#21: Risk Factors and Clinical Characteristics of Stenotrophomonas Maltophilia Infections in Neonates & Children from Day 1 to 21-Year Old Between the Years 2008 to 2020

Abstract Background Stenotrophomonas maltophilia is a ubiquitous organism associated with opportunistic infections. In the immunocompromised host, increasing prevalence and severity of illness is observed, particularly opportunistic bloodstream infections and pneumonia syndromes. S. maltophilia is intrinsically resistant to most currently available broad-spectrum antibiotics, including carbapenems and beta-lactams. This intrinsic resistance is due to the presence of chromosomally expressed beta-lactamases, L1 (a metallo-carbapenemase), and L2 (an extended-spectrum beta-lactamases), which together can hydrolyze nearly all betalactam antibiotics including carbapenems. In vitro activity is observed with tetracyclines and fluoroquinolones, but resistance can be rapidly induced mainly due to efflux pumps. Trimethoprim/sulfamethoxazole (TMP-SMX) generally is considered the treatment of choice for S. maltophilia infection, although consideration of S. maltophilia in treatment guidelines is sparse. Additionally, a recent study suggests that S. maltophilia susceptibility to TMP-SMX may be decreasing globally, due in part to acquired antibiotic resistance. Though historically identified as a cause of nosocomial infections, communityonset infections increasingly are being reported. From 1996 to 2016, S. maltophilia was commonly isolated from patients hospitalized with pneumonia and bloodstream infection (BSI), and the incidence of S. maltophilia infection is increasing Methods A retrospective analysis of characteristics and outcomes in patients with S. maltophilia–positive cultures were conducted using the Healthbridge EHR. Study Population This retrospective matched case control study was carried out in neonates with S. maltophilia infections at UHB DOWNSTATE MEDICAL CENTER NICU and Pediatric Department between 2008 and 2020. To identify the case patients, we reviewed the admission and medical records of patients and records from the Microbiology Department in the study period. Control patients were selected from the patients who admitted for at least 72 hours and had pneumonia and/or nosocomial sepsis caused by pathogens other than S. maltophilia. To determine the risk factors for S. maltophilia infections among 35 case patients were compared with 35 control patients. Medical charts of all infants with positive cultures for S. maltophilia and control cases were reviewed for birth weight; gestational age; delivery type; postnatal age at hospitalization; prolonged rupture of membranes; invasive procedures (mechanical ventilation, intubation, urinary catheter, umbilical catheter); duration of mechanical ventilation (day); exposure to antimicrobial agents (aminoglycosides, carbapenems, cephalosporins, penicillins); administration of total parenteral nutrition (TPN); duration of TPN; histamine 2 (H2) blockers; exposure to steroids; cholestasis; elevated liver enzymes; death; sepsis-related death; and duration of hospitalization. All the risk factors for infection were calculated before the onset of infection in both groups. Results in progress Conclusions: