生物灾害科学2025，Vol.48Issue(2)：181-190,10.DOI:10.3969/j.issn.2095-3704.2025.02.24
一株庆大霉素超高水平耐受的鞘氨醇单胞菌鉴定及其药敏性检测
Identification of a high-level gentamicin-resistant Sphingomonas strain and its antimicrobial susceptibility test
摘要
Abstract
[Objective]This study aimed to identify a high-level gentamicin resistant strain,amplify its resistance genes,and test the susceptibility of the strain to commonly used clinical antimicrobials,providing the basic data for preventing the spread of high-level antibiotic-resistant bacteria and their resistance genes in the environment.[Method]The bacterium was identified according to its colony color and morphology,the bacterial microscopic characteristics after Gram staining and the results of 16S rDNA online alignment with NCBI Nucleotide Sequence Database.The minimum inhibitory concentration(MIC)of gentamicin on the test strain was detected by agar diffusion method and trace broth method.Genes associated with high-level resistance to aminoglycosides were amplified to determine the gentamicin resistance properties of this strain.The antimicrobial susceptibility to commonly used antibacterials of this strain was tested by using Kirby-Bauer method.[Result]Given that the results of the 16S rDNA alignment was inexplicit and that it had a strong tolerance to gentamicin,the strain was initially designated the name of Sphingomonas sp.gentR in this study.Combining the results of two different methods,the test strain demonstrated an extraordinarily high-level resistance to gentamicin(MIC=40 mg/mL).PCR amplification of high-level aminoglycoside resistance genes showed the strain had two types of genes,AadA1 and Aac(6′)-Ib.Meanwhile,the antimicrobial susceptibility test results also showed that Sphingomonas sp.GentR was resistant to all aminoglycosides(kanamycin,gentamycin,tobramycin,streptomycin,and spectinomycin)except amikacin,and was also resistant to the first-generation cephalosporins,fourth-generation cephalosporins,β-lactams,nitrofurans,lincoamides,sulfonamides and polypeptide antibiotics,but was susceptible to the second-generation cephalosporins,macrocyclic lipids,tetracyclines,chloramphenicol and glycopeptides tested in this study.[Conclusion]Sphingomonas sp.gentR is the first reported Sphingomonas bacterium which has high-level gentamicin resistance,and it is resistant to many other classes of antibiotics in addition to aminoglycosides except amikacin.关键词
鞘氨醇单胞菌/庆大霉素/抗菌素耐药/高度耐药/氨基糖苷类抗生素Key words
Sphingomonas/gentamicin/antimicrobial resistance/high-level antimicrobial resistance/aminoglycosides分类
生物学引用本文复制引用
姜丽静,刘翊,王小莺,欧阳雨兰,钟世伟,李秋粉,刘宝生..一株庆大霉素超高水平耐受的鞘氨醇单胞菌鉴定及其药敏性检测[J].生物灾害科学,2025,48(2):181-190,10.基金项目
国家自然科学基金项目(31360553)和江西省自然科学基金重点项目(20202ACBL205009) （31360553）
