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Biomedical subjects

R Maskell

Publications and source records attributed to R Maskell.

29 records · Page 2Linked to original sources
PubMed1978

Human infections with thymine-requiring bacteria.

Clinical details are presented of 16 patients from whom thymine-requiring (thy-) mutants of pathogenic organisms were isolated; all had been treated with co-trimoxazole. The urine of six patients infected with thy- mutants contained levels of a thymine-like compound sufficient to support their growth. This might be the result either of the breakdown of pus cells or of thymine production by living bacteria that persist in stones or scar tissue, a suggestion supported by the observation of mutant growth "in satellitism" in vitro. Since 1975 we have isolated mutants from patients who have had short courses of co-trimoxazole, in contrast to those we reported upon previously, all except one of whom had had long courses. We are now isolating thy- mutants more frequently than hitherto. Secondary mutations to a low thymine requirement may now be occurring more rapidly, thereby allowing more mutant organisms to survive. The clinical significance of infection with thy- mutants is not yet clear, but evidence is accumulating that they are pathogenic. Alternative chemotherapy is suggested for patients from whom such mutants have been isolated.

Adult↗
PubMed1977

Staphylococci as urinary pathogens.

During the course of one year all (382) strains of staphylococci isolated in significant culture from urine specimens were typed by the Baird-Parker method. Staphylococcus aureus accounted for only 63 (16%) of the infections. Novobiocin-resistant micrococcal infection occurred predominantly in young women but also in children of both sexes; it was not restricted to M3. To try to detect possible sources of micrococcal infection other than faeces the normal flora of the throat, urinary tract, and vagina of young women was studied. Novobiocin-resistant micrococci were rarely found. Previous reports that micrococci are the second commonest urinary pathogens in young women in domiciliary practice were confirmed. The laboratory records of patients with these infections suggested that they respond well to treatment and that recurrences are usually due to a different organism.

Adolescent↗
PubMed1976

Renal stones and urinary infection: a study of antibiotic treatment.

Twenty-two patients in whom renal calculi and urinary infection were closely associated were studied over two to five years. Four patients had previously had stones surgically removed, and five underwent pyelolithotomy during the course of the study. Urinary infection was treated with an appropriate antibacterial agent, and treatment was followed by long-term prophylaxis, usually with cotrimoxazole. A sterile urine was maintained for long periods in all these patients. In four patients, however, apparent stone growth occurred while the urine was sterile. On entering the study 21 of the 22 patients complained of symptoms. After treatment 19 of the 20 patients who were still attending were symptom-free. Six of the 22 patients entered the study with raised levels of serum creatinine; levels fell in four and remained raised in two. This antibacterial regimen, either alone or after surgery, will usually relieve symptoms and may prevent deterioration of renal function.

Adult↗
PubMed1976

Urinary infection in boys.A three-year prospective study.

73 boys who presented to their general practitioners over the course of one year with symptoms of urinary-tract infection and were found to have bacteriuria were referred to a three-year prospective study. This included clinical and radiological investigations and monitoring of the preputial flora and midstream-urine culture at monthyl intervals. 22 (30%) of the boys had radiological abnormalities of the urinary tract; 6 had pyelonephritic changes. Only 2 required urinary-tract surgery. Several findings of the study suggest that the natural history of the disease in boys is different from that in girls. Proteus spp.predominated as the infecting organisms. Culture of swabs from the preputial sac, and comparison with matched controls, suggested that the source of infection in boys is the prepuce or urethra rather than the bowel as in girls. Recurrence of infection, in the absence of radiological abnormality, was rare; 51 boys (70%) had no recurrence throughout the follow-up period. There was evidence that recurrence in boys is related to the persistence of gram-negative organisms in the urethra, revealed by low bacterial counts on midstream culture, and it is suggested that in boys urethral infection may be as important as bladder bacteriuria.

Bacteriuria↗
PubMed1976

Thymine-requiring bacteria associated with co-trimoxazole therapy.

Since 1971 thymine-requiring (thy-) pathogens have been isolated from the urine of 8 patients with renal calculi, and from the sputum of 1 patient with chronic chest infection. The patients had been treated with co-trimoxazole for several months before the isolation of the mutant pathogens. There was persistent pyuria in the patients with renal calculi, and purulent sputum in the patient with chronic chest infection. The mutants were identified by their inability to grow on diagnostic sensitivity test agar (D.S.T., Oxoid) which is deficient in thymine. It was found that wild-type bacteria can produce growth factors for the metabolism of the mutants in vitro, and the urine of the patients contained by thymine-like compounds. These findings indicate that thy- mutants may develop in renal calculi during co-trimoxazole therapy. Therapy should be changed to a more suitable antimicrobial as soon as possible after diagnosis of mutant infection.

Bacteria↗
PubMed1975

Urinary pathogens in the male.

Evidence is presented that the pathogens causing urinary infection in boys differ significantly from those causing infection in girls and in adult males. Studies of the prepuce floria in boys known to have had urinary infection and in matched controls suggest that the focus of infection is in the preputial sac or urethra rather than the bowel as in girls. It is suggested that the difference in infecting organisms in boys and in adult males may be related to prostatic secretion.

Adolescent↗