摘要
目的了解大理地区志贺菌耐药性分布及其对氟喹诺酮类药物的耐药机制。方法对2010～2011年从大理地区各医院收集的粪便标本进行分离培养和血清型鉴定;K-B琼脂扩散法检测分离的志贺菌对12种常见抗菌药物的耐药性;E-test法检测环丙沙星和萘啶酸对耐药菌株的最小抑菌浓度(Minimal inhibitory concentration,MIC);经PCR和DNA测序检测耐药菌株基因突变;R质粒接合试验检测氟喹诺酮类药物耐药性与R质粒介导的相关性。结果共分离到68株志贺菌,其中福氏志贺菌41株,宋内志贺菌25株,鲍氏志贺菌2株;志贺菌对萘啶酸耐药率最高,其次为复方磺胺甲噁唑、氨苄西林,对头孢曲松和头孢噻肟较敏感,对喹诺酮类显示出不同程度的耐药率;环丙沙星对志贺菌的MIC在0.008～32μg/ml之间,萘啶酸对志贺菌的MIC均≥1μg/ml,有4株MIC≥256μg/ml;6株对氟喹诺酮类药物耐药的菌株中均存在gyrA基因Ser83→Leu和parC基因Ser80→Ile的突变,其中有2株存在gyrA基因Asp87→Asn的突变,2株存在Asp87→Gly的突变,3株存在parC基因Gln91→His的突变;R质粒介导与氟喹诺酮类药物耐药无关。结论治疗细菌性痢疾首选头孢曲松和头孢噻肟,志贺菌gyrA和parC基因突变与对氟喹诺酮类药物耐药性密切相关,与R质粒介导无关。
Objective To investigate the distribution of drug-resistance and mechanism of fluoroqninolones-resistance of Shigella isolates in Dali Region, Yunnan Province, China. Methods Fecal specimens were collected from various hospitals in Dali Region in 2010 ~ 2011, from which Shigella strains were isolated, cultured and identified for serotype. The resistances of Shigella isolates to 12 routine antibacterial drugs were analyzed by K-B agar diffusion test. The minimal inhibitory concentrations （MICs） of ceflriaxome and nalidixic acid to drug-resistant Shigella strains were determined by E-test. The gene mutations of drug-resistant strains were analyzed by PCR and DNA sequencing. The relationship between resistance to fluoroqninolones and R plasmid mediation was evaluated by R plasmid conjugation test. Results A total of 68 Shigella strains were isolated, including 41 Shigellaflexner strains, 25 Shigella sonnei strains and 2 Shigella boydii strains. The resistance rate of Shigella to nalidixic acid was the highest, fol- lowed by those to sulfalene and nalidixic. The Shigella isolates were relatively sensitive to cefiriaxone and cefotaxime, while showed a certain resistance to fluoroquinolones. The MICs of ciprofloxacin to Shigella strains ranged from 0. 008 to 32 μg / ml. However, all the MICs of nalidixic acid to Shigella strains were more than 1 μg/ml, of which those to 4 strains more than 256μg/ml. Substitu- tions of Ser83 → Leu in gyrA gene and Ser80→ Ile in parC gene were observed in 6, while those of Asp87 → Asn in gyrA gene in 2, Asp87 → Gly of gyrA gene in 2, and Gln91 → His ofparC gene in 3 fluoroqninolones-resistant strains. No evidence suggested that R plasmid mediated the resistance to fluoroquinolones. Conclusion Ceftriaxone and cefotaxime were the first choice for treat- ment of bacterial dysentery. The fluoroquinolone-resistance of Shigella was closely associated with the mutations of gyrA and parC genes, while was unassociated with R plasmid mediation.
出处
《中国生物制品学杂志》
CAS
CSCD
2012年第7期855-858,共4页
Chinese Journal of Biologicals
基金
云南省教育厅基金重点项目(09Z0078)
