Antigenic structure of the polysaccharide capsule of Streptococcus pneumoniae strains isolated in Leningrad 1978-1984

The serotyping of 826 S. pneumoniae strains, isolated in conditionally diagnostic concentrations from the bronchial contents of patients with acute and chronic inflammatory pulmonary diseases during 1978-1984 in Leningrad, was made. The study revealed the prevalence of serotypes and groups 6, 23, 9, 3, 19, 15 and the undulant character of fluctuations in their annual occurrence. The specific proportion of the prevailing serotypes of S. pneumoniae among the cultures isolated from patients with acute pneumonia and acute bronchitis (6 and 19) was found to differ from that among S. pneumoniae strains isolated from patients with chronic bronchitis; in the latter patients serotypes 3 and 9 occurred more frequently (P less than 0.01).     

Etiology of acute pneumonia occurring against a background of influenza and other acute respiratory viral infections

The etiology of acute pneumonia (AP) was studied in 229 patients who had the disease simultaneously with influenza (106 patients), other viral and mycoplasmal infections (48 patients), and without concomitant acute viral infections (75 patients). The use of the quantitative microbiological method and the indirect immunofluorescence test with autostrains or Streptococcus pneumoniae strains of serotypes 2, 3, and 6, prevailing in Leningrad in patients with acute inflammatory diseases of the lungs, made it possible to find out the pneumococcal etiology of AP in 95% of patients irrespective of the presence of acute respiratory viral infections. The etiological role of opportunistic bacteria was revealed in 13 AP patients (5.7%); in 2 of them the causative agent of AP was Staphylococcus aureus and in 11, various species of Gram-negative enterobacteria. The latter were the cause of complications in 8 cases of pneumococcal pneumonia.     

Pneumococcal serotypes in children with acute and chronic inflammatory diseases of the lungs and in healthy children

The serotyping of 350 Streptococcus pneumoniae strains isolated from patients with acute and chronic diseases of the respiratory organs and from healthy children was carried out with the use of the agglutination test. 145 pleural fluid samples were tested for the presence of the pneumococcal antigen and its K-type. The prevailing pneumococcal serotypes were 6, 1, 19, 12 and 9 in acute pneumonia and 6, 19, 42, 3 and 12 in chronic pneumonia, including, respectively, 64.8% and 62% of all typed strains. Cases of pneumonia with complications in the form of pleuritis were mostly induced by serotypes 3, 1, 12 and 14, while in the destructive forms of pneumonia K-types 3, 14, 9 and 12 were isolated. Examinations of healthy pre-school children have shown 16.1% of them to be transitory pneumococcus carriers. Multiple biological examinations carried out during 1.5 years revealed that in this period 42.4% of the children were pneumococcus carriers.     

Streptococcus pneumoniae serotypes in children with acute pneumonia and pleurisy

The study of pneumococci of different serotypes, isolated from patients with acute pneumonia and pleuritis and from healthy children was carried out. Among the pneumococcal serotypes causing pneumonia and pleuritis in children serotypes 1, 6, 19, 14 and 3 were most widely spread and constituted 62.3% of all isolated pneumococci. In young children cases of acute pneumonia and pleuritis were more often induced by serotypes 6 and 14 and in older children, by serotypes 1 and 3. In patients with uncomplicated pneumonia and pleuritis differences in the detected serotypes of pneumococci were observed, and the disease course differed in severity. Serotypes 14, 3 and 3 induced destructive processes in the lungs more often than other serotypes. Monitoring of the sensitivity of pneumococci to antibiotics showed that most of the strains retained high sensitivity to penicillin and ampicillin. In most cases the detected resistant pneumococcal strains belonged to serogroup 19.     

Impact of Preceding Flu-Like Illness on the Serotype Distribution of Pneumococcal Pneumonia

Background

Even though the pathogenicity and invasiveness of pneumococcus largely depend on capsular types, the impact of serotypes on post-viral pneumococcal pneumonia is unknown.

Methods and Findings

This study was performed to evaluate the impact of capsular serotypes on the development of pneumococcal pneumonia after preceding respiratory viral infections. Patients with a diagnosis of pneumococcal pneumonia were identified. Pneumonia patients were divided into two groups (post-viral pneumococcal pneumonia versus primary pneumococcal pneumonia), and then their pneumococcal serotypes were compared. Nine hundred and nineteen patients with pneumococcal pneumonia were identified during the study period, including 327 (35.6%) cases with post-viral pneumococcal pneumonia and 592 (64.4%) cases with primary pneumococcal pneumonia. Overall, serotypes 3 and 19A were the most prevalent, followed by serotypes 19F, 6A, and 11A/11E. Although relatively uncommon (33 cases, 3.6%), infrequently colonizing invasive serotypes (4, 5, 7F/7A, 8, 9V/9A, 12F, and 18C) were significantly associated with preceding respiratory viral infections (69.7%, P<0.01). Multivariate analysis revealed several statistically significant risk factors for post-viral pneumococcal pneumonia: immunodeficiency (OR 1.66; 95% CI, 1.10–2.53), chronic lung diseases (OR 1.43; 95% CI, 1.09–1.93) and ICI serotypes (OR 4.66; 95% CI, 2.07–10.47).

Conclusions

Infrequently colonizing invasive serotypes would be more likely to cause pneumococcal pneumonia after preceding respiratory viral illness, particularly in patients with immunodeficiency or chronic lung diseases.     

Streptococcus pneumoniae serotypes in children with chronic inflammatory diseases of the respiratory organs

During the 7-year period of observation (1982-1988) the serotypes of 276 pneumococcal strains isolated from children with chronic bronchopulmonary diseases were studied. Among the serotypes of pneumococci under study, serotypes 6, 19 and 15 held the leading place and included a half of all typed pneumococci. Dynamic observation on the serotype composition of pneumococci revealed periodic fluctuations in the occurrence of some types/groups. The regional analysis of different serotypes of pneumococci showed the common occurrence of serogroups 6 and 19, as well as some regional features in the circulation of serotypes 6, 10, 3 and rarely occurring serotypes. The study revealed that any new exacerbation of the chronic bronchopulmonary process is caused by pneumococci of some other serotype. Pneumococcal strains, resistant (3.4%) and sensitive (1.8%) to penicillin, were detected; most of them belonged to serogroup 19.     

The indices of antipneumococcal immunity in children with chronic pneumonia

In 76 children with chronic pneumonia the levels of serum antibodies to pneumococcal capsular polysaccharide antigens (serotypes 1, 3, 6B, 8, 9N, 15F, 23F), O-polysaccharide and pneumococcal protein somatic antigens were determined by ELISA techniques. The study showed that in sick children the content of antipneumococcal antibodies in the blood increased with age. No correlation between the content of total immunoglobulins and that of antipneumococcal antibodies in the blood of the patients was established, but a sharp decrease in the concentration of antibodies was registered in a child with hypoglobulinemia. No increase in the level of antibodies to pneumococcal antigens was observed in cases of the exacerbation of Pneumococcus-induced inflammatory process in the lungs.     

Virulence of Streptococcus pneumoniae strains belonging to different serovars

The study of the virulence of 352 S. pneumoniae strains isolated from patients with inflammatory lung diseases revealed that their virulence depended, to a certain extent, on the state of the polysaccharide capsule of streptococci, as among 299 typed cultures 38.1% were virulent, while out of 53 nontypable strains of these bacteria only 8 strains (15.1%) proved to be highly pathogenic for white mice and all S. pneumoniae R-forms proved to be avirulent. All 11 S. pneumoniae strains under study belonging to serovars 1 and 2 and 87% of the cultures belonging to serovar 3, isolated from patients with inflammatory lung diseases in Leningrad, were highly virulent. The characteristic feature of S. pneumoniae cultures of other serotypes was their wide spectrum of pathogenicity. S. pneumoniae cultures isolated from the spinal fluid of patients with pneumococcal meningitis also differed in their pathogenicity levels but strains highly pathogenic for mice prevailed.     

Effect of vaccination against pneumococcal infection in children with type 1 diabetes mellitus

Vaccination with polysaccharide pneumococcal vaccine "Pneumo 23" (Sanofi Pasteur, France) was performed in 31 children with type 1 diabetes mellitus (DM1) as well as in 19 children with respiratory tract diseases (asthma, chronic pneumonia), which formed comparison group. Fourty-three unvaccinated children with DM1 were included in the control group. Dynamics of IgG levels to mixture of pneumococcal polysaccharides (PS) included in the vaccine as well as to PS of serotypes 3, 6B, 9N, 23F, and to cell wall polysaccharides of Streptococcus pneumoniae were assessed. Using ELISA method, significant increase of IgG levels to mixture of PS and to PS of pneumococcal serotype 3 was detected. Although intensity of immune response to vaccination in children with respiratory diseases was significantly higher compared to children with DM1 (mean geometric titer of antibodies, proportion of patients with high antibody titers, and with 4-fold seroconversion). Development of methods to strengthen immune response in children with DM1 vaccinated against pneumococcal infection is required.     

Proteomic analysis of exhaled breath condensate for diagnostics of respiratory system diseases

Study of proteomic composition of exhaled breath condensate (EBC) is a promising non-invasive method for diagnostics of respiratory system diseases in patients. In this study the EBC proteomic composition of 53 donors, including patients with different respiratory system diseases has been investigated. Cytoskeletal keratins type II (1, 2, 3, 4, 5, 6) and cytoskeletal keratins type I (9, 10, 14, 15, 16) were invariant for all samples. Analyzing the frequency of occurrence of proteins in different groups of examined patients, several categories of proteins have been recognized: proteins found in all pathologies (dermcidin, alpha-1- microglobulin, SHROOM3), proteins simultaneously found in two groups (CSTA, LCN1, JUP, PIP, TXN), and proteins specific for a particular group (PRDX1, annexin A1/A2). The EBC analysis by HPLC-MS/MS can be used for identification of potential protein markers specific for inflammatory pulmonary diseases of infective origin (pneumonia) as well as for non-infectious diseases such as chronic obstructive pulmonary disease (COPD).     

Problems in dissociating strains of Streptococcus pneumoniae

The processes of dissociation occurring under the influence of soluble starch and some substances with surface activity (Tween-80, cattle bile and sodium desoxycholate) in 4 pneumococcal strains (Nos. 204, 205, 1225, 1317) isolated from patients with acute and chronic inflammatory lung diseases have been studied in vitro. Stable pneumococcal R-forms have been obtained by treatment with 0.1% sodium desoxycholate and 0. 5% bile and subsequent selection. The colonies of pneumococcal R-forms are characterized by a large size, a rough surface, uneven edges and pronounced alpha-hemolysis. The features typical of the population of these cultures are the polymorphism of cell element, the formation of long diplococcal chains, the almost complete disappearance of the capsule, as well as the negative results of the slide agglutination test and Neufeld s test with "omni" and typing pneumococcal antisera. Besides, the pneumococcal R-forms thus obtained have proved to be resistant to optochine (6 micrograms/ml) and bile (10-20%) and to possess low virulence.     

Seromucoid Fraction Patterns of Individuals with Pneumonia or Leukemia

Chromatographic separations on DEAE cellulose have been carried out on the seromucoid fraction from forty-one normal individuals and twenty-three patients horpitalized with unilateral pneumococcal pneumonia. During the acute stages of their illness, all twenty-three patients showed a very marked difference in their seromucoid pattern as contrasted to the control group, both groups being comparable in age, sex, and race. As the patients recovered, their seromucoid patterns returned to that of the control group. Three patients with bilateral pneumococcal pneumonia showed seromucoid patterns similar to those of the twenty-three patients with unilateral pneumococcal pneumonia. Five individuals with viral pneumonia showed a seromucoid pattern similar to those observed in patients with pneumococcal pneumonia. The data suggested that the seromucoid pattern observed in pneumonia depended upon the stage of the disease of the patient, different patterns being observed during the acute, convalescent, and complete recovery stages. Each stage showed a characteristic pattern. The seromucoid pattern of seven patients with acute leukemia differed from that of the control groups and also differed from that observed in patients with pneumonia. Five individuals with chronic lymphocytic leukemia showed seromucoid patterns which could not be distinguished from those of the control group in spite of the fact that all showed clinical signs of disease at the time the blood sample was drawn for fractionation.     

Clinical picture of secondary pneumonia in our observations

Hundred sixty four patients with the secondary pneumonia were analysed. The secondary pneumonia amounted to 65.8% of all cases of pneumonia treated within several years. Patients' sex, age, clinical symptoms, X-ray findings, coexisting diseases, sequence of the symptoms and the rate of their disappearance were analysed. It was found that the secondary pneumonia is prevailing in males over 40 years of age and most frequently accompany cardiac failure and chronic unspecific respiratory diseases. It is characterized by slow onset and the lack of typical symptoms in the high percentage of patients. Radiological and clinical symptoms disappear more slowly. However, various ausculatory symptoms of pulmonary involvement often accompany the secondary pneumonia and are not directly related to the inflammatory lesion to the lungs.     

Virulence of Streptococcus pneumoniae serotype 6C in experimental otitis media

Increases in colonization with serotypes of Streptococcus pneumoniae not contained within the 7-valent pneumococcal conjugate vaccine (PCV) have been reported among children following introduction. Serotype 6C has emerged as prevalent in nasopharyngeal colonization and acute otitis media (AOM), though it is uncommonly recovered from children with invasive pneumococcal disease. Vaccine serotypes within PCV7 have been replaced by nonvaccine serotypes without significant changes in the overall carriage rate. We hypothesize 1) that serotypes vary in their ability to evade host defenses and establish AOM following colonization and 2) the observed reduction in pneumococcal otitis results from a reduced disease potential by some ‘replacement serotypes’. We compared the capacity of S. pneumoniae serotypes 6C and 19A to produce experimental otitis media (EOM) in a chinchilla model. The proportion of chinchillas that developed culture positive EOM and density of middle ear infection was evaluated. EOM was found in 28/82 (34%) ears challenged with 6C compared to 13/18(72.2%) with 19A [p = 0.0003]. When disease due to 6C did occur, it was characterized by low-density infection. Our findings demonstrate that challenge with serotype 6C results in EOM less frequently than 19A. These data support the need for greater knowledge regarding differences among serotypes to produce AOM.     

肺炎链球菌糖疫苗的研究进展

肺炎链球菌(Streptococcus pneumoniae)是引起多种疾病的主要病原体,包括侵袭性感染(如败血症和脑膜炎菌血症),以及更常见的粘膜部位感染(如肺炎、中耳炎和鼻窦炎).根据肺炎链球菌表面荚膜多糖结构的不同可以分成不同的血清型,至今已经鉴定出98种,其中有20种具有高毒力.为了预防肺炎链球菌感染,已研制出...     

The NLRP3 inflammasome is differentially activated by pneumolysin variants and contributes to host defense in pneumococcal pneumonia

Streptococcus pneumoniae is a leading cause of pneumonia, meningitis, and sepsis. Pneumococci can be divided into >90 serotypes that show differences in the pathogenicity and invasiveness. We tested the hypotheses that the innate immune inflammasome pathway is involved in fighting pneumococcal pneumonia and that some invasive pneumococcal types are not recognized by this pathway. We show that human and murine mononuclear cells responded to S. pneumoniae expressing hemolytic pneumolysin by producing IL-1β. This IL-1β production depended on the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome. Some serotype 1, serotype 8, and serotype 7F bacteria, which have previously been associated with increased invasiveness and with production of toxins with reduced hemolytic activity, or bacterial mutants lacking pneumolysin did not stimulate notable IL-1β production. We further found that NLRP3 was beneficial for mice during pneumonia caused by pneumococci expressing hemolytic pneumolysin and was involved in cytokine production and maintenance of the pulmonary microvascular barrier. Overall, the inflammasome pathway is protective in pneumonia caused by pneumococci expressing hemolytic toxin but is not activated by clinically important pneumococcal sequence types causing invasive disease. The study indicates that a virulence factor polymorphism may substantially affect the recognition of bacteria by the innate immune system.     

中性粒细胞胞外诱捕网与肺部炎症性疾病的关系

中性粒细胞募集/浸润是肺部炎症性疾病的特征性表现,是肺部抵抗病原微生物入侵的第一道防线,主要通过吞噬作用杀灭病原微生物.然而,新近的研究发现,中性粒细胞被刺激后可形成一种以DNA为骨架并镶嵌有大量活性蛋白质的网状物质——中性粒细胞胞外诱捕网(neutrophil extracellular traps,NETs),这种特殊形式的生物结构能捕获并杀灭病原微生物.尽管就NETs的生物学功能而言,其对肺部炎症性疾病应该是有益的,但是越来越多的研究表明,NETs对肺上皮细胞和内皮细胞均具有直接的细胞毒性作用,并可能促进肺部炎症性疾病的发生发展.为了系统地了解NETs与肺部相关炎症性疾病的关系,本综述首先简述了NETs的结构、功能和形成过程,然后分别叙述了NETs与哮喘、慢性阻塞性肺病、细菌性肺炎、肺结核、肺囊性纤维化、间质性肺疾病、流感病毒感染和急性肺损伤的关系.最后总结、展望了NETs在肺部炎症性疾病中的潜在研究方向和针对性治疗策略.     

Sex and inflammation in respiratory diseases: a clinical viewpoint

This review discusses sex differences in the prognosis of acute or chronic inflammatory diseases. The consequences of severe inflammation vary in relation to sex, depending on illness duration. In the majority of acute diseases, males present higher mortality rates, whereas continuous chronic inflammation associated with tissue damage is more deleterious in females. The recruitment of cells, along with its clinical expression, is more significant in females, as reflected by higher inflammatory markers. Given that estrogens or androgens are known to modulate inflammation, their different levels in males and females cannot account for the sexual dimorphism observed in humans and animals from birth to death with regard to inflammation. Numerous studies evaluated receptors, cytokine production, and clinical outcomes in both animals and humans, revealing that estrogens clearly modulate the immune response, but the results are contradictory and difficult to link to hormone concentrations. Even in prepubescent children, the presentation of acute pneumonia or chronic diseases mimics the adult pattern. Several genes located on the X chromosome have been shown to encode molecules involved in inflammation. Moreover, 10% to 15% of the genes from silenced X chromosome may escape inhibition. Females are also a mosaic of cells with genes from either paternal or maternal X chromosome. Therefore, polymorphism of X-linked genes would result in the presence of two cell populations with distinct regulatory arsenals, providing females with greater diversity to fight against infectious challenges, in comparison with the uniform cell populations in hemizygous males. The similarities observed between males and Turner syndrome patients using an endotoxin stimulation model support the difference in gene expression between monosomy and disomy for the X chromosome. Considering the enhanced inflammation in females, cytokine production may be assumed to be higher in females than males. Even if all results are not clear-cut, nonetheless, many studies have reported higher cytokine levels in both male humans and animals than in females. High IL-6 levels in males correlated with poorer prognosis and shorter longevity. A sound understanding of the basic regulatory mechanisms responsible for these gender differences may lead to new therapeutic targets.     

23-valent pneumococcal vaccine failure in a patient who developed pneumonia: a case report

We report a clinical failure of a pneumococcal vaccine in a patient who developed pneumococcal pneumonia. In 2008, an 85-year-old Italian woman was admitted to the Respiratory Disease Unit of a hospital in Southern Italy. The 23-valent pneumococcal vaccine had been administered to the patient 50 days earlier. The chest x-ray disclosed a right basal bronchopneumonic focus. Streptococcus Pneumoniae serotype 19A, a strain included in the 23-valent pneumococcal vaccine, was isolated from the sputum. There is a need for more efficacious conjugated vaccines covering the majority of the pneumococcal serotypes that cause serious illness in older children and adults worldwide.     

Etiology of pulmonary diseases in children in Khabarovsk Region

Microflora of upper respiratory tract in 658 children aged 1 month - 17 years hospitalized with acute pneumonia (AP), acute bronchitis (AB), recurrent obstructive bronchitis (ROB), malformation of lungs (ML) and broncho-alveolar dysplasia (BALD) were studied. Carriage rates of Streptococcus pneumoniae (up to 95%) and Haemophilus influenzae (up to 89%) in 240 children attending daycare centers and schools were determined. Etiology of infectious process was ascertained in 40% of cases. S. pneumoniae was isolated in 45% of acute cases (AP and AB) and in 25% of chronic cases (BALD). H. influenzae was isolated in 8 - 12% of acute cases and in 32% of chronic cases. In 23 - 29% of all cases of pulmonary pathology in children persistence of Enterococcus faecium was determined. There were 13 different serotypes among isolated pneumococci. In patients with pneumonia the rate of detection of S. pneumoniae and H. influenzae DNA fragments by PCR was significantly higher compared with rate of their isolation from sputum.