Clostridium difficile carriage in infants and the characteristics of isolates / 国际检验医学杂志

Objective To investigate the carrying status and characteristics of Clostridium difficile isolated from infants.Methods Two hundred and thirty-eight stool specimens were collected from infant younger than 1 year old,that were hospitalized or outpatient from August to November 2015.Immunochromatography targeted GDH and toxin A&B of C.difficile was used for C.difficile screening,and those positive specimens were inoculated in CDIF and anaerobic culture.C.difficile isolates were genotyped by using slpA sequence typing (slpA ST),and tcdA,tcdB,cdtA and cdtB of C.difficile isolates were detected by PCR.Results Fifty C.difficile strains were isolated from 238 stool samples,and the isolated rates of C.difficile from <3 months,3 months to <6 months,and 6 months to 1 years old groups were 9.3%,17.6% and 27.3%(χ2=6.940,P=0.031<0.05),respectively.52.0%(26/50) of the C.difficile isolates were toxigenic,and 69.2% (18/26) toxigenic isolates harbored tcdA+tcdB+cdtA-cdtB-.Fifty C.difficile isolates were genotyped as 11 slpA STs,slpA ST fr-02 and kr-02 were the commonest genotypes in toxigenic C.difficile isolates;however,that was slpA ST xr-03 in non-toxigenic isolates.Conclusion High C.difficile carriage is found in infants younger than 1 year old,and more than half of C.difficile isolates are toxigenic.Most of toxigenic isolates harbored toxin A and B.The genotype of C.difficile isolates is different between toxigenic isolates and non-toxigenic isolates.

Establishment of digital polymerase chain reaction-ribotyping and database for Clostridium difficile genotyping / 中华传染病杂志

Objective To develop a digital polymerase chain reaction (PCR) ribotyping method and database for Clostridium difficile genotyping.Methods Sequencer based fluorescence capillary gel electrophoresis was used,instead of agarose gel electrophoresis,to establish the digital PCR-ribotyping of Clostridium difficile.Forty Clostridium difficile reference strains,consisting of 10 PCR-ribotypes (RT),were genotyped by the new digital PCR-ribotyping method to set-up the database.Results The sequencer based fluorescence capillary gel electrophoresis correctly detected PCR-ribotyping products of the 40 reference strains,and showed as digital figure;significant differences of these digital figures were found between the 10 RT.High similar digital figures were shown in twenty-one RT027 strains,three RT002 strains and two RT014 strains.However,seven RT001 strains were typed as four subtypes,and two RT014 strains as two subtypes,respectively.Conclusion A digital PCR-ribotyping,and a reference database consisting of 10 RT are successfully established.

Comparison of real time PCR and PCRˉreverse dot blot hybridization for detection of Human papillomavirus / 国际检验医学杂志

Objective To compare real time PCR with PCR-reverse dot blot hybridization (PCR-RDB)for detecting human pap-illomavirus (HPV)infection in women.Methods A total of 109 genital specimens from women were collected in the study.All specimens were tested HPV by using real time PCR and PCR-RDB,discrepant samples were tested again by PCR-xMAP.Results The concordant rate was 83.5%(91/109)between real time PCR and PCR-RDB (kappa=0.671),the other 18 discrepant samples were retested by PCR-xMAP,7 of those were identical with real time PCR and 11 with PCR-RDB.No differences of PCR-RDB pos-itive rates were found between the high and low viral load groups (χ2 =1.476,P =0.224).Conclusion It demonstrated moderate consistency between real time PCR and PCR-RDB.The HPV positive rates of PCR-RDB were stable when the viral loads were 103-108 .

Analysis of women′s genital human papillomavirus infection and genotype distribution in Shenzhen / 国际检验医学杂志

Objective To investigate the female human papillomavirus(HPV)infection situation in Baoan district,the HPV pos-itive rates in different age groups and the subtypes distribution.Methods PCR followed with reverse dot blot was performed to ex-amine 23 kinds of HPV genotypes in 2 627 female patients in our hospital from the January 2011 to December 2012.Results In 2 627 samples,the positive rate of HPV was 23.94% (629 cases),in which the infection rate of single low-risk type was 15.1%(95 cases),the main HPV genotype was HPV43 (7.79%);the infection rate of high-risk type was 55.17% (347 cases),the 3 most prevalent HPV genotypes were HPV52 (12.56%),HPV16 (9.86%)and HPV58 (7.79%).The multiple HPV infection ac-counted for 29.73% (187 cases).The HPV infection rates in different age groups were 50.0% in age 15-20 years,24.7% in age 21-30 years,20.8% in age 31-40 years,25.8% in age 41 -50 years,42.1% in age >50 years respectively,the differences had statistical significance.Conclusion The HPV infection rate is 23.94% in Bao′an district.The most prevalent HPV genotypes are HPV 52,16,58,43.Women in age 15-20 years old have a higher infection rate.

The clinical features of 15 cases with severe enterovirus 71 ( EV71 ) infection and the genotype of EV71 / 中国小儿急救医学

Objective To explore the clinical feature of severe enterovirus 71 (EV71) associated hand foot and mouth disease (HFMD),and genotype of EV71.Methods Fluorescent quantitation PCR was done for detecting EV71.RT-PCR was performed to amplify VP1 for sequencing and identifying genotype.A retrospective analysis was performed based on the clinical data of 15 cases with severe EV71 infection.Results EV71 nucleotide was positive in all 15 cases.The genotype of EV71 was C4.All cases had abnormal temperature and followed with nervous symptoms in the early stage.Average time was 1.26 days from onset to severe complications appearance.Eleven cases progressed to neurogenic pulmonary edema.Four cases accepted nasal continuous positive airway pressure.Eleven cases accepted oral trachea cannula mechanical ventilation.Except for 3 cases died,one case abandoned,others 11 cases were cured.Conclusion The isolated strains of EV71 in this study are all C4 genotype.All cases with severe EV71 infection were followed with nervous symptoms in the early stage,most of whom would progress to neurogenic pulmonary edema.The mortality would be cut down by using mechanical ventilation in early stage.

Detection of high-risk human papillomavirus by multiplex real time PCR / 中华检验医学杂志

Objective To investigate 13 high-risk types of HPV (HR HPV) infection rates in women with different grades of cervical lesions.Methods A total of 350 women, who were hospitalized in the department of gynecology in Bao′an Maternity & Child health hospital, were enrolled for the study.TCT technology was used to evaluate the cervical epithelium.The group were divided according to the cytology results.Multiplex real time PCR (mRT PCR) was used to detect the viral loads.HR HPV infection rate of different groups were analyzed using χ2 test or Fisher exact test.HR HPV viral loads of patients in different grades of cervical lesion groups were compared using Kruskal-Wallis or Wilcoxon test, and the age distribution of HR HPV positive group and negative group was analyzed by using Wilcoxon test.Results The HR HPV infection rates of NILM, ASCUS, LSIL, HSIL were 3.4% (10/295), 20.0% (7/35), 78.6% (11/14) and 100.0% (6/6), respectively.HR HPV positivity in NILM was lower than ASCUS (χ2=14.43,P0.05).Conclusions The present study revealed that HR HPV infection was related to cervical lesion, but there was no correlation between viral load and cervical lesion grade. In additional, no difference in age distribution was found between HR HPV positive group and negative group.