Susceptibilidad antibiótica in vitro a fluoroquinolonas / In vitro antibiotic susceptibility to fluoroquinolones

RESUMEN

Objetivo: Determinar la susceptibilidad antibiótica de la bacterias obtenidas en cultivos de infecciones oculares en la Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materiales y métodos: Estudio descriptivo retrospectivo de una serie de registros de cultivos de muestras de superficie ocular y líquidos intraoculares del laboratorio OCULAB-FOSCAL en Floridablanca (Colombia) realizados entre enero y diciembre de 2007. Se realizó antibiograma por el método de Kirby-Bauer con sensi-discos impregnados de concentraciones determinadas de antibiótico. Resultados: Se recogieron un total de 352 muestras de los cuales 160 fueron de conjuntiva, 150 fueron de córnea y 42 de líquidos intraoculares. Se recuperó más de un microorganismo en el 45,65% del total de las muestras. El 78,7 y el 18,4% de las bacterias identificadas correspondieron a Gram positivos y a Gram negativos, respectivamente. El 6,3, 8,9, 33,2 y 35,6% de las bacterias Gram positivas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. El 7,4, 16,7, 16,7 y 25,9% de las bacterias Gram negativas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. La resistencia bacteriana global (tanto Gram positivos como Gram negativos) a moxifloxacino fue del 10,15% y a gatifloxacino del 6,46%, siendo esta diferencia estadísticamente significativa (p<0,05)(AU)

ABSTRACT

Objective: To determine the antibiotic susceptibility of bacteria recovered from cultures of ocular infections in the Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materials and methods: Retrospective descriptive study of a series of registries of cultures of samples from ocular surfaces and intraocular fluids from the OCULAB-FOSCAL laboratory in Floridablanca (Colombia) made between January and December of 2007. Antibiotic sensitivity screening by the method of Kirby-Bauer with impregnated Sensi-Discs™ of determined antibiotic concentrations was performed. Results: A total of 352 samples were studied 160 from conjunctiva, 150 from cornea and 42 from intraocular fluids. Of the total of the samples more than one microorganism was recovered 45.65% of the samples. Gram positive and Gram negative bacteria were identified in 78.7 and 18.4%, respectively. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was observed in 6.3, 8.9, 33.2 and 35.6%, respectively, of Gram positive bacteria. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was also observed in 7.4, 16.7, 16.7%and 25.9%, respectively, of Gram negative bacteria. The overall bacterial resistance (Gram positive and Gram negative) to moxifloxacin was 10.15%, and to gatifloxacin it was 6.46%, being which showed a statistically significant difference (P<.05). Conclusions: In our study the development of bacterial resistance to fourth generation fluoroquinolones was demonstrated in ocular samples. However, lower levels of resistance to fourth generation fluoroquinolones compared with that of third and second generation were found, particularly to Gram positive. Gatifloxacin showed lower resistance levels than moxifloxacin. Nevertheless, interpretation of this superiority must be made with caution in the clinical field, since other factors, like tissue penetration and in vivo activity, must be taken into account(AU)