The identification of bacteria associated with periodontal disease and dental caries by enzymatic methods

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73856/1/j.1399-302X.1986.tb00322.x.pd

Proteolytic profile of Treponema vincentii ATCC 35580 with special reference to collagenolytic and arginine aminopeptidase activity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73401/1/j.1399-302X.1988.tb00096.x.pd

Acidogenic Potential of “Sugar-Free” Cough Drops

A patient presented with extensive marginal ditching around restorations recently placed during whole-mouth rehabilitation. The patient was not xerostomic and was otherwise normal except for the self-reported excessive use of “sugar-free” cough drops sweetened with sorbitol and Isomalt® (an equimolar mix of glucosyl-mannitol and glucosylsorbitol). This prompted an in vitro investigation to determine whether Streptococcus sobrinus 6715, a cariogenic streptococcus, could grow and produce acid in growth medium containing an aqueous extract of such “sugar-free” cough drops. The results indicate that S. sobrinus 6715 uses Isomalt® and sorbitol extensively, producing terminal culture pH as low as 4.2 when grown on medium with cough drop extract containing these sugars. This pH is sufficient to demineralize dental enamel. Patients should be cautioned against the chronic overuse of “sugar-free” cough drops and other “sugar-free” confections sweetened with a mixture of Isomalt® and sorbitol

Hydrolysis of the Leu-Gly bond of phenylazobenzyl-oxycarbonyl- l -Pro- l -Leu-Gly- l -Pro- D -Arg (a substrate of microbial collagenases) by treponemes isolated from the subgingival plaque of periodontitis patients

Cell extracts prepared from several oral treponemes isolated from the subgingival plaque of periodontitis patients showed high enzyme activity toward phenylazobenzyl-oxycarbonyl- l -prolyl- l -leucylglycyl- l -prolyl- d -arginine (a compound used as a substrate for microbial collagenases). One major enzyme hydrolyzing this substrate at the Leu-Gly bond only was partially purified from an unspeciated treponeme (strain US), Treponema denticola ATCC 35405, and 29 different clinical isolates of T. denticola . The Treponema US enzyme also hydrolyzed furylacryloyl- l -leucylglycyl- l -prolyl- l -alanine (another substrate of bacterial collagenases) at the Leu-Gly bond. This enzyme also hydrolyzed various collagens and collagen-derived peptides. These treponemal proteases were sensitive to metal chelators and p -chloromercury compounds. The results indicate that human oral treponemes contain enzymes that readily hydrolyze in chromogenic protease substrates the Leu-Gly bond only that is the cleavage site of these substrates also by “true” microbial collagenases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41336/1/284_2005_Article_BF02094028.pd

New drugs to treat difficult tuberculous and nontuberculous mycobacterial pulmonary disease

Purpose of review Treatment of drug-sensitive tuberculosis (TB) is effective, whereas that of multidrug-resistant and extensively drug-resistant TB as well as nontuberculous mycobacterial (NTM) disease are less so. Therapy in general requires good adherence to potentially toxic drug regimens over prolonged periods. Poor adherence is associated with resistance development and poor outcome. This review will present promising new treatments, both new drugs and regimens, for difficult mycobacterial pulmonary infections. Recent findings A number of new and repurposed drugs including bedaquiline, delamanid, pretomanid, linezolid and clofazimine, and drug regimens, such as the The Evaluation of a Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB (STREAM) trial regimens, are currently progressing from basic research through clinical trials. Summary The role of bedaquiline and delamanid in TB and NTM treatment is still not clearly defined. New and repurposed drugs such as pretomanid, linezolid and clofazimine have the potential to advance TB and NTM treatment. Inhaled liposomal amikacin shows promise in pulmonary NTM disease. Patients with multidrug-resistant TB, extensively drug-resistant TB and NTM disease should be offered the choice to participate in drug trials that may shorten or otherwise improve their experience of treatment. The use of an effective regimen based on appropriate NTM-specific drug susceptibility testing should be a cornerstone of treatment for NTM as much as it is for Mycobacterium tuberculosis treatment. All new drugs identified for Mycobacterium tuberculosis should also be tested for activity against NTM, though robust tools for NTM drug susceptibility testing are required

Black-pigmenting gram-negative bacteria in periodontal disease. II. Screening strategies for detection of P. gingivalis.

The purpose of this analysis was to evaluate the feasibility of detecting P. gingivalis using selected sites and to indicate increased proportions of this organism in periodontitis patients. In 10 patients suffering from moderate to advanced periodontal disease, separate microbiological samples were taken from the mesial, buccal, distal and oral (lingual or palatal) aspects of every tooth. This yielded a total of 927 microbiological samples, 84 to 102 per patient. Three distinct patterns of distribution and relative proportion of P. gingivalis were recognized. In one group of patients, the organism was not cultured. In a second group, few positive sites with low proportions of P. gingivalis were present. A third group of patients yielded high frequencies and proportions of P. gingivalis. The number of samples necessary to diagnose the presence of P. gingivalis at a 95% confidence level varied considerably between the three groups. In 4 patients, sampling 4 randomly selected sites was sufficient, while in the remaining 3 positive patients, 25 or more samples were required to detect the organism with equal certainty. Seven different protocols for multiple subgingival sampling were studied. When considering the number of samples needed to detect the presence of P. gingivalis and to estimate the highest proportion of this organism, selection of the deepest pocket in each quadrant was the most efficient method of sampling.link_to_subscribed_fulltex