ABSTRACT

Pseudocitrobacter faecalis is an uncommon member of the order Enterobacterales, initially described from fecal specimens, and has subsequently been reported from clinically significant infections, including bloodstream infections, sepsis and urinary tract infections. Multidrug-resistant and carbapenem-resistant isolates have also been described. However, its clinical significance when repeatedly recovered from intra-abdominal drainage specimens remains uncertain.
A 37-year-old man with no known comorbidities was admitted under the Department of Surgical Gastroenterology with acute moderately severe pancreatitis complicated by colonic perforation. He underwent emergency exploratory laparotomy with diversion loop ileostomy and placement of percutaneous catheter drainage (PCD), followed by surgical drainage. Empirical antimicrobial therapy with meropenem, tigecycline and teicoplanin was initiated. P. faecalis was repeatedly isolated as pure growth from PCD/drainage specimens received over a period of approximately five days. The organism was identified by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing by VITEK 2 demonstrated resistance to amikacin, ceftriaxone, ceftazidime, piperacillin-tazobactam, imipenem, meropenem and minocycline, while colistin was reported as intermediate. The isolate was resistant to ceftazidime-avibactam, whereas qualitative ceftazidime-avibactam–aztreonam synergy testing demonstrated a positive synergistic effect. Despite the susceptibility profile, the empirical antimicrobial regimen was continued, and the patient’s clinical condition subsequently improved.
Repeated recovery of multidrug-resistant faecalis from intra-abdominal PCD/drainage specimens highlights the need to recognize this uncommon organism and carefully assess its clinical significance in patients with gastrointestinal disease. Its multidrug-resistant phenotype and limited in-vitro therapeutic options also emphasize the importance of accurate identification and antimicrobial susceptibility testing of uncommon Enterobacterales isolates.