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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are alarming reports about high counts of Legionella and Pseudomonas in the aerosol of inhalation-rooms. We therefore investigated 14 institutions (6 kurhauses, 5 hospitals and 3 sanatoria for children) in Schleswig-Holstein, each of them at least five-fold. For that purpose the inhalant (seawater as a rule) was investigated for the total bacterial number and the number of Legionella. Cfu/m3 air were determined at the aerosol outlet and a qualitative search for Legionella was done in the piping. In addition bacterial numbers in the air at the breathing-levels of patients were measured in order to be able to assess health hazards by germs of other patients. Detected bacterial numbers (10(1) - > 10(4)) were basically subject to the handling of the equipment and the type of apparatus used. Predominantly Staphylococci and Bacilli were found and above all when the first row of investigations was carried out large numbers of Pseudomonas, Aeromonas and others occurred. Legionella could not be detected. As a whole the investigations showed that properly maintained room-inhalators pose no higher risk of infection. These facilities, however, might be contaminated at any time and there is a certain--even though comparatively low--risk of infection due to germs exhaled by other patients. Patients, which are predisposed to infections of the respiratory tract--f.i. patients suffering from mucoviscidosis or patients with lowered resistance--should therefore generally use single inhalators.
Zentralbl Hyg Umweltmed 1992 Dec
PMID:[The danger of infection in inhalation rooms]. 129 May 66

Six Legionella strains were characterized with the BIOLOG identification system. A specific metabolic pattern for the six Legionella strains was observed after 24 h. Several positive reactions were detected intermittently in all six strains tested. The possible application of the BIOLOG system for identification of Legionella spp. from environmental or clinical samples is discussed.
Lett Appl Microbiol 1990 Dec
PMID:Biochemical fingerprints of Legionella spp. by the BIOLOG system: presumptive identification of clinical and environmental isolates. 136 98

The interaction of interferon (IFN)-gamma, rat alveolar macrophages, and Legionella pneumophila was studied in vitro to define the effector cell potential of alveolar macrophages against an intracellular pathogen in a model in which the efficacy of IFN-gamma could be tested in vivo. Alveolar macrophages preincubated with IFN-gamma up-regulated Ia antigen and killed 0.5-4 logs of L. pneumophila over 4 days compared with 1-2 logs of bacterial growth in untreated cells. The bactericidal effect was dose dependent, evident over a wide range of bacterial inocula, and not suppressed by hydrocortisone. Preincubation with IFN-gamma was unnecessary and insufficient, as intracellular replication was reversed by exposure to IFN-gamma up to 48 h after infection, and neutralization of IFN-gamma after infection permitted bacterial growth. IFN-gamma thus converts alveolar macrophages from target cells to effector cells in host defense against L. pneumophila and may be of therapeutic benefit in legionellosis.
J Infect Dis 1992 Dec
PMID:Recombinant murine interferon-gamma reversibly activates rat alveolar macrophages to kill Legionella pneumophila. 143 Dec 53

Legionella pneumophila, the causative agent of Legionnaires' disease, is a facultative intracellular pathogen of alveolar macrophages. Although previous studies have demonstrated that specific antibody facilitates uptake of L. pneumophila by phagocytic cells, the role of complement has been unclear. Thus, we have examined the relative contributions of Fc gamma- and complement receptor-mediated adherence to guinea pig peritoneal macrophages, U937 human monocytic cells, and J774 mouse macrophage cells. Opsonization of L. pneumophila (Philadelphia 2) with polyclonal immunoglobulin G promoted maximum adherence to guinea pig macrophages. In contrast, incubation in the presence of 20% fresh nonimmune human serum from a single donor did not promote adherence. The results obtained with U937 and J774 cells paralleled those obtained with guinea pig macrophages. In the absence of specific antibody, opsonization with guinea pig complement did not enhance adherence of the Philadelphia 1, Philadelphia 2, or Knoxville strain. However, when complement was added to heat-inactivated, specific antiserum, a fourfold increase in the number of adherent organisms was observed. Blocking studies utilizing membrane receptor-specific monoclonal antibodies demonstrated that both Fc and complement receptors mediated adherence of organisms treated with complement in the presence of specific antibody. These results suggest that complement augments adherence of L. pneumophila only when acting in concert with specific antibody.
Infect Immun 1992 Dec
PMID:Adherence of Legionella pneumophila to guinea pig peritoneal macrophages, J774 mouse macrophages, and undifferentiated U937 human monocytes: role of Fc and complement receptors. 145 53

During in vitro encystation, Giardia lamblia expresses several stage-specific proteins which are recognized in immunoblots by antisera raised against antigens from three different pathogens. The antigens belong to two different families of conserved stress proteins: (i) HSP60 purified from Legionella pneumophila and recombinant HSP60 from Mycobacterium bovis BCG and (ii) recombinant HSP70 from Plasmodium falciparum.
Infect Immun 1992 Dec
PMID:Encystation of Giardia lamblia leads to expression of antigens recognized by antibodies against conserved heat shock proteins. 145 66

Important changes in the initial management of community-acquired pneumonia have been prompted by the discovery of new respiratory pathogens, the changing susceptibility of traditional pathogens to antimicrobial agents, and the introduction of new antimicrobial agents. Although the clinical presentation may suggest a specific pathogen, findings overlap too much to reliably distinguish the specific cause of the pneumonia on a clinical basis. Useful laboratory studies include Gram's stain and culture of sputum, blood culture, serologic studies, and new tests such as the urinary antigen test for Legionella pneumophila. Empirical antimicrobial treatment must take into consideration that 20% to 30% of cases of community-acquired pneumonia are due to atypical pathogens that are not susceptible to beta-lactam agents.
Postgrad Med 1992 Dec
PMID:Community-acquired pneumonia. The changing picture. 145 67

The role of nitric oxide (NO) radicals in killing the intracellular bacterial pathogen Legionella pneumophila (Lp) was examined in infected macrophages. Murine (RAW 264.7) and human (HL-60) cell monolayers were treated with 100 U/ml gamma-interferon (IFN) and cocultured with Lp in the presence and absence of NGMMA, a specific inhibitor of NO production. Viable Lp in IFN-treated RAW 264.7 cells decreased from 3.8 to 0.7 +/- 0.12 log CFU/ml after 24 h incubation, whereas in IFN+NGMMA-treated RAW 264.7 cells, viable Lp persisted at 2.2 +/- 0.2 log CFU/ml after 24 h. This increased survival corresponded with an inhibition of NO production (5.65 +/- 2.99 microM with NGMMA vs. 58.6 +/- 5.36 microM without NGMMA). Viable Lp were susceptible to killing, in a dose-dependent fashion, by 0, 2.5, and 5.0 mM sodium nitroprusside, a source of NO radicals. IFN-treated RAW 264.7 cells also had significantly decreased levels of intracellular iron (below assay limit) when compared to IFN+NGMMA-treated cells (72.0 +/- 0.78% of control). Normally permissive HL-60 cells treated with IFN were bacteriostatic rather than bactericidal, and NO production was not detected above background. Thus, NO radicals play a critical role in the bactericidal activity against Lp by IFN-treated RAW 264.7 cells, but the absence of NO production limits IFN-treated HL-60 cells to bacteriostasis.
J Leukoc Biol 1992 Dec
PMID:Killing of Legionella pneumophila by nitric oxide in gamma-interferon-activated macrophages. 146 34

Legionella often causes systemic manifestations. The clinical spectrum now includes cardiac legionellosis. The first case of myocarditis was reported by Gross in 1981. To date few additional cases have been described. Myocardial involvement might be more frequent than supposed in legionnaires' disease.
Int J Cardiol 1992 Dec
PMID:Myocarditis: a rare complication during Legionella infection. 146 29

The in vitro activities of temafloxacin, ciprofloxacin, and ofloxacin against gram-negative bacteria are compared. The 90% minimal inhibitory concentrations (MIC90s) of temafloxacin for respiratory pathogens such as Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitidis, Bordetella pertussis, and Legionella pneumophila are less than or equal to 0.06 micrograms/mL. Temafloxacin is also active against bacterial agents of sexually transmitted diseases, including Neisseria gonorrhoeae (MIC90 less than or equal to 0.015 micrograms/mL) and Chlamydia trachomatis (MIC90 0.25 micrograms/mL). For strains of Enterobacteriaceae, Campylobacter, Vibrio, Aeromonas, and Acinetobacter, temafloxacin is generally inhibitory at less than or equal to 0.5 micrograms/mL. The MIC90 of temafloxacin for Pseudomonas aeruginosa is higher than that of ciprofloxacin, approximately 4 micrograms/mL versus 0.5 micrograms/mL. This activity, combined with its pharmacokinetic characteristics, should make temafloxacin an effective antimicrobial agent against infections caused by gram-negative bacteria.
Am J Med 1991 Dec 30
PMID:In vitro activity of temafloxacin against gram-negative bacteria: an overview. 166 90

Although the fluoroquinolones share many properties, these agents differ in their ability to kill the same bacterial strain. The bactericidal activity of temafloxacin against a number of pathogens has been compared with that of other fluoroquinolones by determination of minimal bactericidal concentration, time-kill kinetics, and postantibiotic effect. Studies have demonstrated that temafloxacin has equivalent or superior ability to kill when compared with other fluoroquinolones. Temafloxacin, ciprofloxacin, and PD 117558 were more active than other fluoroquinolones against Mycobacterium avium complex, with 90% minimal bactericidal concentrations (MBC90S; 8-16 micrograms/mL) four- to eightfold greater than 90% minimal inhibitory concentrations (MIC90S; 2 micrograms/mL). Against Chlamydia trachomatis the MIC90 and MBC90 of temafloxacin were both 0.25 microgram/mL; ciprofloxacin was less active (MBC90 twice the MIC90), and norfloxacin was least active. Temafloxacin demonstrated more rapid killing kinetics than did ciprofloxacin or ofloxacin at all concentrations tested against Streptococcus pyogenes. Findings were similar against Streptococcus pneumoniae at antibiotic concentrations of 1-2 micrograms/mL. Similar time-kill curves against Escherichia coli were observed for temafloxacin, ciprofloxacin, and difloxacin. Time-kill kinetics of temafloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) were superior to those of ciprofloxacin and ofloxacin. Postantibiotic effect with temafloxacin against Legionella pneumophila showed a considerable delay in regrowth, and temafloxacin delayed regrowth of MRSA and MSSA to a greater extent than did ciprofloxacin or ofloxacin. By the three methods used in the studies to assess bactericidal activity that are currently published, temafloxacin had equivalent or superior activity to the comparative fluoroquinolones tested. Other organisms remain to be tested and the significance of these findings determined in clinical studies.
Am J Med 1991 Dec 30
PMID:Evaluation of the bactericidal activity of temafloxacin. 166 93


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