Prevalence of Enteric Pathogens and Antibiotic Resistance: Results of a Six-Year Active Surveillance Study on Patients Admitted to a Teaching Hospital.

Background: Acute Infectious Diarrhea (AID) and the short- and long-term complications associated with it are major causes of hospitalization worldwide. In Italy, due to a lack of robust surveillance programs, only limited data has been collected on their prevalence and circulation. This study aims to evaluate the resistance pattern of enteric pathogens and their epidemiological trends over a six-year period.

Methods: This cross-sectional retrospective study was conducted from January 2018 to December 2023. Stool samples were analyzed during routine diagnosis with culture methods, syndromic molecular tests, and enzyme immunoassay.

Results: Bacteria were the most isolated enteric pathogens (62.2%), followed by fungi (29.0%), viruses (8.2%), and parasites (0.6%). Most bacteria were isolated from outpatients (29.5%) and from patients in the Oncology ward (26.2%). The most prevalent target was EPEC (11.1%), followed by toxin A/B-producing strains (8.3%), (2.5%), and , (1%.). Norovirus and spp. were the most prevalent in pediatric patients (6.5% and 39.6%, respectively). In the last years, enteric pathogens have been a frequent cause of infections characterized by a problematic resistance to common antimicrobials. In our study, showed resistance to amikacin, gentamicin, ampicillin, levofloxacin, and ciprofloxacin. was susceptible to all tested drugs.

Conclusion: Timely notification of gastroenteric infections is crucial in identifying potential outbreak sources and ensuring strict adherence to food safety and hygiene practices, so as to protect the most vulnerable populations. The present study offers insights into the epidemiological characteristics and the antibiotic susceptibility of the main enteric AID pathogens in order to implement infection control measures in health care settings.