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

The in-vitro activity of RP 59500 was determined against 1051 recent clinical bacterial isolates. The susceptibility to RP 59500 was determined with an agar dilution technique for all the isolates, while MICs and MBCs were determined for 82 selected strains in broth. Isolates of both Staphylococcus aureus and coagulase-negative staphylococci appeared to be potentially susceptible to RP 59500, independent of susceptibility to methicillin or MLS resistance. (S. aureus: methicillin-sensitive, MIC90, 1.0 mg/L; methicillin-resistant, MIC90 1.0 mg/L; coagulase-negative staphylococci: methicillin-sensitive, MIC90 0.5 mg/L). Lancefield group A, B, C and G streptococci (MIC50 0.5 and MIC90 1.0 mg/L) and Streptococcus pneumoniae (MIC50 0.5 and MIC90 1.0 mg/L) appeared to be susceptible to RP 59500. Some Streptococcus spp. and enterococci as well as Listeria monocytogenes were inhibited by a higher concentration of RP 59500 (enterococci: MIC90 4 mg/L, range 0.125-16 mg/L). Comparatively low MICs were seen when Legionella spp., Neisseria gonorrhoeae and Gardnerella vaginalis were tested. Broth dilution MIC/MBC determinations showed no evidence of tolerance, as MIC values were within two dilutions of MBC values. RP 59500 might be a useful compound in the treatment of infections caused by a range of Gram-negative and Gram-positive bacteria, including those resistant to methicillin and/or macrolides.
 ...
PMID:A collaborative study of the in-vitro sensitivity to RP 59500 of bacteria isolated in seven hospitals in France. 139 51

Indole-3-propionic acid (IPA), a phytohormone derivative, is a potent inhibitor of growth of Legionella pneumophila cultivated extracellularly in a chemically defined hypotonic medium and intracellularly in human monocytes. The inhibitory activity turns into bactericidal activity with increasing concentrations. The susceptibility of the microorganism to IPA was more evident in "fast-growing" cultures (under conditions of vigorous shaking) than in static cultures growing under an atmosphere of 5% CO2-95% air, which resulted in a decreased growth rate. The MIC, after incubation with the drug for 48 h and as determined by counting of the CFU, was 1.58 microM for fast-growing cultures and 2.64 microM for those grown under static conditions. The MBCs were 5.28 and 26.43 microM, respectively. Tryptophan (Trp) at 150 microM prevented the inhibition caused by 2.64 microM IPA, increased the MIC about 3-fold, and increased the MBC by 10-fold. The effect of Trp was less remarkable in "slow-growing" cultures. The susceptibility of L. pneumophila proliferating in human monocytes was markedly lower than that when it was cultivated extracellularly in the chemically defined hypotonic medium. The MIC after incubation for 48 h was 5.28 microM, and a decrease in viable count was achieved with 105.70 microM. The lower susceptibility was apparently due (at least partially) to the presence of Trp (24.50 microM) in the RPMI 1640 medium that was used for the monocyte cultures. The effect of IPA was time dependent, and prolonged exposure enhanced the bactericidal activity and turned the inhibitory dose into a bactericidal dose. The present data demonstrate that IPA is a potent anti-L. pneumophila factor, although it has a markedly lower activity against bacteria growing intracellularly compared with its activity against extracellularly proliferating microorganisms.
 ...
PMID:Susceptibility of Legionella pneumophila grown extracellularly and in human monocytes to indole-3-propionic acid. 181 Jan 85

Dirithromycin is a 9-N-11-O-oxazine derivative which is formed by condensation of 9(S)-erythromycylamine with 2-(2-methoxyethoxy)acetaldehyde. Dirithromycin is hydrolyzed, either under acidic conditions or in vivo, to its major active metabolite, 9(S)-erythromycylamine. The antimicrobial spectrum of dirithromycin is similar to that of erythromycin; both antibiotics are active against gram-positive bacteria, Legionella spp., Helicobacter pylori, and Chlamydia trachomatis. Comparable results were obtained for each antibiotic in MIC and MBC determinations and in the potential development of resistance in vitro. The effects of human serum, bacterial growth media, test methodology, and inoculum size on MICs were similar for each antibiotic. In standard mouse protection studies, dirithromycin was more efficacious than erythromycin against experimental infections after subcutaneous administration of antibiotic. These results were consistent with pharmacokinetic studies in rodents, which showed that dirithromycin gave more persistent concentrations of antibiotic in serum and tissues than were achieved with erythromycin. These studies indicate that dirithromycin possesses antimicrobial activity comparable to that of erythromycin in vitro but is more active than erythromycin in vivo, which may be attributable to the persistence of antimicrobial activity in the tissue(s) of the test animals.
 ...
PMID:Synthesis and antimicrobial evaluation of dirithromycin (AS-E 136; LY237216), a new macrolide antibiotic derived from erythromycin. 192 52

YM133, the 4"-O-(4-methoxyphenyl)acetyltylosin, is a new macrolide. The in vitro activity of YM133 was compared with those of erythromycin, josamycin, and rokitamycin by an agar dilution method. YM133 inhibited 90% of the tested isolates of Streptococcus pneumoniae, Legionella spp., and anaerobic bacteria at less than or equal to 1.56 micrograms/ml. The drug inhibited 90% of erythromycin-resistant staphylococci and Streptococcus pyogenes at less than or equal to 50 micrograms/ml. YM133 showed activity against erythromycin-, josamycin-, and rokitamycin-resistant (MIC greater than or equal to 100 micrograms/ml) strains of staphylococci, streptococci, Bacteroides spp., and Clostridium spp. Enterococci were less susceptible to other YM133-like macrolides. Unlike other macrolides, YM133 showed killing activity, and the MBC/MIC ratios of YM133 for several strains were 1:32, whereas those of erythromycin were 4:1,024. In a time-kill curve study, the reduction of viable cells started within 2 h after the addition of YM133.
 ...
PMID:In vitro activity of YM133, a new semisynthesized macrolide. 192 95

On 1 May 1988 a senior Naval Officer, serving at HMS Warrior, was admitted to RAF Halton where a diagnosis of Legionnaire's disease was made. He suffered severe pneumonia and neurological symptoms, and although he eventually responded to treatment, he still suffers sequelae. On 19 April, he was in the vicinity of the BBC at the time of the outbreak of Legionnaire's disease. His clinical findings are reported in this article along with a brief history and discussion of the diagnosis and prevention of Legionnaire's disease.
 ...
PMID:A severe case of Legionnaire's disease connected to the BBC outbreak in 1988. 260 95

The inhibitory (MIC) and bactericidal (MBC) activities of a new macrolide A-56268 (TE-031) against 306 clinical aerobic bacterial isolates was compared with that of erythromycin. The MIC90/MBC90 ratios for A-56268 were: Campylobacter jejuni 4/16, Haemophilus influenzae 8/8-16, H. parainfluenzae 8/8-16, Legionella pneumophila 0.06/0.5, methicillin-sensitive isolates of Staphylococcus aureus 0.5/1, and coagulase negative staphylococci 1/8, methicillin resistant isolates of Staph. aureus and coagulase negative staphylococci greater than 16/ greater than 16, Streptococcus pneumoniae 0.06/0.125, streptococcus Group A 0.06/2-4, streptococcus Group B 0.06/8- greater than 16, streptococcus Groups C and G 0.125/8 and Str. faecalis 4/64. Compared with erythromycin, A-56268 had greater inhibitory and bactericidal activity against isolates of L. pneumophila, with an MIC90 16-fold less and an MBC90 eight-fold less than that of erythromycin. Except for enterococci, A-56268 showed inhibitory activity equal to or greater than that of penicillin G against isolates of streptococci and an MIC two-fold less than that of erythromycin. For other strains tested, the inhibitory and bactericidal activities of A-56268 and erythromycin were similar. The clinical importance of the differences between these two macrolides will depend on the pharmacokinetic and tissue penetration properties of the new compound.
 ...
PMID:Comparative in-vitro activities of A-56268 (TE-031) and erythromycin against 306 clinical isolates. 296 68

MICs of ciprofloxacin (CIP), ofloxacin (OFL) and norfloxacin (NOR) were assessed with a total of 523 strains of 7 species (spp) of enterobacteriaceae, various pseudomonads, methicillin-susceptible and -resistant S. aureus, L. monocytogenes, Legionella species and C. difficile. In addition, the MBCs were assessed with S. aureus and E. coli. With break-points of less than or equal to 0.5 and greater than or equal to 4 mg/l all strains of E. coli, K. oxytoca, P. mirabilis and indole-positive Proteus spp. were susceptible to all 3 antibiotics. Proportions of susceptible strains almost as high were found with E. cloacae, S. marcescens, K. pneumoniae and methicillin-susceptible staphylococci. With Legionella spp. the MICs of CIP and OFL always indicated susceptibility, whereas with NOR only 62% of the strains were inhibited. Pseudomonads, especially others than P. aeruginosa, were only moderately susceptible to CIP and OFL, but never to NOR. Listeria monocytogenes was susceptible to OFL in 96%, to CIP in 56%, but never to NOR. C. difficile was always resistant. The MBC-values either equalled the MICs or surpassed them up to 2 times at maximum indicating a bactericidal mode of action. Despite of slightly lower MICs of CIP in vitro, OFL seems to be comparably effective. NOR is regarded less effective.
 ...
PMID:[The antibacterial effect of ciprofloxacin, ofloxacin and norfloxacin in vitro]. 322 34

The penetration and persistence in the serum and lungs of guinea pigs after parenteral administration of erythromycin, gentamicin, chloramphenicol and rifampicin, and their in-vitro activities against Legionella pneumophila were investigated. The most active agent was rifampicin (MIC 0.0625 mg/l, MBC 0.125 mg/l) and effective levels of this drug were present in serum and lungs up to 10 h after injection. Erythromycin accumulated to very high levels in the lungs and had good bacteriostatic activity in vitro. Gentamicin was highly bactericidal in liquid culture but showed poor lung penetration on injection. Chloramphenicol, the least inhibitory of the four antibiotics, had an MIC of 1.0 mg/l. Active chloramphenicol was not detected in guinea pig serum and lungs following ip or im administration. The differences in the penetration and persistence of these drugs in the lungs of guinea pigs may explain the reported poor correlation between in-vitro and in-vivo activity against L. pneumophila. The results are useful for evaluating regimens for therapy of Legionnaires' disease in the aerosol infected guinea pig model.
 ...
PMID:Persistence in serum and lungs of guinea pigs of erythromycin, gentamicin, chloramphenicol and rifampicin and their in-vitro activities against Legionella pneumophila. 663 Jan 6

The activity of six intracellular antibiotics, doxycycline, erythromycin, clarithromycin, azithromycin, rifampicin and ciprofloxacin, was tested against 60 strains of Legionella pneumophila (21 of human and 39 of environmental origin). MIC50, MIC90, and MBC values were determined by a microdilution method. Inhibitory and bactericidal activity against human and environmental isolates were similar except for rifampicin, which was 100-fold less active for human strains than for environmental strains, particularly in terms of bactericidal activity. Nevertheless, in general, rifampicin was found to be the most active drug. Among the macrolides tested, clarithromycin showed the greatest activity in MIC assays and erythromycin was the least bactericidal. Azithromycin showed higher MICs and MBCs than the two macrolides, and doxycycline was the least active. The most important factors influencing in-vivo activity of antibiotics are discussed. Even if the in-vitro results cannot be fully extrapolated to activity in vivo, these results indicate the susceptibility of L. pneumophila strains in Italy as a basis for treatment of atypical pneumonia that may be due to Legionella spp.
 ...
PMID:In-vitro activity of six intracellular antibiotics against Legionella pneumophila strains of human and environmental origin. 805 94

The antibacterial effects of clarithromycin, azithromycin, and erythromycin were determined against five strains of Legionella pneumophila including L. pneumophila ATCC 33823 and four clinical isolates. Extracellular minimum inhibitory concentrations (MICs) and MBCs were determined by a microdilution method. Clarithromycin was the most active drug (MIC < or = 0.015-0.06), followed by azithromycin (MIC 0.03-0.12) and erythromycin (MIC 0.06-0.25). The antibacterial effect of these macrolides was then determined against L. pneumophila grown intracellularly in MRC-5 human fetal lung fibroblast cells. At two and eight times the extracellular MBC, erythromycin, azithromycin, and clarithromycin were equally effective in inhibiting growth of these five strains of intracellular L. pneumophila.
 ...
PMID:In vitro activity of macrolides against intracellular Legionella pneumophila. 890 7


1 2 Next >>