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Introduction: Extraintestinal Escherichia coli infections represent a growing public health threat, However, current studies often overlook important factors such as temporal patterns of infection, phylogenetic and clonal background, or the host gut E. coli population, despite their likely significance. Methods: In this study, we analyzed >7000 clinical E. coli isolates from patients at the Minneapolis Veterans Affairs Health Care System (2012-2019), and concurrent fecal E. coli from uninfected veterans. We assessed phylogenetic group distribution, membership in selected sequence types (STs), and subsets thereof--including the pandemic, resistance-associated ST131-H30R, and ST1193 lineages--and strain type, as defined by pulsed-field gel electrophoresis. We then analyzed these features alongside the temporal patterns of infection in individual hosts. Results: The H30R lineage emerged as the leading lineage, both overall and among fluoroquinolone-resistant isolates, with ST1193 following among fluoroquinolone-resistant isolates. Recurrences were common, occurring in 31% of subjects and 41% of episodes, and often multiple and delayed/prolonged (up to 23 episodes per subject; up to 2655d post-index). Remarkably, these recurrences typically involved the subject's index strain (63% of recurrences), even when affecting extra-urinary sites. ST131, H30R, ST1193, and fluoroquinoloneresistant strains generally caused significantly more recurrences than did other strains, despite similar recurrence intervals. ST131 strain types shifted significantly over the study period. Infection-causing strains were commonly detectable in host feces at times other than during an infection episode; the likelihood of detection varied with surveillance intensity and proximity to the infection. H30R and ST1193 were prominent causes of fecal-clinical clonal overlap. Discussion: These findings provide novel insights into the temporal and clonal characteristics of E. coli infections in veterans and support efforts to develop anti-colonization interventions. [ABSTRACT FROM AUTHOR]

An exceptional gut-colonizing ability may underlie the dramatic epidemiological success of the multidrug-resistant H30R subclone of Escherichia coli sequence type 131 (O25b:K+:H4). In order to inform the development of colonization-preventing measures, we studied systemic immune correlates of H30R intestinal colonization. Human volunteers' fecal samples were screened for H30R by selective culture and PCR. Subjects were assessed by enzyme immunoassay for serum levels of anti-O25 IgG (representing H30R) and anti-O6 IgG (representing non-H30 E. coli generally), initially and for up to 14 months. Whole blood was tested for the antigen-stimulated release of IFNγ, TNFα, IL-4, IL-10, and IL-17 after incubation with E. coli strains JJ1886 (H30R; O25b:K+:H4) or CFT073 (non-H30; O6:K2:H1). Three main findings were obtained. First, H30R-colonized subjects had significantly higher anti-O25 IgG levels than controls, but similar anti-O6 IgG levels, suggesting an IgG response to H30R colonization. Second, anti-O25 and anti-O6 IgG levels were stable over time. Third, H30R-colonized subjects exhibited a lower TNFα and IL-10 release than controls in response to strain JJ1886 (H30R) relative to strain CFT073 (non-H30R), consistent with TNFα hypo-responsiveness to H30R possibly predisposing to H30R colonization. Thus, H30R-colonized hosts exhibit a sustained serum anti-O25 IgG response and an underlying deficit in TNFα responsiveness to H30R that could potentially be addressed for colonization prevention. [ABSTRACT FROM AUTHOR]

To determine whether bacterial contamination of rider's hands is less with a novel ergonomic wheelchair (EW) than a standard wheelchair (SW). After wheelchair hand rims were disinfected, volunteers wearing nitrile gloves propelled each wheelchair through a standardised "run" in hospital. Post-run cultures were obtained from riders' gloved hands. Bacterial hand counts were compared between runs matched by rider (same rider, different chairs) or time (different riders in each chair, running concurrently), and overall. Minneapolis Veterans Affairs Health Care System (MVAHCS), a large tertiary care facility. Eleven employee volunteers. EW, as compared with SW. With SW, co-location of hand rims and tyres potentially exposes the user's hands to tyres, which risks contaminating the user's hands with ground-source bacteria. Our novel ergonomic wheelchair (EW) separates drive wheel and hand rims, potentially reducing hand contamination. Bacterial hand counts. Post-run bacterial hand counts were over 10-fold lower with the EW than the SW. This was true (i) when the same rider tested both chairs sequentially (n = 8 pairs) (median counts, 40 vs. 1030; p = 0.008), (ii) when different riders tested the two chairs concurrently (n = 9 pairs) (median counts, 40 vs. 660; p = 0.004), and (iii) overall (median counts, 40 [n = 9 runs] vs. 550 [n = 10 runs]; p < 0.001). Separation of wheelchair hand rims from tyres significantly reduces bacterial hand contamination. Reduced hand contamination could decrease bacterial infections and dissemination of resistant bacteria, warranting further study. The novel design of the ergonomic wheelchair, removing the push rim from proximity to the wheelchair tyre, keeps the hands of wheelchair users cleaner. The re-design of the standard manual wheelchair was implemented initially to improve shoulder ergonomics during manual wheelchair propulsion and has the added benefit of reduction in the transfer of bacteria from floors to hands for manual wheelchair users. Since the ergonomic wheelchair has the potential to decrease rates of bacterial infection in manual wheelchair users, further testing is warranted. [ABSTRACT FROM AUTHOR]

The prevalence of resistance to fluoroquinolones and extended-spectrum cephalosporins in Escherichia coli has increased dramatically over the past decade. This increase is largely the result of the widespread emergence of [...]

The food supply, including poultry products, may transmit antimicrobial drug-resistant Escherichia coli to humans. To assess this hypothesis, 931 geographically and temporally matched E. coli isolates from human volunteers (hospital [...]

Extended-spectrum cephalosporin-resistant Escherichia coli (ESCREC) are a growing threat. Leading ESCREC lineages include sequence type ST131, especially its (blaCTX-M-15-associated) H30Rx subclone and (blaCTX-M-27-associated) C1-M27 subset within the H30R1 subclone. The comparative activity against such strains of alternative antimicrobial agents, including the recently developed aminoglycoside plazomicin, is undefined, so was investigated here. We assessed plazomicin and 11 comparators for activity against 216 well-characterized ESCREC isolates (Minnesota, 2012–2017) and then compared broth microdilution MICs with phylogenetic and clonal background, beta-lactamase genotype (blaCTX-M; group 1 and 9 variants), and co-resistance. Percent susceptible was > 99% for plazomicin, meropenem, imipenem, and tigecycline; 96–98% for amikacin and ertapenem; and ≤ 75% for the remaining comparators. For most comparators, MICs varied significantly in relation to multiple bacterial characteristics, in agent-specific patterns. By contrast, for plazomicin, the only bacterial characteristic significantly associated with MICs was ST131 subclone: plazomicin MICs were lowest among O16 ST131 isolates and highest among ST131-H30R1 C1-M27 subclone isolates. Additionally, plazomicin MICs varied significantly in relation to resistance vs. susceptibility to comparator agents only for amikacin and levofloxacin. For most study agents, antimicrobial activity against ESCREC varied extensively in relation to multiple bacterial characteristics, including clonal background, whereas for plazomicin, it varied only by ST131 subclone (C1-M27 isolates least susceptible, O16 isolates most susceptible). These findings support plazomicin as a reliable alternative for treating ESCREC infections and urge continued attention to the C1-M27 ST131 subclone. [ABSTRACT FROM AUTHOR]

Background: Emerging antimicrobial-resistant Escherichia coli represent mainly the nested (fluoroquinolone-resistant [FQR]) H30R and H30Rx subclones within sequence type 131 (ST131). Intestinal colonization and within-household transmission may underlie H30R's emergence.Methods: We screened fecal samples from 741 volunteers (383 veterans, 358 household members, including pets) for ST131 and FQR E. coli (FQREC) and used molecular profiling to resolve unique strains. Selected strains underwent PCR-based detection of phylogroups, sequence types (STs), H30, H30Rx, and 53 virulence genes (VGs). Within-household strain sharing was compared with household, host, and bacterial characteristics. Fecal isolates were compared with clinical isolates.Results: Colonization prevalence was 5.1% for H30R, 8% for ST131 (67% FQREC), and 10% for FQREC (52% ST131). ST131 isolates exhibited more VGs than non-ST131 isolates. Strain sharing (27% of multisubject households, 18% of corresponding subjects) was associated with the elderly, FQREC, H30R, H30Rx, ST73, and specific VGs. Fecal ST131 and FQREC isolates resembled contemporaneous and historical clinical isolates according to all studied traits.Conclusions: Veterans and their human household members commonly carry and extensively share FQREC, predominantly H30R, thereby likely facilitating the ST131 pandemic. Strain sharing corresponds with multiple bacterial characteristics, including FQ resistance and specific VGs, which may promote intestinal colonization and/or host-to-host transmission. [ABSTRACT FROM AUTHOR]