Experimental Caries Induced in Animals by Streptococci of Human Origin.

Abstract

Traditionally, lactobacilli have been considered the principal cause of caries, but recent findings have questioned this concept. Orland ( 1 ) succeeded in producing experimental caries by infecting gnotobiotic rats with a strain of streptococcus. More recently, Fitzgerald et a1 ( 2 ) confirmed these findings, and Fitzgerald and Keyes (3) established the cariogenicity of another strain of streptococcus in hamsters. These 2 strains of streptococci were shown to be host-specific with regard to cariogenicity: the hamster strain (designated HS1) produced caries only in the hamster and not in the rat, and the rat strain (designated FA1) produced caries in the rat and not in the hamster. Fitzgerald and Keyes also demonstrated that experimental dental caries in animals is an infectious and contagious pathological state which could be transmitted from mother to young. *Aided by research grant DE 01519, Nat. Inst. Dental Res., U.S.P.H.S. Studies of cultures from human caries have brought out evidence for the presence of streptococci similar to the HS1 and FA1 strains.Preliminary findings indicate that the human streptococci similar to the HS1 strain may be causally associated with human caries. Studies related to human streptococci similar to FA1 strains are being investigated.Materials and methods. Collection of specimens from human carious lesions. A sterile spoon excavator was used to remove carious material from the depths of lesions in both enamel and dentine from human teeth in situ.This material was inoculated in Todd-Hewitt broth, supplemented with 0.5% lactalbumin hydrolysate and incubated at 37°C for 18-24 hours.Production of antiserum. Rabbits were immunized with a vaccine prepared from heatkilled streptococcal cultures (60OC for 1 hr). The bacterial suspensions were washed twice in saline and adjusted to the density of the

Production of Bacteriocins in a Liquid Medium by Streptococcus mutans

“…Streptococcus mutans is cariogenic in experimental animals (7,8,17) and is believed to be important in the initiation of smooth surface dental caries in humans (5,6,14). Bacteriocins produced by S. mutans are therefore of considerable interest since, by inhibiting other organisms, they may play important roles in establishing and/maintaining this pathogenic species in the oral cavity.…”

Mutanolysin, Bacteriolytic Agent for Cariogenic Streptococci: Partial Purification and Properties

“…We have reported that the culture filtrate of Streptomyces globisporus 1829, a strain isolated from soil, is capable of rapidly lysing cells of cariogenic steptococci isolated from carious lesions in both rodents and humans (24,25). Streptococcus mutans, a type of cariogenic bacteria, has been shown to form dental plaques composed of extracellular polysaccharides of a dextran type and to induce dental caries when inoculated into the oral cavities of experimental animals maintained on a high sucrose diet (5,16,27). Fitzgerald (4) found that in some hamsters receiving dextranase in their drinking water significantly less plaque formation occurred, and fewer dental caries developed than in animals not receiving the enzyme; an attempt has been made to control dental caries by applying dextranase (15,18,21).…”

Distribution of Three Cariogenic Bacteria in Secondary Carious Lesions around Amalgam Restorations

“…Immunofluorescence techniques to identify bacteria in carious dentin have been used in two main different ways: (1) by taking carious dentin samples with a spoon excavator, transferring the sample to a microscope slide and labeling the sample with fluorescent antibodies [Bibby and Hine, 1938;Zinner et al, 1965] and (2) by obtaining very thin sections from extracted carious teeth and labeling the section with fluorescent antibodies [Sumitani et al, 1972;Pekovic et al, 1987]. Kermans et al [1981] used immunolabeling and transmission electron microscopy for the identification of specific microorganisms in thin sections of carious dentin.…”