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)

Iron is required for the intracellular and extracellular growth of Legionella pneumophila (Lp). In addition, variations in iron levels may serve as a signal for changes in gene expression. In a number of bacterial pathogens, the regulation of gene expression by iron is usually mediated by the Fur (ferric uptake regulation) repressor protein. Through complementation of an Escherichia coli fur mutation and nucleotide sequence analysis, we have cloned and characterized the Lp fur gene. Lp fur encoded a 15.0-kDa protein whose repressive activity was, as expected, highest in bacteria grown in iron-rich media. Computer analysis determined that Lp Fur had an amino-acid identity of over 54% and a similarity of over 72% to the Fur of E. coli, Yersinia pestis, Vibrio species and Pseudomonas aeruginosa. The promoter region of Lp fur contained sequences homologous to the Fur-binding site, suggesting that fur is autoregulated in Lp. Finally, Southern blot hybridizations demonstrated that fur is conserved among Lp strains and Legionella species.
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PMID:Cloning and sequencing of the Legionella pneumophila fur gene. 820 May 25

An agar dilution technique was used to compare the antimicrobial activities of lomefloxacin, norfloxacin, ofloxacin, ciprofloxacin and enoxacin against 544 strains of bacterial isolates. Among the five quinolone agents tested, ciprofloxacin was the most active. Enoxacin was the most active after ciprofloxacin against Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Shigella spp., Yersinia enterocolitica, and Haemophilus influenzae with an MIC90 of < or = 0.25 micrograms/ml. Ofloxacin was the most active agent after ciprofloxacin against Klebsiella pneumoniae, Enterobacter cloacae, Citrobacter diversus, and Legionella pneumophila with an MIC of < or = 0.25 micrograms/ml. Ciprofloxacin inhibited Staphylococcus spp. and Streptococcus spp., at < or = 0.5 micrograms/ml and 2 micrograms/ml, respectively. Norfloxacin and enoxacin had the same antimicrobial activity (MIC90) against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus agalactiae and some other Gram-positive species, but these activities were weak when compared with ciprofloxacin. The results of this in vitro study show that ciprofloxacin is very active against Gram-negative and Gram-positive species.
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PMID:Comparative antimicrobial activity of lomefloxacin, norfloxacin, ofloxacin, ciprofloxacin and enoxacin against > 500 bacterial isolates. 839 96

Microorganisms have long been suspected of causing Crohn's disease (CD); however, an etiologic agent has yet to be identified. Few studies have employed immunocytochemistry (ICC) to examine tissue from patients with CD for microbial antigens. We investigated 36 formalin-fixed tissues from 16 patients with CD with ICC. No evidence of adenovirus, Borrelia, Brucella, BVDV, Campylobacter, Campylobacter-like organisms, Chlamydia, coronavirus, CMV, EBV, Legionella, mycobacteria, Pseudomonas, rotavirus, Salmonella, Shigella, staphylococci, Toxoplasma gondii, Treponema, or Yersinia was found. ICC identified E. coli and streptococcal antigens in 11 (69%) and 10 (63%) of the 16 cases studied, respectively. Escherichia coli immunoreactivity was located in ulcers, within the lamina propria, and along fissures. Streptococcal immunolabeling occurred within mucosal epithelial cells, in the lamina propria, in ulcers, along fissures, in granulomatous inflammation including multinucleate giant cells, and in lymph nodes. These results suggest that some of the granulomas in CD may result from immunologic processing of bacterial antigens following their penetration through a compromised mucosa. E. coli and streptococcal antigens may contribute to the pathogenesis of CD.
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PMID:An immunocytochemical search for infectious agents in Crohn's disease. 848 93

The data base (DB) "Primers of microorganisms" for the accumulation and systematization of information on oligonucleotide sequences, used as primers in polymerase chain reaction, has been created. This DB includes data on primers for the laboratory diagnostics of 20 bacterial genera (Aerococcus, Aeromonas, Bartonella, Borrelia, Burkholderia, Chlamydia, Clostridium, Corynebacterium, Escherichia, Francisella, Helicobacter, Legionella, Listeria, Mycobacterium, Mycoplasma, Salmonella, Shigella, Staphylococcus, Vibrio, Yersinia) and 6 viral families (Arenaviridae, Flaviviridae, Hepadnaviridae, Herpesviridae, Picornaviridae, Retroviridae). DB contains data on 145 pairs of primers and 530 bibliographic sources. The retrospective depth of DB is 10 years (1987-1996), and it is replenished as new Russian and foreign documented sources of information arrive.
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PMID:[Database on nucleotide sequences used as primers of microorganisms]. 982 98

Successful microbial pathogens must be adept in obtaining growth-essential iron from healthy hosts. Some potential pathogens, however, are sufficiently impaired in iron acquisition ability so as to be dangerous mainly in hosts with such iron loading conditions as alcoholism, asplenia, hemochromatosis, beta-thalassemia major, or tobacco smoking. The association of six impaired pathogens (Capnocytophaga canimorsis, Yersinia enterocolitica and Y. pseudotuberculosis, Vibrio vulnificus, Tropheryma whippelii, and Legionella pneumophila) with iron loaded humans is described.
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PMID:Microbial pathogens with impaired ability to acquire host iron. 1083 Dec 29

Sigma factor sigma(28) (sigma(F), FliA, SigD) directs RNA polymerase to transcribe the genes required for flagellar biosynthesis and chemotaxis in many bacteria, including Bacillus subtilis, Legionella pneumophila, Salmonella typhimurium, Escherichia coli, Yersinia enterolytica, Treponema maltophilum and Pseudomonas aeruginosa. Remarkably the fliA gene from the extreme thermophile Aquifex aeolicus restored motility to the E. coli mutant at relatively low temperature, albeit partially. This clearly demonstrates that A. aeolicus sigma(28) is able to direct RNA polymerase to E. coli sigma(28)-dependent promoters and take part in the complex interactions required to support transcription of the flagellar apparatus in vivo. The ability of A. aeolicus sigma(28) to function with mesophilic components shows that critical functional interactions made by these sigma factors are well conserved, and are not dependent upon high temperature. We over-produced and purified the sigma(28) protein and demonstrated binding to E. coli core RNA polymerase in vitro. In common with SigD from B. subtilis, but unlike most sigma factors, A. aeolicus sigma(28) showed DNA binding activity in vitro but there was no evidence of sequence specificity. We note that A. aeolicus sigma(28) is a good candidate for structural studies.
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PMID:The alternative sigma factor sigma(28) of the extreme thermophile Aquifex aeolicus restores motility to an Escherichia coli fliA mutant. 1100 6

Gatifloxacin is a new 8-methoxy-fluoroquinoline antimicrobial agent. It has enhanced activity against Gram-positive and atypical agents, while retaining broad-spectrum antiGram-negative activity. For example, the MIC(90) values for respiratory tract pathogens are < or = 0.5 microg/ml for organisms such as Streptococcus pneumoniae (regardless of penicillin susceptibility), Haemophilus influenzae (beta-lactamase positive or negative), Moraxella catarrhalis (beta-lactamase positive or negative), Legionella species, Mycoplasma pneumoniae, methicillin-sensitive Staphylococcus aureus, beta-haemolytic Streptococci (macrolide sensitive or resistant), Neisseria species, most Enterobacteriaceae, Neisseria gonorrhoeae, Neisseria meningitidis, Pasteurella species, Vibrio species and Yersinia enterocolitica. For methicillin-resistant S. aureus, ciprofloxacin-resistant S. aureus, Citrobacter freundii, Providencia species, Serratia species, Pseudomonas aeruginosa and other non-fermentative Gram-negative bacilli, the MIC(90) are elevated. Gatifloxacin is bactericidal and exhibits a post-antibiotic effect against Gram-positive and -negative bacteria. The standard dose is 400 mg once daily and is available in both oral and iv. formulation. Gatifloxacin appears to have a low propensity for the selection of resistant mutants. Clinical trial data supports the use of gatifloxacin for treatment of patients with respiratory tract, urinary tract, skin and soft tissue infections. The side effect profile for gatifloxacin is similar to that with other agents.
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PMID:Gatifloxacin: a new fluoroquinolone. 1106 Jul 84

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation.
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PMID:Endocarditis due to rare and fastidious bacteria. 1114 9

Emerging water-borne pathogens constitute a major health hazard in both developed and developing nations. A new dimension to the global epidemiology of cholera-an ancient scourge-was provided by the emergence of Vibrio cholerae O139. Also, water-borne enterohaemorrhagic Escherichia coli ( E. coli O157:H7), although regarded as a problem of the industrialized west, has recently caused outbreaks in Africa. Outbreaks of chlorine-resistant Cryptosporidium have motivated water authorities to reassess the adequacy of current water-quality regulations. Of late, a host of other organisms, such as hepatitis viruses (including hepatitis E virus), Campylobacter jejuni, microsporidia, cyclospora, Yersinia enterocolitica, calciviruses and environmental bacteria like Mycobacterium spp, aeromonads, Legionella pneumophila and multidrug-resistant Pseudomonas aeruginosa have been associated with water-borne illnesses. This review critically examines the potential of these as emerging water-borne pathogens. It also examines the possible reasons, such as an increase in the number of immunocompromised individuals, urbanization and horizontal gene transfer, that may underlie their emergence. Further, measures required to face the challenge posed by these pathogens are also discussed.
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PMID:Emerging water-borne pathogens. 1268 49

The probiotic Escherichia coli strain Nissle 1917 (Mutaflor) of serotype O6:K5:H1 was reported to protect gnotobiotic piglets from infection with Salmonella enterica serovar Typhimurium. An important virulence property of Salmonella is invasion of host epithelial cells. Therefore, we tested for interference of E. coli strain Nissle 1917 with Salmonella invasion of INT407 cells. Simultaneous administration of E. coli strain Nissle 1917 and Salmonella resulted in up to 70% reduction of Salmonella invasion efficiency. Furthermore, invasion of Yersinia enterocolitica, Shigella flexneri, Legionella pneumophila and even of Listeria monocytogenes were inhibited by the probiotic E. coli strain Nissle 1917 without affecting the viability of the invasive bacteria. The observed inhibition of invasion was not due to the production of microcins by the Nissle 1917 strain because its isogenic microcin-negative mutant SK22D was as effective as the parent strain. Reduced invasion rates were also achieved if strain Nissle 1917 was separated from the invasive bacteria as well as from the INT407 monolayer by a membrane non-permeable for bacteria. We conclude E. coli Nissle 1917 to interfere with bacterial invasion of INT407 cells via a secreted component and not relying on direct physical contact with either the invasive bacteria or the epithelial cells.
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PMID:The probiotic Escherichia coli strain Nissle 1917 interferes with invasion of human intestinal epithelial cells by different enteroinvasive bacterial pathogens. 1503 98


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