Shifts in membrane fatty acid profiles associated with acid adaptation of Streptococcus mutans

Quivey, R

doi:10.1016/s0378-1097(00)00258-5

Cited by 43 publications

(78 citation statements)

References 20 publications

(23 reference statements)

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“…S. mutans strains grown at pH 5 had increased levels of monounsaturated fatty acids and longerchain fatty acids than did those grown at pH 7. In contrast S. sobrinus 6715, which does not adapt well to pH stress, was less capable of changing its membrane composition (187). Acidadapted I. monocytogenes was also more tolerant to nisin and other ionophores than was the nonadapted counterpart (67).…”

Section: Cell Membrane Changesmentioning

confidence: 99%

Surviving the Acid Test: Responses of Gram-Positive Bacteria to Low pH

Cotter

Hill

2003

Microbiol Mol Biol Rev

1,030

828

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Gram-positive bacteria possess a myriad of acid resistance systems that can help them to overcome the challenge posed by different acidic environments. In this review the most common mechanisms are described: i.e., the use of proton pumps, the protection or repair of macromolecules, cell membrane changes, production of alkali, induction of pathways by transcriptional regulators, alteration of metabolism, and the role of cell density and cell signaling. We also discuss the reponses of Listeria monocytogenes, Rhodococcus, Mycobacterium, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus, oral streptococci, and lactic acid bacteria to acidic environments and outline ways in which this knowledge has been or may be used to either aid or prevent bacterial survival in low-pH environments

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Section: Cell Membrane Changesmentioning

confidence: 99%

Surviving the Acid Test: Responses of Gram-Positive Bacteria to Low pH

Cotter

Hill

2003

Microbiol Mol Biol Rev

1,030

828

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“…Dental plaque forms through a sequential events resulting in a structurally and functionally organized species rich microbial community [6,101]. Once plaque forms, its species composition at a site is characterized by degree of stability among the component species.…”

Section: Progression Of Dental Biofilmmentioning

confidence: 99%

Dental Caries: A Microbiological Approach

Yadav¹,

Prakash²

2017

J Clin Infect Dis Pract

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“…It has been established that the F-ATPase is transcriptionally up-regulated during growth at pH values below 7 (16,17). Recently, we have shown that the membrane fatty acid composition of S. mutans changes dramatically during growth at low pH values (7,8,28). In an effort to contribute to the characterization of additional factors involved with the acid adaptation process, we have looked to identify proteins that allow S. mutans to survive and grow in an acidified environment.…”

Section: Discussionmentioning

confidence: 99%

Smx Nuclease Is the Major, Low-pH-Inducible Apurinic/Apyrimidinic Endonuclease in Streptococcus mutans

Faustoferri¹,

Hähn

Weiss

et al. 2005

J Bacteriol

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The causative agent of dental caries in humans, Streptococcus mutans, outcompetes other bacterial species in the oral cavity and causes disease by surviving acidic conditions in dental plaque. We have previously reported that the low-pH survival strategy of S. mutans includes the ability to induce a DNA repair system that appears to involve an enzyme with exonuclease functions (K. Hahn, R. C. Faustoferri, and R. G. Quivey, Jr., Mol. Microbiol 31:1489-1498, 1999). Here, we report overexpression of the S. mutans apurinic/apyrimidinic (AP) endonuclease, Smx, in Escherichia coli; initial characterization of its enzymatic activity; and analysis of an smx mutant strain of S. mutans. Insertional inactivation of the smx gene eliminates the low-pH-inducible exonuclease activity previously reported. In addition, loss of Smx activity renders the mutant strain sensitive to hydrogen peroxide treatment but relatively unaffected by acid-mediated damage or near-UV irradiation. The smx strain of S. mutans was highly sensitive to the combination of iron and hydrogen peroxide, indicating the likely production of hydroxyl radical by Fenton chemistry with concomitant formation of AP sites that are normally processed by the wild-type allele. Smx activity was sufficiently expressed in E. coli to protect an xth mutant strain from the effects of hydrogen peroxide treatment. The data indicate that S. mutans expresses an inducible, class II-like AP endonuclease, encoded by the smx gene, that exhibits exonucleolytic activity and is regulated as part of the acid-adaptive response of the organism. Smx is likely the primary, if not the sole, AP endonuclease induced during growth at low pH values.Streptococcus mutans inhabits dental plaque, where, as a causative agent of dental caries, it creates and survives in an acidic milieu (20). Acidification of plaque is a direct result of the secretion of organic acids, by-products of carbohydrate metabolism by S. mutans and other bacterial inhabitants of the oral cavity. The survival of the microbe in the oral cavity is predicated on its ability to elaborate an acid-adaptive response (30). Since pH values in dental plaque have been reported to be as low as 4.0, the intracellular environment is potentially exposed to acidic conditions (11,12,15), which likely leads to an increased formation of abasic sites in DNA (19). This idea is indirectly supported by our previous observation that the process of acid adaptation in S. mutans also includes expression of a low-pH-inducible apurinic/apyrimidinic (AP) endonuclease (10, 27). These studies suggested that the AP endonuclease activity in S. mutans more closely resembles exonuclease III (Exo III) of Escherichia coli than endonuclease IV (10).Based on this hypothesis, we expected that the gene encoding the AP endonuclease activity in S. mutans would show homology to exoA from Streptococcus pneumoniae and xth from E. coli. In the present study, we have identified and cloned a homologue of the E. coli class II AP endonuclease, exonuclease III, which we have nam...

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Shifts in membrane fatty acid profiles associated with acid adaptation of Streptococcus mutans

Cited by 43 publications

References 20 publications

Surviving the Acid Test: Responses of Gram-Positive Bacteria to Low pH

Surviving the Acid Test: Responses of Gram-Positive Bacteria to Low pH

Dental Caries: A Microbiological Approach

Smx Nuclease Is the Major, Low-pH-Inducible Apurinic/Apyrimidinic Endonuclease in Streptococcus mutans

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