Proteus mirabilis isolates of different origins do not show correlation with virulence attributes and can colonize the urinary tract of mice

Abstract

Proteus mirabilis has been described as an aetiological agent in a wide range of infections, playing an important role in urinary tract infections (UTIs). In this study, a collection of P. mirabilis isolates obtained from clinical and non-clinical sources was analysed in order to determine a possible correlation between origin, virulence factors and in vivo infectivity. Isolates were characterized in vitro, assessing several virulence properties that had been previously associated with P. mirabilis uropathogenicity. Swarming motility, urease production, growth in urine, outer-membrane protein patterns, ability to grow in the presence of different iron sources, haemolysin and haemagglutinin production, and the presence and expression of diverse fimbrial genes, were analysed. In order to evaluate the infectivity of the different isolates, the experimental ascending UTI model in mice was used. Additionally, the Dienes test and the enterobacterial repetitive intergenic consensus (ERIC)-PCR assay were performed to assess the genetic diversity of the isolates. The results of the present study did not show any correlation between distribution of the diverse potential urovirulence factors and isolate source. No significant correlation was observed between infectivity and the origin of the isolates, since they all similarly colonized the urinary tract of the challenged mice. Finally, all isolates showed unique ERIC-PCR patterns, indicating that the isolates were genetically diverse. The results obtained in this study suggest that the source of P. mirabilis strains cannot be correlated with pathogenic attributes, and that the distribution of virulence factors between isolates of different origins may correspond to the opportunistic nature of the organism.

Standardization of isothermal microcalorimetry in urinary tract infection detection by using artificial urine

“…coli 0.75 ± 0.11 0.94 ± 0.13 11 0.75-1.67 Roos et al [24] E. faecalis 0.74 ± 0.10 0.95 ± 0.13 11 0.81 ± 0.05 Vebo et al [25] P. mirabilis 1.31 ± 0.04 0.53 ± 0.02 9 0.40-1.02 Sosa et al [26] S. aureus 0.56 ± 0.20 1.42 ± 0.51 9 1.41 ± 0. 21 Bonkat et al [7] AUM artificial urine medium World J Urol (2013) 31:553-557 555 growth rate was slightly higher (4-16 %), resulting in shorter generation time.…”

High Prevalence of SXT/R391-Related Integrative and Conjugative Elements Carrying bla CMY-2 in Proteus mirabilis Isolates from Gulls in the South of France

“…Although the biotic/abiotic reservoirs of resistant strains of P. mirabilis continue to be poorly known, the presence of similar clones in avian and human isolates in our study may suggest exchanges between different ecosystems (wildlife versus human). Moreover, P. mirabilis has already been described as a shuttle species between human and animal guts and water bodies (20).…”

Effect of Ibicella lutea on uropathogenic Proteus mirabilis growth, virulence, and biofilm formation

“…Nonetheless, more laborious experiments were conducted only with P. mirabilis strain Pr2921 since this strain has been extensively characterized in our laboratory [16][17][18]20].…”

“…These strains possess MR/P, PMF, and UCA fimbriae, flagella and produce hemolysin [16][17][18][19][20]. P. mirabilis strains were stored at -80 ºC in Luria-Bertani (LB) broth supplemented with 12% (v/v) glycerol and grown aerobically at 37 ºC.…”

“…Western immunoblots were performed using a 1:200 dilution in PBS-Tween 20 1% (w/v) skimmed milk of rabbit polyclonal immune sera raised against MrpA, PmfA, UcaA and native flagella [16,17,19,25]. Isogenic fimbrial mrpA, pmfA and ucaA mutants [16,17,20], were included in the Western blotting assays.…”