RESUMO
Two monthly studies on the prevalence of penicillin and erythromycin susceptibility of Streptococcus pyogenes were performed in May and October of 1994 in Argentina. A total of 58 centers from 27 cities participated in these studies. A total of 1072 isolates were tested by a diffusion method, although 595 isolates were tested both by the diffusion and an agar dilution method (n = 1767 isolates). No penicillin-resistant streptococci were found in our study (MIC100 = 0.03 microgram/ml). Only four isolates were confirmed as erythromycin resistant S. pyogenes (prevalence 0.14 and 0.28% in May and October 1994, respectively). Resistance in three isolates was due to an inducible mechanism, although in one strain a different phenotype was observed.
Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , Penicilinas/farmacologia , Streptococcus pyogenes/efeitos dos fármacos , Argentina , Resistência Microbiana a Medicamentos , Testes de Sensibilidade Microbiana , Resistência às Penicilinas , Streptococcus pyogenes/metabolismoRESUMO
The effect of ceftizoxime, a new aminothiazolil-syn-methoxy-iminocephalosporin has been evaluated on 169 strains of Gram negative bacilli isolated from hospitalized patients and compared with that of cefotaxime and of ceftriaxone. The effect of these 3 cephalosporins and of cefalotin was also evaluated on 50 strains of staphylococcus. CIM50 of ceftizoximel was as follows: K. pneumoniae less than .032, aureus and S. epidermidis less than .2 CIM90 for the same species was: K. pneumoniae less than .25, E. coli less than .63, E. Cloacae and S. marcescens less than 8, S. aureus less than 32, S. epidermidis less than 16. The values obtained with cefotaxime and ceftriaxone were similar. Cefalotin was clearly more active on staphylococcus strains with CIM50 and CIM90 for both species of less than .25 and less than .2 respectively.
Assuntos
Ceftizoxima/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Staphylococcus/efeitos dos fármacos , Cefotaxima/farmacologia , Ceftriaxona/farmacologia , Cefalotina/farmacologia , Resistência Microbiana a Medicamentos , Humanos , Técnicas In VitroRESUMO
The effect of ceftizoxime, a new aminothiazolil-syn-methoxy-iminocephalosporin has been evaluated on 169 strains of Gram negative bacilli isolated from hospitalized patients and compared with that of cefotaxime and of ceftriaxone. The effect of these 3 cephalosporins and of cefalotin was also evaluated on 50 strains of staphylococcus. CIM50 of ceftizoximel was as follows: K. pneumoniae less than .032, aureus and S. epidermidis less than .2 CIM90 for the same species was: K. pneumoniae less than .25, E. coli less than .63, E. Cloacae and S. marcescens less than 8, S. aureus less than 32, S. epidermidis less than 16. The values obtained with cefotaxime and ceftriaxone were similar. Cefalotin was clearly more active on staphylococcus strains with CIM50 and CIM90 for both species of less than .25 and less than .2 respectively.
