Epidemiological and clinical investigation of Gram-negative anaerobic infections in Greece

Abstract number: 1733_864

Katsandri A., Avlamis A., Legakis N.J., Petrikkos G.L., Pantazatou A., Papaparaskevas for The Hellenic Study Group for Gram-Negative Anaerobic Bacteria* J.

Objective: Epidemiological and clinical investigation of Gram(-) anaerobic infections.

Materials and Methods: A prospective multicentre study of 206 Gram(-) anaerobic infections was conducted during the period 2003–2006. Data collected included gender, age, ward type, duration of hospitalisation, underlying disease, clinical manifestation, outcome, prior antimicrobial therapy, infection treatment, and microbiological data (clinical specimen, species identification, other pathogens from the same specimen). Analysis was performed with the STATA 6.0 programme.

Results:Bacteroides spp. isolates were more frequent in intra-abdominal infections (p < 0.001). Infections due to B. fragilis compared to other species of the B. fragilis group were more frequent in surgical ward patients (p = 0.008), and those who received treatment with second generation cephalosporins (p = 0.017). In bacteraemic cases, Bacteroides non-fragilis spp. were more frequent than B. fragilis group spp. (p = 0.02). B. fragilis group spp. were isolated more frequently than Bacteroides non-fragilis spp. in polymicrobial infections (p = 0.05), and younger patients (p = 0.049, for median ages of 47.4 and 61.3 years). Prevotella spp. strains were more frequent in pulmonary infections compared to bacteraemias, soft tissue, or intrabdominal infections (p < 0.001), from outpatients than inpatients (p < 0.05), and from patients with shorter hospitalisation duration (p = 0.033). Fusobacterium spp. were isolated more frequently from patients with lung abscess (p = 0.038), and from those that did not receive any form of antimicrobial therapy (p = 0.024). Mortality was higher among bacteraemic patients (p < 0.001), those that were hospitalised in internal medicine dpts. or ICU (p = 0.001), or those that were treated with aminoglycosides (p = 0.008). Among polymicrobial infections an association was detected between Staphylococcus and Prevotella spp. (p = 0.006), and between Enterobacteriaeae and Bacteroides spp. (p = 0.007).

Conclusions: Epidemiological and clinical differences were detected among cases of infections due to different Gram(-) anaerobic species, differences that provide useful information for optimisation of the respective empirical treatment guidelines.

Acknowledgements: The study was funded by European Social Fund and National Resources (grant EPEAEK II–Pythagoras II).

*Drs M. Foustoukou, M. Kanellopoulou, C. Koutsia-Karouzou, H. Malamou-Ladas, A. Pangalis, E. Papafrangas, M. Toutouza, E. Trika-Grafakos, and A. Vogiatzi.