Pathogens distribution and antimicrobial resistance pattern of blood stream infections in Southern Italian hospital, 2016-2021 surveillance

Bloodstream infections (BSIs) monitoring and antibiotic susceptibility assumes a priority relevance to guide antibiotic treatment strategies and prevention programs. The study aims to identify the most common causative agents of BSIs, seasonal distribution and variation of antimicrobial susceptibility rates during a 6-year period in a in a Level II EAD Southern Italian Hospital. The study was conducted from 2016 to 2021 at Hospital of National Relevance (AORN) Sant'Anna and San Sebastiano, Caserta, Campania Region in Italy. BSIs Gram positive causative pathogens were S. aureus and Enterococci; Gram negative pathogens were E. coli, K. pneumoniae, P. aeruginosa and A. baumannii. Seasonal distribution showed the main incidence in April-June for Gram positive BSIs pathogens and in July -Septem-ber months for Gram negative. Antimicrobial susceptibility fluctuations rates from 2016-2018 to 2019-2021 highlighted a significant decrease in S. aureus oxacillin resistance rates. Enterococci incremented resistance was reported for gentamicin. Gram negative pathogens antimicrobial susceptibility revealed decreased carbapenem-resistance rates for K. pneumoniae (-21.5%) and P. aeruginosa (-19.7%). A. baumannii colistin resistance had a significant increase in 2019-2021. K. pneumoniae and E. coli isolates showed decreased trend of extended-spectrum beta-lactamase-producing (ESBL) and carbapenem-resistant (CRE) resistance profiles. Our finding reflects the success of our Istitution regarding antimicrobial stewardship program and highlights the need to know the trend of antimicrobial resistance characterization focus on local pathogens' profile. In this way, in conjunction with infection control strategies, il could be possible to constantly reduce the spread of Multi Drug Resistant organisms.