Analysis of drug resistance and molecular characteristics of Listeria monocytogenes from food and clinical sources in Guizhou Province in 2022
This study was aimed at understanding the serotypes,virulence,drug resistance,and genetics of the pathogenic genes from 29 strains of foodborne Listeria monocytogenes in Guizhou Province in 2022.The minimum inhibitory concentration(MIC)values against eight antibiotics were determined with the microbroth dilution method,and whole genome sequencing was performed on 29 L.monocytogenes strains isolated from food microbiology and foodborne disease surveillance efforts in the province in 2022.The genome sequences were assembled,and bioinformatics analyses were conducted to examine genealogy,serogroups,sequence analysis(ST type),clonal groups(CC type),resistance genes,and virulence genes.A total of 29 strains of L.monocytogenes had resistance to zero to eight antibiotics,and carried six resistance genes.All strains of L.monocytogenes carried fosX,mprF,Lin,and norB.The 29 strains of L.monocytogenes belonged to 2 lineages(Ⅰ and Ⅱ):17 strains belonged to lineage Ⅱ,which was the dominant strain,and 12 strains belonged to lineage Ⅰ.The strains were classified into 13 ST types,among which ST8 was dominant,accounting for 31.03％(9/29 strains),and was followed by ST619 and ST121,accounting for three strains each.The strains were di-vided into four serogroups,with 15 strains in serogroups 1/2a and 3a;11 strains in serogroups 1/2b,3b,and 7;2 strains in serogroups 1/2c and 3c;and 1 strain in serogroups 4b,4d,and 4e.The strains were divided into 12 CC types,and one unsub-divided CC type,ST2348,among which CC8 was dominant,accounting for 27.59％(nine strains).A total of 25 virulence genes were found,which belonged to three virulence islands(LIPI-1,LIPI-2,and LIPI-3)and 23 CL types,including one or two strains each,and three CL types including two strains each.Foodborne L.monocytogenes in Guizhou Province has a low level of drug resistance,carries a high number of virulence genes,and shows genetic diversity in serogroups and molecular phe-notypes.These findings should strengthen the continuous surveillance efforts for Listeria monocytogenes.
万方数据
维普
