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PubMed2004

Gastrointestinal disorders: are health care professionals missing zoonotic causes?

Acute gastrointestinal disorders (AGIDs) of presumed infectious origin are common illnesses and among the most frequent infective diseases referred to hospital. Much is known about the diagnosis and aetiology of AGIDs, but relatively little work appears to have been done regarding the assessment of relevant general practitioner (GP) history-taking and the potential for under-recognition of sources such as zoonoses. Established sources of zoonosis (for example exotic pet-keeping, farmyards and zoological parks) seem either rarely considered or annotated. Surveillance of food-borne illness and its aetiology attracts rapidly increasing attention in the public health community and these infections have been targeted for serious reduction. Zoonoses may present as food-borne illness. The aim of this study was to assess the potential for under-ascertainment and under-reporting of important sources of gastrointestinal infection. The study examined history-taking habits among GPs with reference to their general scope for either detecting or missing diverse sources of acute gastrointestinal infections. From a medical practice perspective, more specific identification of pathogenic factors may potentially promote wider preventive measures by alerting the public to unconsidered or recurrent problems. The study was conducted at a busy British health centre that currently accommodates eight GPs and several training personnel. The health centre has approximately 12,000-13,000 patients. The patient presentation records and GP notes were accessed via the health centre's computer database. Data on acute gastrointestinal disorders were obtained using the Read codes for both 'diarrhoea of presumed infectious origin' (DPI) and 'gastroenteritis of presumed infectious origin' (GPI). The first 35 cases were selected from the DPI list (10% of 'names'), and the first 24 cases were selected from the GPI list (10% of 'names'). Symptoms were unspecified in 11 out of the 24 GPI presentations compared to four unspecified out of 35 DPI presentations. Potentially significant history was unspecified in 22 out of the 24 GPI presentations compared to 27 unspecified out of 35 DPI presentations. Among potential sources of infection are: pet shops; exotic and domestic pets; farm animals/environments; and zoos and other wildlife centres. These established sources of potential infection are, however, only infrequently enquired into by GPs; thus their pathological significance may be easily overlooked. By using a standard setting 'pathogen source questionnaire' GPs might alert themselves to domestic or wider media of infection as well as enable more precise cues regarding when to sample and when to refer to hospital.

Acute Disease↗
PubMed1997

Lung mucus: a clinician's view.

Respiratory mucus represents the products derived from secretion of the submucosal glands and the goblet cells. Accumulation of mucus in the airway tree may be caused by an increased volume of mucus produced, and also by decreased clearance due to defects in the ciliary clearance apparatus. Hypersecretion of mucus contributes to the morbidity of airway diseases by predisposing patients to respiratory infections, and contributing to airflow obstruction and to patients' discomfort. There is a significant association between chronic production of mucus and an increased risk of mortality. Also the degree of airway obstruction is related to the physical properties of the sputum. Observation of chronic bronchitic sputum can reveal important clinical information concerning the type and level of the inflammatory process, the physical properties of the material, the extent of bronchial mucosal damage, and the identification of pathogenic microorganisms that may be present. The management of mucous hypersecretion can be undertaken in two main ways: firstly, improved clearance by physical methods; and, secondly, by pharmacological methods.

Airway Obstruction↗
PubMed2005

Genetical and functional investigation of fliC genes encoding flagellar serotype H4 in wildtype strains of Escherichia coli and in a laboratory E. coli K-12 strain expressing flagellar antigen type H48.

BACKGROUND: Serotyping of O-(lipopolysaccharide) and H-(flagellar) antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli. At present, 176 O- and 53 H-antigens are described for E. coli which occur in different combinations in the strains. The flagellar antigen H4 is widely present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. RESULTS: The complete nucleotide sequence of fliC genes present in E. coli reference strains U9-41 (O2:K1:H4) and P12b (O15:H17) was determined and both were found 99.3% (1043 of 1050 nucleotides) identical in their coding sequence. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli strains reacting with H4 antiserum were investigated. Nucleotide sequencing of complete fliC genes of six E. coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. coli K-12 strain JM109 which encodes flagellar type H48. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. CONCLUSION: The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. coli strains which were isolated at different time periods and geographical locations. Our expression studies show for the first time, that flagellins of different molecular weigh are functionally expressed and coassembled in the same flagellar filament in E. coli.

Amino Acid Sequence↗
PubMed2006

The bacterial weaponry: lessons from Shigella.

Shigella, a Gram-negative bacterial species of the family Enterobacteriaceae, causes bacillary dysentery in humans, an acute rectocolitis that reflects the capacity of the microorganism to disrupt, invade, and cause the inflammatory destruction of the intestinal epithelium. Here, the pathogenesis of Shigella infection is analyzed in the context of the disruption of the homeostatic balance that protects the gut against inflammation in the presence of its commensal flora. Thus a unified view by which enteroinvasive pathogens allow identification of key signalling molecules and pathways involved in the regulation of intestinal inflammation, thereby providing keys to understand inflammatory bowel diseases (IBDs) such as Crohn's disease and ulcerative colitis.

Dysentery, Bacillary↗
PubMed1990

Diagnosing periodontal diseases.

At present, the diagnosis of periodontal disease requires a clinical evaluation of the patient including visual findings, the use of the periodontal probe, and radiographs. No test is available to evaluate disease activity. In specific cases, adjunctive procedures may also be useful. The identification of pathogenic microorganisms may aid in evaluating the periodontal status of special patients. However, these are not required for an adequate diagnosis of the common adult form of chronic periodontitis.

Humans↗
PubMed2005

State of the art and science of endodontics.

BACKGROUND: Advances in the art and science of endodontics have facilitated better understanding of disease processes and have led to development of treatment modalities aimed to restore health to the pulp and periradicular tissues. This article presents a summary of both basic and clinical breakthroughs in endodontics. RESULTS: The author indicates that, on the basis of the reviewed literature, pulp and periradicular diseases are primarily microbial. Basic research has led to development of methodologies that have allowed for specific and accurate identification of pathogens that are likely to cause persistent infections. Close examination of clinical data shows that meticulous débridement of the infected root canal system will result in a high probability of successful treatment outcome. Progress in visualization, mechanical and chemical disinfection, and biological seal of portals of entry will improve quality of care further. CONCLUSIONS AND CLINICAL IMPLICATIONS: A better understanding of the pathogenesis of pulp and periradicular diseases, inflammation and healing, as well as of pain pathways, will improve patient care and result in preservation of natural tissues.

Dental Pulp Diseases↗
PubMed2003

Hexaplex PCR for rapid detection of virulence factors.

PCR technology has emerged as a basic tool in biological research and in the detection of infectious organisms. It has the potential to provide information on a number of toxins and virulence factors, as well as allowing species identification of pathogens. Multiplex PCR assays are becoming prevalent for the simultaneous detection of toxins, virulence factors and pathogens in clinical and environmental specimens. This review will discuss the hexaplex PCR assay, its application and future directions.

Animals↗
PubMed2004

Genetic variability analysis among clinical Candida spp. isolates using random amplified polymorphic DNA.

The patterns of genetic variation of samples of Candida spp. isolated from patients infected with human immunodeficiency virus in Vitória, state of Espírito Santo, Brazil, were examined. Thirty-seven strains were isolated from different anatomical sites obtained from different infection episodes of 11 patients infected with the human immunodeficiency virus (HIV). These samples were subjected to randomly amplified polymorphic DNA (RAPD) analysis using 9 different primers. Reproducible and complex DNA banding patterns were obtained. The experiments indicated evidence of dynamic process of yeast colonization in HIV-infected patients, and also that certain primers are efficient in the identification of species of the Candida genus. Thus, we conclude that RAPD analysis may be useful in providing genotypic characters for Candida species typing in epidemiological investigations, and also for the rapid identification of pathogenic fungi.

AIDS-Related Opportunistic Infections↗
PubMed1997

Therapeutic antibiotics in animal feeds and antibiotic resistance.

Recent statutory changes involving animal drugs are expected to facilitate the therapeutic use of antibiotics in animal feeds in the United States of America. The use of antibiotics in animal feeds is controversial due to the potential development of resistant bacterial pathogens in food-producing animals which are exposed to the antibiotics and the resultant public health risk. Zoonotic micro-organisms can be transmitted to humans through contact with animal populations, either directly or through the consumption of contaminated food. Recommendations to address the public health concerns include the strengthening of professional education in the areas of infectious diseases and the appropriate selection and use of antimicrobial agents, the development of a comprehensive food safety education programme for food-animal veterinarians and animal producers, and the development of surveillance programmes to monitor antimicrobial resistance among zoonotic pathogens. Early identification of emerging resistance can facilitate a timely and appropriate public health response.

Animal Feed↗
PubMed2003

Molecular relatedness between isolates Yersinia pseudotuberculosis from a patient and an isolate from mountain spring water.

A 40-yr-old buddhist monk was admitted to the hospital with abdominal pain, fever, and confusion. He had a history of drinking untreated mountain spring water in his temple, and experienced the above symptoms for several days before admission. In past medical history, he had suffered from hepatic cirrhosis. Yersinia pseudotuberculosis was isolated from his blood and ascitic fluid. The mountain spring water that he had ingested was cultivated and Y. pseudotuberculosis was also isolated. For identification of pathogenic Y. pseudotuberculosis, each isolate from the three sources (blood, ascitic fluid, and drinking water) was also analysed for the inv gene for Y. pseudotuberculosis and the virF gene for virulent plasmid by PCR. All strains were positive for both the virF and the inv genes and also positive for autoagglutination test. For relationship study, each isolate from the three sources was also analysed with serotyping and restriction endonuclease analysis of virulence plasmid DNA (REAP) using BamHI. All belonged to the serotype 4b and REAP pattern D. Thus, all these findings supported that the mountain spring water was the source of the Y. pseudotuberculosis infection in this case.

Adhesins, Bacterial↗
PubMed1998

Antibiotic use at a pediatric age.

For infections in infants and children, the successful antibiotic treatment depends primarily on rapid diagnosis of the disease, identification of pathogenic microorganisms, and appropriate application of specialized pharmacokinetic and pharmacodynamic knowledge of antibiotics in children. In infants and children, the absorption, distribution, metabolism, and excretion of drugs may differ considerably in comparison with adults. Because of known toxicity, certain drugs such as chloramphenicol in high doses, the sulfonamides, and tetracycline should not be used in neonates. In this article, we describe these peculiarities of children and discuss the proper use of antibiotics in children.

Anti-Bacterial Agents↗
PubMed1996

The management of common infections in ambulatory children.

Antimicrobial therapy of infection in ambulatory children remains the cornerstone of the pediatrician's practice. Despite a cornucopia of newer antimicrobial agents, the older "tried and true" drugs continue to be favored based on their history of effectiveness, lack of toxicity, and low price. It also is clear that the widespread use of antimicrobial agents has contributed to the development of resistance. We must reevaluate our antimicrobial use so that we only treat infections likely to benefit from antimicrobials. Better diagnostic techniques should be developed for rapid and accurate identification of pathogens. Finally, alternative therapeutic strategies should be investigated, such as shorter courses of treatment or use of vaccines, to lessen the selective pressure on the microbial flora. To fail to meet this challenge will mean the more rapid transition into the "postantibiotic era".

Ambulatory Care↗
PubMed2003

Complementarity-determining region 3 spectratyping analysis of the TCR repertoire in multiple sclerosis.

Multiple sclerosis (MS) is considered to be an autoimmune disease mediated by T cells reactive with Ags in the CNS. Therefore, it has been postulated that neuroantigen-reactive T cells bearing particular types of TCRs are expanded clonally during the course of the disease. However, there is a controversy with regard to the TCR usage by T cells associated with the development of MS. By the use of complementarity-determining region 3 spectratyping analysis that is shown to be a useful tool for identification of pathogenic TCR in autoimmune disease models, we tried to demonstrate that spectratype was T cells bearing particular types of TCR are activated in MS patients. Consequently, it was found that Vbeta5.2 were often oligoclonally expanded in peripheral blood of MS patients, but not of healthy subjects. Sequence analysis of the complementarity-determining region 3 region of spectratype-derived TCR clones revealed that the predominant TCR clone was different from patient to patient, but that similar results were obtained in a patient examined at different time points. More importantly, examination of cerebrospinal fluid T cells and longitudinal studies of PBLs from selected patients revealed that Vbeta5.2 expansion was detectable in the majority of patients examined. These findings suggest that Vbeta5.2 spectratype expansion is associated with the development of MS and that TCR-based immunotherapy can be applicable to MS patients if the TCR activation pattern of each patient is determined at different stages of the disease.

Adolescent↗
PubMed2001

Prevalence of causative organisms in corneal ulcers seen at Sekuru Kaguvi Eye Unit, Harare, Zimbabwe.

OBJECTIVE: To investigate the prevalence of organisms causing corneal ulcers, determine frequency of ocular risk factors and assess the value of Gram stain in initial identification of pathogens. DESIGN: A descriptive cross sectional study. SETTING: Sekuru Kaguvi Eye Unit at Parirenyatwa Group of Hospitals in Harare, Zimbabwe. MATERIALS AND METHODS: We enrolled 43 patients with corneal ulcers for the study. Demographic data was obtained, measurement of visual acuity was done by Snellen's chart and a Topcon Slit Lamp was used to determine the characteristics of ulcers for all the patients. Corneal scrapings were obtained and examined by microscopy and culture methods to determine etiologic organisms. Positivity rates between Gram stain and culture methods were compared. MAIN OUTCOME MEASURES: Prevalence of different bacterial isolates in corneal ulcers, risk factors to infection and laboratory methods used for detection. RESULTS: Gram-positive cocci were the most prevalent organisms found (54%) followed by E. coli (18%). Pseudomonas, Klebsiella and Narcodia constituted about 9% each. Trauma, use of traditional eye medicine and previous viral disease were the common risk factors. CONCLUSION: Bacteria were the only organisms identified and Gram-positive cocci were the most common isolates. Gram stain of corneal smears was not reliable in initial recognition of offending pathogens.

Adult↗
PubMedDate not supplied

[The development of an original reagent for the rapid determination of the deoxyribonuclease (DNAse) activity of microorganisms].

The DN-ase test is the most important tests used for identification of pathogenic microorganisms. But often this test is not accessible for microbiology laboratories because of its high prices. The author elaborated a new original preparation for the rapid determination of the DN-ase activity, which permits a 350-400 fold reduction of the cost/test ratio. Moreover, the technique procedure is essentially simplified; there is not necessary to cultivate the microbial strain in nutritional media before testing and thus the necessity of laboratory sterile materials is also diminished. These advantages were achieved by using Ustilago maydis chlamidospores, ("bisorbent MN-21") as laboratory reagent for DN-ase activity.

Bacteria↗
PubMedDate not supplied

Preparation of a heterogeneous conjugate to detect Mycoplasma iowae by immunofluorescence.

Fluorescent antibody technique has been used as a diagnostic tool for the identification of pathogenic avian Mycoplasma species. Fluorescein-conjugated antisera for Mycoplasma iowae prepared from rabbit hyperimmune serum against one serotype (I) has not always been reliable, giving false-negative results. A fluorescein-conjugated antisera was prepared with antibody against the six identified serotypes (I, J, K, N, Q, and R) that comprise the species M. iowae. This heterogeneous conjugate was used to positively identify M. iowae in field isolates and lab strains, while maintaining specificity. Polymerase chain reaction specific for M. iowae was used to determine specificity.

Animals↗
PubMed1975

Vibrio parahaemolyticus -- a marine pathogen detected in South African coastal waters.

Vibrio parahaemolyticus has been detected in the Natal and Eastern Cape costal water of South Africa. As a proven cause of gastro-enteritis or a potential pathogen to humans, it is an organism of importance to public health. Outlines of the history, pathogenicity and identification are given, as well as the results of the local investigation of this organism.

Culture Media↗