The effect of a mouthrinse containing essential oils on dental restorative materials.

Mouthrinses that contain essential oils are effective for controlling plaque and periodontal disease. Recent studies have shown that such mouthrinses are effective at preventing the formation of biofilm in dental unit waterlines. However, there is no information in the literature regarding the effect of such mouthrinses on restorative materials used within the oral cavity. Specimens of three common restorative materials (a glass ionomer, a composite resin, and amalgam) were subjected to continuous exposure to Listerine and distilled water for 10 days; at that time, the strength, fluid sorption, and surface appearance of the specimens were compared. Specimens of the test materials also were placed in intraoral devices; volunteer patients wore these devices for 12 hours per day for a period of 10 days. During that time, the patients were instructed to rinse twice daily for 30 seconds with Listerine Cool Mint or a non-active mouthrinse. After 10 days, the specimens were salvaged from the devices and inspected by visible and SEM examination. This study indicates that routine use of mouthrinses containing essential oils (or even prolonged exposure to such mouthrinses) has no adverse effects on restorative materials that might be expected to react to such mixtures because of their chemical compositions. It was concluded that active mouthrinses do not appear to have any adverse effects on a variety of restorative biomaterials.

Effect of farnesol on Staphylococcus aureus biofilm formation and antimicrobial susceptibility.

Staphylococcus aureus is among the leading pathogens causing bloodstream infections able to form biofilms on host tissue and indwelling medical devices and to persist and cause disease. Infections caused by S. aureus are becoming more difficult to treat because of increasing resistance to antibiotics. In a biofilm environment particularly, microbes exhibit enhanced resistance to antimicrobial agents. Recently, farnesol was described as a quorum-sensing molecule with possible antimicrobial properties. In this study, the effect of farnesol on methicillin-resistant and -susceptible strains of S. aureus was investigated. With viability assays, biofilm formation assessment, and ethidium bromide uptake testing, farnesol was shown to inhibit biofilm formation and compromise cell membrane integrity. The ability of farnesol to sensitize S. aureus to antimicrobials was assessed by agar disk diffusion and broth microdilution methods. For both strains of staphylococci, farnesol was only able to reverse resistance at a high concentration (150 microM). However, it was very successful at enhancing the antimicrobial efficacy of all of the antibiotics to which the strains were somewhat susceptible. Therefore, synergy testing of farnesol and gentamicin was performed with static biofilms exposed to various concentrations of both agents. Plate counts of harvested biofilm cells at 0, 4, and 24 h posttreatment indicated that the combined effect of gentamicin at 2.5 times the MIC and farnesol at 100 microM (22 microg/ml) was able to reduce bacterial populations by more than 2 log units, demonstrating synergy between the two antimicrobial agents. This observed sensitization of resistant strains to antimicrobials and the observed synergistic effect with gentamicin indicate a potential application for farnesol as an adjuvant therapeutic agent for the prevention of biofilm-related infections and promotion of drug resistance reversal.

Prevalence of yeast among children in Nigeria and the United States.

Fungal infections have gained considerable importance over the last decade as a result of significant increase in the incidence of opportunistic and systemic candidosis. Although Candida albicans is the predominant causative agent of candidosis, particularly oral disease, recently an epidemiological trend has been observed where other less pathogenic species of Candida, including the newly characterized species Candida dubliniensis, are emerging as significant opportunistic pathogens. The present study aimed to screen for the presence of C. dubliniensis and to compare the recovery of yeast species from 30 seemingly healthy and 30 HIV-positive children in the United States, as well as from 64 malnourished Nigerian children. Oral samples were cultured for fungal growth, and all germ tube and chlamydospore positive isolates were tested for ability to grow at 45 degrees C to differentiate between C. albicans and C. dubliniensis. All isolates were speciated based on colony color production on CHROMagar medium and sugar assimilation profiles. Among the 30 HIV-positive children, 15 (50%) were positive for fungus; 12 were positive for C. albicans, with one of the latter also positive for Candida glabrata, and three were found to harbor C. dubliniensis. Among the 30 non-HIV-positive children, five C. albicans and four C. dubliniensis isolates were recovered. No C. dubliniensis isolates were recovered from the Nigerian group. However, eight other different yeast species were recovered from 31 (48.4%) of the 64 Nigerian children sampled, with six of them growing a combination of species. In comparing the data from the Nigerian and United States children, the frequency of yeasts in the malnourished Nigerian group was considerably higher. The most striking difference between the two groups was in the variety of the usually less encountered and less pathogenic yeast species recovered from the Nigerian population. The findings support previously reported observations that there may be intrinsic differences between different populations sampled and that malnutrition might favor the presence of yeast species other than C. albicans.

Recovery of Candida dubliniensis and other yeasts from human immunodeficiency virus-associated periodontal lesions.

Oral and subgingival samples from periodontal lesions were collected from 54 human immunodeficiency virus (HIV)-positive and 20 HIV-negative patients and cultured for yeast species. Of the 54 samples cultured from HIV-positive patients, 44 (82%) were positive for yeast species, of which 29 (66%) were subgingival. A total of 19 (48%) patients were positive for Candida dubliniensis, of which 15 (79%) were colonized in subgingival sites. Seven isolates of Candida glabrata, two isolates of Candida parapsilosis, and one isolate of Saccharomyces cerevisiae were recovered. This study reports for the first time the recovery of C. dubliniensis from subgingival intraoral sites and confirms the presence of Candida species in sites of periodontal disease associated with HIV.

Laboratory evaluation of anti-biofilm agents for use in dental unit waterlines.

Dental unit waterline biofilm has been recognized as a potential point of contamination and a risk to patients with any level of immunocompromise. Biofilm in dental unit waterlines, once established, has proven formidable to efforts in disinfection/disruption. This project compared standardized evaluation techniques by assessing the efficacy of a variety of agents that have been reported or suggested as useful in surface disinfection and/or antiseptic protocols. The zones of inhibition, minimum inhibitory/bactericidal concentrations and use-dilution with stainless steel carrier replicates tests assessed the disinfection of planktonic organisms using standardized microbial testing procedures. The disruption and/or disinfection of planktonic and biofilm organisms within naturally occurring dental unit waterlines were evaluated by culture and scanning electron microscopy. The six commercially available antimicrobial agents used to assess the techniques were bleach (sodium hypochlorite), Cavicide, glutaraldehyde, Listerine Antiseptic, Peridex and Sterilex Ultra. Comparisons between the results for each technique evaluated were determined for each product. All six agents demonstrated antimicrobial efficacy at the working concentrations designated by the manufacturers. Biofilm matrix elimination evaluated by scanning electron microscopy found virtually 0% elimination by glutaraldehyde to an estimated 90% elimination by Sterilex Ultra and bleach after one treatment. Treatment with Cavicide, Listerine Antiseptic and Peridex resulted in negligible elimination of the biofilm matrix. For comparability, the use of standardized testing techniques to evaluate a disinfection agent's efficacy against dental unit waterline contamination is essential. This project demonstrates a model system for evaluating disinfection agents potentially useful in the management of dental unit waterline biofilm, and should assist in educating the dental clinician in the appraisal of existing and future product claims.

In vitro studies of the efficacy of antimicrobials against fungi.

OBJECTIVE: The purpose of this study was to compare the efficacy of Listerine Antiseptic, Tartar Control Listerine Antiseptic, and Peridex mouthrinses and a 0.2% chlorhexidine digluconate solution against known pathogenic fungi. STUDY DESIGN: Standardized methods were used to compare the antimicrobial efficacy of the above agents versus representative fungal species. Minimum inhibitory concentration-minimum fungicidal concentrations in macrobroth dilutions, suspension kill-time, and effectiveness against an artificial biofilm-attached population were studied. RESULTS: All antimicrobials tested were effective against the fungal species under investigation at the concentration available commercially. Listerine Antiseptic showed a greater efficacy against attached artificial biofilm populations than the other antimicrobials tested. CONCLUSIONS: Listerine Antiseptic, Tartar Control Listerine Antiseptic, and Peridex mouthrinses show promise as a means to control the pathogenic fungal species under investigation and may have applications to reduce oral colonization.

In vitro effect of oral antiseptics on human immunodeficiency virus-1 and herpes simplex virus type 1.

AIM: The antiviral effectiveness of widely used commercial mouthrinses has not been well studied. A project was undertaken to evaluate and compare the in vitro antiviral effectiveness of essential oil-containing mouthrinses (LA & TLA) and chlorhexidine mouthrinses (PX & CHX) on 2 different enveloped viruses, human immunodeficiency virus (HIV-1) and Herpes simplex virus (HSV-1) McIntyre strain. METHOD: HIV-1(89.6) (1x10(5)/ml) and HSV-1 (1x10(6)/ml) in RPMI-1640 medium were treated with two commercially available forms of LA & TLA (tartar control LA), and 2 formulations of chlorhexidine [(PX), 0.12% chlorhexidine & (CHX), 0.2% chlorhexidine] for 30 sec. The antiviral effect was estimated by inhibition of the syncytia formation or the cytopathic effect (CPE) for HIV-1 on MT-2 cells and by inhibition of the plaque formation for HSV-1 on Vero cell monolayers. RESULTS: Undiluted LA, TLA, PX and CHX completely inhibited both HIV-189.6 and HSV-1 McIntyre strain. PX and CHX inhibited HIV-1 up to 1:4 dilution, whereas, LA and TLA inhibited HSV-1 up to 1:2 dilution. The antiviral effects of LA and TLA were found to be similar and also the antiviral effect of PX and CHX were also found to be comparable. CONCLUSIONS: The methods used in this investigation allow easy and reproducible evaluations of antiviral efficacy. The anti-HIV-1 and anti-HSV-1 effects of LA, TLA, PX and CHX as evidenced in our in vitro study suggest that we should investigate potential in vivo effects during the use of essential oil-containing or chlorhexidine containing products when used by patients as mouthrinses. If the clinical studies confirm the in vitro data, pre-procedural use by clinicians may be beneficial in reducing viral contamination of bio-aerosols during the delivery of dental care.

New assay for measuring cell surface hydrophobicities of Candida dubliniensis and Candida albicans.

Hydrophobic interactions, based on cell surface hydrophobicity (CSH), are among the many and varied mechanisms of adherence deployed by the pathogenic yeast Candida albicans. Recently it was shown that, unlike C. albicans, C. dubliniensis is a species that exhibits an outer fibrillar layer consistent with constant CSH. Previously, C. dubliniensis grown at 25 or 37 degrees C was shown to coaggregate with the oral anaerobic bacterium Fusobacterium nucleatum. C. albicans, however, demonstrated similar coaggregation only when hydrophobic or grown at 25 degrees C. This observation implied that coaggregation of Candida cells with F. nucleatum is associated with a hydrophobic yeast cell surface. To test this hypothesis, 42 C. albicans and 40 C. dubliniensis clinical isolates, including a C. albicans hydrophobic variant, were grown at 25 and 37 degrees C and tested with the established hydrophobicity microsphere assay, which determines CSH levels based on the number of microspheres attached to the yeast cells. The coaggregation assay was performed in parallel experiments. All C. dubliniensis isolates grown at either temperature, hydrophobic 25 degrees C-grown C. albicans isolates, and the C. albicans hydrophobic variant, unlike the 37 degrees C-hydrophilic C. albicans isolates, exhibited hydrophobic CSH levels with the microsphere assay and simultaneously showed maximum, 4+, coaggregation with F. nucleatum. The parallel results obtained for C. dubliniensis using both assays support the use of the CoAg assay both as a rapid assay to determine CSH and to differentiate between C. dubliniensis and C. albicans.

Evaluation of a reformulated CHROMagar Candida.

CHROMagar Candida is a differential culture medium for the isolation and presumptive identification of clinically important yeasts. Recently the medium was reformulated by Becton Dickinson. This study was designed to evaluate the performance of the new formula of CHROMagar against the original CHROMagar Candida for recovery, growth, and colony color with stock cultures and with direct plating of clinical specimens. A total of 90 stock yeast isolates representing nine yeast species, including Candida dubliniensis, as well as 522 clinical specimens were included in this study. No major differences were noted in growth rate or colony size between the two media for most of the species. However, all 10 Candida albicans isolates evaluated consistently gave a lighter shade of green on the new CHROMagar formulation. In contrast, all 26 C. dubliniensis isolates gave the same typical dark green color on both media. A total of 173 of the 522 clinical specimens were positive for yeast, with eight yeast species recovered. The recovery rates for each species were equivalent on both media, with no consistent species-associated differences in colony size or color. Although both media were comparable in performance, the lighter green colonies of C. albicans isolates on the new CHROMagar made it easier to differentiate between C. albicans and C. dubliniensis isolates. In conclusion, the newly formulated Becton Dickinson CHROMagar Candida medium is as equally suited as a differential medium for the presumptive identification of yeast species and for the detection of multiple yeast species in clinical specimens as the original CHROMagar Candida medium.

Cell surface hydrophobicity-associated adherence of Candida dubliniensis to human buccal epithelial cells.

Microbial adherence to mucosal surfaces is an important first step in the initiation of the pathogenic process in the oral cavity. Candida albicans, the most adherent and pathogenic Candida species, utilizes a variety of mechanisms to adhere to human tissues. Although the strongest mechanism of adherence involves mannoprotein adhesins on C. albicans, cell surface hydrophobicity (CSH) plays an important role in the adherence process by providing hydrophobic interactions that turn the initial attachment between the yeast and a surface into a strong bond. Recent cell wall analytical and comparative studies showed that, Candida dubliniensis, unlike C. albicans, possesses cell surface variations that allow it to be constantly hydrophobic, regardless of growth temperature. Based on these observations, the present study was designed to compare the adherence abilities of C. dubliniensis and C. albicans to pooled human buccal epithelial cells (BEC), in regards to their cell surface hydrophobicity. Ten C. albicans and nine C. dubliniensis isolates, as well as the C. albicans hydrophobic variant A9V10 were evaluated for adherence with BEC using visual aggregation in the wells of a microtiter plate and microscopic examination. All 11 C. albicans isolates failed to show adherence to BEC, visually or microscopically, when grown at 37 degrees C. The same isolates, however, showed significant increase in aggregation and microscopic adherence to BEC when grown at 25 degrees C. All C. dubliniensis isolates tested and the A9V10 C. albicans hydrophobic variant resulted in visual aggregation and adhered to BEC when grown at either temperature. The findings from this study show that, based on comparative adherence results and growth temperature changes, C. dubliniensis seems to have greater adherence to BEC than do typical C. albicans strains and that hydrophobic interactions seem to be the mechanism of adherence involved. Although many questions remain to be answered regarding the clinical implications of this observed in vitro enhanced adherence of C. dubliniensis to human BEC, these findings support the establishment of this novel species as a clinically significant yeast.

Enhanced interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha production by LPS stimulated human monocytes isolated from HIV+ patients.

Periodontal disease and tooth loss is a common finding among advanced HIV+ patients. In addition to local oral lipopolysaccharide (LPS) stimulation, systemic up-regulation of monocyte pro-inflammatory cytokine secretion may also be involved in the pathogenesis of HIV disease. A study was undertaken to investigate IL-1beta, IL-6 and TNF-alpha production by resting and LPS stimulated monocytes isolated from HIV+ patients and also to investigate the relationship of the patient's HIV viral load status to the cytokine production. Whole blood samples in EDTA were collected from 39 HIV-1 infected patients and 20 age and sex matched uninfected controls. Plasma was separated by centrifugation. Viral load was determined using a quantitative RT-PCR. Monocytes were isolated by Ficoll-hypaque gradient separation followed by overnight plastic adherence. Cultured monocytes (1x10(6)/ml) were stimulated with LPS (1 microg/ml) of either P. gingivalis or F. nucleatum for 2, 8, 24 and 48 h and supernatant fluids were collected. IL-1beta, IL-6, and TNF-alpha levels in supernatant fluids were estimated by ELISA. Increased overall production of IL-1beta, IL-6 and TNF-alpha by LPS stimulated monocytes isolated from HIV-1 infected patients was observed when compared to HIV-1 uninfected controls. LPS stimulated monocytes from HIV-1 infected patients with high viral load (HVL) produced significant (p<0.05) elevations in these pro-inflammatory cytokines when compared to HIV-1 uninfected controls. Both LPS of P. gingivalis and F. nucleatum produced a comparable cytokine production by monocytes after 8 h of stimulation. These data suggest that enhanced IL-1beta, IL-6 and TNF-alpha is produced by monocytes/macrophages isolated from HVL HIV+ patients and may be involved in the overall pathogenesis of HIV-1 infection.

Retrospective identification and characterization of Candida dubliniensis isolates among Candida albicans clinical laboratory isolates from human immunodeficiency virus (HIV)-infected and non-HIV-infected individuals.

Fungal opportunistic infections, and in particular those caused by the various Candida species, have gained considerable significance as a cause of morbidity and, often, mortality. The newly described species Candida dubliniensis phenotypically resembles Candida albicans so closely that it is easily misidentified as such. The present study was designed to determine the frequency at which this new species is not recognized in the clinical laboratory, to determine the patient populations with which C. dubliniensis is associated, to determine colonization versus infection frequency, and to assess fluconazole resistance. Over a 2-year period, 1,251 isolates that were initially identified as C. albicans by a hospital clinical laboratory were reevaluated for C. dubliniensis by inability to grow at 45 degrees C, colony color on CHROMagar Candida medium, coaggregation assay with Fusobacterium nucleatum, and sugar assimilation profiles (API 20C AUX yeast identification system). A total of 15 (1.2%) isolates from 12 patients were identified as C. dubliniensis. Ten of the patients were found to be immunocompromised (these included patients with human immunodeficiency virus infection or AIDS, cancer patients receiving chemotherapy, and patients awaiting transplantation). Thirteen isolates were highly susceptible to fluconazole (MIC, <0.5 microgram/ml). Three isolates from one patient, genotypically confirmed as the same strain, showed variable susceptibility to fluconazole. The first isolate was susceptible, whereas the other two isolates were dose-dependent susceptible (MIC, 16.0 microgram/ml). These data confirm the close association of C. dubliniensis with immunocompromised states and that increased fluconazole MICs may develop in vivo. This study emphasizes the importance of screening germ-tube-positive yeasts for the inability to grow at 45 degrees C followed by confirmatory tests in order to properly identify this species.

Identification of Candida dubliniensis in a study of HIV-seropositive pediatric dental patients.

PURPOSE: The combination of an immature immune system and suppressed cellular immunity in children with HIV infections provides optimal conditions for rapid disease progression. As a result, pediatric AIDS has become a major epidemiological challenge. Oral fungal colonization remains one of the most common opportunistic infections observed in both adult and pediatric HIV infected patients. Although Candida albicans is the most frequently isolated opportunistic fungal species, a recently characterized Candida species, C. dubliniensis, has gained considerable attention due to its almost exclusive association with HIV-seropositive individuals. The purpose of this study was to prospectively screen for the presence of C. dubliniensis among pediatric HIV+ patients. METHODS: Oral samples taken from twenty-seven children were cultured for the presence of yeast. All positive yeast isolates obtained were screened for the presence of C. dubliniensis by use of tests for germ tube and chlamydospore production, detection of inability to grow at 45 degrees C, by colony color on CHROMagar Candida medium, coaggregation with Fusobacterium nucleatum ATCC 49256 and by the results of sugar assimilation testing with the API 20C AUX yeast identification system. RESULTS: Among the 27 patients tested, 3 patients were found to harbor C. dubliniensis, one of which also grew C. glabrata; 12 patients were colonized with C. albicans, while the remaining 12 patients were negative for yeast. Identification of the three C. dubliniensis isolates was genetically confirmed by electrophoretic karyotyping. All three C. dubliniensis isolates were found to be susceptible to fluconazole (MIC < or = 0.25 ug/ml). CONCLUSIONS: These results confirm the presence of this novel species in a dental pediatric HIV seropositive population and support the need for further investigation into the prevalence and pathogenesis of C. dubliniensis.

Enhanced interleukin 1 beta, interleukin 6 and tumor necrosis factor alpha in gingival crevicular fluid from periodontal pockets of patients infected with human immunodeficiency virus 1.

Loss of periodontal support and eventually tooth loss is a common finding among acquired immunodeficiency syndrome (AIDS) patients. The cause of this destruction may be an increase in periodontal disease activity at sites within the same individual and also may be related to an increase in the pro-inflammatory cytokines, diffused through the gingival crevicular sulcus in AIDS patients. A study was undertaken to determine the relative levels of the pro-inflammatory cytokines, interleukin 1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha (TNF-alpha), in gingival crevicular fluid collected from the deep (> 5 mm periodontal pocket depth) and shallow (< or = 3 mm periodontal pocket depth) periodontal pockets of 39 HIV-1-infected patients and 20 age-, race- and sex-matched uninfected controls. Complete medical history including risk factors such as intravenous drug abuse was taken. Gingival crevicular fluid samples were collected on periopaper strips. Cytokines were estimated by solid-phase enzyme-linked immunosorbent assay. To assess the degree of HIV activity, the viral load of these patients was determined by an Amplicor HIV-1 monitor kit using reverse transcriptase polymerase chain reaction. Gingival crevicular fluid from HIV-1-infected patients showed a two-fold increase in both IL-1 beta and TNF-alpha in deep periodontal pockets in comparison to shallow pockets, whereas IL-6 increased 1.8-fold. There was a significant (P < 0.05) increase in IL-1 beta, IL-6 and TNF-alpha in gingival crevicular fluid (both shallow and deep pockets) from HIV-1-infected patients in comparison to uninfected controls and also significantly elevated in deep versus shallow pockets in these patients. Although IL-1 beta, L-6 and TNF-alpha levels among HIV-1-infected patients with a high viral load (> 10,000 copies/ml) were higher than those from patients with a low viral load (< 400 copies/ml), only the increase in IL-1 beta level associated with deep pockets was significant (P < 0.05). There was also a trend of an increase in all the three cytokines among intravenous drug-abusing HIV-1-infected patients in comparison to non-intravenous drug abusers, but only the difference in IL-1 beta levels from deep pockets reached significance (P < 0.05). These enhanced pro-inflammatory cytokine levels in the gingival crevicular fluid of HIV-positive patients may be an important factor in causing the advanced periodontal lesions sometimes observed in HIV-positive patients.

Disinfection of dental unit waterlines with an oral antiseptic.

The problem of potential pathogens in biofilm within dental unit waterlines is real. Even though some chemical agents can disinfect biofilms, there remains concern that all remnants of the biofilm matrix are not eliminated, even with periodic treatments, and the bacterial populations in dental unit waterlines recur rapidly. Toxic and caustic residual chemicals are also a concern. In multiple trials following overnight treatment of dental unit waterlines with Listerine Antiseptic (LA), recurrence was investigated by evaluating effluent and biofilm specimens by plate culture. The presence or absence of biofilm within the dental unit waterlines was evaluated, pre- and post-treatment, by scanning electron microscopy. Baseline evaluations of dental unit waterlines determined the effluent and biofilm to harbor an average of 1 x 10(5) CFU per ml and 1 x 10(4) CFU per cm2, respectively, prior to treatment. Overnight, 18-hour treatment with LA rendered effluent and biofilm samples free of recoverable bacteria in all cases immediately following treatment. Viable bacteria in the effluent of treated dental unit waterlines recurred to near pre-treatment levels by Day 7. The minimum inhibitory concentrations for each of the recovered isolates did not change following overnight treatment. Repeated overnight treatments at the beginning of a one-week study were effective in inhibiting recurrence of viable bacteria in the biofilm and effluent indefinitely, but still failed to completely remove the biofilm matrix. New tubing treated prior to use and then daily with LA did not develop a detectable biofilm by scanning electron microscopy during the study. One-month long follow-up clinical trials have demonstrated that a maintenance solution of a 1:50 concentration of LA and sterile distilled water in self-contained dental units with new tubing is effective for prolonged periods in maintaining the effluent within the American Dental Association's recommendation for the year 2000 of < 200 CFU per ml. The clinical significance of these findings is that a solution to the problem of dental unit waterline contamination may be currently available. Since antimicrobial LA is safe for patient use, it may be one of the most viable options suggested to date.

Enhanced secretory leukocyte protease inhibitor in human immunodeficiency virus type 1-infected patients.

Secretory leukocyte protease inhibitor (SLPI) has been found to possess activity against the human immunodeficiency virus type 1 (HIV-1) in vitro at physiological concentrations. A study was undertaken to evaluate SLPI levels in human saliva and plasma among HIV-positive (HIV(+)) patients with various HIV-1 viral loads in comparison to uninfected controls. Whole blood in EDTA and unstimulated saliva samples were collected from 37 HIV(+) patients, of whom 20 had a history of intravenous drug abuse (IVDA). Control samples were collected from 20 appropriate age- and sex-matched HIV-1-negative individuals. SLPI was estimated from both saliva and serum samples by an enzyme-linked immunosorbent assay. HIV viral load was determined using a quantitative reverse transcription-PCR. SLPI levels were increased 16.7% in plasma and 10.3% in saliva among HIV(+) patients in comparison to uninfected controls. SLPI levels were increased 5.9% in saliva and 3.9% in plasma among HIV(+) patients with a high viral load (>10,000 copies/ml) as compared to patients with a low viral load (<400 copies/ml). Only 23% of patients with a high viral load used combination therapy with protease inhibitor drugs, whereas 92.9% of HIV(+) patients with a low viral load used protease inhibitors. SLPI levels did not differ significantly among the IVDA patients, patients with different viral loads, or patients using protease inhibitor drugs. There was a statistically significant increase in SLPI levels in saliva among HIV patients in comparison to non-HIV-infected controls. An increase in SLPI levels among HIV(+) patients may be a natural consequence of HIV pathogenesis and an important factor in preventing oral transmission of HIV, but this increase may not be evident during plasma viremia in patients with a high viral load.

Oral Candida dubliniensis as a clinically important species in HIV-seropositive patients in the United States.

OBJECTIVE: Interest in Candida dubliniensis has led to renewed clinical investigations regarding incidence, drug resistance, pathogenesis, and epidemiology of fungal infections in patients with HIV. C dubliniensis phenotypically resembles Candida albicans in many respects, yet it can be identified and differentiated as a unique Candida species by its phenotypic and genetic profiles. The purpose of this study was to prospectively evaluate the prevalence of C dubliniensis in clinical isolates and determine the clinical and demographic characteristics of patients harboring C dubliniensis. STUDY DESIGN: Over a 6-week period, 24 yeast-positive isolates from HIV-positive dental patients were screened for C dubliniensis through use of phenotypic criteria. HIV viral load, CD4 count, and complete oral health evaluations were performed on each patient at the same visit during which the oral fungal surveillance culture was taken. RESULTS: Six isolates from 24 HIV-seropositive and yeast-positive patients were shown to be consistent phenotypically and by electrophoretic karyotyping with the European reference strain of C dubliniensis. Dose-dependent susceptibility to fluconazole was shown in one of the C dubliniensis isolates. Five of the 6 patients demonstrated moderate to high viral loads. General oral health, as evidenced by the presence of advanced periodontal lesions and a high decayed, missing, and filled teeth index (>20), was poor in 3 of the 6 patients with C dubliniensis and 7 of the 18 patients with C albicans. A history of intravenous drug abuse was present in 50% of the C dubliniensis -positive patients, which is representative of the HIV-positive population at the hospital. CONCLUSIONS: In this small sample, C dubliniensis represented 25% of the yeast-positive cultures. The clinical significance of this interesting species in the United States may be related to high viral load, rapid AIDS progression, and/or concomitant oral disease, such as a high caries index or periodontal disease.