Dudley S, Ashe K, Winther B, Hendley J O
Department of Clinical Microbiology, University of Virginia Health System, Charlottesville, 22908, USA.
J Lab Clin Med. 2001 Nov;138(5):338-42. doi: 10.1067/mlc.2001.119311.
Carriage rates for the bacterial pathogens associated with otitis media (Streptococcus pneumoniae [SP], Hemophilus influenzae [HI], and Moraxella catarrhalis [MC]) are of interest. Culture on three selective agars was compared with culture on two standard agars to determine the more accurate method for detection of these species in the nasopharynx of healthy children. Weekly samples were obtained in winter from 18 healthy children (ages 1 through 9 years) as part of a longitudinal study. A 0.1-mL sample of 116 nasopharyngeal aspirate/washes was inoculated onto each of five agars. Two were standard (sheep blood and chocolate), and three were selective (blood with gentamicin for SP; chocolate with vancomycin, bacitracin, and clindamycin for HI; blood with amphotericin B, vancomycin, trimethoprim, and acetazolamide for MC). One technician read the standard plates and another the selective; both were blinded to the results of the other. SP was found in 44% of samples with selective agar versus 25% with standard agar; HI was found in 31% with selective versus 9% with standard; MC was found in 56% with selective versus 37% with standard. Overall, 80% of samples had one or more pathogens detected with selective agars as compared with 58% with standard agars (P =.0004). Selective agars were more accurate than standard agars for detecting otitis pathogens in the nasopharynx, where they are a common part of normal flora in healthy children.
与中耳炎相关的细菌病原体（肺炎链球菌[SP]、流感嗜血杆菌[HI]和卡他莫拉菌[MC]）的携带率备受关注。将在三种选择性琼脂上的培养结果与在两种标准琼脂上的培养结果进行比较，以确定在健康儿童鼻咽部检测这些菌种的更准确方法。作为一项纵向研究的一部分，在冬季每周从18名健康儿童（1至9岁）获取样本。将116份鼻咽抽吸物/冲洗液的0.1毫升样本接种到五种琼脂上。两种是标准琼脂（羊血琼脂和巧克力琼脂），三种是选择性琼脂（含庆大霉素的血琼脂用于检测SP；含万古霉素、杆菌肽和克林霉素的巧克力琼脂用于检测HI；含两性霉素B、万古霉素、甲氧苄啶和乙酰唑胺的血琼脂用于检测MC）。一名技术人员读取标准平板的结果，另一名读取选择性平板的结果；两人都对对方的结果不知情。使用选择性琼脂时，44%的样本检测到SP，而使用标准琼脂时为25%；使用选择性琼脂时，31%的样本检测到HI，而使用标准琼脂时为9%；使用选择性琼脂时，56%的样本检测到MC，而使用标准琼脂时为37%。总体而言，使用选择性琼脂时，80%的样本检测到一种或多种病原体，而使用标准琼脂时为58%（P = 0.0004）。对于在健康儿童正常菌群中常见的鼻咽部中耳炎病原体检测，选择性琼脂比标准琼脂更准确。
