Résumé
Strain-resource engineering is often considered as an important infrastructure of microbiology related research and industry. The western developed countries took the lead in establishing the classical microbial resource utilization method, and continuously improved the preservation system, species annotation technology and global sharing mechanism, which realized the expansion and reserve of biological resources since end of the 19th century. The rich and diversified germplasm resources, standard strains and production strains not only have important economic values, but also maintain the advantages of scientific research, bioeconomy (such as antimicrobial agents, vaccines, detection reagent development and standard development, etc.) and national security. Although there has been a lot of progress in related research in recent years, compared with developed countries, there is still a big gap in related fields in China. The investment and top-level design in this area lag far behind the western developed countries, and it is not commensurate with the current level of economic and social development in my country. Drawing lessons from the practice of WFCC and WDCM (World Data Center for Microorganisms, Global microbial data Center, affiliated to WFCC), for the purpose of collecting new clinical species/strains, this paper puts forward some suggestions on the identification, preservation and upload system of isolates.
Résumé
Objective:To quantitatively analyze the clinical and drug resistance feature of diarrhea of adults patients in 2016 and 2019 induced by the Escherichia coli (diarrheagenic Escherichia coli, DEC), and to reveal the difference of DEC′s epidemiological features of before and after measuring to strengthen food hygiene and safety in Beijing. Methods:A total number of 3 408 patients with food-borne adult diarrhea were received diagnosis and treatment in the intestinal clinic department of Beijing Tongren Hospital in 2016 and 2019.There were 1 926 patients in 2016 and 1 482 in 2019, respectively. The clinical information of patient were entered into the intestinal early warning system and were carefully preserved. The clinical specimens (the stool samples) were isolated and the DECs were identified by culturing. The colony of DECs was identified by matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Five pathogenic types of Escherichia coli were classified by multiplex PCR methods. The drug-susceptibility test was performed according to the standards of the American Society for Clinical and Laboratory Standardization in 2019. The categorical data were analyzed by χ 2 test or Fisher′s exact test to verify the statistical difference. Results:A total number of 581 DECs strains were detected in 3 408 specimens. Among the subtypes of E Coli, the Enterotoxigenic Escherichia coli (ETEC) accounted for 53.36% (310/581), and Enterohemorrhagic Escherichia coli (EHEC) was detected. In 2016, the total detection rate of DEC was 14.54% (280/1 926), enteroaggregative Escherichia coli (EAEC) accounted for 18.21% (51/280), and ETEC accounted for 71.79% (173/280). In 2019, the total detection rate of DEC was 20.31% (301/1 482), EAEC accounted for 41.23% (116/301), and ETEC accounted for 48.93% (137/301). Compared with 2016, the detection rate of EAEC in 2019 increased significantly (χ2=29.26, P<0.001), followed by EPEC (χ2=9.37, P=0.002), and ETEC decreased (χ2=15.43, P<0.001). Compared with other pathogenic types, EAEC can easily cause nausea(χ2=32.72, P<0.001).The red blood cells(χ2=16.44, P=0.001) or the white blood cells (χ2=26.82, P<0.001) could be easily observed in stool specimens of patients infected with enteroinvasive Escherichia coli (EIEC). The resistance rates of EIEC to ampicillin, ampicillin/sulbactam and gentamicin were 80.95% (17/21), 66.67% (14/21) and 57.14% (12/21), respectively. Three strains of EAEC resistant to carbapenem antimicrobials were discovered in 2019 and of which two strains were resistant to ertapenem and imipenem, and the other one strain was only resistant to ertapenem. The whole genomic sequencing showed that there are multiple resistance mechanisms: including the mainly drug-resistant nodular cell differentiation family efflux pump, penicillin binding site mutation, and New Delhi metal-β-lactamase 5 production. Conclusions:The detection rate of DECs in adult patients with food-borne diarrhea is high, and the foremost subtype of DECs is ETEC. Compared with 2016, the detection rates of ETEC in clinical specimens decreased in 2019, and the detection rate of EAEC increased significantly, respectively. In 2019, a carbapenem-resistant antibacterial drug-resistant Escherichia coli strain was isolated. It is of great significance to focus on the biological characteristics and epidemiological changes of DEC.