1.Factors accounting for HIV antibody test false positive results in patients with rheumatoid arthritis
Yunchun LI ; Li ZHONG ; Yue WANG ; Fan YANG ; Zhongjun FANG ; Liumei DING
Chinese Journal of Laboratory Medicine 2016;39(7):522-525
Objective To investigate if immunological factors associated with the false HIV screening test results in RA.Methods Subjects who attended the Rheumatology Outpatient Clinic -Internal Medicine Unit of Guanghua Integrative Hospital , from October 2013 to October 2014, who met the American College of Rheumatology /European League Against Rheumatism Criteria for RA were recruited for the study . 100 subjects with RA were recruited.Each patient underwent clinical examination and blood sampling for assessment of serum HIV screening test and Rheumatoid factors ( RF-IgA, -IgG, -IgM) and anti-cyclic citrullinated protein antibodies (anti-CCP) were purified from the plasma and detected by ELISA , Samples were collected and processed using standard protocols and were stored in the same freezer before analysis . RA patients were divided into two groups based on the titters of RF and anti -CCP:RF <18 U/ml/anti-CCP <25 U/ml group and RF >300 U/ml /anti-CCP >500 U/ml group.HIV screening tests were determined by three methods: ELISA、Immuno-colloidal Golden Method and ECLIA.The positive results were confirmed by the Changning Centers for Disease Control , Shanghai through western -blotting test.Results 100 samples detected by ELISA and Immuno-colloidal Golden Method were given negative results , 16 positive results existed in ECLIA group.There were1,12,3 positive cases in RF-IgM <18 U/ml, RF-IgM and RF-IgG >300 U/ml group(2.7%,32.4%,13.6%;P <0.01).In anti-CCP <25 RU/ml and >500 RU/ml groups there were 2 and 4 positive results(4.7%,24.6%;P <0.01).Conclusions Different HIV screening test methods would give different results , according to operation requirement using second method to determine the HIV screening result.HIV False-positivity was associated with the titers of anti -CCP and RF in RA.
2.Distribution and transmission characteristics of thirty-five dual genotype vancomycin-resistant Enterococcus faecium carrying both vanA and vanM in an intensive care unit
Yiqun YUAN ; Li DING ; Ying ZHOU ; Pei LI ; Dongfang LIN ; Liumei DING ; Xiaogang XU
Chinese Journal of Infectious Diseases 2019;37(8):483-487
Objective To investigate the distribution and transmission characteristics of vancomycin -resistant Enterococcus faecium (VREF) carrying both vanA and vanM in the intensive care unit.Methods VREF strains were isolated from patients in the intensive care unit of Jinshan Hospital , Fudan University in Shanghai from 2013 to 2017.Antimicrobial susceptibilities of the VREF strains to nine antibiotics , including vancomycin, teicoplanin, linezolid and chloromycetin , were tested by broth microdilution method.Multiple polymerase chain reaction (PCR) was used for van genotyping and pulsed field gel electrophoresis (PFGE) was used for homology analysis.Results Thirty-five strains were mainly isolated from urine (16 strains), blood (11 strains), feces ( five strains ), bile ( two strains ) and pleural effusion ( one strain ).All the strains (100.00%) were resistant to vancomycin , ampicillin and levofloxacin , but only 40.00% were resistant to teicoplanin.All the strains were sensitive to linezolid.The results of van genotyping showed that 33 (94.3%) strains belonged to vanA and vanM dual genotype VREF, and the other two were vanA type VREF.PFGE results showed that 35 strains could be divided into 14 PFGE patterns, and seven out of 10 strains isolated in 2014 were identical and the other three belonged to three different PFGE patterns.Conclusions A dual genotype VREF carrying both vanA and vanM has been emerging and spreading in the intensive care unit of Jinshan Hospital , Fudan University in Shanghai.