Maslow J N, Brecher S M, Adams K S, Durbin A, Loring S, Arbeit R D
Infectious Diseases Section, VA Medical Center, Boston, Massachusetts 02130.
J Clin Microbiol. 1993 Aug;31(8):2000-3. doi: 10.1128/jcm.31.8.2000-2003.1993.
Klebsiellae are an important cause of nosocomial infections. The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive. We report here the detailed biochemical and molecular analysis of two isolates of Klebsiella, cultured from the same urine specimen, that differed only in their ability to produce indole. The two isolates were identical as determined by ribotyping and pulsed-field gel electrophoresis, and they differed from 10 epidemiologically unrelated strains. Probing with the Escherichia coli tryptophanase operon, tna, revealed seven restriction fragment length polymorphisms (RFLP) among the 12 strains. The two index strains had identical RFLP; no single RFLP could account for all of the indole-positive or -negative strains. Thus, the identification of epidemiologically related strains of Klebsiella differing only in indole production may warrant further examination to determine whether the strains are clonal.
克雷伯菌属是医院感染的重要病因。两种与临床相关的菌种，即肺炎克雷伯菌和产酸克雷伯菌，可通过从色氨酸产生吲哚的能力来区分，产酸克雷伯菌吲哚呈阳性。我们在此报告了从同一尿液标本中培养出的两株克雷伯菌的详细生化和分子分析，这两株菌仅在产生吲哚的能力上有所不同。通过核糖体分型和脉冲场凝胶电泳确定，这两株菌是相同的，并且它们与10株流行病学上不相关的菌株不同。用大肠杆菌色氨酸酶操纵子tna进行探针检测，在12株菌株中发现了7种限制性片段长度多态性（RFLP）。这两株索引菌株具有相同的RFLP；没有单一的RFLP能够解释所有吲哚阳性或阴性菌株。因此，鉴定仅在吲哚产生方面不同的流行病学相关克雷伯菌菌株可能需要进一步检查，以确定这些菌株是否为克隆株。
