1.Establishment and evaluation of multiplex PCR for detection of main pathogenic bacteria of endometritis in Tibetan sheep.
Jinhui HAN ; Meng WANG ; Yangyang PAN ; Xuequan HU ; Xingyun ZHANG ; Yan CUI ; Gengquan XU ; Libin WANG ; Sijiu YU
Chinese Journal of Biotechnology 2020;36(5):908-919
A multiplex PCR method was developed to detect the main pathogens of Qinghai Tibetan sheep endometritis. First, the genomes of five standard bacterial strains were extracted and specific primers were selected; the multiplex PCR method was established by using the genome of the standard strain as a template. The samples were collected by sterile cotton swab from Tibetan sheep uterus, and then placed in LB medium and numbered. After 48 h, the genomes of cultured bacteria were extracted and detected by single PCR method, then the positive samples were recorded. The positive samples detected by single PCR were selected for multiplex PCR detection and recorded again. The coincidence rate between these two methods was calculated to measure the accuracy of multiplex PCR. In order to identify the species of the pathogen, 30 positive samples verified by single and multiplex PCR were randomly selected for bacterial isolation and identification. In the 600 samples, the infected ratio of Streptococcus agalactiae (GBS) was 47.33%, Escherichia coli 34.83%, Staphylococcus aureus 6.5%, Salmonella and Trueperella pyogenes were negatively detected. Among the positive samples detected by multiplex PCR, the positive ratio of GBS was 45.50%, E. coli 33.50%, S. aureus 6.5%. Comparison of two detection results, Multiplex PCR detection coincidence rate is more than 95%. The isolated pathogens were identified as E. coli, GBS and S. aureus, which was consistent with the results of two methods. The multiplex PCR method was successfully established and the main pathogens of endometritis in Qinghai Tibetan sheep were GBS, E. coli and S. aureus.
Animals
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Bacteria
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genetics
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isolation & purification
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Bacteriological Techniques
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methods
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Endometritis
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microbiology
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veterinary
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Female
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Multiplex Polymerase Chain Reaction
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standards
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Polymerase Chain Reaction
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veterinary
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Sensitivity and Specificity
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Sheep
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Sheep Diseases
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microbiology
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Tibet
2.One-step methylation variable position analysis technology in single-tube.
Yang-Yang YUE ; Gui-Sen ZHAO ; Qian ZHANG ; Di LU ; Xian-Dun ZHAI ; Yao-Nan MO
Journal of Forensic Medicine 2013;29(6):419-424
OBJECTIVE:
To develop the single-tube one-step methylation variable position (MVP) analysis technology-single-tube post-digestion PCR-melting curve analysis (PDP-MCA).
METHODS:
Based on differentially methylated region (DMR) reported previously as the model, a set of primers with different melting temperatures of products in the two sides of MVP were designed. By using the FastDigest methylation-sensitive restriction enzyme (MSRE), DNA digestion, multiplex amplification, MCA detection and MCA profiles were performed in a single reaction tube. Same samples (peripheral venous blood, semen, and vaginal fluid, 5 samples each type) were tested by single-tube one step MVP and traditional MSRE-PCR MCA technology. To verify the feasibility of this method, the results were compared with that of the traditional technology. The MCA/HRM profiles of different samples were analyzed and compared.
RESULTS:
When the melting temperature of the fragments had a differential of 2 degrees C, the MCA melting peaks separated well, and MCA detection after multiplex amplification was successful. The single-tube PDP-MCA assay was developed, which integrated multiple reactions (digestion, amplification and detection) into one tube. By this method, the sample-specific profiles and data were analyzed in 2 h, which is similar to that of the traditional method. The rapid classifications of the samples were also realized.
CONCLUSION
Multiplex MVPs can be analyzed in a single closed-tube. The single-tube PDP-MCA technology is a simple, fast, and automatable method. It can be used for detection of DNA methylation variations.
DNA/isolation & purification*
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DNA Methylation/genetics*
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DNA Primers/genetics*
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Humans
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Multiplex Polymerase Chain Reaction/standards*
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Nucleic Acid Denaturation
3.Evaluation of the Xpert Clostridium difficile Assay for the Diagnosis of Clostridium difficile Infection.
Saeam SHIN ; Minkyung KIM ; Myungsook KIM ; Heejung LIM ; Heejung KIM ; Kyungwon LEE ; Yunsop CHONG
Annals of Laboratory Medicine 2012;32(5):355-358
Infection with Clostridium difficile is a growing concern because of the increasing prevalence and spread of nosocomial infections. Emergence of the hypervirulent 027/NAP1/BI strain is also notable. Existing diagnostic methods have low sensitivity or are time-consuming. Therefore, establishing a rapid and accurate microbiological diagnostic assay is needed. We evaluated the Xpert C. difficile assay (Xpert CD assay; Cepheid, USA) to detect toxigenic C. difficile. This assay is a real-time multiplex PCR assay that can be used to detect toxigenic C. difficile strains and differentiate the C. difficile presumptive 027/NAP1/BI strain. A total of 253 loose stool specimens were collected and toxigenic cultures, VIDAS C. difficile A & B assays (VIDAS CDAB assay; bioMerieux, France), and the Xpert CD assay were performed. In comparison to toxigenic cultures, the sensitivity, specificity, and positive and negative predictive values were 100%, 94.6%, 83.1%, and 100%, respectively, for the Xpert CD assay and 40.8%, 98.0%, 100%, and 88.9%, respectively, for VIDAS CDAB assay. Because of the low prevalence of the PCR ribotype 027 in Korea, the evaluation of the usefulness of the Xpert CD assay for screening for the 027 strain was limited. The Xpert CD assay provides great sensitivity in diagnosing toxigenic C. difficile infection. In addition, this method has excellent usability because it is simple and fast.
Clostridium Infections/*diagnosis/epidemiology/microbiology
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Clostridium difficile/genetics/*isolation & purification/metabolism
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Face/microbiology
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Humans
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Multiplex Polymerase Chain Reaction
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Prevalence
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Reagent Kits, Diagnostic/*standards
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Sensitivity and Specificity
4.Comparative Evaluation of Several Gene Targets for Designing a Multiplex-PCR for an Early Diagnosis of Extrapulmonary Tuberculosis.
Ankush RAJ ; Netrapal SINGH ; Krishna B GUPTA ; Dhruva CHAUDHARY ; Aparna YADAV ; Anil CHAUDHARY ; Kshitij AGARWAL ; Mandira VARMA-BASIL ; Rajendra PRASAD ; Gopal K KHULLER ; Promod K MEHTA
Yonsei Medical Journal 2016;57(1):88-96
PURPOSE: Diagnosis of extrapulmonary tuberculosis (EPTB) poses serious challenges. A careful selection of appropriate gene targets is essential for designing a multiplex-polymerase chain reaction (M-PCR) assay. MATERIALS AND METHODS: We compared several gene targets of Mycobacterium tuberculosis, including IS6110, devR, and genes encoding MPB-64 (mpb64), 38kDa (pstS1), 65kDa (hsp65), 30kDa (fbpB), ESAT-6 (esat6), and CFP-10 (cfp10) proteins, using PCR assays on 105 EPTB specimens. From these data, we chose the two best gene targets to design an M-PCR. RESULTS: Among all gene targets tested, mpb64 showed the highest sensitivity (84% in confirmed cases and 77.5% in clinically suspected cases), followed by IS6110, hsp65, 38kDa, 30kDa, esat6, cfp10, and devR. We used mpb64+IS6110 for designing an M-PCR assay. Our M-PCR assay demonstrated a high sensitivity of 96% in confirmed EPTB cases and 88.75% in clinically suspected EPTB cases with a high specificity of 100%, taking clinical diagnosis as the gold standard. CONCLUSION: These M-PCR results along with the clinical findings may facilitate an early diagnosis of EPTB patients and clinical management of disease.
Bacteriological Techniques/methods
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DNA Transposable Elements/genetics
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DNA, Bacterial/analysis/genetics
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Early Diagnosis
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Female
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Gene Amplification
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Humans
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Male
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Multiplex Polymerase Chain Reaction/*methods
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Mycobacterium tuberculosis/genetics/*isolation & purification
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Polymerase Chain Reaction/*methods/standards
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Sensitivity and Specificity
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Tuberculosis/*diagnosis
5.Prevalence of Trichomonas vaginalis in Women Visiting 2 Obstetrics and Gynecology Clinics in Daegu, South Korea.
Youn Kyoung GOO ; Won Sik SHIN ; Hye Won YANG ; So Young JOO ; Su Min SONG ; Jae Sook RYU ; Won Myung LEE ; Hyun Hee KONG ; Won Ki LEE ; Sang Eun LEE ; Won Ja LEE ; Dong Il CHUNG ; Yeonchul HONG
The Korean Journal of Parasitology 2016;54(1):75-80
This study explored epidemiological trends in trichomoniasis in Daegu, South Korea. Wet mount microscopy, PCR, and multiplex PCR were used to test for Trichomonas vaginalis in vaginal swab samples obtained from 621 women visiting 2 clinics in Daegu. Of the 621 women tested, microscopy detected T. vaginalis in 4 (0.6%) patients, PCR detected T. vaginalis in 19 (3.0%) patients, and multiplex PCR detected T. vaginalis in 12 (1.9%) patients. Testing via PCR demonstrated high sensitivity and high negative predictive value for T. vaginalis. Among the 19 women who tested positive for T. vaginalis according to PCR, 94.7% (18/19) reported vaginal signs and symptoms. Notably, more than 50% of T. vaginalis infections occurred in females younger than 30 years old, and 58% were unmarried. Multiplex PCR, which simultaneously detects pathogens from various sexually transmitted infections, revealed that 91.7% (11/12) of patients were infected with 2 or more pathogens. Mycoplasma hominis was the most prevalent co-infection pathogen with T. vaginalis, followed by Ureaplasma urealyticum and Chlamydia trachomatis. Our results indicate that PCR and multiplex PCR are the most sensitive tools for T. vaginalis diagnosis, rather than microscopy which has been routinely used to detect T. vaginalis infections in South Korea. Therefore, clinicians should take note of the high prevalence of T. vaginalis infections among adolescent and young women in order to prevent persistent infection and transmission of this disease.
Adolescent
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Adult
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Ambulatory Care Facilities/statistics & numerical data
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Female
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Humans
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Microscopy/standards
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Middle Aged
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Multiplex Polymerase Chain Reaction/standards
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Polymerase Chain Reaction/standards
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Predictive Value of Tests
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Prevalence
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Republic of Korea/epidemiology
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Sensitivity and Specificity
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Trichomonas Infections/*epidemiology/prevention & control
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Trichomonas vaginalis/physiology
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Vaginal Smears/standards
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Young Adult