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PubMed2003

The cDNA microarray analysis using an Arabidopsis pad3 mutant reveals the expression profiles and classification of genes induced by Alternaria brassicicola attack.

The hypersensitive response (HR) was induced in a wild-type Arabidopsis thaliana plant (Columbia) (Col-wt) by inoculation with Alternaria brassicicola that causes the development of small brown necrotic lesions on the leaves. By contrast, pad3-1 mutants challenged with A. brassicicola produced spreading lesions. The cell death in pad3-1 mutants could not inhibit the pathogen growth and development, although both production of H(2)O(2) and localized cell death were similar in Col-wt and pad3-1 plants after the inoculation. The difference between Col-wt and pad3-1 plants is defense responses after the occurrence of cell death. In other words, PAD3 is necessary for defense response to A. brassicicola. Therefore, we examined the changes in the expression patterns of ca. 7,000 genes by cDNA microarray analysis after inoculation with A. brassicicola. The cDNA microarrays were also done to analyze Arabidopsis responses after treatment with signal molecules, reactive oxygen species (ROS)-inducing compounds and UV-C. The results suggested that the pad3-1 mutation altered not only the accumulation of camalexin but also the timing of expression of many defense-related genes in response to the challenge with A. brassicicola. Furthermore, the plants integrate two or more signals that act together for promoting the induction of multiple defense pathways.

Alternaria↗
PubMed2004

Compilation of a MALDI-TOF mass spectral database for the rapid screening and characterisation of bacteria implicated in human infectious diseases.

A database of MALDI-TOF mass spectrometry (MS) profiles has been developed with the aim of establishing a high throughput system for the characterisation of microbes. Several parameters likely to affect the reproducibility of the mass spectrum of a taxon were exhaustively studied. These included such criteria as sample preparation, growth phase, culture conditions, sample storage, mass range of ions, reproducibility between instruments and the methodology prior to database entry. Replicates of 12 spectra per sample were analysed using a 96-well target plate containing central wells for peptide standards to correct against mass drift during analysis. The quality of the data was assessed statistically prior to database addition using root mean squared values of <3.0 as the criterion for rejection. Cluster analysis using a nearest neighbour algorithm also enabled subsets of data to be compared. This was achieved using the bespoke MicrobeLynx trade mark software. Columbia blood agar was used to standardise all procedures for the database, since it permitted the culture of most human pathogens and also produced spectra with a broad range of mass ions. In some instances, alternative media such as CLED were used in specific studies with greater success. Following standardisation of the procedure, a database was developed comprising ca. 3500 spectra with multiple strain entries for most species. The results to date show unequivocally that as the number of strains per species increased, so too did the success of species matching. The technique demonstrated unique mass spectral profiles for each genus/species, with the variation in mass ions among strains/species being dependent on the intra-specific diversity. The success of identification against the database for wild-type strains ranged between 33 and 100%; the lower percentage results being generally associated with poor representation of some species within the database. These findings provide a new dimension for the rapid and high throughput characterisation of human pathogens with potentially broad applications across the field of microbiology.

Algorithms↗
PubMed1994

Multilocus enzyme electrophoresis on agarose gel as an aid to the identification of entomopathogenic Bacillus sphaericus strains.

Sixty strains of Bacillus sphaericus, including 31 insect pathogens were studied by multilocus enzyme electrophoresis and were classified into 44 zymovars (electrophoretic types). Among the entomopathogenic strains, 11 belong to the same zymovar (Z59) indicating a widespread frequent genotype. Bands of enzyme activity were not detected among the strains for the loci GPI (E.C.5.3.1.9), G6P (E.C.1.1.1.49), 6PG (E.C.1.1.1.44) and ME (E.C.1.1.1.40). The enzymatic loci NP (E.C.2.4.2.1) and ACON (E.C.4.2.1.3) were monomorphic while the other enzymes, MDH (E.C.1.1.1.37), LeDH (E.C.1.4.1.9), ADH (E.C.1.4.1.1), EST (E.C.3.1.1.1), PEP-2 (E.C.3.4.11.1), PEP-3 (E.C.3.4.11) and PEP-D (E.C. 3.4.13.9) were polymorphic. The genetic variation in the non-insect pathogenic group seemed to be greater than in the entomopathogenic group. This latter group appears to be distinct from other strains of these species. All insect pathogens were recovered in the same phenetic cluster and a diagnostic allele is reported for the identification of entomopathogenic strains.

Animals↗
PubMed1996

Genetic variation in arthropod vectors of disease-causing organisms: obstacles and opportunities.

An overview of the genetic variation in arthropods that transmit pathogens to vertebrates is presented, emphasizing the genetics of vector-pathogen relationships and the biochemical genetics of vectors. Vector-pathogen interactions are reviewed briefly as a prelude to a discussion of the genetics of susceptibility and refractoriness in vectors. Susceptibility to pathogens is controlled by maternally inherited factors, sex-linked dominant alleles, and dominant and recessive autosomal genes. There is widespread interpopulation (including intercolony) and temporal variation in susceptibility to pathogens. The amount of biochemical genetic variation in vectors is similar to that found in other invertebrates. However, the amount varies widely among species, among populations within species, and temporally within populations. Biochemical genetic studies show that there is considerable genetic structuring of many vectors at the local, regional, and global levels. It is argued that genetic variation in vectors is critical in understanding vector-pathogen interactions and that genetic variation in vectors creates both obstacles to and opportunities for application of genetic techniques to the control of vectors.

Animals↗
PubMed1988

Rapidly progressive glomerulonephritis: classification, pathogenetic mechanisms, and therapy.

Immunopathologic studies over the past two decades have demonstrated that rapidly progressive glomerulonephritis (RPGN) can result from glomerular deposition of anti-GBM antibody, immune complexes, or from some as yet undefined mechanism that does not involve glomerular antibody deposition. The latter process may be cell mediated and resembles a small vessel vasculitis. Most cases of idiopathic RPGN are not accompanied by pathogenic glomerular immunoglobulin deposition. Recent experimental studies of immune mechanisms of glomerular injury have identified several new processes that can induce damage to the capillary wall sufficient to result in crescentic glomerulonephritis (GN). These include direct effects of anti-GBM antibody alone and of the complement C5b-9 (membrane attack) complex, nephritogenic effects of inflammatory effector cells that involve reactive oxygen species and glomerular halogenation, and injury mediated by sensitized lymphocytes independently of antibody deposition. Macrophages have been shown to participate in both intracapillary and extracapillary fibrin deposition and crescent formation as well as to mediate capillary wall damage. The role of resident glomerular cells and cell-cell interactions in glomerulonephritis is still under active investigation. Despite these several advances in understanding immune injury to the glomerulus, therapy for RPGN remains largely empiric. Although the prognosis in RPGN has clearly improved over time, no form of disease-specific therapy has been clearly shown yet to be beneficial in a controlled study. Interpretation of the existing literature on therapy is complicated by the availability of only historical rather than concurrent controls, lack of attention to several variables known to affect disease outcome, and uncertainty regarding bias in favor of reporting positive results. Available data suggests that optimal outcomes may be achieved in anti-GBM nephritis by treatment with steroids, immunosuppression and plasma exchange, particularly when therapy is directed at patients with mild but rapidly progressive disease before oliguria or severe azotemia develop. Pulse steroids are probably the most cost-effective therapy for the idiopathic form of RPGN, but treatment with cytotoxic agents should be considered if clinical or histologic evidence of vasculitis is present.

Glomerulonephritis↗
PubMed1975

[Demonstration of pathogens in lymphogranuloma inguinale. An electron microscopy study].

A case of lymphogranulomatosis inguinalis is reported, in which the definite diagnosis was made by the electronmicroscopical demonstration of Chlamydia lymphogranulomatosis in the lymphnode. The value of this diagnostical method is discussed in regard to verifying the diagnosis and in comparison with other methods. The lifecycle of the Chlamydia lymphogranulomatosis could be demonstrated electronmicroscopically. Its exceptional position in microbiological classification is discussed.

Adult↗
PubMed1997

[Incidence of inflammatory placental changes in threatened premature labor with and without additional antibiotic therapy].

Considering the causal association of silent intrauterine infection and prematurity we investigated the possible effect of adjuvant antibiotic treatment of women with preterm labour on the appearance of inflammatory placental lesions. 140 patients with preterm labour in the 30 + 2 week of gestation (median; range: 17 + 2-34 + 6) without premature rupture of the membranes and detection of facultative-pathogenic micro-organisms in the vagina and/or in the canal of the cervix were enrolled in the study. 74 women were treated vaginally (polyvidone-iodine) in addition to intravenous tocolysis, 66 women were given ampicillin, cefotiam or erythromycin intravenously. After delivery the placentas were examined histologically and the frequency of inflammatory lesions was evaluated by use of 4 scores of classification. For statistical analysis the Fisher Exact- and the Wilcoxon Rank Sum Test were used. We found no differences concerning amnamnestic and perinatal parameters comparing the 2 groups of patients. With only one of the histological scores used (according to Salafia et al. [18]) we found a higher frequency of inflammatory placental lesion in the antibiotic treated group (12/66) in comparison to the vaginal treated group (4/74). Fifty patients of the antibiotics' group received the antibiotic during the last 10 days before birth. No differences in the frequency of inflammatory placental lesions were detectable in these patients when compared with the local treated group. However, we found a lower prolongation of gestation (calculated from the day of admission to the day of delivery, median: 7; range: 1-92 days) and a lower gestational age at delivery (median: 33 + 0; range: 22 + 2-39 + 6 weeks) in the patients receiving antibiotics during the last 10 days before birth in comparison to the local treated women (22; 1-138 days and 35 + 0; 23 + 4-41 + 5 weeks, respectively). There is the same incidence of inflammatory placental lesions in patients with preterm labour and facultative-pathogenic micro-organisms in the vagina and/or in the canal of the cervix who received adjuvant antibiotic treatment during pregnancy compared with patients who were treated vaginally with polyvidone-iodine.

Administration, Intravaginal↗
PubMed1983

[Reading epilepsy].

Reading epilepsy in many cases may be identified by clicking sensations or myoclonic jaw jerks, which are supposed to be prodromal symptoms to generalized epileptic convulsions. Although these prodromal symptoms were considered as characteristic by the first authors describing the illness, they were not observed in all the published cases. In this paper a modified classification following the original proposal of Bickford is suggested. It is now proposed to differentiate a primary specific respectively nonspecific form from a secondary type. Most of the cases described were between 15 and 28 years of age. Probably the disorder is only of transient nature. The pathogenic roots are multifactorial, and the seizures cannot be attached to typical focus-regions. Decoding mechanisms and disorders of speech as sensoric restraints are obviously of great importance in actual provocation.

Adolescent↗
PubMed2006

Cloning, crystallization and preliminary X-ray study of XC1258, a CN-hydrolase superfamily protein from Xanthomonas campestris.

CN-hydrolase superfamily proteins are involved in a wide variety of non-peptide carbon-nitrogen hydrolysis reactions, producing some important natural products such as auxin, biotin, precursors of antibiotics etc. These reactions all involve attack on a cyano or carbonyl carbon by a conserved novel catalytic triad Glu-Lys-Cys through a thiol acylenzyme intermediate. However, classification into the CN-hydrolase superfamily based on sequence similarity alone is not straightforward and further structural data are necessary to improve this categorization. Here, the cloning, expression, crystallization and preliminary X-ray analysis of XC1258, a CN-hydrolase superfamily protein from the plant pathogen Xanthomonas campestris (Xcc), are reported. The SeMet-substituted XC1258 crystals diffracted to a resolution of 1.73 A. They are orthorhombic and belong to space group P2(1)2(1)2, with unit-cell parameters a = 143.8, b = 154.63, c = 51.3 A, respectively.

Amino Acid Sequence↗
PubMed2006

FT-IR microspectroscopy for early identification of some clinically relevant pathogens.

AIMS: To investigate the potentials and limitations of Fourier transform-infrared (FT-IR) microspectroscopy as a tool to identify, at the level of microcolonies, pathogenic bacteria frequently isolated in the clinical environment. METHODS AND RESULTS: A total of 1570 FT-IR spectra from 164 gram-positive and gram-negative bacteria isolated from patients were recorded from 6 to 10-h old microcolonies of 50-150 microm size. A classification of 100% was obtained for the most frequent gram-positive bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Enterococcus faecium at the species level. An average accuracy of about 80% was reached with Gram negative bacteria from the Enterobacteriaceae and Pseudomonaceae families; Enterobacter aerogenes, Enterobacter cloacae, Klebsiella spp., and Citrobacter koseri; and Proteus mirabilis and Escherichia coli. Results were comparable with FT-IR measurements on dried suspensions from 18-h cultures. CONCLUSIONS: Early identification of young microcolonies is feasible with FT-IR microscopy with a very high accuracy for gram-positive bacteria. Some improvement in the transfer of microcolonies is necessary to increase the accuracy for gram-negative bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Combination of FT-IR microscopy and multivariate data analysis could be a complementary, rapid, and reliable tool for screening and discriminating, at species and subspecies level, micro-organisms of clinical, food-borne, or environmental origins.

Animals↗
PubMed1976

The predominant cultivable organisms in juvenile periodontitis.

Quantitative and qualitative examinations of the predominant cultivable microflora of the advanced tissue destruction (pocket) associated with juvenile periodontitis and of control pockets without loss of attachment were carried out by using anaerobic tube culture technique. The microflora from the control sites consisted primarily of streptococci, Gram-negative rods, and Gram-positive rods. In contrast, the test pockets had a relatively stable and characteristic microflora, dominated by various Gram-negative, anaerobic rods. The Gram-negative rods were divided into main groups, but a satisfactory classification of many of these microorganisms could not be performed with the methods used and the data available. The predominating Gram-negative rods differed from individual to individual. The role of the Gram-negative rods in the etiology of juvenile periodontitis is unknown. Some potential pathogenic mechanisms of these microorganisms are discussed.

Actinomyces↗
PubMed2005

Genomic and proteomic profiling of lung cancers: lung cancer classification in the age of targeted therapy.

Both proteomic and genomic methods offer promise for the classification of human lung carcinomas. This review summarizes the range of proteomic methods in development for lung cancer classification, and describes a number of recent analyses of messenger RNA expression in lung cancer. Multiple independent studies of mRNA expression profiles in lung adenocarcinoma have proven highly reproducible. Analyses of the relationship between expression profiles and tumor development and differentiation, the presence or absence of specific pathogenic mutations, patient prognosis and survival after surgical treatment, and specific histopathology all appear to be promising.

Gene Expression Profiling↗
PubMed1998

Classification of the genus Legionella.

There are currently 42 described species of legionellae representing 64 serogroups in the family Legionellaceae and the genus Legionella. The phenotypic characteristics of legionellae are described, including growth requirements, and biochemical characteristics. Identification of legionellae by biochemical tests, fatty acid analysis, ubiquinones, protein profiles, carbohydrate analysis, serology, monoclonal antibodies, and molecular techniques is described. The occurrence and description of Legionella-like amebic pathogens are discussed. The problems of identification to the species level are discussed, along with the need for further evaluations of additional strains from all known species using biochemical and molecular techniques.

Humans↗
PubMed2006

Dominulin A and B: two new antibacterial peptides identified on the cuticle and in the venom of the social paper wasp Polistes dominulus using MALDI-TOF, MALDI-TOF/TOF, and ESI-ion trap.

Two new antibacterial peptides, denominated as Dominulin A and B, have been found on the cuticle and in the venom of females of the social paper wasp Polistes dominulus. The amino acidic sequence of the two peptides, determined by mass spectrometry, is INWKKIAE VGGKIL SSL for Dominulin A (MW = 1854 Da) and INWKKIAEIGKQVL SAL (MW = 1909 Da) for Dominulin B. Their presence on the cuticle was confirmed using MALDI-TOF by means of micro-extractions and direct analyses on body parts. The presence in the venom and the primary structure of the dominulins suggest their classification in the mastoparans, a class of peptides found in the venom of other Aculeate hymenoptera. Their antimicrobial action against Gram+ and Gram- bacteria fits in the range of the best natural antimicrobial peptides. Dominulins can represent an important defense of the colony of Polistes dominulus against microbial pathogens.

Amino Acid Sequence↗
PubMed1996

Extracellular and surface-exposed polysaccharides of non-tuberculous mycobacteria.

We studied the outermost constituents of the cell envelopes, which are involved in the interaction between the bacilli and the host cells, of five pathogenic and non-pathogenic mycobacterial species for comparison with those we have previously characterized from M. tuberculosis. The extracellular materials (ECMs) were isolated by ethanol precipitation and compared to the surface-exposed materials (SXMs) extracted by mechanical means. The materials from both sources were composed almost exclusively of polysaccharides and proteins. Two groups of mycobacteria were clearly distinguishable. The first group comprised the pathogenic species M. kansasii which produced large amounts of ECM, the glycosyl composition of which was similar to that of the SXM. The second group comprised M. avium and the non-pathogenic strains of M. gastri, M. phlei and M. smegmatis which produced small amounts of ECK This latter group could be subdivided into those which produced carbohydrate-rich ECM (M. avium and M. gastri) and those forming protein-rich ECM (M. phlei and M. smegmatis), a classification that correlated with the difference in the growth rate of the two subgroups. The glycosyl composition of the ECM of a given species was qualitatively similar to that of the SXM, except for M. avium and M. phlei whose SXM were devoid of arabinose. In addition to glucose, mannose and arabinose, xylose was detected in the hydrolysis products of the ECM and SXM of M. smegmatis, the SXM of M. phlei and the ECM of some batches of M. avium. The polysaccharide constituents of the ECM and SXM of the different mycobacteria were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. The extracellular polysaccharides consisted of high-molecular-mass glycogen-like glucans, arabinomannans and mannans, structurally similar to the corresponding substances previously characterized from the capsule of M. tuberculosis. The same types of polysaccharides were characterized from the SXM of all the strains, except M. avium and M. phlei which were devoid of arabinomannans. This study questions the unique and universal representation of the mycobacterial cell envelope and the existence of the so-called acidic polysaccharide-rich outer layer.

Antigens, Bacterial↗
PubMed2004

Reconsideration of Arthrobacter ilicis (Mandel et al. 1961) Collins et al. 1982 as a plant-pathogenic species. Proposal to emend the authority and description of the species. Request for an opinion.

Strains now considered to represent the type strain of Arthrobacter ilicis, described as a pathogen of American holly, are not identical. The designated type strain does not represent this pathogen. However, one of the other strains sourced to the type strain of the pathogen does appear to be authentic, but is not a member of A. ilicis. It is proposed that A. ilicis is an unrelated species, not a pathogen of American holly. The nomenclature of A. ilicis can be rectified by emending the authority and by emending the species description to recognize this species as a novel species that is not a plant pathogen. The pathogen of American holly then becomes a novel pathovar, Curtobacterium flaccumfaciens pv. ilicis. The opinion of the Judicial Commission is sought.

Arthrobacter↗
PubMed2002

The spectrum of vasculitis in children.

The common vasculitides of childhood are more self-limited than those in adults. Clinical evidence suggests that infectious agents may have a significant role in the aetiology of these diseases although exact pathogenic mechanisms are not known. One of the most frequent of such diseases in childhood is Henoch-Schönlein purpura. The controversies regarding the management of gastrointestinal and renal disease and suggested treatments are reviewed. The limitations of current definitions for polyarteritis nodosa are discussed and a new classification tree for this disease is introduced. The definitions and classification criteria for the other major vasculitides encountered in children are also presented. Current treatment protocols for polyartertis nodosa, Wegener's granulomatosis and Behcet's disease are summarized.

Behcet Syndrome↗
PubMed2004

Gas gangrene and necrotizing fasciitis in the upper extremity.

Necrotizing soft tissue infections encompass a wide variety of clinical syndromes resulting from introduction of various pathogens into injured or devitalized tissue. The extent of microbial involvement in such tissue may range from simple contamination to overt and progressive local tissue necrosis, which, if untreated, may lead to septicemia and death. Early differentiation among these infections is not always possible, as there are overlapping classification criteria. These infections exist along a continuum of clinical severity with different etiological agents and associated medical conditions. The often subtle clues heralding the presence of a necrotizing soft tissue infection must be sought so that expeditious surgical debridement and broad-spectrum antibiotic management are initiated. Although experience enables the clinician to make a specific diagnosis based on early findings, aggressive and proper treatment of suspected infections remains the priority. The purpose of the article is to provide an overview of necrotizing soft tissue infections in the upper extremity, focusing on gas gangrene, or clostridial myonecrosis, and necrotizing fasciitis, to facilitate early diagnosis and optimal management of these lethal diseases.

Cellulitis↗