Aggregatibacter actinomycetemcomitans infection in a 15-year-old boy with pulmonary empyema: a case report and review of literature

Abstract

Background Aggregatibacter actinomycetemcomitans (Aa), previously known as Actinobacillus actinomycetemcomitans, is a slow-growing Gram-negative coccobacillus, member of the HACEK group of bacteria colonizing oral flora. Besides causing infectious diseases in the oral cavity such as dental caries and periodontitis, it is responsible for severe extra-oral infections secondary to hematogenous spread or aspiration, such as endocarditis, soft tissue abscesses and osteomyelitis. The diagnosis depends on prolonged bacterial culture of biological material obtained through biopsy. Aa is susceptible to most antibiotics but complete eradication often requires a long term treatment. Case presentation We report the case of a 15-year-old previously healthy boy diagnosed with both pulmonary empyema and subphrenic chest wall abscess caused by Aa. He was admitted to our Pediatric Emergency department for evaluation of a right mass associated with marked asthenia and dry cough. After radiological findings etiological diagnosis was made by culture of fluid drainage of pleural empyema. He started empirical antibiotic therapy with intravenous piperacillin/tazobactam, whose sensibility was confirmed by the antibiogram, then, for occurrance of hepatopathy it was switched to ciprofloxacin: the patient almost completely recovered after 6-month therapy. Conclusions Extra-oral infections caused by Aa are extremely rare, especially in children, and not well described yet. To our knowledge, there is only another similar case described in literature. However, the case described in our manuscript represents the only one presenting with pulmonary empyema without involvement of lung parenchyma in children. We also conducted a brief review of published cases of Aa infection in the pediatric population. This case report reminds us the importance of an accurate inspection of the oral cavity during the examination of pediatric patients.

Whole Genome Sequencing and Phenotypic Analysis of Antibiotic Resistance in Filifactor alocis Isolates

“…Other weapons in F. alocis’ arsenal include (1) the production of exotoxins, such as FtxA, which belongs to the RTX family and might help damage the surrounding cells by forming pores in the membranes of epithelial cells [ 13 ], (2) the ability to overcome oxidative stress thanks to enzymes such as superoxide reductase, which helps F. alocis to overcome the neutrophil response [ 14 ], and (3) the capability of mechanically adapting to the environment by forming pili-like projections [ 15 , 16 ]. To make things worse, and similar to other periodontopathogens such as Porphyromonas gingivalis , Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans , F. alocis has also been detected in non-oral environments such as lung and brain abscesses [ 17 , 18 , 19 , 20 , 21 ].…”