1.Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella
Jiajun LUO ; Shihan ZENG ; Yulan HUANG ; Yulian FENG ; Fangyin ZENG ; Xiaoyan LI
Chinese Journal of Preventive Medicine 2024;58(2):248-253
By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6′)-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.
2.Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella
Jiajun LUO ; Shihan ZENG ; Yulan HUANG ; Yulian FENG ; Fangyin ZENG ; Xiaoyan LI
Chinese Journal of Preventive Medicine 2024;58(2):248-253
By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6′)-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.
3.Unveiling the oral-gut connection:chronic apical periodontitis accelerates atherosclerosis via gut microbiota dysbiosis and altered metabolites in apoE-/-Mice on a high-fat diet
Gan GUOWU ; Lin SHIHAN ; Luo YUFANG ; Zeng YU ; Lu BEIBEI ; Zhang REN ; Chen SHUAI ; Lei HUAXIANG ; Cai ZHIYU ; Huang XIAOJING
International Journal of Oral Science 2024;16(3):515-527
The aim of this study was to explore the impact of chronic apical periodontitis(CAP)on atherosclerosis in apoE-/-mice fed high-fat diet(HFD).This investigation focused on the gut microbiota,metabolites,and intestinal barrier function to uncover potential links between oral health and cardiovascular disease(CVD).In this study,CAP was shown to exacerbate atherosclerosis in HFD-fed apoE-/-mice,as evidenced by the increase in plaque size and volume in the aortic walls observed via Oil Red O staining.16S rRNA sequencing revealed significant alterations in the gut microbiota,with harmful bacterial species thriving while beneficial species declining.Metabolomic profiling indicated disruptions in lipid metabolism and primary bile acid synthesis,leading to elevated levels of taurochenodeoxycholic acid(TCDCA),taurocholic acid(TCA),and tauroursodeoxycholic acid(TDCA).These metabolic shifts may contribute to atherosclerosis development.Furthermore,impaired intestinal barrier function,characterized by reduced mucin expression and disrupted tight junction proteins,was observed.The increased intestinal permeability observed was positively correlated with the severity of atherosclerotic lesions,highlighting the importance of the intestinal barrier in cardiovascular health.In conclusion,this research underscores the intricate interplay among oral health,gut microbiota composition,metabolite profiles,and CVD incidence.These findings emphasize the importance of maintaining good oral hygiene as a potential preventive measure against cardiovascular issues,as well as the need for further investigations into the intricate mechanisms linking oral health,gut microbiota,and metabolic pathways in CVD development.
4.Clinical characteristics and long-term survival quality in single-center children with low and intermediate-risk neuroblastoma
Shihan ZHANG ; Chenghao CHEN ; Hong QIN ; Chiyi JIANG ; Qianqian LUO ; Yan SU ; Mei JIN ; Dawei ZHANG ; Huanmin WANG ; Qi ZENG ; Xiaoli MA
Chinese Journal of Applied Clinical Pediatrics 2021;36(21):1623-1627
Objective:To summarize the clinical characteristics of single-center children with low and intermediate-risk neuroblastoma (NB), report the long-term follow-up results of the growth and survival quality, and provide a basis for further clinical research.Methods:Clinical characteristics, including the sex, age, stage, risk of disease, and metastatic site of 370 newly treated children with low and intermediate-risk NB admitted to Hematology Oncology Center, Beijing Children′s Hospital from March 2007 to June 2019 were retrospectively analyzed.Kaplan-Meier method was used for survival analysis.WHO Anthro Plus was used for calculating Z score.Results:A total of 370 eligible children with low and intermediate-risk NB were included, with the mean age at onset of 16.8 months (1-191 months). Among them, 148 cases (40%) were younger than 12 months old.Mediastinal region was the most common primary site of NB (47.8%, 177 cases), followed by retroperitoneum/adrenal gland (41.4%, 153 cases). The median follow-up time of 370 patients was 31 months (0.3-157.0 months), the 5-years event free survival (EFS) and 5-year overall survival (OS) were 86.2% and 96.9%, respectively.Thirty-seven cases had growth and deve-lopment problems, of which 22 cases had stunted growth, 6 cases had low body mass, 9 cases had wasting, and 7.3%(27/370 cases) had scoliosis.5.5% of them had heart damage and 5.0%(18/357 cases) had kidney damage, involving 12 cases related to the primary tumor and 6 cases were surgically related.30.2%(95/315 cases) of them had hair changed after chemotherapy, and curly hair was the most common change.Compared with before treatment, 14.9% of the children had a personality change, with an impatient being the most common.Conclusions:The 5-year overall survival rate of the single-center large sample of low and intermediate-risk NB was high, mediastinal was the most common primary site of tumor, and the long-term quality of life is good, but there were still treatment-related side effects, and further clinical monitoring and long-term follow-up were needed.