Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the efficacy and safety of bronchoscopy with bronchoalveolar lavage (BAL) in mechanically ventilated patients. Seventy-seven patients, 60 of whom underwent BAL, were analyzed. Of the patients undergoing BAL, 30 had clinical pneumonia, 24 had a diagnosis other than pneumonia by clinical criteria or autopsy, and six could not be classified but clinically improved without changing their antibiotic therapy. Of the 30 pneumonia patients, 18 had bacterial cultures felt to be diagnostic of bacterial pneumonia: two cases of Legionella pneumophila, and 16 cases with one or more organisms recovered at greater than 10(4) cfu/ml of BAL fluid. No patient without the clinical diagnosis of pneumonia had a positive bacterial culture greater than 10(4) cfu/ml of BAL fluid (chi-square = 18.2, p less than .001). Of the patients classified with pneumonia, Pneumocystis carinii was found in six and cytologic evidence of viral infection in three patients. Of the 30 patients undergoing BAL with pneumonia, 27 had one or more pathogens identified in the lavage specimen. Although no patient died as a result of lavage, significant hypoxemia was encountered in some patients undergoing lavage. In 35 patients with the same FIO2 before and after bronchoscopy, the median change in PO2 was -8.0 torr (range -63.0 to +29.0). We found that bacterial cultures of BAL fluid appeared useful in defining the presence and etiology of pneumonia.
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PMID:Use of bronchoalveolar lavage to diagnose bacterial pneumonia in mechanically ventilated patients. 229 9

A large outbreak of influenza-like and diarrhoeal illness took place over a period of 21 days in April 1984 on board a ship cruising to ports in southern Europe and northern Africa. A cohort study of the 418 passengers was made by postal questionnaire and personal interview. Of the 391 passengers who were interviewed or who returned a questionnaire, 335 (86%) were affected. Of the ill passengers, 295 (88%) had an influenza-like illness. These included 20 with signs of lower respiratory tract infection. In 24 passengers, a viral infection was diagnosed. Influenza B virus infection was identified in 14 cases; other diagnoses were influenza A, para-influenza, respiratory syncytial virus and Epstein-Barr virus infections. In two of the 81 patients tested for Legionella antibodies, a titre of 128 was found; in 16 and 44 patients, titres of 64 and 32 respectively. The outbreak was thus evidently caused by multiple pathogens mainly affecting the respiratory tract. Although most of the passengers acquired their infections on board the ship, a common source was not discovered. A steep rise in the epidemic curve the day after the air-conditioning was switched on, however, is worth noting. If and when similar instances of the 'Sick Boat Syndrome' recur, a search for environmental sources of infection is to be recommended.
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PMID:Outbreak of respiratory illness on board a ship cruising to ports in southern Europe and northern Africa. 358 36

Serum samples from patients with documented influenza A virus infections were examined for antibodies to Legionella pneumophila and Mycoplasma pneumoniae to determine whether simultaneous or sequential infections with L. pneumophila and M. pneumoniae were complicating factors in influenza. When the frequency of copositivity of sera to influenza A virus and L. pneumophila was compared with the expected frequency for each infection alone, the difference was not statistically significant. However, when the frequency of copositivity of sera to influenza A virus and M. pneumoniae was compared with the expected frequency for each infection alone, there was a statistically significant (P less than 0.005) absence of coincident titers. Seasonal variations and differences in relative age frequencies for the two infections may partially explain the absence of coinfections. These data also suggest that in patients with either M. pneumoniae or influenza A virus infection, some type of protective mechanism which prevents coinfections with these organisms is present.
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PMID:Coinfections of Mycoplasma pneumoniae and Legionella pneumophila with influenza A virus. 682 98

Acute bronchitis is usually a viral infection which, unless there is a special disposition, does not require antibiotic therapy. For the initial oral chemotherapy of bacterial infections of the lower respiratory tract (chronic bronchitis, pneumonia) the effective and well tolerated cephalosporins, macrolides and amoxicillin plus beta-lactamase-inhibitor are recommended. In complicated cases with severe underlying disease, longer history or frequent exacerbations, quinolones should be given if Gram-negative infections are suspected or if initial therapy with other substances has failed. If Legionella, Mycoplasma or Chlamydia spp., so-called 'atypical' pathogens, are involved, macrolide antibiotics are the therapy of first choice. Special attention should be given to the increase in resistance against cotrimoxazole (trimethoprim-sulfamethoxazole) and tetracyclines. In hospitals where primary pneumonias are treated preferentially by intravenous medication, therapy should be switched to oral antibiotics as soon as feasible (follow-up therapy). For severely ill patients with secondary pneumonia and underlying disease, second generation cephalosporins with aminoglycosides, or monotherapy with third generation cephalosporins are recommended. In very severe, high-risk cases, third generation cephalosporins, combinations with high-dosage quinolones or ureidopenicillins plus beta-lactamase-inhibitors are suitable. Future development in the antibiotic treatment of respiratory infections will follow the current trend of lower dosages, with the clear objective of shortening treatment periods and achieving earlier discharge from hospital.
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PMID:A guide to the treatment of lower respiratory tract infections. 758 90

Community-aquired pneumonia caused by atypical bacteria or viruses was studied in a double-blind trial comparing fleroxacin 400 mg od and doxycycline 100 mg bd for 10 days. The aetiology was confirmed in 258 of 411 cases (66%), of which 133 were caused by Mycoplasma spp., Chlamydia spp. or Legionella spp.; 30 patients had viral infection, nine had pneumococcal or Haemophilus influenzae infection and 93 had mixed aetiology. In intention-to-treat analyses clinical response rates in fleroxacin-treated patients were 86% (157/182) and 75% (137/182) 2-8 days and 3-5 weeks after therapy, respectively. Corresponding results with doxycycline were 93% (177/191) and 85% (162/190), respectively. Differences between treatments seemed to be due to the lower activity of fleroxacin compared with doxycycline against mycoplasma and pneumococci. Drug-related adverse events were reported in 39% of 204 fleroxacin patients and in 34% of 207 doxycycline patients. The null hypothesis that fleroxacin was <15% inferior to doxycycline was accepted at early follow-up but rejected at later review.
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PMID:Atypical pneumonia in the Nordic countries: aetiology and clinical results of a trial comparing fleroxacin and doxycycline. Nordic Atypical Pneumonia Study Group. 914 23

Adult patients hospitalised with community-acquired pneumonia were studied prospectively to determine the microbial aetiology of pneumonia. Between April 1996 and March 1997, blood and sputum samples were collected for culture. Throat swabs were obtained for isolation of viruses and for detection of antigens of Chlamydia pneumoniae, influenza viruses A and B, respiratory syncytial virus and parainfluenza virus. Antibodies against Legionella spp., Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, influenza viruses A and B, respiratory syncytial virus, adenovirus and parainfluenza virus were tested in serum samples. Two hundred eleven patients were included in the study; paired sera were available from 152 patients. Blood culture was positive in 23 (10.9%) patients, Streptococcus pneumoniae being the bacterium isolated most frequently. A fourfold or greater rise or fall in the Chlamydia pneumoniae IgG and/or IgM antibody titre was found in 20 (9.5%) patients and a high antibody titre (> or = 1:512) in the first and/or the second serum sample in 18 (18.5%) patients. Antibodies confirming acute Mycoplasma pneumoniae infection were found in 12 (5.7%) patients, Legionella spp. in six (2.8%), Chlamydia psittaci in two and Coxiella burnetii in one. Three patients had pulmonary tuberculosis. Only two patients had a virus present in the throat swab (adenovirus in one patient and echovirus in the other), and in nine patients, viral antigen was detected. Acute viral infection was confirmed in 51 (24.1%) patients. Bacterial pneumonia was diagnosed in 84 (39.8%) patients, 23 of whom had concurrent viral infection. Acute viral pneumonia without any other identified pathogen was diagnosed in 28 patients. Streptococcus pneumoniae and Chlamydia pneumoniae were the most frequently identified microorganisms.
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PMID:Microbial aetiology of community-acquired pneumonia in hospitalised patients. 1061 51

Acute exacerbations of asthma are frequently caused by viral infections, but the inflammatory mechanisms in virus-induced asthma are poorly understood. The aim of the present study was to determine whether viral infection in acute asthma was associated with increased sputum neutrophil degranulation and increased cellular lysis and whether these changes are related to clinical severity. Adults (n=49) presenting to the emergency department with acute asthma were examined for infection by means of sputum direct-fluorescence antigen detection, sputum culture, and sputum polymerase chain reaction for Mycoplasma, Chlamydia and Legionella pneumophila, and all common respiratory viruses. Subjects infected with one of these agents were classed as having an infective exacerbation. Spirometry and sputum induction were performed on presentation and 4-5 weeks later. Thirty-seven subjects (76%) had virus infection and acute asthma. Those with virus infection had increased sputum neutrophils (p<0.05) and increased neutrophil elastase (p<0.05), this was related to increased elevated sputum lactate dehydrogenase (LDH). Subjects with noninfective asthma had an increase in the proportion of sputum eosinophils. Both groups had elevated sputum eosinophil cationic protein (ECP) concentrations. Higher levels of sputum LDH and ECP were associated with a longer hospital stay. Virus infection and acute asthma is associated with neutrophilic inflammation, cell lysis and more severe clinical disease.
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PMID:Neutrophil degranulation and cell lysis is associated with clinical severity in virus-induced asthma. 1185 95

Bacterial respiratory tract infections (RTIs), whether primary or subsequent to viral infection, are a frequent cause of morbidity and mortality worldwide. Treatment of these infections is most often empirical. Therefore, an antimicrobial's antibacterial spectrum must include the most likely pathogens: Streptococcus pneumoniae, the most frequent cause of community-acquired pneumonia (CAP), Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus, as well as atypicals such as Mycoplasma pneumoniae, Legionella pneumophila and Chlamydophila (Chlamydia) pneumoniae. In addition, knowledge of antimicrobial resistance among these key pathogens is imperative for physicians to choose the most appropriate therapeutic agent. The latest data from global surveillance studies indicates that high-level resistance to penicillin (MIC > or =2 mg/l) among isolates of S. pneumoniae varies widely by geographic location. Rates exceed 20% in the USA, Mexico, Japan, Saudi Arabia, Israel, Spain, France, Greece, Hungary, and the Slovak Republic. In South Africa, Hong Kong, Taiwan, and South Korea rates exceed 50%. Penicillin non-susceptibility--including isolates exhibiting high-level resistance and intermediate susceptibility (MIC 0.12-1 mg/l)--is frequently found in association with macrolide resistance, which is found at a prevalence of 70-80% in some Asian countries. Trimethoprim-sulfamethoxazole (TMP-SMX) and tetracycline resistance, either individually or combined with macrolide resistance as multiple resistance, is also associated with reduced susceptibility to penicillin. Another concern about antimicrobial resistance in respiratory tract pathogens is beta-lactamase production among isolates of H. influenzae and M. catarrhalis. However, respiratory fluoroquinolones, of which levofloxacin has been available for the longest time, currently remain active against the great majority of common bacterial respiratory pathogens, including atypicals.
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PMID:Comparative antimicrobial susceptibility of respiratory tract pathogens. 1531 48

Nucleic acid recognition upon viral infection triggers type I interferon production. Viral RNA is detected by both endosomal, TLR-dependent and cytosolic, RIG-I/MDA5-dependent pathways. TLR9 is the only known sensor of foreign DNA; it is unknown whether innate immune recognition of DNA exists in the cytosol. Here we present evidence that cytosolic DNA activates a potent type I interferon response to the invasive bacterium Listeria monocytogenes. The noninvasive Legionella pneumophila triggers an identical response through its type IV secretion system. Activation of type I interferons by cytosolic DNA is TLR independent and requires IRF3 but occurs without detectable activation of NF-kappaB and MAP kinases. Microarray analyses reveal a unique but overlapping gene-expression program activated by cytosolic DNA compared to TLR9- and RIG-I/MDA5-dependent responses. These findings define an innate immune response to DNA linked to type I interferon production.
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PMID:Recognition of cytosolic DNA activates an IRF3-dependent innate immune response. 1641 26

Mycoplasma, Chlamydia and Legionella are the usual organisms considered to be the etiologic agents of 'atypical' pneumonia. Other microorganisms such as bacteria, viruses, parasites, fungi and mycobacteria can also present with atypical pneumonia manifestations. Outbreaks and isolated cases of respiratory viruses with atypical pneumonia presentations have been reported among immunocompetent and immunosuppressed patients. Severe infections due to these respiratory viruses alone or as a concomitant bacterial or viral infection have been observed. Additionally, in endemic areas, certain zoonotic infections may present as atypical pneumonia.
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PMID:The other causes of 'atypical' pneumonia. 1703 67


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