Oesophageal pleural fistula presenting with Parvimonas micra infection causing cervical and brain abscesses

Parvimonas micra orbital cellulitis complicated with cerebral venous thrombosis and mycotic aneurysm

Parvimonas micra is a gram-positive anaerobic coccus typically found in the human oral cavity, upper respiratory tract and gastrointestinal system. It occasionally causes intra-abdominal abscesses, spondylodiscitis and other infections. There are very few case reports on mycotic aneurysm related to P. micra We describe a rare case of P. micra orbital cellulitis complicated with meningitis, cerebral venous thrombosis and internal carotid artery mycotic aneurysm, which was successfully treated with the combination of endovascular therapy and antibiotics. Additionally, the patient received 6 months of anticoagulation therapy for cerebral venous thrombosis.

Severe pneumonia with empyema caused by Parvimonas micra and Streptococcus constellatus co-infection: a case report

Empyema is a common complication of pneumonia, caused by the accumulation of purulent exudate due to pathogenic bacteria invading the pleural cavity. Parvimonas micra and Streptococcus constellatus are pathogens that rarely cause pneumonia with empyema. Herein, a case of severe empyema caused by these two pathogens, confirmed by metagenomic next-generation sequencing (mNGS) of pleural effusion cultures, is reported. A male Chinese patient in his late sixties presented with wheezing, cough, sputum expectoration, and fever. Blood and sputum cultures were negative for pathogens, but the pleural effusion culture was positive for S. constellatus, and was also found to contain P. micra, confirmed by mNGS. The patient's symptoms improved after treatment with cefoperazone/sulbactam and moxifloxacin. Pneumonia caused by P. micra and S. constellatus is rare; however, coinfection with these pathogens may cause severe pneumonia, with or without empyema.

Brain abscess caused by Parvimonas micra: A rare case report and literature review

Brain abscesses mostly develop due to direct infection caused by a nearby infectious lesion or hematogenous spread and are rarely caused by an odontogenic infection. We report a 47-year-old woman who presented with high fever, disturbed consciousness, headache, and neck pain. Imaging studies revealed a ring-shaped enhanced mass in the left frontal lobe causing a mass effect and midline shift. Magnetic resonance spectroscopy revealed a peak alanine concentration of 1.5 ppm. Supraorbital keyhole surgery with abscess removal was performed, and a bacterial culture confirmed a diagnosis of Parvimonas micra infection. After undergoing 6-week antibiotic treatment, the patient's symptoms resolved completely. No recurrence of abscess was observed during the follow-up period. Although brain abscess caused by P. micra has rarely been reported, an odontogenic origin should be investigated, especially when a patient has a history of periodontal infection or tooth extraction.

Destructive osteomyelitis involving Parvimonas micra and Campylobacter rectus

We present a rare case of destructive osteomyelitis of the sternum caused by Parvimonas micra and Campylobacter rectus. A previously healthy female patient in her 40s presented to the emergency department due to a spontaneous rupture of an abscess located to the chest wall. Imaging confirmed abscess formation with osteomyelitis of the sternum. Emergent surgical debridement was performed, blood and bone cultures were taken and the patient received antibiotic treatment. Cultures of the bone and deep tissue revealed infection with Parvimonas micra and Campylobacter rectus, both being members of the oral flora and associated with chronic periodontitis. Receiving targeted antibiotic treatment, our patient made a quick recovery. After treatment of the osteomyelitis, our patient was referred to the dentist where chronic periodontitis could be confirmed. Invasive infections with Parvimonas micra and Campylobacter rectus are rare. Investigation of a dental origin is crucial to prevent recurrent infections.

Iatrogenic Esophagopleural Fistula After the Management of Acute Variceal Hemorrhage With Minnesota Tube Placement

An esophagopleural fistula (EPF) is a rare condition. EPFs are typically of spontaneous, iatrogenic, or neoplastic origin. A 50-year-old man with hepatitis C and alcoholic cirrhosis presented with a history of recurrent variceal hemorrhage requiring esophageal banding, Minnesota tube placement, and a transjugular intrahepatic portosystemic shunt. His hospital course after esophageal perforation and EPF was complicated by acute respiratory failure and empyema, necessitating intubation and thoracostomy tube placement. To the best of our knowledge, this is the first reported case of EPF secondary to Minnesota tube placement. The EPF completely healed after endoscopic repair.

A tale of two unusual anaerobic bacterial infections in an immunocompetent man: A case report and literature review

We report a case of an immunocompetent man who presented with Desulfovibrio fairfieldensis bacteremia, followed by an epidural abscess due to Parvimonas micra. Only few cases have described unique clinical features related to both organisms, and this report illustrates two distinct sequential, if not concurrent, syndromes due to these anaerobes.

Characterization of medical relevant anaerobic microorganisms by isothermal microcalorimetry

Detection of anaerobe bacteria by culture methods requires appropriate media, special growth conditions, additional detection techniques and it typically takes several days. Therefore, anaerobes are often missed in patient specimens under routine culture conditions. Microcalorimetry may provide a simple and accurate real-time method for faster and better detection of anaerobes. An isothermal calorimeter which detect minimal changes of temperature over time was used for the calorimetric experiments. In order to find optimal growth conditions, seven reference or clinical strains of medical relevant anaerobe bacteria were tested under different circumstances. First, the strains were tested with different growth media. After determining the optimal medium for each strain, the gas phase was modified by adding 3 mL or 4 mL medium, to evaluate growth under conditions with less oxygen. Cooked Meat Medium was best supporting growth of the tested strains, including Cutibacterium acnes, Fusobacterium nucleatum, Finegoldia magna, Parvimonas micra, Bacteroides fragilis and Actinomyces odontolyticus, followed by thioglycolate. The best medium to detect Clostridioides difficile was H-Medium. All tested strains showed better growth in 4 mL medium than in 3 mL. The detection time ranged between 10 and 72 h. Our results demonstrated that the sensitivity and the detection time of anaerobe bacteria can be improved by isothermal calorimetry with optimization of growth conditions. Therefore, calorimetric detection, a practical, quick and easy-to-do method, has the potential to replace current microbiological methods.

Distinct Clinical Pathology and Microbiota in Chronic Rhinosinusitis With Nasal Polyps Endotypes

OBJECTIVES/HYPOTHESIS

Eosinophilic and noneosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP and NECRSwNP) show distinguished clinical pathology, but their underlying mechanism remains unclear. We aimed to investigate the clinical, hematological, and histopathological changes in chronic rhinosinusitis with nasal polyps (CRSwNP) endotypes and its association with microbiota.

STUDY DESIGN

A comparative cross-sectional study.

METHODS

A comparative study of 46 patients with CRSwNP (34.69 ± 16.39 years old) who underwent endoscopic sinus surgery were recruited and subdivided into ECRSwNP and NECRSwNP groups based on eosinophilic tissue inflammation; 12 healthy controls were also included. A structured histopathological analysis was conducted, and complete blood count was determined in patients. Endoscopic-guided middle meatus swabs and fecal samples were collected from the patients and controls and subsequently subjected to 16S rRNA gene sequencing on Illumina MiSeq.

RESULTS

Compared to NECRSwNP, ECRSwNP showed a statistically significant increase in the computed tomography score, endoscopic score, blood eosinophil percentage, tissue eosinophil count, inflammation degree, subepithelial edema, and eosinophil aggregation. Airway microbiota communities differed among the three groups. The abundance of Moraxella and Parvimonas was significantly higher in the ECRSwNP group. Distinct microbiota dysbiosis in CRSwNP endotypes was found to be correlated with different clinical pathologies. Moreover, the gut microbiota in ECRSwNP and NECRSwNP showed dysbiosis, that is, significant decrease in the abundance of Actinobacteria in the former and significant increase in the abundance of Enterobacterales and several genera in NECRSwNP.

CONCLUSIONS

Significant clinical pathology and microbiota changes were evident in patients with ECRSwNP and NECRSwNP. Distinct microbiota dysbiosis was correlated with different clinical pathologies. Understanding these differences may improve the prognosis and treatment of chronic rhinosinusitis.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E34-E44, 2021.

Clinical characteristics of bloodstream infection by Parvimonas micra: retrospective case series and literature review

Background

Gram-positive anaerobic (GPA) bacteria inhabit different parts of the human body as commensals but can also cause bacteremia. In this retrospective observational study, we analyzed GPA bacteremia pathogens before (2013–2015) and after (2016–2018) the introduction of the matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS).

Method

We conducted a retrospective observational study by searching the microbiology database to identify all positive GPA blood cultures of patients with GPA bacteremia diagnosed using the new technique, MALDI-TOF MS, between January 1, 2016 and December 31, 2018; and using a conventional phenotypic method between January 1, 2013 and December 31, 2015 at a single tertiary center in Japan. Parvimonas micra (P. micra) (17.5%) was the second most frequently identified GPA (MALDI-TOF MS); we then retrospectively reviewed electronic medical records for 25 P. micra bacteremia cases at our hospital. We also conducted a literature review of published cases in PubMed from January 1, 1980, until December 31, 2019; 27 cases were retrieved.

Results

Most cases of P. micra bacteremia were identified after 2015, both, at our institute and from the literature review. They were of mostly elderly patients and had comorbid conditions (malignancies and diabetes). In our cases, laryngeal pharynx (7/25, 28%) and gastrointestinal tract (GIT; 6/25, 24%) were identified as the most likely sources of bacteremia; however, the infection source was not identified in 9 cases (36%). P. micra bacteremia were frequently associated with spondylodiscitis (29.6%), oropharyngeal infection (25.9%), intra-abdominal abscess (14.8%), infective endocarditis (11.1%), septic pulmonary emboli (11.1%), and GIT infection (11.1%) in the literature review. Almost all cases were treated successfully with antibiotics and by abscess drainage. The 30-day mortalities were 4 and 3.7% for our cases and the literature cases, respectively.

Conclusions

Infection sites of P. micra are predominantly associated with GIT, oropharyngeal, vertebral spine, intra-abdominal region, pulmonary, and heart valves. Patients with P. micra bacteremia could have good prognosis following appropriate treatment.

Parvimonas micra: A potential causative pathogen to consider when diagnosing odontogenic brain abscesses

Background:

Brain abscess is a life-threatening entity which requires prompt and long-term antibiotic therapy, generally associated with surgical drainage, and eradicating the primary source of infection. Parvimonas micra (Pm) has only been reported once before as the lone infecting organism of an orally originated, solitary brain abscess. Diagnosing brain abscesses caused by this Gram-positive anaerobic coccus, constituent of the oral cavity flora, is challenging, and an optimal treatment regimen has not been well established. We report the diagnosis and successful treatment of a Pm caused odontogenic brain abscess.

Case Description:

A 62-year-old immunocompetent male with a right-parietal brain abscess presented with headache and seizures. He was started on empirical antibiotic therapy and subsequently underwent surgical drainage. The only source of infection found was severe periodontitis with infected mandibular cysts. Thus, tooth extraction and cyst curettage were performed 1 week after brain surgery. Cultures of brain abscess fluid were negative, but amplification of bacterial 16S ribosomal RNA (rRNA) with polymerase chain reaction demonstrated Pm. After 3 weeks of intravenous ceftriaxone and metronidazole, the patient was switched to oral metronidazole and moxifloxacin for 6 weeks.

Conclusions:

This case highlights the potential risk of untreated dental infections causing brain abscesses. Pm should be considered as a possible pathogen of odontogenic brain abscesses despite its presence usually not being detected by standard bacterial cultures. Therefore, 16S rRNA gene sequencing analysis is strongly recommended for bacterial identification before defining brain abscesses as cryptogenic.

Septic pulmonary embolism associated with periodontal disease: a case report and literature review

Background

Periodontal disease, including periodontitis, has been reported to be a rare cause of septic pulmonary embolism (SPE). It is however extremely difficult to isolate the causative pathogen of periodontal disease-associated SPE from blood cultures of these patients.

Case presentation

In this study, an 85-year-old Japanese man was admitted with fever and worsening malaise. He was later noted to have multiple bilateral subpleural pulmonary nodules on chest computed tomography scan. After admission, Parvimonas micra (P. micra) was isolated from his blood culture. This was followed by a meticulous search for the primary source of SPE, focusing on the head and neck areas. Consequently, apical periodontitis and infratemporal fossa abscess were identified as the primary sources of SPE. Although P. micra is one of the most frequently detected bacteria in the infected root canals of teeth with chronic apical periodontitis, it has rarely been proven as a causative pathogen of periodontal disease-associated SPE.

Conclusions

This case study demonstrated that periodontal disease is an important primary source of SPE and P. micra could be a causative pathogen of SPE.

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.

Gut Microbiome Analysis Identifies Potential Etiological Factors in Acute Gastroenteritis

The morbidity and mortality resulting from acute gastroenteritis and associated chronic sequelae represent a substantial burden on health care systems worldwide. Few studies have investigated changes in the gut microbiome following an episode of acute gastroenteritis. By using nondirected 16S rRNA gene amplicon sequencing, the fecal microbiota of 475 patients with acute gastroenteritis was examined. Patient age was correlated with the overall microbial composition, with a decrease in the abundance of Faecalibacterium being observed in older patients. We observed the emergence of a potential Escherichia-Shigella-dominated enterotype in a subset of patients, and this enterotype was predicted to be more proinflammatory than the other common enterotypes, with the latter being dominated by Bacteroides or Faecalibacterium The increased abundance of Escherichia-Shigella did not appear to be associated with infection with an agent of a similar sequence similarity. Stool color and consistency were associated with the diversity and composition of the microbiome, with deviations from the norm (not brown and solid) showing increases in the abundances of bacteria such as Escherichia-Shigella and Veillonella Analysis of enriched outliers within the data identified a range of genera previously associated with gastrointestinal diseases, including Treponema, Proteus, Capnocytophaga, Arcobacter, Campylobacter, Haemophilus, Aeromonas, and Pseudomonas Our data represent the first in-depth analysis of gut microbiota in acute gastroenteritis. Phenotypic changes in stool color and consistency were associated with specific changes in the microbiota. Enriched bacterial taxa were detected in cases where no causative agent was identified by using routine diagnostic tests, suggesting that in the future, microbiome analyses may be utilized to improve diagnostics.

Direct Gram staining and its various benefits in the diagnosis of bacterial infections

In the era of rapid development of molecular and other diagnostic methods, direct Gram staining (DGS) tends to remain in the background, although it can provide both microbiologists and clinicians numerous benefits. The aim of this review was to emphasize the importance of DGS for the diagnosis of many clinically important infections. A PubMed search was carried out using relevant keywords for articles published primarily since 2010. The DGS can provide early information for a timely diagnosis of infections, can reveal the causative agents of the infections even under suboptimal conditions of specimen collection, transport or identification methods, can detect the presence of rare/unusual pathogens, moreover, the method shows the specimen quality, by distinguishing between contamination and true infection, it can direct or change initial antibiotic treatment before the availability of culture results, can indicate the need of other methods for pathogen identification and, in some cases, can show the need for emergency attention such as urgent antibiotic therapy and surgical measures. Briefly, the DGS remains an easy, rapid, inexpensive and important method, which use should be encouraged in conditions of a standardized and controlled performance to avoid technical or interpretation errors.