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Sources of intrapopulation variability in causative agents of nosocomial infection
Abstract:
The mechanisms of heterogeneity of S. aureus and P. aeruginosa populations of pathological foci in patients with wound, traumatic, and burns infections were studied. It has been established that populations of the mentioned species in the sources of infection (patients and carriers) are pronouncedly heterogeneous and objects in the external environment serving as factors of transmission are contaminated with a whole complex of diverse variants. The conclusion can therefore be drawn that the first source of intrapopulation variability of wound populations of microbes is the presence of varying strains and variants in the infecting dose of the causative agent. The second source consists in repeated superinfection (immigration) of pathological processes by new, usually nosocomial, strains and variants of the same species with their subsequent selection during the patients' stay in the health-service establishment. Other sources of population variability, such as mutation and recombination, are of minor importance. With respect to the obtained results it is necessary to increase the volume of the representative sample of cultures in bacteriological diagnosis of open processes, to protect them reliably from superinfection, to follow up dynamically changes in the composition of causative agents and to provide for suitable correction of chemotherapy.
Insights
Staphylococcus aureus and Pseudomonas aeruginosa wound infections show significant microbial heterogeneity. This variability stems primarily from the initial infecting dose and subsequent hospital-acquired infections, not mutation.
Area of Science:
- Microbiology
- Infectious Diseases
- Clinical Diagnostics
Background:
- Wound, traumatic, and burn infections are often caused by heterogeneous populations of Staphylococcus aureus and Pseudomonas aeruginosa.
- Understanding the sources of microbial heterogeneity is crucial for effective treatment and infection control.
Purpose of the Study:
- To investigate the mechanisms driving the heterogeneity of S. aureus and P. aeruginosa populations in pathological foci.
- To identify the primary sources of microbial variability in wound infections.
Main Methods:
- Analysis of microbial populations from pathological foci in patients with wound, traumatic, and burns infections.
- Identification and characterization of different strains and variants of S. aureus and P. aeruginosa.
Main Results:
- Microbial populations of S. aureus and P. aeruginosa in infection sources (patients, carriers) and environmental factors are highly heterogeneous.
- The infecting dose containing diverse microbial variants is the primary source of intrapopulation variability.
- Repeated superinfections with new strains, particularly nosocomial ones, significantly contribute to variability during patient hospitalization.
Conclusions:
- Mutation and recombination play a minor role in the observed population variability.
- Recommendations include increasing sample sizes in diagnostics, preventing superinfections, monitoring microbial changes, and adjusting chemotherapy accordingly.