Clonal relatedness.

<p>The clonal distribution of 53 <i>E</i>. <i>coli</i> strains—isolated from women with acute pyelonephritis (APN), recurrent cystitis (RC), or not symptomatic (healthy controls; CO)—was assessed by PFGE analysis. The vertical dotted line shows the three-band-difference breakpoint [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196260#pone.0196260.ref023" target="_blank">23</a>]. Four strains (APN3, APN34, CO4, and RC5) proved not to be typeable by <i>XbaI</i> macrorestriction analysis.</p

Biofilm formation, according to clinical syndrome and phylogenetic group.

<p>Strains were isolated from women with acute primitive pyelonephritis (APN), recurrent cystitis (RC), or healthy subjects (controls, CO). Biofilm forming ability onto polystyrene was spectrophotometrically assessed by crystal violet stain [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196260#pone.0196260.ref029" target="_blank">29</a>]. Phylogenetic groups were evaluated using PCR triplex assay, according to Clermont et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196260#pone.0196260.ref009" target="_blank">9</a>]: A, B1, B2, D, NT (non-typeable). Results are expressed as scatter plots, where bars indicate median values with interquartile range. Each dot is the average from two independent experiments with eight replicates of each strain per experiment (n = 16). Only biofilm-positive strains were considered since “not producer” strains had comparable prevalence both in groups and phylogroups (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196260#pone.0196260.t007" target="_blank">Table 7</a>). * <i>p</i><0.05, ANOVA + Tukey’s multiple comparison post-test.</p

Biofilm formation.

<p>Biofilm formation.</p

Virulence factor gene cluster distribution.

<p>Virulence factor gene cluster distribution.</p

Principal component analysis based on VFG detection.

<p>Three groups of subjects were enrolled: women with acute pyelonephritis (APN, n = 18), recurrent cystitis (RC, n = 19), or not symptomatic healthy controls (CO, n = 16). PC1 represent 19.2% of the data variability, whereas PC2 represents 12.8% of such variability.</p

Distribution of phylogenetic groups, according to clinical syndrome.

<p>Distribution of phylogenetic groups, according to clinical syndrome.</p

<i>In vitro</i> susceptibility to antibiotics.

<p><i>In vitro</i> susceptibility to antibiotics.</p

Phylogenetic relationships, biofilm formation, motility, antibiotic resistance and extended virulence genotypes among <i>Escherichia coli</i> strains from women with community-onset primitive acute pyelonephritis

<div><p>The present work set out to search for a virulence repertoire distinctive for <i>Escherichia coli</i> causing primitive acute pyelonephritis (APN). To this end, the virulence potential of 18 <i>E</i>. <i>coli</i> APN strains was genotypically and phenotypically assessed, comparatively with 19 strains causing recurrent cystitis (RC), and 16 clinically not significant (control, CO) strains. Most of the strains belong to phylogenetic group B1 (69.8%; <i>p</i><0.01), and APN strains showed unique features, which are the presence of phylogroup A, and the absence of phylogroup B2 and non-typeable strains. Overall, the most dominant virulence factor genes (VFGs) were <i>ecpA</i> and <i>fyuA</i> (92.4 and 86.7%, respectively; <i>p</i><0.05), and the mean number of VFGs was significantly higher in uropathogenic strains. Particularly, <i>papAH</i> and <i>malX</i> were exclusive for uropathogenic strains. APN and RC strains showed a significantly higher prevalence of <i>fyuA</i>, <i>usp</i>, and <i>malX</i> than of CO strains. Compared to RC strains, APN ones showed a higher prevalence of <i>iha</i>, but a lower prevalence of <i>iroN</i>, <i>cnf1</i>, and <i>kpsMT-II</i>. Hierarchical cluster analysis showed a higher proportion of two gene clusters (<i>malX</i> and <i>usp</i>, and <i>fyuA</i> and <i>ecpA</i>) were detected in the APN and RC groups than in CO, whereas <i>iutA</i> and <i>iha</i> clusters were detected more frequently in APN strains. The motility level did not differ among the study-groups and phylogroups considered, although a higher proportion of swarming strains was observed in APN strains. Antibiotic-resistance rates were generally low except for ampicillin (37.7%), and were not associated with specific study- or phylogenetic groups. APN and RC strains produced more biofilm than CO strains. In APN strains, <i>iha</i> was associated with higher biofilm biomass formation, whereas <i>iroN</i> and <i>KpSMT-K1</i> were associated with a lower amount of biofilm biomass. Further work is needed to grasp the virulence and fitness mechanisms adopted by <i>E</i>. <i>coli</i> causing APN, and hence develop new therapeutic and prophylactic approaches.</p></div

Biofilm formation by <i>E</i>. <i>coli</i> strains from women with acute pyelonephritis (APN), according to each virulence factor gene (VFG).

<p>The presence of VFGs was assessed by PCR. Biofilm forming ability onto polystyrene was spectrophotometrically assessed by crystal violet stain [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196260#pone.0196260.ref029" target="_blank">29</a>]. Each dot is the average from two independent experiments with eight replicates of each strain per experiment (n = 16). Horizontal bars are medians. * <i>p</i><0.05, Mann-Whitney test.</p

Additional file 1: of Prognostic value of morphologic and morphometric analyses in IgA nephropathy biopsies

Database 1. (XLS 37 kb