Mathematical Analysis of Induced Antibiotic Resistance Among Uropathogenic Escherichia coli Strains.

The aim of the study was a profound insight into the antibiotic resistance development in uropathogenic Escherichia coli strains with the use of some mathematical and statistical methods. During the previous study some antibiotics (amoxicillin, ciprofloxacin, gentamycin, and tobramycin) were applied to induce the resistance of E. coli strains, which led to the generation of ∼120 derivative strains with changed antibiotic susceptibility profiles. In this work, quantitative analysis was performed based on the strains defined as values of vectors of susceptibility for all the antibiotics' use. The Pearson correlation coefficient was used to define the correlation dissimilarity (distance) of the strains, which was further applied to hierarchical clustering. Analogously, the antibiotics were presented as vectors of susceptibility values of all the investigated strains. Correlation and cluster analysis were performed for antibiotics. The hclust method from the R system with the Ward method was used as a class agglomeration method. Mathematical analysis revealed two types of statistically relevant interactions-between antibiotics and derivative strains, as well as between the effect of individual antibiotics on the bacterial strains. These observed correlations can play a potential role for modeling uropathogenic E. coli (UPEC) resistant changes, based on the particular antibiotic used to initiate resistance development, or a model helping to predict drug resistance interactions in various UPEC strains. The obtained results can lead to development of much more sophisticated mathematical models, which, in turn, can be a potentially useful tool as a drug resistance trend predictor, both for clinicians and epidemiologists.

Comparison of antibiotic resistance patterns in collections of Escherichia coli and Proteus mirabilis uropathogenic strains.

Escherichia coli and Proteus mirabilis are important urinary tract pathogens. The constant increase in the antibiotic resistance of clinical bacterial strains has become an important clinical problem. The aim of this study was to compare the antibiotic resistance of 141 clinical (Sweden and Poland) and 42 laboratory (Czech Republic) P. mirabilis strains and 129 clinical (Poland) uropathogenic E. coli strains. The proportion of unique versus diverse patterns in Swedish clinical and laboratory P. mirabilis strain collections was comparable. Notably, a similar proportion of unique versus diverse patterns was observed in Polish clinical P. mirabilis and E. coli strain collections. Mathematical models of the antibiotic resistance of E. coli and P. mirabilis strains based on Kohonen networks and association analysis are presented. In contrast to the three clinical strain collections, which revealed complex associations with the antibiotics tested, laboratory P. mirabilis strains provided simple antibiotic association diagrams. The monitoring of antibiotic resistance patterns of clinical E. coli and P. mirabilis strains plays an important role in the treatment procedures for urinary tract infections and is important in the context of the spreading drug resistance in uropathogenic strain populations. The adaptability and flexibility of the genomes of E. coli and P. mirabilis strains are discussed.