The first case of deep neck abscess due to Filifactor alocis co-infected with Eggerthia catenaformis, Parvimonas micra, and Streptococcusconstellatus.

Filifactor alocis, an anaerobic Gram-positive rod, has garnered interest from its association with periodontal disease. Extraoral infections by F. alocis are rare; only seven cases have been reported. We report the first case in which we identified F. alocis as one of the causative organisms of a deep neck abscess. A 71-year-old male on hemodialysis came to our hospital with a fever and left buccal pain. The patient's left neck was swollen, and contrast-enhanced computed tomography showed an abscess with gas extending from the left cheek to the deep neck. We diagnosed the patient with a deep neck abscess and performed an urgent neck drainage. We isolated F. alocis, Eggerthia catenaformis, Parvimonas micra, and Streptococcus constellatus in the abscess and identified them using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Blood cultures were negative. We initiated treatment with piperacillin-tazobactam and vancomycin. The patient improved but developed a hemorrhagic duodenal ulcer on the third day of admission. We attempted endoscopic hemostasis, but the patient's bleeding continued. Ultimately, he died of the duodenal ulcer hemorrhage on the sixth day of admission. This is the first case of F. alocis detected in a deep neck abscess.

Eggerthia catenaformis-related peritonitis in a patient with peritoneal dialysis.

Eggerthia catenaformis is a Gram-positive bacilli and an anaerobic and non-spore-forming bacterium, which rarely causes infections in humans. We present a case of peritonitis caused by E. catenaformis in a peritoneal dialysis patient. The isolate was identified as E. catenaformis with the MALDI-TOF MS method as in other cases in the literature. To the best of our knowledge, this is the first case of peritonitis caused by E. catenaformis in a human host.

The first case of septic arthritis of the knee caused by Eggerthia catenaformis.

Eggerthia catenaformis has been reported as a human pathogen. We present the first case of the primary knee infection caused by Eggerthia catenaformis in a 23-year-old male patient with a knee infection, after primary anterior cruciate ligament reconstruction. Eggerthia catenaformis was confirmed by MALDI-TOF mass spectrometry from synovial fluid. The dental focus was excluded. The isolated bacterial strain showed sensitivity to all of the tested antimicrobials. However, for successful management of knee infection, besides culture-directed antibiotics therapy, arthroscopic debridement and lavage were necessary.

Bactericidal activity of a substituted thiazole against multidrug-resistant Eggerthia catenaformis isolated from patients with dental abscess.

Human infections caused by the anaerobic bacterium Eggerthia catenaformis are rare. However, a growing number of case reports have presented the bacterium as the causative agent in many serious complications. This study provides data on the isolation and antibiotic susceptibility profiles of E. catenaformis from dental abscess. Identification of isolates was performed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). We also investigated the antibacterial activity of 5-acetyl-4-methyl-2-(3-pyridyl) thiazole (AMPT) on E. catenaformis isolates. Minimum inhibitory concentrations (MICs) were determined by an agar dilution method and bactericidal activity was evaluated by a time-kill assay. Moreover, the mechanism of action of AMPT was also explored by cell membrane disruption assay and scanning electron microscopy (SEM). MALDI-TOF MS results revealed unambiguous identification of all isolates with score values between 2.120 and 2.501. Isolates NY4 and NY9 (20% of isolates) were found resistant to multiple antibiotics judged by MIC values. As multidrug-resistant strains of E. catenaformis were not reported to date, we then confirmed the identity of NY4 and NY9 based on 16S rRNA gene sequence. Favorably, all isolates were susceptible to AMPT with an MIC range of 0.25-1 mg/L. Time-kill kinetics of AMPT indicated that it exhibited potent bactericidal activity against the multidrug-resistant isolates NY4 and NY9. Furthermore, this study also hypothesizes that AMPT exerts its antibacterial effect through damaging the cell membrane and thereby induce the release of intracellular components. AMPT could therefore be considered as a therapeutic option for infections caused by multidrug-resistant bacteria.

First report of bacteremia caused by Eggerthia catenaformis in a patient with gastric malignancy in China.

Bacteremia caused by Eggerthia catenaformis is a rarely reported pathogen in cancer patients. Herein, we report a case of bacteremia caused by E.catenaformis in a patient with gastric cancer in China. The patient was a 55-year-old man, diagnosed with gastric cancer more than one month ago, with intermittent fever at a maximum of 39.5 °C for more than half a month. He received symptomatic and supportive treatment after admission to our hospital; a rare anaerobic microorganism, E. catenaformis was isolated from an anaerobic blood culture sample taken from the patient. The antimicrobial susceptibility testing was performed after the isolates were successfully identified by MALDI-TOF MS and 16S rRNA sequencing. The patient was then successfully treated for the bacteremia with metronidazole. To the best of our knowledge, this is the first report of E. catenaformis bacteremia in a patient with cancer.

Eggerthia catenaformis bacteremia in a patient with an odontogenic abscess.

Eggerthia catenaformis is a Gram-positive anaerobic rod, which has been rarely reported in human diseases. We report the second case of bacteremia due to this microorganism in an elderly patient. A 73-year-old man, without underlying diseases presented with fever, odynophagia and swelling of the cervical lymph node for several days. Culture of drained cervical fluid resulted in the isolation of Raoultella ornithinolytica and Streptococcus anginosus. Anaerobic blood cultures yielded a rare anaerobic microorganism, identified as Eggerthia catenaformis. No resistance to tested antimicrobials was documented. Treatment with drainage and several antibiotic regimens was established, and the general condition of the patient improved, at two months of follow-up.

First case of pleural empyema and pulmonary abscess caused by Eggerthia catenaformis.

Few data are available on the anaerobic bacterium Eggerthia catenaformis. Here we report the first clinical case of a patient with sepsis caused by pulmonary infection with E. catenaformis, and present the minimal inhibitory concentrations of different antimicrobial agents.

First clinical description of Eggerthia catenaformis bacteremia in a patient with dental abscess.

We present a case of Eggerthia catenaformis bacteremia originating from a dental abscess and imitating necrotizing fasciitis in a previously healthy adult. The isolates were easily identified by MALDI-TOF MS. The clinical course, surgical and antibiotic treatment as well as the successful outcome are reported.

Descending necrotizing mediastinitis caused by retro-pharyngeal Eggerthia catenaformis infection.

Introduction: Eggerthia catenaformis, a non-spore-forming anaerobic Gram-positive bacillus component of the human fecal microbiota has rarely been reported in human diseases. In almost every case described in current literature to date, dental diseases (abscesses, periodontitis, or caries), are the most common source of the infection which extends to the brain, cervical spaces, pulmonary parenchyma, the pleural cavity, the abdominal wall, and the abdominal cavity. Case report: An 82-year-old male Caucasian patient was admitted to our Emergency Department (ED) with a painless, right submandibular mass, dyspnea, and inspiratory stridor. A CT scan of the head, neck, and chest with intravenous contrast material revealed a retrotonsillar fluid collection. Air bubbles and minimal fluid were present from the right sub-mandibular area to the lower mediastinum between the spine, the descending thoracic aorta, and the trachea. The patient underwent surgical treatment and a broad-spectrum antibiotic. The retropharyngeal fluid collection culture showed the presence of Eggerthia catenaformis. After a first period in the Intensive Care Unit, he was admitted to a Step-Down Unit (SDU) where he underwent respiratory weaning, motor rehabilitation, and gradual oral feeding resumption. At discharge, the patient maintained the tracheal cannula as he still had impaired swallowing of solid foods. Conclusions: Here we report the first case of descending necrotizing mediastinitis in a patient with a retropharyngeal abscess, in the absence of dental diseases.

First case of deep neck and descending mediastinal abscess caused by dentoalveolar Eggerthia catenaformis infection.

Descending mediastinal abscesses arising from oral (dental or peritonsillar abscess) or deep neck infections (DNIs) often become fatal without surgical drainage. Odontogenic origin was the most common cause of DNIs. We report the first clinical case of a patient with descending mediastinal abscess caused by DNI from Eggerthia catenaformis a Gram-positive anaerobic rod that can be rarely a human pathogen. The patient underwent the extraction of carious molars, cervical and thoracic surgical drainage, and targeted antibiotic therapy with resolution of the infection.

Eggerthia catenaformis infection originating from a dental abscess causes severe intestinal complications and osteomyelitis of the jaw.

Introduction: Odontogenic foci may result to generalized infections spreading the bacteria through contiguous anatomic cavities or hematogenous spread. The most reported secondary infections caused by oral pathogens are intracranial abscesses. Although, few reports in the literature describe the bacterial spread to extracranial locations. Case description: We describe the case of a 52-year-old male Caucasian patient who was admitted to our hospital suffering from severe sepsis caused by a submandibular abscess. Eggerthia catenaformis was detected in blood and abscess material (confirmed by MALDI-TOF mass spectrometry). The patient subsequently developed a perihepatic abscess and colon perforation, and was stabilized after several surgical interventions. He remained hospitalized for 66 days receiving intravenous antibiotics. Five months later, jaw osteonecrosis with Actinomyces contamination was detected in the left mandible, which also had to be treated surgically. Three years after the last surgery, no signs of recurrence have been detected. Discussion: Oral and maxillofacial surgeons should understand the characteristics of systemic infections, in which the potentially causal intraoral odontogenic foci often lack acute symptoms. If other origins of infection are not detected, elimination of the potentially causal odontogenic foci should be performed. However, the decision making criteria to eliminate suspected causal teeth is needed to be elucidated through more studies.