ABSTRACT
The acidic capsular polysaccharide isolated from Klebsiella K10 exhibited chromotropic character with respect to induction of metachromasy in the cationic dye pinacyanol chloride (1-ethyl-2-[3-(1-ethyl-2(1H)-quinolylidene)propenyl]quinolinium chloride). Klebsiella K10 polymer consists of hexasaccharide repeating units containing one residue of glucuronic acid along with other neutral sugars in each repeating unit. It induces a metachromatic blue shift in the visible absorption spectrum of the dye from 600 nm to 500 nm. The spectral changes have been studied during interaction of the dye cations with the polyanions at different polymer/dye molar ratios. The polyanion-dye compounds are formed with polymer/dye stoichiometry of 1:1, indicating formation of stacking conformation. The complete reversal of polymer-induced metachromasy has also been observed by the addition of ethanol and urea.
Subject(s)
Carbocyanines/metabolism , Cations , Coloring Agents , Drug Interactions , Hydrogen-Ion Concentration , Klebsiella/analysis , Polysaccharides, Bacterial/pharmacology , Quinolines/metabolismABSTRACT
Foi determinada a concentraçäo inibitória mínima in vitro do ciprofloxacin para cepas de enterobactérias, enterecocos, staphylococcus, Pseudomonas e bactérias anaeróbias estritas isoladas de diversos processos infecciosos de pacientes do Rio de Janeiro, RJ. A maioria das cepas de Escherichia coli e Klebsiella pneumoniae foi inibida com 0,25microng/ml do antimicrobiano, enquanto 1,0microng/ml foi necessário para inibir 90% das cepas de Proteus e Staphylococcus. A CIM90 para cepas de Pseudomonas aeruginosa e Streptococcus faecalis atingiu 2,0microng/ml; no entanto, para bactérias anaeróbias estritas (Bacteroides fragilis e Clostridium perfringens) elevou-se para 16 e 18micron/ml, respectivamente. A análise da curva de morte empregando amostra-padräo de Escherichia coli (ATCC-25922) revelou o efeito bactericida do ciprofloxacin