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At least 1,135 records · Page 63Linked to original sources
PubMed1990

Identification of Actinobacillus actinomycetemcomitans by gold immunolabeling and scanning electron microscopy.

Recent evidence suggests that dental plaque is not a homogeneous bacterial mass but, on the contrary, specific bacterial morphotypes and species may be preferentially located within certain microenvironments. The aim of the present study was to develop combined gold immunolabeling and scanning electron microscopic (SEM) techniques for the identification of periodontal pathogens in subgingival dental plaque and on the root surfaces of extracted teeth. Suspensions of pure A. actinomycetemcomitans cultures or suspensions of A. actinomycetemcomitans mixed together with other oral bacteria were prepared, labeled with goat anti-rabbit IgG conjugated with 5 nm or 40 nm colloidal gold particles, and observed by SEM using both secondary and back-scattered imaging. Scanning electron microscopy demonstrated that the A. actinomycetemcomitans bacterial cell surface was specifically labelled. There was no cross-reaction with any of the other bacterial morphotypes. Only the labeled A. actinomycetemcomitans were visible in mixtures examined by back-scattered imaging scanning electron microscopy. The combined techniques of gold immunolabeling and SEM may, therefore, be useful in identifying A. actinomycetemcomitans in subgingival plaque samples and on the root surfaces of extracted teeth as well as in studies of bacterial ecology in dental plaque, in general.

Actinobacillus↗
PubMed2006

Enrichment of open reading frames presented on bacteriophage M13 using hyperphage.

The enrichment of open reading frames (ORFs) from large gene libraries and the presentation of the corresponding polypeptides on filamentous phage M13 (phage display) is frequently used to identify binding partners of unknown ORFs. In particular phage display is a valuable tool for the identification of pathogen-related antigens and a first step for the development of new diagnostics and therapeutics. Here, we introduce a significant improvement of phage-based ORF enrichment by using Hyperphage, a helperphage with a truncated gIII. The methods allow both the enrichment of ORFs from cDNA libraries and the display of the corresponding polypeptides on phage, thus combining ORF enrichment with a screening for binding in one step without any further subcloning steps. We demonstrated the benefits of the method by isolating the sequences encoding two predicted immunogenic epitopes of the outer membrane protein D encoding gene (ompD) of Salmonella typhimurium. Here, we showed that when using a mixture of three constructs with only one containing an ORF solely this correct construct could be reisolated in phage particles. Further; both epitopes were detected by enzyme-linked immunosorbent assay (ELISA), demonstrating correct translation of fusion proteins. Furthermore, the enrichment system was evaluated by the enrichment of ORFs from total cDNA of lymphocytes. Here, we could show that 60% of the phage contained ORFs, which is an increase of an order of magnitude compared with conventional phage expression system. Together these data show that the Hyperphage-based enrichment system significantly improves the enrichment of ORFs and directly allows the display of the corresponding polypeptide on bacteriophage M13.

Amino Acid Sequence↗
PubMed2003

Ethidium monoazide for DNA-based differentiation of viable and dead bacteria by 5'-nuclease PCR.

PCR techniques have significantly improved the detection and identification of bacterial pathogens. Even so, the lack of differentiation between DNA from viable and dead cells is one of the major challenges for diagnostic DNA-based methods. Certain nucleic acid-binding dyes can selectively enter dead bacteria and subsequently be covalently linked to DNA. Ethidium monoazide (EMA) is a DNA intercalating dye that enters bacteria with damaged membranes. This dye can be covalently linked to DNA by photoactivation. Our goal was to utilize the irreversible binding of photoactivated EMA to DNA to inhibit the PCR of DNA from dead bacteria. Quantitative 5'-nuclease PCR assays were used to measure the effect of EMA. The conclusion from the experiments was that EMA covalently bound to DNA inhibited the 5'-nuclease PCR. The maximum inhibition of PCR on pure DNA cross-linked with EMA gave a signal reduction of approximately -4.5 log units relative to untreated DNA. The viable/dead differentiation with the EMA method was evaluated through comparison with BacLight staining (microscopic examination) and plate counts. The EMA and BacLight methods gave corresponding results for all bacteria and conditions tested. Furthermore, we obtained a high correlation between plate counts and the EMA results for bacteria killed with ethanol, benzalkonium chloride (disinfectant), or exposure to 70 degrees C. However, for bacteria exposed to 100 degrees C, the number of viable cells recovered by plating was lower than the detection limit with the EMA method. In conclusion, the EMA method is promising for DNA-based differentiation between viable and dead bacteria.

Bacteria↗
PubMed1995

Epidemiology, therapy and costs of nosocomial infection.

In the current climate of cost containment and quality control, nosocomial infection is a worrisome adverse event in hospital care. Hospitalised patients require care for increasingly severe illnesses, and are therefore more susceptible to infection, especially by opportunistic micro-organisms. It is thus necessary to accurately assess and adjust for the severity of the underlying illness in studies of risk factors involved in nosocomial infections. The appearance of new diagnostic and therapeutic techniques provides novel opportunities for infection control and represents a constant challenge to hospital systems. The continuous selection of resistant flora, together with the identification of new pathogens, calls for a reconsideration of hospital policies regarding the dispensation of antibiotics. Epidemiological surveillance continues to be the most important aspect of attempts to monitor infection control programmes, and to identify changes in risk factors that may increase the infection rate. Among the major challenges now facing the infection control practitioner is the use of nosocomial infection rates as an indicator of quality of care. Awareness of infection statistics would serve as a stimulus to the prevention and control of infection, but would be useless if not accompanied by adequate systems to guarantee the comparability of data from different studies and centres. Suitably sensitive and specific surveillance systems should be developed, and the use of site-specific and procedure-specific infection rates adjusted for the patient's intrinsic risk should be encouraged.

Anti-Bacterial Agents↗
PubMed2004

A woman with infectious endocarditis caused by Abiotrophia defectiva.

A 74-year-old woman with recurrent fever and multiple joint pain was admitted to Hokkaido University Hospital. Trans-esophageal echocardiogram revealed bacterial vegetation and destruction of the aortic valve. Although few bacteria grew in regular blood agar, Gram-positive coccobacillus was specifically grown in chocolate blood agar and Brucella agar, and it was identified to be Abiotrophia defectiva. Infectious endocarditis caused by Abiotrophia defectiva was diagnosed, she was treated with diuretics, penicillin G and gentamicin, and she immediately improved. Infectious diseases caused by Abiotrophia defectiva are extremely rare, and identification of this pathogen is important, as its bacterial characteristics require proper attention.

Aged↗
PubMed1998

The evolving contribution of renal pathology to understanding interstitial nephritis.

One hundred years of progress in the study of interstitial nephritis has expanded our diagnostic entities, resulted in identification of numerous pathogenic events, and defined the nature of the inflammatory infiltrate in ways that are useful both for general understanding and for diagnostic classification. We stand poised to enter the next hundred years with new techniques applicable to renal biopsies that detect specific biologic activities in situ in tissue sections. In the future, the information gained from these techniques is likely to result in refined and more accurate assessments of prognosis in patients with kidney disease, and to guide therapeutic interventions designed to interrupt specific sequences of active renal injury.

Biopsy↗
PubMed1996

Infectious myositis. A tropical disease steals out of its zone.

Infectious myositis is an acute infection of skeletal muscle that is increasing in prevalence with the increased incidence of HIV disease. Typical presentation is asymmetric swelling of an isolated muscle, with exquisite pain and fever. Results of laboratory studies are usually nonspecific, but magnetic resonance imaging of the affected area suggests the diagnosis. Muscle biopsy and direct identification of the pathogen on tissue culture are required, because the list of potential pathogens is long. With prompt treatment, most patients achieve complete resolution and return to their preinfection level of health.

Adult↗
PubMed2006

ESBL - from petri dish to the patient.

Treatment of extended spectrum beta-lactamase (ESBL) producing strains of Enterobacteriaceae has emerged as a major challenge in hospitalised as well as community based patients. Infections due to ESBL producers range from uncomplicated urinary tract infection to life threatening sepsis. Although several reviews have been published in the literature about the detection and identification of these pathogens in the laboratory, there is not much guidance in Indian literature about how these organisms should be treated in clinical settings. The present article tries to address the clinical questions in the management of ESBL producing organisms. The article emphasises on antibiotic choice, pharmaco-therapeutic considerations, non-antibiotic aspects of management, and testing of clinical samples in the initial screening of patients for resistant gram negative organisms.

Anti-Bacterial Agents↗
PubMed2006

The 23S rRNA gene PCR-RFLP used for characterization of porcine intestinal spirochete isolates.

Using three reference strains of Brachyspira hyodysenteriae (B204, B234, B169), one B. pilosicoli (P43/6/78), one B. murdochii (56-150), one B. intermedia (PWS/A), one B. innocens (B256) and ten Korean isolates, PCR-RFLP analysis of DNA encoding 23S rRNA was performed to establish a rapid and accurate method for characterizing porcine intestinal spirochetes. Consequently, B. hyodysenteriae and B. pilosicoli revealed different restriction patterns; however, the other three species shared the same pattern. These findings are not consistent with a prior report. Differences in 23S rRNA gene sequences, between two B. murdochii strains, 56-150 and 155-20, were observed. These results indicate that 23S rRNA PCR-RFLP could be used as an identification method for pathogenic Brachyspira spp. (B. hyodysenteriae and B. pilosicoli) as well as an epidemiological tool for characterizing spirochetes isolated from swine.

Animals↗
PubMed1997

Fingerprinting of Ehrlichia species by repetitive element polymerase chain reaction.

To facilitate identification of ehrlichial pathogens, we developed a new technique based on fingerprints resulting from repetitive element polymerase chain reaction (rep-PCR). This technique uses consensus tRNA primers to generate amplification products that reflect distance polymorphisms between adjacent tRNA genes. Species-specific fingerprint patterns were obtained for seven Ehrlichia spp., as well as the unnamed causative agent of human granulocytotropic ehrlichiosis. Bands ranged in size from approximately 50 to 1,000 base pairs. Banding patterns varied depending on dilution of template DNA, with lower dilutions giving more complex banding patterns. These preliminary data indicate that repetitive-sequence-based PCR appears to be a useful technique for identifying ehrlichial organisms to the species, and perhaps the strain level. Compared with other conventional molecular-biologic methods, rep-PCR offers the advantages of ease of performance and rapid availability of results.

Bacterial Typing Techniques↗
PubMed1989

Rheumatologic manifestations of infection with human immunodeficiency virus (HIV).

PURPOSE: To review the various rheumatologic manifestations of human immunodeficiency virus (HIV) infection and to discuss their potential pathogenic mechanisms. DATA IDENTIFICATION: A literature search using MEDLINE (1981 to 88) and Index Medicus (1981 to 88) and review of references from all identified articles. STUDY SELECTION: All studies and case reports addressing arthritis, myopathies, vasculitis, the sicca syndrome, systemic lupus erythematosus, and autoimmune phenomena in HIV-infected patients are cited. RESULTS OF DATA SYNTHESIS: The Reiter syndrome and other reactive arthritides are the commonest arthritides seen in HIV-infected patients. Psoriatic arthritis and septic arthritis with opportunistic agents, as well as an articular pain that is severe, acute, and intermittent, may also occur with HIV infection. An arthritis that may be specific for the acquired immunodeficiency syndrome (AIDS) has been described. Myopathies, especially of a polymyositic type, vasculitis, and the sicca syndrome are also part of the spectrum of rheumatologic presentation of HIV infection. Several autoimmune phenomena, such as antinuclear and anticardiolipin antibodies, as well as lupus anticoagulant, have been reported in HIV-infected patients. CONCLUSIONS: The Reiter syndrome, reactive arthritis, polymyositis, and the sicca syndrome may herald the onset of clinically evident HIV infection. These diseases and others may also occur in patients with full-blown AIDS. Furthermore, HIV infection may mimic systemic lupus erythematosus.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[Sorsby's fundus dystrophy: a literature review].

BACKGROUND: Sorsby's fundus dystrophy (SFD) is an autosomal dominant macular dystrophy first described in a 1949 study of five British families, and it has received attention because of its clinical similarity to age-related macular degeneration and recent identification of the pathogenic gene. CLINICAL FEATURES: To date, about twenty families with SFD have been reported from Europe, North America, South Africa, Australia, and Japan. A review of the literature found that the age of onset is usually during the fourth or fifth decade of life, the prominent ophthalmoscopic finding is hemorrhagic or atrophic lesion in the macula, and functional prognosis is usually unfavorable due to additional peripheral chorioretinal dystrophy, ultimately leading to poor ambulatory vision in the late decades of life. MOLECULAR GENETICS: Recent molecular studies have identified mutations in the tissue inhibitor of metalloproteinases-3 (TIMP 3) gene as the pathogenic gene defect. CONCLUSIONS: TIMP 3 gene examinations not only allow accurate diagnosis but also lay the groundwork for future studies of potential therapeutic protocols.

Corneal Dystrophies, Hereditary↗
PubMed2000

[Maternal genital infections and premature delivery].

The etiology of preterm birth remains elusive being probably multifactorial. Fifty years ago, genital infection was proposed as an important risk factor. Recent advances in the identification of several pathogens together with the potential rôle of bacterial vaginosis have generated renewed interest. However may studies suffered from methodological flaws and definitive answers are yet to come. In addition, studies looking at genital infections on pathological cervices already effaced or dilated, suggested that infection may play an additive interactive role to preterm birth.

Female↗
PubMedDate not supplied

[Use of polymerase chain reaction for pediatric diagnosis].

Basic principles of main molecular biology techniques: polymerase chain reaction (PCR) and its variants; asymmetric PCR, ARMS, nested PCR, multiplex PCR and competitive PCR are discussed. Nucleic acids techniques are making increasing progress in molecular diagnostics. Sequence analysis of amplified DNA allows better identification of the pathogen, detection of mutant genes and more accurate prognosis and therapy of certain diseases.

Child↗
PubMed2000

[Surgery of hereditary colorectal carcinoma].

Hereditary colorectal cancer syndromes account for about 7% of all colorectal carcinomas. The most frequent form is Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Identification, cloning and sequence analysis of the predisposing genes enables identification of mutation carriers and non-mutation carriers, respectively. These genetic informations can be used in an individually tailored clinical surveillance program and may ultimately result in standard preventive surgical treatment. In classical FAP the surgical standard is performing a restorative proctocolectomy. It is still unclear now, if this procedure should be modified in attenuated forms (colectomy with ileorectostomy). Due to a high rate of synchronous and metachronous carcinomas a subtotal colectomy in the case of first colon cancer seems to be indicated in HNPCC patients. A proctocolectomy or a restorative proctocolectomy should be weighed in case of carcinomas in the lower rectum. These procedures should be performed under the precondition of identification of the pathogenic germline mutation in the patient, only. In addition, a synchronous prophylactic hysterectomy with oophorectomy should be recommended postmenopausal gene carriers. Intensive counseling of the patient should proceed these preventive procedures involving surgeons, gastroenterologists, geneticists, molecular biologists, gynecologists, physicians and psychologists. It is recommended to have patients treated exclusively in specialized centers. Currently, six interdisciplinary centers for cancer surveillance and early diagnosis in hereditary colorectal cancer are being sponsored in Germany by the Deutsche Krebshilfe since 1999. In the future clinical studies have to be conducted to evaluate the efficacy of extended colorectal resections versus efficacy of surveillance and conventional resections according to general oncological principles.

Adenomatous Polyposis Coli↗
PubMed2002

[Blood culture update].

BACKGROUND: Blood culture is one of the most important bacteriological examinations with important clinical and therapeutic consequences. Blood cultures should be ordered in all patients with signs suggesting septicemia, endocarditis or severe infection (pneumococcal pneumonia, bacterial meningitis with bloodstream dissemination). Blood culture methods have evolved considerably over the last twenty years. After using manual methods for many years, read by non-standardized visual methods, the development of media with defined compositions and supplemented to allow growth of bacteria difficult to culture has been associated with the development of automatic blood culture devices. AUTOMATIC DEVICES: These devices have undergone rapid improvement. Semi-automatic devices (Bactec NR-660) were rapidly followed by completely automatic techniques, including four devices currently available: since 1989 Bio-Argos (Rio-Rad) and Bact/Alert (Organon-Teknika) and in 1993, Bactec 9240 (Becton-Dickinson) and Vital (BioMérieux). All these devices allow automatic detection of CO2 produced during bacterial growth. Automatic reading systems provide continuous output avoiding the need for invasive methods and thus the risk of contamination in addition to saving time. Potential application to achieve quantitative blood cultures for intensive care units is in the development stage. CONSEQUENCES: The reliability of these devices is well recognized and their contribution to severe bacterial infection is undeniable. There are certain limitations however related to material cost and the non-identification of the pathogen involved. Molecular biology techniques open new perspectives in this field. The evolution of techniques, definitions, and pathogenic approach to septicemia must be revisited as new infectious situations have been identified at the same time as new investigation tools resulting from considerable technological progress. New methods of blood culture have largely contributed to this progress.

Bacteriological Techniques↗
PubMed2002

[Diagnosis and therapy of infectious endocarditis. What measures are required?].

Infectious endocarditis remains a potentially life-threatening disease, the outcome of which can be substantially influenced by rapid diagnosis and initiation of suitable treatment. Leading clinical features are fever, a new sound suggestive of valvular insufficiency and, when the course is subacute, anemia. The main diagnostic procedures are transthoracic and transesophageal echocardiography that reliably identify vegetation, valvular insufficiency and abscess. Of decisive importance for treatment and prognosis is the rapid identification of the pathogen by means of blood culture and, if necessary, serologic and molecular-biologic measures. Antimicrobial treatment is applied in accordance with the recommendations of the American Heart Association. Surgical treatment is indicated in the event of refractory infection, severe valvular insufficiency with heart failure, valve avulsion, recurrent emboli or large floating vegetation with an elevated risk of embolism.

Anti-Bacterial Agents↗
PubMed2002

Decreasing trend in the occurrence of Salmonella enterica serotype Typhi amongst hospitalised children in Kolkata, India during 1990-2000.

In a prospective hospital based surveillance, 1454 children clinically diagnosed as typhoid fever were enrolled during the period between 1990 to 2000. Of them 336 (23.1%) children were positive for Salmonella enterica serotype Typhi by blood culture. A declining trend of hospitalization and identification of the pathogen was observed from 1992 to 2000 as compared to 1990-1991. A declining trend of resistance to the commonly used anti-typhoid drugs was seen in the S. enterica serotype Typhi isolates. Recently in 2000, nine strains were detected as ciprofloxacin resistant. Misuse and overuse of ciprofloxacin for the treatment of typhoid fever influenced the development of ciprofloxacin resistant strains of S. enterica serotype Typhi in and around Kolkata.

Child↗