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PubMed2004

Oral manifestations in selective IgA deficiency.

Selective immunoglobulin A (IgA) deficiency is the most common of the primary immunodeficiencies with a frequency of 1/300-1/3000, depending on the screened population. As secretory IgA (SIgA) has a protective role in mucosal surfaces from invasion of microorganisms, it is thought that IgA-deficient subjects are susceptible to periodontal diseases and oral manifestations. Previous studies show contradictory results, concerning the involvement of the individuals' periodontium with IgA deficiency. The aim of this study was to investigate and compare the oral manifestations in IgA-deficient subjects with controls. Eleven selective IgA-deficient subjects aged 3-18 years with serum IgA levels <10 mg dl(-1) and 11 age-sex-matched healthy children as the controls entered the study. Oral mucosal investigation, dental caries, plaque accumulation and periodontal status were assessed. Serum immunoglobulin levels were measured by single radial immunodiffusion (SRID) method. Saliva immunoglobulins and secretory component levels were measured by enzyme linked immunosorbent assay (ELISA) methods. IgA-deficient patients had serum and saliva IgA levels less than 10 mg dl(-1) and 10 microg ml(-1), respectively, but other serum immunoglobulin levels were normal and saliva immunoglobulin M (IgM) levels were increased, compared with controls. There were no significant differences in oral manifestations between IgA-deficient subjects and controls, which may be a result of compensatory increase of saliva IgM or other non-immunological defence factors in saliva. Thus, it is not necessary to evaluate IgA and SIgA in all the patients with oral and dental lesions and it is thought that it is better to investigate other factors.

Adolescent↗
PubMed1997

Porphyromonas gingivalis infection of oral epithelium inhibits neutrophil transepithelial migration.

Periodontal diseases are inflammatory disorders caused by microorganisms of dental plaque that colonize the gingival sulcus and, subsequently, the periodontal pocket. As in other mucosal infections, the host response to plaque bacteria is characterized by an influx of polymorphonuclear leukocytes (PMNs) to the gingival crevice. Neutrophil migration through the epithelial lining of the gingival pocket is thought to be the first line of defense against plaque bacteria. In order to model this phenomenon in vitro, we used the oral epithelial cell line KB and human PMNs in the Transwell system and examined the impact of Porphyromonas gingivalis-epithelial cell interactions on subsequent PMN transepithelial migration. We demonstrate here that P. gingivalis infection of oral epithelial cells failed to trigger transmigration of PMNs. Furthermore, it significantly inhibited neutrophil transmigration actively induced by stimuli such as N-formylmethionyl leucyl phenylalanine, interleukin-8 (IL-8), and the intestinal pathogen enterotoxigenic Escherichia coli. The ability of P. gingivalis to block PMN transmigration was strongly positively correlated with the ability to adhere to and invade epithelial cells. In addition, P. gingivalis attenuated the production of IL-8 and the expression of intercellular adhesion molecule 1 by epithelial cells. The ability of P. gingivalis to block neutrophil migration across an intact epithelial barrier may critically impair the potential of the host to confront the bacterial challenge and thus may play an important role in the pathogenesis of periodontal disease.

Bacterial Adhesion↗
PubMed2005

In vitro antimicrobial and resistance-modifying activities of aqueous crude khat extracts against oral microorganisms.

OBJECTIVES: To assess antimicrobial activities of aqueous crude khat (Catha edulis) extracts against a panel of oral microorganisms and to test their ability to modify bacterial resistance to tetracycline and penicillin in vitro. DESIGN: Lyophilized aqueous extracts were prepared from three khat cultivars. The agar dilution method of the NCCLS was used to test the extracts, at concentrations of 20-1.25 mg/ml, against 33 oral strains. MIC was defined as the lowest concentration at which there was no visible growth. Slight growth was defined as marked growth reduction (MGR). The E-test was used to determine the MICs of tetracycline and penicillin-G for three resistant strains in absence and presence of a sub-MIC of the khat extracts (5mg/ml). RESULTS: Eighteen strains (55%) were sensitive to the extracts (MICs 5-20 mg/ml). Most of these were periodontal pathogens with Porphyromonas gingivalis and Tannerella forsythensis being the most susceptible (MIC 5-10mg/ml). Veillonella parvula, Actinomyces israelii and some streptococci were not sensitive. Except for Lactobacillus acidophilus that showed MGR at 1mg/ml, cariogenic species were neither sensitive. The extracts were active against Streptococcus pyogenes (MIC 10-20 mg/ml) but not against Candida albicans and Staphylococcus aureus. The presence of the khat extracts at a sub-MIC resulted in a 2-4-fold potentiation of the tested antibiotics against the resistant strains. CONCLUSIONS: Khat has water-soluble constituents possessing selective antibacterial activity against oral bacteria. There is preliminary evidence for presence of an antibiotic resistance-modifying component. Further investigation is needed to identify the active components and assess their clinical relevance.

Anti-Bacterial Agents↗
PubMedDate not supplied

Effect of chlorhexidine varnish mouthguards on the levels of selected oral microorganisms in pediatric patients.

PURPOSE: The effect of a chlorhexidine varnish delivery system on the levels of selected oral microorganisms was evaluated in caries active pediatric patients, ages 4 to 12 years old. METHODS: Forty-six patients were enrolled into the study when they had multiple carious surfaces and salivary mutans streptococci (MS) levels higher than 10(4) colony forming units (CFUs) per milliliter. This study incorporated a double-blind design and patients were randomly assigned to either the chlorhexidine treatment group or the placebo group. Complete-arch, vacuum-adapted mouthguards (0.02 in. polypropylene coping material) were custom fabricated and coated internally with either a 3.0% chlorhexidine varnish or a placebo varnish. Two pretreatment paraffin-stimulated saliva samples were obtained for culturing prior to varnish treatment. Saliva samples were also obtained immediately after treatment and once a month for up to three months after wearing the mouthguard appliances. Dental restorations were placed at most of these saliva collection visits. Mouthguards were reportedly worn for an average of 9.7 hours per night for approximately seven nights by 40 subjects (87%). RESULTS: After two months, and after three months, there was a significant reduction in MS levels immediately after the chlorhexidine varnish treatment. Total anaerobic and total facultative bacteria levels were not significantly affected. CONCLUSION: One week of nightly use of the chlorhexidine varnish mouthguard system is effective at reducing the number of MS in caries-active pediatric patients in the mixed and primary dentition for at least three months.

Anti-Infective Agents, Local↗
PubMed1996

Expression of functional Porphyromonas gingivalis fimbrillin polypeptide domains on the surface of Streptococcus gordonii.

Genetically engineering bacteria to express surface proteins which can antagonize the colonization of other microorganisms is a promising strategy for altering bacterial environments. The fimbriae of Porphyromonas gingivalis play an important role in the pathogenesis of periodontal diseases. A structural subunit of the P. gingivalis fimbriae, fimbrillin, has been shown to be an important virulence factor, which likely promotes adherence of the bacterium to saliva-coated oral surfaces and induces host responses. Immunization of gnotobiotic rats with synthetic peptides based on the predicted amino acid sequence of fimbrillin has also been shown to elicit a specific immune response and protection against P. gingivalis-associated periodontal destruction. In this study we engineered the human oral commensal organism Streptococcus gordonii to surface express subdomains of the fimbrillin polypeptide fused to the anchor region of streptococcal M6 protein. The resulting recombinant S. gordonii strains expressing P. gingivalis fimbrillin bound saliva-coated hydroxyapatite in a concentration-dependent manner and inhibited binding of P. gingivalis to saliva-coated hydroxyapatite. Moreover, the recombinant S. gordonii strains were capable of eliciting a P. gingivalis fimbrillin-specific immune response in rabbits. These results show that functional and immunologically reactive P. gingivalis fimbrillin polypeptides can be expressed on the surface of S. gordonii. The recombinant fimbrillin-expressing S. gordonii strains may provide an effective vaccine or a vehicle for replacement therapy against P. gingivalis. These experiments demonstrated the feasibility of expressing biologically active agents (antigens or adhesin molecules) by genetically engineered streptococci. Such genetically engineered organisms can be utilized to modulate the microenvironment of the oral cavity.

Animals↗
PubMedDate not supplied

Stress as a determinant of saliva-mediated adherence and coadherence of oral and nonoral microorganisms.

OBJECTIVE: The mucosal secretory proteins, such as the salivary proteins, play a key role in the acquisition and regulation of the mucosal microflora. Most notably, some microorganisms utilize the host's secretory proteins to adhere to the mucosa; a first step in colonization and infection. The secretory proteins also influence colonization by affecting the binding among microorganisms, a process denoted as coadherence. Previously we reported that acute stressors cause specific changes in saliva composition. The present study investigated to what extent these changes influence saliva-mediated microbial adherence and coadherence (ex vivo). METHODS: Thirty-two male undergraduates provided unstimulated saliva before and during a control condition and two stressors: A memory test and a surgery video presentation. We used saliva-coated microplates to test the adherence of bacteria for which the oral cavity is either a natural reservoir (eg, viridans streptococci) or a portal of entry (eg, Helicobacter pylori). We also tested the saliva-mediated co-adherence between Streptococcus gordonii and the yeast Candida albicans. Correlation analyses were performed to determine the relationships between changes in microbial adherence and the concentrations of potential salivary ligands, viz. cystatin S, the mucins MUC5B and MUC7, S-IgA, lactoferrin, alpha-amylase, and total salivary protein. RESULTS: During the memory test, saliva-mediated adhesion of Streptococcus sanguis, Streptococcus gordonii, and H. pylori increased, whereas the coadherence of C. albicans with S. gordonii decreased. During the surgical video presentation the saliva-mediated adherence of H. pylori, S. sanguis, and Streptococcus mitis increased. These changes were independent of salivary flow rate, but correlated with specific changes in salivary protein composition. CONCLUSION: The results show that even moderate stressors, by altering the activity of the mucosal secretory glands, may affect microbial colonization processes such as adherence and coadherence. This study hereby presents a mechanism by which stress may affect the mucosal microflora and susceptibility to infectious disease.

Adult↗
PubMed2006

Chemokine production by buccal epithelium as a distinctive feature of pediatric Crohn disease.

OBJECTIVES: Inflammatory bowel diseases (IBD) represent an aberrant immune response by the mucosal immune system to luminal bacteria. Because the oral mucosa harbors the first epithelial cells that interact with microorganisms, we assessed the immunologic activity of buccal epithelium in children with IBD and adults with Crohn disease. METHODS: Buccal epithelial cells were obtained from 17 children and 14 adults with Crohn disease, 18 children with ulcerative colitis, and 40 controls. Cells were cultured with and without microbial stimulation. Chemokine levels were determined in culture supernatants by cytometric bead array and enzyme-linked immunoabsorbent assay. CXCL-8 production was studied by immunohistochemical analysis of these cells. CXCL-8 production by lipopolysaccharide stimulated monocyte-derived dendritic cells from these patients was determined. RESULTS: Compared with controls, pediatric ulcerative colitis patients, and adult Crohn disease patients, only in children with Crohn disease did buccal epithelial cells exhibit enhanced production of CXCL-8, CXCL-9, and CXCL-10. In vitro stimulation with lipopolysaccharide or zymosan resulted in a further increase of chemokine levels only in cells from pediatric Crohn disease patients. CXCL-8 production by stimulated monocyte-derived dendritic cells from children with Crohn disease was equal to that of children with ulcerative colitis. CONCLUSIONS: Buccal epithelium of children with Crohn disease is immunologically active, even in the absence of oral lesions. The enhanced chemokine production is associated with pediatric Crohn disease and appears restricted to cells derived from the epithelial barrier. Assessment of chemokine production by buccal epithelial cells may become a new, rapid, noninvasive test for screening and classification of IBD in children.

Adolescent↗
PubMed2005

Human immunodeficiency virus type 1 stimulates the expression and production of secretory leukocyte protease inhibitor (SLPI) in oral epithelial cells: a role for SLPI in innate mucosal immunity.

The innate immune response is a key barrier against pathogenic microorganisms such as human immunodeficiency virus type 1 (HIV-1). Because HIV-1 is rarely transmitted orally, we hypothesized that oral epithelial cells participate in the innate immune defense against this virus. We further hypothesized that secretory leukocyte protease inhibitor (SLPI), a 12-kDa mucosal antiviral protein, is a component of the host immune response to this virus. Here we demonstrated constitutive expression and production of SLPI in immortalized human oral keratinocytes. Brief exposure of cells to HIV-1 BaL and HXB2 significantly increased SLPI mRNA and protein production compared to that in mock-exposed cells (P < 0.01), as evaluated by real-time quantitative reverse transcription-PCR and enzyme-linked immunosorbent assay. HIV-1-mediated stimulation of SLPI occurred at the transcriptional level, was dose and time dependent, was elicited by heat-inactivated and infectious viruses, and did not depend on cellular infection. Experiments with purified retroviral proteins showed that the stimulatory effect was induced specifically by external envelope glycoproteins from HIV-1 and simian immunodeficiency virus. SLPI responsiveness to HIV-1 was also observed in an unrelated oral epithelial cell line and in normal (nonimmortalized) human oral epithelial cells isolated from healthy uninfected gingival tissues. In this first report of SLPI regulation by HIV-1, we show that the expression and production of the antimicrobial and anti-inflammatory protein can be stimulated in oral epithelial cells by the virus through interactions with gp120 in the absence of direct infection. These findings indicate that SLPI is a component of the oral mucosal response to HIV-1.

Cells, Cultured↗
PubMed2002

Fluorescence biodistribution and photosensitising activity of toluidine blue o on rat buccal mucosa.

The antimicrobial activity of toluidine blue O (TBO) in the presence of red light has been demonstrated for a wide range of microorganisms. The response of tissues to TBO-induced photosensitisation is an important factor in assessing the clinical usefulness of this technique for the treatment of infectious diseases. The aims of this study were to determine the effect of TBO-mediated photosensitisation on rat buccal mucosa and the biodistribution of the photosensitiser in this tissue. An aqueous solution of TBO was applied to one side of the buccal mucosa of the animals. A 6 mm diameter area was then exposed to light (633 nm) from a copper vapour pumped-dye laser. The opposite, untreated, side of the buccal mucosa served as a control. TBO concentrations of 25, 50 and 200 microg/ml, laser light doses of 110, 170 and 340 J/cm(2) were assessed. Control groups of animals were subjected to 340 J/cm(2) laser light alone or to 200 microg/ml TBO alone. Serial sacrifices were performed after 72 h to obtain mucosal tissue samples for histological examination. For the determination of TBO biodistribution, additional groups received the same TBO doses and were sacrificed after 1 min or 10 min. Specimens were removed and frozen immediately for digital fluorescence imaging. No necrotic or inflammatory changes were found in the buccal mucosa of the animals with any of the treatments (using up to 200 microg/ml TBO and 340 J/cm(2) laser light). A high TBO fluorescence in the epithelium, particularly in the keratinised layer, with almost no fluorescence in the underlying connective tissue was demonstrated by the digital imaging. The results of this study suggest that TBO-mediated PDT (within the concentrations and light doses tested) could be a safe antimicrobial approach for the oral infections without damaging the adjacent normal tissue.

Animals↗
PubMed1981

Effect of human saliva on glucose uptake by Streptococcus mutans and other oral microorganisms.

We examined the effects of human whole salivary supernatant and parotid fluid on glucose uptake by Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, Staphylococcus aureus, and Escherichia coli. The following three effects of saliva were observed: (i) inhibition of glucose uptake (S. mutans, S. sanguis), (ii) promotion of a transient, rapid (0 to 30 s) burst of glucose uptake (S. mutans, S. sanguis), and (iii) enhancement of glucose uptake (S. mitis, A. viscosus, S. aureus, E. coli). We observed no differences between the effects of whole salivary supernatant and the effects of parotid fluid. Heat treatment (80 degrees C, 10 min) of saliva or the addition of dithiothreitol abolished inhibition of glucose uptake. Supplementation of saliva with H(2)O(2) potentiated inhibition of glucose uptake. S. mitis and A. viscosus, which were stimulated by saliva alone, were inhibited by H(2)O(2)-supplemented saliva; 50% inhibition of glucose uptake by S. mutans and S. mitis required ca. 10 muM H(2)O(2) in 50% (vol/vol) saliva. Loss of the inhibitory action of saliva occurred at about 5% (vol/vol) saliva. Supplementation of saliva dilutions with SCN(-) and H(2)O(2) extended the inhibitory activity to solutions containing ca. 0.2% (vol/vol) saliva. We suggest that the salivary lactoperoxidase-SCN(-)-H(2)O(2) system is responsible for the inhibitory activity of saliva reported here. Furthermore, we concluded that lactoperoxidase and SCN(-) are present in saliva specimens in concentrations that exceed minimal inhibitory levels by factors of ca. 500 and 10 to 20, respectively. The resistance of A. viscosus, S. aureus, and E. coli to the inhibitory potential of saliva alone was probably due to the production of catalase by these organisms. The resistance of S. mitis may have been due to special effects of saliva on H(2)O(2) accumulation by this organism compared with S. mutans and S. sanguis. The basis of saliva-dependent enhancement of glucose uptake and the basis of promotion of a transient, rapid burst of glucose uptake are unknown. The role of the salivary lactoperoxidase-SCN(-)-H(2)O(2) system in the oral microbial ecosystem is discussed.

Actinomyces↗
PubMed1990

A rapid diagnosis of anaerobic infection in the oro-maxillary region by gas-liquid chromatography.

The relationship between volatile fatty acids (VFAs) in pus and infecting bacterial species was examined in order to establish a rapid identification system for anaerobic microorganisms in purulent inflammation in the oro-maxillary region. VFAs were detected by the direct injection of pus into gas-liquid chromatography (GLC). Bacterial examination was carried out by anaerobic culture using blood agar plates. The bacterial identification was carried out mainly according to the VPI manual. Analysis of the direct VFA patterns of each sample resulted in 5 groups. The following bacterial species were the main isolates in each group: Streptococcus intermedius in Group A, Peptostreptococcus micros in Group B, Fusobacterium nucleatum in Group C, Bacteroides gingivalis in Group D, and Peptostreptococcus anaerobius in Group E. The profile of VFAs produced in the PYG culture medium of the above isolated bacteria was compared with the direct VFA patterns. Agreement ratios between direct and PYG VFA patterns were as follows: Group A, 47.1%; Groups B and C, 45.0%; Group D, 87.5%; and Group E, 62.9%. The acetic acid concentration was more than 14 x 10(-4) meq/ml in Group B, the butyric acid concentration was more than 7 x 10(-4) meq/ml in Group C, and the iso-caproic acid concentration was more than 14 x 10(-4) meq/ml in Group E. In these cases, it was found that the agreement ratios between the direct and PYG FVA pattern were high. In Group D, irrespective of the concentration of iso-valeric acid detected, the agreement ratio was very high. The antibiotic susceptibility of the isolates was studied. Efficiency rates of ABPC, PIPC, CCL, CEZ, CMZ, SBT/CPZ, JM, CLDM, MINO and GM were relatively low and resistant rates were high for the gram-negative rods.

Abscess↗
PubMed2006

Antimicrobial peptides versus invasive infections.

It has been estimated that there are more microorganisms within and upon the human body than there are human cells. By necessity, every accessible niche must be defended by innate mechanisms to prevent invasive infection, and ideally that precludes the need for robust inflammatory responses. Yet the potential for pathogens to transcend the integument actively or passively and access the bloodstream emphasizes the need for rapid and potent antimicrobial defense mechanisms within the vascular compartment. Antimicrobial peptides from leukocytes have long been contemplated as being integral to defense against these infections. Recently, platelets are increasingly recognized for their likely multiple roles in antimicrobial host defense. Platelets and leukocytes share many structural and functional archetypes. Once activated, both cell types respond in specific ways that emphasize key roles for their antimicrobial peptides in host defense efficacy: (a) targeted accumulation at sites of tissue injury or infection; (b) direct interaction with pathogens; and (c) deployment of intracellular (leukocyte phagosomes) or extracellular (platelet secretion) antimicrobial peptides. Antimicrobial peptides from these cells exert rapid, potent, and direct antimicrobial effects against organisms that commonly access the bloodstream. Experimental models in vitro and in vivo show that antimicrobial peptides from these cells significantly contribute to prevent or limit infection. Moreover, certain platelet antimicrobial proteins are multifunctional kinocidins (microbicidal chemokines) that recruit leukocytes to sites of infection, and potentiate the antimicrobial mechanisms of these cells. In turn, pathogens pre-decorated by kinocidins may be more efficiently phagocytosed and killed by leukocytes and their antimicrobial peptide arsenal. Hence, multiple and relevant interactions between platelets and leukocytes have immunologic functions yet to be fully understood. A clearer definition of these interactions, and the antimicrobial peptide effectors contributing to these functions, will significantly advance our understanding of antimicrobial host defense against invasive infection. In addition, this knowledge may accelerate development of novel anti-infective agents and strategies against pathogens that have become refractory to conventional antimicrobials.

Animals↗
PubMed2004

Salivary characteristics of children and its relation to oral microorganism and lip mucosa dryness.

The aim of this paper was to present baseline data on various saliva properties among a group of Saudi children aged 5 to 11 years and to study the relationship of these properties to some oral micro-organisms as well as to lip and oral mucosa dryness. The results showed a mean of resting and stimulated flow rate of 0.54 +/- 0.40 and 1.23 +/- 0.59 respectively and mean pH value of 7.27 +/- 0.38 and 7.5 +/- .035 respectively. Fluoride concentration was estimated to be 0.151 +/- 0.07 and 0.145 +/- 0.06 in resting and stimulated saliva respectively. Children with dry lip represented 33.9% of the sample population, whereas, those with dry mucosa represented only 0.8%. No significant sex difference was evident in all parameters. 59.1% of children showed medium buffering capacity in the resting saliva, whereas, the majority of children (73.7%) showed high stimulated buffering capacity. Children showed generally high Lactobacillus counts (Lb) in the resting and stimulated saliva (57.9% and 60.5% of children). The presence of yeast also in resting and stimulated saliva seemed high in general (40% and 53% of children had high count). However, Streptococcus mutans (S. mutans) counts showed no discriminating trend in both types of saliva. The data showed no significant association between flow rate and Lb counts in both resting and stimulated saliva although there was a trend toward higher counts associated with low flow rate. The same trend was observed in resting saliva although not significant. Similarly, low resting buffering capacity was associated with high counts of Lb among a high proportion of children (68.6% of children) although not significant. A significant reverse relation was evident between S. mutans counts and stimulated flow rate (p=0.049). The majority of children with normal level of saliva pH showed no yeast colonization (62.1%). The association was significant (p=.024). Similarly, the same association was observed in the medium and high buffering group (66.2%) (p=.040). It was concluded that salivary Lb count seems to be primarily affected by some local factors other than salivary properties, such as diet. Significant inverse relationship was found between S. mutans and stimulated salivary flow. Children in general showed high percentage of yeast reflecting the affect of poor diet among the studied population group. Buffering capacity and pH had an important role in yeast colonization.

Candida↗
PubMed2004

Bioadhesive, non-drug-loaded nanoparticles as modulators of candidal adherence to buccal epithelial cells: a potentially novel prophylaxis for candidosis.

Adherence of microorganisms, such as Candida albicans, represents the initial step in the establishment of infection and, accordingly, modification of this step represents a method by which the incidence of infection may be reduced. Therefore, this study uniquely examined the effects of polymeric nanoparticles on the adherence of blastospores of C. albicans to human buccal epithelial cells (BEC) in vitro. Poly(propylcyanoacrylate) nanoparticles were produced by emulsion polymerisation using a range of anionic, cationic and non-ionic surfactants, their particle size and zeta potential characterised and incubated with stationary phase blastospores of C. albicans for a defined period. Following this, the surface properties and size of blastospores with adsorbed nanoparticles were characterised. phosphate buffered saline-treated and nanoparticle-treated blastospores were incubated with human BEC for 2 h, following which the number of adherent blastospores was enumerated by light microscopy. The size and zeta potential of the nanoparticles were dependent on the surfactant employed in the manufacture process. Following nanoparticle adsorption, alteration of the zeta potential and an increase in the diameter of blastospores were observed. However, as this increase in diameter was indirectly related to the size of the nanoparticles, this may indicate a preference for the adsorption of smaller particles. In addition, following nanoparticle adsorption, the cell surface hydrophobicity (CSH) of C. albicans blastospores was increased and, importantly, the subsequent adherence to BEC in vitro was reduced. Most notably, the adherence of blastospores that had been treated with nanoparticles (stabilised with docusate sodium) was circa 73% lower than that of untreated blastospores. A moderate correlation between increased CSH and reduced adherence and a low correlation between blastospore zeta potential and adherence were observed, inferring that other mechanisms, most likely stearic hindrance, are responsible for the antiadherent properties of adsorbed nanoparticles. In light of their ability to reduce candidal adherence to BEC, it is suggested that polymeric nanoparticles may be useful in the prophylaxis of candidosis of the oral cavity.

Animals↗
PubMed1999

Coaggregation of Candida dubliniensis with Fusobacterium nucleatum.

The binding of microorganisms to each other and oral surfaces contributes to the progression of microbial infections in the oral cavity. Candida dubliniensis, a newly characterized species, has been identified in human immunodeficiency virus-seropositive patients and other immunocompromised individuals. C. dubliniensis phenotypically resembles Candida albicans in many respects yet can be identified and differentiated as a unique Candida species by phenotypic and genetic profiles. The purpose of this study was to determine oral coaggregation (CoAg) partners of C. dubliniensis and to compare these findings with CoAg of C. albicans under the same environmental conditions. Fifteen isolates of C. dubliniensis and 40 isolates of C. albicans were tested for their ability to coaggregate with strains of Fusobacterium nucleatum, Peptostreptococcus micros, Peptostreptococcus magnus, Peptostreptococcus anaerobius, Porphyromonas gingivalis, and Prevotella intermedia. When C. dubliniensis and C. albicans strains were grown at 37 degrees C on Sabouraud dextrose agar, only C. dubliniensis strains coaggregated with F. nucleatum ATCC 49256 and no C. albicans strains showed CoAg. However, when the C. dubliniensis and C. albicans strains were grown at 25 or 45 degrees C, both C. dubliniensis and C. albicans strains demonstrated CoAg with F. nucleatum. Heating the C. albicans strains (grown at 37 degrees C) at 85 degrees C for 30 min or treating them with dithiothreitol allowed the C. albicans strains grown at 37 degrees C to coaggregate with F. nucleatum. CoAg at all growth temperatures was inhibited by mannose and alpha-methyl mannoside but not by EDTA or arginine. The CoAg reaction between F. nucleatum and the Candida species involved a heat-labile component on F. nucleatum and a mannan-containing heat-stable receptor on the Candida species. The CoAg reactions between F. nucleatum and the Candida species may be important in the colonization of the yeast in the oral cavity, and the CoAg of C. dubliniensis by F. nucleatum when grown at 37 degrees C provides a rapid, specific, and inexpensive means to differentiate C. dubliniensis from C. albicans isolates in the clinical laboratory.

Amino Acids↗