유도성 DHA-1β-Lactamase를 생성하는 폐렴 간균에 의한 균혈증이발생한 환자에게 투여된 감수성 있는 Cephalosporin의 치료실패 경험 = Failure of Cephalosporin Treatment for Bloodstream Infection Caused by Apparently Susceptible Klebsiella pneumoniae which Produced DHA-1β-Lactamase Induced by Clavulanic Acid

다국어 초록 (Multilingual Abstract)

Backgroud : The therapeutic option is limited for the infections caused by organisms producing plasmid- mediated AmpC beta-lactamases, increasingly identified worldwide. Two sporadic patients with bacteremia caused by K. pneumoniae possessing an unusual inducible β-lactam resistant phenotype were found in a university hospital.Materials & Methods : We conducted antibiotic susceptibility test according to NCCLS guideline. Also, we characterized β-lactamase by isoelectric focusing.Results : DHA-1 gene conferred the resistant phenotype. The patients had experienced treatment failure when treated with extended-spectrum cephalosporin. For the isolates the cephalosporin resistance was induced by clavulanic acid (and cefoxitin).Conclusion : Theses results suggest that the extended-spectrum cephalosporins might not provide optimal therapeutic option for inducible DHA-1-producing K. pneumoniae infection, even when the pathogens are susceptible in vitro.

국문 초록 (Abstract)

목 적:AmpC beta-lactamase를 생성하는 Klebsiella pneumoniae 균주가 보고되고 있으나 이에 대한 적절한 치료 항균제 선택에 제한이 있다. Cephalosporin 내성이 유도되는 형질을 지닌 K. pneumoniae에 의한 균혈증이 2례 발생하였다. 혈액에서 분리된 이 균주들의 내성 기전을 확인하고 항균제 감수성의 특성을 알아보고자 하였다.
방 법:NCCLS 지침에 따라 항균제 감수성 검사와 ESBL 확인 검사를 시행하였다. Isoelectric focusing과 PCR을 이용하여 beta-lactamase characterization을 시행하였다.
결 과:균주들은 DHA-1 AmpC beta-lactamase를 생성하고 있었고 clavulanic acid에 의해 cephalosporin 내성이 유도되었다. 항균제 감수성 검사 결과 내성이 아닌 광범위 cephalosporin을 투여받았으나 환자들은 치료 실패를 경험하였다.
결 론:이러한 결과들은 DHA-1을 생성하는 K. pneumoniae에 의한 중증 감염증에 광범위 cephalosporin을 투여하는 것은 감수성이 있는 항균제라 하더라도 적절한 항균제 선택이 아닐 수 있음을 시사한다

참고문헌 (Reference)

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