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PubMed2005

ProLysED: an integrated database and meta-server of bacterial protease systems.

UNLABELLED: Bacterial proteases are an important group of enzymes that have very diverse biochemical and cellular functions. Proteases from prokaryotic sources also have a wide range of uses, either in medicine as pathogenic factors or in industry and therapeutics. ProLysED (Prokaryotic Lysis Enzymes Database), our meta-server integrated database of bacterial proteases, is a useful, albeit very niche, resource. The features include protease classification browsing and searching, organism-specific protease browsing, molecular information and visualisation of protease structures from the Protein Data Bank (PDB) as well as predicted protease structures. AVAILABILITY: ProLysED is integrated into the ProLysES (Prokaryotic Lysis Enzymes Site) website at http://genome.ukm.my/prolyses/. Access to the ProLysED database is free for academic users upon registration.

Amino Acid Sequence↗
PubMed2001

[Adult T-cell leukemia/lymphoma. Clinical aspects].

BACKGROUND DATA: Adult T-cell leukemia/lymphoma (ATL) is a malignant proliferation of activated CD4+ T lymphocytes. The disease is almost exclusively found in patients living in retrovirus HTLV-1 endemic areas. VIROLOGY: In ATL, monoclonal HTLV-1 provirus is integrated into atypical lymphocytes, called clover-leaf lymphocytes. The pathogenic mechanism leading to HTLV-1-induced leukemogenesis remains obscure. The disease generally occurs after a long latency period. FOUR CLINICAL SUBTYPES: The diversity of the clinical presentation has led to the classification of ATL into four subtypes: acute or prototype, lymphoma, chronic, and painless. In the acute form of ATL there is a tumor syndrome associated with paraneoplastic hypercalcemia and a high rate of opportunistic infections due to the immunodepression predominated by cellular immunity. CLINICAL COURSE: Prognosis is poor for the acute and lymphomatous forms with a median survival of 6 and 10 months respectively. Infectious episodes are frequent, often caused by Pneumocystis carinii, and require systematic prophylaxis. Screening for anguilulosis and prophylaxis is also necessary.

Adult↗
PubMedDate not supplied

[The subspecies specificity of Babesia canis].

The large Babesia species of dogs, Babesia canis, is transmitted by different ticks. Dermacentor reticulatus, Rhipicephalus sanguineus and haemaphysalis leachi are the known main vectors. Four B. canis isolates of different geographic origin were investigated for their transmission specificity and pathogenicity in infection trials. R. sanguineus ticks exclusively transmitted the Babesia isolate from Egypt. D. reticulatus was the vector for isolates from Hungary and France. Transmission of an South-African isolate was only possible by H. laechi. The B. canis isolates differed markedly in their pathogenicity. The South-African isolate was highly pathogenic and resulted in nearly complete mortality. Infections with the isolate from Hungary transmitted by D. reticulatus, also resulted in severe clinical disease which often ended fatal without treatment with an anti-Babesia drug. Clinical disease also resulted from infections with the French isolate while the isolate from Egypt was largely non-pathogenic. Challenge trials for investigations of cross-immunity demonstrated immunogenic differences between the individual isolates. The degree of immunogenicity appeared to be related to the pathogenicity of the Babesia isolates. Serological investigations revealed that antigen of the isolate from Hungary in ELISA reacted markedly higher than the other three antigens. Due to their vector specificity B. canis classification into three groups is possible: B. canis canis transmitted by D. reticulatus, B. canis vogeli transmitted by R. sanguineus and B. canis rossi transmitted by H. laechi.

Animals↗
PubMed1997

A novel pathogenic taxon of the Mycobacterium tuberculosis complex, Canetti: characterization of an exceptional isolate from Africa.

In an attempt to characterize an unusual mycobacterial strain isolated from a 2-year-old Somali patient with lymphadenitis, we applied various molecular methods not previously used for the taxonomic classification of mycobacteria. This isolate, designated So93, did not differ from Mycobacterium tuberculosis in the biochemical tests and in its 16S rRNA sequence, but produced smooth and glossy colonies, which is highly exceptional for this species. This smooth phenotype was unstable and switched nonreversibly to a rough colony morphology with a low frequency. The two colony types were equally virulent for the guinea pig, exhibiting characteristic tuberculous disease. Both morphotypes had shorter generation times than the M. tuberculosis reference laboratory strain H37Rv and clinical isolates of M. tuberculosis and Mycobacterium bovis. Furthermore, the So93 isolate differed from all M. tuberculosis complex strains described thus far by having only a single copy of insertion sequence IS1081, an unusual composition of the direct repeat cluster, and a characteristic phenolic glycolipid and lipooligosaccharide. This glycolipid had previously been observed only in a smooth isolate of M. tuberculosis obtained in 1969 by Canetti in France. Analysis of the Canetti strain showed that it shared virtually all genetic properties characteristic of So93, distinguishing these two strains from the known M. tuberculosis complex taxa, M. tuberculosis, Mycobacterium africanum, M. bovis, and Mycobacterium microti. The natural reservoir, host range, and mode of transmission of the group of bacteria described in this paper are presently unknown. This study, partly based on not previously used molecular criteria, supports the idea that the established members within the M. tuberculosis complex and the newly described Canetti grouping should be regarded as a single species, which likely will be designated "M. tuberculosis".

Animals↗
PubMed2005

Mitochondrial encephalomyopathies: an update.

A genetic classification of the mitochondrial encephalomyopathies includes disorders due to defects of mitochondrial DNA (mtDNA) and disorders due to defects of nuclear DNA (nDNA). Recent progress in mtDNA-related diseases includes: (i) new pathogenic mutations in protein-coding genes, especially those encoding subunits of complex I (ND genes); (ii) the pathogenic nature of homoplasmic mutations, whose expression is regulated by environmental and genetic factors; (iii) increasing interest in the functional and pathophysiological role of haplotypes. Advances in mendelian mitochondrial diseases include: (i) new mutations in genes for complex I subunits; (ii) identification of new mutant ancillary proteins associated with complex IV and complex V deficiencies; (iii) better molecular understanding of disorders due to faulty intergenomic communication, which are associated with multiple mtDNA deletions, mtDNA depletion, or defects of mtDNA translation; (iv) the pathogenic role of alterations of the inner mitochondrial membrane phospholipid components, especially cardiolipin; (v) the emerging importance of defects in mitochondrial motility, fission, or fusion.

DNA, Mitochondrial↗
PubMed1997

Classification and epidemiology of the vasculitides.

The systemic vasculitides are rare inflammatory conditions of blood vessel walls. A number of different classification schemes have been published since the first in 1952. The important developments have been the recognition of dominant blood vessel size, the distinction between primary and secondary vasculitis and the incorporation of pathogenic markers such as anti-neutrophil cytoplasmic antibodies. In 1990 the American College of Rheumatology (ACR) published criteria for the diagnosis of polyarteritis nodosa, Churg-Strauss syndrome, Wegener's granulomatosis, hypersensitivity vasculitis, Schönlein-Henoch purpura, giant cell arteritis and Takayasu arteritis. Sensitivity and specificity rates varied considerably: 71.0-95.3% for sensitivity and 78.7-99.7% for specificity. The criteria were not tested against the general population or against patients with other connective tissue diseases or rheumatic conditions. Four years later the Chapel Hill Consensus Conference (CHCC) produced definitions for the major types of vasculitis, however, these have proved controversial. Comparison in unselected patients with systemic vasculitis (in particular polyarteritis nodosa and microscopic polyangiitis) has shown that the ACR criteria and CHCC definitions identify different patients. The systemic vasculitides are somewhat more common than previously believed. The overall annual incidence approaches 40/million adults. The most common form of primary systemic vasculitis is giant cell arteritis; Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome have similar incidences. Classical polyarteritis nodosa and Takayasu arteritis are very rare in the UK.

Humans↗
PubMed1998

Orbital infections and inflammations.

Orbital infections and inflammations present to the clinician with similar findings: periorbital edema, erythema, proptosis, and pain. History and clinical examination determine the work-up required to better define the disease process. Orbital infections continue to be associated primarily with diseases of the paranasal sinuses. Haemophilus influenza type B is no longer a significant pathogen, because of an effective vaccine. Fungal infections extending to the orbit are becoming more frequent due to the prevalence of immunocompromised patients. Orbital inflammations continue to be poorly understood, and an adequate classification scheme does not exist. Corticosteroids continue to be the preferred initial treatment, with the roles of radiation and nonsteroidal antiinflammatory medications to be determined. Specific causes of orbital inflammation such as Wegener granulomatosis must be considered to prevent potentially life-threatening complications.

Cellulitis↗
PubMed1999

[Monitoring of parasites in domestic sewage].

OBJECTIVE: The evaluation of the presence of parasites in semisolid and liquid sewage in Argentinian Patagonia in view of the fact that this is a restriction for its use. METHODS: The samples taken at 4 Domestic Sewage Plants were analyzed in accordance with Standard Methods for the Examination of Water and Wastewater, Environmental Protection Agency, World Health Organization and some other classifications. RESULTS: Only 2 of 6 semisolid samples analyzed had non-viable Ascaris lumbricoides eggs. Of the 10 liquid samples analyzed, only 2 did not contain eggs whereas the remaining ones had pathogens of categories I (Giardia sp., Hymenolepis nana and Enterobius vermicularis) and III (Ascaris lumbricoides, Ancylostoma duodenale and Trichuris trichiura). CONCLUSIONS: All semisolid samples turned out to be satisfactory for use as fertilizer as no viable Ascaris lumbricoides eggs were found in any of them. But only 6 of the liquid samples were satisfactory for use as they had no eggs or their concentrations was equal to or less than 1 egg per litre.

Animals↗
PubMed2000

Severe invasive group A beta-hemolytic streptococcus infection complicating pharyngitis: a case report and discussion.

Group A beta-hemolytic streptococcus (GABHS) has long been recognized as a deadly pathogen with manifestations ranging from impetigo to necrotizing fasciitis. Bacteremia from streptococcal pharyngitis is a rare complication. We report a patient presenting with septic shock and diabetic ketoacidosis from streptococcal pharyngitis. The pathophysiology, classification, and treatment of invasive group A streptococcal infection is discussed.

Adult↗
PubMed1998

Mycobacterium xenopi in HIV-infected patients: an emerging pathogen.

BACKGROUND: Mycobacterium xenopi is associated with pulmonary disease in patients with loss of local or general host defence. OBJECTIVES: To determine the occurrence of M. xenopi in our hospital during 1987-1992 and 1993-1996, as well as the association of M. xenopi with HIV infection in 1993-1996; to evaluate the clinical significance of M. xenopi in HIV-seropositive patients. DESIGN: Retrospective review of charts and classification of patients based on earlier definitions derived from the American Thoracic Society. SETTING: Tertiary hospital. PATIENTS: Patients with a positive isolate of M. xenopi from January 1987 until December 1996. MAIN OUTCOME MEASURES: During 1993 1996, a significant increase in the number of patients with M. xenopi was found compared with 1987-1992. Of 25 patients, 22 were HIV-seropositive. RESULTS: The HIV-seropositive patients were classified as having definite (n = 5), probable (n = 9) and unlikely disease (n = 8) due to M. xenopi. Symptoms, median CD4 cell count, treatment and outcome did not differ between these groups. CONCLUSIONS: M. xenopi is an emerging pathogen, especially in HIV-infected patients. The criteria of the American Thoracic Society for disease due to non-tuberculous mycobacteria do not seem applicable to M. xenopi in HIV-infected patients. We suggest that two positive cultures of M. xenopi and no other likely cause of symptoms present should be considered the criteria for diagnosis of M. xenopi disease in HIV-infected patients.

Adult↗
PubMedDate not supplied

[Biological features and experimental pathogenicity of Candida strains isolated by hemoculture at the Hospital Infantil de México "Federico Gómez"].

In a period of 15 months (1990-1991) it was carried out 5781 blood cultures in which 180 strains of yeast-like were isolated. 116 of these strains were selected for biochemical classification, cellular and colonial morphology and experimental determination of virulence in mice. Most of the strains were classified as Candida albicans (60%) and the others were C. tropicalis (15.5%); C. guillermondii (10.3%); T. glabrata (6.8%); Rhodotorula rubra (3.4%); Cryptococcus neoformans (2.58%) y C. parapsilosis (0.86%). C. albicans ATCC14053, y C. tropicalis ATCC14056 and T. glabrata ATCC15545 were employed as controls. The virulence test was performed using mice of 20-30 gr (4-6 weeks age) by intravenous injection in caudal vein with 0.5 ml of different suspension from 10(5) to 10(9) CFU/ml. Observation time was 10 days. Target organ was kidney by macro and microscopic observation of micro-abscess death. LD50 was estimated by the Reed-muench method. Intraspecific and interspecific differences were observed. It is more valid if we take into account that the experiment was done in homogenous population of host without risk factor which influences the human population in hospitals. Experimental virulence was compared with the evolution of diseases in the human host of which the strain was isolated.

Blood↗
PubMed2005

[Methods for population-based herd sanitation: an overview].

There is a considerable number of methods available for the development, maintenance and surveillance of specific-pathogen-free herds. The selection of a method for a specific remediation project is primarily dependent on the goal, the epidemiology of the agent to be eradicated, the feasibility and the available resources. At the beginning of the remediation programme, methods are required for the classification of the herd status. Clinical and analytical diagnostic tests may be used for individual herds or in an entire area. The interpretation of test results applied within a population deserves special attention. A series of techniques are available - alone or in combination - to remediate a herd that was classified as being infected: systematic treatment, vaccination, elimination of infected individual animals ("test and remove"), partial depopulation or total population (stamping out). These strategies are typically accompanied by cleaning and disinfection. After the remediation, the status of the herd needs to be certified and maintained. For the documentation of the status, monitoring and surveillance strategies such as clinical follow-up visits, notification systems and random sampling can be applied. When planning random surveys, statistical and epidemiological considerations are relevant. For the sustainable maintenance of the pathogen-free status, biosecurity measures at the individual farm level, but also broader approaches such as import restrictions, early warning systems and surveillance programmes are needed. General awareness regarding unusual clinical signs needs to be promoted among farmers and veterinarians. The longer a disease or an agent is absent from a herd or region, the lower becomes the risk awareness. In such a situation, mistakes can occur leading to an increased risk of re-infection.

Animal Diseases↗
PubMed1992

Safe biotechnology (4). Recommendations for safety levels for biotechnological operations with microorganisms that cause diseases in plants.

The Working Party on Safety in Biotechnology of the European Federation of Biotechnology has proposed a classification of microorganisms that cause diseases in plants. In this paper appropriate safety levels are proposed for these classes of microorganisms in order to ensure that research, development and industrial fermentation work with plant pathogens will limit the risk of outbreaks of diseases in crops that could result from work with such microorganisms when they are cultivated in laboratories, glasshouses and biotechnology installations.

Containment of Biohazards↗
PubMed2006

A Bartonella vinsonii berkhoffii typing scheme based upon 16S-23S ITS and Pap31 sequences from dog, coyote, gray fox, and human isolates.

Since the isolation of Bartonella vinsonii subspecies berkhoffii from a dog with endocarditis in 1993, this organism has emerged as an important pathogen in dogs and as an emerging pathogen in people. Current evidence indicates that coyotes, dogs and gray foxes potentially serve as reservoir hosts. Based upon sequence differences within the 16S-23S ITS region and Pap31 gene, we propose a classification scheme that divides B. vinsonii subsp. berkhoffii isolates into four distinct types. Two conserved sequences, of 37 and 18 bp, respectively, are differentially present within the ITS region of each of the four B. vinsonii subsp. berkhoffii types. To date, B. vinsonii berkhoffii types I, II, and III have been identified in the US, type III in Europe and type IV in Canada. Based upon the proposed genotyping scheme, the geographic distribution of B. vinsonii berkhoffii types needs to be more thoroughly delineated in future molecular epidemiological studies involving Bartonella infection in coyotes, dogs, gray foxes, human beings and potentially other animals or in arthropod vectors. Strain typing may help to better define the reservoir potential, carriership patterns, modes of transmission, and geographic distribution for each B. vinsonii berkhoffii type.

Animals↗
PubMedDate not supplied

The conjunctival lymphoid follicle in mucosal immunology.

The conjunctiva forms a continuous mucosal surface from the eyelid margin to the cornea, and makes contact with airborne antigens and those on the adjacent eyelid skin and preocular tear film. Conjunctival lymphoid follicles (CLF) undergo hyperplasia upon conjunctival infection by a specific array of pathogens; infection-associated enlargement of draining preauricular lymph nodes suggests that CLF participate in the afferent limb of acquired immune responses for the ocular surface. In this review, we examine the evidence for classification of CLF as part of the common mucosal immune system, and explore the possible therapeutic implications.

Animals↗
PubMed2005

Treatment of infections with ESBL-producing organisms: pharmacokinetic and pharmacodynamic considerations.

Susceptibility surveillance investigations have demonstrated an increased incidence of ESBL-producing Gram-negative bacilli. Case cohort studies have suggested clinical relevance associated with ESBL-producing Enterobacteriaciae infection. Yet, current laboratory reporting guidelines classify a large percentage of these organisms in the susceptible category. The regulatory agencies Clinical Laboratory Standards Institute (formly NCCLS) and EUCAST, which oversee these guidelines are in the process of re-evaluating the appropriateness of the current classification system. Pharmacokinetic and pharmacodynamic studies examine the relationship between drug exposure (pharmacokinetics), antibiotic potency (MIC), and treatment efficacy. PK/PD studies and analyses have been useful in demonstrating the relevance of increasingly less susceptible pathogens and specific emerging resistance mechanisms. Recent investigations have examined the impact of ESBL-producing Gram-negative bacilli relative to advanced generation cephalosporin pharmacokinetics. Animal model studies suggest that the pharmacodynamic target associated with efficacy in treatment of ESBL-producing organisms is the same as that in therapy against non-ESBL-producing bacteria (50% T>MIC). Simulation of human pharmacokinetics can predict the likelihood of achieving this PD target with specific cephalosporin dosing regimens. In general, the exposure from usual regimens of the advanced generation cephalosporins would not be anticipated to achieve the PD target for many of the organisms currently classified as susceptible. PK/PD analyses should be useful in re-evaluating current susceptibility breakpoints for ESBL-producing organisms and for optimising drug and regimen choice in treatment of these infections.

Animals↗
PubMed1995

Microorganism gram-type differentiation based on pyrolysis-mass spectrometry of bacterial Fatty Acid methyl ester extracts.

Curie-point pyrolysis (Py)-mass spectrometry has been used to differentiate 19 microorganisms by Gram type on the basis of the methyl esters of their fatty acid distribution. The mass spectra of gram-negative microorganisms were characterized by the presence of palmitoleic acid (C(inf16:1)) and oleic acid (C(inf18:1)), as well as a higher abundance of palmitic acid (C(inf16:0)) than pentadecanoic acid (C(inf15:0)). For gram-positive microorganisms, a signal of branched C(inf15:0) (isoC(inf15:0) and/or anteisoC(inf15:0)) more intense than that of palmitic acid was observed in the mass spectra. Principal components analysis of these mass spectral data segregated the microorganisms investigated in this study into three discrete clusters that correlated to their gram reactions and pathogenicities. Further tandem mass spectrometric analysis demonstrated that the nature of the C(inf15:0) fatty acid isomer (branched or normal) present in the mass spectrum of each microorganism was important for achieving the classification into three clusters.

Journal Article↗
PubMed1994

Ectoparasites and classification.

The authors present an introductory overview of the principal groups of ectoparasites (flukes, leeches, crustaceans, insects, arachnids, lampreys and vampire bats) associated with domestic animals. Currently-accepted higher-level classifications are outlined for these parasites. Almost all significant ectoparasites of domestic animals are invertebrates, the majority being arthropods (crustaceans, insects and arachnids). Some of these ectoparasites are of particular importance as vectors of pathogens. Many ectoparasite species are host-specific, and vector species typically transmit characteristic pathogens.

Animals↗