Peptostreptococcus Species Research Articles

Peptostreptococcus equinus sp. nov., isolated from horse faeces.

A Gram-stain-positive, non-spore-forming, and obligate anaerobic bacteria designated strain CBA3647T was isolated from a horse faecal sample in Jeju, Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CBA3647T formed a distinct phyletic lineage from closely related species within the genus Peptostreptococcus. Based on comparative analysis of 16S rRNA gene sequences, Peptostreptococcus anaerobius ATCC 27337T is most closely related to strain CBA3647T with a 16S rRNA gene similarity of 98.31 %, while similarity to other type strains is below 98.0 %. The genomic DNA G+C content of strain CBA3647T was 30.0 mol%. The digital DNA-DNA hybridization values between strain CBA3647T and the six Peptostreptococcus species were equal to or less than 24 %. Cells were non-motile and oval-shaped cocci with catalase-positive and oxidase-negative activities. Growth occurred at 20-40 °C (optimum, 35 °C), pH 6-8 (optimum, pH 7), and in the presence of 0-2 % (w/v) NaCl (optimum, 1 %). Strain CBA3647T contained C14 : 0 iso and C16 : 0 as major fatty acids. Phenotypic, chemotaxonomic, and molecular properties of strain CBA3647T suggest that it represents a novel species in the genus Peptostreptococcus, which has been named Peptostreptococcus equinus sp. nov. The type strain is CBA3647T (=KACC 22891T= JCM 35846T).

Multi-omic integration of microbiome data for identifying disease-associated modules

Multi-omic studies of the human gut microbiome are crucial for understanding its role in disease across multiple functional layers. Nevertheless, integrating and analyzing such complex datasets poses significant challenges. Most notably, current analysis methods often yield extensive lists of disease-associated features (e.g., species, pathways, or metabolites), without capturing the multi-layered structure of the data. Here, we address this challenge by introducing “MintTea”, an intermediate integration-based approach combining canonical correlation analysis extensions, consensus analysis, and an evaluation protocol. MintTea identifies “disease-associated multi-omic modules”, comprising features from multiple omics that shift in concord and that collectively associate with the disease. Applied to diverse cohorts, MintTea captures modules with high predictive power, significant cross-omic correlations, and alignment with known microbiome-disease associations. For example, analyzing samples from a metabolic syndrome study, MintTea identifies a module with serum glutamate- and TCA cycle-related metabolites, along with bacterial species linked to insulin resistance. In another dataset, MintTea identifies a module associated with late-stage colorectal cancer, including Peptostreptococcus and Gemella species and fecal amino acids, in line with these species’ metabolic activity and their coordinated gradual increase with cancer development. This work demonstrates the potential of advanced integration methods in generating systems-level, multifaceted hypotheses underlying microbiome-disease interactions.

Uterine Commensal Peptostreptococcus Species Contribute to IDO1 Induction in Endometrial Cancer via Indoleacrylic Acid.

Microbial dysbiosis has an increasingly appreciated impact on carcinogenesis, and the cervicovaginal microbiome plays a critical role in microenvironmental inflammation. Here, we investigated the involvement of the female genital tract Peptostreptococcus species in gynecological cancer via indoleacrylic acid (IAA). IAA production from Peptostreptococcus species and the effect of bacterial culture on tumor growth in vivo were examined. The impact of IAA on cytokine production and indoleamine-2,3-dioxygenase 1 (IDO1) expression in an endometrial cancer (EC) cell line, as well as their effect on Treg and Teff cells, and M1 and M2 macrophage populations were examined in EC patients and tumor-grafted mice. Clinically, Peptostreptococcus species abundance, IAA, and IDO1 expression were verified in EC patients. The results showed that IAA production was induced in the uteri of BALB/c nude mice by Peptostreptococcus species transplantation, and the intratumoral injection of a conditioned medium from Peptostreptococcus cultures into tumor-grafted mice promoted tumor growth. IL-10 expression was upregulated by IAA; IFN-γ expression was increased by IL-10. IFN-γ induced IDO1 expression in the EC cell line. The co-culture of IDO1-expressing EC cells with peripheral blood mononuclear cells upregulated the Treg proportion and decreased the M1/M2 ratio. Clinically, P. anaerobius was more abundant amongst the uterine microbiota of EC patients than the control. The IAA, IDO1, and kynurenine/tryptophan ratios were all higher in EC tissue, and the M1/M2 ratio was lower. Our study sheds light on the link between IDO1 induction and uterine Peptostreptococcus dysbiosis and provides a potential rationale for the role of Peptostreptococcus species in immune tolerance induction in type I endometrial cancer.

Antimicrobial susceptibility pattern of bacteria isolated from patients with Otitis externa attending a tertiary health-care institution in Sokoto, Nigeria

Abstract Background: Otitis externa is the inflammation or infection of the skin of the external auditory canal, may be acute, subacute, or chronic and usually manifests by itching of the ear, otalgia, otorrhoea, aural fullness, and hearing loss. The causative agent is usually bacteria and occasionally fungi but may be associated with a variety of noninfective systemic or local dermatological conditions such as eczema, seborrhea, and contact dermatitis. Aim: This study aimed to determine the risk factors, bacterial profile, and antimicrobial susceptibility pattern of the isolates from patients with Otitis externa. Methods: A descriptive cross-sectional hospital-based study was conducted on 100 patients with Otitis externa. The ear discharge specimens were collected and analyzed by standard microbial techniques. The antibiotic susceptibility profiles were determined for 12 different antibiotics by the standard disk diffusion method. Data were analyzed with SPSS version 25 and the P < 0.05 was considered statistically significant. Results: The age of the 100 participants ranges from 4 to 57 years with a mean age of 18.78 ± 10.67 standard deviation, and the commonly affected age group was 11–20 years. Pathogens were isolated from 77 (62.1%) of the patients. The predominant isolate was Pseudomonas aeruginosa 32 (41.6%), followed by Staphylococcus aureus 13 (16.9%), others include Proteus mirabilis 7 (9.0%), Peptostreptococcus species 5 (6.5%), Escherichia coli 4 (5.2%), Streptococcus pneumonia 4 (5.2%), Klebsiella pneumonia 3 (3.9%), Streptococcus pyogenes 3 (3.9%), Enterobacter aerogenes 2 (2.6%), Fusobacterium species 2 (2.6%), and Bacteroides 2 (2.6%). Ofloxacin showed good susceptibility to isolated aerobes 65 (95.6%), followed by gentamicin 52 (76.5%) and ceftriaxone 50 (73.5%). All isolated anaerobes showed 100% susceptibility to metronidazole and clindamycin. Bacterial isolates identified in this study showed a trend of multiple drug susceptibility, majority (70%) being susceptible to three or more antimicrobials. Conclusions: Majority of the bacterial isolates were susceptible to more than one antimicrobial agent, hence efforts to isolate microorganisms and determine the susceptibility pattern should be strengthened to improve the treatment outcome of Otitis externa instead of the usual trend of empirical treatment.

A Comparison between Scaling and Root Planning (SRP), Antibiotic and Diode Laser Application in Treatment of Localized Juvenile Periodontitis (Microscopical Study)

The present study aimed to study different ways for treatment of Localized Juvenile periodontitis, cultural and microscopic results of specimens from base line, appeared the following bacterial strains: Bacteroides gracilis ,Fusobacterium nuclautum, Porphyromonas intermedia, Actinomyces, peptostreptococcus species, eikenella corrodens, streptococcus intermedius, Streptococcus salivaris. Which distribution in 50% gram positive and 50% gram negative. Cultural and microscopical result after ten days of the experimental design appeared significant difference P≥ 0.05, at the SRP group results of microscopic and culturing show Peptostreptoccal species, Prevotella intermedia, Fusobacterium nuclautum, Streptococcus Saliveris. While at the SRP and antibiotic treated group (Doxycyclin 100 mg) the pattern of microbial study appeared the following bacteria: Fusobacterium nucleotum, Peptostreptococcus, Streptococcus salivaris. At the other hand the results of third group SRP and diode Laser appeared no growth of microorganism at all site subjected to Laser 0.8 w, 940 nm for 20 sec after ten days of study.

Characterisation of Anaerobes Isolated from Various Clinical Samples: A Cross-sectional Study

Introduction: Anaerobes are an important cause of infections but are often neglected. These infections can range from simple abscesses to life-threatening infections. The isolation of anaerobes is crucial for administering appropriate antibiotic therapy. Aim: To investigate the profile of anaerobes in various clinical samples, including deep-seated skin and tissue infections, aspirated body fluids, and tissue biopsies. Materials and Methods: A cross-sectional study was conducted on a total of 100 samples at the Department of Microbiology, ABVIMS and Dr RML Hospital, New Delhi, from November 2019 to March 2021. Aspirations from deep-seated abscesses, body fluids, intraoperative samples, and tissue biopsies meeting the criteria for anaerobic culture were included. Simultaneous processing for the detection of aerobes was also performed. Anoxomat III anaerobic culture system was used to create an anaerobic environment. Robertson Cooked Meat (RCM) broth was used, and subculture was conducted on 10% Blood Agar (BA). Presumptive identification was performed using gram stain, catalase test (15% hydrogen peroxide), metronidazole disc (5 µg), special potency disc (vancomycin 5 µg, kanamycin 1000 µg, colistin 10 µg), and aerotolerance test. The Vitek 2 compact ID system was used for the final identification of anaerobes. Statistical Package for Social Sciences (SPSS) software, IBM manufacturer, Chicago, USA, ver 21.0, was utilised. Results: The isolation rate of anaerobes was 17 (17%), with Bacteroides fragilis being the predominant organism (6; 35.29%), followed by Actinomyces (2; 11.76%), Clostridium (2; 11.76%), Peptostreptococcus (2; 11.76%), and Prevotella species (2; 11.76%). Isolation was observed from diverse anatomic sites, with pus aspirates constituting the majority of the isolates (9; 52.94%), followed by brain abscesses (3; 17.65%), liver abscesses, peritoneal fluid (2; 11.76%), and tonsillar abscess (1; 5.89%). Five (29.41%) infections were polymicrobial, while 12 (70.59%) were monomicrobial in nature. Conclusion: Anaerobes are emerging as an important causative agents in a variety of diverse and heterogeneous pyogenic infections. This study demonstrates their isolation from various infection sites. Therefore, routine anaerobic cultures should be conducted alongside aerobic cultures, and the importance of anaerobes in clinical infections should not be underestimated.

Alterations of the vaginal microbiome in healthy pregnant women positive for group B Streptococcus colonization during the third trimester

BackgroundStreptococcus agalactiae or group B Streptococcus (GBS) asymptomatically colonizes the genitourinary tracts of up to 30% of pregnant women. Globally, GBS is an important cause of neonatal morbidity and mortality. GBS has recently been linked to adverse pregnancy outcomes. The potential interactions between GBS and the vaginal microbiome composition remain poorly understood. In addition, little is known about the vaginal microbiota of pregnant Egyptian women.ResultsUsing V3-V4 16S rRNA next-generation sequencing, we examined the vaginal microbiome in GBS culture-positive pregnant women (22) and GBS culture-negative pregnant women (22) during the third trimester in Ismailia, Egypt. According to the alpha-diversity indices, the vaginal microbiome of pregnant GBS culture-positive women was significantly more diverse and less homogenous. The composition of the vaginal microbiome differed significantly based on beta-diversity between GBS culture-positive and culture-negative women. The phylum Firmicutes and the family Lactobacillaceae were significantly more abundant in GBS-negative colonizers. In contrast, the phyla Actinobacteria, Tenericutes, and Proteobacteria and the families Bifidobacteriaceae, Mycoplasmataceae, Streptococcaceae, Corynebacteriaceae, Staphylococcaceae, and Peptostreptococcaceae were significantly more abundant in GBS culture-positive colonizers. On the genus and species levels, Lactobacillus was the only genus detected with significantly higher relative abundance in GBS culture-negative status (88%), and L. iners was the significantly most abundant species. Conversely, GBS-positive carriers exhibited a significant decrease in Lactobacillus abundance (56%). In GBS-positive colonizers, the relative abundance of the genera Ureaplasma, Gardnerella, Streptococcus, Corynebacterium, Staphylococcus, and Peptostreptococcus and the species Peptostreptococcus anaerobius was significantly higher. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to the metabolism of cofactors and vitamins, phosphatidylinositol signaling system, peroxisome, host immune system pathways, and host endocrine system were exclusively enriched among GBS culture-positive microbial communities. However, lipid metabolism KEGG pathways, nucleotide metabolism, xenobiotics biodegradation and metabolism, genetic information processing pathways associated with translation, replication, and repair, and human diseases (Staphylococcus aureus infection) were exclusively enriched in GBS culture-negative communities.ConclusionsUnderstanding how perturbations of the vaginal microbiome contribute to pregnancy complications may result in the development of alternative, targeted prevention strategies to prevent maternal GBS colonization. We hypothesized associations between inferred microbial function and GBS status that would need to be confirmed in larger cohorts.

The Bacterial Compositions of Nasal Septal Abscess in Patients with or without Diabetes.

The nasal septal abscess (NSA) is a rare but potentially fatal disease causing intracranial infection. Treatments for NSA include antibiotics, surgical incision and drainage. Diabetes mellitus (DM) is a risk factor for NSA. Therefore, we assessed the pathogenic bacterial composition of NSA in diabetic patients. We analyzed the Chang Gung Memorial Hospital database to collect 79 NSA patients who received surgical incisions and drainage from 2004 to 2015. We divided them into DM and non-DM groups for analysis. We integrated the bacteria cultured from each patient, listed the top three with the highest frequency and divided the bacterial species into facultative anaerobes or aerobes and anaerobes. The microbiological cultures revealed mono-microbial infection in most of the cases. The top three facultative anaerobes or aerobes with the highest frequency of NSA-DM were Klebsiella pneumoniae (37.5%), methicillin-sensitive Staphylococcus aureus (MSSA; 25%) and methicillin-resistant Staphylococcus aureus (MRSA; 12.5%). The top three for NSA-non-DMs were MSSA (24%), MRSA (20%) and Pseudomonas aeruginosa (16%). The top three anaerobes causing NSA were Prevotella intermedia (25%), Peptostreptococcus species (12.5%) and Propionibacterium acnes (12.5%) in DM patients. The top three in non-DM patients were P. intermedia (25%), P. acnes (16.7%) and Fusobacterium nucleatum (12.5%). When treating NSA in diabetic patients, clinicians should choose empirical antibiotics for K. pneumoniae and P. intermedia, and when treating patients with NSA-non-DM, MSSA and P. intermedia should be considered first.

PYOPERITONEUM SECONDARY TO PYOMETRA RUPTURE IN A CARCINOMA CERVIX PATIENT DUE TO ACTINOMYCES TURICENSIS AND PEPTOSTREPTOCOCCUS ANAEROBIUS : A CASE REPORT

We present a rare case of Pyoperitoneum secondary to Pyometra rupture in a carcinoma cervix patient due to dual pathogens- Actinomyces turicensis and Peptostreptococcus anaerobius. Escherichia coli, Enterococcus species, Bacteroides fragilis and Peptostreptococcus species are among the most common organisms isolated from cases of Pyometra. Though Actinomyces turicensis, a Gram positive bacilli belong to the genus Actinomycetes can be part of the normal microbiome of the genital tract, it has been described as a potential pathogen in genital, skin and soft tissue, urinary tract infections and even bacteraemia. The patient responded well to Metronidazole and beta lactam-beta lactamase inhibitor combinations. Hence the pathogenic role of these pathogens should not be ignored especially in patients who are immunocompromised.

Antibacterial Effect of Longan Extract and Diode Laser Combination on Peptostreptococcus Species in Type 2 Diabetic Patients with Apical Periodontitis - A Pilot Study

Diabetes mellitus is a risk factor for developing periapical infections and increases resistance against pharmacotherapy. Microorganisms are the major cause for periradicular diseases. Peptostreptococcus spp. is the most common bacterial isolate from root canals of primary endodontic infections in diabetic patients. Herbal irrigants are being researched for its efficacy against root canal microorganisms owing to their resistance against commonly used irrigants and medicaments. Longan extract is known for its antimicrobial and antiglycemic action. Diode laser is a newer modality in the disinfection of root canal system. The aim of this study was to assess the antibacterial effect of longan extract (longan fruit extract) and diode laser on Peptostreptococcus species in type 2 diabetic patients with primary endodontic infections using PCR technique. Eleven subjects with type 2 diabetes requiring endodontic treatment were selected for the study based on convenience sampling for a period of 3 months. The preoperative root canal samples were collected after gaining access to the root canal system and initial instrumentation of root canals. Postoperative sample were obtained following a disinfection protocol using 3% NaOCl, 17% EDTA, longan extract as the final irrigant, followed by diode laser irradiation. Both the preoperative and postoperative samples were collected as per Moller’s criteria using sterile paper points. The mean percentage reduction following irrigation of the root canal with longan extract was 71.18% whereas diode laser showed 100% disinfection. In conclusion, the combination of longan extract and diode laser provides an effective mode of root canal disinfection in type 2 diabetic patients with apical periodontitis.

In Vitro Efficacy of Antibiotic Combinations with Carbapenems and Other Agents against Anaerobic Bacteria.

We investigated the in vitro efficacy of combinations of carbapenems with clindamycin (CLDM) and minocycline (MINO) against Bacteroides fragilis and Peptostreptococcus species. We selected the carbapenems imipenem, meropenem, panipenem, doripenem, and biapenem. To evaluate the antibiotic efficacy of these combination regimens, the fractional inhibitory concentration index (FICI) was calculated against clinical isolates. Consequently, combination regimens of each carbapenem with CLDM or MINO showed synergistic or additive effects against 83.3–100.0% and no antagonistic effects against P. anaerobius isolates. However, against the B. fragilis group (B. fragilis, B. thetaiotaomicron, and Parabacteroides distasonis), although the combination with other carbapenems and CLDM or MINO did not show remarkable synergistic effects, the combination regimen of IPM with CLDM or MINO indicated mainly additive antibiotic efficacies (FICIs: >0.5 to ≤1.0) to B. fragilis groups. Then, antagonistic effects were admitted in only 5.6% of B. fragilis groups. The effectiveness of antibiotic combination therapy against pathogenic anaerobes has remained unclear. Then, our results can provide new insights to explore the effective combination regimens against multidrug-resistant anaerobic bacteria as empirical and definitive therapies, while this study used only carbapenem susceptible isolates. Hence, further studies are needed to use highly antibiotic-resistant anaerobic isolates to carbapenems.

Case Report on Pyogenic Liver Abscess

Pyogenic liver abscess PLA is an uncommon cause of hospitalisation where majority of cases are polymicrobial and are most frequently caused by seeding of infection from the biliary system. Herein we describe a case of 80-year-old female patient who presented with upper abdominal pain decreased appetite for one week and multiple episodes of vomiting with the content of blood and food particles. The patient complained of other symptoms including fever and significant weight loss. Anaerobic culture of the patient revealed positive growth results with Isolate 1 Bacteroides fragilis and Isolate 2 Peptostreptococcus species. She was treated with IV antibiotics. A positive response to the therapy was observed and the condition of the patient was stable at the time of discharge.

Oral and gastric microbiome in relation to gastric intestinal metaplasia.

Evidence suggests that Helicobacter pylori plays a role in gastric cancer (GC) initiation. However, epidemiologic studies on the specific role of other bacteria in the development of GC are lacking. We conducted a case-control study of 89 cases with gastric intestinal metaplasia (IM) and 89 matched controls who underwent upper gastrointestinal endoscopy at three sites affiliated with NYU Langone Health. We performed shotgun metagenomic sequencing using oral wash samples from 89 case-control pairs and antral mucosal brushing samples from 55 case-control pairs. We examined the associations of relative abundances of bacterial taxa and functional pathways with IM using conditional logistic regression with and without elastic-net penalty. Compared with controls, oral species Peptostreptococcus stomatis, Johnsonella ignava, Neisseria elongata and Neisseria flavescens were enriched in cases (odds ratios [ORs]=1.29-1.50, P=.004-.01) while Lactobacillus gasseri, Streptococcus mutans, S parasanguinis and S sanguinis were under-represented (ORs=0.66-0.76, P=.006-.042) in cases. Species J ignava and Filifactor alocis in the gastric microbiota were enriched (ORs=3.27 and 1.43, P=.005 and .035, respectively), while S mutans, S parasanguinis and S sanguinis were under-represented (ORs=0.61-0.75, P=.024-.046), in cases compared with controls. The lipopolysaccharide and ubiquinol biosynthesis pathways were more abundant in IM, while the sugar degradation pathways were under-represented in IM. The findings suggest potential roles of certain oral and gastric microbiota, which are correlated with regulation of pathways associated with inflammation, in the development of gastric precancerous lesions.

Evaluation of efficacy of different tooth paste formulations in reducing the oral microbial load - An in vivo study

Introduction and Aim: Toothpastes are the most common preventive means in oral health care. Many commercially available dentifrices claim to have antimicrobial properties, but little research has been conducted to investigate these claims. Therefore, this study was conducted to evaluate the efficacy of different toothpaste formulations in reducing the oral microbial load.
 Methodology: A total of six types of tooth pastes-4 herbal and 2 non-herbal- were assigned to a group of 20 subjects each, who used it for a period of six weeks. During the course of the study, at the end of 1st, 3rd and 6th week, subgingival plaque samples collected were subjected to microbial analysis.
 Results: Microbial analysis identified colonies of organisms such as S. mitis, S. mutans, S. salivarius, Peptostreptococcus species, Prevotella species and Lactobacillus species. Colony forming units (cfu) calculated indicated a reduction in microbial load from 1st to 6th week of use of different tooth paste formulations. However statistical analysis of the results did not show significant differences between the groups (p>0.005).
 Conclusion: The selected tooth paste formulations were effective in controlling the microbial load and therefore contributing to maintain good oral hygiene. However, practicing appropriate oral hygiene measures & brushing technique is of utmost importance in maintaining good oral health than the effectiveness of various ingredients in the toothpastes used.

Identification of Potential Oral Microbial Biomarkers for the Diagnosis of Periodontitis.

Periodontitis is a chronic and multifactorial inflammatory disease that can lead to tooth loss. At present, the diagnosis for periodontitis is primarily based on clinical examination and radiographic parameters. Detecting the periodontal pathogens at the subgingival plaque requires skilled professionals to collect samples. Periodontal pathogens are also detected on various mucous membranes in patients with periodontitis. In this study, we characterized the oral microbiome profiles from buccal mucosa and supragingival space in a total of 272 healthy subjects as a control group, and periodontitis patients as a disease group. We identified 13 phyla, 193 genera, and 527 species and determined periodontitis-associated taxa. Porphyromonas gingivalis, Tannerella forsythia, Treponema denticolar, Filifactor alocis, Porphyromonas endodontalis, Fretibacterium fastiosum and Peptostreptococcus species were significantly increased in both the buccal mucosa and the supragingival space in periodontitis patients. The identified eight periodontitis-associated bacterial species were clinically validated in an independent cohort. We generated the prediction model based on the oral microbiome profiles using five machine learning algorithms, and validated its capability in predicting the status of patients with periodontitis. The results showed that the oral microbiome profiles from buccal mucosa and supragingival space can represent the microbial composition of subgingival plaque and further be utilized to identify potential microbial biomarkers for the diagnosis of periodontitis. Besides, bacterial community interaction network analysis found distinct patterns associated with dysbiosis in periodontitis. In summary, we have identified oral bacterial species from buccal and supragingival sites which can predict subgingival bacterial composition and can be used for early diagnosis of periodontitis. Therefore, our study provides an important basis for developing easy and noninvasive methods to diagnose and monitor periodontitis.

Uterine Commensal <i>Peptostreptococcus</i> Species Contribute to IDO1 Induction in Type I Endometrial Cancer Through the Production of Indoleacrylic Acid

Microbial dysbiosis has an increasingly appreciated impact on carcinogenesis and cervicovaginal microbiome plays a critical role in microenvironmental inflammation. Here we investigated the involvement of the female genital tract microbiome in a gynaecological cancer. We transferred Peptostreptococcus species into the uteri of BALB/c nude mice and observed indoleacrylic acid (IAA) production. Intratumoral injection of conditioned medium from bacterial cultures into tumour-xenografted mice for 2 months promoted tumour growth. IAA upregulated IL-10 expression by M2 macrophages, which increased IFN-γ expression by CD8+ T cells. IFN-γ induced indoleamine-2,3-dioxygenase 1 (IDO1) expression in endometrial cancer (EC) cell line. Co-culture of IDO1-expressing EC cells with peripheral blood mononuclear cells upregulated the proportion of regulatory T cells and decreased the M1/M2 ratio. Importantly, P. anaerobius was more abundant amongst the uterine microbiota of clinical EC patient samples than control samples. IAA, IDO1, and the kynurenine/tryptophan ratio were all higher in EC tissue than in healthy tissue, and the M1/M2 ratio was lower. Thus, we conclude that the overabundance of uterine commensal Peptostreptococcus species in EC induces IDO1 expression by producing IAA. Our study sheds light on the link between IDO1 induction and uterine Peptostreptococcus dysbiosis.

DENTAL INFECTION LEADING TO A PULMONARY CATASTROPHE IN AN IMMUNOCOMPETENT PATIENT

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Necrotizing pneumonia is a rare complication of bacterial lung infection. It is caused by either a virulence factor of the microorganism or a predisposing factor of the host. Nearly 4% of all community acquired pneumonias are necrotizing. Most common pathogens are S. aureus, S. pneumoniae and K. pneumoniae. This disease may cause devastating complications such as diffuse pulmonary inflammation, parapneumonic effusions, empyema, bronchopleural fistula, septic shock, and respiratory failure, making treatment more difficult. Peptostreptococcus species are anaerobic gram-positive coccus, part of normal flora on mouth, skin and soft tissue, bone and joints, gastrointestinal and genitourinary tracts. It can become pathogenic under traumatic or immunosuppressed conditions. They can cause brain, liver and lung abscess, as well as necrotizing infections. CASE PRESENTATION: We present a 32 years-old male patient without comorbidities who complains of right upper quadrant and right hemithorax pain of 5 days evolution. Chest Pain 10/10 intensity, non-radiating, without alleviating or aggravating factors. Due to progressive shortness of breath, tachycardia and fever, he seeks for medical help for evaluation. Physical exam remarkable for acute respiratory distress, decreased breath sounds from mid lung to base on right hemithorax and right upper quadrant tenderness. He also complains about a tooth pain in molar number 2 that is fractured. He had gums edema, erythema without secretions. DISCUSSION: Laboratory workup show leukocytosis with left shift and 22% of bands. New Chest X-Ray showed right costophrenic angle opacification for which Chest CT scan was performed and demonstrate a right large pleural effusion and a small pneumothorax. He developed acute respiratory distress, shortness of breath, hypoactivity, persistent tachycardia and worsening hypoxemia. Right thoracostomy tube was placed, were purulent and fetid fluid was drained; Light’s Criteria consistent with an exudate; cytologic diagnosis shows necrotic material with bacterial colonization with final fluid culture growth of Peptostreptococcus prevotii. Blood cultures also found with same bacteria. HIV and hepatitis panel were negative. Directed antibiotic therapy with piperacillin/tazobactam was ordered. Due to loculated empyema Alteplase and DNAse therapy were given. With the adequate treatment he had resolution of effusion and symptoms. CONCLUSIONS: Empyema with Peptostreptococcus prevotii, which is a local flora of gastrointestinal tract, and could be acquired after a dental infection. Due to the aggressiveness of this conditions and high mortality rate, patient survival is dependent on an early recognition. Medical and surgical intervention with proper antimicrobial therapy has a cure of 90-95% after appropriate management. Physicians should be aware of this entity because mortality can be higher as 75% without adequate management. Reference #1: Tsujimoto N, Saraya T, Light RW, et al. A Simple Method for Differentiating Complicated Parapneumonic Effusion/Empyema from Parapneumonic Effusion Using the Split Pleura Sign and the Amount of Pleural Effusion on Thoracic CT. PLoS One 2015; 10:e0130141. DISCLOSURES: No relevant relationships by Ricardo Bauza Vinas, source=Web Response No relevant relationships by Marlene Farinacci Vilaro, source=Web Response No relevant relationships by Ricardo Fernandez, source=Web Response No relevant relationships by Luis Gerena Montano, source=Web Response

Dynamic immunoglobulin responses to gut bacteria during inflammatory bowel disease

ABSTRACT Aberrant immune responses against gut microbiota are thought to be key drivers of inflammatory bowel disease (IBD) pathogenesis. However, the extent and targets of immunoglobulin (Ig) A versus IgG responses to gut bacteria in IBD and its association with IBD severity is not well understood. Here, we address this by analyzing fecal samples from Crohn’s disease (CD), ulcerative colitis (UC), and Non-IBD patients by flow cytometry for the frequency of bacteria that were endogenously bound with IgA and/or IgG. Assessment of IBD patients from two geographically distinct cohorts revealed increased percentages of IgA- and IgG-bound fecal bacteria compared to non-IBD controls. Notably, the two major subsets of IBD showed distinct patterns of Ig-bound bacteria, with CD activity associated with increases in both IgA and IgG-bound bacteria, whereas UC activity correlated only with increases in IgG-bound bacteria. Analysis of the flow sorted Ig-bound bacterial repertoire by 16S rDNA sequencing revealed taxa that were Ig-bound specifically in IBD. Notably, this included bacteria that are also thought to reside in the oral pharynx, including Gemella, Peptostreptococcus, and Streptococcus species. These data show that the pattern of IgA and IgG binding to fecal bacteria is distinct in UC and CD. In addition, the frequency of Ig-bound fecal bacteria may have potential as a non-invasive biomarker for disease activity. Finally, our results support the hypothesis that immune responses to oral pharyngeal bacteria may play an important role in the pathogenesis of IBD.

High-Throughput Sequencing Analysis of Microbial Profiles in the Dry Socket

The aim of this study was to explore and describe the microbial profiles of dry socket (DS) and identify the key microbial population as a possible disease-related factor. Bacterial samples were collected from patients who underwent surgical mandibular third molar extraction and were divided in 3 groups: the disease (D) group composed of patients who were diagnosed with DS; the treated (T) group composed of patients from the D group who received treatment; and the control (C) group composed of patients who did not have adverse reactions after tooth extraction. Bacterial DNA was extracted and the V3 and V4 hypervariable regions of the bacterial 16S rRNA gene were amplified and subjected to sequencing. Sequence data were analyzed using alpha and beta diversity indices. In total, 772,169 high-quality sequences were detected from 31 samples. Using a 97% similarity level, 531 operational taxonomic units were detected. In addition, 10 phyla, 23 classes, 38 orders, 63 families, and 116 genera were found. Composition of the microbial community in the D group differed considerably from that of the T and C groups. Furthermore, a specific microbial pattern, which included Parvimonas, Peptostreptococcus, Prevotella, Fusobacterium, Slackia, Oribacterium, and Solobacterium species, appeared abundantly in the D group compared with the T and C groups. Moreover, Parvimonas, Peptostreptococcus, Prevotella, and Fusobacterium species had important roles in discriminating the D group from the other 2 groups. These results suggest differences in the microbial community composition among DSs, normal-healing sockets, and post-treated sockets. These results provide better insight into the development of DS and enhance the understanding of DS. Nonetheless, further studies are necessary to investigate and confirm how these differential bacteria contribute to the development of the disease.

Medial pterygoid myositis in a Thoroughbred gelding

SummaryThis case report describes the investigation and treatment of an adult horse with purulent, malodorous exudate originating from a large intermandibular mass. Microbial culture of fluid aspirated from a draining tract yielded Peptostreptococcus and Prevotella species which are usually considered to originate from the oral cavity. Computed tomography (CT) was used to aid in the diagnosis and to allow careful presurgical planning, and the horse underwent successful debridement of the abscess cavity under general anaesthesia. Post‐operatively, the horse developed trismus (reduced opening of the jaws) but repeat CT identified that the surgery site was healing appropriately. It was recommended to continue feeding the horse hay to act as physiotherapy and the masticatory action of the horse subsequently returned to normal.