Antibiotipos de cepas bacterianas aisladas de pacientes de las Unidades de Cuidados Intensivos / Antibiotypes of bacterial strains isolated from patients at the intensive care units

The indiscriminate use of antibiotics in intensive care units has permitted the selection of multiple resistant bacterial strains in the hospital setting. Antibiograms present the sensitivity or resistance of these strains to drugs in current use. In this study, 100 bacterial strains were isolated from patients on medical and surgical ICU wards. The strains were identified by API-20E and sensitivity testing was performed by the E-test procedure. MIC were further analyzed with the WHONET software wich permits the identification of antibiotypes. Acinetobacter anitratus, Pseudomona aeruginosa and Enterobacter cloacae were the most resistant strains. Nine antibiotypes were determinated for A. Anitratus. Predominant strain presented antibiotypes with multiple resistance to ten antibiotics. P. aeruginosa presented 10 antibiotypes, the predominant one being CTX, CRO, CTX. Antibiotype determination allows phenotypic identification or resistance patterns in particular species as well as facilitates follow up and recognition of its epidemiological distribution

[Antibiotypes of bacterial strains isolated from patients at the intensive care units]. / Antibiotipos de cepas bacterianas aisladas de pacientes de las Unidades de Cuidados Intensivos.

The indiscriminate use of antibiotics in intensive care units has permitted the selection of multiple resistant bacterial strains in the hospital setting. Antibiograms present the sensitivity or resistance of these strains to drugs in current use. In this study, 100 bacterial strains were isolated from patients on medical and surgical ICU wards. The strains were identified by API-20E and sensitivity testing was performed by the E-test procedure. MIC were further analyzed with the WHONET software wich permits the identification of antibiotypes. Acinetobacter anitratus, Pseudomona aeruginosa and Enterobacter cloacae were the most resistant strains. Nine antibiotypes were determinated for A. Anitratus. Predominant strain presented antibiotypes with multiple resistance to ten antibiotics. P. aeruginosa presented 10 antibiotypes, the predominant one being CTX, CRO, CTX. Antibiotype determination allows phenotypic identification or resistance patterns in particular species as well as facilitates follow up and recognition of its epidemiological distribution.

Effect of pH of medium and size of inoculum on activity of antibiotics against group D Streptococcus (Enterococcus).

Seventy-one clinical isolates of 5 species of group D Streptococcus (Enterococcus) were tested for susceptibility to 15 antibiotics at pH 5.0, 7.4, and 8.5. Penicillin G, ampicillin, cephalothin, cephaloridine, and novobiocin were considerably more active against all strains at pH 5.0 than in the more alkaline media. On the other hand, lincomycin, clindimycin, erythromycin, and gentamicin were moderately to markedly more active at pH 8.5. No important differences were noted in the susceptibility of the strains to kanamycin and streptomycin, at the pH levels tested, but the organisms were quite resistant to them in these tests. The various species differed quantitatively in their susceptibility to the individual drugs and in the effects of pH. The size of the inoculum also had a variable effect on susceptibility, depending on the species of Enterococcus, the antibiotics, and the pH of the test medium. The data suggest that, in the antibiotic treatment of urinary tract infections caused by Enterococcus, attempts should be made to achieve the optimum pH in the urine, particularly in view of the fact that organisms of this group are often resistant to several antibiotics in the usual tests.