Steven D Westbrook

University of Texas Health Science Center at San Antonio, San Antonio, TX, United States

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Publications (10)7.43 Total impact

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    ABSTRACT: The goal of this study was to begin to assess the prevalence of oropharyngeal cancer among all oral cancers and thus the potential role of human papillomavirus (HPV) in this disease in the south Texas Region served by the University of Texas Health Science Center at San Antonio (UTHSCSA), and University Health System (UHS) in San Antonio, Texas. This health system represents the largest catchment area for oral cancer serving the south Texas populations, extending from the U.S.-Mexico border, north to Williamson County, west to Eagle Pass, and east to Gonzales County. With the move towards electronic medical records (EMR) nationwide, our team conducted a feasibility study to answer this question utilizing electronic record coding data across both local networks.
    Texas dental journal. 05/2014; 131(5):376-81.
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    ABSTRACT: 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.
    Oral surgery, oral medicine, oral pathology and oral radiology. 01/2013;
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    ABSTRACT: 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.
    AIDS research and treatment 01/2012; 2012:262471.
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    ABSTRACT: Objective: The epidemiology of oral candidiasis (OPC) in HIV/AIDS has evolved since the advent of antiretroviral (ART) therapy in the mid-1990's. Most past studies have used standard microbiological techniques. However, the current epidemiology after 15 years of ART has not been well described . This study was designed to establish the current epidemiology of oral candidiasis in HIV/AIDS using molecular techniques in addition to standard microbiology. Methods: HIV/AIDS patients were eligible for enrollment with CD4+ count <200 and/or symptomatic OPC. Oral rinse samples were obtained from 213 patients and Candida carriage was assessed by conventional microbiological tests and by direct amplification of yeast DNA from oral samples by standard PCR using Candida pan-fungal primers. Species ID was confirmed using CHROMagar Candida, conventional microbiology techniques, and molecular sequencing. Fluconazole (FLU) susceptibility was assessed by using a CHROMagar Candida FLU screen. Results: 176 patients were positive for Candida and 59 had thrush. Median CD4 count was 90 in all positive patients and 67 in those with thrush. Median viral load was 26,600 in all positive patients and 50,350 in those with thrush. C. albicans was the most commonly isolated yeast making up 60 % of the positive isolates. However, non-albicans Candida species were also frequently found particularly C. glabrata (16%) and C. dubliniensis (11%). Decreased susceptibility to fluconazole occurred in 22% of positive patients. Of those isolates from episodes of thrush with decreased susceptibility to FLU, 73% were non-albicans Candida species with 55% being C. glabrata. 58 of 59 thrush patients responded to FLU therapy although doses higher than 200 mg were required in six of the patients. Conclusions: Even with active antiretroviral therapy, OPC remains common in patients with advanced HIV/AIDS. C. glabrata has emerged as a significant cause of OPC episodes with decreased FLU susceptibility. (Supported by NIDCR 5R01-DE018096)
    IADR General Session 2010; 07/2010
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    ABSTRACT: 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.
    Medical mycology: official publication of the International Society for Human and Animal Mycology 05/2010; 48(3):557-60. · 2.13 Impact Factor
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    ABSTRACT: 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.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 02/2010; 109(4):488-95. · 1.50 Impact Factor
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    Infectious Agents and Cancer 01/2009;
  • Biology of Blood and Marrow Transplantation - BIOL BLOOD MARROW TRANSPLANT. 01/2008; 14(2):97-97.
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    ABSTRACT: 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.
    Medical Mycology 04/2007; 45(2):187-90. · 1.98 Impact Factor
  • Steven D Westbrook, Eleonore D Paunovich, Cesar O Freytes
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    ABSTRACT: 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. The authors provide an overview of HSCT transplantation, emphasizing the oral complications and required supportive dental care. 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. 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.
    Journal of the American Dental Association (1939) 10/2003; 134(9):1224-31. · 1.82 Impact Factor