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Biomedical subjects

J R Govan

Publications and source records attributed to J R Govan.

82 records · Page 5Linked to original sources
PubMed1975

Mucoid strains of Pseudomonas aeruginosa: the influence of culture medium on the stability of mucus production.

Mucoid strains of Pseudomonas aeruginosa isolated from the respiratory tract of patients with cystic fibrosis (CF), those obtained from non-CF patients, and those obtained in vitro by the action of phage, were found to be stable in their mucoid colonial form when serially subcultured on deoxycholate-citrate agar. The ability of anionic, cationic and neutral surfactants to stabilise mucus production is described. The possible importance of dipalmitoyl lecithin as a stabilising agent for mucus production in vivo is considered, with particular reference to the role of mucoid P. aeruginosa in CF disease.

Acetylcysteine↗
PubMedDate not supplied

Rational parameters for antibiotic therapy in patients with cystic fibrosis.

Data from the literature and the authors' experiences were used to review aspects of antibiotic therapy of patients with cystic fibrosis; attention was paid to in vitro antimicrobial susceptibility tests and assessment of therapy directed against mucoid Pseudomonas aeruginosa. The heterogeneity of P. aeruginosa within single sputa with respect to antibiotic susceptibility is stressed. Quantitative viable counts of bacteria based on an analysis of homogenised sputum is recommended. The mode of in vivo growth of mucoid P. aeruginosa is discussed to explain the survival of hypersusceptible P. aeruginosa in vivo, and the clinical benefit observed in the absence of a significant reduction of the pathogen. The value of ceftazidime in the treatment of exacerbations due to Haemophilus influenzae is emphasised. The social benefits from oral administration of ciprofloxacin also emphasises that the patient's quality of life must also be considered.

Anti-Bacterial Agents↗
PubMedDate not supplied

Heterogeneity and reduction in pulmonary clearance of mucoid Pseudomonas aeruginosa.

Mucoid, alginate-producing Pseudomonas aeruginosa isolated from patients with cystic fibrosis were studied to determine the extent of heterogeneity of the isolates within individual sputa. Considerable heterogeneity involving cultural requirements for mucoid colonial growth was observed, and sensitivity to the beta-lactam antibiotic carbenicillin was also variable. For determining if the presence of alginate increased pulmonary survival of the bacteria, groups of rats were infected by transtracheal instillations of equivalent numbers of mucoid or nonmucoid P. aeruginosa, and survival was measured as the percentage of inoculum colony-forming units cultured from lung homogenates. Increased pulmonary survival of mucoid P. aeruginosa was observed in animals killed 3 hr or 6 hr after infection with unwashed bacteria. No difference in survival between mucoid and nonmucoid cells was observed when bacteria were washed prior to instillation. It was concluded that a single mucoid colony isolated from a sputum does not fully represent the population of mucoid P. aeruginosa within the patient and that pulmonary killing of mucoid P. aeruginosa can be less efficient than that for nonmucoid strains.

Animals↗