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At least 1,459 records · Page 81Linked to original sources
PubMed2004

Immune-deficient Drosophila melanogaster: a model for the innate immune response to human fungal pathogens.

We explored the host-pathogen interactions of the human opportunistic fungus Candida albicans using Drosophila melanogaster. We established that a Drosophila strain devoid of functional Toll receptor is highly susceptible to the human pathogen C. albicans. Using this sensitive strain, we have been able to show that a set of specific C. albicans mutants of different virulence in mammalian infection models are also impaired in virulence in Drosophila and remarkably display the same rank order of virulence. This immunodeficient insect model also revealed virulence properties undetected in an immunocompetent murine model of infection. The genetic systems available in both host and pathogen will enable the identification of host-specific components and C. albicans genes involved in the host-fungal interplay.

Animals↗
PubMed1998

Antimicrobial selection, administration and dosage.

Various types of information contribute to the selection of an antimicrobial agent. Initial requirements are diagnosis of the site and nature of the infection, assessment of the severity of the infectious process and medical condition of the diseased animal; these are embodied in clinical experience. Additional considerations include identification of the causative pathogenic microorganism, knowledge of its susceptibility to antimicrobial agents (microbiological considerations) and of the pharmacokinetic properties of the drug of choice and alternative drugs, and their potential toxicity (pharmacological considerations) in the animal species. Select an antimicrobial drug and dosage form appropriate for use in the particular animal species. Usual dosage regimens may be applied, except in the presence of renal or hepatic impairment, when either modified dosage or a drug belonging to another class should be used. The duration of therapy is determined by monitoring the response both by clinical assessment and bacterial culture. A favourable clinical response is the ultimate criterion of successful therapy.

Animal Diseases↗
PubMed2002

7: Soft tissue, bone and joint infections.

Soft tissue infections are common and usually respond rapidly to oral antibiotics; if empirical therapy fails then exposure to unusual organisms should be considered. Septic arthritis requires early recognition, identification of the infecting pathogen and urgent joint washout to prevent irreversible cartilage and bone destruction. Prosthetic joint infection is uncommon but has high morbidity; the best outcomes are achieved with removal of the prosthesis and replacement after at least six weeks of antibiotic therapy. Osteomyelitis often complicates diabetic foot infection with ulceration and is rarely cured by antibiotics alone; early surgical intervention achieves the best outcome.

Adolescent↗
PubMed2002

Serologic evidence of infection with granulocytic ehrlichiae in black bears in Pennsylvania.

Serum samples from 381 black bears (Ursus americanus) killed in Pennsylvania (USA) on 24 November 1997 were analyzed for antibodies reactive to the agent of human granulocytic ehrlichiosis (HGE; Ehrlichia sp.) by indirect immunofluorescence assay. Antibody reactivity to HGE antigen was detected in 21% (81/381) of the samples collected. Reactive samples were reported from 56% (14/25) of the counties where bear samples were collected. Endpoint antibody titer ranged from 1:8 to 1:16, 192, with a geometric mean titer of 1:582. There was no significant difference in antibody prevalence between male and female bears (P < 0.01). However, adult bears were significantly more likely to have reactive antibodies than juvenile bears (P < 0.01). Attempts to amplify and detect granulocytic ehrlichial DNA from corresponding bear blood clots (n = 181) through nested polymerase chain reaction assays were unsuccessful. Further studies are needed for identification of the pathogen-responsible for induction of HGE-reactive. This is the first description of antibodies reactive to the HGE agent in black bears and suggests these mammals are infected with the agent of HGE or an antigenically related ehrlichial species.

Animals↗
PubMedDate not supplied

Changes in gastro-intestinal helminth species diversity in lambs under mixed grazing on irrigated pastures in the tropics (French West Indies).

The development of gastro-intestinal helminth diversity was monitored in lambs grazing alone or grazing with heifers in the ratio one heifer to four lambs. Five successive cohorts of lambs were studied from January 1994 to May 1996. Each cohort of lambs grazed irrigated pastures of Pangola grass for 4 months (from weaning to 6 months of age). A total of 50 lambs was necropsied and their worms counted and identified at the end of each grazing period. Four heifers were also necropsied on one occasion. Special attention was dedicated to the identification of the most pathogenic worm, i.e. Haemonchus spp. Malate dehydrogenase polymorphism in H. contortus was studied in order to evaluate changes between cohorts and between grazing managements. The species diversity was estimated by Shannon diversity indices (main species or all species). It was higher in the mixed grazing group than in the lambs that grazed alone. Diversity increased in successive cohorts. This was due in part to the acquisition of Cooperia spp. of cattle origin. The increase in diversity in the mixed grazing lambs corresponded to the lower faecal egg excretion and better weight gains recorded previously in that group. There seemed to be no cross-transmission of H. similis found in heifers and H. contortus harboured by lambs. The latter species was not morphologically or genetically different in the lambs grazed alone or with heifers, indicating that the presence of cattle did not modify qualitatively the transmission of H. contortus.

Animal Feed↗
PubMed2003

Amyloid precursor protein gene mutations responsible for early-onset autosomal dominant Alzheimer's disease.

According to the "amyloid cascade hypothesis", the accumulation of A beta peptides in the brain is a primary event in the pathogenesis of Alzheimer's disease (AD). Other pathological features (neurofibrillary tangles, neuronal damage and cell death) are regarded as secondary. One of the strong pieces of evidence supporting this hypothesis was the identification of over 20 pathogenic mutations within the APP gene responsible for familial EOAD. The APP mutations are located close to the sites recognised by the alpha-, beta- and gamma-secretases. The mutations affect the APP processing, causing overproduction of A beta42 peptide. The imbalance between A beta production and A beta clearance releases a cascade of subsequent cellular processes leading to AD. In this paper, all APP mutations have been summarised and their molecular effects on the APP metabolism have been discussed.

Age Factors↗
PubMed2004

[Identification of a recurrent mutation in the ROR2 gene in a Chinese family with brachydactyly type B].

OBJECTIVE: To identify the disease-causing mutation in a Chinese family with brachydactyly type B (BDB). METHODS: Genomic DNA was extracted from peripheral blood samples of family members. Exons 8 and 9 of the ROR2 gene were amplified by polymerase chain reaction (PCR) and sequenced directly. Furthermore, the PCR products showing mutation were cloned into pMD18T vector and the insert fragments were sequenced. RESULTS: A 1398-1399 insA heterozygous mutation was detected in the patient. This mutation had been found in German families with BDB. CONCLUSION: To the authors' knowledge, it is the first report on identification of the ROR2 pathogenic mutation in Chinese patients with BDB.

Amino Acid Sequence↗
PubMed2004

[Levofloxacin in patients in the ICU. Factors influencing the choice of dose and its use in combined therapy].

This study aimed to identify factors that influence the selection of different approaches to prescribing levofloxacin (e.g., monotherapy vs. combined therapy, 12-h vs. 24-h interval) and the effect on mortality in the ICU. An observational, prospective, multicenter study was conducted. A logistic regression analysis was performed to identify factors associated with the prescription of levofloxacin in combined therapy and at a dose of 500 mg every 12 hours. In addition, a logistic regression analysis was conducted to determine the impact of the different prescribing methods on mortality in the ICU. The most frequently administered initial dose was 500 mg/24 h (48.5%) and 500 mg/12 h (48.3%). No factors were found to influence the choice of daily dose. A total of 49.7% of levofloxacin prescriptions were in combined therapy. Factors influencing the decision to prescribe a combined regimen included diagnosis of extra-ICU nosocomial infection (OR: 1.97; 95% CI: 1.13-3.42); severe sepsis (OR: 2.56; 95% CI: 1.66-3.94); septic shock (OR: 6.22; 95% CI: 3.54-10.9); and identification of the causative pathogen (OR: 1.99: 95% CI: 1.34-2.95). The mortality rate was 21.4% and the related factors were septic shock (OR: 3.09; 95% CI: 1.38-6.91); treatment failure (OR: 23.4; 95% CI: 12.3-44.6); and combined therapy (OR: 2.36; 95% CI: 1.21-4.59). The selection of the initial dose of levofloxacin was not influenced by any factor, as long as the antibiotic was given in combined therapy in patients in whom the cause of the infection had been identified, in patients with greater systemic response, and in nosocomial infection outside the ICU. The selection of combined therapy was associated with a worse prognosis.

Anti-Infective Agents↗
PubMed2004

[Genetic regulation of pathogenicity and virulence factors in bacteria Erwinia carotovora subsp. atroseptica: identification of kduD gene].

A mutant that cannot utilize pectin substances of plant cell walls was obtained via insertion of mini-mini-Tn5xylE transposon into the chromosome of phytopathogenic bacteria Erwinia carotovora subsp. atroseptica. The inability of mutant cells to utilize these substrates was caused by a failure to accomplish the catabolism of unsaturated digalacturonic acid (UDA). Study of enzymatic activities has established that mutant bacteria lost the ability to produce 2,5-diketo-3-deoxygluconate dehydrogenase, an enzyme of intracellular UDA utilization. Molecular cloning of the mutant gene was conducted, and its nucleotide sequence was determined. It was shown that the nucleotide sequence of this gene had an 82% homology with the sequence of Erwinia chrysanthemi EC3937 kduD gene encoding 2,5-diketo-3-deoxygluconate dehydrogenase. The intergene kdul-kduD region in bacteria Erwinia carotovora subsp. atroseptica is shorter in length by 98 nucleotides than the corresponding region of Erwinia chrysanthemi and does not contain promoter sequences. The kduD gene was located at 126.8 min of the Erwinia carotovora subsp. atroseptica genetic map.

Base Sequence↗
PubMed2001

[Usefulness of the molecular techniques for detecting and/or identifing of parasites and fungi in humans and animals or pathogens transmitted by ticks (Part I)].

After a long period of using basic microscopic, immunological and biochemical methods for diagnosis, rapid development of nucleic acids investigation enabled introduction of specific and sensitive methods of detection of pathogenic agents on the molecular level. Among others, polymerase chain reaction (PCR), discovered in mid of 80'ies and then automatized, offered an attractive alternative to conventional testing systems. In this paper we describe reliable diagnostic tests widely used in the world, including Poland, and capable of detecting different disease agents as parasites and fungi in clinical specimens and pathogens of emerging zoonotic diseases in ticks. The possibilities of using molecular methods for determination of Plasmodium falciparum drug resistance is also discussed. Moreover, the report offers information concerning kinds of molecular tests and institutions in which there are executed.

Animals↗
PubMed2005

Contemporary methods for detection of microbial infections in transplanted tissues.

Infective processes developing after transplantation are diagnosed mainly in the specimens harvested from blood and exudates. Not much attention has been focused on identification of microorganisms present in the graft or penetrating the graft from the recipient. Although a progress has been made with respect to detection of viruses there is still little knowledge on the pathological role of bacteria, transplanted together with the graft or acquired from the recipient, in evoking or enhancing the rejection reaction (heterologous immune response). Recently developing molecular techniques allow us to detect bacterial genetic materials in clinical specimens. This article reviews commonly used methods for detection, identification and typing bacterial pathogens. It focuses on specific and universal methods based on gene sequencing, PCR and techniques based on polymorphic DNA. We also present the examples of genes and microorganisms analysed in laboratories. Together with conventional microbiological methods the molecular tests can serve as a key for better understanding the bacterial presence in tissues, not necessarily causing inflammation, quite often being commensal, but also evoking host reaction under certain so far not defined circumstances.

Bacterial Infections↗
PubMed2006

[Identification of Mycobacteriaceae species based on the hsp-65 gene polymorphism analysis by PCR - RFLP].

The polymorphism of the short fragment of the heat shock protein 65 encoding gene was evaluated by the PCR - RFLP technique described by Telenti and further developed by Devallois for identification of mycobacterial species in routine laboratory work. We analysed 58 strains representing 25 different mycobacterial species (24 reference strains and 34 clinical isolates). The results obtained by PCR-RFLP and HPLC identification techniques were highly concordant The results were compatible for 87,5% (21 / 24) reference strains and for 97,1% (33/34) clinical isolates. The PCR - RFLP method allowed for accurate identification mycobacterial species, especially pathogenic strains. Restriction patterns obtained for 25 species of Mycobacteriaceae genus could help in constructing the data base and algorithms used in routine laboratory practice.

Algorithms↗
PubMed1990

[Group B streptococci in neonatal pathology: pathogenetic mechanism, diagnosis and prevention].

Group B streptococci have recently attracted the attention of researchers as the causative agents of human neonatal disease. They are currently encountered much more frequently than it was believed previously. Various types of adult pathogen carriers have been described; this accounts for the numerous sources and pathways of infection transmission, both vertical and horizontal. The transmission risk depends on many factors, vaginal colonization in the parturient being of special import. The level of the pathogen adhesion to the barrier epithelium is reflective of the tissue sensitivity to infection. Increased sensitivity of the vaginal epithelium to B streptococci adhesion in association with the intake of some contraceptives has been found. The adhesive activity of avirulent streptococci B strains is shown to be higher than in the virulent strains, which is especially important in mixed virus bacterial infections. The streptococcal infection of high mortality is underlain by activation of persisting avirulent streptococci B that manifest their pathogenicity as a result of the virus-specific modifications in the host cell membrane. During 1985-1987, in Leningrad Institute of Gynecology and Obstetrics over 80 strains of streptococci B were isolated, the leading serotypes being Ia/C, Ib/C, II/C, III/R. Only 54% of the studied pregnancies attended with the streptococcus carriage had a favourable neonatal outcome. The strain serotypes from maternal isolates and abortuses fully correlated. Further improvement of the laboratory diagnosis and means of the pathogen and its carriers identification is a current priority.

Bacterial Adhesion↗