Evidence that L-(+)-lactate dehydrogenase deficiency is lethal in Streptococcus mutans

26Citations
Citations of this article
14Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

In order to construct an effector strain for the replacement therapy of dental caries, we wished to combine the properties of low-level acid production and high-level colonization potential in a strain of Streptococcus mutans. To this end, we made a deletion in the lactate dehydrogenase (LDH) gene cloned from the bacteriocin-producing S. mutans strain JH1000. However, we were unable to substitute the mutant for the wild-type allele by transformation with linear DNA fragments. The mutated gene, carried on a suicide vector, was shown by Southern analysis to integrate into the JH1000 chromosome to yield transformants carrying both the wild-type gene and mutated LDH gene. Three spontaneous self-recombinants of one heterodiploid strain were isolated by screening 1,500 colonies for a loss of the tetracycline resistance encoded by the gene used to mark the LDH deletion. In all three cases, Southern analysis showed that a loss of tetracycline resistance was accompanied by a loss of the mutated LDH gene, resulting in restoration of the wild-type genotype. However, screening the same number of colonies for self-recombinants that did not make lactic acid during anaerobic growth in Todd-Hewitt broth failed to identify clones in which the wild-type allele was lost. A second, simpler screening of more than 80,000 colonies grown aerobically on glucose tetrazolium medium to identify low-level-acid- producing colonies was also unsuccessful. These results are interpreted as indicating that LDH deficiency is lethal in S. mutans under the cultivation conditions used in these experiments. The physiological bases for this hypothesis are described.

Cited by Powered by Scopus

Biofilms, a new approach to the microbiology of dental plaque

195Citations
N/AReaders
Get full text

Probiotics and oral healthcare

113Citations
N/AReaders
Get full text

Insertional mutagenesis and recovery of interrupted genes of Streptococcus mutans by using transposon Tn917: Preliminary characterization of mutants displaying acid sensitivity and nutritional requirements

112Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Hillman, J. D., Chen, A., Duncan, M., & Lee, S. W. (1994). Evidence that L-(+)-lactate dehydrogenase deficiency is lethal in Streptococcus mutans. Infection and Immunity, 62(1), 60–64. https://doi.org/10.1128/iai.62.1.60-64.1994

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 5

63%

Researcher 2

25%

Professor / Associate Prof. 1

13%

Readers' Discipline

Tooltip

Agricultural and Biological Sciences 4

44%

Medicine and Dentistry 2

22%

Chemistry 2

22%

Social Sciences 1

11%

Article Metrics

Tooltip
Social Media
Shares, Likes & Comments: 8

Save time finding and organizing research with Mendeley

Sign up for free