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Human infections with thymine-requiring bacteria
Abstract:
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.
Insights
Researchers identified thymine-requiring (thy-) mutants in patients treated with co-trimoxazole. These mutants may be pathogenic, with their survival potentially linked to thymine availability from cell breakdown or bacterial persistence.
Area of Science:
- Microbiology
- Clinical Medicine
- Pharmacology
Background:
- Thymine-requiring (thy-) mutants of pathogenic organisms have been isolated from patients.
- Co-trimoxazole treatment is a common factor in patients harboring these mutants.
Purpose of the Study:
- To investigate the occurrence and potential mechanisms of survival for thymine-requiring mutants in patients.
- To explore the clinical significance and pathogenicity of these thy- mutants.
Main Methods:
- Clinical case review of 16 patients with thy- mutant isolates.
- Analysis of urine samples for thymine-like compounds.
- In vitro studies observing mutant growth patterns (satellitism).
Main Results:
- Six patients' urine contained thymine-like compounds supporting thy- mutant growth.
- Potential sources of thymine include pus cell breakdown or bacterial persistence in tissues.
- Increased isolation frequency of thy- mutants, possibly due to faster secondary mutations.
Conclusions:
- Thymine-requiring mutants may be pathogenic, posing a clinical challenge.
- Alternative chemotherapy should be considered for patients with these infections.
- Further research is needed to clarify the clinical significance of thy- mutant infections.