Estudio de la sensibilidad a los antimicrobianos de patógenos periodontales / Study of antimicrobial susceptibility of periodontal pathogens

Considerando que las diversas fallas en la implementación de la terapia antimicrobiana para el tratamiento de las periodontitis conducen a la aparición de cepas resistentes a los mismos, el objetivo de este trabajo fue realizar un estudio preliminar del patrón de resistencia a los antimicrobianos de uso común en la clínica de cepas de Porphyromonas gingivalis, Prevotella intermedia y Fusobacterium nucleatum. La prueba de sensibilidad a los antimicrobianos se realizó por el método de dilución en agar descrito por la NCCLS (National Committee for Clinical Laboratory Standards). Se probaron antimicrobianos seleccionados entre los más utilizados en la práctica clínica en nuestro medio: amoxicilina, clindamicina, doxiciclina, eritromicina, metronidazol y tetraciclina. Los resultados mostraron que el 100 por ciento de las cepas de P. gingivalisfueron resistentes a metronidazol y sensibles a tetraciclina, y un 33 por ciento sensibles a clindamicina. Las CIMs obtenidas para amoxicilina estuvieron entre 1 y 32 mg/ml, para doxiciclina entre 0,125 y 5 mg/ml y para eritromicina entre 8 y >32 mg/ml. En el caso de P. intermedia, se observó también un 100 por ciento de resistencia a metronidazol, un 67 por ciento de sensibilidad a tetraciclina y un 62,5 por ciento a clindamicina. Las CIMs para amoxicilina estuvieron entre 0,125 y 16 mg/ml, para doxicilina entre 0,125 y 4 mg/ml, y para eritromicina entre 8 y > 32 mg/ml. El 100 por ciento de las cepas de F. nucleatum resultaron sensibles a tetraciclina y resistentes a metronidazol, y el 25 por ciento fueron sensibles a clindamicina. En cuanto a amoxicilina, las CIMs estuvieron entre 0,125 y 16 mg/ml, para doxicilina entre 0,125 y 4 mg/ml, y eritromicina entre 16 y >32 mg/ml. Los patrones de resistencia obtenidos con estas cepas mostraron en general mayores porcentajes de resistencia que lo reportado por otros autores, lo que podría deberse a la falta de políticas de control en el uso de antimicrobianos en nuestro país...

Taking into account that several failures in antibiotic treatments used in periodontitis are driving to the appearance of resistant strains, the aim of this work was to realize a preliminary study of the resistance pattern to commonly used antimicrobials of regional Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum strains. Antibiotic susceptibility test was performed by NCCLS (National Committee for Clinical Laboratory Standards) agar dilution method. Proof antibiotics were selected among the most used in the clinical practice in our region: amoxicillin, clindamycin, doxycycline, erythromycin, metronidazole and tetracycline. The results showed that 100 percent of P.gingivalis strains were resistant to metronidazole and susceptible to tetracycline, and 33 percent susceptible to clindamycin. The MICs obtained for amoxicillin were between 1 and 32 mg/ml, for doxycycline between 0,125 and 5 mg/ml and for erythromycin between 8 and >32 mg/ml. In the case of P. intermedia, were also observed a 100 percent of resistance to metronidazole, 67 percent of susceptibility to tetracycline, and 62,5 percent of susceptibility to clindamycin.. The MICs for amoxicillin were between 0,125 y 16 mg/ml, for doxycycline between 0,125 and 4 mg/ml, and for erythromycin between 8 and >32 mg/ml. 100 percent of F. nucleatum strains were susceptible to tetracycline and resistant to metronidazole, and a 25 percent susceptible to clindamycin. MICs to amoxicillin were between 0,125 y 16 mg/ml, for doxycycline between 0,125 and 4 mg/ml, and to erythromycin between 16 and >32 mg/ml. Resistance patterns obtained with strains of our region showed higher percentages of resistance than those reported by other authors, which might owe to the lack of control politicise for the use of antimicrobials in our country. However, MICs values founded for the 50 and 90 percent of strains are similar to tose reported by NCCLS, except in the case of doxycycline, ...

Correlation between bacterial counts in saliva and subgingival plaque

The aim of this study was to examine the correlation between the number and type of bacteria from periodontal pockets more than 4 mm deep and saliva in 26 patients. Periodontal pocket samples were taken with paper points and transferred to 0.1 ml of enriched thioglicollate broth. Saliva samples were collected simultaneously in aseptic flasks. Both samples were processed within the first hour. They were inoculated in Schaedler agar plus 5 micrograms/ml vitamin K and 5

blood, TSBV agar and MGB agar to perform colony counts and identification. Spirochete counts per microscopic field were obtained by direct light microscopy of Gram-stained preparations. The results show a fair to good correlation between both samples for anaerobic, pigmented gram-negative rods, anaerobic non-pigmented gram-negative rods, spirochetes, facultative gram-negative rods other than Actinobacillus actinomycetemcomitans, anaerobic, gram-positive cocci and anaerobic gram-positive rods (Spearman correlation coefficient 0.51 to 0.96). The correlation coefficient values for A.a., facultative gram-positive rods, facultative gram-positive cocci and facultative gram-negative cocci were lower than 0.21. There were no significant differences between the counts in both samples for all the bacterial groups (Student’s t test, p > 0.1). We may conclude that, under the experimental conditions of the present study, saliva samples and periodontal pocket samples are equally useful to detect subgingival organisms associated with periodontal disease in the oral cavity. Saliva samples were useful to evaluate risk and periodontal therapy in individual patients or groups.

Sindrome de Mallory-Weiss. / MalloryWeiss syndrome

Se presentan 18 pacientes con sindrome de Mallory-Weiss, sobre un total de 240 hemorragias digestivas altas estudadas desde enero de 1976 hasta diciembre de 1980, lo cual representa el significativo porcentaje del 7%.El vomito ha sido el factor desencadenante en casi todos los casos y su frecuencia en alcoholistas ha sido llamativa. Los pacientes fueron tratados medicamente sin excepcion con excelente resultado. Solo un paciente repitio la hemorragia a los 20 dias, pero tampoco fue necesario operarlo. No hay dudas que el uso de la gastroscopia de rutina ha hecho aumentar su frecuencia como causa de hemorragia digestiva alta y esta seguridad en el diagnostico y los buenos resultados obtenidos con el tratamiento medio han disminuido la indicacion quirurgica, que solo se ha dejado para pacientes con hemorragias masivas e incontrolables