Recent epidemiological evidence suggests that genotypic and phenotypic characteristics that have typically distinguished community-associated methicillin-resistant Staphylococcus aureus (MRSA) and healthcare-associated MRSA strains may be evolving. The objective of this study was to examine the association between reduced vancomycin susceptibility (RVS) and staphylococcal cassette chromosome mec (SCCmec) type in MRSA bloodstream isolates.
A cohort study of patients who were hospitalized from 2007 to 2009 with S. aureus bacteraemia was conducted within a university health system. Bivariable analyses were conducted to determine the association between RVS and SCCmec type, as well as other microbiological characteristics including Panton–Valentine leucocidin, accessory gene regulator (agr) dysfunction and vancomycin heteroresistance.
A total of 188 patients with MRSA bacteraemia were identified: 116 (61.7%) and 72 (38.3%) patients had infections due to healthcare-associated MRSA and community-associated MRSA, respectively. As defined by a vancomycin Etest MIC > 1.0 mg/L, the prevalence of RVS was 40.4%. Isolates with RVS were significantly more likely to be associated with SCCmec II compared with isolates without RVS (74.7% and 47.3%, respectively, P < 0.001), but not with Panton–Valentine leucocidin (P = 0.10), agr dysfunction (P = 0.19) or healthcare-associated infection (P = 0.36).
The results of our study demonstrate important microbiological characteristics among MRSA isolates characterized by RVS, including a significant association between SCCmec II and elevated vancomycin MIC. It is clear that the clinical and molecular epidemiology of MRSA is evolving, and further understanding of factors determining virulence will be important for the elucidation of optimal treatment approaches for associated infections.
MRSA; virulence factors; antimicrobial resistance; epidemiology
(See the commentary by Moro, on pages 978–980.)
Infection surveillance definitions for long-term care facilities (ie, the McGeer Criteria) have not been updated since 1991. An expert consensus panel modified these definitions on the basis of a structured review of the literature. Significant changes were made to the criteria defining urinary tract and respiratory tract infections. New definitions were added for norovirus gastroenteritis and Clostridum difficile infections.
This retrospective cohort study of 39 US hospitals found that Centers for Medicare & Medicaid Services nonpayment for hospital-acquired catheter-associated urinary tract infections (UTIs) has not led to overtesting for UTI on admission or to increased antimicrobial prescribing.
Background. On 1 October 2008, in an effort to stimulate efforts to prevent catheter-associated urinary tract infection (CAUTI), the Centers for Medicare & Medicaid Services (CMS) implemented a policy of not reimbursing hospitals for hospital-acquired CAUTI. Since any urinary tract infection present on admission would not fall under this initiative, concerns have been raised that the policy may encourage more testing for and treatment of asymptomatic bacteriuria.
Methods. We conducted a retrospective multicenter cohort study with time series analysis of all adults admitted to the hospital 16 months before and 16 months after policy implementation among participating Society for Healthcare Epidemiology of America Research Network hospitals. Our outcomes were frequency of urine culture on admission and antimicrobial use.
Results. A total of 39 hospitals from 22 states submitted data on 2 362 742 admissions. In 35 hospitals affected by the CMS policy, the median frequency of urine culture performance did not change after CMS policy implementation (19.2% during the prepolicy period vs 19.3% during the postpolicy period). The rate of change in urine culture performance increased minimally during the prepolicy period (0.5% per month) and decreased slightly during the postpolicy period (–0.25% per month; P < .001). In the subset of 10 hospitals providing antimicrobial use data, the median frequency of fluoroquinolone antimicrobial use did not change substantially (14.6% during the prepolicy period vs 14.0% during the postpolicy period). The rate of change in fluoroquinolone use increased during the prepolicy period (1.26% per month) and decreased during the postpolicy period (–0.60% per month; P < .001).
Conclusions. We found no evidence that CMS nonpayment policy resulted in overtesting to screen for and document a diagnosis of urinary tract infection as present on admission.
We assessed the impact of free on-site influenza vaccination on childcare staff vaccination prevalence using 2 before-and-after studies. Vaccination was offered during the 2003–2004 and 2006–2007 influenza seasons. Staff vaccination prevalence was higher in each intervention season compared to the prior, nonintervention season. No baseline characteristics were associated with receipt of vaccination.
Colonization by methicillin-resistant Staphylococcus aureus (MRSA) may be persistent in people, and is horizontally transmissible. The scientific literature suggests that domestic pets may also participate in cross-transmission of MRSA within households. The objectives of this study were to evaluate the prevalence of and risk factors for MRSA carriage by pets residing in households with an MRSA-infected person. From 66 households in which an MRSA infected patient resided, we screened 47 dogs and 52 cats using a swab protocol. Isolates from pets and humans were genotyped using two techniques, and compared for concordance. Human participants completed a 22-question survey of demographic and epidemiologic data relevant to staphylococcal transmission. Eleven of 99 pets (11.5%) representing 9 (13.6%) of households were MRSA-positive, but in only 6 of these households were the human and animal-source strains genetically concordant. Human infection by strain USA 100 was significantly associated with pet carriage [OR = 11.4 (95% C.I. 1.7, 76.9); p=0.013]. Yet, for each day of delay in sampling the pet after the person’s MRSA diagnosis, the odds of isolating any type of MRSA from the pet decreased by 13.9% [(95% C.I. 2.6%, 23.8%); p=0.017)]. It may be concluded that pets can harbor pandemic strains of MRSA while residing in a household with an infected person. However, the source of MRSA to the pet cannot always be attributed to the human patient. Moreover, the rapid attrition of the odds of obtaining a positive culture from pets over time suggests that MRSA carriage may be fleeting.
Pets; Staphylococcus; MRSA; zoonosis; Bacterial Typing Techniques
There has been a significant increase in the prevalence of Enterobacteriaceae that produce CTX-M-type extended-spectrum β-lactamases. The objective of this study was to evaluate risk factors for infection or colonization with CTX-M-positive Escherichia coli. A case-control study was conducted within a university system from 1 January 2007 to 31 December 2008. All patients with clinical cultures with E. coli demonstrating resistance to extended-spectrum cephalosporins were included. Case patients were designated as those with cultures positive for CTX-M-positive E. coli, and control patients were designated as those with non-CTX-M-producing E. coli. Multivariable logistic regression analyses were performed to evaluate risk factors for CTX-M-positive isolates. A total of 83 (56.8%) of a total of 146 patients had cultures with CTX-M-positive E. coli. On multivariable analyses, there was a significant association between infection or colonization with CTX-M-type β-lactamase-positive E. coli and receipt of piperacillin-tazobactam in the 30 days prior to the culture date (odds ratio [OR], 7.36; 95% confidence interval [CI], 1.61 to 33.8; P = 0.01) and a urinary culture source (OR, 0.36; 95% CI, 0.17 to 0.77; P = 0.008). The rates of resistance to fluoroquinolones were significantly higher in isolates from case patients than in isolates from control patients (90.4 and 50.8%, respectively; P < 0.001). We found that nonurinary sources of clinical cultures and the recent use of piperacillin-tazobactam conferred an increased risk of colonization or infection with CTX-M-positive E. coli. Future studies will need to focus on outcomes associated with infections due to CTX-M-positive E. coli, as well as infection control strategies to limit the spread of these increasingly common organisms.
Reduced vancomycin susceptibility (RVS) may lead to poor clinical outcomes in Staphylococcus aureus bacteremia. The objective of this study was to evaluate the clinical and economic impact of RVS in patients with bacteremia due to S. aureus. A cohort study of patients who were hospitalized from December 2007 to May 2009 with S. aureus bacteremia was conducted within a university health system. Multivariable logistic regression and zero-truncated negative binomial regression models were developed to evaluate the association of RVS with 30-day in-hospital mortality, length of stay, and hospital charges. One hundred thirty-four (34.2%) of a total of 392 patients had bacteremia due to S. aureus with RVS as defined by a vancomycin Etest MIC of >1.0 μg/ml. Adjusted risk factors for 30-day in-hospital mortality included the all patient refined-diagnosis related group (APRDRG) risk-of-mortality score (odds ratio [OR], 7.11; 95% confidence interval [CI], 3.04 to 16.6), neutropenia (OR, 13.4; 95% CI, 2.46 to 73.1), white blood cell count (OR, 1.05; 95% CI, 1.01 to 1.09), immunosuppression (OR, 6.31; 95% CI, 1.74 to 22.9), and intensive care unit location (OR, 3.51; 95% CI, 1.65 to 7.49). In multivariable analyses, RVS was significantly associated with increased mortality in patients with S. aureus bacteremia as a result of methicillin-susceptible (OR, 3.90; 95% CI, 1.07 to 14.2) but not methicillin-resistant (OR, 0.53; 95% CI, 0.19 to 1.46) isolates. RVS was associated with greater 30-day in-hospital mortality in patients with bacteremia due to methicillin-susceptible S. aureus but not methicillin-resistant S. aureus. Further research is needed to identify optimal treatment strategies to reduce mortality associated with RVS in S. aureus bacteremia.
We describe the prevalence of and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-EB) in the long-term care facility (LTCF) setting. Colonization prevalence differed significantly across the 3 LTCFs evaluated in the study, with recent use of levofloxacin and fecal incontinence demonstrating borderline significant associations with ESBL-EB colonization.
Background and Purpose
The Pediatric National Institutes of Health Stroke Scale (PedNIHSS), an adaptation of the adult NIH Stroke Scale, is a quantitative measure of stroke severity shown to be reliable when scored prospectively. The ability to calculate the PedNIHSS score retrospectively would be invaluable in the conduct of observational pediatric stroke studies. The study objective was to assess the concurrent validity and reliability of estimating the PedNIHSS score retrospectively from medical records.
Neurological examinations from medical records of 75 children enrolled in a prospective PedNIHSS validation study were photocopied. Four neurologists of varying training levels blinded to the prospective PedNIHSS scores reviewed the records and retrospectively assigned PedNIHSS scores. Retrospective scores were compared among raters and to the prospective scores.
Total retrospective PedNIHSS scores correlated highly with total prospective scores (R2=0.76). Interrater reliability for the total scores was “excellent” (intraclass correlation coefficient of 0.95, 95% confidence interval 0.94–0.97). Interrater reliability for individual test items was “substantial” or “excellent” for 14 of 15 items.
The PedNIHSS score can be scored retrospectively from medical records with a high degree of concurrent validity and reliability. This tool can be used to improve the quality of retrospective pediatric stroke studies.
arterial ischemic stroke; pediatric; NIH stroke scale
Concern has been raised over the practice of unnecessary double anaerobic coverage therapy (DACT) in the hospital setting. However, the incidence of and risk factors for unnecessary DACT are not well studied. On 8 September 2008, the antimicrobial stewardship programme (ASP) at our institution was modified such that several antibiotics, including ampicillin/sulbactam and metronidazole, no longer required pre-approval. We anticipated that this change would increase both unnecessary DACT and target antibiotic consumption.
A nested case–control study was conducted to determine the cumulative incidence of and risk factors for unnecessary DACT. Cases were subjects who received unnecessary DACT while controls were subjects who did not receive DACT or who received necessary DACT. Segmented regression analysis was subsequently performed to evaluate the impact of ASP changes on unnecessary DACT and consumption of target antibiotics.
From October 2007 to September 2009, the cumulative incidence of unnecessary DACT was 2.3% [95% confidence interval (CI) 1.7–3.1]. Independent risk factors for unnecessary DACT [adjusted odds ratio (95% CI); P value] included hospitalization on a surgical ward [3.51 (1.03–12.02); P = 0.002], hospitalization on an obstetrics and gynaecology ward [9.07 (2.54–32.40); P = 0.002] and underlying metastatic malignancy [3.18 (1.38–7.09); P = 0.006]. The ASP change was associated with an increase in ampicillin/sulbactam and metronidazole consumption. However, there was no significant impact on unnecessary DACT prescribing.
Although uncommon, unnecessary DACT is more prevalent in specific services. Future qualitative studies focusing on these specific subgroups would be useful in elucidating this problem more clearly. The ASP changes were not associated with increases in unnecessary DACT.
ampicillin/sulbactam; metronidazole; antibiotic stewardship programme
Transplant centers are reluctant to perform heart transplantation in patients with hepatitis C virus (HCV) infection because augmented immunosuppression could potentially increase mortality. However, there have been few studies examining whether HCV infection reduces survival after heart transplantation.
We used data from the the U.S. Scientific Registry of Transplant Recipients to perform a multicenter cohort study evaluating the association between recipient pre-transplant HCV status and survival after heart transplantation. Adults undergoing heart transplantation between January 1, 1993 and December 31, 2007 were eligible to participate.
Among 20,687 heart transplant recipients (443 HCV-positive and 20,244 HCV-negative) at 103 institutions followed for a mean of 5.6 years, mortality was higher among HCV-positive than HCV-negative recipients (177 [40%] vs 6,367 [31.5%]; p = 0.0001). After matching on propensity score, hospital and gender, the hazard ratio (HR) of death for HCV-positive heart transplant recipients was 1.32 (95% confidence interval [CI] 1.08 to 1.61). Mortality rates were higher among HCV-positive heart transplant recipients at 1 year (9.4% vs 8.2%), 5 years (26.3% vs 22.9%), 10 years (53.1% vs 43.4%) and 15 years (74.8% vs 62.3%) post-transplantation. HRs did not vary by gender or overall number of heart transplantations performed at the center.
Pre-transplant HCV positivity is associated with decreased survival after heart transplantation.
heart transplantation; HCV; survival; mortality; outcome; cohort study
Data from a case-control study were used to derive and internally validate a prediction rule for identifying fluoroquinolone resistance in healthcare-acquired gram-negative urinary tract infection. This prediction rule has an excellent sensitivity and specificity (C-statistic, 0.816). External validation is necessary before implementing this rule to optimize empirical antibiotic use in clinical practice.
To determine the frequency of Staphylococcus aureus colonization among patients with acne and to compare the susceptibility patterns between the patients who are using antibiotics and those who are not using antibiotics.
Survey (cross-sectional) study of patients treated for acne.
Dermatology outpatient office practice
The study included 83 patients who were undergoing treatment and evaluation for acne.
Main Outcome Measure
Colonization of the nose or throat with S aureus.
A total of 36 of the 83 participants (43%) were colonized with S aureus. Two of the 36 patients (6%) had methicillin-resistant S aureus; 20 (56%) had S aureus solely in their throat; 9 (25%) had S aureus solely in their nose; and 7 (19%) had S aureus in both their nose and their throat. When patients with acne who were antibiotic users were compared with nonusers, the prevalence odds ratio for the colonization of S aureus was 0.16 (95% confidence interval [CI], 0.08–1.37) after 1 to 2 months of exposure and increased to 0.52 (95% CI, 0.12–2.17) after 2 months of exposure (P =.31). Many of the S aureus isolates were resistant to treatment with clindamycin and erythromycin (40% and 44%, respectively), particularly the nasal isolates. Very few showed resistance rates (<10%) to treatment with tetracycline antibiotics.
Unlike current dogma about the long-term use of antimicrobial agents, the prolonged use of tetracycline antibiotics commonly used to treat acne lowered the prevalence of colonization by S aureus and did not increase resistance to the tetracycline antibiotics.
We conducted population-based surveillance for pneumococcal bacteremia within a 5-county region surrounding Philadelphia from October 2001 through September 2008, the period following introduction of the seven-valent pneumococcal conjugate vaccine. Erythromycin resistance increased from 14.7% in 2001-2002 to 20.3% in 2007-2008, while the resistance rate to penicillin (MIC, ≥2 μg/ml) decreased from 7.2% to 4.2% during the same period. The most predominant serotypes associated with erythromycin resistance in 2007-2008 included 19A (29.7%), 15A (29.2%), 6C (10.1%), 3 (5.6%), and 6A (4.5%). The molecular mechanisms for the increasing erythromycin resistance were mainly due to the growing presence of mef(A) negative erm(B)+ and mef(A)+ erm(B)+ genotypes, which increased from 20.0% to 46.1% and from 1.8% to 19.1%, respectively, from 2001-2002 to 2007-2008. However, mef(A)-mediated erythromycin resistance decreased from 72.7% in 2001-2002 to 34.8% in 2007-2008. Serotypes related to the erm(B) gene were 15A (45.6%), 19A (20.9%), 3 (10.1%), and 6B (6.3%); serotypes related to the mef(A) gene were 6A (18.6%), 19A (15.0%), 6C (9.3%), and 14(8.4%); serotypes associated with the presence of both erm(B) and mef(A) were 19A (81.5%), 15A (7.7%), and 19F (6.2%). Pulsed-field gel electrophoresis analysis demonstrated that erythromycin-resistant isolates within the 19A serotype were genetically diverse and related to several circulating international clones. In contrast, erythromycin-resistant isolates within the 15A serotype consisted of clonally identical or closely related isolates.
In this narrative review, we found numerous reports suggesting that dogs and cats may play a role in household methicillin-resistant Staphylococcus aureus (MRSA) transmission and recurrent MRSA infection in human contacts. Future work should emphasize elucidating more clearly the prevalence of MRSA in household pets and characterize transmission dynamics of MRSA humans and pet animals.
Cats; Dogs; Household; MRSA; Pet animals; Transmission
To determine the interrater reliability of clinical examination by pediatric emergency medicine physicians for the diagnosis of skin and soft-tissue infections (SSTIs).
A cross-sectional study of patients presenting to a pediatric emergency department with SSTIs was performed. Each lesion was examined by a treating physician and a study physician (from a pool of 62 physicians) at the bedside during the emergency department visit. The primary outcome was reliability, as measured with the weighted κ statistic, for determining whether the lesion was an abscess and whether the lesion required a drainage procedure.
A total of 371 lesions were analyzed for interrater reliability. The weighted κ value for diagnosis of the lesion as an abscess was 0.39 (95% confidence interval: 0.32–0.47), and that for assessment of the need for drainage was 0.43 (95% confidence interval: 0.36–0.51). Agreement was statistically more likely for lesions in children ≥4 years of age but was not more likely for lesions in nonblack patients, lesions in patients with a history of or exposure to a close contact with a SSTI, or lesions examined by 2 experienced pediatric emergency medicine physicians.
Among the 62 participating physicians at our site, the reliability of the clinical examination was poor. This may indicate that improved education and/or more-objective means for diagnosing these infections in the acute care setting are warranted. Additional studies are needed to determine whether these results are generalizable to other settings.
skin and soft-tissue infections; reliability
There are limited data comparing the clinical presentations, comorbidities, and outcomes of patients with infections due to seasonal influenza with patients with infections due to pandemic (H1N1) 2009 influenza.
To compare the epidemiological characteristics and outcomes of pandemic (H1N1) 2009 influenza with those of seasonal influenza.
A cross-sectional study was conducted among patients who received diagnoses during emergency department and inpatient encounters at 2 affiliated academic medical centers in Philadelphia, Pennsylvania. Cases of seasonal influenza during the period November 1, 2005, through June 1, 2008, and cases of pandemic influenza during the period from May 1, 2009, through August 7, 2009, were identified retrospectively.
Forty-nine cases of pandemic influenza and 503 cases of seasonal influenza were identified. Patients with pandemic H1N1 were younger (median age, 29 years) than patients with seasonal influenza (median age, 59 years) (P < .001). More patients with pandemic H1N1 (35 [71%] of 49) were African American, compared with patients with seasonal influenza (267 [53%] of 503; P =.02). Several symptoms were more common among patients with pandemic influenza infections than among patients with seasonal influenza infections: cough (98% vs 83%; P =.007), myalgias (71% vs 46%; P =.001), and pleuritic chest pain (45% vs 15%; P < .001). Pregnancy was the only comorbidity that occurred significantly more often in the pandemic influenza group than in the seasonal influenza group (16% vs 1%; P < .001). There were no significant differences in frequencies of deaths of hospitalized patients, intensive care unit admission, or length of hospitalization between groups.
Other than pregnancy, there were few clinically important differences between infections due to seasonal influenza and those due to pandemic influenza. The greater rate of lower respiratory tract symptoms in pandemic cases might serve to differentiate pandemic influenza from seasonal influenza.
The impact of reduced fluconazole susceptibility on clinical and economic outcomes in patients with Candida glabrata bloodstream infections (BSI) is unknown.
A retrospective cohort study was conducted to evaluate 30-day inpatient mortality and postculture hospital charges in patients with C glabrata BSI with decreased fluconazole susceptibility (minimum inhibitory concentration [MIC] ≥ 16 μg/mL) versus fluconazole-susceptible C glabrata BSI (MIC ≤ 8 μg/mL). These analyses were adjusted for demographics, comorbidities, and time at risk. Secondary analyses limited the C glabrata group with decreased fluconazole susceptibility to MIC ≥ 64 μg/mL.
There were 45 (31%) deaths among 144 enrolled patients: 19 deaths (25%) among 76 patients with C glabrata BSI with decreased fluconazole susceptibility and 26 deaths (38%) among 68 patients with fluconazole-susceptible C glabrata BSI. Decreased fluconazole susceptibility was not independently associated with increased 30-day inpatient mortality (adjusted odds ratio, .60; 95% confidence interval (CI): .26-1.35; P = 0.22) or hospital charges (multiplicative change in hospital charges, .93; 95% CI: .60-1.43; P = 0.73). Older age was associated with increased mortality and increased time at risk was associated with increased hospital charges.
Crude mortality rates remain high in patients with C glabrata BSI. However, decreased fluconazole susceptibility was not associated with increased mortality or hospital charges.
Candida glabrata; bloodstream infections; mortality; hospital charges
Because extensive antibiotic use by inpatients has been associated with the development of multidrug-resistant organisms, we aimed to determine which variables were associated with the use of antibiotics after viral respiratory tract infection diagnosis among adult patients admitted to the hospital with respiratory symptoms.
A retrospective cohort study was conducted at 2 affiliated urban hospitals in Pennsylvania. We identified all adult patients admitted to the hospital during the period from November 1, 2005, through August 1, 2007, with a viral assay positive for influenza A or B, parainfluenza, adenovirus, or respiratory syncytial virus. Among these patients, we identified those who received antibiotics after the diagnosis of viral RTI. Data on demographics; comorbidities; and physical examination, laboratory, and radiographic findings were ascertained to identify risk factors for antimicrobial use among these patients.
A total of 196 hospitalized patients with positive viral assay results were included; 125 of 131 patients administered antibiotics continued to receive them after viral RTI diagnosis. Among 52 patients with an abnormal chest radiograph, 46 continued antibiotic therapy. An abnormal chest radiograph was independently associated with continued antibiotic use (adjusted odds ratio, 4.28 [95% confidence interval, 1.71–10.77]; P = .002). However, the majority of patients (79 of 125 [63%]) who continued antibiotic therapy had normal chest imaging findings. Eight patients (6%) who continued antibiotic therapy and no patients who stopped developed C. difficile infection (95% CI, 1.5–∞; P = .05), but there was no significant difference in length of stay or mortality.
Antibiotics are commonly used to treat hospitalized patients with known acute viral RTIs. Continued use is strongly associated with abnormal radiograph findings at admission. However, the reasons for continuation of antibiotics in the treatment of the majority of patients with normal radiographs are unclear and may represent inappropriate use.
Scientific manuscripts sometimes have two or more authors explicitly designated as having “contributed equally” to the study. The prevalence and characteristics of this practice are not known. The goal of this study was to identify longitudinal trends and characteristics of the practice of explicitly giving authors equal credit in publications found in major medical journals.
We conducted electronic keyword searches looking for original research articles with equally credited authors (ECAs) published between January 1, 2000 and December 31, 2009 in the five general medicine journals with the highest impact factors (New England Journal of Medicine, Journal of the American Medical Association, Lancet, Annals of Internal Medicine, and British Medical Journal). The annual prevalence of original research articles with ECAs for each journal.
Original research articles with authors explicitly given equal credit were found in all five journals. Articles with ECAs formed a greater proportion of the total number of articles published in each journal in 2009 versus published in 2000. [NEJM: 8.6% vs. <1%; JAMA: 7.5% vs. 0%; Annals: 3.8% vs. 0%; Lancet: 3.6% vs. <1%; BMJ: 1.0% vs. 0%]. There was a statistically significant increasing trend in yearly prevalence of ECA articles for all the journals [NEJM: p<0.0001; JAMA: p<0.001; Annals: p<0.001; Lancet: p<0.001, BMJ: p=0.001]. The first two authors listed in the byline received equal credit the majority of the time but the practice was also applied to authors in nearly every position in the byline. Finally, none of the journals provided specific guidance regarding this practice in their instructions to authors.
The practice of explicitly giving authors equal credit is increasingly common in original research publications. Scientific journals should consider providing guidance for authors regarding this practice. Furthermore, the potential impact of this practice on evaluations for academic promotion should be assessed.
authorship; credit; equal; contributions; practice
Fluoroquinolones (FQs) are the most commonly prescribed antimicrobials. The epidemiology of fecal colonization with Escherichia coli demonstrating reduced susceptibility to FQs remains unclear.
Over a three year period, all patients hospitalized >3 days were approached for fecal sampling. All E. coli with reduced susceptibility to FQs (MIC ≥0.125μg/mL to levofloxacin) were identified. We characterized gyrA and parC mutations and organic solvent tolerance. Isolates were compared using pulsed field gel electrophoresis.
Of 353 subjects colonized with E. coli demonstrating reduced FQ susceptibility, 300 (85%) had ≥ 1 gyrA mutation, 161 (45.6%) had ≥ 1 parC mutation, and 171 (48.6%) demonstrated organic solvent tolerance. The mean number of total mutations (i.e., gyrA + parC) for E. coli isolates with a levofloxacin MIC ≥8 μg/ml vs. <8.0 μg/ml was 2.70 and 0.82, respectively (p<0.001). Of the 136 E. coli isolates with a levofloxacin MIC ≤8 μg/ml, 90 (66.2%) demonstrated a nalidixic acid MIC ≥16 μg/ml. There were significant differences over time in the proportion of E. coli isolates demonstrating gyrA mutation, parC mutation, and organic solvent tolerance. There was little evidence for clonal spread of isolates.
GI tract colonization with E. coli demonstrating reduced susceptibility to levofloxacin is common. Although 40% of study isolates exhibited a levofloxacin MIC <8 μg/ml (and would thus be missed by current CLSI breakpoints), nalidixic acid resistance may be a useful marker for detection of such isolates. Significant temporal changes occurred in the proportion of isolates exhibiting various resistance mechanisms.
E. coli; fluoroquinolone; colonization; genotype; phenotype
resistance; cefepime; Pseudomonas aeruginosa; risk factors; outcomes; bacteria; research
Antimicrobial Stewardship Programs (ASPs) decrease unnecessary antimicrobial use, decrease antimicrobial resistance, and improve patient outcomes. Prior approval—requiring approval before using certain antimicrobials in an ASP—depends on the accuracy of patient data communicated from the primary service.
To determine the incidence of inaccurate communication of patient data during ASP interactions, describe examples of inaccurate communications, and identify risk factors for inaccurate communication
We utilized a retrospective cohort design. Communicated patient data were evaluated for clinically important inaccuracies using the medical record as a gold standard.
A tertiary care medical center that utilizes prior approval for restricted antimicrobials
Inpatients discussed in ASP calls
39% [CI95 (95% confidence interval) 31% to 48%] of ASP calls contained an inaccuracy in at least one type of patient data (e.g., current antimicrobials); the incidence varied widely across data types. Inaccuracy examples are given to demonstrate their clinical relevance. In multivariable analysis, inaccurate communications were more common for calls from surgical services [versus non-surgical services; odds ratio (OR) 2.1, CI95 1.1–3.9] or if received by Infectious Diseases fellows (versus pharmacists; OR 2.0, CI95 1.1–3.8).
A high proportion of ASP calls for prior approval included patient data inaccuracies, which have the potential to affect antimicrobial prescribing. While risk factors were identified, these communication errors were common across ASP interactions. Inaccurate communications may compromise the utility of prior approval ASPs in optimizing antimicrobial use.
Antimicrobial Stewardship; Communication Errors; Patient Safety