James W. Bullard

Evaluation of microbial flora found in previously worn prostheses from the Northeast and Southwest regions of the United States

STATEMENT OF PROBLEM Denture-induced stomatitis is a recognized clinical challenge. The responsible microorganisms have not been delineated and may differ among regions of the United States. PURPOSE The purpose of this study was to identify the microorganisms found in dentures from 2 geographic regions. MATERIAL AND METHODS Previously worn dentures from 51 available subjects living in the Southwest (41) and Northeast (10) were aseptically retrieved in sterile plastic bags. A posterior piece of the mandibular denture was removed and sampled on appropriate media under anaerobic conditions. The remaining denture material was divided into 7 equal pieces. Each piece was touched to appropriate aerobic media and incubated at 37 degrees C. Bacteria and yeasts were identified using standard clinical laboratory procedures. Data were analyzed by using descriptive statistics. Denture fragments were further analyzed by scanning electron microscopy (SEM). RESULTS A total of 916 isolates were carried to final speciation. Of these, 711 were aerobic bacteria, 67 were anaerobic bacteria, 125 were yeasts, and 13 were amoebae. Microorganisms were found on the denture surfaces and interstices (denture pores). Most subjects wore their dentures for extended periods without sanitization. SEM analyses confirmed substantial porosity of the denture material with microbial penetration and biofilm formation within the pores. CONCLUSIONS A wide range of potentially pathogenic microorganisms was found in dentures. There were also regional differences in the microbial flora.

Microbiota Found in Protective Athletic Mouthguards

Background: Protective athletic mouthguards (PAM) produce oral mucosal injuries and may be associated with other systemic conditions. Hypothesis: With wear, PAM become contaminated by a range of microorganisms. The number of microorganisms in PAM can be reduced by daily use of an antimicrobial solution. Study Type: Case series. Study Design and Methods: Sixty-two division I football player volunteers were divided into 4 groups, using PAM for varying lengths of time before surrendering them for microbial analysis. One group had their PAM soaked in an antimicrobial solution between uses. The PAM were analyzed qualitatively and quantitatively for bacteria, yeasts, and fungi, using previously accepted methods. Results: The 62 football players surrendered a total of 81 PAM for microbial analysis. The PAM yielded 154 gram-positive cocci, 150 gram-positive bacilli, 21 gram-negative cocci, 31 gram-negative bacilli, 22 yeasts, and 107 molds. The most common species of gram-positive cocci were Staphylococcus spp. and Micrococcus spp. Only 3 PAM (4%) were positive for Staphylococcus aureus. The most common species of gram-positive bacilli were Brevibacterium spp. and Cellulomonas spp. The most common species of yeasts were Candida parapsilosis and Rhodotorula mucilaginosa, while the most common species of mold were Cochliobolus spp. and Penicillium chrysogenum. Soaking the PAM in an antimicrobial solution between uses substantially reduced the numbers of microorganisms. Conclusions: Substantial microbial contamination of PAM occurs with use. The microbial load can be reduced by soaking in an antimicrobial solution between uses. Clinical Relevance: PAM are contaminated by microorganisms that have the potential to produce oral and systemic diseases. They should be sanitized daily and changed when they become sharp and/or jagged.

Protective Athletic Mouthguards: Do They Cause Harm?

Background: Protective athletic mouthguards (PAMs) have been worn in competitive sports for more than 100 years. Today, participants in contact and noncontact sports wear PAMs. Hypothesis: Wearing a PAM produces oral injury. Study Type: Case series. Study Design and Methods: Sixty-two Division I football players voluntarily participated in the study. Before the beginning of the season, each player underwent a thorough oral examination, and all abnormal oral findings were photographed (hyperkeratosis, erythema, ulceration, and combinations thereof). At midseason, 14 players were given complete oral examinations, with all abnormal oral findings documented. At season end, all remaining players (n = 53) had complete oral examinations and photographs taken of abnormal oral findings. Results: The preseason examination of 62 players found a total of 85 lesions (1.4 lesions per player) on the gingiva (n = 17), buccal mucosa (n = 60), and palate (n = 8). The 14 midseason players had 28 lesions (2.0 lesions per player) on gingiva (n = 8), buccal mucosa (n = 16), and tongue (n = 4). At season end, the 53 remaining players had 198 lesions (3.7 per player) on the gingiva (n = 96), buccal mucosa (n = 79), tongue (n = 18), and palate (n = 5). In addition, the lesion intensity scores progressively increased over the season. Because the palate did not come into direct contact with the PAM, it was used as an internal control. Conclusion: The wearing of a PAM may increase the number and intensity of oral mucosal injuries, which may cause localized soft tissue reactions such as hyperkeratosis, erythema, and ulceration. Clinical Relevance: Because the PAM reduces tooth injury but may cause oral lesions, it should be sanitized daily and changed regularly and replaced whenever it becomes sharp and jagged or when the athlete develops an irritation in the mouth.

Cell envelope phospholipid composition of Burkholderia multivorans.

Burkholderia multivorans causes opportunistic pulmonary infections in cystic fibrosis and immunocompromised patients. The purpose of the present study was to determine the nature of the phospholipids and their fatty acid constituents comprising the cell envelope membranes of strains isolated from three disparate sources. A conventional method for obtaining the readily extractable lipids fraction from bacteria was employed to obtain membrane lipids for thin-layer chromatographic and gas chromatography-mass spectrophotometric analyses. Major fatty acid components of the B. multivorans readily extractable lipid fractions included C16:0 (palmitic acid), C16:1 (palmitoleic acid), and C18:1 (oleic acid), while C14:0 (myristic acid), ΔC17:0 (methylene hexadecanoic acid), C18:0 (stearic acid), and ΔC19:0 (methylene octadecanoic acid) were present in lesser amounts. Fatty acid composition differed quantitatively among strains with regard to C16:0, C16:1, ΔC17:0, C18:1, and ΔC19:0 with the unsaturated:saturated fatty acid ratios being significantly less in a cystic fibrosis type strain than either environmental or chronic granulomatous disease strains. Phospholipids identified in all B. multivorans strains included lyso-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol in similar ratios. These data support the conclusion that the cell envelope phospholipid profiles of disparate B. multivorans strains are similar, while their respective fatty acyl substituent profiles differ quantitatively under identical cultivation conditions.

Triclosan-Induced Modification of Unsaturated Fatty Acid Metabolism and Growth in Pseudomonas aeruginosa PAO1

Triclosan is a broad-spectrum antimicrobial agent having low toxicity which facilitates its incorporation into numerous personal and health care products. Although triclosan acts against a wide range of gram-positive and gram-negative bacteria by affecting fatty acid biosynthesis, it is ineffective against the opportunistic pathogen Pseudomonas aeruginosa. Wild-type strain P. aeruginosa PAO1 was used as a model system to determine the effects of triclosan on fatty acid metabolism in resistant microorganisms. This was accomplished by cultivating P. aeruginosa PAO1 cultures in the presence of different concentrations of triclosan, monitoring growth rates turbidimetrically, and harvesting in stationary phase. Readily extractable lipids (RELs) were obtained from freeze-dried cells after washing and analyzed using gas chromatography coupled with mass spectrometry. Resultant data demonstrated that triclosan caused dose-dependent increases in the amounts of trans-C16:1 and trans-C18:1 fatty acids, with concomitant decreases in their respective cyclopropyl analogs. Triclosan did not affect the relative concentrations of saturated, cis unsaturated, or the overall ratios of combined C16 to C18 fatty acid species. The readily extractable lipid fractions contained triclosan proportional to triclosan concentrations in the growth media. The presence or absence of triclosan in either liquid or solid media did not affect the antimicrobial susceptibilities of P. aeruginosa PAO1 to a battery of unrelated antimicrobials. Triclosan decreased growth rate in a dose-dependant manner at soluble concentrations. Incorporation of triclosan into the REL fraction was accompanied by increased levels of trans unsaturated fatty acids, decreased levels of cyclopropyl fatty acids, and decrease in growth rate. These alterations may contribute to triclosan resistance in P. aeruginosa PAO1.