Joint Modeling of Resistance to Six Antimicrobials in Urinary Escherichia coli Isolates in Quebec, Canada.

Empirical treatment of urinary tract infections should be based on susceptibility profiles specific to the locale and patient population. Additionally, these susceptibility profiles should account for correlations between resistance to different types of antimicrobials. We used hierarchical logistic regression models to investigate geographic, temporal, and demographic trends in resistance to six antimicrobials in community-acquired and nosocomial urinary E. coli isolates from three communities in the province of Quebec, Canada, procured between April 2010 and December 2017. A total of 74,986 community-acquired (patient age, ≥18 years) and 4,384 nosocomial isolates (patient age, ≥65 years) were analyzed. In both community-acquired and nosocomial isolates, we found geographic variation in the prevalence of resistance. Male sex (community-acquired hierarchical mean odds ratio [OR], 1.24; 95% credible interval [CI], 1.02 to 1.50; nosocomial hierarchical mean OR, 1.16, 95% CI, 0.92 to 1.41) and recent hospitalization (community-acquired hierarchical mean OR, 1.49; 95% CI, 1.33 to 1.66; nosocomial hierarchical mean OR, 1.31; 95% CI, 0.99 to 1.78) were associated with a higher risk of resistance to most types of antimicrobials. We found distinct seasonal trends in both community-acquired and nosocomial isolates, but only community-acquired isolates showed a consistent annual pattern. Ciprofloxacin resistance increased sharply with patient age. We found clinically relevant differences in antimicrobial resistance in urinary E. coli isolates between locales and patient populations in the province of Quebec. These results could help inform empirical treatment decisions for urinary tract infections. In the future, similar models integrating local, provincial, and national resistance data could be incorporated into decision support systems for clinicians.

Escherichia coli antimicrobial susceptibility profile and cumulative antibiogram to guide empirical treatment of uncomplicated urinary tract infections in women in the province of Québec, 2010-15.

OBJECTIVES: Empirical treatment of uncomplicated urinary tract infections (UTIs) in women should be based on local susceptibility data. We aimed to generate regional and provincial cumulative antibiograms combining data from different laboratory information systems and determine the impact of basic patient characteristics on susceptibility results. METHODS: All positive urine samples for Escherichia coli obtained from women aged 18-65 years old in outpatient settings between 1 April 2010 and 31 March 2015 from four hospitals in Quebec, Canada, were included. The cumulative antibiogram for ciprofloxacin, nitrofurantoin and trimethoprim/sulfamethoxazole was calculated. A clinically significant difference in susceptibility profile was defined as factor(s) that lowered the susceptibility proportion below 80%. RESULTS: A total of 36 293 positive urine cultures were analysed. In the last year of the study, the proportion of susceptibility for ciprofloxacin, nitrofurantoin and trimethoprim/sulfamethoxazole was 90.3%, 95.4% and 81.9%, respectively. The susceptibility proportion was <80% for trimethoprim/sulfamethoxazole in the Montreal region (73.4%; 95% CI 71.1%-75.9%), whereas it remained >80% for the other regions. A significant decrease in susceptibility with time was identified for ciprofloxacin (92.1%-90.3%, P < 0.001) and nitrofurantoin (97.1%-95.4%, P < 0.001). Increasing age, recent hospitalization and site of collection were associated with an increase in resistance for certain antibiotics. CONCLUSIONS: Overall, all first-line antimicrobials remain acceptable choices for empirical treatment of uncomplicated UTIs in women in Quebec. The regional variability in susceptibility data within a single province emphasizes the importance of local susceptibility data to inform the development of empirical treatment guidelines for UTIs.

Performance of MycAssay Aspergillus DNA real-time PCR assay compared with the galactomannan detection assay for the diagnosis of invasive aspergillosis from serum samples.

Invasive aspergillosis (IA) is a major problem in the immunocompromised population, and its diagnosis is difficult due to the low sensitivity of available tests. Detection of Aspergillus nucleic acid by polymerase chain reaction (PCR) in serum samples is a promising diagnostic tool; however, use of multiple "in-house" methods precludes standardization. The first commercial PCR assay, MycAssay Aspergillus (Myconostica, Ltd), became available recently, and its performance in the diagnosis of IA was evaluated and compared with the galactomannan (GM) assay. Serum samples obtained from patients with hematological cancer were tested retrospectively with MycAssay Aspergillus PCR. Per-episode and per-test analyses were undertaken with 146 sera from 35 hematological patients. Sixteen patients had proven or probable IA and 19 had possible or no IA. In per-episode analysis, MycAssay Aspergillus had a sensitivity of 43.8% (95% confidence interval [CI], 19.8%-70.1%) and a specificity of 63.2% (95% CI, 38.4%-83.7%) for IA diagnosis. In per-test analyses, MycAssay Aspergillus had a lower specificity than the GM assay (83.3% vs. 93.1%, P = 0.04). The addition of PCR to routine clinical practice would have permitted the diagnosis of one additional probable IA in our cohort. Use of PCR instead of GM assay would have delayed the diagnosis in two cases. Aspergillus DNA detection by PCR with serum specimens using MycAssay showed a lower specificity than the GM assay and was associated with a low sensitivity for IA diagnosis. More studies are needed to determine the exact role of MycAssay in IA diagnosis in patients with hematological malignancy.

Influenza viral RNA detection in blood as a marker to predict disease severity in hematopoietic cell transplant recipients.

Influenza RNA in blood (viremia) was detected in 9 of 79 (11.4%) hematopoietic cell transplant recipients with influenza, and was less frequently observed in patients with upper respiratory tract disease only and more frequently in patients infected with 2009 pandemic influenza A/H1N1 strain (versus seasonal strains). Viremia increased the risk of progression to lower respiratory tract disease (LRD), hypoxemia, respiratory failure, and overall and influenza-related death. Among patients with LRD, viremia was associated with increased hazards of overall and influenza-associated death (hazard ratio 3.5, 1.1-12). Thus, influenza viremia may serve as marker for overall poor outcome.

H275Y mutant pandemic (H1N1) 2009 virus in immunocompromised patients.

Most oseltamivir-resistant pandemic (H1N1) 2009 viruses have been isolated from immunocompromised patients. To describe the clinical features, treatment, outcomes, and virologic data associated with infection from pandemic (H1N1) 2009 virus with H275Y mutation in immunocompromised patients, we retrospectively identified 49 hematology-oncology patients infected with pandemic (H1N1) 2009 virus. Samples from 33 of those patients were tested for H275Y genotype by allele-specific real-time PCR. Of the 8 patients in whom H275Y mutations was identified, 1 had severe pneumonia; 3 had mild pneumonia with prolonged virus shedding; and 4 had upper respiratory tract infection, of whom 3 had prolonged virus shedding. All patients had received oseltamivir before the H275Y mutation was detected; 1 had received antiviral prophylaxis. Three patients excreted resistant virus for >60 days. Emergence of oseltamivir resistance is frequent in immunocompromised patients infected with pandemic (H1N1) 2009 virus and can be associated with a wide range of clinical disease and viral kinetics.

Differences in clinical outcomes after 2009 influenza A/H1N1 and seasonal influenza among hematopoietic cell transplant recipients.

It is not known whether pandemic 2009 influenza A/H1N1 (2009 H1N1) leads to more serious disease than seasonal influenza in hematopoietic cell transplant (HCT) recipients. In a retrospective study in HCT recipients with virologically proven influenza virus infection, a total of 161 HCT recipients (18 2009 H1N1, 103 seasonal influenza A, and 40 seasonal influenza B) were analyzed. In multivariable analyses, more patients with 2009 H1N1 had lower respiratory tract disease (LRD), hypoxemia, and prolonged viral shedding compared with seasonal influenza A. Seasonal influenza A and B outcomes were similar. There was no difference in overall and influenza-associated mortality among influenza virus types. Both early and delayed administration of antiviral therapy was shown to be beneficial in terms of decreased rates of development of LRD, although earlier intervention appeared to be more effective. Profound lymphopenia and lack of early antiviral therapy were associated significantly with LRD, hypoxemia, and death. High-dose corticosteroid treatment (≥ 1 mg/kg) given at the time of influenza diagnosis was associated with a reduced risk for mechanical ventilation. Thus, our data suggest that infection with 2009 influenza A/H1N1 resulted in more severe respiratory disease in HCT recipients compared with seasonal influenza.

Impact of corticosteroid treatment and antiviral therapy on clinical outcomes in hematopoietic cell transplant patients infected with influenza virus.

The impact of cytokines induced during influenza infection has been described, but the effect of corticosteroids on clinical outcomes is unclear. Although antiviral therapy has been well studied in immunocompetent subjects, few data exist on its clinical efficacy in immunocompromised populations. Data from 143 hematopoietic cell transplant recipients with documented seasonal influenza infection were reviewed to examine the impact of different corticosteroid regimens and antiviral therapy on clinical outcomes. In multivariable analyses, there was no observed difference between patients who received no, low doses (<1 mg/kg/day), or high doses (≥ 1 mg/kg/day) of corticosteroids with regard to the development of lower respiratory tract disease (LRD), hypoxemia, need for mechanical ventilation, or death. However, treatment with high-dose steroids was associated with a trend toward prolonged viral shedding (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.0-11; P = .05). In multivariable analyses, antiviral therapy initiated to treat upper respiratory tract infection (URI) was associated with fewer cases of LRD (OR, 0.04; 95% CI, 0-0.2; P < .01) and fewer hypoxemia episodes (OR, 0.3; 95% CI, 0.1-0.9; P = .03). Our results suggest that corticosteroids are not associated with adverse clinical outcomes in hematopoietic cell transplant recipients infected with influenza, although use of higher doses may delay viral clearance. Antiviral therapy initiated during the URI phase reduced the risk of LRD and hypoxemia.

Screening for polyomavirus associated nephropathy in renal transplantation with blood viral load measurement.

BACKGROUND: Polyomavirus associated nephropathy (PVAN) is an important cause of graft failure in the renal transplant population. It has been shown that viremia precedes PVAN, suggesting that measurement of blood viral load could be used for PVAN screening. OBJECTIVES: To verify the utility of BK virus (BKV) blood viral load measurement for PVAN screening in the renal transplant population, establish a threshold value, and determine the sensitivity and specificity of the test. STUDY DESIGN: We developed a real-time PCR assay for BKV blood viral load measurement and included this assay in the PVAN screening protocol of the renal transplant recipients of our institution. We report results for 60 patients who had a blood viral load measurement concomitantly with an allograft biopsy with immunohistochemistry for polyomavirus. RESULTS: 14 patients were found to have a PVAN on allograft biopsy together with a viral load above 3.0x10(3)copies/ml. None of the patients with a viral load under 3.0x10(3)copies/ml had a PVAN on allograft biopsy. The area under the receiver operating characteristic (ROC) curve was 0.95 (95% CI: 0.91-1.00) and using a threshold value of 3.0x10(3)copies/ml yielded a sensitivity of 100% (95% CI: 76.8-100%) and a specificity of 89.6% (95% CI: 77.3-96.5%) for PVAN screening. CONCLUSIONS: BKV blood viral load measurement is sensitive and specific for PVAN screening when a threshold value is precisely determined.

Yeast enhancer of polycomb defines global Esa1-dependent acetylation of chromatin.

Drosophila Enhancer of Polycomb, E(Pc), is a suppressor of position-effect variegation and an enhancer of both Polycomb and trithorax mutations. A homologous yeast protein, Epl1, is a subunit of the NuA4 histone acetyltransferase complex. Epl1 depletion causes cells to accumulate in G2/M and global loss of acetylated histones H4 and H2A. In relation to the Drosophila protein, mutation of Epl1 suppresses gene silencing by telomere position effect. Epl1 protein is found in the NuA4 complex and a novel highly active smaller complex named Piccolo NuA4 (picNuA4). The picNuA4 complex contains Esa1, Epl1, and Yng2 as subunits and strongly prefers chromatin over free histones as substrate. Epl1 conserved N-terminal domain bridges Esa1 and Yng2 together, stimulating Esa1 catalytic activity and enabling acetylation of chromatin substrates. A recombinant picNuA4 complex shows characteristics similar to the native complex, including strong chromatin preference. Cells expressing only the N-terminal half of Epl1 lack NuA4 HAT activity, but possess picNuA4 complex and activity. These results indicate that the essential aspect of Esa1 and Epl1 resides in picNuA4 function. We propose that picNuA4 represents a nontargeted histone H4/H2A acetyltransferase activity responsible for global acetylation, whereas the NuA4 complex is recruited to specific genomic loci to perturb locally the dynamic acetylation/deacetylation equilibrium.