Cell Wall-Deficient Bacteria: Basic Principles and Clinical Significance
Cell Wall-Deficient Bacteria: Basic Principles and Clinical Significance
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细胞壁缺陷细菌：基本原理和临床意义
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发表时间：
1983
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通讯作者：
S. Edberg
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作者：
S. Edberg
细胞壁缺陷细菌：基本原理和临床意义由19章(524页)和一系列附录(53页)组成。这本书的作者都很有资质，都发表了该领域的原创研究成果。细菌被外骨骼覆盖，外骨骼由肽聚糖组成的分子合胞体组成。随着微生物的生长，裂解酶打破细胞壁，允许细胞膜内的原生质扩张。然后细胞壁在扩大的微生物周围重塑。当微生物通过二次分裂进行分裂时，自溶酶再次打破细胞壁，在分裂的细胞中间形成隔膜。一些最有用和最无害的抗生素通过干扰细胞壁的合成来发挥作用。例如，青霉素干扰D-丙氨酸残基的末端交联。在青霉素存在下生长的细胞会产生长丝，因为细胞膜中的原生质增大，但分子合胞体不覆盖细胞膜。这些相当奇怪的形态类型偶尔会在接受抗生素治疗的患者的临床标本中发现。当微生物被不完全的肽聚糖覆盖时，它被称为球体；当微生物剥离细胞壁，产生只被细胞膜包围的球形有机体时，它被称为L型。支原体是一种单细胞动物，具有细菌的所有属性，但没有细胞壁。其他临床上有用的影响细胞壁合成的药物是头孢菌素和万古霉素。在该书的基本原理部分，作者讨论了L型细菌的基本生物学、血清学和免疫学特征，以及细胞壁缺陷细菌与支原体的关系。这一部分相当完整，涵盖了1981年前有关这些主题的知识。值得祝贺的是，编辑和作者进行了细致的、参考充分的讨论。细胞壁缺陷细菌已经存在了50年，但它们的临床意义一直存在争议。本书的第二部分，关于临床意义，试图回答这个问题。多年来，特别是在20世纪70年代初至70年代中期，许多临床微生物学实验室使用特殊的培养基试图分离细胞壁缺陷细菌。他们一般都不成功，这种做法在很大程度上已经被放弃，除了培养病人，根据临床印象，应该有积极的文化，但没有。一些实验室仍在使用这些培养液进行血液培养。确定CWDB是否存在于体液中的一个问题是，它们在常规细菌培养基继代培养时往往会恢复正常形态。在这本书的最后14章中，作者回顾了关于这些微生物的临床意义的已知情况。许多临床微生物学和传染病从业者认为，细胞壁缺陷细菌可能是生物体在特定身体部位持续存在并导致复发的原因。
Cell Wall-Deficient Bacteria: Basic Principles and Clinical Significance consists of 19 chapters (524 pages) and a series of appendices (53 pages). The authors of this book are well qualified, all having published original research in the area. Bacteria are covered with an exoskeleton, made up of a molecular syncytium composed of peptidoglycan. As the microbe grows, lytic enzymes break the cell wall to allow expansion of the protoplasm within the cell membrane. The cell wall then reforms around the enlarged microbe. When the microbe divides by binary fission, autolytic enzymes again break the cell wall and a septum is formed in the middle of the dividing cell. Some of the most useful and benign antibiotic agents work by interfering with cell wall synthesis. For example, penicillin interferes with the terminal cross-linking of D-alanine residues. A cell grown in the presence of penicillin produces long filaments because the protoplasm in the cell membrane enlarges but the molecular syncytium does not cover it. These rather bizarre morphological types are occasionally found in clinical specimens of patients receiving antibiotics. When a microbe is covered with incomplete peptidoglycan, it is known as a spheroplast; when the microbe sheds its cell wall to produce a spherical organism bounded solely by the cell membrane, it is known as an L-form. Mycoplasmas are single-celled animals that have all the attributes of bacteria but no cell walls. Other clinically useful agents that affect cell wall synthesis are the cephalosporins and vancomycin. In the basic principles section of the book (120 pages), the authors discuss the basic biology, serologic and immunologic characteristics, formation of L-form bacteria, and the relationship between cell wall-deficient bacteria (CWDB) to the mycoplasmas. This section is quite complete and covers knowledge of these subjects through 1981. The editor and the authors are to be congratulated for the meticulous and well-referenced discussion. Cell wall-deficient bacteria have been known to exist for 50 years, but their clinical significance has been a matter of debate. The second section of the book, concerning clinical significance, attempts to answer this question. For many years, especially in the early to mid-1970s, many clinical microbiology laboratories employed special media in an attempt to isolate cell wall-deficient bacteria. They were generally unsuccessful, and this practice has largely been abandoned except for the culturing of patients that, by clinical impression, should have a positive culture but do not. Some laboratories still use these media for blood culturing. One of the problems of establishing if CWDB are present in body fluids is that they tend to revert to normal forms on subculture to routine bacteriological medium. In the last 14 chapters of this book, the authors review what is known concerning the clinical significance of these microbes. Many clinical microbiology and infectious diseases practitioners feel that cell wall-deficient bacteria may be responsible for the persistence of an organism in a particular body site and lead to relapse 49