Peptostreptococcus anaerobius: Pathogenicity, identification, and antimicrobial susceptibility. Review of monobacterial infections and addition of a case of urinary tract infection directly identified from a urine sample by MALDI-TOF MS.

Peptostreptococcus anaerobius is a gram-positive anaerobic coccus (GPAC) found in the gastrointestinal and vaginal microbiota. The organism is mainly found in polymicrobial and scarcely in monobacterial infections such as prosthetic and native endocarditis. Anaerobic bacteria have rarely been reported as the cause of urinary tract infection (UTI). Although GPAC are susceptible to most antimicrobials used against anaerobic infections, P. anaerobius has shown to be more resistant. Herein, we report a case of UTI caused by P. anaerobius from a 62-year-old man with a history of urological disease. Surprisingly, the microorganism was directly identified by Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) from the urine sample. The isolate was successfully identified by phenotypic methods, MALDI-TOF MS, and 16S rRNA gene sequencing. P. anaerobius showed no ß-lactamase-producing activity, was resistant to penicillin, ampicillin, ciprofloxacin and levofloxacin, and displayed intermediate susceptibility to ampicillin-sulbactam and amoxicillin-clavulanic acid. Successful treatment was achieved with oral amoxicillin-clavulanic acid. Antimicrobial susceptibility testing (AST) should be performed on P. anaerobius isolates due to their unpredictable AST patterns and because empirically administered antimicrobial agents may not be active. This report shows that MALDI-TOF MS, directly used in urine specimens, may be a quick option to diagnose UTI caused by P. anaerobius or other anaerobic bacteria. This review is a compilation of monobacterial infections caused by P. anaerobius published in the literature, their pathogenicity, identification, and data about the antimicrobial susceptibility of P. anaerobius.

A Retrospective Chart Review of Inflamed Epidermal Inclusion Cysts.

BACKGROUND: Epidermal inclusion cysts (EIC) are one of the most common forms of cysts found on and/or underneath the skin. Inflamed EICs typically show signs and symptoms such as pain and erythema, mimicking cutaneous abscess. However, prior studies have demonstrated at least 20% of lesions are culture negative. OBJECTIVE: To determine the rate of culture positivity in mild inflamed epidermal inclusion cysts, in particular to identify whether empiric antibiotics are warranted. METHODS: In a retrospective chart review 76 cases of inflamed EIC that were mild (lacking systemic symptoms) were analyzed who presented to the department of dermatology at Mount Sinai between 2016–2019. RESULTS: Of cultures taken from inflamed cysts, 47% resulted in no bacterial growth or growth of normal flora, 38.4% resulted in growth of aerobic bacteria with methicillin-resistant Staphylococcus aureus (8%), Staphylococcus lugdunensis (5%), and methicillin-sensitive Staphylococcus aureus (13%) predominating, and 9.3% resulting in growth of anaerobic bacteria with Finegoldia magna, Peptostreptococcus, and Cutibacterium acnes presenting. Review of prescribed treatment regimens often involved antibiotic medication, despite a high prevalence of negative culture. CONCLUSIONS: Almost half of cases of mild inflamed EIC (lacking systemic symptoms) cultured will not grow pathogenic bacteria, therefore incision and drainage with culture and appropriate therapy is a viable therapeutic option in uncomplicated inflamed EIC lesions. In this way, over prescription of antibiotics can be minimized. J Drugs Dermatol. 2021;20(2):199-202. doi:10.36849/JDD.5014.

Parvimonas micra, Peptostreptococcus stomatis, Fusobacterium nucleatum and Akkermansia muciniphila as a four-bacteria biomarker panel of colorectal cancer.

Dysbiosis of the gut microbiome has been associated with the pathogenesis of colorectal cancer (CRC). We profiled the microbiome of gut mucosal tissues from 18 CRC patients and 18 non-CRC controls of the UKM Medical Centre (UKMMC), Kuala Lumpur, Malaysia. The results were then validated using a species-specific quantitative PCR in 40 CRC and 20 non-CRC tissues samples from the UMBI-UKMMC Biobank. Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus stomatis and Akkermansia muciniphila were found to be over-represented in our CRC patients compared to non-CRC controls. These four bacteria markers distinguished CRC from controls (AUROC = 0.925) in our validation cohort. We identified bacteria species significantly associated (cut-off value of > 5 fold abundance) with various CRC demographics such as ethnicity, gender and CRC staging; however, due to small sample size of the discovery cohort, these results could not be further verified in our validation cohort. In summary, Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus stomatis and Akkermansia muciniphila were enriched in our local CRC patients. Nevertheless, the roles of these bacteria in CRC initiation and progression remains to be investigated.

Network Analysis of Gut Microbiome and Metabolome to Discover Microbiota-Linked Biomarkers in Patients Affected by Non-Small Cell Lung Cancer.

Several studies in recent times have linked gut microbiome (GM) diversity to the pathogenesis of cancer and its role in disease progression through immune response, inflammation and metabolism modulation. This study focused on the use of network analysis and weighted gene co-expression network analysis (WGCNA) to identify the biological interaction between the gut ecosystem and its metabolites that could impact the immunotherapy response in non-small cell lung cancer (NSCLC) patients undergoing second-line treatment with anti-PD1. Metabolomic data were merged with operational taxonomic units (OTUs) from 16S RNA-targeted metagenomics and classified by chemometric models. The traits considered for the analyses were: (i) condition: disease or control (CTRLs), and (ii) treatment: responder (R) or non-responder (NR). Network analysis indicated that indole and its derivatives, aldehydes and alcohols could play a signaling role in GM functionality. WGCNA generated, instead, strong correlations between short-chain fatty acids (SCFAs) and a healthy GM. Furthermore, commensal bacteria such as Akkermansia muciniphila, Rikenellaceae, Bacteroides, Peptostreptococcaceae, Mogibacteriaceae and Clostridiaceae were found to be more abundant in CTRLs than in NSCLC patients. Our preliminary study demonstrates that the discovery of microbiota-linked biomarkers could provide an indication on the road towards personalized management of NSCLC patients.

Oral microbial profile variation during canine ligature-induced peri-implantitis development.

BACKGROUND: Dental implants have become well-established in oral rehabilitation for fully or partially edentulous patients. However, peri-implantitis often leads to the failure of dental implants. The aim of this study was to understand the core microbiome associated with peri-implantitis and evaluate potential peri-implantitis pathogens based on canine peri-implantitis model. RESULTS: In this study, three beagle dogs were used to build peri-implantitis models with ligature-induced strategy. The peri-implant sulcular fluids were collected at four different phases based on disease severity during the peri-implantitis development. Microbial compositions during peri-implantitis development were monitored and evaluated. The microbes were presented with operational taxonomic unit (OTU) classified at 97% identity of the high-throughput 16S rRNA gene fragments. Microbial diversity and richness varied during peri-implantitis. At the phylum-level, Firmicutes decreased and Bacteroides increased during peri-implantitis development. At the genus-level, Peptostreptococcus decreased and Porphyromonas increased, suggesting peri-implantitis pathogens might be assigned to these two genera. Further species-level and co-occurrence network analyses identified several potential keystone species during peri-implantitis development, and some OTUs were potential peri-implantitis pathogens. CONCLUSION: In summary, canine peri-implantitis models help to identify several potential keystone peri-implantitis associated species. The canine model can give insight into human peri-implantitis associated microbiota.

Enterobacter cloacae Periprosthetic Joint Infection After Bariatric Surgical Anastomotic Leak.

Four weeks after a bilateral total knee arthroplasty (TKA), an immunocompetent, 61-year-old, Caucasian man presented with a periprosthetic joint infection (PJI) of the left knee by Enterobacter cloacae (an enteric bacteria). The most likely source of his infection was due to an anastomotic leak after a bariatric surgery done 6 months before TKA. There is a growing focus on stratifying the risk of PJI after TKA. Hematogenous seeding of enteric bacteria leading to PJI is an unexplored risk that will become more prevalent as bariatric procedures before TKA continue to increase in frequency. We present a patient who demonstrates this PJI risk with a rare microbe (E cloacae).

Treating an intramuscular abscess following toothpick injury in a diabetic patient: A case report and literature review (CARE Complaint).

RATIONALE: Toothpick puncture (TPP) is a penetrating injury that can result in bringing pathogens to the deep space. Such penetrating wounds are typically of pinpoint size with initial symptoms appearing subtle. Consequently, the injury itself is often neglected by patients, or is not detected during physical examinations by medical doctors. Reported complications from such injuries include osteomyelitis and septic arthritis, mostly due to delayed treatment. PATIENT CONCERNS: A diabetic patient aged 83-year-old presented a 2-day history of skin redness, swelling, and tenderness over his forearm following a TPP a week earlier. Laboratory investigations showed leukocytosis with neutrophilic predominance and a high level of C-reactive protein. Before his operation, cultures of aspirated fluid from the injured site revealed the presence of Streptococcus anginosus, Streptococci viridans, Prevotella intermedia, and Pavimonas (Peptostreptococcus) micra. DIAGNOSIS: Intramuscular abscess associated with toothpick injury. INTERVENTIONS: Surgical irrigation with debridement and adjunctive antibiotics of ceftriaxone and clindamycin were given with a satisfactory response. Cultures of debrided tissue showed the presence of P intermedia and P (Peptostreptococcus) micra. OUTCOMES: A split-thickness skin graft was done. Patient was discharged on the 30th postoperative day. LESSONS: Toothpick injury, initial symptoms of which are subtle, can in some cases, lead to serious complications especially when managements are delayed. In such situations (including the present case), surgical irrigation and debridement are administrated for the eradication of infections, removal of potentially retained toothpick, and tissue cultures analyzed. Adjunctive antibiotics is recommended to combat both the aerobic and anaerobic microorganisms of the gastrointestinal tract, skin surface, and oral cavity.

Changes in Microbiota and Development of Nonspecific Inflammation of Genitals in Female C57Bl/6 Mice after Aerosol Infection with Mycobacterium tuberculosis.

Infectious process even at the initial stage after aerosol infection with Mycobacterium tuberculosis induced rapid changes in vaginal microbiota in mice. Rapid decrease in both the quantity and diversity of microbiota was noted, and then, partial recovery of normal flora was observed. Changes in vaginal microbiota was detected as soon as in 3-7 days after lung infection, while inflammatory changes appeared by day 35. At the early stage of infection, no signs of inflammation were observed, neither M. tuberculosis nor its DNA were detected in mouse genital organs.

Infección de prótesis articular por Peptostreptococcus canis y Bacteroides pyogenes / Peptostreptococcus canis and Bacteroides pyogenes prosthetic joint infection

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Association of metformin administration with gut microbiome dysbiosis in healthy volunteers.

BACKGROUND: Metformin is a widely used first-line drug for treatment of type 2 diabetes. Despite its advantages, metformin has variable therapeutic effects, contraindications, and side effects. Here, for the very first time, we investigate the short-term effect of metformin on the composition of healthy human gut microbiota. METHODS: We used an exploratory longitudinal study design in which the first sample from an individual was the control for further samples. Eighteen healthy individuals were treated with metformin (2 × 850 mg) for 7 days. Stool samples were collected at three time points: prior to administration, 24 hours and 7 days after metformin administration. Taxonomic composition of the gut microbiome was analyzed by massive parallel sequencing of 16S rRNA gene (V3 region). RESULTS: There was a significant reduction of inner diversity of gut microbiota observed already 24 hours after metformin administration. We observed an association between the severity of gastrointestinal side effects and the increase in relative abundance of common gut opportunistic pathogen Escherichia-Shigella spp. One week long treatment with metformin was associated with a significant decrease in the families Peptostreptococcaceae and Clostridiaceae_1 and four genera within these families. CONCLUSIONS: Our results are in line with previous findings on the capability of metformin to influence gut microbiota. However, for the first time we provide evidence that metformin has an immediate effect on the gut microbiome in humans. It is likely that this effect results from the increase in abundance of opportunistic pathogens and further triggers the occurrence of side effects associated with the observed dysbiosis. An additional randomized controlled trial would be required in order to reach definitive conclusions, as this is an exploratory study without a placebo control arm. Our findings may be further used to create approaches that improve the tolerability of metformin.

Clostridium difficile and Clostridioides difficile: Two validly published and correct names.

The current status of the names Clostridium difficile and Clostridioides difficile is explained in view of the current confusion about the correct name of this well-known pathogen. Both names have been validly published under the provisions of the Prokaryotic Code and both names can be used.

Subdural empyema caused by Peptostreptococcus sp.: a complication of acute pharyngitis.

Subdural Empyema (ESD) is the collection of purulent fluid that develops between the exterior "dura mater" layer and the middle "arachnoid mater" layer that covers the brain. ESD can be caused by a primary infection located in the paranasal sinuses. In many aerobic and/or anaerobic bacterial cases, hearing or traumatic processes serve as the causative agent. This report presents pharyngitis in a young girl which later developed into a subdural empyema caused by the bacteria Peptostreptococcus sp. The report emphasizes the correct clinical valuation of pharyngitis as a risk factor for developing subdural empyema in children.

Septic arthritis of knee joint due to Parvimonas micra.

Parvimonas species are anaerobic, Gram-positive cocci that are a constituent of normal oral and gastrointestinal flora. We present a case of right knee joint septic arthritis due to Parvimonas micra in an immunocompromised patient. A 61-year-old male renal and pancreatic transplant recipient on immunosuppressive therapy was admitted to our hospital due to intense pain, joint swelling and inability to move his right knee over the past 9 months. After synovial fluid was drawn, cultures were positive for P. micra, an anaerobic pathogen that is part of the flora of the oral cavity. We report a rare causative pathogen for septic arthritis in an immunocompromised patient.

In Vitro Activities of Pexiganan and 10 Comparator Antimicrobials against 502 Anaerobic Isolates Recovered from Skin and Skin Structure Infections.

Pexiganan, a cationic peptide, exhibited a broad range of anti-anaerobic antimicrobial activity. The MIC90s of studied isolates were as follows: Bacteroides fragilis, 16 µg/ml; other B. fragilis group spp., 4 µg/ml; Prevotella and Fusobacterium spp., 32 µg/ml; Porphyromonas spp., 64 µg/ml; Propionibacterium acnes, 4 µg/ml; Eggerthella lenta and Peptostreptococcus anaerobius, 32 µg/ml; other Gram-positive rods and cocci, 4 µg/ml; Clostridium perfringens, 128 µg/ml; and other clostridia, 256 µg/ml. Pexiganan cream shows potential as adjunctive therapy for skin and skin structure infections (SSSIs) involving anaerobes.

Spondylodiscitis due to Parvimonas micra diagnosed by the melting temperature mapping method: a case report.

BACKGROUND: It has been suggested that more than 100 bacterial species can be identified using only seven universal bacterial primer sets in the melting temperature (Tm) mapping method and that these findings can be obtained within 3 h of sterile site collection. CASE PRESENTATION: A 67-year-old Japanese man with type 2 diabetes visited our hospital complaining of progressive lower back pain for 2 months. The patient was suspected to have spondylodiscitis on magnetic resonance imaging of the spine. Blood culture and transcutaneous vertebral biopsy were subsequently performed. Using the Tm mapping method, Parvimonas micra was detected from a transcutaneous vertebral biopsy specimen in 3 h. Gram-positive cocci were also detected by Gram staining and P. micra was identified directly from the anaerobic blood culture by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Four days after admission, the biopsy specimen culture isolate was identified as P. micra. CONCLUSIONS: The Tm mapping method may be useful for the diagnosis of bacterial infections where diagnosis is challenging because of the difficulty of culturing.

Odontogenic orbital abscess with intracranial and pulmonary involvement.

A 58-year-old woman presented to the emergency department with left ptosis and complete ophthalmoplegia. Imaging demonstrated a left orbital abscess. Her past medical history included cavitatory lung disease and "aseptic" meningitis 2 months previously. An anaerobic organism and commensal of the oral flora, Peptostreptococcus sp., was cultured from the orbital abscess. The patient was found to have a carious upper molar with chronic buccal abscess, which was extracted. This case presents an uncommon pathogen arising from an odontogenic infection as the etiology for orbital abscess, cavitatory lung disease, and meningitis in one patient.

Pleural effusion due to Parvimonas micra. A case report and a literature review of 30 cases / Derrame pleural debido a Parvimonas micra. Descripción de un caso y revisión de la literatura de 30 casos

The clinical and microbiological characteristics of infections caused by Parvimonas micra is described, including 30 cases in the literature and a new case handled at the present centre. Out of the 31 patients, 18 were male; mean age at diagnosis was 65.1 ± 13.0 years. Infection site was the vertebral spine in 14 patients and joints and heart valves in 5 each one; pain was present in all patients with articular localization and in almost all patients with vertebral involvement. The diagnosis was obtained from fluid aspirate or drainage in 13 cases and blood cultures in 11. In 8 cases, molecular techniques were also applied. The most frequently used antimicrobials were clindamycin, penicillin, amoxicillin and ceftriaxone. The outcome was positive with the medical treatment in 28 patients. P. micra infections are uncommon and requires a high index of suspicion (AU)

Se describen las características clínicas y microbiológicas de las infecciones causadas por Parvimonas micra, incluyendo 30 casos revisados de la literatura y un nuevo caso tratado en nuestro centro. De los 31 pacientes, 18 eran hombres; la media de edad al diagnóstico fue de 65,1 ± 13,0 años. En 14 pacientes, la localización de la infección fue la columna vertebral, mientras que las articulaciones y las válvulas cardiacas lo fueron en 5 cada una; en todos los pacientes con localización articular hubo dolor, y en caso todos los pacientes con afectación vertebral. El diagnóstico se obtuvo mediante aspiración de líquido o drenaje en 13 casos y mediante hemocultivos en 11. En 8 casos se aplicaron técnicas moleculares. Los antimicrobianos más frecuentemente utilizados fueron clindamicina, penicilina, amoxicilina y ceftriaxona. El pronóstico fue favorable con el tratamiento médico en 28 pacientes. Las infecciones por P. micra son raras y requieren un alto índice de sospecha (AU)

Bacterial communities found in placental tissues are associated with severe chorioamnionitis and adverse birth outcomes.

Preterm birth is a major cause of neonatal mortality and morbidity worldwide. Bacterial infection and the subsequent inflammatory response are recognised as an important cause of preterm birth. It is hypothesised that these organisms ascend the cervical canal, colonise placental tissues, cause chorioamnionitis and in severe cases infect amniotic fluid and the foetus. However, the presence of bacteria within the intrauterine cavity does not always precede chorioamnionitis or preterm birth. Whereas previous studies observing the types of bacteria present have been limited in size and the specificity of a few predetermined organisms, in this study we characterised bacteria found in placental tissues from a cohort of 1391 women in rural Malawi using 16S ribosomal RNA gene sequencing. We found that specific bacteria found concurrently on placental tissues associate with chorioamnionitis and delivery of a smaller newborn. Severe chorioamnionitis was associated with a distinct difference in community members, a higher bacterial load and lower species richness. Furthermore, Sneathia sanguinengens and Peptostreptococcus anaerobius found in both matched participant vaginal and placental samples were associated with a lower newborn length-for-age Z-score. This is the largest study to date to examine the placental microbiome and its impact of birth outcomes. Our results provide data on the role of the vaginal microbiome as a source of placental infection as well as the possibility of therapeutic interventions against targeted organisms during pregnancy.