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Biomedical subjects

M Cafferkey

Publications and source records attributed to M Cafferkey.

32 records · Page 2Linked to original sources
PubMed1992

Evaluation of different solid media used for cultivation of Helicobacter (Campylobacter) pylori.

The ability of nine blood containing media to support the growth of H. pylori was compared. Eighteen strains of H. pylori isolated from antral biopsies were cultivated in two dilutions, for colony counts on the media to be tested. Columbia base chocolate agar without additives was found to be the best medium for growth of H. pylori. However, all other fresh blood containing media also supported the growth of this organism satisfactorily.

Blood↗
PubMed1991

The effect of bile acids on the growth and adherence of Helicobacter pylori.

Bile reflux gastritis occurs in the absence of Helicobacter pylori (H. pylori). The aim of this study was to see if the bile acids cheno or ursodeoxycholic acid affected the growth or adherence of H. pylori in vitro. Twenty-seven strains growth were inhibited by 0.1% chenodeoxycholic acid whereas only 11 out of the 27 were inhibited by 0.1% ursodeoxycholic acid. Growth was totally inhibited by a combination of 0.05% chenodeoxycholic acid +0.05% ursodeoxycholic acid. Chenodeoxycholic acid was a more effective inhibitor of adherence in that the number inhibited and percentage inhibition were greater than with ursodeoxycholic acid. Bile salts might be useful in the treatment of H. pylori infection.

Animals↗
PubMed1991

Infection of Waldeyer's ring: value of pernasal retropharyngeal swabs.

The value of pernasal retropharyngeal swabs in chronic adenoid and tonsillar disease was assessed in a prospective study involving 52 patients. Prior to adenoidectomy (34 patients) or adenotonsillectomy (17 patients), pernasal and tonsillar swabs were taken and the culture compared to the bacteriology profile obtained in the adenoid and tonsil tissue following surgery. The pernasal swab correctly identified 76% of pathogens isolated in the adenoid tissue. In addition, pernasal swabs forecast the presence of pathogens in 64% of core tonsil specimens, compared to an accuracy of 38% when superficial tonsil swabs were compared to the microbes in the deep tonsil. H. influenzae was the predominant organism isolated in all cultures. Our results clearly demonstrate that pernasal swabs give a representative picture of the adenoid bacterial content. Pernasal swabs are also superior to superficial tonsil swabs in indicating the deep tonsillar organisms.

Adenoidectomy↗
PubMed1990

Yersinia enterocolitica aroA mutants as carriers of the B subunit of the Escherichia coli heat-labile enterotoxin to the murine immune system.

Plasmid p5F which directs the expression of the Escherichia coli heat-labile enterotoxin B subunit (LT-B) from the ptac promoter was introduced into the attenuated Yersinia enterocolitica O:8 aroA mutant strain YAM.1. YAM.1 (p5F) expressed high levels of cell-associated and secreted LT-B in a stable fashion when grown on normal laboratory medium. The strain was used as a live oral vaccine in BALB/c mice and vaccinated mice developed high levels of gut-associated and systemic antibodies to both LT-B and the lipopolysaccharide (LPS) of the vaccine strain. Anti-LT-B and anti-LPS responses in the sera were predominantly of the IgG class whereas gut-associated antibodies were predominantly IgA. ELISPOT assays carried out on selected tissues prepared from vaccinated mice showed significant numbers of cells synthesising IgG and IgA antibodies to LT-B. These results show that Y. enterocolitica aroA mutants can be used effectively as carriers of heterologous antigens to the murine immune system.

Animals↗
PubMed1989

Cloning and characterisation of the serC and aroA genes of Yersinia enterocolitica, and construction of an aroA mutant.

A gene library of Yersinia enterocolitica 8081 was constructed in the cosmid vector pHC79. Recombinants containing the aroA gene, encoding 5-enolpyruvylshikimate 3-phosphate synthase, were identified by complementation of the aroA mutation in Escherichia coli K-12 strain AB2829. All six recombinant plasmids which complemented aroA also complemented the serC mutation in E. coli K-12 strain KL282. Tn5 mutagenesis suggested serC encoding 3-phosphoserine aminotransferase was the proximal gene in an operon with aroA. The nucleotide sequence of a 3-kb HindII-EcoRV fragment encoding the two genes was determined. The serC and aroA open reading frames contain 362 and 428 codons, respectively, and the deduced amino acid sequences share 78% and 81% homology, respectively, with the corresponding E. coli genes. Sequence inspection revealed no obvious terminators or promoters in the intergenic region. The cloned Y. enterocolitica aroA gene was inactivated in vitro and reintroduced into the parental Y. enterocolitica 8081 strain using the suicide vector pJM703.1. Stable aroA insertion mutants of Y. enterocolitica were isolated.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1989

Virulence, persistence, and immunogenicity of Yersinia enterocolitica O:8 aroA mutants.

The virulent Yersinia enterocolitica strain 8081 killed BALB/c mice within 5 days of oral infection with a 50% lethal dose of log10 7.1, whereas an aroA mutant of 8081, YAM.1, and the plasmidless variant 8081c failed to kill mice. Unlike 8081, YAM.1 and 8081c did not persist or grow in the Peyer's patches, mesenteric lymph nodes, livers, or spleens of mice. Mice immunized orally with single doses of live YAM.1 were poorly protected against a lethal 8081 challenge, whereas mice immunized with three doses of YAM.1 were moderately well protected.

Administration, Oral↗
PubMed1985

Vancomycin toxicity: a prospective study.

A prospective study of 34 patients treated with 39 courses of intravenous vancomycin, was undertaken in order to assess toxicity. Six patients received vancomycin alone and 27 courses were associated with aminoglycoside administration either concurrently or within two weeks of the first dose of vancomycin. Hearing loss was slight and uncommon; patients were unaware of its occurrence. Tinnitus and dizziness was noted by two patients and resolved on withdrawal of vancomycin. Diminution of renal function was seen both during (7%) and after (9%) vancomycin therapy. A striking feature of these patients with renal deterioration was the severity of their underlying disease. No evidence of synergistic toxicity between vancomycin and aminoglycosides was seen.

Adolescent↗
PubMed1983

Gentamicin and methicillin resistant Staphylococcus aureus in Dublin hospitals: molecular studies.

A large number of Staphylococcus aureus strains resistant to gentamicin, methicillin and other antibiotics, isolated in several Dublin hospitals during a 4-year period, were screened for plasmid DNA. Isolates assigned to four principal phage groups showed uniform plasmid profiles. A plasmid of mol. wt 21.0 x 10(6) encoding penicillin resistance was present in all isolates screened. A tetracycline resistance plasmid of mol. wt 24.0 x 10(6) was present in 40% of isolates of phage types 90 and 5/47/54/84/85 whereas a plasmid of mol. wt 3.0 x 10(6) was responsible for tetracycline resistance in isolates of phage types 77 and 85. Aminoglycoside, methicillin and erythromycin resistances were apparently not encoded on plasmids. Gentamicin resistance was transduced at low frequency between several strains of S. aureus and the resistance phenotype was due, in part at least, to the production of an inactivating enzyme.

Genes, Bacterial↗
PubMedDate not supplied

Rotavirus infection in hospitalised children: incidence and impact on healthcare resources.

BACKGROUND AND AIMS: In anticipation of vaccine development this study sought to determine the incidence, disease burden and associated financial burden of rotavirus (RV) infection, in hospitalised children. METHODS: Prospective observational study in two Dublin paediatric centres. RESULTS: Of 663 confirmed infections, 485 (73%) patients were hospitalised with community acquired (CA) RV; 178 (27%) cases were hospital acquired (HA) RV. A total of 243 (50%) children were < 12 months of age, with peak incidence in the 6 to < 12 month age group. CA RV resulted in utilisation of 2,305 bed days, with a median bed stay of three days (range 1-91), representing a minimum cost of Euro176,637 per year to the hospitals. When nosocomial spread and secondary cases are included, this increases to Euro258,695 per year. CONCLUSION: CA RV infection accounted for 1% of all admissions during the study period at a minimum cost of Euro728.40 per case. A safe and effective vaccine could reduce morbidity and advantage children by allowing redeployment of healthcare resources to other critical areas.

Child↗