Micologia medica

Effect of metabolic substances of oral Actinomyces on Candida albicans
Susana Gutiérrez de Annan y Laura Benito de Cárdenas
Cátedra de Microbiología y Parasitología, Facultad de Odontología, Universidad Nacional de Tucumán,
San Miguel de Tucumán, Argentina

ABSTRACT.
Actinomyces naeslundii, Actinomyces viscosus and Candida albicans are associated with root cavity. The aim of this study was todetermine, in vitro,the effect produced by the metabolic substances elaborated by ctinomyces naeslundii and Actinomyces viscosus on Candida albicans. The strains were isolated of saliva. There were used the double plaque diffusion method (DPDM) and the method of radial diffusion (MRD). The effect of the time of incubation and of different concentrations of metabolic substances elaborated byActinomyces naeslundii and Actinomyces viscosus on the kinetics of growth of C. albicans were studied. Later, the nature of the substances produced by the two strains of Actinomyces was determined. It was found that there was no inhibition of the growth of C. albicans by A. naeslundii and A. viscosus in the DPDM and the MRD. There was stimulation of the growth of C. albicans by the two strains ofActinomyces when the DPDM was used. In the MRD the results were negative. Metabolic substances produced by both species stimulated the growth of C. albicans in low concentrations but at high concentrations inhibition was observed. The best concentration of the stimulating factor, a protein substance stable to 70 °C, corresponds to a dilution of 1/80. The inhibition of the growth of C. albicans was producedby the decrease of the pH, the higher effect being obtained with the dilution 1/5. The metabolic substances produced by A. naeslundii and A. viscosus can have both inhibitory and stimulant effects on C. albicans, according to their concentration. These metabolic interactions would condition the proportion of C. albicans in the oral microbial ecosystems.

Dirección para correspondencia:
Dra.Susana Gutiérrez de Annan
Cátedra de Microbiología y Parasitología
Facultad de Odontología
Universidad Nacional de Tucumán
Benjamín Araoz 800, San Miguel de Tucumán
CP T4000FUU, Argentina
Teléfono: 054 0381 226421. Int 454
Correo electrónico: sannan@fo.unt.edu.ar
sannan@arnet.com.ar
Aceptado para publicación el 15 de enero de 200 Palabras clave: Actinomyces, Candida albicans, Interaccionesmicrobianas
©2004 Revista Iberoamericana de Micología Key words Actinomyces, Candida albicans, Microbial interactions
Apdo. 699, E-48080 Bilbao (Spain)
1130-1406/01/10.00 Euros

Rev Iberoam Micol 2004; 21: 29-34.

In the oral cavity can live a great variety of microorganisms that constitute the human microbiota. This allows a large amount of oral microbial species can bind to hard surfaces and survivein the oral environment. Those that can adhere and colonize the enamel as treptococcus mutans, Streptococcus sobrinus, Actinomyces naeslundii, Actinomyces viscosus and Candida albicans can grow and multiply to produce caries if environmental conditions permit. These species live in the supragingival plaque biofilm can interact with each other producing bacterial interactions and metabolicinteractions. These interactions are complex and occur in a given time, leading to what is known as autogenic succession. The genus Actinomyces is present in significant proportions in the normal microbiota of the oral cavity A. naeslundii and A. viscosus are associated with root surface caries. The Actinomyces fimbriae possess that enable adherence to hard surfaces and mucous membranes of the oralcavity and interaction with other oral bacteria. Possess extracellular enzymes used to grow in harsh environments. These enzymes also influence other plaque bacteria, determining the different oral ecological niches. The above features of this kind encourage colonization in the oral cavity plays an important role in the initiation of plaque development.
Oral fungal infections of the genus Candida are...