ABSTRACT
We employed a multiplex polymerase chain reaction (PCR) coupled with capillary electrophoresis (mPCR-CE) targeting six Clostridium difficile genes, including tpi, tcdA, tcdB, cdtA, cdtB, and a deletion in tcdC for simultaneous detection and characterization of toxigenic C. difficile directly from fecal specimens. The mPCR-CE had a limit of detection of 10 colony-forming units per reaction with no cross-reactions with other related bacterial genes. Clinical validation was performed on 354 consecutively collected stool specimens from patients with suspected C. difficile infection and 45 isolates. The results were compared with a reference standard combined with BD MAX Cdiff, real-time cell analysis assay (RTCA), and mPCR-CE. The toxigenic C. difficile species were detected in 36 isolates and 45 stool specimens by the mPCR-CE, which provided a positive rate of 20.3% (81/399). The mPCR-CE had a specificity of 97.2% and a sensitivity of 96.0%, which was higher than RTCA (x = 5.67, P = 0.017) but lower than BD MAX Cdiff (P = 0.245). Among the 45 strains, 44 (97.8%) were determined as nonribotype 027 by the mPCR-CE, which was fully agreed with PCR ribotyping. Even though ribotypes 017 (n = 8, 17.8%), 001 (n = 6, 13.3%), and 012 (n = 7, 15.6%) were predominant in this region, ribotype 027 was an important genotype monitored routinely. The mPCR-CE provided an alternative diagnosis tool for the simultaneous detection of toxigenic C. difficile in stool and potentially differentiated between RT027 and non-RT027.
Subject(s)
Humans , Clostridium Infections , Diagnosis , Clostridioides difficile , Genetics , Electrophoresis, Capillary , Feces , Microbiology , Genes, Bacterial , Polymerase Chain Reaction , Ribotyping , Sensitivity and SpecificityABSTRACT
In recent years, the incidence of hepatocellular carcinoma (HCC) has risen year by year, leading to a high mortality rate. At present, surgical treatment is the major cure for HCC, and in general, HCC is diagnosed at late stages. Due to the heterogeneity of HCC and different sensitivities to drugs, the treatment efficacy of advanced HCC is poor. In this paper, we retrospectively analyzed the prog-ress of HCC treatments and reviewed important progression, which provides new view for the clinical improvement of the total surviv-al of patients with HCC.
ABSTRACT
Objective To develop an accurate,rapid,high throughout genotyping method based on oligonucleotide microarray for cytochrome P450 gene polymorphisms related to paclitaxel metabolism.Methods The mutant points of 2C8 * 3,3A4 * 18 and 3A5 * 3C from cytochrome P450 gene were regarded as targets.Based on the sequences in the GenBank,the wild-type and mutant-type probes were specially designed for each mutant point.PCR primers were located in the both sides of mutant point,and furthermore the fragments of PCR products were less than 200 bp.Each type of standard plasmids was constructed.Thus,all the olignucleotide probes were modified with 3'amino-group,and the reverse primers were labeled with fluorescein (Cy3).The probes were immobilized onto certain glass slides.The specific fragments of three genes were amplified and then hybridized with oligonucleotide microarray.The results were analyzed by using certain software.Finally this assay was applied to detect 50 clinical blood specimens.Results When PCR products from standard plasmids were hybridized with DNA microarray,the corresponding probes produced positive signals.Meanwhile,the non-specific hybridization signals did not appear.The results of clinical specimens showed that the mutant rate of CYP2C8 * 3 was 2%.The point of CYP3A4 * 18 for all the clinical specimens was wild-type and the mutant rate of CYP3A5 * 3C was 62%. Meanwhile,the results from detecting 50 clinical blood specimens using oligonucleotide microarray were the same as sequencing analysis.Conclusions Oligonucleotide microarray is a reliable and accurate genotyping assay for cytochrome P450 2C8 * 3.3A4 * 18 and 3A5 * 3C polymorphisms related to paclitaxel simultaneously.This genotyping assay is a high-throughout method for guiding personalized therapy and analyzing metabolism of paclitaxel in vivo.