Correlation of pathogenic factors with antimicrobial resistance of clinical Proteus mirabilis strains

Abstract

AbstractProteus mirabilis is the third most common etiological factor of the urinary tract infection (UTI). It produces urease, which contributes to the formation of crystalline biofilm, considered to be one of the most important virulence factors of P. mirabilis strains, along with their ability to swarm on a solid surface. The aim of this study was to analyze the pathogenic properties of two selected groups of clinical P. mirabilis isolates, antimicrobial-susceptible and multidrug-resistant (MDR), collected from hospitals in different regions in Poland. The strains were examined based on virulence gene profiles, urease and hemolysin production, biofilm formation, and swarming properties. Additionally, the strains were differentiated based on the Dienes test and antibiotic susceptibility patterns. It turned out that the MDR strains exhibited kinship more often than susceptible ones. The strains which were able to form stronger biofilm had broader antimicrobial resistance profiles. It was also found that the strongest swarming motility correlated with susceptibility to most antibiotics. The correlations described in this work encourage further investigation of the mechanisms of pathogenicity of P. mirabilis.Author summaryProteus mirabilis is widely widespread in environment but also it is responsible for most Proteus infections, especially in human urinary tracts. They cause complicated, persistent infections especially due to the ability to form urinary stones. The clinical importance of P. mirabilis have been described in the literature many times. However, the role of pathogenic features with correlation to drug resistance require further investigation. In this research we analyzed thee virulence factors in relation to drug resistance of clinical P. mirabilis strains isolated from urine. The virulence genes, ureolytic and hemolytic activity, biofilm formation, swarming growth and strains kindship were analyzed. The most important observation was that the strains exhibited a stronger territorialism were kindred to a lower number of other strains, formed weaker biofilm and exhibited a lower resistance to antibiotics. Furthermore, we proved that the strains which were more likely to mutual growth, they were also less similar in the drug resistance profile but exhibited a higher resistance to antibiotics, which can be beneficial for different bacteria living together. We believe that P. mirabilis with strong territorialism can represent a wild group of strains with poor experience of antibiotic pressure. The environmental influence (toxins, antibiotics, bacterial neighbors) stimulates the development of a less dispersed community with stronger biofilm, exchange of genes and increase of resistance to antibiotics.