Browsing by Author "Yang, Yun-Liang"

Now showing 1 - 20 of 31

A method of layer-by-layer gold nanoparticle hybridization in a quartz crystal microbalance DNA sensing system used to detect dengue virus
(2009-05-27)
Chen, Sz-Hau
;
Chuang, Yao-Chen
;
Lu, Yi-Chen
;
Lin, Hsiu-Chao
;
Yang, Yun-Liang
Dengue virus (DENV) is nowadays the most important arthropod-spread virus affecting humans existing in more than 100 countries worldwide. A rapid and sensitive detection method for the early diagnosis of infectious dengue virus urgently needs to be developed. In the present study, a circulating-flow quartz crystal microbalance (QCM) biosensing method combining oligonucleotide-functionalized gold nanoparticles (i.e. AuNP probes) used to detect DENV has been established. In the DNA-QCM method, two kinds of specific AuNP probes were linked by the target sequences onto the QCM chip to amplify the detection signal, i.e. oscillatory frequency change (Delta F) of the QCM sensor. The target sequences amplified from the DENV genome act as a bridge for the layer-by-layer AuNP probes' hybridization in the method. Besides being amplifiers of the detection signal, the specific AuNP probes used in the DNA-QCM method also play the role of verifiers to specifically recognize their target sequences in the detection. The effect of four AuNP sizes on the layer-by-layer hybridization has been evaluated and it is found that 13 nm AuNPs collocated with 13 nm AuNPs showed the best hybridization efficiency. According to the nanoparticle application, the DNA-QCM biosensing method was able to detect dengue viral RNA in virus-contaminated serum as plaque titers being 2 PFU ml(-1) and a linear correlation (R(2) = 0.987) of Delta F versus virus titration from 2 x 10(0) to 2 x 10(6) PFU ml(-1) was found. The sensitivity and specificity of the present DNA-QCM method with nanoparticle technology showed it to be comparable to the fluorescent real-time PCR methods. Moreover, the method described herein was shown to not require expensive equipment, was label-free and highly sensitive.
An emerging issue of mixed yeast cultures
(2014-08-01)
Yang, Yun-Liang
;
Chu, Wen-Li
;
Lin, Chih-Chao
;
Tsai, Sheng-Hua
;
Chang, Te-Pin
Background: Different yeast species have different susceptibilities to commonly prescribed antifungal drugs. Thus, it is important to accurately determine the species of pathogenic yeasts, especially when more than one species are in a specimen. Methods: Clinically significant yeast isolates were collected via the Taiwan Surveillance of Antimicrobial Resistance of Yeasts from July to September in 2010. The identifications of isolates were assessed in the core laboratory at the National Health Research Institutes. Results: Of the 1127 isolates recovered, 1088 were of Candida genus, accounting for 96.53% of the total isolates, followed by Cryptococcus (15, 1.33%), Trichosporon (12, 1.06%), Kodamaea (4, 0.35%), Pichia (4, 0.35%), and three others. In all, 38 out of 1116 (3.4%) specimens had mixed yeast cultures. One ascites specimen had three species, Candida albicans, Candida glabrata, and Candida tropicalis. In the remaining 37 specimens, 16 had a combination of C. albicans and C. glabrata, eight C. albicans and C. tropicalis, five C. glabrata and C. tropicalis, three Candida krusei and C. tropicalis, and five with different combinations. Conclusion: The high prevalence of cultures with mixed yeasts may be an emerging issue. Thus, to determine mixed yeast cultures in the same specimen, we highly recommend CHROMagar Candida medium to culture yeast isolates directly from the specimen. Copyright (C) 2013, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.
Association between fluconazole susceptibility and genetic relatedness among Candida tropicalis isolates in Taiwan
(2007-05-01)
Wang, Jang-Shiun
;
Li, Shu-Ying
;
Yang, Yun-Liang
;
Chou, Hsiao-Hui
;
Lo, Hsiu-Jung
Among the 162 Candida tropicalis isolates Collected in the Taiwan Surveillance of Antimicrobial Resistance of Yeasts in 1999, 23 (14.2%) had fluconazole MICs >= 64 mg l(-1), and thus fulfilled the definition of resistance. Random amplified polymorphic DNA assay showed that all 23 fluconazole-resistance C. tropicalis isolates collected from different hospitals around Taiwan were closely related. Two distinct pulsotypes associated with fluconazole susceptibility were identified when these 23 resistant isolates, along with 13 susceptible ones, were analysed by PFGE.
Automatic method to compare the lanes in gel electrophoresis images
(2007-03-01)
Lin, Chih-Yang
;
Ching, Yu-Tai
;
Yang, Yun-Liang
;
生物科技學系
;
資訊工程學系
Gel electrophoresis (GE) is an important tool in genomic analysis. GE results are presented using images. Each image contains several vertical lanes. Each lane consists of several horizontal bands. Two lanes are identical if the relative positions of the bands are the same. We present a computer method designed to compare the lanes and identify identical lanes. This method, developed using many image-processing techniques, is applied to segment the lanes and bands in GE images. The lanes are then converted into "position vectors" that describe the positions of the bands. Comparing lanes becomes equivalent to comparing the position vectors. This method can accurately identify identical lanes, helping biologists to identify the identical lanes from many lanes with much less effort.
Candida albicans ENO1 null mutants exhibit altered drug susceptibility, hyphal formation, and virulence
(2013-06-01)
Ko, Hui-Ching
;
Hsiao, Ting-Yin
;
Chen, Chiung-Tong
;
Yang, Yun-Liang
;
生物科技學系
We previously showed that the expression of ENO1 (enolase) in the fungal pathogen Candida albicans is critical for cell growth. In this study, we investigate the contribution of the ENO1 gene to virulence. We conducted our functional study of ENO1 in C. albicans by constructing an eno1/eno1 null mutant strain in which both ENO1 alleles in the genome were knockouted with the SAT1 flipper cassette that contains the nourseothricin-resistance marker. Although the null mutant failed to grow on synthetic media containing glucose, it was capable of growth on media containing yeast extract, peptone, and non-fermentable carbon sources. The null mutant was more susceptible to certain antifungal drugs. It also exhibited defective hyphal formation, and was avirulent in BALB/c mice.
Characterization of Candida Species from Different Populations in Taiwan
(2011-08-01)
Yang, Yun-Liang
;
Hsieh, Li-Yun
;
Wang, An-Huei
;
Lo, Hsiu-Jung
;
生物科技學系
The opportunistic Candida species existing as part of commensal microbiota in humans are usually the etiological agents causing infections. We investigated whether isolates collected from different age groups, hospital units, and sources have distinct characteristics. A total of 913 isolates comprising 395 Candida albicans, 230 Candida tropicalis, 202 Candida glabrata, 62 Candida parapsilosis, 13 Candida krusei, and 11 of other six species were analyzed. Urine was the most common source (41.2%), followed by sputum (16.3%), blood (15.2%), and others (27.3%). Candida albicans and C. parapsilosis were more prevalent in the working group [from 19 to 65 years], whereas C. tropicalis and C. glabrata were more prevalent in the elder one (a parts per thousand yen 66 years). We found that the age of patients and the source of isolates affect the distribution of species. On the other hand, the drug susceptibility of isolates was associated with fungal species and whether patients were hospitalized.
Combinatorial Computational Approaches to Identify Tetracycline Derivatives as Flavivirus Inhibitors
(2007-05-09)
Yang, Jinn-Moon
;
Chen, Yan-Fu
;
Tu, Yu-Yin
;
Yen, Kuei-Rong
;
Yang, Yun-Liang
Limited structural information of drug targets, cellular toxicity possessed by lead compounds, and large amounts of potential leads are the major issues facing the design-oriented approach of discovering new leads. In an attempt to tackle these issues, we have developed a process of virtual screening based on the observation that conformational rearrangements of the dengue virus envelope protein are essential for the mediation of viral entry into host cells via membrane fusion. Screening was based solely on the structural information of the Dengue virus envelope protein and was focused on a target site that is presumably important for the conformational rearrangements necessary for viral entry. To circumvent the issue of lead compound toxicity, we performed screening based on molecular docking using structural databases of medical compounds. To enhance the identification of hits, we further categorized and selected candidates according to their novel structural characteristics. Finally, the selected candidates were subjected to a biological validation assay to assess inhibition of Dengue virus propagation in mammalian host cells using a plaque formation assay. Among the 10 compounds examined, rolitetracycline and doxycycline significantly inhibited plaque formation, demonstrating their inhibitory effect on dengue virus propagation. Both compounds were tetracycline derivatives with IC(50)s estimated to be 67.1 mu M and 55.6 mu M, respectively. Their docked conformations displayed common hydrophobic interactions with critical residues that affected membrane fusion during viral entry. These interactions will therefore position the tetracyclic ring moieties of both inhibitors to bind firmly to the target and, subsequently, disrupt conformational rearrangement and block viral entry. This process can be applied to other drug targets in which conformational rearrangement is critical to function.
Comparison of Human and Soil Candida tropicalis Isolates with Reduced Susceptibility to Fluconazole
(2012-04-05)
Yang, Yun-Liang
;
Lin, Chih-Chao
;
Chang, Te-Pin
;
Lauderdale, Tsai-Ling
;
Chen, Hui-Ting
Infections caused by treatment-resistant non-albicans Candida species, such as C. tropicalis, has increased, which is an emerging challenge in the management of fungal infections. Genetically related diploid sequence type (DST) strains of C. tropicalis exhibiting reduced susceptibility to fluconazole circulated widely in Taiwan. To identify the potential source of these wildly distributed DST strains, we investigated the possibility of the presence in soil of such C. tropicalis strains by pulsed field gel electrophoresis (PFGE) and DST typing methods. A total of 56 C. tropicalis isolates were recovered from 26 out of 477 soil samples. Among the 18 isolates with reduced susceptibility to fluconazole, 9 belonged to DST149 and 3 belonged to DST140. Both DSTs have been recovered from our previous studies on clinical isolates from the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) program. Furthermore, these isolates were more resistant to agricultural azoles. We have found genetically related C. tropicalis exhibiting reduced susceptibility to fluconazole from the human hosts and environmental samples. Therefore, to prevent patients from acquiring C. tropicalis with reduced susceptibility to azoles, prudent use of azoles in both clinical and agricultural settings is advocated.
Cph1p negatively regulates MDR1 involved in drug resistance in Candida albicans
(2015-06-01)
Lo, Hsiu Jung
;
Tseng, Kuo-Yun
;
Kao, Yeong-Yi
;
Tsao, Ming-Yang
;
Lo, Han-Lun
The cph1/cph1 efg1/efg1 double mutant in Candida albicans is defective in filamentous growth and is avirulent in a mouse model. We previously reported that Efg1p but not Cph1p is involved in drug resistance by negatively regulating ERG3 in C. albicans. In the current study, we have found that overexpression of 0411 in Saccharomyces cerevisiae increases susceptibility to the antifungal drug fluconazole. Furthermore, in C. albicans, null mutation of 0411 increased the expression of MDR1 as well as decreased susceptibility to fluconazole and voriconazole but not to amphotericin B. These findings indicate that although Efg1p and Cph1p may have the same effects on virulence, they have opposite effects on drug resistance in C. albicans. (C) 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Distribution and antifungal susceptibility of Candida species isolated from different age populations in Taiwan
(2006-05-01)
Yang, Yun-Liang
;
Cheng, Hsiao-Hsu
;
Lo, Hsiu-Jung
;
生物科技學系
;
Department of Biological Science and Technology
A total of 3926 yeast isolates were isolated from 24 hospitals participating in the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) from July to September 2002. Candida albicans (69.1%) was the most common species, followed by Candida tropicalis (12.9%), Candida glabrata (8.3%), Candida parapsilosis (2.7%), Candida krusei (0.6%), and others (6.4%). To study the distribution and antifungal susceptibility of Candida species according to sources and patient ages, we have collected and analyzed the clinical data of 861 isolates. Of those 861 isolates, urine was the most common source (40%) followed by sputum (22.1%), blood (13.5%), central venous catheter (5.5%), wound (5.2%), and others (13.7%). With increasing age, we observed a significant increase in the percentage of isolates from urine (P = 0.00005) and a parallel reduction from blood (P = 0.009). As expected, more elder patients were hospitalized than younger ones (P = 0.05). In total, 2.7% and 1.9% of isolates were resistant to amphotericin B and fluconazole, respectively. Antifungal susceptibilities of isolates from different age groups were not significantly different.
Distribution and drug susceptibilities of Candida species causing candidemia from a medical center in central Taiwan
(2013-12-01)
Chang, Te-Pin
;
Ho, Mao-Wang
;
Yang, Yun-Liang
;
Lo, Pai-Chang
;
Lin, Pei-Sheng
Invasive fungal infections have increased significantly in the past few decades because of the increase in high-risk populations. To investigate the distribution and drug susceptibilities of such infections, we analyzed all 152 Candida isolates causing candidemia from 2004 to 2006 at the China Medical University Hospital, a medical center in central Taiwan. Candida albicans was the most common species, accounting for 52.6 % of the isolates, followed by C. tropicalis (19.7 %), C. parapsilosis (14.5 %), C. glabrata (8.6 %), C. guilliermondii (3.9 %), and C. pelliculosa (0.7 %). All isolates were susceptible to amphotericin B, anidulafungin, micafungin, and voriconazole according to minimum inhibitory concentrations (MICs) after a 24-h incubation; 0.7 %, 6.6 %, and 7.9 % of isolates were resistant to amphotericin B, fluconazole, and voriconazole, respectively, after 48-h incubation. Both C. albicans and C. parapsilosis had high degrees of agreement for azoles between 24- and 48-h incubation periods, whereas C. glabrata (38.5-46.2 %) and C. tropicalis (56.7-63.3 %) did not. The majority of the isolates with high azole MICs displayed a trailing growth phenotype. Hence, the MICs of different drugs after 24-h incubation may be considered for prognosis of candidemia.
Fruits as the vehicle of drug resistant pathogenic yeasts
(2017-09-01)
Lo, Hsiu-Jung
;
Tsai, Sheng-Hua
;
Chu, Wen-Li
;
Chen, Yin-Zhi
;
Zhou, Zi-Li
Objective: We investigated the diversity and drug susceptibility of pathogenic yeasts on fruit surfaces. Method: Fruits were purchased from supermarkets and washed with buffer. The pellets were re-suspended in medium after centrifugation. The cell suspensions were plated onto CHROMagar Candida medium. Yeasts were identified by ribosomal DNA sequencing and their drug susceptibilities were determined by broth microdilution assay. Results: Of 184 isolates, comprised of 55 species, from 22 different types of fruits, 29 species, including Candida famata, Candida fermentati, Candida guilliermondii, Candida intermedia, Candida krusei, Candida orthopsilosis, Candida parapsilosis, Candida pelliculosa, Candida tropicalis, and others have been reported to cause diseases in humans. In addition to C. krusei, intrinsically resistant to fluconazole, all Rhodotorula and Rhodosporidium species were resistant to fluconazole. One each of C. tropicalis isolate was belonged to diploid sequence type (DST)149 and DST225, genotypes also detected in isolates from humans. Furthermore, the DST225 isolate was less susceptible to azole drugs. The susceptibilities to azole drugs for clinical and agricultural usage were associated to each other. Conclusion: It is important to be aware of the existence of pathogenic yeasts, especially drug-resistant ones, on the fruit surfaces, a potential route for pathogenic yeasts to be transmitted to humans. (C) 2017 Published by Elsevier Ltd on behalf of The British Infection Association.
Genotype analysis based on intergenic spacer 1 sequences of Trichosporon asahii collected in Taiwan
(2013-11-01)
Yang, Yun-Liang
;
Liu, Yi-Wen
;
Chen, Hui-Ting
;
Tsai, Moan-Shane
;
Chu, Wen-Li
Among 32 Trichosporon asahii isolates collected in four rounds of the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) studies, conducted in 1999, 2002, 2006, and 2010, five different intergenic spacer 1 (IGS1) genotypes were detected. Genotype 1 was the most common (43.8%), followed by genotypes 3 (28.1%), 7 (12.5%), 5 (9.4%), and 4 (6.3%). Interestingly, genotype 7 was more prevalent in Taiwan than in other areas (P = 0.01); while we did not find a significant association between IGS1 genotype and susceptibility to antifungal drugs, we did note that the majority of isolates of T. asahii were susceptible to both fluconazole and voriconazole, consistent with previous reports. A higher proportion of isolates (P = 0.05) collected in 2010 (4/12, 33.3%) had high amphotericin B MICs (>= 2 mg/l) than those collected in the previous three TSARYs (1/21, 5%). Hence, the new data of genotypes and drug susceptibilities in the present study may contribute to the epidemiology of T. asahii
Loss of Heterozygosity of FCY2 Leading to the Development of Flucytosine Resistance in Candida tropicalis
(2011-06-01)
Chen, Yen-Ning
;
Lo, Hsiu-Jung
;
Wu, Chia-Chen
;
Ko, Hui-Ching
;
Chang, Te-Pin
As fluconazole resistance becomes an emerging issue for treating infections caused by Candida tropicalis, searching for alternative becomes a prominent task. In the present study, 97 clinical isolates of C. tropicalis were tested for the susceptibilities to flucytosine (5FC) with the Etest method. Although only one isolate was resistant to 5FC, 30 susceptible isolates could produce resistant progeny after exposure to the drug. Interestingly, 22 of these 30 clinical isolates had a heterozygous G/T at the 145th position on FCY2, encoding purine-cytosine permease, whereas their progeny recovered from within the inhibitory ellipses had homozygous T/T, resulting in null alleles for both copies of the gene and produced only truncated proteins, effecting the 5FC resistance. Furthermore, we found that two major fluconazole-resistant clinical clones, diploid sequence type 98 (DST98) and DST140, had a homozygous G/G at the 145th position, and neither was able to produce 5FC-resistant progeny within the inhibitory ellipses. Hence, strains of C. tropicalis containing heterozygous alleles may develop 5FC resistance readily, whereas those with homozygous G/G wild-type alleles can be treated with 5FC. Subsequently, a combination of 5FC and another antifungal drug is applicable for treating infections of C. tropicalis.
Mixed yeast infections in Taiwan
(2018-08-01)
Yang, Yun-Liang
;
Chu, Wen-Li
;
Lin, Chih-Chao
;
Zhou, Zi-Li
;
Chen, Pei-Ning
Clinically significant yeast isolates were collected via Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) in 2014, and mixed infections were investigated. Among 44 out of 1092 specimens containing multiple species, 17, 11, 5, 3, and 8 were from urine, sputum, blood, ascites, and 6 others, respectively. There predominant combinations of mixed infection were 14 Candida albicans/Candida glabrata, 13 C. albicans/Candida tropicalis, and 9 C. glabrata/C. tropicalis. Furthermore, we also detected fluconazole resistant isolates Candida norvegensis and Candida krusei. Hence, it is important to accurately identify the species with different drug susceptibilities when they are in the same specimen.
Ndt80p is involved in L-sorbose utilization through regulating SOU1 in Candida albicans
(2015-01-01)
Lo, Hsiu-Jung
;
Chu, Wen-Li
;
Liou, Ci-Hong
;
Huang, Szu-Hsuan
;
Khoo, Kay-Hooi
Ndt80p, a known transcriptional factor, regulates various targets involved in stress responses, filamentous growth, and virulence in Candida albicans. Potential targets of Ndt80p have been identified at the transcriptional level. The present study was conducted to identify genes regulated by Ndt80p from the protein level. We found that the levels of Ahp1p, Fma1p, Hsp21p, Rfa2p, Snz1p, Sod1p, Soul p, Trp99p, orf19.251, orf19.1862, and orf19.5620, were affected by the null mutation of NDT80 by two-dimensional polyacrylamide gel-electrophoresis analysis. Among the 11 proteins, all but Sou1p and Rfa2p are suggested to be involved in known functions of Ndt80p. Here, we demonstrate that Ndt80p plays a role in t-sorbose utilization through regulating SOU1 in C. albicans. (C) 2014 Elsevier GmbH. All rights reserved.
Non-lethal Candida albicans cph1/cph1 efg1/efg1 mutant partially protects mice from systemic infections by lethal wild-type cells
(2009-03-01)
Yang, Yun-Liang
;
Wang, Chih-Wei
;
Chen, Chiung-Tony
;
Wang, Min-Hsien
;
Hsiao, Chin-Fu
Although Candida albicans cph1/cph1 efg1/efg1 mutant cells are not lethal to mice, they proliferated in infected mice instead of simply being cleared by the host immune system. Here, we have shown that the cph1/cph1 efg1/efg1 mutant partially protects mice from systemic infections by the lethal wild-type Candida albicans cells. Our results further indicate that a second dose of the cph1/cph1 efg1/efg1 mutant did not boost the degree of protection. (c) 2008 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Oropharyngeal Colonization of HIV-Infected Outpatients in Taiwan by Yeast Pathogens
(2010-07-01)
Yang, Yun-Liang
;
Hung, Chien-Ching
;
Wang, An-Huei
;
Tseng, Fan-Chen
;
Leaw, Shiang Ning
Among 234 isolates comprising 26 different Candida species colonizing the oropharynx of 181 (54.3% of 399 surveyed) HIV-infected outpatients, 27 (11.7%) were fluconazole resistant. Antibacterial treatment was associated with increased rates of yeast colonization, while antiretroviral therapy and pneumococcal vaccination protected patients from yeast colonization.
Predisposing factors for oropharyngeal colonization of yeasts in human immunodeficiency virus-infected patients: A prospective cross-sectional study
(2013-04-01)
Lin, Jiun-Nong
;
Lin, Chih-Chao
;
Lai, Chung-Hsu
;
Yang, Yun-Liang
;
Chen, Hui-Ting
Background: Oropharyngeal candidiasis continues to be a major opportunistic infection in human immunodeficiency virus (HIV)-infected patients. The objectives of this study were to investigate the prevalence, associated factors, and microbiologic features for oropharyngeal yeast colonization in HIV-infected patients. Methods: From October to December 2009, consecutive HIV-infected patients older than 18 years were recruited in this study. Demographic information, underlying conditions, and clinical histories were collected. Oropharyngeal swab cultures for yeasts and antifungal drug susceptibilities of the isolates were performed. Results: Of the 105 HIV-infected patients, 54 (51.4%) were colonized with yeasts, including 11 patients (20.4%) with more than one species. Among the 68 isolates, Candida albicans accounted for 73.5%, followed by Candida tropicalis (5.9%), Candida glabrata (5.9%), and Candida dubliniensis (4.4%). There were 7.5% and 6% Candida isolates resistant to fluconazole and voriconazole, respectively. All of the Candida isolates were susceptible to amphotericin B. A higher prevalence of yeast colonization was noted in patients with a CD4 cell count <= 200 cells/mu L (p = 0.032). Multivariate regression analysis showed that intravenous drug use was an independent associated factor for oropharyngeal yeast colonization (odds ratio, 5.35; 95% confidence interval, 1.39-20.6; p = 0.015), as well as protease inhibitor-containing anti-retroviral therapy (odds ratio, 3.59; 95% confidence interval, 1.41-9.12; p = 0.007). Conclusion: Despite previous studies showing that protease inhibitors decreased Candida adhesion to epithelial cells in vitro, the current study found protease inhibitor-containing anti-retroviral therapy predisposed to oropharyngeal yeast colonization in HIV-infected patients. Copyright (C) 2012, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. All rights reserved.
Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus colonization among human immunodeficient virus-infected outpatients in Taiwan: oral Candida colonization as a comparator
(2017-01-01)
Wu, Chi-Jung
;
Ko, Wen-Chien
;
Ho, Mao-Wang
;
Lin, Hsi-Hsun
;
Yang, Yun-Liang
Human immuodeficency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART) and community-associated methicillin-resistant Staphylococcus aureus (CAMRSA) have increased in recent years in Taiwan. This study was undertaken to determine the prevalence of and risk factors for nasal and oral S. aureus and MRSA colonization among contemporary HIV-infected populations. Clinical variables for S. aureus and MRSA colonization among HIV-infected outpatients from three hospitals were analyzed and compared with those for oral Candida colonization. Genetic characteristics of MRSA isolates were analyzed. A total of 714 patients were screened for nasal S. aureus colonization, and a subset of 457 patients were also screened for oral S. aureus colonization. Of all patients, 79.4% were receiving HAART, and their mean CD4 count was 472 cells/mm(3). The colonization rates in the oral cavity, nasal cavity, and at either site were 18.8%, 31.7%, and 36.8%, respectively, for S. aureus, and 3.1%, 4.4%, and 5.5%, respectively, for MRSA. These rates were all much lower than the previously reported rate of oral Candida colonization (52.4%). By multivariate analysis, a suppressed viral load (< 200 copies/mL) protected against oral S. aureus, MRSA, and Candida colonization, and recent use of antibacterial agents protected against oral and nasal S. aureus colonization. Recent incarceration increased the risk of nasal MRSA colonization, while recent hospitalization, tuberculosis, older age, and intravenous drug use increased the risk of oral Candida colonization. Candida spp. did not augment S. aureus or MRSA colonization in the oral cavity. Most of the 41 MRSA isolates recovered belonged to the SCCmec IV/pvl-negative (51.2%) and VT/pvl-positive (26.8%) ST59 local prevalent CA-MRSA clones. Distinct carriage rates demonstrated here suggested that mucosal immunity against colonization might differ in terms of microbes and sites. A decreased risk in oral carriage of MRSA and Candida might be a benefit of HAART.