Trends and Impact in Antimicrobial Resistance Among and Species in 2007-2012 Compared to 2013-2017.

The aim of this study was to analyze the susceptibility of and spp. strains, isolated from patients hospitalized in the clinical hospital in Poland to penicillin, amoxicillin with clavulanic acid, imipenem, clindamycin, and metronidazole. We analyzed susceptibility of 476 isolates to routinely use for the treatment of anaerobic bacterial infections antibiotics. test method was used to determining the minimal inhibitory concentration values. To show the trend of drug resistance, we compared data from two periods within the years 2003-2017. Research results indicate that the problem of resistance is mainly related to strains belonging to non-fragilis . In the analyzed periods, there was an increase in the percentage of clindamycin-resistant isolates (35.21% vs. 53.33%), amoxicillin/clavulanic acid (2.83% vs. 8.15%), and imipenem (1.41% vs. 3.7%). In isolates belonging to , we observed a constant high (∼50%) percentage of clindamycin-resistant strains. The overwhelming majority of strains were resistant to penicillin (>95%) and about 20% of the isolates were not susceptible to clindamycin. Clindamycin, due to the high and increasing percentage of resistant strains, may not be a good choice in the empirical therapy of infections caused by and . Our study highlighted the importance of a routine or at least periodic monitoring of antimicrobial susceptibility of anaerobic Gram-negative bacilli, providing important information for appropriate therapy. The study shows that infection caused (or suspected of being caused) by and spp. can be empirically treated with metronidazole or imipenem.