Objective To analyze the molecular characteristics of qnrS-positive Escherichia coli ( E. coli) strains resistant to quinolone. Methods A total of 57 qnrS1-positive clinical isolates were collect-ed from Fujian Medical University Union Hospital. Plasmid-mediated quinolone resistance ( PMQR) genes [qnrA, qnrB, qnrC, qnrD, aac(6′)-Ib-cr, qepA and oqxAB] andβ-lactamase genes (blaCTX-M-1, blaCTX-M-2, blaCTX-M-8 , blaCTX-M-9 , blaSHV and blaTEM ) were detected by PCR and then sequenced. Agar dilution method was used to analyze the antimicrobial susceptibility of the qnrS1-positive strains. Phylogenetic analysis was conducted using PCR. Multilocus sequence typing ( MLST) was performed for phenotyping. Enterobacterial repetitive intergenic consensus-polymerase chain reaction ( ERIC-PCR) was used to evaluate the genetic sim-ilarity between those isolates. Transferability of the qnrS1 genes carried by the 57 strains was examined by conjugation test with the sodiumazide-resistant E. coli J53 as the recipient strain. Mutations in the quinolone resistance-determining regions ( QRDR) in those strains were analyzed by PCR. Results All of the qnrS1-positive E. coli strains showed high resistance to quinolones. PMQR genes were harbored by 14 (24. 6％) isolates. Extended spectrum β-lactamases (ESBLs)-producing isolates accounted for 68. 4％. Mutations in the QRDR of gyrA, gyrB, parC and parE genes were found in 56 (98. 2％) strains and the most frequent point mutations were S83L (89. 5％) in gyrA gene, S80I (54. 4％) in parC gene and P415V (28. 1％) in parE gene. The qnrS1 gene was successful transferred from 13 (22. 8％) isolates to E. coli J53 by conjuga-tion. Five plasmid incompatibility groups were detected. Phylogenetic analysis showed that there were 36 (63. 2％), 13 (22. 8％), 1 (1. 8％) and 7 (12. 3％) isolates belonging to groups A, B1, B2 and D, respectively. The 57 qnrS1-positive E. coli strains were assigned to 50 ERIC types and 39 sequence types ( ST) based on the results of ERIC-PCR and MLST. Conclusions Mutations in the QRDR in E. coli strains were associated with qnrS1 gene and might play a critical role in the dissemination of quinolone-resistant bacteria.

Objective: To investigate the prevalence and associated factors of sexting among college students in Jiangxi Province, so as to provide a reference for sexual education interventions in colleges. Methods: A combined method of random cluster sampling and convenience sampling was used to conduct an anonymous questionnaire survey on 13 042 students from 14 colleges in Jiangxi Province in October 2023. A self designed questionnaire was used to collect data on sexting among students, and Chi square tests and binary Logistic regression analysis were conducted to explore the factors associated with sexting among college students in Jiangxi Province. Results: The reported rate of sexting among college students in Jiangxi Province was 11.5%. Binary Logistic regression analysis showed that female students, non only children, and those who do not view pornographic novels/videos/films had a lower likelihood of engaging in sexting ( OR =0.72, 0.83, 0.23, P <0.05). Students who identified as homosexual, lacked knowledge about AIDS, did not mind premarital sex, and had indifferent attitudes towards multiple sexual partners were more likely to engage in sexting ( OR =1.66, 1.53, 1.25, 2.26, 1.78, P <0.05). Students who smoke, drink, and report a history of high risk sexual behavior were more likely to engage in sexting behavior ( OR=1.38-12.20, P <0.05); night owls showed a negative correlation with sexting behavior ( OR=0.24-0.58, P <0.05). Conclusions A significant proportion of college students in Jiangxi Province engage in sexting. It is recommended that colleges and universities strengthen their sexual education efforts and focus on cultivating internet literacy to promote the physical and mental health development of college students.