Title : Staphylococcus pettenkoferi: A first case report on abscess formation
Abstract:
Coagulase-negative staphylococci (CoNS) remain some of the commonest causes of nosocomial bacteremia, and as genomic identification become more precise, new infectious organisms are reported as the causative agent of bacteremia. Here we report the first published case of Staphylococcus pettenkoferi in Louisiana, the first known infection to form an abscess, and a patient’s clinical course for an emerging opportunistic infection in the United States. Poorly understood, S. pettenkoferi is a commensal bacterium of rising clinical importance.
A 44-year-old woman with class III obesity presented to hospital for evaluation of fever and abdominal pain for three days associated with dyspnea, palpitations, nausea, and frequent emesis. Upon arrival, she was tachycardiac with abominable distention, erythema, abdominal mass, and tenderness to palpation in the umbilical region. The patient was started on vancomycin and piperacillin/tazobactam and admitted for further management. Abominable/pelvic CT demonstrated a large ventral defect with extensive soft tissue inflammation without fluid collections. Plastic surgery was consulted, who deemed surgery to perform a panniculectomy too risky. Blood cultures resulted in Gram-positive cocci, and piperacillin/tazobactam was discontinued. Infectious disease specialists recommended cefepime which was started.
The following day, drainage was noted from the patient’s prior hernia scars, and a CT was repeated which demonstrated a fistula connecting an abscess measuring 10.2 x 4.9 x 13.3 cm in the anterior abdominal wall to colon. Interventional radiology and general surgery were consulted for possible intervention of the abscess. Due to body habitus both procedures were contraindicated. CeDAR score showed a 99% chance of a major complication if surgery were to be undertaken. Repeat blood cultures taken on day three of hospitalization resulted as negative.
The patient remained in hospital on antibiotics for 11 days then transferred to a long-term care facility (LTAC) in stable condition. Piperacillin/tazobactam was changed to vancomycin for MRSA coverage and then to doxycycline and amoxicillin/clavulanic acid. Two-month follow up demonstrated lingering though smaller abscess presence and continued fistula drainage while the patient remained on oral antibiotics.
Multiple opportunistic infections can cause serious harm once given the chance to infect, yet the ability of S. pettenkoferi remains poorly understood. Here we report of the first known instance of S. pettenkoferi in the state of Louisiana and the first known to cause abscess. Current published literature conflicts the status of S. pettenkoferi as possible of causing true bacteremia versus it being a benign contaminant. As microbial analysis and identification becomes more precise, S. pettenkoferi may reveal to be the underlying agent in increasing numbers of CoNS infections.
