ABSTRACT
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, ...
Subject(s)
Humans , Anti-Bacterial Agents/therapeutic use , Periodontitis/diagnosis , Periodontitis/therapy , Microbial Sensitivity Tests/methodsABSTRACT
Veillonella spp. are anaerobic gram-negative cocci associated to oral health. Different types of cultures have been reported for the isolation of these microorganisms. Veillonella spp. colonies produce a red fluorescence, which is made visible through ultraviolet light and disappears in contact with oxygen. This feature would be very useful for rapid presumptive identification. The aims of this study were: 1. to compare the Rogosa selective medium for Veillonella with the cultures recommended by different authors in order to determine best saliva recovery, since this sample is generally used to determine the presence and predominance of this bacteria; 2. to detect red fluorescence production on these different culture media as a rapid method for identification. Selective medium for Veillonella, Schaedler agar for anaerobic bacteria with vitamin K, thioglycollate agar, brain heart infusion agar, Brucella agar, trypticase soy agar, and Columbia agar, all of them with and without the addition of vancomycin, and laked blood were used for this study. The tested sample was a saliva pool. Both, Veillonella colonies, and the total number of microorganisms were counted, and expressed as CFU/ml of saliva. The greatest Veillonella recovery in saliva was obtained with the selective medium for Veillonella with vancomycin and laked blood. The production of fluorescence was only observed in this medium.
ABSTRACT
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 (Students 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.
ABSTRACT
Una de las finalidades del tratamiento odontológico preventivo es reducir el riesgo biológico de caries, lo que debería traducirse desde el punto de vista microbiológico en una disminución en el número de Streptococcus mutans y lactobacilos en cavidad bucal. El objetivo de este trabajo fue evaluar el efecto del tratamiento preventivo en 33 pacientes con edades comprendidas entre 12 y 27 años, a los que se les tomó muestras de placa dental y saliva al iniciar y al finalizar el mismo. Con estas muestras se realizó el recuento simultáneo de Streptococccus mutans y lactobacilos sembrando en un solo medio de cultivo (LAPTg sacarosa 7 por ciento), teniendo en cuenta las diferencias morfológicas de las colonias. La identificación de especies fue confirmada por medio de pruebas bioquímicas. Se observó que el tratamiento odontológico preventivo disminuye significativamente el número de Streptococcus mutans y lactobacilos presentes en la placa dental, mientras que no existe variación en saliva. Se propone el medio de cultivo LAPTg sacarosa 7 por ciento para el aislamiento y recuento simultáneo de Streptococcus mutans y lactobacilos
Subject(s)
Humans , Male , Female , Adolescent , Adult , Dental Caries/prevention & control , Dental Plaque/microbiology , Lactobacillus/isolation & purification , Oral Health/standards , Oral Hygiene , Streptococcus mutans/isolation & purification , Dental Caries/etiology , Treatment OutcomeSubject(s)
Female , Male , Humans , Adolescent , Adult , Colony Count, Microbial/statistics & numerical data , Dental Plaque/microbiology , Saliva/microbiology , Streptococcus mutans/isolation & purification , Streptococcus sanguis/isolation & purification , Anaerobiosis/drug effects , Colony Count, Microbial , Colony Count, Microbial/instrumentation , Culture Media/analysis , Dental Caries/microbiology , Environmental Health , Glucose , Specimen HandlingABSTRACT
The utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). This lactobacillus uses citrate as an energy source in the absence of carbohydrates. External pH and growth increases when citrate is added to complex medium. The presence of citrate does not affect glucose uptake. L. casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control. Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.
ABSTRACT
The utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). This lactobacillus uses citrate as an energy source in the absence of carbohydrates. External pH and growth increases when citrate is added to complex medium. The presence of citrate does not affect glucose uptake. L. casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control. Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.