Jensen A, Hagelskjaer Kristensen L, Nielsen H, Prag J
Department of Clinical Microbiology, Viborg Hospital, Heibergs Allé 4, 8800, Viborg, Denmark.
Eur J Clin Microbiol Infect Dis. 2008 Jul;27(7):557-63. doi: 10.1007/s10096-008-0468-8. Epub 2008 Feb 16.
Three hundred fifty-seven isolates of Fusobacterium necrophorum from human infections in Denmark were consecutively collected over a 3 year period for the purpose of establishing the minimum requirements for rapid and reliable routine identification of Fusobacterium necrophorum using phenotypic characters. The first 40 isolates were fully characterized by the most common phenotypic tests mentioned in the literature, while the last 317 where identified solely by the established minimum requirements for rapid and reliable routine identification of Fusobacterium necrophorum. All but one isolate were identical in all phenotypic tests. The outlying strain differed in morphology and the ability to agglutinate erythrocytes. On the basis of our findings it should be possible within 3-4 days to identify and differentiate F. necrophorum from other species including other Fusobacterium spp. by the unique but subspecies specific colony morphology, susceptibility to kanamycin and metronidazole, the smell of butyric acid, chartreuse colour fluorescence, and beta-haemolysis on horse blood agar. Three-hundred fifty-six isolates were identified as F. necrophorum subsp. funduliforme while one strain was F. necrophorum subsp. necrophorum. The species and subspecies level was confirmed for the first 40 isolates by real-time PCR. MIC in mg/l was determined for the 40 isolates. MIC(90) was 0.047 for penicillin, 0.047 for clindamycin, 0.25 for metronidazole, 0.38 for cefuroxime, >32 for imipenem, 0.012 for meropenem, and 2 for erythromycin. All 357 isolates were susceptible to penicillin and metronidazole indicating that these antibiotics are still the drugs of choice in antibiotic therapy of F. necrophorum infections, but therapy with clindamycin may be an alternative. Erythromycin should be avoided.
在3年时间里，连续收集了357株来自丹麦人类感染病例的坏死梭杆菌分离株，目的是确定利用表型特征对坏死梭杆菌进行快速可靠的常规鉴定的最低要求。前40株分离株通过文献中提及的最常见表型试验进行了全面表征，而后317株仅根据已确定的坏死梭杆菌快速可靠常规鉴定的最低要求进行鉴定。除一株分离株外，所有分离株在所有表型试验中均相同。这一异常菌株在形态和凝集红细胞的能力方面有所不同。根据我们的研究结果，通过独特但亚种特异性的菌落形态、对卡那霉素和甲硝唑的敏感性、丁酸气味、黄绿色荧光以及在马血琼脂上的β溶血，应该能够在3 - 4天内将坏死梭杆菌与其他物种（包括其他梭杆菌属物种）进行鉴定和区分。356株分离株被鉴定为坏死梭杆菌亚种funduliforme，而一株为坏死梭杆菌亚种necrophorum。通过实时PCR对前40株分离株的物种和亚种水平进行了确认。测定了这40株分离株的最低抑菌浓度（MIC），以mg/l为单位。青霉素的MIC(90)为0.047，克林霉素为0.047，甲硝唑为0.25，头孢呋辛为0.38，亚胺培南>32，美罗培南为0.012，红霉素为2。所有357株分离株对青霉素和甲硝唑敏感，这表明这些抗生素仍是坏死梭杆菌感染抗生素治疗的首选药物，但克林霉素治疗可能是一种替代方案。应避免使用红霉素。
