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)

The in vitro activity of MC-352, 3,4'-dideoxy-5-O-mycaminosyltylonolide, was compared with those of erythromycin, clarithromycin, and rokitamycin. The MC-352 MIC90 (MIC for 90% of isolates) for erythromycin-susceptible Staphylococcus aureus and Staphylococcus epidermidis was less than or equal to 1 microgram/ml, similar to those of the other agents. The MC-352 MIC50 for erythromycin-resistant S. aureus was 2 micrograms/ml, similar to that of rokitamycin. The MC-352 MIC90 (0.12 micrograms/ml) for Streptococcus pyogenes was similar to those of erythromycin and clarithromycin and superior to that of rokitamycin, and the MC-352 MIC90 for group B, C, and G streptococci was 0.25 microgram/ml. MC-352 and clarithromycin had an MIC90 of 0.12 microgram/ml for Streptococcus pneumoniae. Erythromycin-susceptible Enterococcus faecalis was inhibited by MC-352 at 1 microgram/ml, but the MIC for constitutively erythromycin-resistant isolates was greater than 16 micrograms/ml. Legionella pneumophila was inhibited by less than or equal to 0.25 microgram/ml. MC-352 was the most active agent against Bacteroides fragilis, with an MIC90 of 8 micrograms/ml, and was more active than the other agents against Haemophilus influenzae, with an MIC90 of 4 micrograms/ml. Moraxella spp. were inhibited by MC-352 at less than or equal to 0.25 microgram/ml. The MIC90 for Escherichia coli, Klebsiella pneumoniae, and Salmonella, Shigella, Yersinia, Enterobacter, Citrobacter, and Serratia spp. was greater than or equal to 32 micrograms/ml. MC-352 was bactericidal for S. pyogenes and S. pneumoniae, and its activity was not altered by human serum.
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PMID:In vitro activity of MC-352, a new 16-membered macrolide. 141 53

Choosing appropriate antimicrobial therapy for patients with pneumonia requires knowledge of the etiologic agents seen in specific kinds of patients at specific times and places. For community-acquired pneumonia, there is an important difference in the agents seen in the normal and the compromised host. The normal host most often presents with viral, mycoplasmal, or pneumococcal pneumonia. The exact place of Chlamydia pneumoniae is still under study. A normal host who aspirates is at risk of anaerobic pneumonia. Normal hosts with influenza may acquire superinfection with Streptococcus pneumoniae, Haemophilus influenzae, or Staphylococcus aureus. Under specific epidemiologic conditions, community-acquired pneumonia may be due to Legionella species, Yersinia pestis, Francisella tularensis, Coxiella burnetii, Chlamydia psittaci, a mycotic agent, or tuberculosis. Patients with chronic bronchitis and emphysema are predisposed to H. influenzae, Moraxella catarrhalis, and S. pneumoniae infections. HIV-infected patients are likely to have Pneumocystis carinii pneumonia and pneumonia due to cytomegalovirus, S. pneumoniae, and H. influenzae. Patients with diabetes, nursing-home patients, hospitalized patients, immuno-compromised patients, and patients with recent antibiotic therapy are predisposed to pneumonia due to Gram-negative aerobic bacilli of enteric and environmental origin. Initial therapy should be directed at the likely organism or organisms based on hospital susceptibility surveillance. In the normal host with community-acquired pneumonia, the therapy will often be penicillin G or erythromycin. In the patient predisposed to Gram-negative pneumonia, a third-generation cephalosporin with or without an aminoglycoside is the usual choice.
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PMID:Pneumonia. Patient profiles, choice of empiric therapy, and the place of third-generation cephalosporins. 173 Jan 86

Intra-species restriction fragment length polymorphisms (RFLPs) of Yersinia enterocolitica were detected in assays with a cloned DNA fragment from Legionella pneumophila that included the 16S and 23S rRNA genes. By use of this method it was possible to identify different RFLP types within biogroups/serogroups which were indistinguishable by other means. Thus the 37 biogroup IV/serogroup O3 strains isolated worldwide from pig carcasses, pork and human patients, were subdivided into five different RFLP-types. Typing based on RFLP analysis was sensitive and independent of phenotypic characters. The method will be of value for the identification and evaluation of possible reservoirs and routes of infection.
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PMID:Epidemiological typing of Yersinia enterocolitica by analysis of restriction fragment length polymorphisms with a cloned ribosomal RNA gene. 197 36

All Serratia marcescens strains (total of 33) of different sources were hemolytic including clinical strains previously classified as being nonhemolytic. DNA fragments of the two hemolysin genes hybridized with the chromosomal DNA of S. marcescens, S. liquefaciens, S. kiliensis, S. grimesii, S. proteamaculans, S. plymutica, S. rubridaea which were also hemolytic. The restriction pattern of the hemolysin locus differed in each strain. S. ficaria and S. marinorubra expressed a different hemolysin which was much smaller than the S. marcescens hemolysin since it diffused through dialysis membranes. The DNA of the latter strains did not hybridize with the S. marcescens hemolysin DNA probes. Some S. marcescens strains, S. kiliensis and S. liquefaciens also expressed in addition the small hemolysin. No hybridization was found with DNA of Escherichia coli, Salmonella typhimurium, Proteus mirabilis, Proteus vulgaris, Citrobacter freundii, Enterobacter cloacae, Klebsiella arerogenes, Klebsiella pneumoniae, Shigella dysenteriae, Yersinia enterocolitica, Yersinia pseudotuberculosus, Listeria sp., Aeromonas sp., Legionella sp. and a Meninococcus sp., indicating that the hemolysin DNA probes are specific for Serratia, or that the hemolysin genes occur rarely in genera other than Serratia.
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PMID:Hemolysin as a marker for Serratia. 222 20

The macrolide antibiotic azithromycin (CP-62,993; 9-deoxo-9a-methyl-9a-aza-9a-homoerythromycin A; also designated XZ-450 [Pliva Pharmaceuticals, Zagreb, Yugoslavia]) showed a significant improvement in potency against gram-negative organisms compared with erythromycin while retaining the classic erythromycin spectrum. It was up to four times more potent than erythromycin against Haemophilus influenzae and Neisseria gonorrhoeae and twofold more potent against Branhamella catarrhalis, Campylobacter species, and Legionella species. It had activity similar to that of erythromycin against Chlamydia spp. Azithromycin was significantly more potent versus many genera of the family Enterobacteriaceae; its MIC for 90% of strains of Escherichia, Salmonella, Shigella, and Yersinia was less than or equal to 4 micrograms/ml, compared with 16 to 128 micrograms/ml for erythromycin. Azithromycin inhibited the majority of gram-positive organisms at less than or equal to 1 micrograms/ml. It displayed cross-resistance to erythromycin-resistant Staphylococcus and Streptococcus isolates. It had moderate activity against Bacteroides fragilis and was comparable to erythromycin against other anaerobic species. Azithromycin also demonstrated improved bactericidal activity in comparison with erythromycin. The mechanism of action of azithromycin was similar to that of erythromycin since azithromycin competed effectively for [14C]erythromycin ribosomebinding sites.
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PMID:Spectrum and mode of action of azithromycin (CP-62,993), a new 15-membered-ring macrolide with improved potency against gram-negative organisms. 244 65

The results of a study made in the areas of Central Italy on a random community on the significant presence of cases with seroantibodies against Campylobacter, Yersinia, Legionella Pneumophila, Francisella Tularensis and Rotavirus confirm the hypothesis on the presence in the territory of microorganisms responsible. These positivities in man are not only single but also contemporaneous for at least two microorganisms. Hence the hypothesis of the presence in the environment (animals, soil, surface waters) of the microorganisms (Campylobacter, Yersinia, Legionella Pneumophila, Francisella Tularensis, and Rotavirus) responsible for the zoonoses of interest for man.
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PMID:[Old and new pathologies proposed by epidemiology]. 249 Apr 1

The susceptibility of coliform bacteria and bacterial pathogens to free chlorine residuals was determined before and after incubation with amoebae and ciliate protozoa. Viability of bacteria was quantified to determine their resistance to free chlorine residuals when ingested by laboratory strains of Acanthamoeba castellanii and Tetrahymena pyriformis. Cocultures of bacteria and protozoa were incubated to facilitate ingestion of the bacteria and then were chlorinated, neutralized, and sonicated to release intracellular bacteria. Qualitative susceptibility of protozoan strains to free chlorine was also assessed. Protozoa were shown to survive and grow after exposure to levels of free chlorine residuals that killed free-living bacteria. Ingested coliforms Escherichia coli, Citrobacter freundii, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella pneumoniae, and Klebsiella oxytoca and bacterial pathogens Salmonella typhimurium, Yersinia enterocolitica, Shigella sonnei, Legionella gormanii, and Campylobacter jejuni had increased resistance to free chlorine residuals. Bacteria could be cultured from within treated protozoans well after the time required for 99% inactivation of free-living cells. All bacterial pathogens were greater than 50-fold more resistant to free chlorine when ingested by T. pyriformis. Escherichia coli ingested by a Cyclidium sp., a ciliate isolated from a drinking water reservoir, were also shown to be more resistant to free chlorine. The mechanism that increased resistance appeared to be survival within protozoan cells. This study indicates that bacteria can survive ingestion by protozoa. This bacterium-protozoan association provides bacteria with increased resistance to free chlorine residuals which can lead to persistence of bacteria in chlorine-treated water. We propose that resistance to digestion by predatory protozoa was an evolutionary precursor of pathogenicity in bacteria and that today it is a mechanism for survival of fastidious bacteria in dilute and inhospitable aquatic environments.
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PMID:Survival of coliforms and bacterial pathogens within protozoa during chlorination. 322 66

An antigen prepared with agar-grown Legionella pneumophila group 1 killed by 0.5% phenol and suspended in 0.5% yolk sac was examined for use in the indirect immunofluorescence test for legionellosis and compared with a heat-killed antigen. The serological results of the two antigens for single and paired sera agreed well. Morphological and staining characteristics were better for phenol-treated organisms. Electron microscopy observation showed an apparently well-preserved cell surface. The background antibody level among a healthy control population was very low (3.4% with titers of greater than or equal to 16). Sera of patients with gram-negative bacteria infections (Yersinia enterocolytica, Campylobacter jejuni, Salmonella typhimurium, Escherichia coli, Brucella melitensis, Pseudomonas aeruginosa, Mycoplasma pneumoniae, Coxiella burnetti, and Chlamydia psittaci) showed no cross-reactions with the phenol-killed antigen. The data suggest that phenol-killed antigen is sensitive and specific. This antigen is stable for at least 1 year.
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PMID:Comparison of phenol- and heat-killed antigens in the indirect immunofluorescence test for serodiagnosis of Legionella pneumophila group 1 infections. 638 81

A Campylobacter jejuni (Cj) TGH9011 (ATCC 43431) gene homologous to the Escherichia coli ferric uptake regulatory gene (fur) has been cloned and characterized. Cj fur encodes a polypeptide consisting of 157 amino acids (aa) (18.1 kDa). The 5'-flanking region of the Cj fur gene contains two putative catabolite activator protein (CAP)-binding sequences and four Fur boxes or Fur-binding sequences (FBS), implicating cAMP and autogenous regulation respectively. A major and a minor transcription start point (tsp) were active in Fe(+) and Fe(-) media and three tsp were suppressed in Fe(+) condition. The major transcript has an unusually short leader sequence. The homology of the Cj Fur to other Proteobacteria Fur proteins is moderately low with identity ranging from 36.3% for Yersinia pestis to 31.8% for Legionella pneumophila. Multiple alignments of the Fur sequences identified three conserved motifs, I [aGLKvTlpR1KiL], II [eiGlATvYR] and III [HHDHlvCldcGeviEf] (uppercase aa are identical in 12 or all 13 Fur sequences and lowercase aa are identical in six or more sequences). A truncated TGFH9011 Fur missing 18 aa of the N terminus but retaining all three conserved motifs was shown to bind all four FBS sequences. The binding and transcription studies support autoregulation of fur expression in Cj.
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PMID:Cloning and transcription regulation of the ferric uptake regulatory gene of Campylobacter jejuni TGH9011. 759 Mar 16

Salmonellae possess the ability to adhere to and invade macrophages and in so doing trigger a number of intracellular events that are associated with cellular activation. As an initial approach to defining the mechanisms by which invasive salmonellae alter macrophage function, we have explored the impact of Salmonella infection on the production of human immunodeficiency virus (HIV) in U1 cells, a promonocytic cell line latently infected with the virus. Infection of U1 cells with a pathogenic strain of Salmonella enteritidis resulted in a marked induction of macrophage activation and HIV production. The stimulatory effect of salmonellae was mediated by signals other than lipopolysaccharide. Salmonella mutants with specific defects in invasion or intracellular survival were markedly less effective in the induction of HIV production. In contrast to S. enteritidis, strains of Yersinia enterocolitica, Legionella pneumophila, and Escherichia coli did not induce HIV production. However, all of these bacteria induced comparable levels of gene expression mediated by the HIV long terminal repeat. The results of this study are consistent with the notion that invasive salmonellae possess the ability to activate the macrophage by at least one mechanism that is not shared with several other species of gram-negative bacteria. Furthermore, the expression of this unique property is maximal with Salmonella strains that are not only invasive but also capable of prolonged survival within the macrophage. Our results indicate that the U1 cell line may be a very useful model system with which to examine the biochemical pathways by which internalized salmonellae modulate the activation state of the macrophage.
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PMID:Regulation of macrophage activation and human immunodeficiency virus production by invasive Salmonella strains. 772 90


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