Heineman H S, Chawla J K, Lopton W M
J Clin Microbiol. 1977 Nov;6(5):518-27. doi: 10.1128/jcm.6.5.518-527.1977.
Only 13 of 38 hospital laboratories surveyed include a Gram stain routinely in microbiological sputum examination. In a prospective three-hospital study, 60% of over 1,200 "sputum" specimens consisted predominantly of saliva, as judged by cell composition. Compared with the results of cultures in which microorganisms presumptively identified on sputum smears were specifically sought ("directed cultures"), cultures of the same specimens processed in the routine manner missed pneumococci 61%, haemophili 23%, and yeasts 44% of the time. The findings were similar in all three hospitals despite differences in administration, staffing, primary culture media, and workload. Unless microscopic examination is routinely included, half of all microbiological information rendered on sputum specimens is meaningless and subject to dangerous misapplication. Furthermore, culture must be guided by microscopic findings, or respiratory pathogens will frequently be missed. Finally, when routine culture and smear disagree, the culture cannot be assumed to be correct. Microscopic examination should be mandatory in sputum microbiology, both for specimen evaluation and as a guide to what to look for in culture.
在接受调查的38家医院实验室中，只有13家在痰液微生物学检查中常规开展革兰氏染色。在一项涉及三家医院的前瞻性研究中，根据细胞成分判断，1200多份“痰液”标本中有60%主要是唾液。与专门寻找痰液涂片上推测鉴定出的微生物的培养结果（“定向培养”）相比，以常规方式处理的相同标本培养，漏检肺炎球菌的概率为61%，嗜血杆菌为23%，酵母菌为44%。尽管三家医院在管理、人员配备、初代培养基和工作量方面存在差异，但研究结果相似。除非常规进行显微镜检查，否则痰液标本提供的所有微生物学信息有一半是无意义的，且可能会被危险地误用。此外，培养必须以显微镜检查结果为指导，否则呼吸道病原体常常会被漏检。最后，当常规培养和涂片结果不一致时，不能认为培养结果就是正确的。在痰液微生物学检查中，显微镜检查对于标本评估以及指导培养中寻找的目标都应是强制性的。
