Manifestations and complications of Mycoplasma pneumoniae disease: a review

Over the past 20 years the annual number of reports on extrapulmonary symptoms during Mycoplasma (M.) pneumoniae disease has increased. Clinical and epidemiological data indicate that symptoms from the skin and mucous membranes, from the central nervous system, from the heart, and perhaps from other organs as well are not quite uncommon manifestations of M. pneumoniae disease. Reports on unusual courses of the disease have also accumulated, including cases of severe respiratory symptoms, sometimes seen in patients with underlying disease or with a concomitant viral infection. Serious extrapulmonary manifestations have been common in fatal cases of M. pneumoniae disease. Some observations and experimental data on these manifestations and on the possible pathogenic mechanisms are dealt with. The conclusion is that such mechanisms are still largely unknown.     

Mycoplasma pneumoniae Infection in the United Kingdom—1967-73

A widespread epidemic of Mycoplasma pneumoniae infection in the United Kingdom occurred over a 30-month period in 1970-72. A small epidemic may also have occurred in 1967-68. Though the incidence of M. pneumoniae infection is known to change from year to year in small communities, a varying epidemicity in the population of a country has not previously been demonstrated.As expected, lower respiratory tract infection was the most common manifestation of infection; and the highest attack rates were in children aged 5-9 years. Elderly persons appear to be affected uncommonly.     

儿童哮喘与肺炎支原体感染关系的探讨

目的:探讨儿童哮喘发作与肺炎支原体(MP)感染之间的关系,并分析合并MP感染的患儿的临床表现。方法:将79例2-14岁急性哮喘发作的患儿依据病史分做两组:第一次哮喘发作的35人(始发哮喘组),已经有哮喘病史的44人(复发哮喘组)。采用被动冷凝集法检测两组患儿肺炎支原体抗体(MP-IgM)。结果:始发哮喘组和复发哮喘组分别有16例(45.7%)和10例(22.7%)患儿MP-IgM阳性(P0.05)。始发哮喘组与复发哮喘组MP-IgM阳性的患儿发热和肺部啰音发生率明显高于MP-IgM阴性的患儿(P0.05),血清IgE水平也明显高于MP-IgM阴性的患儿(P0.05)。结论:MP感染与儿童哮喘发作关系密切,合并MP感染的哮喘患儿发热或肺部啰音发生率明显高于未合并MP感染的哮喘患儿。     

Cytokines in Mycoplasma pneumoniae infections

Mycoplasma pneumoniae (M. pneumoniae) is one of the smallest free-living bacteria known. Along with other unique characteristics of this genus, it lacks the typical peptidoglycan cell wall of most eubacteria. Best known for causing tracheobronchitis and atypical pneumonia in humans, this pathogen also causes a number of extrapulmonary syndromes such as meningitis/encephalitis and arthritis. Recent studies also suggest that infection may be associated with chronic conditions such as asthma. Although the mechanisms of M. pneumoniae pathogenesis remain to be elucidated, one important component of M. pneumoniae infections is the induction of proinflammatory and other cytokines in both acute and chronic conditions. In this review, we survey the induction of cytokines by M. pneumoniae in different model systems, and we discuss the possible role of induced cytokines in M. pneumoniae pathogenesis.     

Detection of Mycoplasma pneumoniae and Chlamydophila pneumoniae in patients with community acquired pneumonia

A total of 292 patients with pneumonia confirmed by clinical, roentgenological and laboratory methods, admitted to the hospital from closed communities during the one year period, were examined. The sputa of patients with pneumonia in the acute stage were studied in the polymerase chain reaction (PCR). The predominence of M. pneumoniae and C. pneumoniae causualties in autumn and winter period was established. The monitoring of atypical infective agents with the use of the PCR techniques gives evidence for conclusion on their ever growing role in the etiological structure of community acquired pneumonia in groups of closely interacting young people.     

探讨接种时间和剂量对小鼠肺炎支原体肺炎模型建立的影响

目的 用不同时间和剂量建立BALB/c小鼠的肺炎支原体肺部感染模型,探索小鼠急性肺炎支原体感染的过程.方法 BALB/c小鼠随机分为Ⅰ、Ⅱ两组,Ⅰ组在0、1、2 d滴鼻接种肺炎支原体菌液3次,Ⅱ组在0 d滴鼻接种小剂量肺炎支原体菌液1次后于8、9 d再接种和Ⅰ组相同的肺炎支原体菌液2次,均设立不同剂量、批次的生理盐水对照组.全部实验动物在3～18 d内分批处死.所有小鼠均取肺组织做病理切片.以组织病理学评分来确定小鼠的肺部炎症反应程度.取肺组织匀浆及肺泡灌洗液(BALF)进行肺炎支原体培养做病原学检测.结果 接种后实验动物全部存活无死亡.实验组动物均出现不同程度的肺炎支原体肺炎样病理改变,组织病理学评分为1.5～14.3分,分别于第5、6天和第11天达到最高,平均分为4.9分;Ⅰ组实验组动物多呈轻、中度改变,Ⅱ组实验组动物多呈中、重度改变.所有实验组动物肺组织匀浆及BALF的肺炎支原体培养在接种后1月内先后出现阳性结果.对照组动物未出现明显肺部炎症改变,组织病理学评分为0～1分,肺炎支原体培养为阴性.结论 成功建立BALB/c小鼠的肺部肺炎支原体感染模型;组织病理学评分方法可用以评价肺部炎症反应的严重程度;不同接种时间和剂量所致的病变程度不同.     

Serum immunoglobulin in Mycoplasma pneumoniae infection

The dynamics and nature of serum antibodies in experimental and natural M. pneumoniae infection have been studied. The synthesis of specific IgM, IgA and IgG has been found to occur in the course of infection. During repeated M. pneumoniae infection in guinea pigs, as well as in cases of acute and chronic mycoplasmal pneumonia in humans (at the acute period of the disease), the prevalence of the synthesis of specific IgM is observed. At the acute period of the disease a rise in the quantitative levels of IgM and IgG occurs in patients. High titers of specific IgM (1:32 and greater) determined at the acute period of the disease can serve as the diagnostic criterion of the mycoplasmal etiology of pneumonia.     

Mycoplasma pneumoniae DNA gyrase genes

We have identified a clone from a λEMBL3 library containing a 19kb insert of Mycoplasma pneumoniae DNA which includes the genes that encode both subunits of DNA gyrase. The gyrB gene and the 5’end of the gyrA gene have been subcloned into M13. The gryB gene is 1953bp in length and overlaps the gryA gene by a single base. The nucleotide sequence of these subclones has significant homology to previously reported gyrase genes. In terms of the size of gyrB gene and its proximity to the gyrA gene, M. pneumoniae is more similar to Bacillus subtilis than to Escherichia coli.     

Ultrastructural Features of Mycoplasma pneumoniae

The ultrastructure of Mycoplasma pneumoniae cultivated in broth on glass and plastic surfaces was studied by scanning and transmission electron microscopy. The organisms grew as filaments, which by over-crossing eventually formed a dense network on the surface and in colonies composed mainly of rounded and elongated forms. The filaments were usually thinner at the ends and terminated with a knob-like structure. Some filaments possessed short ramifications which also ended with a knob, and others showed constrictions. Sectioned organisms were seen to contain ribosome-like structures. Many organisms had a specialized structure at their thinner end, which consisted of a dense rod surrounded by electron-lucent cytoplasm and ending with a platelike thickening.     

Neonatal Streptococcus pneumoniae Infection May Aggravate Adulthood Allergic Airways Disease in Association with IL-17A

Epidemiologic studies have demonstrated that some bacteria colonization or infections in early-life increased the risk for subsequent asthma development. However, little is known about the mechanisms by which early-life bacterial infection increases this risk. The aim of this study was to investigate the effect of neonatal Streptococcus pneumoniae infection on the development of adulthood asthma, and to explore the possible mechanism. A non-lethal S. pneumoniae lung infection was established by intranasal inoculation of neonatal (1-week-old) female mice with D39. Mice were sensitized and challenged with ovalbumin in adulthood to induce allergic airways disease (AAD). Twenty-four hours later, the lungs and bronchoalveolar lavage fluid (BALF) were collected to assess AAD. Neonatal S. pneumoniae infection exacerbated adulthood hallmark features of AAD, with enhanced airway hyperresponsiveness and increased neutrophil recruitment into the airways, increased Th17 cells and interleukin (IL)-17A productions. Depletion of IL-17A by i.p. injection of a neutralizing monoclonal antibody reduced neutrophil recruitment into the airways, alleviated airway inflammation and decreased airway hyperresponsiveness. Furthermore, IL-17A depletion partially restored levels of inteferon-γ, but had no effect on the release of IL-5 or IL-13. Our data suggest that neonatal S. pneumoniae infection may promote the development of adulthood asthma in association with increased IL-17A production.