Microbiology and epidemiology of oral yeast colonization in hemopoietic progenitor cell transplant recipients.

OBJECTIVE: We monitored the epidemiology and microbiology of oral yeast colonization in patients undergoing hemopoietic progenitor cell transplantation (HPCT) to examine associations between yeast colonization and oral mucositis. STUDY DESIGN: One hundred twenty-one consecutive HPCT patients were sampled for oral yeasts prior to fluconazole (FLC) prophylaxis, at transplantation, and weekly until discharge. Clinical oral mucositis screenings were performed triweekly. RESULTS: Yeast colonization was evident at 216 of 510 total visits. Candida albicans and Candida glabrata were the predominant organisms. Eight patients showed elevated minimal inhibitory concentrations to FLC. One patient developed fungal septicemia. Patients with oral mucositis assessment scale scores <20 had higher colonization rates than those with higher scores. CONCLUSIONS: FLC is effective in controlling a variety of oral yeasts in HPCT recipients. FLC-resistant yeasts do emerge and can be the source of fungal sepsis. A positive association was not shown between yeast colonization and the presence or severity of oral mucositis.

The Changing Epidemiology of Oropharyngeal Candidiasis in Patients with HIV/AIDS in the Era of Antiretroviral Therapy.

The impact of antiretroviral therapy (ART) on opportunistic conditions in HIV patients continues to evolve. We specifically studied the changing epidemiology of oropharyngeal candidiasis (OPC) in 215 HIV/AIDS patients. Status of yeast colonization was assessed from oral rinse samples, and preliminary yeast identification was made using CHROMagar Candida and confirmed with standard microbiological techniques and/or molecular sequencing. Susceptibility to fluconazole was determined by CHROMagar Candida agar dilution screening and CLSI broth microdilution. 176 (82%) patients were colonized and 59 (27%) patients had symptomatic OPC. Candida albicans was the most prevalent species, though C. glabrata and C. dubliniensis were detected in 29% of isolates. Decreased fluconazole susceptibility occurred in 10% of isolates. Previous ART reduced the risk of OPC, while smoking increased the risk of colonization. Oral yeast colonization and symptomatic infection remain common even with advances in HIV therapy. C. albicans is the most common species, but other yeasts are prevalent and may have decreased susceptibility to fluconazole.

Loss of in vitro resistance in Candida glabrata following discontinuation of fluconazole prophylaxis in a hematopoietic stem cell transplantation patient.

We report a case of fluconazole-resistant oropharyngeal colonization caused by a strain of Candida glabrata that rapidly regained susceptibility once prophylaxis with this agent was discontinued and echinocandin therapy was initiated. Isolates collected before and after discontinuation of fluconazole were confirmed to be isogenic by RAPD analysis. Transcription analysis demonstrated constitutive expression of genes encoding efflux pumps in the isolate recovered on fluconazole prophylaxis and transient expression in those isolates collected after fluconazole was discontinued.

Oropharyngeal candidiasis in the era of antiretroviral therapy.

Oropharyngeal candidiasis (OPC) remains a common problem in the HIV-infected population despite the availability of antiretroviral therapy (ART). Although Candida albicans is the most frequently implicated pathogen, other Candida species also may cause infection. The emergence of antifungal resistance within these causative yeasts, especially in patients with recurrent oropharyngeal infection or with long-term use of antifungal therapies, requires a working knowledge of alternative antifungal agents. Identification of the infecting organism and antifungal susceptibility testing enhances the ability of clinicians to prescribe appropriate antifungal therapy. Characterization of the responsible mechanisms has improved our understanding of the development of antifungal resistance and could enhance the management of these infections. Immune reconstitution has been shown to reduce rates of OPC, but few studies have evaluated the current impact of ART on the epidemiology of OPC and antifungal resistance in these patients. Preliminary results from an ongoing clinical study showed that in patients with advanced AIDS, oral yeast colonization was extensive, occurring in 81.1% of the 122 patients studied, and symptomatic infection occurred in one-third. In addition, resistant yeasts were still common, occurring in 25.3% of patients colonized with yeasts or with symptomatic infection. Thus, OPC remains a significant infection in advanced AIDS, even with ART. Current knowledge of the epidemiology, pathogenesis, clinical presentation, treatment, and mechanisms of antifungal resistance observed in OPC are important in managing patients with this infection and are the focus of this review.

Candida krusei sepsis secondary to oral colonization in a hemopoietic stem cell transplant recipient.

Yeasts other than Candida albicans have emerged as important causes of fungal infection in hemopoietic stem cell transplant (HSCT) patients, particularly those receiving fluconazole prophylaxis. We report on an autologous hemopoietic stem cell transplant recipient who developed Candida krusei sepsis from pre-existing oral colonization.

Adult hemopoietic stem cell transplantation.

BACKGROUND: Hemopoietic stem cell transplantation, or HSCT, is an important tool in modern cancer treatment. Refinement of transplantation techniques and supportive care has resulted in increased posttransplantation survival rates. Dental care is a key supportive element in both pretransplantation and posttransplantation care of this patient population. METHODS: The authors provide an overview of HSCT transplantation, emphasizing the oral complications and required supportive dental care. CONCLUSIONS: It is critical that transplantation candidates undergo dental screenings and be treated adequately before transplantation, that their care be closely managed during the transplantation process, and that they be given dental support as soon as their recovery permits. Dentists should consult with the patient's oncologist or primary health provider to identify the appropriate timing and intensity of dental support. CLINICAL IMPLICATIONS: Because of improved transplantation survival rates, more patients may seek supportive outpatient dental care after transplantation, which requires special management considerations. Dental professionals need to be knowledgeable about modern HSCT.