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Biomedical subjects

T S Elliott

Publications and source records attributed to T S Elliott.

At least 19 recordsLinked to original sources
PubMed1992

A novel electrical method for the prevention of microbial colonization of intravascular cannulae.

An electrical device designed to prevent microbial attachment to plastic intravascular cannulae is described. The device produced an electrical current (10 microA) in both carbon-impregnated and 'Hydrocath' cannulae. In-vitro models were utilized to demonstrate that the current can block several mechanisms by which microorganisms gain initial access to intravascular devices, including extra- and intra-luminal routes. The electrical system prevented organisms from traversing along both the external and internal surfaces of the cannulae. Effective prevention of cannula colonization was demonstrated subsequent to challenge with Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans. The findings suggest that the electrical device may offer in-vivo cannula protection from microbial attachment and colonization, thereby reducing the potential for infection.

Bacterial Adhesion↗
PubMed1992

Pigeons and peritonitis?

We report an outbreak of fungal peritonitis due to Candida parapsilosis in 12 patients undergoing chronic ambulatory peritoneal dialysis (CAPD). All 12 patients were treated by removal of the CAPD catheter together with systemic antifungal therapy. There were no peritonitis-related deaths. Four patients were successfully returned to CAPD at a later date. Microbiological investigation during the outbreak demonstrated colonization of various areas of the CAPD Unit and medical ward with the organism. C. parapsilosis was also isolated from pigeon guano obtained from window-sills. The number of cases of peritonitis due to this organism decreased markedly after bird-proof netting was installed. We believe that this is the first report of an outbreak of CAPD peritonitis due to faecal carriage of C. parapsilosis by pigeons.

Adult↗
PubMed1990

Identification of flagellar and associated polypeptides of Helicobacter (formerly Campylobacter) pylori.

Flagella of Helicobacter pylori were isolated from intact organisms by shearing and differential centrifugation. Treatment of the flagella with the detergent Triton X-100 removed the flagellar sheath, which was confirmed by electron microscopy, and the remaining naked flagella were shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to consist primarily of a single 54 kilodalton (kDa) polypeptide. This was confirmed by immunogold labelling and electron microscopy of detergent treated whole organisms, using a mouse antiserum specific for the 54 kDa polypeptide. Polypeptides solubilised from crude flagellar preparations by detergent treatment were found to have molecular weights of 26, 30, 58, 62, 66 and 80 kDa. These polypeptides are possible components of the flagellar sheath and they may represent outer membrane proteins, based on the assumption that the flagellar sheath is related in composition to the outer membrane of the organism. Analysis and definition of these components of the surface structures of the organism are important in understanding the interaction between the organism and its host in pathogenesis.

Bacterial Proteins↗
PubMed1990

The effect of antibiotics that inhibit cell-wall, protein, and DNA synthesis on the growth and morphology of Legionella pneumophila.

The response of Legionella pneumophila to antibiotics that inhibit cell-wall, protein and DNA synthesis was examined by electronmicroscopy, MIC estimations and viable counts. Ampicillin, cefotaxime, methicillin, erythromycin, rifampicin and ciprofloxacin, each used separately at 20 times their respective MIC values, showed activity against L. pneumophila in these studies. The inhibitors of cell-wall synthesis--ampicillin, cefotaxime and methicillin--effected the greatest bactericidal activity and induced the most extensive morphological changes, which included the formation of membranous lesions through which cytoplasmic contents were lost. In terms of ultrastructural damage and loss of viability, the inhibitors of protein and DNA synthesis were less effective than the antibiotics that acted on the microbial cell wall. Erythromycin- and rifampicin-treated cells possessed irregular membranes and were partially or fully lysed, whereas ciprofloxacin induced abnormally elongated organisms with intermittently lysed and detached inner membranes. These results illustrated the ability of antibiotics of putative clinical value, with diverse modes of action, to affect the ultrastructural cytology as well as the viability of L. pneumophila in vitro.

4-Quinolones↗
PubMed1990

The pathogenesis of urinary tract infections associated with Escherichia coli, Staphylococcus saprophyticus and S. epidermidis.

A model was developed in mice to study the pathogenesis of urinary tract infections caused by Staphylococcus saprophyticus strains LM-1 and LM-2, Escherichia coli SP444 and S. epidermidis E001. Murine urinary bladders were inoculated with 10(8) bacteria via a temporary urinary catheter and samples of urine and bladder were removed at days 1, 3, 5 and 10 after inoculation. They were examined both bacteriologically and by electronmicroscopy. Severe disruption of the urothelium was present immediately and the urothelium had become oedematous and ulcerated with increased urothelial exfoliation. Disruption of the urothelium was similar with all the four pathogens studied. The three strains of coagulase-negative staphylococci preferentially attached to the urothelial cell tight junctions and were not associated with polymorphonuclear leucocytes. In comparison, E. coli SP444 was randomly attached over the entire urothelium and was often in association with macrophages. Phagocytosis of E. coli by superficial urothelial cells also occurred.

Animals↗
PubMed1990

Review article: metronidazole and the anaerobic gut flora.

Metronidazole is a nitro-imidazole drug which was discovered nearly 30 years ago. Metronidazole has remained the mainstay of anti-anaerobic therapy following a change observation that its activity included anaerobic organisms. The predominant human reservoir of these anaerobic organisms is the gastrointestinal tract. In this review, the anaerobic flora and their pathogenic potential are described. The main characteristics of metronidazole and the role of selective decontamination of the gastrointestinal tract are also discussed.

Animals↗
PubMed1989

Effects of heparin and chlorbutol on bacterial colonisation of intravascular cannulae in an in vitro model.

An in vitro model was used to study the effects of heparinised saline, with or without the preservative chlorbutol, on the colonisation of intravascular cannulae. Chlorbutol significantly reduced cannula colonisation by Staphylococcus epidermidis. Flushing colonised cannulae with heparinised saline plus chlorbutol significantly reduced the number of organisms adhering to the inner surface of cannulae, when compared with the use of heparinised saline without preservative. Chlorbutol-preserved heparinised saline may not only maintain cannula patency by the prevention of thrombus formation, but may also reduce the incidence of bacterial colonisation of cannulae in vivo.

Bacterial Infections↗
PubMed1989

Are ECG Welsh cup electrodes effectively cleaned?

Re-usable Welsh electrocardiograph (ECG)-electrodes are potential vehicles for cross infection. This study confirmed that in-use ECG-electrodes are frequently contaminated with organisms such as coagulase-negative staphylococci and Gram-negative bacilli. The efficacy of five cleaning procedures was evaluated. Immersing the electrodes in water at 60 degrees C for one hour was the most effective method of decontamination tested, following challenge with a standardised suspension of Staphylococcus saprophyticus. Significant contamination persisted following simple cleaning measures. It is suggested that this was promoted by the inadequate removal of electrode gel which provided a protective environment for microorganisms.

Chlorhexidine↗
PubMed1989

Is resistance to novobiocin a reliable test for confirmation of the identification of Staphylococcus saprophyticus?

Staphylococcus saprophyticus, a coagulase-negative staphylococcus (CNS), causes acute urinary tract infection predominantly in young women (15-30 years). In the clinical microbiology laboratory identification and differentiation of S. saprophyticus from other CNS usually depends solely upon the demonstration of resistance to the antimicrobial agent novobiocin. Phenotypic characteristics of 36 novobiocin-resistant CNS isolated from the urine of patients with acute urinary tract infections were further analysed and the homogeneity of the isolates assessed. The organisms were speciated by the API STAPH identification system. Twenty-one isolates were S. saprophyticus (p greater than or equal to 97%), and there was one strain each of S. epidermidis, S. hominis and S. simulans (p greater than or equal to 97%). Of the remainder, three isolates were unidentifiable and a further nine had the characteristics associated with more than one species of CNS. Additional tests, including carbohydrate fermentation, antibiotic sensitivity and fluorogenic substrate utilisation, were performed on all isolates. Computer analysis of the results confirmed that testing for resistance to novobiocin selects a heterogeneous group of CNS composed of several different species.

Adolescent↗
PubMed1989

Bladder irrigation or irritation?

Exfoliation rates of urothelial cells following bladder irrigation were studied in patients with long-term indwelling catheters and chronic urinary tract infections (UTI). The irrigations were associated with an increased shedding of urothelial cells. Ultrastructural studies of these cells demonstrated increased disruption when compared with those obtained from normal subjects without catheters or chronic infection. The findings suggest that bladder irrigation further damages the already disrupted urothelium, which may in turn increase the predisposition of the bladder to the recurrent infections, commonly associated with patients who have indwelling urinary catheters. Bladder irrigation methods and the indications for their use require reassessment.

Aged↗
PubMed1988

Gastrointestinal carriage rate of Clostridium difficile in elderly, chronic care hospital patients.

The carriage rate of Clostridium difficile in patients at a chronic care hospital was determined by two point prevalence surveys at 6-monthly intervals. In the first survey C. difficile or its toxin was present in stool samples from five symptomless patients on three of the four wards studied. All of these colonized patients had been in hospital for at least 2 months, but there was no relationship between carriage of the organism and antibiotic use. When the survey was repeated 6 months later, no symptomless carriers were found but one symptomatic patient had C. difficile and its toxin present in the stool. The results suggest that C. difficile should always be considered as a possible cause of diarrhoea in long-stay hospitalized patients.

Aged↗
PubMed1988

Campylobacter pylori infection in children.

Two children with antral nodular hyperplasia and active chronic gastritis associated with Campylobacter pylori are reported. The organism was observed by scanning electron microscopy and cultured from antral biopsies obtained at endoscopy from each patient. Anti-C. pylori IgG was detected in high titre in both patients together with serum IgM in one patient. Treatment with ampicillin and a bismuth preparation resulted in total resolution of symptoms. Repeated endoscopy with antral biopsy and culture, as well as the absence of acute inflammatory changes, confirmed the eradication of the organism. Correlation of positive bacteriological cultures and serological tests with the clinical improvement related to therapy supports a causative role for C. pylori in antral lymphoid hyperplasia and antral gastritis in children.

Adolescent↗