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1.
J Clin Microbiol ; 55(8): 2453-2461, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28566314

RESUMEN

In early Lyme disease (LD), serologic testing is insensitive and seroreactivity may reflect active or past infection. In this study, we evaluated a novel assay for the direct detection of three species of Borrelia spirochetes in whole blood. The T2 magnetic resonance (T2MR) assay platform was used to amplify Borrelia DNA released from intact spirochetes and to detect amplicon. Analytical sensitivity was determined from blood spiked with known concentrations of spirochetes, and the assay's limit of detection was found to be in the single-cell-per-milliliter range: 5 cells/ml for B. afzelii and 8 cells/ml for Borrelia burgdorferi and Borrelia garinii Clinical samples (n = 66) from confirmed or suspected early LD patients were also analyzed. B. burgdorferi was detected using T2MR in 2/2 (100%) of blood samples from patients with confirmed early LD, based on the presence of erythema migrans and documentation of seroconversion or a positive real-time blood PCR. T2MR detected B. burgdorferi in blood samples from 17/54 (31%) of patients with probable LD, based on the presence of erythema migrans without documented seroconversion or of documented seroconversion in patients with a compatible clinical syndrome but without erythema migrans. Out of 21 clinical samples tested by real-time PCR, only 1 was positive and 13 were negative with agreement with T2MR. An additional 7 samples that were negative by real-time PCR were positive with T2MR. Therefore, T2MR enables a low limit of detection (LoD) for Borrelia spp. in whole blood samples and is able to detect B. burgdorferi in clinical samples.


Asunto(s)
Técnicas Bacteriológicas/métodos , Borrelia/clasificación , Borrelia/aislamiento & purificación , Enfermedad de Lyme/diagnóstico , Espectroscopía de Resonancia Magnética/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Borrelia/química , Borrelia/genética , Humanos , Persona de Mediana Edad , Adulto Joven
2.
J Med Genet ; 53(10): 681-9, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27287392

RESUMEN

BACKGROUND: Over 160 disease phenotypes have been mapped to the major histocompatibility complex (MHC) region on chromosome 6 by genome-wide association study (GWAS), suggesting that the MHC region as a whole may be involved in the aetiology of many phenotypes, including unstudied diseases. The phenome-wide association study (PheWAS), a powerful and complementary approach to GWAS, has demonstrated its ability to discover and rediscover genetic associations. The objective of this study is to comprehensively investigate the MHC region by PheWAS to identify new phenotypes mapped to this genetically important region. METHODS: In the current study, we systematically explored the MHC region using PheWAS to associate 2692 MHC-linked variants (minor allele frequency ≥0.01) with 6221 phenotypes in a cohort of 7481 subjects from the Marshfield Clinic Personalized Medicine Research Project. RESULTS: Findings showed that expected associations previously identified by GWAS could be identified by PheWAS (eg, psoriasis, ankylosing spondylitis, type I diabetes and coeliac disease) with some having strong cross-phenotype associations potentially driven by pleiotropic effects. Importantly, novel associations with eight diseases not previously assessed by GWAS (eg, lichen planus) were also identified and replicated in an independent population. Many of these associated diseases appear to be immune-related disorders. Further assessment of these diseases in 16 484 Marshfield Clinic twins suggests that some of these diseases, including lichen planus, may have genetic aetiologies. CONCLUSIONS: These results demonstrate that the PheWAS approach is a powerful and novel method to discover SNP-disease associations, and is ideal when characterising cross-phenotype associations, and further emphasise the importance of the MHC region in human health and disease.


Asunto(s)
Cromosomas Humanos Par 6 , Estudios de Asociación Genética/métodos , Enfermedades del Sistema Inmune/genética , Inflamación/genética , Complejo Mayor de Histocompatibilidad , Polimorfismo Genético , Adulto , Anciano , Femenino , Humanos , Liquen Plano/genética , Masculino , Persona de Mediana Edad , Fenotipo , Población Blanca/genética
3.
J Clin Aesthet Dermatol ; 16(8): 42-43, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37636247

RESUMEN

We report a retrospective chart review of 112 images submitted from 85 patients through the Epic electronic medial record to determine disposition of patient complaints and to estimate cost savings. The study represents a single practice at a tertiary care university practice. Sixty (53.6%) were resolved electronically. The remaining 52 (46.4%) were deemed to require an in-person office visit. Of the 60 electronically resolved, 23 (38.3%) involved reassurance of a self-limited condition while 37 (61.7%) involved prescription management. The encounters resolved through MyChart were not billed and provided a cost savings of $2,052.29 and $4,664.96 for Level 3 and 4 office visit equivalents, respectively, for a total of $6,717.25. Patients needing an office visit were on average seen 18.3 days from the date of photo submission. After adjusting for patient-initiated rescheduling of the earliest appointment date provided, this was slightly reduced to 16.0 days. We observed diagnostic concordance in 88/112 (78.6%) eConsults. Krippendorff's alpha was 0.773 (95% confidence interval of 0.691- 0.846), indicating a tentative conclusion of modest reliability between the two raters.5 Concordance regarding the need for an appointment as determined by the two raters was observed in 71/112 (63.4%) eConsults. We conclude that patient-submitted eConsults is a viable means of resolving just over half of patient-submitted dermatologic concerns while offering cost savings; there is modest inter-rater reliability.

4.
Cureus ; 14(10): e30673, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36439577

RESUMEN

Background and objective Diagnosis of early Lyme disease (LD) often relies on clinical recognition of the skin lesion, erythema migrans (EM), a diagnostic sign of disease when laboratory testing is insensitive. Because EM can present in morphologically distinct forms, its recognition by clinicians can be challenging. This study aimed to characterize the clinical spectrum of lesions in patients presenting with suspected early LD in an ambulatory care setting to identify features that might help clinicians to be better prepared to recognize EM lesions. Methods Images of lesions from 69 participants suspected to have early LD were retrospectively evaluated by a dermatologist and a family practitioner with expertise in early LD. Reviewers made determinations on the diagnoses and morphological features of lesions. Agreement between reviewers and associations among lesion types and participant demographics, symptomology, and laboratory evidence of infection were examined using the kappa statistic and contingency tables, respectively. Results Challenges in diagnosing EM were evident in our study: initial concordance between reviewers was moderate [kappa statistic (95% CI): 0.45 (0.245 - 0.657)]. The final classification included 35 lesions (51%) that were agreed to be EM; 23 lesions (30%) were considered to be possible early EM or tick bite reactions, and 11 (16%) were thought not to be EM, but rather other diagnoses, including ringworm, allergic contact dermatitis, and mosquito bites. Only two lesions (6%) were observed with a classic bull's eye or ring-within-a-ring pattern. Most EM lesions were uniform (51%), pink (74%), oval lesions (63%), with well-demarcated borders (92%). Early EM or tick bite reactions were typically <5 cm in size (74%), red (52%), round lesions (61%), with a punctum present (100%). Lesions thought not to be EM also tended to be pink or red (64%), round (55%), or uniform (45%) lesions, but also had raised (25%) or irregular borders (33%), which were not commonly observed in the reviewer-classified EM or tick bite reaction lesions. Participants with lesions classified as EM reported that they had the lesions for more days (p = 0.043) and reported more symptoms (p = 0.017) than participants with other lesions. Only 14 (20%) participants overall had positive laboratory evidence for LD; these included 13 (37%) of the participants with EM-classified lesions. Conclusions EM commonly occurs in forms that are not the classic bull's eye. Patients often present with lesions that may represent the very early stage of EM or tick bite reactions, and most patients will test negative on currently available laboratory tests, challenging clinicians in making an LD diagnosis or treatment decisions. Additional studies to further characterize the morphological features of EM and how variation in skin lesions may be perceived among clinicians would be helpful for developing guidelines on improving clinician recognition of EM.

5.
Cancers (Basel) ; 13(5)2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33800889

RESUMEN

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin cancer. Most MCC tumors contain integrated Merkel cell polyomavirus DNA (virus-positive MCC, VP-MCC) and carry a low somatic mutation burden whereas virus-negative MCC (VN-MCC) possess numerous ultraviolet-signature mutations. In contrast to viral oncogenes and sequence mutations, little is known about genomic structural variants in MCC. To identify copy number variants in commonly altered genes, we analyzed genomic DNA from 31 tumor samples using the Nanostring nCounter copy number cancer panel. Unsupervised clustering revealed three tumor groups with distinct genomic structural variant signatures. The first cluster was characterized by multiple recurrent deletions in genes such as RB1 and WT1. The second cluster contained eight VP-MCC and displayed very few structural variations. The final cluster contained one VP-MCC and four VN-MCC with predominantly genomic amplifications in genes like MDM4, SKP2, and KIT and deletions in TP53. Overall, VN-MCC contained more structure variation than VP-MCC but did not cluster separately from VP-MCC. The observation that most MCC tumors demonstrate a deletion-dominated structural group signature, independent of virus status, suggests a shared pathophysiology among most VP-MCC and VN-MCC tumors.

6.
Int J Dermatol ; 58(10): 1160-1164, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30790276

RESUMEN

BACKGROUND: Bardet-Biedl syndrome (BBS) is a rare, pleiotropic syndrome and member of a diverse group of disorders known as ciliopathies. Improved understanding of dermatoses in BBS will further understanding of the syndrome and will help define the role of dermatologists in providing care for patients with BBS. The purpose of this study was to describe the cutaneous phenotype of BBS in patients attending a large, multispecialty BBS clinic. METHODS: All patients attending the multispecialty BBS Clinic at the Marshfield Medical Center over a 12-month period were invited to participate. Complete cutaneous examinations were performed by a board-certified dermatologist, and comprehensive physical examinations were performed by clinic physicians. Molecular genetic results were obtained when available. Comprehensive laboratory studies were performed in each patient including fasting blood sugar and thyroid and renal function. RESULTS: Thirty-one individuals ranging in age between 2 and 69 years (median age, 12 years) participated in the study. Cutaneous findings were present in all subjects. Keratosis pilaris was present in 80.6% of subjects, and seborrheic dermatitis was present in 19.3%. Obesity, a cardinal feature of BBS, was present in the majority of subjects (90.3%) and was accompanied by known obesity-related dermatologic disorders. CONCLUSIONS: Cutaneous disorders are common in BBS and suggest disturbance of keratinization and keratinocyte function as well as systemic consequences of BBS on skin health. Increased prevalence of skin barrier dysfunction in this ciliopathy demonstrates the importance of dermatologist contribution to health care in BBS.


Asunto(s)
Anomalías Múltiples/epidemiología , Síndrome de Bardet-Biedl/complicaciones , Enfermedad de Darier/epidemiología , Dermatitis Seborreica/epidemiología , Cejas/anomalías , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Adolescente , Adulto , Anciano , Síndrome de Bardet-Biedl/genética , Niño , Preescolar , Enfermedad de Darier/diagnóstico , Enfermedad de Darier/genética , Dermatitis Seborreica/diagnóstico , Dermatitis Seborreica/genética , Femenino , Pruebas Genéticas , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Prevalencia , Estudios Prospectivos , Wisconsin/epidemiología , Adulto Joven
7.
JAMA Dermatol ; 153(10): 977-982, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-28832872

RESUMEN

IMPORTANCE: The long-term implications of hepatotoxic effects in patients with psoriasis remains uncharacterized, and a method is needed for the noninvasive monitoring of the development and progression of hepatic fibrosis in patients with psoriasis receiving long-term methotrexate therapy. OBJECTIVE: To evaluate if NASH FibroSure, a noninvasive test for nonalcoholic steatohepatitis (NASH) and hepatic fibrosis, can be used for patients with psoriasis to aid in determining eligibility for methotrexate sodium (MTX) therapy, monitor for the development of MTX-induced hepatotoxic effects, and monitor for worsening of hepatic fibrosis scores during MTX therapy. DESIGN, SETTING, AND PARTICIPANTS: A retrospective descriptive analysis was conducted among a cohort of patients with psoriasis treated with MTX who underwent NASH FibroSure testing between January 1, 2007, and December 31, 2013, at a dermatology referral center at a single institution. Data analysis was performed from January 1 to December 31, 2014. MAIN OUTCOMES AND MEASURES: NASH FibroSure risk scores suggesting the development and progression of hepatic fibrosis in patients with psoriasis receiving long-term MTX therapy. RESULTS: Included in the institutional experience portion of the study were 129 patients with psoriasis undergoing treatment with MTX, while 107 patients (57 women and 50 men; mean [SD] age, 83.3 [13.5] years) underwent NASH FibroSure testing during MTX therapy and were eligible for correlation analysis. Of the 129 patients with psoriasis undergoing treatment with MTX, 69 (53.5%) underwent NASH FibroSure testing prior to starting MTX; 19 of those patients (27.5%) had elevated fibrosis scores, and 54 (78.3%) had elevated steatosis scores. Among the 107 patients who underwent NASH FibroSure testing during MTX therapy, the cumulative MTX dose corresponded to a statistically significant association of a higher NASH FibroSure hepatic fibrosis score in women (Spearman ρ = 0.21; P = .02) but not in men (Spearman ρ = 0.17; P = .11). All patients in the cohort except 1 were managed without a liver biopsy. CONCLUSIONS AND RELEVANCE: The patients with psoriasis in this study had a high prevalence of elevated hepatic steatosis scores. The NASH FibroSure test can be used to monitor changes in fibrosis score in patients with psoriasis receiving MTX. In a single-institution cohort, these results suggest that NASH FibroSure may be used, especially among female patients, to help monitor for risk of worsening fibrosis during MTX therapy.

9.
Med Mycol ; 46(1): 1-15, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17852717

RESUMEN

The agglutinin-like sequence (ALS) family of Candida albicans includes eight genes that encode large cell-surface glycoproteins. The high degree of sequence relatedness between the ALS genes and the tremendous allelic variability often present in the same C. albicans strain complicated definition and characterization of the gene family. The main hypothesis driving ALS family research is that the genes encode adhesins, primarily involved in host-pathogen interactions. Although adhesive function has been demonstrated for several Als proteins, the challenge of studying putative adhesins in a highly adhesive organism like C. albicans has led to varying ideas about how best to pursue such investigations, and results that are sometimes contradictory. Recent analysis of alsdelta/alsdelta strains suggested roles for Als proteins outside of adhesion to host surfaces, and a broader scope of Als protein function than commonly believed. The availability and use of experimental methodologies to study C. albicans at the genomic level, and the ALS family en masse, have advanced knowledge of these genes and emphasized their importance in C. albicans biology and pathogenesis.


Asunto(s)
Adhesinas Bacterianas/genética , Candida albicans/genética , Candida albicans/patogenicidad , Proteínas Fúngicas/genética , Familia de Multigenes , Adhesinas Bacterianas/química , Adhesinas Bacterianas/metabolismo , Aglutininas/genética , Aglutininas/metabolismo , Alelos , Adhesión Bacteriana , Candida/genética , Candida/metabolismo , Candida albicans/metabolismo , Candidiasis/microbiología , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Genoma Fúngico , Humanos
11.
Microbiology (Reading) ; 152(Pt 8): 2287-2299, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16849795

RESUMEN

Candida albicans ALS3 encodes a large cell-surface glycoprotein that has adhesive properties. Immunostaining of cultured C. albicans germ tubes showed that Als3p is distributed diffusely across the germ tube surface. Two-photon laser scanning microscopy of model catheter biofilms grown using a PALS3-green fluorescent protein (GFP) reporter strain showed GFP production in hyphae throughout the biofilm structure while biofilms grown using a PTPI1-GFP reporter strain showed GFP in both hyphae and yeast-form cells. Model catheter biofilms formed by an als3 Delta/als3 Delta strain were weakened structurally and had approximately half the biomass of a wild-type biofilm. Reintegration of a wild-type ALS3 allele restored biofilm mass and wild-type biofilm structure. Production of an Als3p-Ag alpha 1p fusion protein under control of the ALS3 promoter in the als3 Delta/als3 Delta strain restored some of the wild-type biofilm structural features, but not the wild-type biofilm mass. Despite its inability to restore wild-type biofilm mass, the Als3p-Ag alpha 1p fusion protein mediated adhesion of the als3 Delta/als3 Delta C. albicans strain to human buccal epithelial cells (BECs). The adhesive role of the Als3p N-terminal domain was further demonstrated by blocking adhesion of C. albicans to BECs with immunoglobulin reactive against the Als3p N-terminal sequences. Together, these data suggest that portions of Als3p that are important for biofilm formation may be different from those that are important in BEC adhesion, and that Als3p may have multiple functions in biofilm formation. Overexpression of ALS3 in an efg1 Delta/efg1 Delta strain that was deficient for filamentous growth and biofilm formation resulted in growth of elongated C. albicans cells, even under culture conditions that do not favour filamentation. In the catheter biofilm model, the ALS3 overexpression strain formed biofilm with a mass similar to that of a wild-type control. However, C. albicans cells in the biofilm had yeast-like morphology. This result uncouples the effect of cellular morphology from biofilm formation and underscores the importance of Als3p in biofilm development on silicone elastomer surfaces.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Candida albicans/fisiología , Proteínas Fúngicas/fisiología , Cateterismo , Contaminación de Equipos , Proteínas Fúngicas/química , Humanos , Elastómeros de Silicona
12.
Med Mycol ; 44(2): 103-11, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16519012

RESUMEN

ALS gene expression was studied in the hyposalivatory rat model of oral candidiasis and in clinical specimens collected from HIV-positive patients to assess similarities in expression patterns between the model system and clinical isolates. Two Candida albicans strains, SC5314 and OY-2-76, were used in the rat model system and infection progressed for 3 or 5 days. The strains produced similar oral lesions at 3 days. At 5 days, strain OY-2-76 produced more superficial lesions containing relatively more yeast forms compared to invasive hyphal forms observed for strain SC5314. For all infections, the most severe lesions were observed on the tongue and gingiva overlying the mandible. ALS transcripts were easier to detect by RT-PCR later in infection and under other conditions where more fungal cells were present. Expression of ALS1, ALS2, ALS3 and ALS4 was observed in rats infected for 3 days with ALS5 and ALS9 transcripts detected after 5 days of infection. Expression of ALS6 was observed in a single specimen from a 5-day infection while ALS7 transcript was never found. Expression of all ALS genes was observed in oral clinical material collected from HIV-positive patients although ALS6 and ALS7 transcripts required an extra PCR amplification step to be detected. Overall, the patterns of ALS gene expression were similar between the rat model and human clinical specimens, suggesting that the model would be useful for studying the phenotype of al delta/al delta mutant strains.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Candida albicans/genética , Candidiasis Bucal/microbiología , Proteínas Fúngicas/genética , Infecciones por VIH/microbiología , Xerostomía/microbiología , Infecciones Oportunistas Relacionadas con el SIDA/patología , Adulto , Animales , Candida albicans/metabolismo , Candidiasis Bucal/patología , Candidiasis Bucal/virología , Modelos Animales de Enfermedad , Femenino , Proteínas Fúngicas/biosíntesis , Regulación Fúngica de la Expresión Génica , VIH/crecimiento & desarrollo , Infecciones por VIH/virología , Histocitoquímica , Humanos , Masculino , Mucosa Bucal/microbiología , ARN/química , ARN/genética , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
Infect Immun ; 73(3): 1852-5, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15731087

RESUMEN

Candida albicans PALS-green fluorescent protein (GFP) reporter strains were inoculated into mice in a disseminated candidiasis model, and GFP production was monitored by immunohistochemistry and reverse transcription-PCR (RT-PCR). GFP production from the ALS1 and ALS3 promoters was detected immunohistochemically. ALS1, ALS2, ALS3, ALS4, and ALS9 transcription was detected by RT-PCR, further identifying ALS genes expressed in this model.


Asunto(s)
Aglutininas/genética , Candida albicans/patogenicidad , Candidiasis/microbiología , Proteínas Fúngicas/genética , Fungemia/microbiología , Expresión Génica , Aglutininas/metabolismo , Animales , Candida albicans/genética , Candida albicans/metabolismo , Modelos Animales de Enfermedad , Femenino , Proteínas Fúngicas/metabolismo , Genes Fúngicos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
14.
Microbiology (Reading) ; 151(Pt 4): 1051-1060, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15817774

RESUMEN

The gene encoding yeast-enhanced green fluorescent protein (GFP) was placed under control of ALS gene promoters in Candida albicans. The PALS-GFP reporter strains were validated using various techniques including a new real-time RT-PCR assay to quantify ALS gene expression. The PALS-GFP reporter strains were grown in media that promoted yeast or germ tube forms, and the resulting fluorescence was measured by flow cytometry. In addition to results that indicate differences in ALS gene expression due to growth medium, growth stage and developmental programme, new data show large differences in transcriptional level among the ALS genes. Expression of ALS1 was associated with transfer of the PALS1-GFP strain to fresh growth medium. ALS3 expression increased markedly when germ tubes were visible microscopically and ALS7 expression exhibited a transient peak between 2 and 3 h following inoculation into fresh YPD medium. Transcription from the ALS1 and ALS3 promoters was strongest among those tested and contrasted markedly with the weaker promoter strength at the ALS5, ALS6, ALS7 and ALS9 loci. These weaker transcriptional responses were also observed using real-time RT-PCR measurements on wild-type C. albicans cells. Assuming a positive correlation between transcriptional level and protein production, these results suggest that some Als proteins are abundant on the C. albicans cell surface while others are produced at a much lower level.


Asunto(s)
Candida albicans/genética , Genes Fúngicos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Secuencia de Bases , Candida albicans/crecimiento & desarrollo , Cartilla de ADN/genética , ADN de Hongos/genética , Citometría de Flujo , Proteínas Fúngicas/genética , Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Regiones Promotoras Genéticas , Proteínas Recombinantes de Fusión/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas
15.
Microbiology (Reading) ; 150(Pt 2): 267-275, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14766904

RESUMEN

An RT-PCR assay was developed to analyse expression patterns of genes in the Candida albicans ALS (agglutinin-like sequence) family. Inoculation of a reconstituted human buccal epithelium (RHE) model of mucocutaneous candidiasis with strain SC5314 showed destruction of the epithelial layer by C. albicans and also formation of an upper fungal layer that had characteristics similar to a biofilm. RT-PCR analysis of total RNA samples extracted from C. albicans-inoculated buccal RHE showed that ALS1, ALS2, ALS3, ALS4, ALS5 and ALS9 were consistently detected over time as destruction of the RHE progressed. Detection of transcripts from ALS7, and particularly from ALS6, was more sporadic, but not associated with a strictly temporal pattern. The expression pattern of ALS genes in C. albicans cultures used to inoculate the RHE was similar to that observed in the RHE model, suggesting that contact of C. albicans with buccal RHE does little to alter ALS gene expression. RT-PCR analysis of RNA samples extracted from model denture and catheter biofilms showed similar gene expression patterns to the buccal RHE specimens. Results from the RT-PCR analysis of biofilm RNA specimens were consistent between various C. albicans strains during biofilm development and were comparable to gene expression patterns in planktonic cells. The RT-PCR assay described here will be useful for analysis of human clinical specimens and samples from other disease models. The method will provide further insight into the role of ALS genes and their encoded proteins in the diverse interactions between C. albicans and its host.


Asunto(s)
Aglutininas/genética , Candida albicans/genética , Candidiasis Bucal/diagnóstico , Células Epiteliales/microbiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Secuencia de Bases , Biopelículas , Cartilla de ADN , Proteínas Fúngicas/genética , Humanos , Sensibilidad y Especificidad
16.
Microbiology (Reading) ; 150(Pt 7): 2415-2428, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15256583

RESUMEN

The ALS (agglutinin-like sequence) gene family of Candida albicans encodes eight cell-surface glycoproteins, some of which are involved in adherence to host surfaces. A mutational analysis of each ALS gene is currently being performed to deduce the functions of the encoded proteins and to better understand the role of these proteins in C. albicans biology and pathogenesis. This paper describes construction of an als3/als3 mutant and comparison of its phenotype to an als1/als1 strain. Efforts to disrupt ALS3 indicated that the gene could be deleted in two transformation steps, suggesting that the gene is encoded by a single locus and that the ALS3-like locus, ALS8, does not exist. Strains lacking ALS3 or ALS1 did not exhibit a defect in germ tube formation when grown in RPMI 1640 medium, but the als1/als1 mutant formed significantly fewer germ tubes in Lee medium. Analysis of ALS3 and ALS1 promoter activity using green fluorescent protein (GFP) reporter strains and flow cytometry showed that when cells are placed into medium that promotes germ tube formation, ALS1 is transcribed prior to ALS3. Comparison of the mutant strains in adhesion assays showed that the als3/als3 strain was defective in adhesion to both human umbilical vein endothelial cells (HUVEC) and buccal epithelial cells (BEC), but not to fibronectin-coated plastic plates. In contrast, the als1/als1 strain showed decreased adherence to HUVEC, but adherence to BEC and fibronectin were the same as wild-type controls. Inoculation of the buccal reconstituted human epithelium (RHE) model of oral candidiasis with the mutant strains showed nearly a total lack of adhesion and epithelial destruction by the als3/als3 mutant while the als1/als1 strain showed only a slightly reduced degree of epithelial destruction compared to the wild-type control. Adhesion data presented here suggest that, in the assays performed, loss of Als3p affects C. albicans adhesion more than loss of Als1p. Collectively, these results demonstrate functional similarities and differences between Als1p and Als3p, and suggest the potential for more complex interrelationships between the ALS genes and their encoded proteins.


Asunto(s)
Candida albicans/fisiología , Candida albicans/patogenicidad , Células Epiteliales/microbiología , Proteínas Fúngicas/metabolismo , Candida albicans/genética , Candidiasis Bucal/microbiología , Adhesión Celular , Línea Celular , Células Cultivadas , Clonación Molecular , Proteínas Fúngicas/genética , Eliminación de Gen , Humanos , Datos de Secuencia Molecular , Mucosa Bucal/citología , Mucosa Bucal/microbiología , Análisis de Secuencia de ADN
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