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Results for “pathogenicity classification”

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PubMedDate not supplied

Classification, pathogenicity, and drug susceptibility of hemolytic gram-negative bacteria isolated from sick or dead chickens.

Fifteen hemolytic gram-negative bacteria were isolated from the respiratory tracts of sick birds suffering from a long-lasting respiratory syndrome or from the bone marrow of dead birds distributed in the southern part of Taiwan. These were classified as Pseudomonas aeruginosa (10 isolates), Pseudomonas fluorescens (2 isolates), Pseudomonas stutzeri (1 isolate), Pasteurella haemolytica (1 isolate), and Proteus morganii (1 isolate). Each isolate was inoculated intraperitoneally into one group of ten 4-week-old male white leghorn chickens. Mortality and lesions were scored daily for 1 week. Three of the 10 isolates of Pseudomonas aeruginosa caused 100% mortality. Six other isolates of Pseudomonas aeruginosa and the one isolate of Proteus morganii caused 50% mortality. The remaining isolates induced less than 30% mortality. The sole nonpathogenic sample was one isolate of Pseudomonas fluorescens. When therapeutic levels of 22 antibiotics or sulfa drugs were evaluated for their inhibitory activity against the 15 isolates, the most effective were apramycin (15/15), gentamicin (15/15), spectinomycin (13/15), oxytetracycline (8/15), and sulfachloropyrazine (7/15). The least effective were ampicillin, cloxacillin, and tiamulin, which were not effective against any of the isolates. The 14 other drugs were of very low (> 4/15) effectiveness. Most of the isolates studied were virulent for chickens and very resistant to currently used drugs.

Animals↗
PubMed2006

[Senile retinoschisis with tearing of the deep layer--classification and pathogenic hypotheses].

The observations have been made on 52 eyes with senile retinoschisis with tearing of the deep layer. These principle studies are the aspect of tearing, in order to classify and discuss the pathogenic hypotheses. Seven types of tearing are presented. Their modes of formation seem different. We established a pathogenic classification of these tears. The risk of operation on a secondary retinal detachment is always a subject of discussion even if the symptomatic detachment may be considered very rare. From these seven observation of schisis detachment, there is proposed a pathogenic hypothesis. The vitreous have played the principal role in making a traction on the edge of the deep tears where sometimes the retinoschisis is not formed. It is recommended to observe and analyse systematically the tearing of the retinoschisis external layer.

Aged↗
PubMed1997

The value of Hughes-Cardiff classification in the management of perianal Crohn's disease.

PURPOSE: The aim of this study was to assess the value of Hughes' pathogenic classification in the prognosis and management of perianal Crohn's disease (CD). PATIENTS AND METHODS: This classification differentiates between purely inflammatory lesions and their mechanical or septic complications, and defines the presence of ulceration (U), fistula (F) and stricture (S), which are assigned a score of 0, 1 or 2 according to the severity and associated conditions, proximal intestinal involvement and disease activity (A, P and D). Of a series of 96 patients with CD, 12 underwent 16 procedures involving anesthesia to treat symptomatic anal lesions. Patients presenting with severe pain were explored and treated by surgical drainage or, in cases in which there was no demonstrable sepsis, by gentle dilation or infiltration with steroids. For superficial, non-specific fistulas, conventional fistulotomy was performed, and long-term seton drainage was implanted for complex fistulas. Strictures were treated by gentle dilation. Uncontrolled sepsis or proctocolitis was managed by proximal stoma creation or proctocolectomy. RESULTS: The association of cavitating ulcers (U2) and contiguous active rectal involvement (P1) was a contraindication for rectal preservation, making proctectomy or stoma creation the most feasible therapeutic option. The etiology of most, but not all, complex fistulas (F2) was the progressive cavitation of U2, whilst F1 was either of cryptoglandular origin or the result of epithelialized fissures (U1). The treatment was also adjusted to this association, and it was confirmed that most of the severe lesions (F2) and S2) were secondary to U2. CONCLUSIONS: Hughes' pathogenic classification: 1) makes it possible to set up an easily stored registry of anal and perianal Crohn's disease; 2) identifies predefined lesions, allowing the individualization of therapeutic procedures and the comparison of results, and 3) provides prognostic information.

Adolescent↗
PubMed2006

Multilocus sequence typing method for identification and genotypic classification of pathogenic Leptospira species.

BACKGROUND: Leptospira are the parasitic bacterial organisms associated with a broad range of mammalian hosts and are responsible for severe cases of human Leptospirosis. The epidemiology of leptospirosis is complex and dynamic. Multiple serovars have been identified, each adapted to one or more animal hosts. Adaptation is a dynamic process that changes the spatial and temporal distribution of serovars and clinical manifestations in different hosts. Serotyping based on repertoire of surface antigens is an ambiguous and artificial system of classification of leptospiral agents. Molecular typing methods for the identification of pathogenic leptospires up to individual genome species level have been highly sought after since the decipherment of whole genome sequences. Only a few resources exist for microbial genotypic data based on individual techniques such as Multiple Locus Sequence Typing (MLST), but unfortunately no such databases are existent for leptospires. RESULTS: We for the first time report development of a robust MLST method for genotyping of Leptospira. Genotyping based on DNA sequence identity of 4 housekeeping genes and 2 candidate genes was analyzed in a set of 120 strains including 41 reference strains representing different geographical areas and from different sources. Of the six selected genes, adk, icdA and secY were significantly more variable whereas the LipL32 and LipL41 coding genes and the rrs2 gene were moderately variable. The phylogenetic tree clustered the isolates according to the genome-based species. CONCLUSION: The main advantages of MLST over other typing methods for leptospires include reproducibility, robustness, consistency and portability. The genetic relatedness of the leptospires can be better studied by the MLST approach and can be used for molecular epidemiological and evolutionary studies and population genetics.

Animals↗
PubMed1998

In vitro and rapid in situ transglutaminase assays for congenital ichthyoses--a comparative study.

Autosomal recessive congenital ichthyoses are a heterogeneous group of disfiguring skin diseases. They are generally characterized by variable scaling and erythroderma, and patients are frequently collodion babies at birth. Autosomal recessive congenital ichthyoses are represented in 25 of our 50 families by a defective keratinocyte transglutaminase (TGK). Pathogenic classification is difficult to assess on clinical grounds for autosomal recessive congenital ichthyoses and impossible for collodion babies. Thus, we have established a rapid TGK assay in situ on frozen skin sections using incorporation of dansyl-cadaverin to assess transglutaminase (TG) activity in combination with immunohistochemistry for TGK protein. Results were compared with TG activity levels measured in cultured differentiating keratinocytes. Sixteen of 26 patients, including a collodion baby, had strongly diminished TG activity in the cell periphery of differentiating keratinocytes and membrane-bound TG activities in vitro, ranging from 2.2 to 281.3 pmol per h mg. Nine of 26 patients, including a collodion baby, showed strong TG activity in the cell periphery of differentiating keratinocytes in situ and membrane-bound TG activities in vitro ranged from 1519 to 10917 pmol per h mg. In one case, TG assay in situ was ambiguous; however, membranous TG activity in vitro was very low at 76.9 pmol/h x mg. Our results demonstrate an excellent correlation of TG assays in vitro and in situ. In addition, we present a novel test with prognostic value for the collodion baby phenotype. This assay allows rapid pathogenic classification of autosomal recessive congenital ichthyoses with only one caveat that in rare ambiguous cases it might be necessary for proper classification to assess membrane-bound TG activity in vitro.

Animals↗
PubMedDate not supplied

Classification of pathogenic Escherichia coli according to serotype and the production of virulence factors, with special reference to colonization-factor antigens.

Multiple criteria are required to classify Escherichia coli isolates according to pathogenic grouping. There are three groups associated with intestinal illness. Acute watery diarrhea is the hallmark of enterotoxigenic E. coli, the majority of which belong to a small set of specific serotypes harboring plasmids encoding for the production of heat-stable enterotoxin and/or heat-labile enterotoxin and also for a fimbrial colonization-factor antigen. Bacterial dysentery is caused by specific, nonmotile Shigella-like E. coli serogroups identifiable by the property of tissue invasiveness. Specific virulence factors have not been defined for the traditional enteropathogenic E. coli serogroups, although the ability to colonize and overgrow the intestine appears to be of primary importance in this group. E. coli associated with extraintestinal infections generally belong to serogroups and serotypes other than those noted above; the virulence factors of these E. coli include polysaccharide capsular antigens, hemolysin, and fimbrial colonization factors that are antigenically complex and different from those of the enterotoxigenic E. coli.

Adhesiveness↗