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)

Cat scratch disease (CSD) is commonly caused by Bartonella henselae infection. Clinical history and histologic findings are often insufficient to establish a definitive diagnosis of CSD. We retrospectively studied formalin-fixed, paraffin-embedded (FFPE) lymph nodes from 35 patients with histologically suspected CSD by 2 different PCR assays and immunohistochemistry (IHC). The first primer pair amplified a 163-bp fragment of the 16S rRNA gene in 19 of the 35 cases (54%). The second primer pair amplified a 191-bp fragment of the henselae citrate synthase (gltA) gene in 17 of the 35 cases (49%). IHC identified the organisms in 8 of 33 cases (24%). Fresh cultures of various Bartonella species showed a specific PCR product with an analytical sensitivity of 0.5 to 5 pg bacterial DNA. Bartonella species were identified by the unique size of the amplified PCR product. Twenty-two lymph nodes without morphologic evidence or a history of CSD were negative by PCR and immunostaining. Tissues from a patient with Legionella pneumophila were also negative by PCR and immunostaining for CSD supporting the specificity of the PCR reaction. The specific PCR products of the B. henselae were confirmed by sequencing. Human beta-actin for each case was amplified to check the integrity of the DNA. Our data indicate that detection of Bartonella DNA by PCR is useful to confirm the diagnosis of CSD.
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PMID:Diagnosis of cat scratch disease with Bartonella henselae infection in formalin-fixed paraffin-embedded tissues by two different PCR assays. 1610 95

Legionella pneumophila is an aquatic bacterium that is also the agent of Legionnaires' disease pneumonia. Since L. pneumophila is transmitted directly from the environment to the lung, it is important to understand how legionellae survive at low temperatures. To identify genes that are needed for L. pneumophila growth at low temperature, we screened a population of mutagenized legionellae for strains that are specifically impaired for growth at 17 degrees C. From the 7,400 mutants tested, 11 displayed defects ranging from ca. 10-fold to a complete inability to grow at the low temperature. PCR and sequence analysis were then utilized to identify the genes whose loss had compromised growth. The proteins thereby implicated in low-temperature growth included components of the type II secretion system (LspE, LspG, LspH), a lipid A biosynthetic enzyme (LpxP), a ribonuclease (RNAse R), an RNA helicase (CsdA/DeaD), TCA cycle enzymes (citrate synthase), enzymes linked to fatty acid (FadB) or amino acid (aspartate aminotransferase) catabolism, and two putative membrane proteins that were, based upon their sequences, unlike previously characterized proteins. Given the magnitude of their mutant's defect, the aspartate aminotransferase, RNA helicase, and one of the putative membrane proteins were the factors most critical for L. pneumophila low-temperature growth. Thus, L. pneumophila not only employs some of the same processes and factors as other bacteria do in order to survive at low temperatures (e.g., LpxP, CsdA), but it also appears to possess novel modes of cold adaptation.
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PMID:Mediators of lipid A modification, RNA degradation, and central intermediary metabolism facilitate the growth of Legionella pneumophila at low temperatures. 1976 2

Legionella pneumophila (Lp) is commonly found in freshwater habitats but is also the causative agent of Legionnaires' disease when infecting humans. Although various virulence factors have been reported, little is known about the nutrition and the metabolism of the bacterium. Here, we report the application of isotopologue profiling for analyzing the metabolism of L. pneumophila. Cultures of Lp were supplied with [U-(13)C(3)]serine, [U-(13)C(6)]glucose, or [1,2-(13)C(2)]glucose. After growth, (13)C enrichments and isotopologue patterns of protein-derived amino acids and poly-3-hydroxybutyrate were determined by mass spectrometry and/or NMR spectroscopy. The labeling patterns detected in the experiment with [U-(13)C(3)]serine showed major carbon flux from serine to pyruvate and from pyruvate to acetyl-CoA, which serves as a precursor of poly-3-hydroxybutyrate or as a substrate of a complete citrate cycle with Si specificity of the citrate synthase. Minor carbon flux was observed between pyruvate and oxaloacetate/malate by carboxylation and decarboxylation, respectively. The apparent lack of label in Val, Ile, Leu, Pro, Phe, Met, Arg, and Tyr confirmed that L. pneumophila is auxotrophic for these amino acids. Experiments with [(13)C]glucose showed that the carbohydrate is also used as a substrate to feed the central metabolism. The specific labeling patterns due to [1,2-(13)C(2)]glucose identified the Entner-Doudoroff pathway as the predominant route for glucose utilization. In line with these observations, a mutant lacking glucose-6-phosphate dehydrogenase (Delta zwf) did not incorporate label from glucose at significant levels and was slowly outcompeted by the wild type strain in successive rounds of infection in Acanthamoeba castellanii, indicating the importance of this enzyme and of carbohydrate usage in general for the life cycle of Lp.
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PMID:Isotopologue profiling of Legionella pneumophila: role of serine and glucose as carbon substrates. 2044 1