[Multiresistant nosocomial bacterial strains and their "in vitro" susceptibility to chloramphenicol and colistin].
OBJECTIVE
A multicenter study was conducted to obtain "in vitro" chloramphenicol and colistin susceptibility data on multiresistant hospital bacterial pathogens in Slovak Republic.


METHODS
During the period of April-June 2001, 628 clinical bacterial multiresistant isolates from patients with serious infections were selected in 10 hospitals and tested to a large scale of antibiotics by means of a microdilution method. The strains expressed either a significant resistance phenotype (ESBL, MRSA, CoNMRS, MLSB/c, efflux in Ps. aeruginosa), or were resistant to one or more preparations in at least half of reliable unrelated antibiotic groups (beta-lactams, aminoglycosides, quinolons, macrolides).


RESULTS
Both chloramphenicol and colistin retained significant "in vitro" activity against many multiresistant hospital bacterial pathogens. The highest activity of chloramphenicol was documented for isolates of Stenotrophomonas maltophilia (76,5 % susceptible, MIC50 = 4 mg/L, MIC90 = 16 mg/L) and of Staphylococcus aureus (76,2 % susceptible, MIC50 = 8 mg/L, MIC90 = 16 mg/L). In tested Pseudomonas aeruginosa (82,5 % susceptible, MIC50 = 2 mg/L, MIC90 = 16 mg/L) and Stenotrophomonas maltophilia (88,2 % susceptible, MIC50 = 1 mg/L, MIC90 = 8 mg/L) isolates colistin represented the most "in vitro" effective antibiotic. Colistin was the only "in vitro" effective antimicrobial in four of 120 multiresistant Pseudomonas aeruginosa isolates tested in our study.


CONCLUSIONS
The study confirmed a good "in vitro" susceptibility of many multiresistant hospital bacterial pathogens to chloramphenicol and colistin in Slovak Republic. The clinical application of chloramphenicol and colistin might be reconsidered in infections caused by extremely resistant bacteria with prooved susceptibility to these antibiotics. It is important to consider, that the infection danger has to exceed the risk of antibiotic toxicity.
Niks
Milan
M
Pulic health authority of the Slovak Republic, Bratislava, Slovak Republic, niks@szusr.sk
Hanzen
Juraj
J
Ohlasová
Daniela
D
Rovná
Daniela
D
Purgelová
Anna
A
Szövényiová
Zuzana
Z
Vaculíková
Alena
A
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002701:Chloramphenicol; D003091:Colistin; D003428:Cross Infection; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D002701:Chloramphenicol; D003091:Colistin