Advances in carbapenemase detection in Gram-negtive bacilli / 中华临床感染病杂志

With increasing use of carbapenem antibiotics , carbapenems-resistant gram-negative bacteria are spreading, and carbapenemase-producing is the main mechanism of carbapenems resistance . Rapid and accurate identification of carbapenemase and its type is of great importance to timely and effective treatment and control of infections .Chromogenic /Fluorogenic culture media, modified Hodge test and double disk synergy test are traditional methods for carbapenemase detection , but all are time-consuming. Biochemical method is more time efficient and with high sensitivity and specificity , but cannot be used to identify subtypes.Now matrix-assisted laser desorption ionization -time-of-flight mass spectrometry (MALDI-TOF MS) has been successfully applied in the identification of species , subtypes and detection of drug -resistant genes.And among various carbapenemase gene detection techniques , next generation sequencing (NGS) can also be used for the detection of integrons , transposons and plasmids, which is important in both epidemiology and resistant mechanism studies .This article reviews the advantages and disadvantages of various methods for phenotype and gene detection of carbapenemase .

Study of direct identification of pathogens from positive blood cultures by methods of separation gel tube -centrifugation / 中国基层医药

Objective To study the possibility of direct identification of pathogens from positive blood cul-tures by methods of separation gel tube -centrifugation.Methods 216 cases of positive blood culture were collected from 2015.7 to 2015.12.The bacterias were purified from blood culture bottle by separation gel tube.After washing 2 times,identified by MALDI -TOF MS.At the same time,traditional culture,smears and identification were done. Compared the results of identification by two methods.Results 216 cases of positive blood culture were single bacte-rial infection.By Gram stain,89 strains were Gram positive,119 strains were Gram negative and 8 strains were fungal spores.190 cases of positive blood culture were identified by MALDI -TOF MS,it concluded 67 Gram positive strains,111 Gram negative strains,4 anaerobe strains and 8 fungus.Compared with traditional culture,the coincidence rate reached up to 87.9%,Gram positive strains 78.8%,Gram negative strains 93.2%,anaerobe strains 100.0%and fungus 100.0%.Conclusion It takes less than 30 minutes purified from blood culture bottle by separation gel tube.And the time of identification is shorter than traditional culture.This method is good for clinical diagnosis and treatment.