Ranjani Somayaji

Human infections due to Staphylococcus pseudintermedius, an emerging zoonosis of canine origin: report of 24 cases.

BACKGROUND Staphylococcus pseudintermedius has been recently identified as a novel species within the genus Staphylococcus, and is commonly associated with infections in dogs. Currently, there are few reports of human infections due to this bacterium. OBJECTIVE To use a population-based approach to describe the characteristics of human S. pseudintermedius infections in a large Canadian healthcare region. METHODS All adult cases aged ≥18 years identified at a large regional laboratory from April 1, 2013 to April 1, 2015 who had at least one positive culture for S. pseudintermedius were retrospectively reviewed. A combination of phenotypic methods, mass spectrometry (i.e., MALDI-TOF), and cpn60 sequencing were used to identify S. pseudintermedius. Chart review was conducted, and cases were analysed descriptively. RESULTS Twenty-seven isolates of S. pseudintermedius from 24 human cases were included for analysis. 58.3% were male with median age of 61 years (IQR 55-70.5). Most patients [22 (92.1%)] had confirmed contact with dogs at time of infection. S. pseudintermedius was isolated in 18 cases (75.0%) of skin and soft tissue infections (SSTI), and 2 invasive cases (8.3%) including a prosthetic joint and bloodstream infection. The other 4 patients were considered to be colonized (skin - 3; lung - 1). Methicillin resistance was identified in 3 cases with 6 total isolates (22.2%); multi-drug resistance was also demonstrated commonly. CONCLUSION S. pseudintermedius is most commonly associated with SSTIs in humans. Transmission probably occurs from a pet dog. Species-level identification of S. pseudintermedius is important due to the high prevalence of antibiotic resistance, particularly to methicillin.

Cognitive load imposed by knobology may adversely affect learners' perception of utility in using ultrasonography to learn physical examination skills, but not anatomy

Ultrasonography is increasingly used for teaching anatomy and physical examination skills but its effect on cognitive load is unknown. This study aimed to determine ultrasounds perceived utility for learning, and to investigate the effect of cognitive load on its perceived utility. Consenting first‐year medical students (n = 137) completed ultrasound training that includes a didactic component and four ultrasound‐guided anatomy and physical examination teaching sessions. Learners then completed a survey on comfort with physical examination techniques (three items; alpha = 0.77), perceived utility of ultrasound in learning (two items; alpha = 0.89), and cognitive load on ultrasound use [measured with a validated nine‐point scale (10 items; alpha = 0.88)]. Learners found ultrasound useful for learning for both anatomy and physical examination (mean 4.2 ± 0.9 and 4.4 ± 0.8, respectively; where 1 = very useless and 5 = very useful). Principal components analysis on the cognitive load survey revealed two factors, “image interpretation” and “basic knobology,” which accounted for 60.3% of total variance. Weighted factor scores were not associated with perceived utility in learning anatomy (beta = 0.01, P = 0.62 for “image interpretation” and beta = −0.04, P = 0.33 for “basic knobology”). However, factor score on “knobology” was inversely associated with perceived utility for learning physical examination (beta = −0.06; P = 0.03). While a basic introduction to ultrasound may suffice for teaching anatomy, more training may be required for teaching physical examination. Prior to teaching physical examination skills with ultrasonography, we recommend ensuring that learners have sufficient knobology skills. Anat Sci Educ 8: 197–204.

Reduction in Pseudomonas aeruginosa sputum density during a cystic fibrosis pulmonary exacerbation does not predict clinical response

BackgroundPulmonary exacerbations (PEx) are critical events in cystic fibrosis (CF), responsible for reduced quality of life and permanent loss of lung function. Approximately 1/4 of PEx are associated with failure to recover lung function and/or resolve symptoms. Developing tools to optimize PEx treatment is of paramount importance.MethodsWe retrospectively audited all adults infected with Pseudomonas aeruginosa, experiencing PEx necessitating parenteral antibiotic therapy from 2006–2012 from our center. Quantitative analysis of sputum at admission, twice-weekly during hospitalization, and end of therapy were compared to baseline (most recent healthy) and follow-up (after PEx) samples. Change in P. aeruginosa burden from baseline was assessed for any and all morphotypes (ALL), as well as mucoid (MUC) and non-mucoid (NON) isolates specifically. PEx were identified as failures if >90% of baseline pulmonary function was not recovered.ResultsForty-six patients meeting the above inclusion and exclusion criteria experienced 144 PEx during this time (median 3, IQR 2–6). Patients were treated for a median 14 days (IQR 13–16). No increase in ALL, MUC or NON were detected at PEx, nor was there an association between change in sputum density and magnitude of lung function decline. PEx failures were observed in 30% of events. Reductions of at least 1-log and 2 log P. aeruginosa sputum density was observed in 57% and 46% (ALL), 73% and 55% (MUC) and 58% and 46% (NON) of PEx, respectively. Factors associated with greater reduction of P. aeruginosa sputum density included choice of β-lactam antibiotic, antibiotics with in vitro predicted activity and treatment duration. PEx associated with reductions in P. aeruginosa sputum density were not associated with a reduced risk of PEx failure.ConclusionsEnhanced killing of P. aeruginosa during PEx does not predict improved clinical outcomes. Studies accounting for the polymicrobial nature of CF respiratory disease and the heterogeneity of P. aeruginosa causing chronic infection may enable the identification of a more appropriate pathogen(s) based biomarker of PEx outcomes.

Optimizing the Moisture Management Tightrope with Wound Bed Preparation 2015

PURPOSE To provide an overview of moisture management and its importance in wound care. TARGET AUDIENCE This continuing education activity is intended for physicians and nurses with an interest in skin and wound care. OBJECTIVES After participating in this educational activity, the participant should be better able to:1. Summarize causes and treatments for moisture balance issues of chronic wounds.2. Recognize the properties of dressings used for treatment for moisture management of chronic wounds and antiseptic agent cytotoxicity.3. Explain study findings of the effectiveness of dressing choices for treatment of chronic wounds. OBJECTIVE To provide an overview of moisture management and its importance in wound care. The authors evaluate the impact of moisture management for optimal wound care and assess current wound management strategies relating to antisepsis and moist wound healing utilizing the wound bed preparation paradigm 2015 update. The discussion distinguishes the form and function of wound care dressing classes available for optimal moisture management. CONCLUSION Moisture management for chronic wounds is best achieved with modern moist interactive dressings if the wound has the ability to heal.

Epidemic Pseudomonas aeruginosa infection in patients with cystic fibrosis is not a risk factor for poor clinical Outcomes following lung transplantation

BACKGROUND Epidemic strains of Pseudomonas aeruginosa (ePA) causing infection in cystic fibrosis (CF) have been commonly identified from clinics around the world. ePA disproportionally impacts CF patient pre-transplant outcomes manifesting in increased exacerbation frequency, worsened treatment burden and increased rate of lung function decline, and disproportionally leads to death and/or transplantation. As other CF factors such as pre-transplant infection with multi-resistant organisms, and isolation of P. aeruginosa in the post transplant graft, may impact post-transplant outcomes, we sought to determine if infection with ePA similarly adversely impact post-transplant outcomes. METHODS Between 1991-2014, 53 CF patients from our center received lung transplants. Bacterial strain typing was performed retrospectively on isolates collected prior to transplantation. Comprehensive chart reviews were performed to obtain baseline patient characteristics and post-transplant outcomes. RESULTS Of the 53 transplanted patients, 57% of patients were infected with ePA prior to transplant; the other 43% of patients had unique strains of P. aeruginosa. Mean age at transplant was 29.0years for ePA and 33.3years for unique (p=0.04). There were no differences in overall survival (HR=0.75, 95% CI 0.31-1.79), bronchiolitis obliterans syndrome (BOS) free survival (HR 1.43, 95% CI 0.54-4.84) or all other assessed outcomes including exacerbation frequency, chronic renal failure, acute cellular rejections, Aspergillus infection, airway stenosis, and post-transplant lymphoproliferative disorder. CONCLUSION Unlike pre-transplant outcomes, CF patients infected with ePA do not experience worse post-transplant outcomes than those infected with unique strains. Therefore, lung transplantation should be considered for all patients with P. aeruginosa infection and end stage lung disease, irrespective of infection with ePA.

Long-term clinical outcomes of 'Prairie Epidemic Strain' Pseudomonas aeruginosa infection in adults with cystic fibrosis.

Rationale Epidemic Pseudomonas aeruginosa (PA) plays an important role in cystic fibrosis (CF) lung disease. A novel strain, the ‘Prairie Epidemic Strain’ (PES), has been identified in up to 30% of patients in Prairie-based Canadian CF centres. Objective To determine the incidence, prevalence and long-term clinical impact of PES infection. Methods A cohort of adults with CF was followed from 1980 to 2014 where bacteria isolated from clinical encounters were prospectively collected. Strain typing was performed using pulse-field gel electrophoresis and multilocus sequence typing. Patients were divided into one of four cohorts: no PA, transient PA, chronic PA with unique strains and chronic PES. Proportional Cox hazard and linear mixed models were used to assess for CF-associated respiratory death or transplantation, and rates of %FEV1 and body mass index (BMI) decline. Results 274 patients (51.7% male) were analysed: 44––no PA, 29––transient PA, 137––unique PA, 64––PES. A total of 92 patients (33.6%) died or underwent lung transplantation (2423.0 patient-years). PES infection was associated with greater risk of respiratory death or lung transplant compared with the no PA group (aHR, 3.94 (95% CI 1.18 to 13.1); p=0.03) and unique PA group (aHR, 1.75 (95% CI 1.05 to 2.92) p=0.03). Rate of lung function decline (%FEV1 predicted) was greatest in the PES group (1.73%/year (95% CI 1.63% to 1.82%); p<0.001). BMI improved over time but at an attenuated rate in the PES group (p=0.001). Conclusions Infection with PES was associated with increased patient morbidity through three decades and manifested in an increased risk of respiratory death and/or lung transplantation.

The Evolving Cystic Fibrosis Microbiome: A Comparative Cohort Study Spanning 16 Years

&NA; Rationale: The cystic fibrosis (CF) airways are infected with a diverse polymicrobial community. Objectives: Understanding how changes in the CF microbiome have occurred over time, similar to the observed changes in the prevalence of cultured pathogens, is key in understanding the microbiomes role in disease. Methods: Drawing from a prospectively collected and maintained sputum biobank, we identified 45 patients with sputum samples collected between the ages of 18 and 21 years in three successive cohorts of adults transitioning to our CF clinic: A (1997‐2000), B (2004‐2007), and C (2010‐2013). Patient demographics, clinical status, and medications were collected from detailed chart review. Microbial communities were assessed by Ilumina MiSeq sequencing of the variable 3 (V3) region of the 16S rDNA. Results: The three cohorts were similar with respect to baseline demographics. There was a trend toward improved health and use of disease‐modifying therapies in each successive cohort. Shannon diversity increased in the most recent cohort, suggesting an increase in the diversity of organisms between cohorts. Furthermore, the proportion of samples with Pseudomonas‐dominated communities decreased over time, whereas Streptococcus increased. Although &bgr;‐diversity was associated with transition cohort, the greatest predictor of diversity remained lung function. Furthermore, core microbiome constituents were preserved across cohorts. Conclusions: Modest changes in the composition and structure of the microbiome of three successive cohorts of young adults with CF were observed, occurring in parallel with successive improvements in clinical status. Importantly, however, the core microbiome constituents were preserved across cohorts.

Development and Validation of a PCR Assay To Detect the Prairie Epidemic Strain of Pseudomonas aeruginosa from Patients with Cystic Fibrosis

ABSTRACT The monitoring of epidemic Pseudomonas aeruginosa is important for cystic fibrosis (CF) infection control. The prairie epidemic strain (PES) is common in western Canadian CF clinics. Using whole-genome sequencing, we identified a novel genomic island and developed a PCR assay for PES. Against a collection of 186 P. aeruginosa isolates, the assay had 98% sensitivity and 100% specificity.

Epidemiology and trends of cryptococcosis in the United States from 2000 to 2007: A population-based study:

Cryptococcal disease, caused by Cryptococcus neoformans and Cryptococcus gattii, is associated with significant morbidity and mortality but limited data exist on its incidence and impact. A study utilizing the Nationwide Inpatient Sample from 2000 to 2007 to examine the epidemiology and impact of cryptococcal disease in the United States was undertaken. The International Classification of Diseases 9th Version code was used to identify hospital discharges with diagnosis of Cryptococcus (117.5). Our primary outcome was the incidence rate of cryptococcal admissions. The impact of AIDS, age, and sex on hospitalization rates, mortality, and costs was assessed. The results showed that a total of 10,077 hospitalizations for cryptococcosis occurred corresponding to a weighted estimate of 49,010 cases. The median age was 43 years (interquartile range 34–54), and 26% were female. Approximately 64% of cases occurred in persons with AIDS. Although rates declined overall, age-adjusted rates were significantly higher in males with AIDS than in uninfected persons (p < 0.001). The mortality rate decreased but was greater in HIV-uninfected versus infected cohorts (12% versus 10%, p < 0.001). Conversely, hospital costs were greater in persons with AIDS (

Prevalence and Outcomes of Achromobacter Species Infections in Adults with Cystic Fibrosis: a North American Cohort Study

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