The changing face of odontogenic infections.

PURPOSE: The purpose of this investigation was to compare characteristics of patients hospitalized with odontogenic infections during the 1980s to those of the 1990s. PATIENTS AND METHODS: This study was a retrospective record review that compared 2 cohorts of patients admitted to the same institution during two 81-month periods, one decade apart. Admission criteria were face or neck swelling suggesting abscess or cellulitis and one or more of the following: temperature above 38 degrees C, white blood cell (WBC) count greater than 10.8 x 10(3)/microL, or concern about airway compromise. Characteristics reviewed were age, gender, race, admission temperature, admission WBC count, fascial space(s) involved, tooth of etiology, duration of hospitalization, and bacteria isolated. Data were compared for statistical significance (P <.05). RESULTS: No significant differences were found between the 2 cohorts for age, gender, race, admission temperature, admission WBC count, space involvement, or length of stay (P <.05). One tooth (mandibular left first molar) of 52 was involved more frequently in the 1990 group (P <.03). Gram-positive cocci were isolated significantly more frequently from the 1990s patients than from the 1980s patients (P <.03). There were also significant differences (P <.02) between cohorts in the isolation frequency of individual genera, such as alpha-hemolytic Streptococci, coagulase negative staphylococci, Staphylococcus epidermidis, Bacteroides melanogenicus, beta-lactamase positive Bacteroides, Eikenella corrodens, and Neisseria species. Eighty-one percent of the bacteria cultured from the 1990s patients were resistant to one or more common antibiotics; 47% of these organisms were Staphylococcus aureus. CONCLUSION: No clinically significant differences existed in the characteristics of patients hospitalized with odontogenic infections between the 1980s and the 1990s. Although there were differences in the type and prevalence of bacteria isolated, this was probably a result of changes in nomenclature, identification protocols, and isolation techniques.

The influence of a workshop on dental students' perceptions about sexual harassment.

The objective of this study was to determine the effects of a workshop on the sexual harassment perceptions of students at the University of Kentucky College of Dentistry. Responses to a twenty-six-item questionnaire were elicited from 147 first-through fourth-year students before and after they attended a two-hour sexual harassment workshop. Five questions explored students' personal experiences with sexual harassment; twenty-one questions addressed students' attitudes about sexual harassment. The repeated measures option of the SPSS General Linear Model statistical program was used to individually analyze the Likert-type scale response to the twenty-one attitude items for the following variables: gender, year in dental education, and whether respondents had been sexually harassed or had observed harassment of others. Workshop participation significantly changed some student attitudes about sexual harassment regardless of gender, year in dental education, or whether they had been harassed personally or had witnessed harassment of someone else (p < .05). There were also significant gender-related differences in the direction and magnitude of change in pre- versus post-workshop responses to several attitude items (p < .05). Workshop participants were better informed about and more sensitive to a wide range of sexual harassment issues. The workshop empowered students, especially females, to help create an environment that minimizes the probability of sexual harassment. This may be possible because, after the workshop, participants better understood institutional policies and procedures to handle complaints, including provisions for protection from retaliation if they do file a grievance. This knowledge and sensitivity may result in an environment that facilitates the education of beginning general practitioners who are competent, empathetic, and sensitive.

Dental students' sexual harassment experiences and attitudes.

The objective of this study was to describe the sexual harassment experiences and attitudes of students at the University of Kentucky College of Dentistry. A twenty-six-item questionnaire was developed and administered to 170 dental students in years one through four of the curriculum. Five questions explored students' personal experiences with sexual harassment--whether they had been harassed or had observed harassment; twenty-one questions addressed students' attitudes about sexual harassment. Computations of mean differences in Likert-type scale responses for the twenty-one attitude items were completed using independent t-tests for the following variables: gender, whether respondents had been sexually harassed or had observed harassment of others, and years in dental education. Almost 15 percent of the students reported being sexually harassed at least once in dental college. Females were sexually harassed more often than males (p < .01), and second, third, and fourth year students more often than first year students (p < .05). Additionally, 30 percent of the students reported witnessing sexual harassment in the college. Harassers included faculty (88 percent), dental students (8 percent), and others (4 percent). Differences (p < .05) in sexual harassment attitudes were found when responses were analyzed by gender, by whether students had been sexually harassed, by whether they had witnessed harassment, and by years in dental education. The data show that sexual harassment occurs in the college. Dental faculty and students could benefit from programs to educate them about sexual harassment, how to prevent it from occurring, and how to respond if they are sexually harassed.

Emergence of gram-negative bacilli in the mouths of bone marrow transplant recipients using chlorhexidine mouthrinse.

PURPOSE/OBJECTIVES: To examine whether use of chlorhexidine (CHX) in stomatitis-prevention regimens following bone marrow transplantation (BMT) enhances the emergence of gram-negative bacilli (GNB) to a degree that exceeds its benefits. DATA SOURCES: Articles, book chapters, and case studies. DATA SYNTHESIS: Despite rigorous topical and systemic antimicrobial therapy, oral opportunistic GNB infections occur following BMT. This is most likely because of low susceptibility of GNB to CHX and not that CHX predisposes patients to these infections or the development of CHX resistant strains. CONCLUSIONS: The benefits of CHX use (e.g. preservation of oral mucosa and broad-spectrum antibacterial and antifungal effects) outweight the risks of GNB infection. IMPLICATIONS FOR NURSING PRACTICE: Routine clinical and microbiologic monitoring of the oral cavity are essential with use of CHX. Stomatitis care standards and patient instructions following discharge are included.

Oral Candida albicans in bone marrow transplant patients given chlorhexidine rinses: occurrence and susceptibilities to the agent.

The tongue and buccal mucosa of 26 bone marrow transplant recipients given three 0.12% chlorhexidine digluconate (CHX) oral rinses daily for 8 weeks were sampled weekly for oral Candida albicans. Putative C. albicans colony-forming units on selective bismuth sulfite glucose glycine yeast agar plates were identified with the API 20C system. The CHX minimum inhibitory concentrations (MICs) of oral C. albicans isolates obtained at all 8 sample weeks was determined with a microbroth dilution sensitivity assay. The CHX MIC range for yeast isolates selected randomly at all sample weeks was up to 2.5 to up to 20 micrograms/ml (mean MIC less than or equal to 8.5 micrograms/ml). The CHX MIC range for isolates at week 1 was less than or equal to 5 to less than or equal to 10 micrograms/ml (mean MIC less than or equal to 7.9 micrograms/ml) compared with less than or equal to 2.5 to less than or equal to 20 micrograms/ml at week 8 (mean MIC less than or equal to 8.8 micrograms/ml). Therefore the persistence of oral C. albicans in bone marrow transplant recipients using CHX rinses was due neither to low CHX susceptibilities nor to the development of resistance to the agent.

In vitro effect of chlorhexidine and amikacin on oral gram-negative bacilli from bone marrow transplant recipients.

Prophylactic use of chlorhexidine (CHX) mouthrinses has been shown to benefit the oral health status of bone marrow transplant recipients and other immunosuppressed persons and to reduce systemic complications of oral origin. However, a problem that often emerges with these patients is oropharyngeal and lower respiratory tract colonization by opportunistic aerobic or facultative gram-negative bacilli (GNB). Trends in four studies indicated that CHX rinses may predispose these persons to oral colonization by GNB such as the enterobacteria, Klebsiella pneumoniae and Enterobacter cloacae. Since GNB are generally susceptible to broad-spectrum aminoglycoside antibiotics such as amikacin, the in vitro sensitivities of K. pneumoniae, E. cloacae, Pseudomonas aeruginosa, and Escherichia coli ATCC reference strains and K. pneumoniae and E. cloacae oral clinical isolates to combinations of CHX and amikacin were determined by means of a disk diffusion sensitivity assay on Mueller-Hinton agar. The amikacin minimum inhibitory concentrations for all GNB tested were much lower (less than or equal to 4.69 to less than or equal to 9.37 micrograms/ml) than those for CHX (less than or equal to 18.75 to less than or equal to 300 micrograms/ml), and combinations of CHX and amikacin gave larger growth inhibition zones than CHX alone. No antibacterial antagonism between CHX and amikacin was found, and their solubilities were compatible. Therefore use of topical amikacin in conjunction with CHX rinses may reduce oral colonization by GNB in severely immunocompromised patient populations.

Chlorhexidine prophylaxis for chemotherapy- and radiotherapy-induced stomatitis: a randomized double-blind trial.

Patients receiving cytotoxic antineoplastic therapy often have treatment-associated stomatitis. A 0.12% chlorhexidine digluconate mouthrinse was evaluated (15 ml, three times a day) in a prospective, double-blind randomized trial as prophylaxis against cytotoxic therapy-induced damage to oral soft tissues. Seventy subjects, forty inpatients receiving high-dose chemotherapy and thirty outpatients receiving high-dose head and neck radiation therapy, were evaluated. Chlorhexidine mouthrinse significantly reduced the incidence of oral mucositis in the chemotherapy group on day 14 (p less than 0.02) and at 1 week follow-up on day 28 (p less than 0.002). Mucositis in the patients undergoing chemotherapy who received chlorhexidine also resolved more rapidly. Mucositis severity was significantly less compared to the control chemotherapy group on day 14 (p less than 0.03), day 21 (p less than 0.04), and on 1 week follow-up (p less than 0.02). Concomitant trends in the reduction in oral streptococci and yeast were noted in the chemotherapy group receiving chlorhexidine mouthrinse. Although no differences were observed in oral mucositis between the control and chlorhexidine groups of patients undergoing high-dose radiotherapy, similar reductions of oral microflora to those seen in the chemotherapy population were also noted for patients undergoing radiation therapy who received chlorhexidine. Although generally not significant, some increase in gram-negative bacilli was noted in the chlorhexidine-treated patients in both the chemotherapy and radiotherapy groups, but there was no correlation with increased systemic infection. Prophylactic chlorhexidine mouthrinse reduces oral mucositis and microbial burden in patients with cancer undergoing intensive chemotherapy.

Oral antimicrobial agents--chlorhexidine.

Chlorhexidine's structural characteristics give it potent antimicrobial activity, effectiveness at low concentrations, substantivity that prolongs its therapeutic effect in the oral environment, minimal resorption from the gastrointestinal tract, and the ability to reduce plaque. The use of this agent for oral stomatitis in neoplasia patients has recently been studied. Treatment-associated oral soft tissue inflammation and ulceration were significantly reduced by chlorhexidine in patients undergoing intensive chemotherapy. Reductions in total streptococci and yeast counts were also observed. When used in conjunction with systemic antifungal agents, such as nystatin or clotrimazole, a significantly decreased incidence of clinical oral candidiasis and Candida septicemia was observed. In contrast, in two studies in which high-dose head and neck radiation therapy was applied, there was no reduction in stomatitis. Oral gram-negative bacilli have been shown to increase in high-dose chemotherapy patients who are taking chlorhexidine during the treatment period (3 wk to 2 mo). However, no increase in systemic gram-negative infections or other adverse negative medical consequences were observed. This agent appears to be of therapeutic benefit in reduction of dental plaque, gingivitis, and stomatitis in the high-risk chemotherapy population when used in conjunction with other topical and systemic antimicrobial agents as prophylaxis. Although no toxic or serious adverse effects of chlorhexidine rinse have been observed in the short-term studies to date, the effects of longer-term chlorhexidine administration should be evaluated.

Oral gram-negative bacilli in bone marrow transplant patients given chlorhexidine rinses.

Fifteen bone marrow transplant (BMT) patients who received three 0.12% chlorhexidine digluconate (CHX) mouthrinses daily for eight weeks were monitored weekly for the occurrence of oral opportunistic Gram-negative bacilli (GNB). Tongue and buccal mucosa were sampled with use of Culturette swabs that were streaked on plates containing selective MacConkey agar. After incubation, colony-forming units were scored and putative GNB classified with use of the API 20E rapid identification system and supplemental biochemical tests. After identification, the susceptibilities of all GNB to CHX were determined by means of a disk diffusion sensitivity assay. Sixty-seven percent (10) of the BMT subjects had at least one GNB-positive tongue culture, and 53% (8) had GNB in samples taken from the buccal mucosa. Of 218 samples taken, 26% and 24% from the tongue and buccal mucosa, respectively, were GNB-positive. The predominant clinical GNB isolates were Enterobacter cloacae (46%) and Klebsiella pneumoniac (30%). Their respective CHX minimum inhibitory concentrations (MICs) were similar to those of ATCC reference strains. Although the CHX MIC values of the clinical GNB isolates were high (less than or equal to 37.5 to less than or equal to 300 micrograms/mL), they were not dependent upon length of exposure to the agent. Therefore, changes in sensitivity or resistance to CHX did not appear to occur. The results suggest that the mouths of BMT patients--and perhaps of other immunosuppressed individuals--should be routinely monitored for GNB, as are other clinically important sites, such as the throat and the urinary and gastro-intestinal tracts.

Control of oral mucositis and candidiasis in marrow transplantation: a prospective, double-blind trial of chlorhexidine digluconate oral rinse.

Conditioning chemoradiotherapy damages the mucosal barrier of the mouth and throat and often produces severe oral inflammation and infection. In a prospective, double-blind, randomized study, we examined the use of a chlorhexidine digluconate mouthrinse for prophylaxis against oral mucosal complications in 51 bone marrow transplant patients. Use of chlorhexidine mouthrinse produced significant reductions in the incidence and severity of oral mucositis. Mucositis also resolved more quickly in patients receiving chlorhexidine. Concomitant reductions in total oral streptococci (p less than 0.02-p less than 0.001) and oral candida (p less than 0.004) were seen in patients using chlorhexidine. Persistent clinical oral candidiasis (thrush) was observed in 15 to 27 control group patients (56%), but only transiently in two (8%) of 24 patients who used chlorhexidine rinse (p less than 0.001). Five of 27 control group patients (19%) had candidemia, while no candidemia was observed in the chlorhexidine group (p less than 0.03). Three deaths from disseminated candidiasis occurred in the placebo group; none occurred in patients who received chlorhexidine. Prophylactic use of chlorhexidine mouthrinse produces reductions in oral soft tissue disease and oral microbial burden in patients undergoing bone marrow transplantation. The reductions in mucositis and in oral candida infections observed with prophylactic chlorhexidine mouthrinse represent a significant advantage for patients undergoing marrow transplantation.

Therapeutic use of chlorhexidine in bone marrow transplant patients: case studies.

Patients undergoing cytotoxic chemotherapy and radiation therapy often experience severe oral complications during and after treatment despite supervised oral hygiene and conventional antimicrobial regimens. The antimicrobial compound chlorhexidine is an effective topical prophylactic agent against oral mucositis and candidiasis. Oral mucositis developed in four patients who underwent bone marrow transplantation; the condition was severe enough to prompt use of chlorhexidine. In each case, there was clinical resolution of mucositis and a concomitant decrease in the oral microbial burden 1 week after chlorhexidine use began. This strongly suggests that, in addition to its value in protecting these severely immunocompromised patients from oral infection, chlorhexidine also offers a therapeutic benefit in the resolution of existing oral infections and of mucositis.

Chlorhexidine for prophylaxis against oral infections and associated complications in patients receiving bone marrow transplants.

Intensive chemoradiotherapy damages the mucosal barrier of the mouth and throat and is often associated with severe oral inflammation and infection. This study examined the use of a 0.12% chlorhexidine gluconate mouthrinse for prophylaxis against oral complications in patients receiving bone marrow transplants. Use of chlorhexidine mouthrinse produced reductions in oral soft tissue disease and oral microbial burden, including a significant decrease in oral mucositis and Candida infections. The advantage for patients undergoing intensive antineoplastic therapy, and potentially for other immunocompromised patients susceptible to oral infections, was studied.

A case study of a nontraditional basic science curriculum.

This article presents a critical analysis of the ten-year experience of the Department of Oral Biology of the University of Kentucky College of Dentistry with a nontraditional basic science curriculum. The factors that led to the adoption of this curriculum are outlined, and its effects on students, faculty, and the college's administration are described. The pitfalls inherent in this approach and in the individualized self-instructional format for teaching the basic sciences to dental students are discussed. This critical evaluation is aimed at providing information for those contemplating similar sweeping curricular changes in the future to enable them to make rational decisions and to help them predict the effects of such changes on the educational program.

Energy metabolism in Capnocytophaga ochracea.

Among the microflora of the gingival sulcus are members of the genus Capnocytophaga which have been implicated as possible etiological agents of juvenile periodontitis and systemic infectious diseases. In this study, the pathway used by C. ochracea strain 25 for generating energy from glucose was investigated. When grown in a complex medium supplemented with glucose and NaHCO(3), the major end products formed were acetate (4.6 mmol), succinate (11.0 mmol), pyruvate (4.3 mmol), and oxalacetate (3.6 mmol), and the molar growth yield was 58. Addition of yeast extract to the growth medium caused (i) an increase in acetate (9.2 mmol) and succinate (14.3 mmol), (ii) a decrease in pyruvate (0 mmol) and oxalacetate (1.1 mmol), and (iii) the molar growth yield increased to 75. Glucose was transported by a phosphoenolpyruvate:phosphotransferase system and then catabolized to phosphoenolpyruvate by enzymes of the Embden-Meyerhof-Parnas pathway. No activities were detected for the key enzymes of the Warburg-Dickens, Entner-Douderoff, or hexose phosphoketolase pathways. During growth in the yeast extract-supplemented medium, approximately 37% of the phosphoenolpyruvate carbon was converted to acetate by pyruvate kinase, a pyruvate-decarboxylating enzyme activity, and acetate kinase; the remaining 63% was converted to succinate via phosphoenolpyruvate carboxykinase, malate dehydrogenase, fumarate hydratase, and fumarate reductase.

Carbon dioxide metabolism by Capnocytophaga ochracea: identification, characterization, and regulation of a phosphoenolpyruvate carboxykinase.

Cell suspensions of Capnocytophaga ochracea incorporated [14C]NaHCO3 into a major four-carbon fermentation product, succinate, and cell-free extracts from this organism contained high levels of phosphoenolpyruvate carboxykinase (PEPCK). PEPCK is the major, if not the only, CO2(HCO-3)-fixing enzyme in C. ochracea since cell-free extracts were devoid of pyruvate-dependent and other phosphoenolpyruvate (PEP)-dependent CO2(HCO-3)-fixing enzymes. The reaction products of the enzyme, which was partially purified by diethylaminoethylcellulose column chromatography, were identified as adenosine 5'-triphosphate (ATP) and oxalacetate. The enzyme showed maximum activity when manganese (Mn2+) was the divalent cation in the incubation mixture, and it had an absolute requirement for the nucleoside 5-'diphosphate adenosine 5'-diphosphate (ADP). PEPCK showed a sigmoidal kinetic response to the Mn2+ concentration and homotropic interactions in its kinetic responses to each of its three substrates PEP, ADP, and CO2(HCO-3). The (S)0.5v values for Mn2+, PEP, ADP, and CO2(CHO-3) were approximately 0.08, 0.3, 0.1, and 10 mM, respectively, and Hill coefficients for these same ligands were 2.60, 1.7, 1.9, and 3.0, respectively. In addition, C. ochracea PEPCK is under metabolic control by the nucleoside -5'-triphosphate ATP, and it also showed a sigmoidal kinetic response to this allosteric effector. The Hill coefficient for ATP was 2.70.

Internally generated reduced nicotinamide adenine dinucleotide as a substrate for glycine transport by membrane vesicles of Paracoccus denitrificans.

Internally generated reduced nicotinamide adenine dinucleotide was the most efficient substrate for glycine transport by membrane vesicles of Paracoccus denitrificans.