C. albicans Colonization of Human Mucosal Surfaces

Background: Candida albicans is a low level commensal organism in normal human populations with the continuous potential to expand and cause a spectrum of clinical conditions. Methodology/Principal Findings: Using ex vivo human organ cultures and populations of primary human cells, we have developed several related experimental systems to examine early-stage interactions between C. albicans and mucosal surfaces. Experiments have been conducted both with exogenously added C. albicans and with overtly normal human mucosal surfaces supporting pre-existing infections with natural isolates of Candida. Under different culture conditions, we have demonstrated the formation of C. albicans colonies on human target cells and filament formation, equivalent to tissue invasion. Conclusions/Significance: These organ culture systems provide a valuable new resource to examine the molecular and cellular basis for Candida colonization of human mucosal surfaces

Frequency of oral mucositis and microbiological analysis in children with acute lymphoblastic leukemia treated with 0.12% chlorhexidine gluconate

Tendo em vista o potencial de morbidade das complicações orais em pacientes com leucemia, este estudo avaliou as alterações clínicas e microbiológicas que ocorrem na mucosa bucal de crianças com leucemia linfoblástica aguda (LLA), submetidas à quimioterapia antineoplásica e administração profilática do gluconato de clorexidina 0,12%. A amostra foi constituída de 17 crianças de 2 a 12 anos, as quais foram submetidas a exame clínico da mucosa oral para a detecção de lesões bucais. Além disso, foi coletado material biológico das mucosas labial e jugal para análises microbiológicas. A mucosite oral foi observada em apenas 5 (29,4%) pacientes. A análise microbiológica revelou a presença de um número reduzido de microorganismos potencialmente patogênicos, como estafilococos coagulase-negativos (47%), Candida albicans (35,3%), Klebsiella pneumoniae (5,9%), Escherichia coli enteropatogênica (5,9%) e Stenotrophomonas maltophilia (5,9%). Pacientes com mucosite oral apresentaram uma maior freqüência de estafilococos coagulase-negativos (80%) quando comparados aos pacientes que exibiam mucosa oral normal (33,3%). Em conclusão, os resultados do presente estudo sugerem que o uso profilático do gluconato de clorexidina 0,12% reduz a freqüência de mucosite oral e de patógenos orais em crianças com LLA. Além disso, os presentes achados sugerem uma possível relação entre estafilococos coagulase-negativos e o desenvolvimento de mucosite oral. _________________________________________________________________________________________ ABSTRACT: In view of the morbidity potential of oral complications in patients with leukemia, this study evaluated the clinical and microbiological alterations that occur in the oral mucosa of children with acute lymphoblastic leukemia (ALL) undergoing antineoplastic chemotherapy and prophylactic administration of 0.12% chlorhexidine gluconate. The sample consisted of 17 children aged 2 to 12 years that underwent clinical examination of the oral mucosa for the detection of oral lesions. In addition, biological material was collected from labial and buccal mucosa for microbiological analysis. Oral mucositis was observed in only 5 (29.4%) patients. Microbiological analysis revealed a reduced number of potentially pathogenic microorganisms, such as coagulase-negative staphylococci (47%), Candida albicans (35.3%), Klebsiella pneumoniae (5.9%), enteropathogenic Escherichia coli (5.9%), and Stenotrophomonas maltophilia (5.9%). Patients with oral mucositis showed a higher frequency of coagulase-negative staphylococci (80%) when compared with patients with normal oral mucosa (33.3%). In conclusion, the results of the present study suggest that the prophylactic use of 0.12% chlorhexidine gluconate reduces the frequency of oral mucositis and oral pathogens in children with ALL. In addition, the present findings suggest a possible relationship between coagulase-negative staphylococci and the development of oral mucositis

Antimycotic agents in oral candidosis: an overview: 2. Treatment of oral candidosis.

As both humans and fungi are eukaryotic organisms, antifungal agents affect their cellular metabolism. Thus, a relatively few antifungals with minimal toxicity and side-effects are available compared with a plethora of antibacterials. These agents currently prescribed in dentistry belong to two major groups, the polyenes (nystatin and amphotericin B) and the azoles (imidazoles and triazoles). A newly recognized phenomenon known as the post-antifungal effect implies that antifungals, even at sub-therapeutic concentrations, may suppress the virulent attributes of yeasts, especially intra-orally where topical drug levels fluctuate dramatically during dosing intervals.link_to_subscribed_fulltex