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At least 955 records · Page 53Linked to original sources
PubMed2001

Oligosaccharides: application in infant food.

Oligosaccharides are a complex mixture of approximately 130 compounds present in human milk. It has been shown that human milk oligosaccharides induce an increase in the number of bifidobacteria of colonic flora in breast-fed infants, accompanied with a significant reduction in the number of pathogenic potential bacteria, due to their bifidogenic activity. Complex oligosaccharides have the capacity of inhibiting the binding of pathogens to cell surface because they act as competitive receptors. They are associated with a lower risk of infections and diarrhoea and an improvement of the immune system response. Due to the decrease of the pH intestinal caused by their fermentation, oligosaccharides provoke a reduction of the flora pathogens, an increase of bifidobacteria and an increase of the availability of minerals. In the food industry, simple oligosaccharides such as fructooligosaccharides and galactooligosaccharides are used as bifidogenic oligosaccharides and some infant products contain them in the hope that this might provide some of the benefits attributed to oligosaccharides in human milk. This paper reviews characteristics of oligosaccharides, their beneficial effects and use of oligosaccharides in the food industry. In adults, the benefits of some of the oligosaccharides have been established in several clinical trials, but in infants more fundamental research is needed to establish the metabolic role of these components and the daily intake with bifidogenic activity.

Bifidobacterium↗
PubMed2000

Epidemiology of resistance to antibiotics. Links between animals and humans.

An inevitable side effect of the use of antibiotics is the emergence and dissemination of resistant bacteria. Most retrospective and prospective studies show that after the introduction of an antibiotic not only the level of resistance of pathogenic bacteria, but also of commensal bacteria increases. Commensal bacteria constitute a reservior of resistance genes for (potentially) pathogenic bacteria. Their level of resistance is considered to be a good indicator for selection pressure by antibiotic use and for resistance problems to be expected in pathogens. Resistant commensal bacteria of food animals might contaminate, like zoonotic bacteria, meat (products) and so reach the intestinal tract of humans. Monitoring the prevalence of resistance in indicator bacteria such as faecal Escherichia coli and enterococci in different populations, animals, patients and healthy humans, makes it feasible to compare the prevalence of resistance and to detect transfer of resistant bacteria or resistance genes from animals to humans and vice versa. Only in countries that use or used avoparcin (a glycopeptide antibiotic, like vancomycin) as antimicrobial growth promoter (AMGP), is vancomycin resistance common in intestinal enterococci, not only in exposed animals, but also in the human population outside hospitals. Resistance genes against antibiotics, that are or have only been used in animals, i.e. nourseothricin, apramycin etc. were found soon after their introduction, not only in animal bacteria but also in the commensal flora of humans, in zoonotic pathogens like salmonellae, but also in strictly human pathogens, like shigellae. This makes it clear that not only clonal spread of resistant strains occurs, but also transfer of resistance genes between human and animal bacteria. Moreover, since the EU ban of avoparcin, a significant decrease has been observed in several European countries in the prevalence of vancomycin resistant enterococci in meat (products), in faecal samples of food animals and healthy humans, which underlines the role of antimicrobial usage in food animals in the selection of bacterial resistance and the transport of these resistances via the food chain to humans. To safeguard public health, the selection and dissemination of resistant bacteria from animals should be controlled. This can only be achieved by reducing the amounts of antibiotics used in animals. Discontinuing the practice of routinely adding AMGP to animal feeds would reduce the amounts of antibiotics used for animals in the EU by a minimum of 30% and in some member states even by 50%.

Animal Feed↗
PubMed2002

Periodontal diseases and HIV infection.

The workshop considered six related questions about periodontal changes seen in HIV infection. 1) To what extent are specific periodontal changes associated with HIV? 2) Are conventional periodontal diseases modified by HIV infection? The changes associated with HIV appear to be modified presentations of conventional diseases. Research should identify initiation and progression factors for necrotizing diseases. 3) What is the role of geography and transmission groups? These questions cannot be answered without greater standardisation of research methods. 4) Has the epidemiology of these changes changed with the advent of new therapies? The data required to answer this question should be available soon but this question is irrelevant to the vast majority of people with HIV. 5) What pathogens are involved in periodontal changes seen in HIV infection? The role of Candida spp. and other potential pathogens requires further investigation. 6) What management protocols are suitable for the periodontal diseases? The significance of periodontal diseases among people with HIV in developing countries is not known. Further research is needed of the effectiveness of interventions especially necrotizing disease in developing countries. The quality of research of these diseases would be enhanced by standardized approaches. A list of relevant variables might prevent their omission from studies.

Antiretroviral Therapy, Highly Active↗
PubMed2002

Incidence and clinical significance of nasal and pericatheter colonization by Gram-negative bacteria among patients undergoing chronic peritoneal dialysis.

BACKGROUND: Nasal and pericatheter colonization by Staphylococcus aureus portends an increased risk of peritonitis and exit-site infection for peritoneal dialysis (PD) patients. The aim of the present study was to examine the incidence of colonization by other peritoneal pathogens, and more specifically by Gram-negative bacteria (GNB), among PD patients, and to disclose its potential correlation with PD-related infections. METHOD: Over a 3-year period, we prospectively screened 152 PD patients and 99 partners every other month for nasal and pericatheter bacterial colonization (total follow-up for patients 3182 months). We performed 1089 studies in patients and 561 in partners. RESULTS: Although S. aureus and coagulase-negative Staphylococcus spp. predominated both in patients and partners, we recovered GNB from 15.8% (nares) and 22.4% (pericatheter) of the patients and from 29.3% of the partners. Most isolations of GNB were transient and only 7.2% of the patients and 7.1% of the partners had the same GNB isolated in at least two controls from the same sampling site. Older age, male gender, longer follow-up on PD, previous immunosuppressive therapy, low socioeconomic conditions, and a high global incidence of peritonitis were predictive of colonization by GNB. Previous pericatheter mupirocin therapy was also associated with later colonization by GNB. Nasal or pericatheter colonization by bacteria other than S. aureus, particularly GNB, had a poor predictive power for PD-related infections. CONCLUSION: Nasal and pericatheter bacterial colonization is protean in PD patients and their partners, and includes the significant presence of potentially pathogenic GNB. Colonization by GNB was not clearly associated with an increased risk of peritonitis or exit-site infection in these patients.

Adolescent↗
PubMed1993

Torulopsis glabrata in the neonate: an emerging fungal pathogen.

Fungi are becoming increasingly common nosocomial pathogens in the neonatal intensive care patient. The fungus Torulopsis glabrata, a common skin inhabitant, is a potential pathogen in the high-risk neonate. In this report we have reviewed the cases of two infants in which systemic T glabrata infection was diagnosed. One patient survived without apparent sequelae; the other died before diagnosis and initiation of therapy. Five other cases of systemic infection by T glabrata in neonates have been reported previously, with only one survivor. Early recognition and treatment of this nearly uniformly fatal infection is imperative.

Candidiasis↗
PubMed2006

Mitochondrial abnormalities in patients with LHON-like optic neuropathies.

PURPOSE: To investigate certain biochemical and molecular characteristics of mitochondria in patients with Leber hereditary optic neuropathy (LHON)-like optic neuropathies. METHODS: Patients who had LHON-like optic neuropathies in both eyes were selected from neuro-ophthalmology clinics. Evaluation included clinical examination, neuroimaging, and assessment of several mitochondrial parameters in the blood, including sequencing the entire mitochondrial (mt)DNA coding region, measuring relative mtDNA content, studying mitochondrial respiratory function in some patients, and sequencing the OPA1 and OPA3 genes. RESULTS: Thirty-five patients (21 men and 14 women; average age at onset 19.0 +/- 8.7 years) met inclusion and exclusion criteria for LHON-like optic neuropathies with median visual acuity approximately 20/200. Other hereditary retinopathies and optic neuropathies were unlikely because of inclusion and exclusion criteria, because ERGs were normal, and because no patient had pathogenic sequence changes in the OPA1 or OPA3 genes. Compared with control subjects, these patients had more potentially pathogenic nonsynonymous mtDNA changes, greater relative mtDNA content (P < 0.001), and less mitochondrial respiratory activity (P < 0.001). Only six patients (17%) had primary LHON mutations; however, even the 29 patients without primary LHON mutations had significant evidence of mitochondrial abnormalities. Mitochondrial haplogroup distribution was similar in patients and control subjects. CONCLUSIONS: Primary LHON mutations are less common in patients with LHON-like optic neuropathy selected from a clinical setting than in patients with LHON from multigenerational families. The results suggest that mitochondrial dysfunction plays a role in this type of optic neuropathy whether or not primary LHON mutations are present. This information has implications for diagnostic testing and for future investigations into mechanisms of disease.

Adolescent↗
PubMed2000

Comparison of conventional and molecular methods for the detection of bacterial pathogens in sputum samples from cystic fibrosis patients.

The nature of the micro-flora present in sputa of six different cystic fibrosis (CF) patients was assessed using routine microbiological culture and molecular methods. Bacterial genes for the small subunit ribosomal RNA (ssu rDNA) were specifically amplified from DNA extracted from the sputum samples, cloned and characterised by hybridisation and DNA sequencing. A large number of clones from six sputa were screened. Initially, oligonucleotide hybridisation was performed with five probes, specific for Gram-positives and Gram-negatives in general and the main pathogens for the CF patient (Staphylococcus aureus, Pseudomonas aeruginosa and Haemophilus influenzae). For a single sputum sample, the results were fully congruent when culture and molecular methods were compared. In the other five sputa, discrepancies for S. aureus and/or H. influenzae were documented. Although S. aureus DNA and H. influenzae DNA was detected in three and four sputa, respectively, strains could not be cultured. Although the PCR approach is not capable of distinguishing viable from dead bacteria, all of the CF patients had a history of S. aureus infections, while one of the CF patients once had cultivable H. influenzae in the sputum as well. A number of clones for probe-unidentified Gram-negative or Gram-positive bacterial species were further analysed by sequencing and additional potential pathogens were identified. Although routine culture of sputum frequently points to mono-specific exacerbations, our molecular data indicate that the other CF-related pathogens appear to be persistently present as well. We conclude that routine culture for bacterial pathogens from CF sputa yields limited microbiological information since it frequently fails to identify a number of pathogenic bacterial species that are potentially present in a viable status in the lungs of these patients.

Adult↗
PubMed1998

Characterization of two avian reoviruses that exhibit strain-specific quantitative differences in their syncytium-inducing and pathogenic capabilities.

We previously proposed that the conservation of the nonessential syncytium-inducing phenotype among all reported avian reovirus (ARV) isolates may reflect a mechanism for enhanced virus dissemination in vivo, which in turn could contribute to the natural pathogenicity of ARV. Direct testing of this hypothesis has been hampered by the lack of available virus strains with defined differences in their fusion-inducing capability. We now report on the characterization of two ARV strains, ARV-176 and ARV-138, that exhibited strain-specific differences in their fusogenic properties, which correlated with their pathogenic potential in embryonated eggs. Moreover, both virus strains possessed similar replicative abilities in cell culture, suggesting that the weakly fusogenic ARV-138 virus is specifically inhibited in its syncytium-inducing ability. To test the use of these viruses for reassortant studies aimed at assessing the role of cell fusion in viral pathogenesis, a preliminary genetic analysis was undertaken using a monoreassortant that contained nine genome segments from the parental ARV-138 virus and the S1 genome segment from the highly fusogenic and pathogenic ARV-176 parental virus. The monoreassortant possessed the full fusogenic potential of the ARV-176 parental virus and displayed enhanced embryo pathogenicity, providing the first genetic evidence implicating the ARV S1 genome segment in both syncytium formation and viral pathogenesis.

Animals↗
PubMed2002

The immune-enhancing effects of dietary fibres and prebiotics.

The gastrointestinal tract is subjected to enormous and continual foreign antigenic stimuli from food and microbes. This organ must integrate complex interactions among diet, external pathogens, and local immunological and non-immunological processes. It is critical that protective immune responses are made to potential pathogens, while hypersensitivity reactions to dietary antigens are minimised. There is increasing evidence that fermentable dietary fibres and the newly described prebiotics can modulate various properties of the immune system, including those of the gut-associated lymphoid tissues (GALT). This paper reviews evidence for the immune-enhancing effects of dietary fibres. Changes in the intestinal microflora that occur with the consumption of prebiotic fibres may potentially mediate immune changes via: the direct contact of lactic acid bacteria or bacterial products (cell wall or cytoplasmic components) with immune cells in the intestine; the production of short-chain fatty acids from fibre fermentation; or by changes in mucin production. Although further work is needed to better define the changes, mechanisms for immunomodulation, and the ultimate impact on immune health, there is convincing preliminary data to suggest that the consumption of prebiotics can modulate immune parameters in GALT, secondary lymphoid tissues and peripheral circulation. Future protocols on the physiological impact of consuming prebiotics should be designed to include assessments of the gut microflora, gut physiology and the function and composition of the various regions of GALT.

Dietary Fiber↗
PubMed1986

Septic shock in obstetrics.

Septic shock in the obstetric population remains an uncommon yet potentially lethal complication of infection. Effective therapy mandates early recognition and aggressive intervention. Although numerous similarities exist in comparison to the nonobstetric patient, differences in potential pathogens and alterations in physiologic parameters should be kept in mind. In addition, the antepartum subject carries with her another potentially viable human being who deserves consideration. Optimal therapy should be directed at reestablishing an effective intravascular volume, maintaining adequate oxygen delivery to peripheral and central tissues, and the initiation of appropriate broad-spectrum antimicrobial agents to eradicate the causative pathogens.

Anti-Bacterial Agents↗
PubMed2001

Enhanced gene expression of chemokines and their corresponding receptors in mononuclear blood cells in chronic heart failure--modulatory effect of intravenous immunoglobulin.

OBJECTIVES: We sought to study the gene expression of chemokines and their corresponding receptors in mononuclear blood cells (MNCs) from patients with chronic heart failure (CHF), both of which were cross-sectional and longitudinal studies during therapy with intravenous immunoglobulin (IVIg). BACKGROUND: We have recently demonstrated that IVIg improves left ventricular ejection fraction (LVEF) in patients with CHF. Based on the potential pathogenic role of chemokines in CHF, we hypothesized that the beneficial effect of IVIg may be related to a modulatory, effect on the expression of chemokines and their receptors in MNCs. METHODS: We examined: 1) the gene expression of C, CC and CXC chemokines and their receptors in MNCs from 20 patients with CHF and 10 healthy blood donors; and 2) the expression of these genes in MNCs from 20 patients with CHF randomized in a double-blind fashion to therapy with IVIg or placebo for 26 weeks. RESULTS: Our main findings in CHF were: 1) markedly raised gene expression of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and interleukin (IL)-8; 2) enhanced gene expression of their corresponding receptors; 3) modulation in a normal direction of this abnormal chemokine and chemokine receptor gene expression during IVIg, but not during placebo therapy; 4) down-regulation of MIP-1alpha, MIP-1beta and IL-8 during IVIg at the protein level in plasma; and 5) a correlation between down-regulation of MIP-1alpha gene expression and improved LVEF during IVIg therapy. CONCLUSIONS: Our results further support a pathogenic role for chemokines in CHF and suggest that IVIg may represent a novel therapeutic approach, with the potential to improve LVEF in patients with CHF, possibly by modulatory effects on the chemokine network.

Aged↗
PubMed1994

Two-year study of endemic enteric pathogens associated with acute diarrhea in New Caledonia.

A longitudinal study of diarrheal disease among patients of all ages with acute diarrhea was carried out in New Caledonia from January 1990 to December 1991. Stool samples from 2,088 diarrheal patients were examined for parasites, rotavirus, and bacterial pathogens. Potential sources of contamination (drinking water, seawater and bovine and porcine feces) were investigated. One or more enteric pathogens were identified in 41.8 and 40.6% of the persons with diarrhea, in 1990 and 1991, respectively. Salmonella spp., Shigella spp., HEp-2 cell adherent Escherichia coli (diffuse adherent and enteroaggregative), enteropathogenic E. coli (EPEC) (EPEC adherence factor-positive strains belonging to classical serotypes), localized adherent E. coli (non-EPEC), and enterotoxigenic E. coli were the frequently identified enteropathogenic bacteria. Other major enteropathogens were Entamoeba histolytica and Giardia lamblia. Campylobacter jejuni, Clostridium difficile, Clostridium perfringens, Yersinia enterocolitica, and rotavirus were isolated from only a few patients. No Vibrio spp., Aeromonas spp., Plesiomonas spp., Shiga-like-toxin-producing E. coli, enterohemorrhagic E. coli, or enteroinvasive E. coli were identified. Shiga-like toxin I-producing E. coli were present in adult bovines and calves, and heat-stable enterotoxin II-producing enterotoxigenic E. coli were found in pigs.

Acute Disease↗
PubMed2006

Cardiac syndrome X in women: the role of oestrogen deficiency.

Cardiac syndrome X (CSX), defined as typical exertional chest pain, a positive response to stress testing, and normal coronary arteriograms, encompasses different pathogenic subgroups. Both cardiac and non-cardiac mechanisms have been suggested to play a pathogenic role, and it has been shown that the syndrome is associated with myocardial ischaemia in at least a proportion of patients. Radionuclide myocardial perfusion defects, coronary sinus oxygen saturation abnormalities and pH changes, myocardial lactate production and stress-induced alterations of cardiac high energy phosphate have been reported in CSX patients, suggesting an ischaemic origin for their symptoms. Microvascular abnormalities often caused by endothelial dysfunction appear to be responsible for myocardial ischaemia in these patients. CSX is more prevalent in women than in men, and the majority of women with CSX are peri- or post-menopausal. Thus oestrogen deficiency has been suggested to have a pathogenic role in CSX. Additional factors such as abnormal pain perception may also contribute to the genesis of chest pain in patients with angina and normal coronary angiograms. The management of this syndrome is difficult because of the heterogeneity of pathogenic mechanisms and uncertainties as to its origin. This article discusses the problem of CSX in women, the potential pathogenic role of oestrogen deficiency, and practical clinical management.

Endothelium, Vascular↗
PubMed1990

Infections due to Corynebacterium group D2. Report of a case.

Corynebacterium group D2 is a gram-positive bacillus easily identified in clinical microbiology laboratories. However, this organism is often disregarded as a skin and mucous contaminant. The Spanish literature has recently described Corynebacterium group D2 as a urinary pathogen in a specific patient population. We report a case of Corynebacterium group D2 infection to illustrate the potential pathogenicity and clinical presentation of infection due to this organism in the United States.

Aged↗
PubMed1986

Identification and its vicissitudes in the psychoses. The importance of the concept of the 'maddening object'.

This paper describes 'psychotizing bonds' in terms of identification processes, the way they function in the constitution of the psychic apparatus and their relation to the deficient self. The author relates the pathogenic potentiality of the psychotic nuclei with the tendency of psychotic disorganization to be irreversible. Psychotic regression is considered in terms of pathogenic identification with forms of ego and superego functioning that belong to the primitive parental objects of infancy. Whereas normogenic identifications structure the subject's own ego resources, the pathogenic identifications which appear in the psychotic transference, form bonds that stifle spontaneity and force the self to be transformed into the other. These ideas lead thus to the concept of the 'maddening object'. Finally, the pathogenic identifications in the psychoanalytic process are examined. The patient should be 'rescued' from these bonds linking the self with the maddening objects. The analyst must hold the conviction that a virtual and potential subject exists in the analysand, in spite of his psychotic condition. The deficient self which becomes manifest during the moments of dis-identification must be assisted.

Adult↗
PubMed2004

[West Nile virus. Prevalence and significance as a zoonotic pathogen].

The spread of West Nile virus (WNV) in North America since 1999 has reawakened concern about this pathogen in Europe. WNV can cause West Nile fever in humans, and in a small proportion (around 1 in 150) the disease can take a severe course associated with symptoms of the central nervous system (encephalitis) and even death, particularly in older patients (>70 years). In contrast to the USA, where the virus has spread from New York thronghout the continent to the west coast, only temporally and regionally limited outbreaks of WNV infections have been observed in Europe since the 1950s. Birds serve as the reservoir for WNV and the transmission of the virus occurs predominantly via mosquitoes. Ornithophilic mosquitoes transmit the virus amongst the bird population while those mosquito species that feed on both birds and mammals can transmit the pathogen also to humans. However, mammals are considered to be blind alleys that do not contribute to the epidemic spread of the pathogen. The differences so far observed between the epidemics in North America and in Europe might be explained by the following considerations: Europe has long had contact with WNV-endemic areas in Africa via migratory birds, whereas the pathogen was first imported into the USA in 1999 where it has infected a "naive" bird population. It is possible that the strain presently spreading through the USA is highly pathogenic, whereas strains of varying pathogenic potential circulate in Africa. This could resulut in a natural immunization of the bird population through contact to strains of low pathogenicity. The possibility of a natural resistance in European birds is also being considered since these animals have been confronted with the pathogen for long periods of time. Investigations into the prevalence and incidence of WNV infections in German bird populations as well as in dead end hosts such as humans and horses should provide information regarding the potential risk represented by WNV.

Animal Migration↗
PubMed2002

Microbial source tracking: state of the science.

Although water quality of the Nation's lakes, rivers and streams has been monitored for many decades and especially since the passage of the Clean Water Act in 1972, many still do not meet the Act's goal of "fishable and swimmable". While waterways can be impaired in numerous ways, the protection from pathogenic microbe contamination is most important for waters used for human recreation, drinking water and aquaculture. Typically, monitoring methods used for detecting potential pathogenic microorganisms in environmental waters are based upon cultivation and enumeration of fecal indicator bacteria (i.e. fecal coliforms, E. coli, and fecal enterococci). Currently, there is increasing interest in the potential for molecular fingerprinting methods to be used not only for detection but also for identification of fecal contamination sources. Molecular methods have been applied to study the microbial ecology of environmental systems for years and are now being applied to help improve our waters by identifying problem sources and determining the effect of implemented remedial solutions. Management and remediation of water pollution would be more cost-effective if the correct sources could be identified. This review provides an outline of the main methods that either have been used or have been suggested for use in microbial source tracking and some of the limitations associated with those methods.

Electrophoresis, Gel, Pulsed-Field↗
PubMed2003

Occult herpes family viral infections are endemic in critically ill surgical patients.

OBJECTIVE: Herpes family viruses have been recognized as pathogens for many years in immunosuppressed transplant or human immunodeficiency virus patients, but they have garnered little attention as potential pathogens in the nonimmunosuppressed critically ill. The objective of this study was to define the prevalence of and risk factors for development of herpes family virus infection in chronic critically ill surgical patients. DESIGN: Prospective epidemiologic study. SETTING: A 38-bed surgical intensive care unit in a major university hospital. PATIENTS: Nonimmunosuppressed intensive care unit patients in intensive care unit for >/=5 days. INTERVENTIONS: None; patients received no antiviral treatment during the study. MEASUREMENTS AND MAIN RESULTS: Weekly cultures for cytomegalovirus (CMV) and herpes simplex virus, viral serologies, and T-cell counts were performed. The prevalence (95% confidence interval) of positive respiratory cultures for herpes simplex or CMV was 35% (22-49%); 15% (5-25%) cultured positive for CMV, 23% (11-35%) cultured positive for herpes simplex virus, and one patient's respiratory secretions culturing positive for both CMV and herpes simplex virus. The prevalence of CMV viremia was only 5.8% (1-10%). CMV+ patients had longer hospital admissions, intensive care unit admissions, and periods of ventilator dependence than CMV- patients, despite having comparable severity of illness scores. CMV+ patients also had significantly higher numbers of blood transfusions, prevalence of steroid exposure, and prevalence of hepatic dysfunction, and all were immunoglobulin G positive at the beginning of the study. In contrast, herpes simplex virus-positive patients had lengths of hospital admissions, lengths of intensive care unit admissions, and periods of ventilator dependence comparable with patients without viral infections (p >.05). CONCLUSIONS: There is a significant prevalence (22-49%) of occult active herpes family viruses in chronic critically ill surgical patients. The clinical significance of these viral infections is unknown, although CMV+ patients have significantly higher morbidity rates than CMV- patients. Several factors suggest pathogenicity, but further study is needed to define causality.

APACHE↗