1.Phylogenetic characteristics, virulence and antibiotic resistance of Aeromonas caviae isolated from foodborne and environmental samples
Fanxu KONG ; Min HAO ; Hengwei WANG ; Tian TIAN ; Xifeng SHAO ; Yanyan SONG
Chinese Journal of Microbiology and Immunology 2020;40(2):91-97
Objective:To identify 49 Aeromonas caviae strains isolated form foodborne and environmental samples and analyze their virulence and antibiotic resistance. Methods:All strains were identified by VITEK and API 20NE. Two housekeeping genes, gryB and rpoD, were amplified by PCR for phylogenetic analysis. Virulence genes including act, alt, ast, lip, ahp, aerA, hlyA, ompA1 and fla were detected by PCR. In vitro antimicrobial susceptibility of these strains was tested with AST-GN16 kit. Results:Fifty-four Aeromonas caviae/ Aeromonas hydrophila strains were identified by biochemical tests. Phylogenetic analysis revealed that there were 49 Aeromonas caviae strains, four Aeromonas hydrophila strains and one Aeromonas taiwanensis strain. The positive rates of alt, lip, ompA1, fla, act, aerA and hlyA genes were 100.00%, 100.00%, 79.59%, 14.29%, 2.04%, 2.04% and 2.04%, respectively. None of the isolates carried ast or ahp gene. A total of four virulence gene combination patterns were detected, and the predominant pattern was alt/ lip/ ompA1 (32/49). Antibiotic resistance rates of the Aeromonas caviae strains to ampicillin, cefazolin, cefoxitin, amoxicillin/clavulanic acid, ceftriaxone, trimethoprim/sulfamet hoxoazole and aztreonam were 79.59%, 14.29%, 10.20%, 6.12%, 4.08%, 4.08% and 2.04%, respectively. All strains were susceptible to piparacillin/tazobactam, imipenem, amikacin, gentamicin, levofloxacin, tigacycline and nitrofurantoin. Two multidrug-resistant strains were detected. Conclusions:Aeromonas caviae/ Aeromonas hydrophila can be effectively identified by the housekeeping genes gyrB and rpoD, and the closely related Aeromonas caviae and Aeromonas taiwanensis strains can be identified by rpoD. All Aeromonas caviae strains carried two or more virulence genes and one strain isolated from environment was positive for seven virulence genes. Aeromonas caviae strains were generally resistant to penicillin, which was mainly relate to the production of β-lactamase. No strain was resistant to carbapenems, aminoglycosides, fluoroquinolones, tetracyclines or furans. Multidrug-resistant strains were observed in food and drinking water.
2.Genetic factors, risk factors and pathogenesis of cerebral palsy comorbid epilepsy
Chao GONG ; Beibei LIAN ; Xuemei LI ; Peng ZHANG ; Fanxu SONG ; Jin GUO
Chinese Journal of Child Health Care 2024;32(2):174-180
Compared to the general population, there is a higher prevalence of epilepsy in individuals with cerebral palsy (CP). Epilepsy serves as an indicator of CP severity and has a significant impact on the early survival and future quality of life of children with CP. Therefore, it is crucial to investigate the shared mechanisms underlying CP and epilepsy. This study aims to summarize the comorbidity of CP and epilepsy from genetic factors, risk factors, and pathophysiological mechanisms, in order to provide a reference for further research.