An Investigation into the Use of Restriction Endonuclease Analysis for the Study of Transmission of Mutans Streptococci

Abstract

Restriction endonuclease analysis (REA) was performed on the total cellular DNA from each of 396 strains of mutans streptococci (1) to determine its potential usefulness for the study of transmission of the organism and (2) to document the proportions and variety of strains harbored by members of a small group of families. The DNA was digested with restriction enzyme EcoRI andlor HindIII, electrophoresed on agarose gels, and the resulting patterns compared. The strains examined included fresh isolates from 58 subjects, including 19 strains from each member offive families. The sensitivity and reproducibility of REA patterns from the mutans streptococci seemed ideal for studies of their epidemiology and transmission. The pattern of each isolate from humans was unique, except for isolates from the same individual or from the same family. REA types from subjects from different families were always heterogeneous. A high frequency of multiple REA types (up to 5) was observed in many subjects. While evidence for intra-familial transmission was obtained, including transmission between spouses, there was also strong evidence offrequent sources of infection outside of the family. Mutations of strains to streptomycin resistance or to lactate dehydrogenase deficiency caused no detectable change in the REA patterns. The lack of plasmids in any of the 57 fresh isolates that were examined for them suggested that they may have contributed little to the heterogeneity of the patterns seen.

Genotypic diversity and virulence factors of Streptococcus mutans in caries-free and caries-active individuals

“…However, the present result was in agreement with earlier reports (Hirose et al 1993;Alaluusua et al 1996;Emanuelsson et al 2003;Napimoga et al 2004). It has been observed that the subjects harbor one to five distinct genotypes of S. mutans at different ages (Alallusuua et al 1996;Emmanuelsson et al 1998;Grönroos et al 1998;Klein et al 2004;Mattos-Graner et al 2001;Caulfield and Walker 1989;Kulkarni et al 1989;Kreulen 1997;Napimoga et al 2004). In the population examined, two individuals had only one genotype in the group caries-free, and only two had as many as five genotypes in the dental caries group.…”

Potential of Diagnostic Microbiology for Treatment and Prognosis of Dental Caries and Periodontal Diseases

“…Following eruption of teeth, the ecological conditions for colonization by mutans streptococci are established. It has been shown that children seem to acquire bacteria from their mother, as evidenced by studies involving the tracing of serotypes, bacteriocin patterns, or, more recently, by restriction endonuclease mapping (Berkowitz and Jordan, 1975;Kulkarni et al, 1989). This concept of vertical transmission within families or populations has strong clinical implications.…”

Dispensable genes and foreign DNA in Streptococcus mutans

“…Genetic fingerprinting techniques have also demonstrated extensive variation within S. mutans. RFLP of S. mutans was introduced by Kulkarni et al (1989), who demonstrated extensive variety in RFLP patterns amongst different isolates and were the first to show that an individual could carry multiple genotypes. They also found evidence of intra-family transmission, and this was extended by others using RFLP to follow transmission from mothers to their infants and to monitor the stability of S. mutans in individual mouths (Li & Caufield, 1995).…”