Legionella Pneumophila Pneumonia Research Articles

Pneumonia due to Legionella pneumophila and pneumococcal pneumonia: similarities and differences on presentation

We compared clinical, radiological and laboratory data from 32 cases of community-acquired pneumonia due to Legionella pneumophila, with 37 cases of pneumococcal pneumonia (PP). This study revealed few clinical differences between the two types of pneumonia: in our experience Legionnaire's disease presents like a "typical" bacterial pneumonia. Given the difficulty of making a diagnosis on clinical data alone, we propose early aetiological diagnostic measures and recommend that the choice of initial treatment be based not only on the features at the time of presentation, but also on a consideration of the epidemiology of different types of pneumonia in a given area.

Immunologic diversity among serogroup 1 Legionella pneumophila urinary antigens demonstrated by monoclonal antibody enzyme-linked immunosorbent assays

We tested urine specimens from 222 patients with serogroup 1 Legionella pneumophila pneumonia in two enzyme-linked immunosorbent assays (ELISAs) which used different monoclonal antibodies (A and B) as detector antibodies. Of 171 specimens which contained enough antigen to be detected in the ELISAs, 169 reacted in only one of the two assays. A total of 25 patients whose infections were acquired in any of three Indianapolis hospitals excreted antigen reactive with monoclonal antibody B, but 18 patients who were treated for infections acquired elsewhere reacted with monoclonal antibody A. The urinary antigen ELISA reactivity patterns correlated with the reactivity patterns of L. pneumophila isolates when a separate panel of seven monoclonal antibodies was used. The isolate patterns, in turn, correlated well with environmental isolate patterns from two of the hospitals with nosocomial cases. We conclude that at least two different epitopes exist on the antigen molecules in urine from patients with serogroup 1 L. pneumophila pneumonia and that the subtyping of urinary antigens can be useful epidemiologically.

Comparison of ciprofloxacin and rifampicin in experimental Legionella pneumophila pneumonia : Harlichek D, Pohold D, Saravolatz L: J Antimicrob Chemother 20:875–881, 1987

Comparison of ciprofloxacin and rifampicin in experimental Legionella pneumophila pneumonia : Harlichek D, Pohold D, Saravolatz L: J Antimicrob Chemother 20:875–881, 1987

Development and evaluation of diagnostic radiometric assays for serogroup 4 L. pneumophila urinary antigens.

We previously reported that 80% of patients with serogroup 1 Legionella pneumophila pneumonia excrete detectable quantities of specific antigens in their urine. The purpose of this study was to determine whether specific antigens can be detected in urine from patients with serogroup 4 L. pneumophila pneumonia. Antisera were prepared in 15 rabbits and used to set up 25 solid-phase radioimmunoassays. The best of these assays detected specific antigens in urine from 4 of 5 patients with culture-proven serogroup 4 infections and from 1 of 2 patients with culture-proven serogroup 10 infections. None of 100 control specimens was positive in the assays. The antigens from serogroup 4 and 10 infections behaved differently in the assays, suggesting that they are not identical molecules. This study demonstrates that it is possible to detect specific antigens in the urine of patients with serogroup 4 L. pneumophila pneumonia. This may be a useful method for diagnosing these infections rapidly.

Antigen detection for the rapid diagnosis of mycoplasma and legionella pneumonia

Immunologic attempts to detect mycoplasma antigens in fluids of infected patients have been rare and largely unsuccessful. Nucleic acid hybridization procedures appear promising on the basis of successes in detecting mycoplasmal contamination of tissue culture cells; results of attempts to apply these techniques to human infections have not been reported. Antigens can be detected in the urine of about 80% of patients with serogroup 1 Legionella pneumophila pneumonia and of some patients with serogroup 4 Legionella pneumophila and Legionella dumoffii pneumonia. The specificity of these assays is greater than 99%. In a test population in which the prevalence of Legionella pneumophila was 4%, the posterior probabilities of positive and negative results of tests for antigen were 86.5% and 99.3%, respectively. Antigen is detectable within the first 3 days of illness approximately as often as at later periods, and antigen may remain detectable for a few days to 1 yr after successful therapy. Antigen is detectable in serum, but the concentrations are considerably lower than in urine. Combining urinary antigen detection with direct fluorescent antibody examination of secretions increases the rapid diagnostic yield by 10%-20%. Monoclonal antibody studies demonstrate that subgroup specificities are present among the serogroup 1 urinary antigens. Radiometric and enzyme immunoassays detect antigen in equal proportions of patients. Latex agglutination results are positive in about 80% of those cases positive by the other methods.

Legionella pneumophila Wound Infection

LEGIONELLA pneumophila pneumonia was first recognized after the outbreak that followed the 1976 convention of the Pennsylvania Department of the American Legion in Philadelphia. 1 After the recognition of L pneumophila in causing pneumonia, a respiratory illness without pneumonia termed Pontiac fever was shown to be caused by the same agent. 2 Later, L pneumophila was demonstrated in tissues other than the lungs of patients who had pulmonary infiltrates, a finding that suggested hematogenous dissemination. 3 Vascular access sites in patients undergoing renal dialysis may also be infected. 4 From a perirectal abscess in one patient, L pneumophila and anaerobes were isolated. 5 We describe a patient without pneumonia from whom cultures of an open wound showed growth of L pneumophila and Pseudomonas aeruginosa . Apparently the L pneumophila was acquired by the patient from water in a Hubbard tank in which he was receiving daily rehabilitation. Routine disinfection of the

The kinetics of early inflammatory events during experimental pneumonia due to Legionella pneumophila in guinea pigs.

An animal model of Legionella pneumophila pneumonia was developed to study aerosol infection, pathogenesis, and pulmonary host defense mechanisms. Guinea pigs were exposed in an inhalation facility that limited the aerosol of L pneumophila to the snout. Bronchoalveolar lavage was used to sample airspace cells, secretions, and bacteria during developing infection in 79 exposed animals and 13 uninfected controls. An influx of polymorphonuclear neutrophils followed exponential bacterial growth during the initial three days of infection and coincided with limitation of the increase in bacteria recovered. A macrophage influx occurred at three to five days. Bacteria were eliminated from the lung by 11 days after exposure. Albumin in lavage fluid peaked at two days. Most viable L pneumophila organisms were associated with alveolar macrophages, whereas most of the bacteria associated with polymorphonuclear neutrophils were nonviable. Recruited, and possibly immune, defenses appear to be required for successful resolution of legionella pneumonia.

Proteins and Antibody in Lavage Fluid of Guinea Pigs with Legionella pneumophila Pneumonia

Guinea pigs were infected in an inhalation facility that limited an aerosol of L. pneumophila to the snout, as previously reported in detail ( Davis et al., 1982). Individual animals were sacrificed for study either immediately after exposure, at 16 hours, at days one through seven, or at 11 days. Bronchoalveolar lavage was carried out to obtain fluid to study the following: total protein, albumin and immunoglobulin G (IgG) concentrations, and the titer of antibody to L. pneumophila. Antibody also was measured in serum obtained at the time of sacrifice. Concentrations of total protein, albumin, and IgG in lavage fluids peaked 2 days after exposure and correlated with the appearance of maximal numbers of polymorphonuclear cells in the lung. Presumably, this increased protein resulted from exudation of serum across the alveolar-capillary membrane, which loses its integrity secondary to pneumonia. However, the ratio of IgG/albumin was elevated in animals studied 11 days after exposure even though the concentration of albumin was normal by this time. One possible explanation for this observation is that IgG was being produced in the lung. Antibody in lavage fluid was detected 7, and 11 days post-exposure, and might be important in the recovery of guinea pigs from this infection.

Simultaneous infection with Legionella pneumophila and Pittsburgh pneumonia agent. Clinical features and epidemiologic implications : Muder RR, Yu VL, Vickers RM, Rihs J, Shonnard J: Am J Med 1983; 74: 609–614

Simultaneous infection with Legionella pneumophila and Pittsburgh pneumonia agent. Clinical features and epidemiologic implications : Muder RR, Yu VL, Vickers RM, Rihs J, Shonnard J: Am J Med 1983; 74: 609–614

Simultaneous infection with Legionella pneumophila and Pittsburgh pneumonia agent: Clinical features and epidemiologic implications

Nosocomial pneumonia caused simultaneously by two organisms, Legionella pneumophila and the Pittsburgh pneumonia agent, was documented in seven patients in one Institution. In all seven cases, both organisms were demonstrated by isolation from culture or visualization by direct immunofluorescence. Four patients died as a result of pneumonia, including two who received erythromycin therapy. The hospital water distribution system appeared to be the reservoir for both L. pneumophila and Pittsburgh pneumonia agent. These seven cases constituted 26.9 percent and 17.9 percent of the cases of Pittsburgh pneumonia agent and Legionnaires' disease, respectively, at one institution. Given this relatively high incidence of dual infection, it is likely that the mode of transmission for both organisms is identical. Dual infection may account for some cases of antibody response to more than one Legionella species. Historical parallels of the discovery of L. pneumophila and Pittsburgh pneumoniaagent are reviewed.