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Objective@#To analyze the drug resistance of clinical isolates of Candida tropicalis in patients with infectious diseases, and preliminarily study their molecular characteristics.@*Methods@#95 strains of Candida tropicalis were isolated from the fungal culture specimens of 87 patients with infectious diseases in Shanghai Public Health Clinical Center from 2012 to 2015. Meanwhile, basic clinical data of patients were collected. The drug resistance of the strains to fungal drugs was analyzed by ATB FUNGUS 3 drug sensitivity test strips. All strains were classified by Multilocus sequence typing(MLST). Then, homology analysis was conducted by MEGA 5.2 software, and the evolutionary tree was mapped by using UPGMA method.@*Results@#Patients distribution of strains was rendered as following: 31 strains from TB patients, 21 strains from HIV/AIDS patients, 19 strains from patients with liver disease, and 24 strains from rare cause infection or fever patients. The drug resistance rate to five antifungal drugs commonly used in clinical (amphotericin B, 5-fluorine cytosine, fluconazole, itraconazole, voriconazole) were 2.11% (2 strains), 0, 26.32% (25 strains), 26.32% (25 strains), and 26.32% (25 strains) respectively. Among the 25 azole-resistant strains: 14 strains were from rare cause infection or fever patients, 8 strains were from HIV/AIDS patients, and 3 strains were from tuberculosis patients. In MLST, 72 sequence types (ST types) were produced, 70 of which were new types. Evolutionary tree analysis showed that 95 strains of clinical strains distribute as three large clusters. 24 azole resistant strains (96.0%) were located in CLUSER Ⅰ.@*Conclusion@#The isolated Candida tropicalis were mainly resistant to azole drugs. MLST typing indicates that they was closely related to their genetic background.
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Objective To study the molecular epidemiology of C.albicans isolates in infectious disease patients and to explore biofilm phenotypic characterization responsible for biofilm formation in clinical strains.Methods A total of 104 hospital-acquired C.alibcans clinical isolates collected from sterile sites and mucosal lesions of 92 infectious disease patients ( viral hepatitis, tuberculosis and AIDS) in Shanghai Public Health Clinical Center were analyzed.MLST analysis was performed to identify their phylogenetic status.The capability of biofilm formation was measured by [2,3-bis-(2-methoxy-4-nitro-5-sulphenyl)-2H-tetrazolium-5-carboxanilide] XTT assay.The results were compared using Kruskal-Wallis test.Results MLST analysis identified 63 DSTs with a decentralized phylogeny among 104 C.albicans isolates, of which 41 DSTs (65.1%) had not been reported in the online MLST database.The Single Locus Sequence Query from the C.albicans database identified new alleles.MEGA6 analysis of the MLST data assigned the 104 isolates within 14 of the 18 known clades; among them the clade 1 contained the greatest proportion of isolates (26.9%).Of the 43 novel DSTs isolates, 37 ( 86.0%) clustered within 11 of the 18 known clades.16 high biofilm formers were found from a total of 104 clinical isolates.The biofilm formation capabilities differed in strains isolated from different anatomical sites (H =18.23,P=0.0326).Biofilm formation by blood-originated isolates was lower than that of catheter-originated isolates ( Z=-72.20,P<0.001).Genotypes also affected the biofilm formation capability of the C.albicans isolates (H=10.01,P=0.0185).Conclusions A high level of diversity within C.albicans isolates.Microevlution clearly influences C.albicans genetic alterations upon environmental selection.The site of isolation and genotype associates with the biofilm formation capability.
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<p><b>OBJECTIVE</b>To determine the function of twin-arginine translocation system (Tat) and gene cluster in Vibrio strains and to analyze the homology of tat gene cluster among different Vibrio spp. strains based on N16961 and tatABC mutant strains N169-dtat.</p><p><b>METHODS</b>Different serotypes of biotype strains of Vibrio spp. were selected to detect the transcription of 4 genes of Tat transport system and upstream ubi aarF gene and downstream cyt551 gene by the total RNA reverse transcription and homologicity of the gene cluster by sequencing analysis.</p><p><b>RESULTS</b>Our results showed that the 4 genes of tat cluster (tatA, tatB, tatC, and tatE) were intragenic and co-transcribed. We found that ubi aarF gene could be co-transcribed with tatA, tatB, but not with tatC. The electron transport chain and energy metabolism-related genes, cytochrome C551 peroxidase gene, and 4 genes located at upstream of tatABC operon were not transcribed with tatABC. Although the co-transcription between ubi aarF and tatAB was blocked in N169-dtat strain, they were still transcribed separately. Homologous analysis of genes of tat cluster in different types of Vibrio cholerae showed that tat gene cluster was a very conservative.</p><p><b>CONCLUSION</b>The ubi and aarF gene might be co-transcribed with genes of tat cluster in Vibrio cholerae, which and the close relationship showed that they might play a key function in Vibrio cholerae.</p>
Subject(s)
Arginine , Bacterial Proteins , Cytochrome c Group , Membrane Transport Proteins , Vibrio choleraeABSTRACT
<p><b>OBJECTIVE</b>To analyze virulence genes and molecular characteristics of Vibrio parahaemolyticus isolated from sporadic cases with diarrhea in tow sentinel hospitals of Shanghai, 2010-2012.</p><p><b>METHODS</b>A total of 2 729 stool samples were collected from two surveillance sentinel hospitals in Shanghai 2010-2012. Vibrio parahaemolyticus strains were isolated and identified from diarrhea out patients using TCBS agar plates and biochemical reactions. Thermostable direct hemolysingene (tdh), thermostable-related hemolysin gene (trh), hemolysin gene (tlh) were detected by multiplex PCR method. Isolates were analyzed by PFGE and MLST. The PFGE profiles were analyzed using BioNumerics software.</p><p><b>RESULTS</b>A total of 30 clinical Vibrio parahaemolyticus strains isolated from 2 729 stool samples. The anually Vibrio parahaemolyticus isolation rate during 2010 to 2012 were 1.1%(11/973), 1.0%(11/1 120) and 1.3%(8/636) respectively. The PCR positive rates of virulence genes tlh, tdh and trh were 100%, 97% and 0 respectively. The Vibrio parahaemolyticus strains were divided into 13 PFGE types (P1-P13)and 3 ST types (ST-189, ST-799, ST-3). Among 13 PFGE types, P4 was the main PFGE type, accounting for 30%(9/30). P9, P10 were accounting for 12% (4/30) respectively, P1, P2, P12, P13 were accounting for 7%(2/30) respectively, the others types were 3%(1/30) respectively. MLST analysis results showed there are three ST types, ST3 was 84%(25/30), ST189 and ST799 were accounting for 13% (4/30) and 3% (1/30) respectively.</p><p><b>CONCLUSION</b>The infection rate of Vibrio parahaemolyticus was not very high from 2010-2012 in Shanghai, all strains were positive for tlh and negative for trh. ST3 was the major type of Vibrio parahaemolyticus.</p>