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

The Metabolic Potential of the Human Lung Microbiome

The human lung microbiome remains largely underexplored, despite its potential implications in the pharmacokinetics of inhaled drugs and its involvement in lung diseases. Interactions within these bacterial communities and with the host are complex processes which often involve microbial small molecules. In this study, we employed a computational approach to describe the metabolic potential of the human lung microbiome. By utilizing antiSMASH and BiG-SCAPE software, we identified 1831 biosynthetic gene clusters for the production of specialized metabolites in a carefully compiled genome database of lung-associated bacteria and fungi. It was shown that RiPPs represent the largest class of natural products within the bacteriome, while NRPs constitute the largest class of natural products in the lung mycobiome. All predicted BGCs were further categorized into 767 gene cluster families, and a subsequent network analysis highlighted that these families are widely distributed and contain many uncharacterized members. Moreover, in-depth annotation allowed the assignment of certain gene clusters to putative lung-specific functions within the microbiome, such as osmoadaptation or surfactant synthesis. This study establishes the lung microbiome as a prolific source for secondary metabolites and lays the groundwork for detailed investigation of this unique environment.

Labial Necrotizing Fasciitis Caused by Pelvic Eggerthia catenaformis Infection

A patient with comorbid diabetes mellitus, obesity, and hypertension acutely presented to the ED due to labial cellulitis with rapidly progressing symptoms of systemic inflammation. Clinical examination revealed fever and groin pain that was tender to palpation. Initial contrast-enhanced CT scans showed labial cellulitis extending to the inguinal canal, with later CT imaging findings of subcutaneous air indicative of necrotizing fasciitis (NF). Antimicrobial therapy was initiated empirically and later tailored to culture antibiogram. The patient underwent acute surgical abscess drainage and tissue debridement but was transferred to the surgical intensive care unit (SICU) due to postoperative blood loss and hypotension. Two additional surgical procedures were needed before sufficient drainage was achieved, and Eggerthia catenaformis (E. catenaformis) was isolated from all samples. Due to the extent of the infection, the patient was admitted for a total of 16 days, with five days spent in the SICU. They recovered completely due to adequate surgery and antimicrobial therapy for a total of 24 days. Here, we present the third reported case of NF due to E. catenaformiswhile emphasizing timely treatment with empiric antibiotics and surgical intervention.

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.

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.

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.

Severe deep neck space infection caused by Eggerthia catenaformis

A 64-year-old woman was acutely referred to the Department of Otorhinolaryngology, Head and Neck Surgery, Aalborg University Hospital due to rapidly progressing neck swelling, fever and dysphagia. Clinical examination revealed submental swelling, trismus and laryngeal inflammation. A contrast-enhanced CT scan showed infection in the deep neck spaces with multiple abscesses. The patient underwent acute surgery and antimicrobial therapy was initiated and she was transferred to an intensive care unit. Three additional surgical procedures were needed before sufficient drainage was achieved. There was growth of different oral commensals from four separate pus aspirates, while Eggerthia catenaformis was cultured in all samples. Due to the extent of the infection, the patient stayed in the intensive care unit for 16 days, but recovered completely due to adequate surgery and antimicrobial therapy for 4 weeks. Here we present the third reported case of a severe deep neck space infection with multiple abscesses due to E. catenaformis.

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.

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.