1.Establishment of duplex TaqMan RT-PCR method for detection of Entamoeba histolytica and Giardia lamblia in fecal sample
AO Ke-ping ; MENG Yan-ming ; YUAN Yu ; ZHANG Chun-ying ; MA Ying
China Tropical Medicine 2023;23(6):596-
Abstract: Objective To establish the duplex TaqMan RT-PCR method for detection of Entamoeba histolytica and Giardia lamblia in fecal samples. Methods Primer pairs and probes for Entamoeba histolytica and Giardia lamblia were designed and duplex TaqMan RT-PCR amplification system was constructed. PCR products were inserted into the pUC57 plasmid, and the lower limit of detection of the method was determined. Clinical stool samples were tested in order to evaluated the efficacy of the method. Results The detection limits of duplex TaqMan RT-PCR were 31.6 copies/μL for Entamoeba histolytica and 32 copies/μL for Giardia lamblia, respectively. Of the total of 212 clinical stool samples tested, all 3 samples with E. histolytica-positive patients by microscopy were positive by PCR, while 1 from 209 samples with E. histolytica-negative patients by microscopy were positive by PCR, and the remaining samples were negative. For Giardia lamblia, all 8 samples positive by microscopy were positive by PCR, and 1 from 204 sample with a microscopy-negative patient was positive by PCR, and the remaining samples were negative. The amplification product sequencing and blast analysis were used to confirm that the amplified sequence in the specimen of a patient with negative microscopy but positive PCR belongs to the targeted pathogen, supported by clinical symptoms and laboratory test results. PCR results for other diarrhea-causing pathogens were negative, indicating no cross-reactivity. Conclusions The dual TaqMan RT-PCR method developed in this study can not only detect microscopy-positive samples of Entamoeba histolytica and Giardia lamblia but also can detect samples that were missed by microscopy, with higher sensitivity than the microscopy method. Further, this detection method does not cross-react with other diarrhea-causing pathogens, including cross-react with other diarrhea-causing pathogens including Iodamoeba butschlii, Blastocystis hominis, Plesiomonas, Aeromonas, Salmonella, Shigella, Sphaerozoum fuscum, and Entamoeba hartmani, thus has a good specificity.
2.Distribution and drug susceptibility analysis of pathogenic bacteria for fungal bloodstream infection in 19 tertiary first-class general hospitals in Sichuan
Ke-ping AO ; Jin DENG ; Ya LIU ; Ling SHU ; Mei KANG
China Tropical Medicine 2022;22(12):1188-
Abstract: Objective To understand the distribution and drug resistance of common pathogens of fungal bloodstream infection in Sichuan, and to provide reference for clinicians to empirically treat fungal bloodstream infection. Methods From November 1, 2019 to December 31, 2020, fungal strains isolated from blood culture of patients diagnosed with bloodstream infection in 19 tertiary first-class general hospitals in Sichuan Province were collected for mass spectrometry identification and drug susceptibility, and the results were statistically analyzed, along with a retrospective analysis of clinical data. Results A total of 255 fungal strains were received and identified by mass spectrometry, 215 strains of Candida spp (84.3%), 28 strains of Cryptococcus neoformans (11.0%), 4 strains of Talaromyces marneffei (1.6%) and 8 strains of others (3.1%). Among the Candida spp 90 strains of Candida albicans, 39 strains of Candida parapsilosis complex, 36 strains of Candida glabrata, 33 strains of Candida tropicalis, 8 strains of Candida guilliermondii, and 9 strains of other Candida. In the department, the ICU was predominant, accounting for 35.7%. The top four Candida (Candida albicans, Candida parapsilosis complex, Candida glabrata, Candida tropicalis) were analyzed for drug sensitivity, Candida albicans and Candida parapsilosis complex group were more sensitive to antifungal drugs, the sensitivity rates of Candida albicans to fluconazole, voriconazole, anidulafungin, caspofungin, micarafungin were 89.2%, 92.8%, 97.6%, 97.6%, 96.4%, respectively. The sensitivity rates of Candida parapsilosis to fluconazole and voriconazole were 89.7% and 94.9%, and to anidulafungin, caspofungin and micafungin were all 100%. Echinocandins had stronger antibacterial activity against Candida spp., Candida parapsilosis complex and Candida tropicalis had 100% sensitivity to echinocandins, Candida albicans had more than 95% sensitivity to echinocandins, and Candida glabrata had about 90% sensitivity to echinocandins. Candida tropicalis was less sensitive to fluconazole and voriconazole with 66.7% and 54.5%, and the sensitivity of Candida glabrata to fluconazole was mainly concentrated in susceptible dose dependent (SDD), accounting for 91.4%. The four Candida species did not show resistance to amphotericin B, all of them showed wild-type strains, Candida tropicalis showed the highest non-wild-type rate to posaconazole and itraconazole with 21.2% and 36.4%, and the drug sensitivity results of Cryptococcus neoformans showed that 4 out of 23 strains showed resistance to amphotericin B (non-wild-type) and 3 strains showed resistance to fluconazole (non-wild-type). Conclusions The fungus of bloodstream infection is mainly Candida spp.. Among of them, Candida albicans accounts for the highest percentage, echinocandins have good antibacterial effect on Candida, Candida is sensitive to amphotericin B as wild type, but Candida tropicalis has slightly higher resistance rate to fluconazole and voriconazole, and the non-wild type rate of Cryptococcus neoformans to amphotericin B is increasing, and clinicians should pay high attention to the rational use of antifungal drugs.
3.Optimizing expression of the capsid protein VP2 from human Bocavirus and establish it's seroepidemiology assying methord.
Ye-Xia HAO ; Ji-Min GAO ; Yu JIN ; Xiao-Le LI ; Jing-Song LI ; Zhi-Ping XIE ; Yuan-Yun AO ; Xi-Qian CHEN ; Ke-Na CHEN ; Zhao-Jun DUAN
Chinese Journal of Experimental and Clinical Virology 2012;26(1):18-21
OBJECTIVETo obtain sufficient recombinant VP2 protein of human Bocavirus and establish it's seroepidemiology assying metbord. METHORD: Tbe capsid protein VP2 DNA genes of HBoV1 and 2 were optimized in accordance with tbe usage of the favorite codons in K coil so as to enhance its protein expression in prokaryotic expressing system. The protein was purified by Ni-NTA column, and its antigenicity was determined by Western Blot. Then establish ELISA to detect the specific anti-VP2 IgG antibodies against HBoV1 and 2 in healthy children aged 3-6 years in Nanjing, China.
RESULTSThe recombinant protein 6 x His-VP2 was produced in a larger quantity at 25 degrees C induced by IPTG (1 mmol/L) over night and purified by Ni-NTA column. Seropositive rates of HBoV1 and 2 were 62.2% and 55.5% and their mixed seropositivity was 37%.
CONCLUSIONThe optimizing expression of the capsid protein VP2 from human Bocavirus constructed successfully and get a high yield under certain conditions. The established ELISA could be used to further analyze seroepidemiology of HBoV in China.
Capsid Proteins ; analysis ; genetics ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Human bocavirus ; isolation & purification ; Humans ; Male ; Polymerase Chain Reaction ; Seroepidemiologic Studies
4.Treatment of femoral neck fracture with muscle-bone flap of both tensor fasciae latae and sartorius.
Guo-ping LIU ; Bin KANG ; Hui ZENG ; Yuan-ke TANG ; Xin-yu TANG ; Ao XIONG ; Xiao-chen XIE ; Wei HUANG
Chinese Journal of Traumatology 2003;6(4):238-241
OBJECTIVETo evaluate the effect of muscular pedicle bone grafts with sartorius or tensor fasciae latae and sartorius in fresh transcervical or subcapital fractures of the femoral neck.
METHODSThirty cases of fresh transcervical and subcapital fractures of the femoral neck were treated by the tail breakable screws and sartorius pedicle bone grafts (single muscular pedicle, SMP group). The other 23 cases were treated by cannulated pressure screws and bone grafts with the muscular pedicles of both sartorius and tensor fasciae latae (double muscular pedicles, DMP group).
RESULTSFifty-two cases were followed up for 3 to 5 years (mean, 4 years). In SMP group, ten cases showed poor therapeutic results. Excellent therapeutic effects were achieved in all cases of DMP group.
CONCLUSIONSThe transcervical or subcapital fractures of the femoral neck can be treated by double muscular pedicles bone graft. The bone graft with double muscular pedicles is more effective than single sartorius muscular pedicles for fresh transcervical and subcapital fractures of the femoral neck during short and medium terms.
Bone Transplantation ; Fascia Lata ; Female ; Femoral Neck Fractures ; surgery ; Humans ; Male ; Prognosis ; Surgical Flaps