

We present a novel pattern-specific method to quantify the strength and estimate the statistical significance of two-dimensional co-presence, co-exclusion, and one-way relation patterns between abundance profiles of two organisms as well as extend this approach to allow search and visualize three-, four-, and higher dimensional patterns. The proposed approach has been tested using 2380 microbiome samples from the Human Microbiome Project resulting in body site-specific networks of statistically significant 2D patterns as well as revealed the presence of 3D patterns in the Human Microbiome Project data.

CONCLUSIONS

The presented study suggested that search for Boolean patterns in the microbial abundance data needs to be pattern specific. The reported presence of multidimensional patterns (which cannot be reduced to a combination of two-dimensional patterns) suggests that multidimensional (multi-organism) relations may play important roles in the organization of microbial communities, and their detection (and appropriate visualization) may lead to a deeper understanding of the organization and dynamics of microbial communities. Video Abstract.

Alterations of Gut Microbiome in Tibetan Patients With Coronary Heart Disease

Coronary heart disease (CHD) is closely related to gut microbiota, which may be significantly affected by ethnicity and the environment. Knowledge regarding the gut microbiome of Tibetan CHD patients living in the Qinghai–Tibet Plateau is very limited. In this study, we characterized the physiological parameters and gut microbiota from 23 healthy Tibetans (HT), 18 CHD patients, and 12 patients with non-stenosis coronary heart disease (NCHD). We analyzed the alterations of the gut microbiome in CHD patients and investigated the relationship between these alterations and the pathological indicators. We found no changes in trimethylamine N-oxide, however, a significant increase in lipopolysaccharides and white blood cells, and a decrease in high-density lipoprotein were observed in the blood of CHD patients, compared to that in the HT group. The gut microbiota of the NCHD group had a significantly higher Shannon index than that of the HT group. Adonis analysis showed that both microbial compositions and functions of the three groups were significantly separated. The Dialister genus was significantly lower and Blautia, Desulfovibrio, and Succinivibrio were significantly higher in abundance in CHD patients compared with the HT group, and the changes were significantly correlated with physiological indexes, such as increased lipopolysaccharides. Moreover, enrichment of genes decreased in four pathways of amino acid metabolism, such as arginine biosynthesis and histidine metabolism, although two lipid metabolism pathways, including fatty acid degradation and arachidonic acid metabolism, increased in the CHD group. Additionally, occupation and a family history of CHD were shown to be risk factors and affected the gut microbiota in Tibetans. Our study will provide insights into the understanding of CHD, leading to better diagnosis and treatment of Tibetan patients.

Effect of aeration mode on aerosol characteristics from the same wastewater treatment plant

Aeration and mechanical agitation are the main drivers of aerosol generation in wastewater treatment plants (WWTPs). However, the effect of aeration mode on aerosol characteristics remains poorly understood. In this study, horizontal rotor aeration and fine bubble aeration in the same WWTP were selected to identify the effect on the emission, size distribution, microbial and chemical composition. For bacteria, fungi, Enterobacteriaceae, Staphylococcus aureus, and Pseudomonas aeruginosa in aerosols, the horizontal rotor aeration had higher contributions to the emissions than the fine bubble aeration. Horizontal rotor aeration generated a more coarse fraction (size > 7 μm) and a comparable respirable fraction (RF; size < 3.3 μm) compared with those of fine bubble aeration. More types of potential pathogens were generated by horizontal rotor aeration. The most easily aerosolized genera generated by horizontal rotor aeration and fine bubble aeration, were Trichosporon and Mycobacterium, with the aerosolization factors of 633.70 and 192.56, respectively. For Cl^-, SO₄^2-, NO₃^-, Zn, Ba, Cd, Sc, V, Rb, Ca, K, Ca, K, Mg, Na and Si in the aerosols, the contributions of fine bubble aeration were higher than those of horizontal rotor aeration. Due to the aerosol specialty from the different aeration modes, targeted manipulations should be employed to reduce the exposure risks.

Effect of different Aggregatibacter actinomycetemcomitans strains on dual-species biofilms formed with Porphyromonas gingivalis or Dialister pneumosintes

There are five evolutionarily divergent clades of Aggregatibacter actinomycetemcomitans, with possible differences in phenotype and virulence potential among strains. This study examined the formation of biofilm by each of 11 distinct strains of A. actinomycetemcomitans, alone or after coculture with two species of oral bacteria (Porphyromonas gingivalis ATCC33277 or Dialister pneumosintes ATCC33048). Confocal laser scanning microscopy (CLSM) and electron microscopy were used to characterize the dual-species biofilms of interest. A reduction in dual-species A. actinomycetemcomitans-P. gingivalis biofilms was observed for A. actinomycetemcomitans RHAA1, suggesting an antagonistic relationship. The amounts of dual-species A. actinomycetemcomitans-D. pneumosintes biofilms were either increased or decreased in some - but not all - strains, indicative of strain-specific phenotypes. The CLSM analyses confirmed the existence of an antagonistic relationship between A. actinomycetemcomitans D7S-1 and P. gingivalis ATCC33277, and a synergistic relationship between A. actinomycetemcomitans D7S-1 and D. pneumosintes ATCC33048. The electron microscopy analyses revealed distinct morphological features of A. actinomycetemcomitans D7S-1 and D. pneumosintes ATCC33048 dual-species biofilms. The results indicate that the relationship between A. actinomycetemcomitans and oral bacteria may vary among strains, which could lead to distinct strain-specific patterns of niche sharing in subgingival microbiota.

Filifactor alocis and Dialister pneumosintes in a Mexican population affected by periodontitis and rheumatoid arthritis: An exploratory study

Filifactor alocis and Dialister pneumosintes have been associated with the initiation and progression of periodontitis (PE). We determined and compared the frequency of both bacteria in patients with PE, rheumatoid arthritis (RA), and PE/RA simultaneously. Detection was performed by polymerase chain reaction in the subgingival biofilm. Bacteria were more frequent in patients with PE, and clinical periodontal parameters such as pocket depth (PD) and clinical attachment loss (CAL) were significantly higher in patients with PE/RA. F. alocis and D. pneumosintes could influence PD and CAL, hence participating in the initiation and progression of PE in patients with RA.

MicroPro: using metagenomic unmapped reads to provide insights into human microbiota and disease associations

We develop a metagenomic data analysis pipeline, MicroPro, that takes into account all reads from known and unknown microbial organisms and associates viruses with complex diseases. We utilize MicroPro to analyze four metagenomic datasets relating to colorectal cancer, type 2 diabetes, and liver cirrhosis and show that including reads from unknown organisms significantly increases the prediction accuracy of the disease status for three of the four datasets. We identify new microbial organisms associated with these diseases and show viruses play important prediction roles in colorectal cancer and liver cirrhosis, but not in type 2 diabetes. MicroPro is freely available at https://github.com/zifanzhu/MicroPro .

Whole metagenomic shotgun sequencing of the subgingival microbiome of diabetics and non-diabetics with different periodontal conditions

OBJECTIVE

The aim of this study was to use high-resolution whole metagenomic shotgun sequencing to characterize the subgingival microbiome of patients with/without type 2 Diabetes Mellitus and with/without periodontitis.

DESIGN

Twelve subjects, falling into one of the four study groups based on the presence/absence of poorly controlled type 2 Diabetes Mellitus and moderate-severe periodontitis, were selected. For each eligible subject, subgingival plaque samples were collected at 4 sites, all representative of the periodontal condition of the individual (i.e., non-bleeding sulci in subjects without a history of periodontitis, bleeding pockets in patients with moderate-severe periodontitis). The subgingival microbiome was evaluated using high-resolution whole metagenomic shotgun sequencing.

RESULTS

The results showed that: (i) the presence of type 2 Diabetes Mellitus and/or periodontitis were associated with a tendency of the subgingival microbiome to decrease in richness and diversity; (ii) the presence of type 2 Diabetes Mellitus was not associated with significant differences in the relative abundance of one or more species in patients either with or without periodontitis; (iii) the presence of periodontitis was associated with a significantly higher relative abundance of Anaerolineaceae bacterium oral taxon 439 in type 2 Diabetes Mellitus patients.

CONCLUSIONS

Whole metagenomic shotgun sequencing of the subgingival microbiome was extremely effective in the detection of low-abundant taxon. Our results point out a significantly higher relative abundance of Anaerolineaceae bacterium oral taxon 439 in patients with moderate to severe periodontitis vs patients without history of periodontitis, which was maintained when the comparison was restricted to type 2 diabetics.

Hepatic abscess due to Dialister pneumosintes - A case report

Dialister pneumosintes is an obligate anaerobic Gram-negative rod associated with infections of the oral cavity. We report on a previously healthy, 51-year-old woman who presented with a liver abscess caused by Dialister pneumosintes as a complication of a dental abscess. The microorganism was identified by using a broad-range bacterial 16S rRNA gene PCR in the liver exudate. The patient was cured after abscess drainage and 4-week antibiotic treatment. Our case highlights the importance of a good history and physical examination when taking care of patients admitted for pyogenic liver abscess.

Changes in gut microbiota and plasma inflammatory factors across the stages of colorectal tumorigenesis: a case-control study

Background

Colorectal cancer (CRC) is a common malignant gastrointestinal tumor. In China, CRC is the 5th most commonly diagnosed cancer. The vast majority of CRC cases are sporadic and evolve with the adenoma-carcinoma sequence. There is mounting evidence indicating that gut microbiota and inflammation play important roles in the development of CRC although study results are not entirely consistent. In the current study, we investigated the changes in the CRC-associated bacteria and plasma inflammatory factors and their relationships based on data from a case-control study of Han Chinese. We included 130 initially diagnosed CRC patients, 88 advanced colorectal adenoma patients (A-CRA), 62 patients with benign intestinal polyps and 130 controls.

Results

Fecal microbiota composition was obtained using 16S ribosomal DNA (16S rDNA) sequencing. PCOA analysis showed structural differences in microbiota among the four study groups (P = 0.001, Unweighted Unifrac). Twenty-four CRC-associated bacteria were selected by a two-step statistical method and significant correlations were observed within these microbes. CRC-associated bacteria were found to change with the degree of malignancy. Plasma C-reactive protein (CRP) and soluble tumor necrosis factor II (sTNFR-II) displayed significant differences among the four study groups and increased with adenoma-carcinoma sequence. The correlations of CRP and sTNFR-II with several CRC-associated microbes were also explored.

Conclusions

CRC-associated species and plasma inflammatory factors tended to change along the adenoma-carcinoma sequence. Several CRC-associated bacteria were correlated with CRP and sTNFR-II. It is likely that gut microbiome and inflammation gradually form a microenvironment that is associated with CRC development.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1232-6) contains supplementary material, which is available to authorized users.

Gut Microbial Carbohydrate Metabolism Hinders Weight Loss in Overweight Adults Undergoing Lifestyle Intervention With a Volumetric Diet

The rising incidence of obesity requires the reevaluation of our current therapeutic strategies to optimize patient outcomes. The objective of this study was to determine whether compositional and functional characteristics of the gut microbiota in adults predict responses to a comprehensive lifestyle intervention program in overweight and obese adults. We recruited 26 participants from the Mayo Clinic Obesity Treatment Research Program between August 6, 2013, and September 12, 2013, to participate in a lifestyle intervention program for weight loss. Adults aged 18 to 65 years with a body mass index of 27 to 39.9 kg/m² and able to provide informed consent were included in the study. Fecal stool samples were obtained at baseline and after 3 months. Loss of at least 5% of baseline weight after 3 months was defined as success. Clinical characteristics and gut microbial composition and function were compared between those who achieved at least 5% and those who achieved less than 5% weight loss. After 3 months, 9 of 26 participants lost at least 5% of their weight. The mean weight loss was 7.89 kg (95% CI, 6.46-9.32 kg) in the success group and 1.51 kg (95% CI, 0.52-2.49 kg) in the less than 5% weight loss group. An increased abundance of Phascolarctobacterium was associated with success. In contrast, an increased abundance of Dialister and of genes encoding gut microbial carbohydrate-active enzymes was associated with failure to lose 5% body weight. A gut microbiota with increased capability for carbohydrate metabolism appears to be associated with decreased weight loss in overweight and obese patients undergoing a lifestyle intervention program.

Intracranial subdural abscess with polymicrobial infections due to frontal sinusitis in an adolescent: life-threatening complication of a common disease

Intracranial abscess is one of the most serious complications of frontal sinusitis, particularly among adolescents, even in the absence of odontogenic infection. Polymicrobial infections due to anaerobes are common. Because antibiotic therapy alone is usually ineffective, early endoscopic sinus surgery is the key for infection control and good clinical outcomes.

Effects of Acarbose on the Gut Microbiota of Prediabetic Patients: A Randomized, Double-blind, Controlled Crossover Trial

INTRODUCTION

The α-glucosidase inhibitor acarbose is an efficacious medicine for the treatment and prevention of type 2 diabetes mellitus (T2DM). However, the response of gut microbiota to acarbose is important, as the microbiota may have a critical role in the development of metabolic diseases, and acarbose is metabolized exclusively within the gastrointestinal tract. We explored the changes in the proportion and diversity of gut microbiota before and after treatment with acarbose in patients with prediabetes.

METHODS

We designed a randomized, double-blind, controlled crossover trial in which 52 Chinese patients with prediabetes by an oral glucose tolerance test (OGTT) with a BMI of 18-35 kg/m² were randomly allocated to treatment with acarbose or placebo. Gut microbiota characterizations were determined with 16S rDNA-based high-throughput sequencing.

RESULTS

Of the 52 participants who entered the study, 40 (76.9%) completed the protocol. On the basis of the operational taxonomic unit (OTU) profiles, a total of 107 OTUs were significantly altered after acarbose treatment, with 76 (71%) assigned to the order of Clostridiales. Ruminococcaceae (15 OTUs) and Lachnospiraceae (22 OTUs) decreased in response to acarbose, and 48 OTUs increased by 12.8-fold, including Lactobacillaceae (8 of 9 belonging to Lactobacillus), Ruminococcaceae (6 of 11 belonging to Faecalibacterium), and Veillonellaceae (8 of 15 belonging to Dialister). At genera level, five flourished after treatment with acarbose, including Lactobacillus and Dialister, while Butyricicoccus, Phascolarctobacterium, and Ruminococcus were inhibited.

CONCLUSION

This study suggests that the benefits of acarbose for T2DM may correlate with the selective modulation of the gut microbiota.

TRIAL REGISTRATION

Chinese Clinical Trial Register number, ChiCTR-TTRCC-13004112.

Coexisting pulmonary haemorrhage and venous thrombosis: a tricky but novel case

We present a case of Lemierre's disease complicated by pulmonary artery pseudoaneurysm. A previously well woman aged 43 years presented with a history of a sore throat and worsening dyspnoea. She was diagnosed with a severe cavitating bilateral pneumonia complicated by internal jugular vein thrombosis consistent with a diagnosis of Lemierre's disease. She had an episode of massive haemoptysis which was confirmed to be due to a pulmonary artery pseudoaneurysm which required radiologically guided embolisation. She then required surgical decortication for bilateral empyemata. Blood cultures revealed growth of Slackia exigua, an organism yet to be linked with both of these complications concurrently. We believe this to be a novel case of this bacterium causing thrombosis and haemorrhage.

A case of bacteremia caused by Dialister pneumosintes and Slackia exigua in a patient with periapical abscess

Dialister pneumosintes and Slackia exigua are both obligatory anaerobe and known to be associated with periodontal diseases and other oral infection. We report a case of blood stream infection caused by D. pneumosintes and S. exigua. This occurred in a 78-year-old female patient that presented with general weakness and fever. We revealed that she had a periapical abscess. The blood culture was positive for D. pneumosintes and S. exigua; however, identifying them was challenging. Ultimately, 16S rRNA sequencing was used to identify the organisms. The patient recovered after being treated with ceftriaxone and clindamycin. To the best of our knowledge, this is the first report of bacteremia caused by mixed infection of D. pneumosintes and S. exigua.

Exploring salivary microbiota in AIDS patients with different periodontal statuses using 454 GS-FLX Titanium pyrosequencing

Patients with acquired immunodeficiency syndrome (AIDS) are at high risk of opportunistic infections. Oral manifestations have been associated with the level of immunosuppression, these include periodontal diseases, and understanding the microbial populations in the oral cavity is crucial for clinical management. The aim of this study was to examine the salivary bacterial diversity in patients newly admitted to the AIDS ward of the Public Health Clinical Center (China). Saliva samples were collected from 15 patients with AIDS who were randomly recruited between December 2013 and March 2014. Extracted DNA was used as template to amplify bacterial 16S rRNA. Sequencing of the amplicon library was performed using a 454 GS-FLX Titanium sequencing platform. Reads were optimized and clustered into operational taxonomic units for further analysis. A total of 10 bacterial phyla (106 genera) were detected. Firmicutes, Bacteroidetes, and Proteobacteria were preponderant in the salivary microbiota in AIDS patients. The pathogen, Capnocytophaga sp., and others not considered pathogenic such as Neisseria elongata, Streptococcus mitis, and Mycoplasma salivarium but which may be opportunistic infective agents were detected. Dialister pneumosintes, Eubacterium infirmum, Rothia mucilaginosa, and Treponema parvum were preponderant in AIDS patients with periodontitis. Patients with necrotic periodontitis had a distinct salivary bacterial profile from those with chronic periodontitis. This is the first study using advanced sequencing techniques focused on hospitalized AIDS patients showing the diversity of their salivary microbiota.

Dialister pneumosintes bacteremia caused by dental caries and sinusitis

A 62-year-old Japanese woman was hospitalized at the Department of Senology for positive signals on two sets of blood cultures obtained in the Emergency Department. The initial physical examination with enhanced computed tomography of the chest and abdomen did not identify the infectious source. Dialister pneumosintes was identified on 16S rRNA sequencing, and dental caries with sinusitis were subsequently diagnosed based on a dental examination and magnetic resonance imaging. History taking with respect to dental hygiene and oral examinations should be performed in daily clinical practice, especially in immunosuppressed patients.

Microbiologic profile of endodontic infections from HIV- and HIV+ patients using multiple-displacement amplification and checkerboard DNA-DNA hybridization

OBJECTIVE

To compare the microbiota of endodontic infections in necrotic pulp from HIV-negative and HIV-positive subjects.

MATERIALS AND METHODS

Root canal samples from necrotic pulp were collected from 40 HIV- and 20 HIV+ subjects. Pulps were amplified using multiple displacement amplification (MDA). Then, checkerboard DNA-DNA hybridization was employed to assess the levels of 107 microbial taxa. The percentage of DNA probe count and the percentage of teeth colonized by each test species were investigated. Significant differences between groups regarding proportions of taxa and prevalence of the test species were sought using the Mann-Whitney test and the Chi-square analysis, respectively.

RESULTS

The most prevalent taxa detected were Dialister pneumosintes, Stenotrophomonas maltophilia, Streptococcus sobrinus, Corynebacterium diphteriae, and Helicobacter pylori among HIV- subjects and D. pneumosintes, Prevotella tannerae, Porphyromonas gingivalis, Parvimonas micra, Prevotella nigrescens, and Corynebacterium diphtheriae among HIV+ individuals. D. pneumosintes, C. diphtheria, and C. albicans were the most abundant species in the HIV- group, whereas the predominant taxa in HIV+ samples were P. tannerae, D. pneumosintes and Olsenella uli. P. tannerae, O. uli, Veilonella dispar, Bacteroides fragilis, and Actinomyces meyeri were significantly more abundant in HIV+ samples.

CONCLUSIONS

There were significant differences in the prevalence and proportions of specific microbial taxa between HIV- and HIV+ individuals. The root canal microbiota may represent a reservoir of important oral and medical pathogens, mainly in HIV+ individuals.

Does routine analysis of subgingival microbiota in periodontitis contribute to patient benefit?

In clinical periodontology it is common practice to sample subgingival plaque from periodontitis patients and to search for the presence of alleged periodontal pathogens using routine laboratory techniques such as culture, DNA-DNA hybridization or real-time PCR. Usually, special attention is given to the recognition of 'red complex' microorganisms and to Aggregatibacter actinomycetemcomitans. Recently, molecular open-ended techniques have been introduced which are distinct from the more 'classical' approaches in that they do not preselect for certain species. In this study, we investigated to what extent the outcome of these techniques has changed our insight into the composition of the subgingival microbiota and whether this has consequences on clinical decision making. The open-ended approaches showed that the composition of subgingival plaque is much more complex than previously thought. Next to the 'classical' putative periodontal pathogens, several non-culturable and fastidious species are now recognized as being associated with periodontitis, thus enlarging the group of suspected periodontal pathogens. We conclude that routine analyses of subgingival plaque in the clinic are not necessarily of benefit to the patient.

Antimicrobial susceptibilities and clinical sources of Dialister species

Seventy-four strains representing the four species of the genus Dialister were isolated from various clinical samples. Dialister pneumosintes and Dialister micraerophilus were the two mainly encountered species. Fifty-five isolates were tested against 14 antimicrobial agents. Decreased susceptibilities to piperacillin, metronidazole, macrolides, fluoroquinolones, and rifampin were demonstrated. The clinical impact of these decreased susceptibilities remains to be investigated but should prompt microbiologists to perform antimicrobial susceptibility testing for clinically important Dialister spp.

Detection of Dialister pneumosintes in the subgingival biofilm of subjects with periodontal disease

Dialister pneumosintes has been indicated as a potentially new periodontopathic species. This study evaluated the prevalence of this microorganism in saliva and subgingival biofilm from subjects with different periodontal conditions. Subgingival biofilm and saliva samples from 48 subjects with periodontal health (PH) and 116 patients with chronic periodontitis (CP) were obtained. DNA was extracted from the samples and the presence of D. pneumosintes was determined by PCR. Differences in clinical parameters and frequency of D. pneumosintes between groups were sought by Mann-Whitney, Chi-square and Fisher's exact tests. Overall, D. pneumosintes was detected in 47.8% of the biofilm samples, but only in 3% of saliva samples. CP patients presented a significantly greater mean prevalence of this species in sites with periodontal health and periodontal infection (43.5+/-7.4% and 62.1+/-6.4%, respectively) than PH subjects (29.4+/-7.9%) (Mann-Whitney; p<0.01). Moreover, significant associations between the prevalence of D. pneumosintes and pocket depth (p=0.001), attachment loss (p=0.001) and bleeding on probing (GLM, p=0.014) were observed after adjusting for age and gender. These findings corroborate the association of D. pneumosintes with periodontitis.

Occurrence of Periodontopathic and Superinfecting Bacteria in Chronic and Aggressive Periodontitis Subjects in a Colombian Population

BACKGROUND

Differences in the composition of subgingival microbiota in periodontitis have been observed in different geographic locations. Some of these microbial differences could have clinical significance. This study describes clinical parameters and the composition of the subgingival microbiota in chronic periodontitis (CP) and aggressive periodontitis (AgP) patients in a Colombian population.

METHODS

Clinical parameters (probing depth, clinical attachment level, bleeding on probing, and plaque index) and plaque samples from 68 CP, 12 AgP, and 30 periodontally healthy subjects were analyzed. Subgingival samples were processed using culture, biochemical tests, and polymerase chain reaction for the detection of periodontal and superinfecting pathogens. The analysis of variance, chi(2), and Kruskal-Wallis tests were used to evaluate differences between groups for clinical parameters and microbiologic composition (P <or=0.05).

RESULTS

Clinical parameters were significantly increased in CP and AgP patients compared to healthy subjects (P <0.001), but no differences were found between periodontitis groups. Porphyromonas gingivalis, Tannerella forsythensis, and Eikenella corrodens showed higher frequencies in AgP compared to CP and healthy subjects (P <0.05). Extension (localized and generalized) of the periodontal destruction had no effect on the composition of the subgingival microbiota. Gram-negative enteric rods were more frequent in AgP patients (P <0.01).

CONCLUSIONS

This study demonstrated a high prevalence of P. gingivalis, T. forsythensis, and E. corrodens in AgP patients. Gram-negative enteric rods were frequent in AgP and CP patients. Differences in the composition of subgingival microbiota in periodontitis patients need to be taken into account when considering the best therapeutic approach for each individual, including the use of antibiotics.

Isolation of Dialister pneumosintes isolated from a bacteremia of vaginal origin

In this report, we review one case of bacteremia infection due to Dialister pneumosintes. The patient was admitted in post-partum with vaginosis and suppurative thrombosis of the ovarian veina. D. pneumosintes was isolated in pure culture from the three blood culture flasks. Identification of this bacterium was difficult and requires the amplification and partial sequencing of the 16S rRNA gene. The patients had favorable outcome after antibiotic treatment.