Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three t...Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannanbinding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP.Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays.Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05).Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.展开更多
Objective： The aim of the study was to detect the levels of mannose-binding lectin （MBL）, MBL-associated serine protease 2 （MASP-2） and explore the clinical significances of them in patients with primary thyroid ...Objective： The aim of the study was to detect the levels of mannose-binding lectin （MBL）, MBL-associated serine protease 2 （MASP-2） and explore the clinical significances of them in patients with primary thyroid neoplasms. Methods： By using ELISA method, we detected the serum levels of MBL and MASP-2 in 26 patients with papillary thyroid carcinoma （PTC）, 30 patients with thyroid adenoma （TA） and 26 healthy people, respectively. Results： Serum MBL level was （565.23 ± 76.70） μg/L in PTCs higher than （324.267 ±24.74） μg/L in TAs, and （152.69± 16.95） IJg/L in healthy of controlling group. There was statistical significance between PTC and TA （P 〈 0.05）, however there was no difference between TA and healthy （P 〉 0.05）. Serum MASP-2 level was （726.153± 78.88） pg/L in PTCs higher than （379.266 ± 30.26） μg/L in TAs, and （203.846 ± 29.09） μg/L in healthy. Serum MASP-2 level was higher in PTCs than TAs, and the difference had statistical significance （P 〈 0.01）. But no difference was observed between in TAs and healthy. Conclusion： These findings might reflect inflammatory processes induced by defense mechanisms, in response to the development of the turnout. MBL may also be involved in the elimination of possible tumourigenic pathogens.展开更多
Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity...Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity chromatographyon mannan-Sepharose 4B column.Its binding ability to eight species,97 stratus of bacteria was detected by enzyme-linked lectinassay(ELLA).Results:MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolvticaand Escherichia coli,but shows relatively lower binding ability to Staphylococcus haemolyticus,Enterobacter cloacae andStaphylococcus epidermidis.To different isolates of Klebsiella pneumoniae,Haemophilus influenzae and Staphylococcus aureus,MBL shows quite different binding ability.Conclusions:MBL has different binding ability to different bacteria,and has relativelystronger binding ability to Gram-negative bacteria.Its binding ability to different isolates of certain kinds of bacteria is quitedifferent.展开更多
Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum leve...Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum level and function. The aim of this study was to investigate the frequency of different MBL2 genotypes in neonatal sepsis among patients of neonatal intensive care unit (NICU). Two hundred and forty-five neonates were enrolled in this study (127 infected and 118 uninfected controls). Multiplex PCR and double amplification refractory mutation system (dARMS) were used for typing of MBL2 exon1 and promoter respectively. Klebsiella species were the most frequently isolated organisms (22.8%). There is no statistical significance difference in the distribution of different expression genotypes between infected group and controls (P = 0.11). However, prevalence of low MBL2 expression genotypes (XA/O and O/O) was higher in infected patients compared to control group (patients 25.2% and controls 15.3%). Low and medium MBL2 expression genotypes were mostly associated with Gram-negative bacterial infections (18.9% and 22.8%) respectively. A statistically significant association of Gram-negative bacterial infections with low MBL2 expression genotypes was found (P = 0.02). Higher frequency of AB and BB genotypes was observed (31.5% and 7.9%) in patients group compared to control, but without statistical significant difference.展开更多
基金funded by the National Key R&D Program of China[2021YFC2301102]National Natural Science Foundation of China[82202593]Key R&D Program of Hebei Province[223777100D].
文摘Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannanbinding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP.Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays.Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05).Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.
基金Supported by a grant of Natural Science Funds Projects of Hebei Province (No. C2008001306)
文摘Objective： The aim of the study was to detect the levels of mannose-binding lectin （MBL）, MBL-associated serine protease 2 （MASP-2） and explore the clinical significances of them in patients with primary thyroid neoplasms. Methods： By using ELISA method, we detected the serum levels of MBL and MASP-2 in 26 patients with papillary thyroid carcinoma （PTC）, 30 patients with thyroid adenoma （TA） and 26 healthy people, respectively. Results： Serum MBL level was （565.23 ± 76.70） μg/L in PTCs higher than （324.267 ±24.74） μg/L in TAs, and （152.69± 16.95） IJg/L in healthy of controlling group. There was statistical significance between PTC and TA （P 〈 0.05）, however there was no difference between TA and healthy （P 〉 0.05）. Serum MASP-2 level was （726.153± 78.88） pg/L in PTCs higher than （379.266 ± 30.26） μg/L in TAs, and （203.846 ± 29.09） μg/L in healthy. Serum MASP-2 level was higher in PTCs than TAs, and the difference had statistical significance （P 〈 0.01）. But no difference was observed between in TAs and healthy. Conclusion： These findings might reflect inflammatory processes induced by defense mechanisms, in response to the development of the turnout. MBL may also be involved in the elimination of possible tumourigenic pathogens.
文摘Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity chromatographyon mannan-Sepharose 4B column.Its binding ability to eight species,97 stratus of bacteria was detected by enzyme-linked lectinassay(ELLA).Results:MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolvticaand Escherichia coli,but shows relatively lower binding ability to Staphylococcus haemolyticus,Enterobacter cloacae andStaphylococcus epidermidis.To different isolates of Klebsiella pneumoniae,Haemophilus influenzae and Staphylococcus aureus,MBL shows quite different binding ability.Conclusions:MBL has different binding ability to different bacteria,and has relativelystronger binding ability to Gram-negative bacteria.Its binding ability to different isolates of certain kinds of bacteria is quitedifferent.
文摘Mannose binding lectin (MBL) is an important component of innate immunity particularly in neonates whose adaptive immunity is not fully developed. Polymorphism in MBL2 gene promoter and exon1 determines MBL serum level and function. The aim of this study was to investigate the frequency of different MBL2 genotypes in neonatal sepsis among patients of neonatal intensive care unit (NICU). Two hundred and forty-five neonates were enrolled in this study (127 infected and 118 uninfected controls). Multiplex PCR and double amplification refractory mutation system (dARMS) were used for typing of MBL2 exon1 and promoter respectively. Klebsiella species were the most frequently isolated organisms (22.8%). There is no statistical significance difference in the distribution of different expression genotypes between infected group and controls (P = 0.11). However, prevalence of low MBL2 expression genotypes (XA/O and O/O) was higher in infected patients compared to control group (patients 25.2% and controls 15.3%). Low and medium MBL2 expression genotypes were mostly associated with Gram-negative bacterial infections (18.9% and 22.8%) respectively. A statistically significant association of Gram-negative bacterial infections with low MBL2 expression genotypes was found (P = 0.02). Higher frequency of AB and BB genotypes was observed (31.5% and 7.9%) in patients group compared to control, but without statistical significant difference.
