Characterization of extended-spectrum beta-lactamase-producing isolates of Haemophilus parainfluenzae.
Characterization of extended-spectrum beta-lactamase-producing isolates of Haemophilus parainfluenzae.
复制标题
副流感嗜血杆菌产广谱 β-内酰胺酶分离株的表征。
DOI：
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发表时间：
2008
影响因子：
5.2
通讯作者：
R. Davidson
中科院分区：
文献类型：
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作者：
S. Tristram;M. Pitout;K. Forward;Sarah Campbell;S. Nichols;R. Davidson
目标
描述从南非患者中回收的两株头孢噻肟耐药副流感嗜血杆菌临床分离株的β-内酰胺耐药机制。
方法
分别用脉冲场凝胶电泳和限制性内切酶分析评估分离株和质粒的相关性。对质粒介导的和染色体整合的bla（TEM）基因和ftsI基因进行测序，并使用质粒介导的bla（TEM-15）转化一系列对照生物。
结果
根据PFGE发现这两个分离株是独特的，但具有相同的编码TEM-15 β-内酰胺酶的3.7 kb质粒。两种分离株的青霉素结合蛋白3（PBP 3）也存在置换，与已知存在于β-内酰胺酶阴性氨苄青霉素耐药（BLNAR）流感嗜血杆菌菌株中的置换一致。头孢噻肟对H. influenzae、H. parainfluenzae和BLNAR H. TEM-15转化的流感嗜血杆菌的平均抑菌浓度分别为1.0、1.0和4.0 mg/L，而两个亲本的抑菌浓度分别为16.0和8.0 mg/L。副流感
结论
H.副流感病毒分离株的感染是由于质粒介导的TEM-15超广谱β-内酰胺酶与改变的PBP 3的组合可能起作用。不能排除其他耐药机制。
OBJECTIVES
To characterize the beta-lactam resistance mechanisms of two clinical isolates of cefotaxime-resistant Haemophilus parainfluenzae recovered from patients in South Africa.
METHODS
The relatedness of isolates and plasmids was assessed using PFGE and restriction enzyme analysis, respectively. Plasmid-mediated and chromosomally integrated bla(TEM) genes and ftsI genes were sequenced, and the plasmid-mediated bla(TEM-15) was used to transform a range of control organisms.
RESULTS
The two isolates were found to be unique according to PFGE, but had an identical 3.7 kb plasmid encoding a TEM-15 beta-lactamase. Both isolates also had substitutions in penicillin binding protein 3 (PBP3) consistent with substitutions known to exist in beta-lactamase-negative ampicillin-resistant (BLNAR) strains of Haemophilus influenzae. The cefotaxime MICs for control strains of H. influenzae, H. parainfluenzae and BLNAR H. influenzae transformed with the plasmid-mediated bla(TEM-15) were 1.0, 1.0 and 4.0 mg/L, respectively, compared with 16.0 and 8.0 mg/L, respectively, for the two parent H. parainfluenzae.
CONCLUSIONS
The high-level cefotaxime resistance in the H. parainfluenzae isolates was due to a combination of a plasmid-mediated TEM-15 extended-spectrum beta-lactamase with altered PBP3 probably contributing. Other contributing resistance mechanisms could not be excluded.
流感嗜血杆菌的遗传系统。
影响因子：
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作者：
Barcak,GJ;Chandler,MS;Redfield,RJ;Tomb,JF
通讯作者：
Tomb,JF