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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight strains of Chlamydia psittaci isolated from swine with pneumonia, pleuritis, pericarditis, and enteritis were characterized through analysis of the major outer membrane protein gene ompA by a two-step polymerase chain reaction, by their interactions with cells in culture, and by the morphologic features and ultrastructure of intracellular inclusions. Amplified chlamydial ompA DNA fragments were differentiated by restriction endonuclease digestion. Chlamydial isolates were separated into 2 types on the basis of ompA restriction fragment length polymorphism. Strains of type L71 had finely granular inclusions, whereas those of type 1710S contained pleomorphic reticulate bodies (RB) in the inclusions, which are characteristic of aberrant chlamydial developmental forms. Chlamydial types L71 and 1710S required centrifuge-assisted inoculation for efficient infection of cell cultures. Cultivation in cell culture medium containing cycloheximide increased the numbers of chlamydial inclusions about 1.5-fold. These strains formed few elementary bodies in yolk sac cells of chicken embryos. Ultrastructurally, unique doublet RB were observed, particularly in strains of the ompA type L71. These doublets consisted of 2 RB, bounded by a cytoplasmic membrane, contained within a common cell wall and an extended periplasmic space. Ultrastructural examination of strains of the ompA type 1710S confirmed the aberrant chlamydial developmental forms, but evidence of viral infection of the RB as a cause of these aberrant forms was not found. The strain S45 isolated from intestinal sites of swine was a trachoma restriction fragment length polymorphism type. With the mouse biotype, it represented the second isolate from animals of Chlamydia trachomatis.
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PMID:Biological properties and genetic analysis of the ompA locus in chlamydiae isolated from swine. 135 14

An amplified enzyme immunoassay (IDEIA III: Dako Diagnostics Ltd) for detecting genus-specific chlamydia antigen was evaluated prospectively on 286 respiratory specimens from 275 patients presenting with community-acquired pneumonia or persistent chest infection. Nineteen patients had evidence of recent chlamydial infection, having two or more positive sputum or serological markers. Sputa from two other patients were ELISA-positive in the absence of other positive criteria and were regarded as false-positive results. When compared with a direct immunofluorescence test for chlamydial elementary bodies (EBs) using a genus-specific monoclonal antibody, the ELISA gave a positive predictive value of 91% and a negative predictive value of 99%. Non-specific problems with a wide variety of other micro-organisms isolated from the sputa were not encountered. Attempts to differentiate between Chlamydia psittaci, Chlamydia pneumoniae and Chlamydia trachomatis using genus-specific lipopolysaccharide reactive--and species-specific major outer membrane protein--monoclonal antibodies were encouraging and results were substantiated, in most patients, by the species-specific serological assays of the whole-cell-inclusion immunofluorescence or micro-immunofluorescence assays. The study demonstrated that antigen detection techniques offer scope for routine laboratories to diagnose chlamydial respiratory infections rapidly and reliably and may enable differentiation to species level. Although immunofluorescence offers marginally greater sensitivity and specificity when compared with ELISA, the latter is less subjective and less demanding. Sixty-eight per cent of these infections would have remained undiagnosed despite the general availability of ELISA tests.
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PMID:The differentiation of Chlamydia species by antigen detection in sputum specimens from patients with community-acquired acute respiratory infections. 152 42

The rapid development of biotechnological methods provides the potential of dissecting the molecular structure of microorganisms. In this review the molecular biology of chlamydia is described. The genus Chlamydia contains three species C. trachomatis, C. psittaci, and C. pneumonia which all are important human pathogens. Chlamydia is obligate intracellular bacteria with a unique biphasic life cycle. The extracellularly chlamydial elementary bodies (EB) are small, metabolic inactive, infectious particles with a tight outer cell membrane. After internalization into host cells the chlamydial structure changes, they transform to reticulated bodies (RB) which become larger, metabolically active, and start to replicate. Fourtysix hrs post infection RB reorganizes to EB followed by burst of the inclusion. The structure of the EB outer membrane differs from the membrane of gram-negative bacteria since it is highly cross-linked by S-S bridges. There are, however, also similarities to gram-negative cell walls. The chlamydial major outer membrane protein, Omp1, forms pores and is closely associated with lipopolysaccharide, LPS. LPS, however, is more loosely associated with Omp1 than in other gram negative bacteria since incubation of EB with antibodies against LPS will liberate it from the chlamydial surface. Therefore the surface localized LPS may be important for chlamydial survival. OMP1 varies between the different serovar of C. trachomatis. Several very conserved regions are separated by variable domains. The variable domains are very antigenic and are localized at the surface of EB. After chlamydial internalization into the host cell transition to RB starts. Some of the early proteins are DnaK-like and groEL-like heat-shock proteins. The chlamydial DnaK-like protein is very antigenic. Patient serum samples will recognize the chlamydial DnaK-like protein. From the determined DNA sequence the amino acid sequence was determined. It was 57% homologous to the Eschrichia coli DnaK protein. Also the GroEL-like protein is antigenic and very conserved. Factors of importance for pathogenicity of chlamydia have not yet been found. The adhesin(s) is unknown, and no factor of importance for the inhibition of fusion between phagosome and host cell lysosomes has been described. A protein similar to the mip gene product of Legionella pneumofila may be a possible candidate for a pathogenicity factor. Diagnosis of C. trachomatis infections has been done by chlamydia cultivation in tissue culture cells, by immunofluorescence and by ELISA. A new method based on the polymerase chain reaction (PCR) has been developed. As primers sequences from the common plasmid were used. This method has high sensitivity and specificity and does not require live chlamydia.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The molecular biology and diagnostics of Chlamydia trachomatis. 152 83

Chlamydia pecorum sp. nov. is proposed as the fourth species of the genus Chlamydia on the basis of the results of a genetic analysis of Chlamydia strains that were isolated from cattle and sheep which had various diseases, including sporadic encephalitis, infectious polyarthritis, pneumonia, and diarrhea. The levels of DNA-DNA homology between C. pecorum and strains of C. psittaci, Chlamydia pneumoniae, and Chlamydia trachomatis were less than 10%. Several DNA probes were used to identify C. pecorum. The C. pecorum strains were distinguished from C. psittaci strains by the results of immunological assays, including an immunofluorescence antibody assay performed with monoclonal antibodies and an immunoblot analysis of the immunological specificity of the major outer membrane protein. Species identification was based on results obtained from DNA analyses and serology. The type strain of C. pecorum is strain ATCC VR628.
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PMID:Proposal of Chlamydia pecorum sp. nov. for Chlamydia strains derived from ruminants. 158 Nov 91

Nonencapsulated Haemophilus influenzae cause mainly respiratory tract infections, including otitis, sinusitis, and pneumonia. These infections may become chronic or recurrent in patients with bronchitis or otitis. Patients are usually infected with one strain at a time. During recurrent otitis, H. influenzae isolates have an outer membrane protein composition different from that seen during earlier episodes. In chronic bronchitis, H. influenzae strains persist for up to 1 year. In addition, isolates with different outer membrane protein compositions have been obtained that are antigenic variants of previous isolates. The variations occur in outer membrane protein b,c (P2), d (P5), or both. The variable parts are immunodominant, and antibodies to these parts are bactericidal. Cross-reactive bactericidal antibodies to outer membrane proteins have been elicited in immunized animals. These data indicate that natural immunity to nonencapsulated H. influenzae is mainly strain-specific but also that biologically active cross-reactive antibodies can be elicited by immunization.
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PMID:Epidemiology and prevention of respiratory tract infections due to nonencapsulated Haemophilus influenzae. 158 58

Three monoclonal antibodies (MAbs), E4, L1-4, and L1-24, to the major outer membrane protein (MOMP) of Chlamydia trachomatis were identified that neutralized in vitro the infectivity of members of the B- and C-related complex as well as the mouse pneumonitis strain. MAbs L1-4, L1-24, and E4 gave a strong signal in an indirect immunofluorescence assay and/or Western immunoblot with all serovars of the lymphogranuloma venereum and trachoma biovars and a weak signal with the mouse biovar. In addition, C. psittaci and C. pneumoniae were also weakly recognized by MAbs L1-4 and L1-24. As determined by the technique of pneumoniae were also weakly recognized by MAbs L1-4 and L1-24. As determined by by the technique of overlapping peptides, all three MAbs showed reactivity to variable domain (VD) IV of MOMP. While all three MAbs had different recognition patterns, all strongly bound to the peptides TLNPTI and LNPTIA within the species-conserved region of VD IV. MAb E4 also recognized the peptide SATAIF in the subspecies region of VD IV. Peptides corresponding to VD IV of MOMP were synthesized and used in competitive inhibition experiments to determine the functional location of the epitope recognized by these three MAbs. Both the serological and neutralizing activities of MAb E4 were inhibited by the peptides ATAIFDTTTLNPTIAG and FDTTTLNPTIAG; however, none of the peptides made to the VD IV region blocked the neutralizing activity of MAbs L1-4 and L1-24. Therefore, the neutralizable domain of the epitope recognized by MAb E4 is contiguous and may be an important candidate for inclusion in a subunit vaccine.
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PMID:Functional and structural mapping of Chlamydia trachomatis species-specific major outer membrane protein epitopes by use of neutralizing monoclonal antibodies. 171 70

The gene encoding the major outer membrane protein of the Chlamydia trachomatis mouse pneumonitis biovar was sequenced and the amino acid sequence deduced. The primary structure of this protein is similar to that of the lymphogranuloma venereum and trachoma biovars in that it consists of four variable domains interspersed with five constant domains. This protein may be an ideal candidate for a vaccine in chlamydia-infected mouse experimental models.
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PMID:Sequence of the gene encoding the major outer membrane protein of the mouse pneumonitis biovar of Chlamydia trachomatis. 193 36

An immunodominant Haemophilus somnus outer membrane protein with an apparent molecular mass of 40 kDa on Western blots (immunoblots) of gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels was characterized because a monospecific antibody against this antigen was protective. This monospecific antibody was used for immunoaffinity purification of the antigen. The immunoaffinity-purified antigen reacted with a polyclonal antibody to the 40-kDa antigen but not with a monoclonal antibody (3G9) which reacted with the 40-kDa antigen in gradient gels. On 8 or 10% gels, the approximately 40-kDa antigen was resolved as two bands, a 40-kDa band which reacted with the protective monospecific polyclonal antibody (p40) and a band of lower molecular mass which reacted with monoclonal antibody 3G9. The latter antigen was designated p39. Both antigens were conserved in all H. somnus isolates tested. The specific antibodies were also used to detect cross-reacting antigens in other gram-negative bacteria. Antibody to p40 reacted with proteins of 55 to 28 kDa, with the greatest intensity shown among proteins from other members of the family Pasteurellaceae. Antibody to p40 was reduced by absorption with live H. somnus or other members of the family Pasteurellaceae, so the antigen appears to be surface exposed. Antibody to p39 only cross-reacted with a broad band (38 to 40 kDa) in Haemophilus agni. Since H. agni is not a bovine pathogen and since convalescent-phase serum from H. somnus-infected animals did recognize p39, the latter may be a good immunodiagnostic antigen, if the lack of cross-reactivity with antigens in other gram-negative bacteria is confirmed with a polyclonal antibody to p39. The cross-reactivity of antiserum to p40 with antigens of members of the family Pasteurellaceae and the ability of this antiserum to protect against H. somnus pneumonia indicate that p40 may be a useful vaccine antigen for H. somnus disease and perhaps even diseases caused by other members of the family Pasteurellaceae.
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PMID:Characterization of immunodominant surface antigens of Haemophilus somnus. 193 91

Monoclonal antibodies (MAbs) directed against the 37.5-kDa outer membrane protein were produced by fusing myeloma cells with spleen cells obtained from mice immunized with a pathogenic strain of Pasteurella multocida isolated from a rabbit. Desirable MAbs were selected by enzyme-linked immunosorbent assay, whole-cell radioimmunoprecipitation (WC-RIP), and Western blot (immunoblot) analysis. WC-RIP and Western blot analyses, using MAb 1608 adsorbed with intact P. multocida cells and the eluted MAb, demonstrated that the antigen recognized by this MAb is exposed on the cell surface, is antibody accessible, and has an estimated molecular mass of 37.5 kDa. Treatment of outer membrane vesicles of P. multocida with proteinase K totally abrogated the MAb 1608 activity, indicating that this MAb binds to a protein antigenic determinant. Furthermore, MAb 1608 was nonreactive to purified lipopolysaccharide in Western blot analysis. Passive transfer studies showed that nine rabbits inoculated intranasally with MAb 1608 and homologously challenged intranasally had significantly reduced mortality, severity of pneumonia, prevalence of P. multocida colonization in nonrespiratory organs, and numbers of P. multocida in nasal cavities compared with the controls. Furthermore, the number of P. multocida in lungs was reduced 84,750-fold. Similarly, passive transfer experiments indicated that MAb 1608 protected mice against homologous and heterologous challenges with P. multocida strains bearing the antigenic determinant recognized by MAb 1608. However, no protection was afforded by MAb 1608 when mice were challenged with a P. multocida strain lacking the antigenic determinant recognized by MAb 1608. This study establishes that the 37.5-kDa outer membrane protein is the target for a protective MAb.
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PMID:A monoclonal antibody against a Pasteurella multocida outer membrane protein protects rabbits and mice against pasteurellosis. 198 31

Haemophilus influenzae is a gram-negative rod, causing severe infections in childhood, including meningitis, sepsis, epiglottits, pneumonia and otitis. Most of the invasive infections are due to serotype b. Since ampicillin-resistance is increasing, modern cephalosporines like cefotaxime and ceftriaxone are the antibiotics of choice in severe disease. Bacterial meningitis due to Haemophilus influenzae and epiglottitis are both still life-threatening diseases with a lethality of 5% to 25%, and there are severe sequelae in 35% of meningitis cases. Efforts have been made to develop efficacious vaccines. While immunogenicity of type b polysaccharide was low in the high-risk age (below 18 months), conjugated vaccines with either diphtheria-toxoid or Neisseria meningitis outer membrane protein and the Hib polysaccharide were found to be strongly immunogenic even in the first months of life. These vaccines show every few side-effects and can easily be combined with other immunizations such as DPT and DT. Thus, the incidence of invasive infections due to Haemophilus influenzae type b might decline in future.
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PMID:[Haemophilus influenzae type B. Disease and prevention]. 219 58


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