35 Nosocomial spondylodiscitis by P.aeruginosa: an uncommon and severe complication of abdominal surgery

Introduction Healthcare-associated infections (HCI) represent a significant public health issue as they increase the costs, hospital stay and morbi-mortality of patients. Many of the microorganisms responsible for these infections are known for their multidrug resistance, which presents a significant challenge when implementing appropriate antibiotic treatment. We present the case of a patient with a history of intensive care unit (ICU) admission due to diverticular bleeding, requiring surgical intervention. Afterwards, he developed spondylodiscitis as a consequence of bacteremia caused by Pseudomonas aeruginosa. Case Report A 68-year-old male patient was admitted to the ICU due to anaemia and instability from diverticular bleeding. Surgery was eventually indicated, revealing diverticulosis with no signs of infection, and a left hemicolectomy with colorectal anastomosis was performed. Preoperative blood cultures revealed the presence of Citrobacter koseri and Pseudomonas aeruginosa, and empirical antibiotic treatment with Piperacillin-Tazobactam (PT) was initiated. On the third postoperative day, the patient had a fever of 39°C, purulent drainage from the surgical wound, and phlebitis in the peripheral venous line, which was removed. Wound and blood cultures were taken, and an urgent computed tomography (CT) scan described anastomosis dehiscence and hemoperitoneum, inducing a second surgery. No dehiscence or active bleeding was observed, so the peritoneal cavity was irrigated, the enterotomy suture was reinforced and a sample was taken for culture. The cultures from the surgical wound showed Enterococcus faecium, E. coli, and B. fragilis. The abdominal fluid cultures showed E. coli resistant to PT and E. faecium. The blood cultures, after two weeks of antibiotic therapy with PT, showed P. aeruginosa sensitive to gentamicin, tobramycin, and amikacin, but resistant to PT. Based on these results, we consulted the hospital infectious diseases team. The antibiotic therapy was adjusted to Meropenem and Teicoplanin. Due to persistent fever, a new CT scan was performed, revealing intra-abdominal collections, so percutaneous drainage was placed. The patient subsequently showed good progress and was discharged after 21 days of treatment with Meropenem and Teicoplanin. Weeks later, the patient began experiencing moderate to severe lower back pain and functional limitation, without fever or other significant symptoms. An MRI described L3-L4 spondylodiscitis with an associated epidural collection. The diagnosis of nosocomial spondylodiscitis due to Pseudomonas aeruginosa was confirmed through radioguided vertebral disc biopsy. The patient was admitted and treated with targeted antibiotics completing a total of 7 weeks of treatment, with good clinical progress. Discussion Nosocomial infections represent a significant public health issue worldwide, with over 30% of cases being preventable. Bacteremia can lead to distant effects, such as osteomyelitis or of the vertebral bodies and discs, known as spondylodiscitis. This condition is very rare, with a mortality rate of up to 17%. Its diagnosis is often delayed due to the presence of nonspecific symptoms and is confirmed through imaging tests, with MRI being the gold standard. The treatment of choice will be antibiotic therapy for 3–12 weeks, reserving surgery for cases of spinal cord or nerve root compression with abscesses, bony spinal instability.