The aetiologic agents and resistance rates in community-acquired complicated intra-abdominal infections: Where are we locally?

BACKGROUND

Community-acquired complicated intra-abdominal infections (CA-cIAIs) are a significant global health concern, associated with considerable morbidity and mortality. In regions lacking local epidemiological data, obtaining intraoperative cultures is recommended to guide empirical antibiotic selection. This study aimed to describe the local microbiological profile and resistance patterns in CA-cIAIs.

METHODS

We retrospectively reviewed adult patients operated for CA-cIAIs at Ankara University Hospital between January 2018 and December 2023. Inclusion criteria included intraoperative or percutaneous drainage sampling and absence of recent hospitalization or abdominal procedures within three months.

RESULTS

Among 124 surgical patients, cultures were collected from 80 (64.5 %), with 44 (70 %) yielding microbiological growth. A total of 69 pathogens were identified. The most frequent infection sources were cholecystitis (36 %), appendicitis (27 %), and colon perforation (20 %). Escherichia coli (46.4 %), Klebsiella pneumoniae (10.1 %), and Enterococcus faecalis (8.7 %) were the predominant organisms. Extended-spectrum beta-lactamase (ESBL) production was observed in 30.4 % of Gram-negative strains, with notable resistance to third-generation cephalosporins (40 %) and fluoroquinolones (33.3 %). Empirical antibiotics included piperacillin-tazobactam (77.2 %) and teicoplanin (47.7 %). However, their predictive values were low (PPV: 32.4 % and 38.1 %, respectively), with moderate concordance rates.

CONCLUSIONS

E. coli remains the leading pathogen in CA-cIAIs, but rising resistance rates to key antibiotics pose challenges to empirical treatment. Although piperacillin-tazobactam and teicoplanin were the most commonly used empirical agents, their low PPV underscore the need for improved strategies to optimize empirical therapy. Our findings emphasize the importance of obtaining intraoperative cultures to enable timely de-escalation and appropriate antimicrobial stewardship.