A case of polymicrobial anaerobic spondylodiscitis due to Parvimonas micra and Fusobacterium nucleatum

Implementation of full-length 16S nanopore sequencing for bacterial identification in a clinical diagnostic setting

This study describes the implementation of 16S nanopore sequencing in a diagnostic lab for pathogen identification without prior enrichment. First, the universality of the test and taxonomic resolution was evaluated for 78 clinically relevant bacteria (69 known and 9 unknown bacterial cultures). Next, the diagnostic value of the test was evaluated based on clinical samples. It was shown that 16S sequencing can be used both for identification of unknown cultures and to find bacteria directly in the clinical sample without cultivation. All culture-positive samples (n=11) tested positive with 16S sequencing directly performed on the sample, but bacteria were found as well in 15/30 culture-negative samples. Pathogenic bacteria were found in a background of commensal flora, and even complex polymicrobial infections could be unraveled. This study demonstrates the feasibility of implementing 16S nanopore sequencing in a clinical diagnostic setting and demonstrates its value for the diagnosis of culture-negative and polymicrobial infections.

Sternoclavicular Septic Arthritis Caused by Parvimonas micra and Fusobacterium nucleatum Infection with Intra-articular Corticosteroid Administration

Sternoclavicular septic arthritis is a rare form of septic arthritis that can lead to fatal complications, such as abscess formation and mediastinitis, in the absence of prompt diagnosis and appropriate treatment. A man in his 40s presented with pain in the right sternoclavicular joint area, and after a joint injection of steroids was administered, he was diagnosed with septic sternoclavicular arthritis caused by Parvimonas micra and Fusobacterium nucleatum. Gram staining of a specimen obtained from the abscess formation area led to early suspicion of anaerobic infection, and appropriate antibiotics were administered.

Spondylodiscitis of lumbar complicated with spinal epidural abscess caused by Parvimonas micra: A case report and literature review

Spinal infection caused by Parvimonas micra (P. micra) is a rare infection. The characteristic imageology includes spondylodiscitis, spondylitis, paravertebral abscess, and epidural abscess. One case of spondylodiscitis of lumbar complicated with spinal epidural abscess caused by P. micra was admitted to the Department of Spinal Surgery, Xiangya Hospital, Central South University on February, 2023. This case is a 60 years old man with lower back pain and left lower limb numbness. MRI showed spondylitis, spondylodiscitis, and epidural abscess. The patient underwent debridement, decompression and fusion surgery. The culture of surgical sample was negative. P. micra was detected by metagenomic next-generation sequencing (mNGS). The postoperative antibiotic treatment included intravenous infusion of linezolid and piperacillin for 1 week, then intravenous infusion of ceftazidime and oral metronidazole for 2 weeks, followed by oral metronidazole and nerofloxacin for 2 weeks. During the follow-up, the lower back pain and left lower limb numbness was complete remission. Spinal infection caused by P. micra is extremely rare, when the culture is negative, mNGS can help the final diagnosis.

Anaerobic Spondylodiscitis caused by Parvimonas Micra in a Rheumatoid Arthritis Patient: Case Report and Review of the Literature

We report the rare case of Parvimonas micra bacteraemia and secondary spondylodiscitis probably triggered by tooth injury in a rheumatoid arthritis patient. Anaerobic bacteria associated spondylodiscitis may evade diagnosis due to atypical clinical presentation usually lacking fever, and the difficulties related to microbiological characterisation of the pathogen. Even though anaerobic spinal infections may constitute <3% of the total, clinical suspicion should remain high, especially in the case of positive history for pre-existing oral cavity or gastrointestinal/gynaecological tract infections.

A rare anaerobic cause of vertebral osteomyelitis and psoas abscess: A case study

Parvimonas micra is an obligate anaerobe that forms part of the normal gastrointestinal flora. The advent of matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF) and 16s ribosomal RNA gene sequencing has led to increased detection of many rare anaerobic isolates, including Parvimonas micra. Typical risk factors for Parvimonas micra bacteremia include dental procedures or spinal instrumentation. Here, we report a case of Parvimonas micra spondylodiscitis and psoas abscess in a patient with no obvious antecedent risk factors and explore the challenges in isolation of the organism from tissue samples.

Pharmacokinetic and pharmacodynamic considerations for optimizing antimicrobial therapy used to treat bone and joint infections: an evidence-based algorithmic approach

INTRODUCTION

Bone and joint infections (BJIs) are a major health concern causing remarkable morbidity and mortality. However, which antimicrobial treatment could be the best according to specific clinical scenarios and/or to the pharmacokinetic/pharmacodynamic (PK/PD) features remains an unmet clinical need. This multidisciplinary opinion article aims to develop evidence-based algorithms for empirical and targeted antibiotic therapy of patients affected by BJIs.

AREAS COVERED

A multidisciplinary team of four experts had several rounds of assessment for developing algorithms devoted to empirical and targeted antimicrobial therapy of BJIs. A literature search was performed on PubMed-MEDLINE (until April 2023) to provide evidence for supporting therapeutic choices. Four different clinical scenarios were structured according to specific infection types (i.e. vertebral osteomyelitis, prosthetic joint infections, infected non-unions and other chronic osteomyelitis, and infectious arthritis), need or not of surgical intervention or revision, isolation or not of clinically relevant bacterial pathogens from blood and/or tissue cultures, and PK/PD features of antibiotics.

EXPERT OPINION

The proposed therapeutic algorithms were based on a multifaceted approach considering the peculiar features of each antibiotic (spectrum of activity, PK/PD properties, bone penetration rate, and anti-biofilm activity), and could be hopefully helpful in improving clinical outcome of BJIs.

Late onset prosthetic joint infection caused by Parvimonas micra

Parvimonas micra (P.micra) is a difficult to culture gram positive anaerobic microorganism, typically found in the human microbiota, specially in the oral cavity. There are limited cases in literature reporting prosthetic joint infection due to this bacteria, although its isolation has been reported in different settings in later years. We present the case of a late onset knee prosthetic joint infection caused by Parvimonas micra in an 87 year old woman treated with antibiotics and two-step surgery with prosthetic material removal, antibiotic-loaded cement spacer placement and new prosthetic material replacement after 2 weeks of intravenous antimicrobial therapy followed by 6 weeks of oral therapy.

Atypical Presentation of Periprosthetic Joint Infection After Total Knee Arthroplasty due to Parvimonas micra

There is limited literature reporting the oral pathogen Parvimonas micra as the causative organism of periprosthetic joint infection. Previous reports demonstrate septic arthritis in native or prosthetic joints due to P. micra in elderly or immunocompromised patients associated with tooth abscess and periodontal disease. Our case report is unique because it describes a healthy individual with recurrent gingivitis developing periprosthetic joint infection after total knee arthroplasty as the result of isolated P. micra. Her clinical symptom presented early and manifested as progressive stiffness only. Timely aspiration resulted in early diagnosis, but the patient still underwent 2-stage revision with a more constrained implant. To prevent the risk of infection by oral pathogens such as P. micra, dental history should be thoroughly investigated, and any lingering periodontal infection should be addressed before any arthroplasty operation.

Osteomyelitis of the Distal Phalanx of the Thumb due to Parvimonas micra and Fusobacterium nucleatum: A Case Report

We herein report a case of osteomyelitis of the distal phalanx of the thumb of a 55-year-old man caused by Parvimonas micra and Fusobacterium nucleatum. Osteomyelitis often occurs in long bones and rarely occurs in the bones of the fingers. In addition, osteomyelitis of the finger frequently occurs after trauma or surgery, and blood-borne infection is very rare. P. micra and F. nucleatum, normal flora of the oral cavity, are very rare pathogenic bacteria of osteomyelitis except in periodontal disease, and there are no previous reports regarding the occurrence of osteomyelitis due to P. micra and F. nucleatum in the finger bones.

An iliopsoas abscess caused by Parvimonas micra: a case report

BACKGROUND

Parvimonas micra, a Gram-positive anaerobic coccus, is a rare pathogen for psoas abscess. We describe a case of a patient with iliopsoas abscess caused by P. micra.

CASE PRESENTATION

An 81-year-old Asian man presented to our department with complaints of fever since the preceding day. Abdominal computed tomography revealed the presence of a low-density mass in the right iliopsoas muscle indicative of a psoas abscess. Computed tomography-guided percutaneous drainage of the psoas abscess was performed. Results of organism cultures of the abscess and blood were positive for P. micra. However, our patient had no known primary focus of infection. On the basis of these findings, a primary psoas abscess caused by P. micra was diagnosed, and treatment with ampicillin/sulbactam 1.5 g, administered intravenously every 8 h, was initiated. By day 7, the patient's white blood cell count normalized. By day 20, his C-reactive protein level was decreased to 0.35 mg/dl.

CONCLUSION

Iliopsoas abscesses caused by anaerobic bacteria are relatively rare, and iliopsoas abscesses caused by P. micra are especially rare. Our patient's case revealed that P. micra can cause iliopsoas abscess. Therefore, clinicians should be aware of the possibility that P. micra may cause iliopsoas abscess.

Parvimonas micra bacteremia following endoscopic retrograde cholangiopancreatography: A new route of infection

Parvimonas micra is an anaerobic, Gram-positive coccus belonging to oral, gastrointestinal and genital flora, rarely causing infections in humans. It was mainly deemed to cause bacteremia, septic bone and cerebral infections in patients which have undergone dental procedures or with suboptimal dental hygiene. We report the first case of Parvimonas micra bacteremia following endoscopic retrograde colangiopancreatography performed due to choledocholithiasis in a patient with good oral health. Identification of P. micra was finally performed by Matrix-assisted laser desorption ionization-time of flight mass spectrometry (VITEK MS system, bioMérieux, Marcy l'Étoile, France). All cases reported in english language of Parvimonas micra infections after medical procedure are reviewed in order to alert clinicians about new possible routes of infection of this emerging pathogen.