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PubMed1989

Diagnostic studies of nosocomial diarrhea in children: assessing their use and value.

During a 17-month period (01/11/85-05/31/86) 225 cases of nosocomial diarrhea were identified in a children's hospital. Diarrhea was considered to be nosocomial if it began at least 72 hours after the patient's hospital admission or within 3 days after discharge. One or more routine diagnostic studies for identification of a pathogen were performed in 195 (87%) cases. The most commonly performed test was the bacterial stool culture. None of these samples yielded a bacterial pathogen. The only pathogens detected by routine laboratory studies were rotavirus (61/137 [45%] samples were positive for rotavirus by ELISA) and Clostridium difficile (9/54 [17%] positive for toxin). Of the patients whose tests were positive for rotavirus 56 were younger than 2 years of age, and all were identified in the winter and spring. When multiple stool samples were tested by the diagnostic laboratory, rotavirus was identified in an additional 14 patients whose initial stool samples were negative for rotavirus. All patients whose tests were positive for C. difficile toxin had received antibiotics within the previous 3 months. Ova/parasites were not detected in 53 of the tested stools. We also identified enteric adenovirus in six patients. Viruses were identified in 95 (42%) of the 225 cases of nosocomial gastroenteritis. Nosocomial diarrhea is common in a children's hospital. Rotavirus is the most commonly identified pathogen. Rotavirus testing is valuable in children with nosocomial diarrhea who are younger than 2 years of age, especially in the winter and spring. Multiple samples may be necessary to identify rotavirus. C. difficile toxin assay should be considered for patients who are receiving or who have received antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross Infection↗

PubMed1995

The challenge of vancomycin-resistant enterococci: a clinical and epidemiologic study.

BACKGROUND: Vancomycin-resistant enterococci have been recovered with increasing frequency from hospitalized patients. Risk factors, mode of nosocomial transmission, extent of colonization in hospitalized patients, and treatment options for these organisms have not been completely delineated. METHODS: We studied 53 patients (group A) with vancomycin-resistant enterococci isolated from various clinical specimens and also surveyed for vancomycin-resistant enterococci in stool specimens submitted for Clostridium difficile toxin assays (group B). Stool specimens submitted for identification of bacterial pathogens and stool specimens from hospital employees were also analyzed for vancomycin-resistant enterococci. RESULTS: Seventy-six isolates of vancomycin-resistant enterococci were recovered in group A. Five of these patients harbored vancomycin-resistant enterococci on admission. Fifty-three of 289 group B stool specimens submitted for C. difficile toxin assays yielded vancomycin-resistant enterococci. Cephalosporins and vancomycin were the most common antimicrobial agents received by both groups of patients. Enterococcus faecium isolates were more resistant than Enterococcus faecalis isolates to antimicrobial agents. All isolates exhibited high-level aminoglycoside resistance and were not beta-lactamase producers. There were at least 15 different molecular clones of E. faecium and three of E. faecalis. Vancomycin-resistant enterococcal bacteremia was associated with a 100% in-hospital mortality rate. CONCLUSIONS: Multidrug-resistant and vancomycin-resistant enterococci have become important nosocomial pathogens that are difficult to treat. Vancomycin-resistant enterococcal bacteremia was associated with a poor prognosis. We found a high rate of colonization in patients with suspected C. difficile toxin colitis. Judicious use of vancomycin and broad-spectrum antibiotics is recommended, and strict infection control measures must be implemented to prevent nosocomial transmission of these organisms.

Adult↗

PubMed1995

Immunization with a soluble recombinant HIV protein entrapped in biodegradable microparticles induces HIV-specific CD8+ cytotoxic T lymphocytes and CD4+ Th1 cells.

One of the major obstacles to the development of successful recombinant vaccines against human immunodeficiency virus (HIV) and other intracellular pathogens is the identification of a safe and effective vaccine delivery system for the induction of cell mediated immunity with soluble protein antigens. In this study it was demonstrated that immunization with a recombinant HIV envelop (env) protein entrapped in biodegradable poly(lactide-co-glycolide) (PLG) microparticles induced consistent HIV-specific CD4+ and CD8+ T-cell responses in mice. Major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes (CTL) responses were detected following a single systemic immunization with gp120 entrapped microparticles and when given by the intranasal (i.n.) route induced HIV-specific CD8+ CTL and secretory IgA. Furthermore immunization with gp120 entrapped in microparticles generated CD4+ T cells that secreted moderate to high levels of IFN-gamma. Therefore, PLG microparticles are a safe and effective means of delivering antigen to the appropriate processing site for the generation of class I-restricted CTL, and are also capable of inducing Th1 cells.

Animals↗

PubMed2004

Activation of programmed cell death markers in ventral horn motor neurons during early presymptomatic stages of amyotrophic lateral sclerosis in a transgenic mouse model.

The identification of the pathogenic mechanism of selective motor neuron (MN) death in amyotrophic lateral sclerosis (ALS) may lead to the development of new therapies to halt or slow the disease course. A novel, MN-specific, Fas-mediated programmed cell death (PCD) pathway has been reported in MNs which involves the activation of p38 MAP kinase (phospho-p38) and neuronal nitric oxide synthase (nNOS). PCD was found to be exacerbated in MNs expressing ALS-linked superoxide dismutase (SOD) mutations. Because this MN-specific pathway was investigated in vitro, we performed an in vivo study to evaluate its potential involvement in MN loss in the lumbar region of spinal cord of mutant SOD transgenic (G93A) mice. Compared to nontransgenic littermates, we found significant increases in the numbers of immunopositive ventral horn MNs of G93A mice as young as 60 days of age for several constituents of this putative PCD pathway, including phospho-p38, nNOS, phospho-ASK1 MAP kinase kinase, and active caspase-3. This study provides in vivo evidence of an MN-specific PCD pathway that may be a pathogenic mechanism of ALS and may be activated very early in the disease process, well before clinical symptoms are evident (200 days). These findings suggest that early diagnosis and therapeutic intervention may be critical for the successful treatment of the disease. These enzymes may provide new markers for earlier diagnosis of ALS and new molecular targets for therapeutic intervention.

Age Factors↗

PubMed2005

Isolation of the Taenia crassiceps antigens from a phage display cDNA library and evaluation of their use for diagnosis of neurocysticercosis.

A novel cDNA cloning strategy consisting in elimination of non-coding DNA sequences from 3' regions of cDNAs was applied to construct the Taenia crassiceps phage displayed cDNA expression library. After biopanning using immune sera, three phage clones expressing T. crassiceps-derived antigens specifically recognizing antibodies present in cerebrospinal fluid and plasma samples from neuroimaging-confirmed neurocysticercosis patients were selected. This novel cloning strategy may be applied to other pathogens allowing rapid identification of peptides/proteins for immunodiagnostic tests.

Amino Acid Sequence↗

PubMed2005

Latex agglutination for bacterial antigens and meningococcus PCR: two useful tools in legal sudden deaths.

Bacterial infections are considered to be a major cause of sudden deaths. The recognition of infections caused by Neisseria meningitidis is an essential duty of medicolegal offices due to the risk of secondary cases. Since other microorganisms, such as Haemophilus influenzae and Streptococcus pneumoniae, are also involved in infectious sudden deaths, the identification of the pathogen responsible for death is essential in order to establish a positive diagnosis while also preventing secondary meningococcal cases. However, because of the unreliability of culture methods used for autopsy specimens and the fragile nature of the microorganisms, other techniques were used. In this study, the detection of specific antigens of N. meningitidis (serogroups A, B, C, Y and W135), H. influenzae type b, S. pneumoniae and Group B Streptococcus was undertaken in 40 samples from sudden death cases in legal procedures with a latex agglutination test. In addition, a meningococcus polymerase chain reaction (PCR) assay (ctrA, crgA and siaD genes) was also used as a corroboration method for positive N. meningitidis agglutinations. Eleven cases of sudden death were confirmed to be due to meningococcus while one case was confirmed to have been caused by H. influenzae type b fulminant epiglottitis. Rapid laboratory diagnosis of meningococcal infection allowed contacts management and notification to the health authorities. From the point of view of the authors, forensic diagnosis of unascertained deaths should include latex agglutination and meningococcus PCR when a fulminant infection by N. meningitidis or H. influenzae is suspected as well as in deaths where the cause is unclear.

Adolescent↗

PubMed2025

Costs and cost-effectiveness of returning secondary findings from genomic sequencing based on the return of additional findings in the 100,000 Genomes Project.

PURPOSE: To assess costs and cost-effectiveness of returning additional findings from genome sequencing using data from the 100,000 Genomes Project (100kGP). METHODS: A model-based cost-utility analysis combining yield, consent rates, and cost data from the 100kGP with published estimates of downstream costs and quality-adjusted life years expected to accrue over a lifetime, after the identification of a pathogenic variant. RESULTS: The cost of returning additional findings to participants in the 100kGP was £7.1m or £81 per participant, with a yield of 0.85% for consented participants. The estimated lifetime incremental cost per participant was £125 and quality-adjusted life years 0.004, giving an incremental cost-effectiveness ratio of £28,830. Implementing a policy of returning additional findings is unlikely to be cost-effective (ie, 13%) at a willingness-to-pay threshold of £20,000. A short-term cost of returning findings of £43 per participant or lower (compared with the base case of £81) would result in an incremental cost-effectiveness ratio of less than £20,000. Alternatively, cost-effectiveness may be improved by returning additional findings to younger patient populations. CONCLUSION: Return of additional findings following genome sequencing for this group of conditions may not be a cost-effective use of health care system resources. Our cost-effectiveness outcomes rely on published estimates and should be validated through long-term follow-up data.

Humans↗

PubMed2006

Information systems in food safety management.

Information systems are concerned with data capture, storage, analysis and retrieval. In the context of food safety management they are vital to assist decision making in a short time frame, potentially allowing decisions to be made and practices to be actioned in real time. Databases with information on microorganisms pertinent to the identification of foodborne pathogens, response of microbial populations to the environment and characteristics of foods and processing conditions are the cornerstone of food safety management systems. Such databases find application in: Identifying pathogens in food at the genus or species level using applied systematics in automated ways. Identifying pathogens below the species level by molecular subtyping, an approach successfully applied in epidemiological investigations of foodborne disease and the basis for national surveillance programs. Predictive modelling software, such as the Pathogen Modeling Program and Growth Predictor (that took over the main functions of Food Micromodel) the raw data of which were combined as the genesis of an international web based searchable database (ComBase). Expert systems combining databases on microbial characteristics, food composition and processing information with the resulting "pattern match" indicating problems that may arise from changes in product formulation or processing conditions. Computer software packages to aid the practical application of HACCP and risk assessment and decision trees to bring logical sequences to establishing and modifying food safety management practices. In addition there are many other uses of information systems that benefit food safety more globally, including: Rapid dissemination of information on foodborne disease outbreaks via websites or list servers carrying commentary from many sources, including the press and interest groups, on the reasons for and consequences of foodborne disease incidents. Active surveillance networks allowing rapid dissemination of molecular subtyping information between public health agencies to detect foodborne outbreaks and limit the spread of human disease. Traceability of individual animals or crops from (or before) conception or germination to the consumer as an integral part of food supply chain management. Provision of high quality, online educational packages to food industry personnel otherwise precluded from access to such courses.

Consumer Product Safety↗

PubMed2026

National Antimicrobial Resistance Monitoring System: Three Decades of Advancing Public Health Through Integrated Surveillance of Antimicrobial Resistance.

Antimicrobial resistance (AMR) occurs when bacteria and other microorganisms adapt in ways that make medicines less effective, causing infections that are harder to treat and more likely to spread. According to the Centers for Disease Control and Prevention (CDC), AMR infections affect millions of Americans each year and contribute to thousands of deaths (CDC, 2019). After three decades of operation, the U.S. National Antimicrobial Resistance Monitoring System (NARMS) stands as a model of sustained, collaborative public health surveillance. What began in 1996 as an effort to track resistance in Salmonella and E. coli O157 has evolved into a One Health surveillance network monitoring AMR across the farm-to-fork continuum. Through a partnership among CDC, the Food and Drug Administration (FDA), the U.S. Department of Agriculture (USDA), state and local health departments, and universities, NARMS has become the backbone of foodborne AMR surveillance in the United States. The past decade has been particularly transformative. NARMS explored new sampling to include companion animals, minor livestock, aquaculture, surface water, and wildlife. Whole-genome sequencing (WGS) revolutionized the program's capabilities, enabling timely identification of emerging pathogens and revealing how resistance genes spread. Near real-time public dashboards make NARMS data accessible to researchers, clinicians, regulators, and policymakers. NARMS data shape decisions about new animal drug approvals, guide stewardship programs, and inform clinical treatment guidelines nationwide. As NARMS enters its fourth decade with a 2026-2030 strategic plan, the program will leverage artificial intelligence and metagenomics while expanding surveillance to fill remaining gaps ensuring this vital system continues to protect the food supply and both human and animal health from AMR.

Antimicrobial Resistance (AMR)↗

PubMed2005

Diagnosis of parapneumonic pleural effusion by polymerase chain reaction in children.

PURPOSE: Most pleural effusions are associated with bacterial pneumonia, and the identification of the pathogen will assist the therapeutic decision. A specific method that is not affected by previous antibiotic therapy is sought to detect the main causative agents of pneumonia in infants and children (Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus). The aim of the present study was to compare the polymerase chain reaction (PCR) technique with standard culture methods in identifying bacterial infections in infants' and children's pleural effusion. METHODS: Samples obtained from pediatric patients (n = 37) with a diagnosis of pneumonia associated to pleural effusion, submitted to thoracentesis, were analyzed by PCR with specific primers. RESULTS: The PCR technique identified the presence of bacterial infection in a larger proportion (95.2%) than the standard culture method (33.3%) on complicated pleural effusion samples. The microorganism detection on uncomplicated pleural effusion samples was positive only by the PCR method (31.3%). The frequencies of microorganisms identified on complicated pleural effusion were 57.1% of all patients for methicillin-resistant Staphylococcus; 52.4%, S pneumoniae; 28.6%, S aureus; and 23.8%, H influenzae. The previous use of antibiotics interferes with standard culture method, but it did not interfere with the PCR results. CONCLUSIONS: The molecular diagnosis by PCR method could improve the etiologic diagnosis and might help to guide the treatment of parapneumonic effusion in children.

Child↗

PubMed2005

Rapid, differential diagnosis of orthopox- and herpesviruses based upon real-time PCR product melting temperature and restriction enzyme analysis of amplicons.

Orthopoxviruses tend to have non-specific early symptoms that cannot be differentiated readily from other infectious exanthemas, such as varicella-zoster virus (VZV) or disseminated herpes simplex virus (HSV) infections. A rapid assay was developed for the differential diagnosis of orthopoxviruses and herpesviruses based upon the melting temperatures of real-time PCR amplicons. A mean melting temperature difference of 8.7 degrees C was observed between the products amplified from the two virus families. Further identification of individual pathogens was made using restriction enzyme analysis. The assay was able to identify correctly viruses from quality control panels of herpes and orthopoxviruses.

DNA Primers↗

PubMed2006

Cell mediated immunity to meet the avian influenza A (H5N1) challenge.

Avian influenza A subtype H5N1 virus with its recombination potential with the human influenza viruses presents a threat of producing a pandemic. The consensus is that the occurrence of such a pandemic is only a matter of time. This is of great concern, since no effective vaccine is available or can be made before the occurrence of the event. We present arguments for the use of cell mediated immunity for the prevention of the infection as well as for the treatment of infected patients. Transfer factor (TF), an immunomodulator of low molecular weight capable of transferring antigen-specific cell mediated immune information to T-lymphocytes, has been used successfully over the past quarter of a century for treating viral, parasitic, and fungal infections, as well as immunodeficiencies, neoplasias, allergies and autoimmune diseases. Moreover, several observations suggest that it can be utilised for prevention, transferring immunity prior to infection. Because it is derived from lymphocytes of immune donors, it has the potential to answer the challenge of unknown or ill-defined pathogens. Indeed, it is possible to obtain an antigen-specific TF preparation to a new pathogen before its identification. Thus, a specific TF to a new influenza virus can be made swiftly and used for prevention as well as for the treatment of infected patients.

Animals↗

PubMed2006

Morphological and phylogenetic comparisons amongst powdery mildews on Catalpa in the UK.

Three species of powdery mildew, Erysiphe elevata, E. catalpae, and Neoerysiphe galeopsidis were identified on Catalpa species in England in 2004. A new disease record, N. galeopsidis was the first Catalpa mildew to appear (in June), but it was later out-competed by E. elevata that caused the most serious damage. Both mildews also attacked C. speciosa, C. xerubescens and a new host, xChitalpa tashkentensis, a Chilopsis xCatalpa hybrid. No powdery mildew was detected on C. bungei, C. ovata, or C. fargesii. Identifications of the pathogens using morphological data were fully supported by DNA analysis yielding characteristic rDNA ITS sequences. The sequences placed E. catalpae within the E. aquilegiae clade. The sequences for E. elevata from southern England and France closely matched those from Hungary and North America, confirming the recent spread of this pathogen from the USA. It eventually overran N. galeopsidis and its sudden appearance in the UK could be due to greater aggressiveness and to the production of more ascomata especially during autumns with delayed leaf fall as in 2001. A further species, Oidium hiratae (i.e. Podosphaera sp.), though described from a 1978 UK collection on C. bignonioides, was not detected in the field.

Ascomycota↗

PubMed2004

Enhancing sensitivity of human herpes virus diagnosis with DNA microarrays using dendrimers.

DNA microarray technology has become a promising new tool for the detection and identification of viral pathogens in human plasma and cell cultures. For exploration of this technology, we have developed DNA microarrays that encode capture oligonucleotide probes for different human herpes viruses: herpes simplex virus (HSV) HSV-1, HSV-2, varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and HHV-6. The on-chip hybridization is accomplished with the PCR amplicons of the respective human herpes virus types. In this original article, we attached multiple Cy3-fluorophores to the branched 5' ends of the labeling oligonucleotide primers. For the first time, we experimentally demonstrated that the self-designed, knowledge-based, and focused microarrays specifically hybridized to fluorophore-labeled pathogenic DNAs using dendrimer technology. The fluorescence signal enhancement via the dendrimers was up to 30 times compared with the quenched single Cy3-fluorophore-labeled HSV-1 DNA. The on-chip signal-amplifying effect depended upon the number of branches and the concentration of fluorophore-labeled pathogenic DNAs. Treblers were superior to doublers, as trebler-labeled nucleic acids had fluorescence-signal-enhancing effects over a broad range of labeled DNA concentrations exemplified for the quenched single Cy3-fluorophore-labeled HSV-1 and non-quenched single Cy3-fluorophore-labeled CMV DNAs.

Blood↗

PubMed1991

Mycotic vulvovaginitis: a broad overview.

The incidence of mycotic vulvovaginitis is rising dramatically in the United States mainly because of an increase in infections caused by Candida species. Accurate diagnosis depends on culture techniques that will yield correct identification of fungal pathogen(s). Recurrences are common and require culture specimens from sexual partners and appropriate antifungal therapy. The imidazoles and more recently the broader spectrum triazoles are used for vaginal therapy.

Antifungal Agents↗

PubMed1984

Some clinical implications of recombinant DNA technology with emphasis on prenatal diagnosis of hemoglobinopathies.

Recombinant DNA technology has made possible remarkable advances in understanding the molecular genetics of human and other eucaryotic cells. This technology also has clinical applications, some of which may soon involve clinical laboratories. Restriction endonucleases and cloned DNA probes permit the direct analysis of cellular DNA to detect sequence abnormalities associated with particular genetic disorders. Use of this approach in the antenatal diagnosis of hemoglobinopathies is now possible on a routine basis. The principles behind the methods are quite general and may be applied to other hereditary diseases once suitable DNA probes become available. The same approach may be used to detect carriers of recessive gene defects and so improve genetic counselling. Other clinically related applications of recombinant DNA technology include the production of antigens for vaccine preparation and of specific human proteins (e.g. interferon and human growth hormone) for therapeutic use, as well as the use of nucleic acid hybridization for identification of microbial pathogens. It seems likely that recombinant DNA technology will, in the future, play an increasingly important role in the diagnosis, prevention and treatment of human disease.

Alleles↗

PubMed1993

Viral encephalitis.

Viral encephalitis represents an important source of morbidity and mortality worldwide. Numerous viruses possess neurovirulence, producing encephalitic disorders that usually consist of fever, headache, vomiting, altered consciousness, focal or generalized seizures, and motor dysfunction. Contemporary virologic methods frequently allow rapid and specific identification of viral pathogens, but the etiologic agent remains uncertain in 25% or more of encephalitis patients. Although acyclovir substantially reduces mortality and improves outcome for patients with herpes simplex virus encephalitis, supportive care remains the only therapy available for most patients with virus encephalitis.

Antiviral Agents↗

PubMed1981

Viruses and bacteriophages.

Many of the enteric viruses which are transmitted from person to person by the fecal-oral route are found in raw and treated wastewater, and because of their persistence under adverse conditions may also be found in slightly polluted waters. There is no routine examination procedure of water and wastewater for enteroviruses, mainly because of the cumbersome isolation techniques, high cost and the need for highly skilled laboratory personnel. Phages are specific to single species of bacteria, are known for many enteric bacteria, and are very often used for final identification of enteric pathogenic bacteria. Coliphages are prevalent in raw and treated sewage as well as in polluted water, where enteric viruses may also be found. Coliphages were often mentioned as possible viral indicators in polluted water. To be a perfect indicator, they should comply with minimum criteria as follows: (a) they should be present wherever human enteric viruses are present; (b) the coliphage numbers recovered should be equal to or larger than those of enteric viruses recovered; (c) the coliphages should be at least as resistant as enteric viruses to adverse environmental conditions; (d) isolation and quantification of the coliphage should be faster and less expensive than isolation of the enteroviruses. Comparative studies show that the coliphage to enterovirus ratio in wastewater is about 10(3):1. Levels of poliovirus 1 (attenuated) to coliphage f2 remained stable for a few months in oxidation pond effluents. f2 coliphage exhibited higher resistance to chlorination than poliovirus 1 (attenuated). When the two strains were kept in water of different quality, f2 survived longer. In addition, all coliphage counts were completed within 24 h. while those of enteroviruses required about a week. Results indicate very strongly that coliphages can be used as viral indicators and this is already the practice in a few European and other countries.

Coliphages↗