Navigating the network: a narrative overview of AMR surveillance and data flow in the United States.

The antimicrobial resistance (AMR) surveillance landscape in the United States consists of a data flow that starts in the clinical setting and is maintained by a network of national and state public health laboratories. These organizations are well established, with robust methodologies to test and confirm antimicrobial susceptibility. Still, the bridge that guides the flow of data is often one directional and caught in a constant state of rush hour that can only be refined with improvements to infrastructure and automation in the data flow. Moreover, there is an absence of information in the literature explaining the processes clinical laboratories use to coalesce and share susceptibility test data for AMR surveillance, further complicated by variability in testing procedures. This knowledge gap limits our understanding of what is needed to improve and streamline data sharing from clinical to public health laboratories. Successful models of AMR surveillance display attributes like 2-way communication between clinical and public health laboratories, centralized databases, standardized data, and the use of electronic health records or data systems, highlighting areas of opportunity and improvement. This article explores the roles and processes of the organizations involved in AMR surveillance in the United States and identifies current knowledge gaps and opportunities to improve communication between them through standardization, communication, and modernization of data flow.

Risk factors for predicting extended-spectrum ß-lactamase-producing Enterobacterales (ESBLE) infections in non-urinary isolates.

Background: With increases in antimicrobial resistance, it is crucial that patients receive appropriate antimicrobial therapy in a timely manner. Advancements in rapid diagnostics offer the ability to identify resistant organisms quickly. However, this technology is not always accessible and relies on correct specimen collection. While awaiting new microbiology methods, it may be beneficial to identify risk factors associated with common types of resistance. Specifically, extended-spectrum ß-lactamase-producing Enterobacterales (ESBLE) are a rising threat globally. Objective: The primary objective of this retrospective case-control analysis was to identify factors associated with non-urinary ESBLE versus non-ESBLE infections. Design/Methods: Patient cultures were randomly selected based on type of culture (blood, bacterial, or exudate) and organism (E. coli, K. pneumoniae, or K. oxytoca) to provide a 1:1 ratio of ESBLE to non-ESBLE infections. Baseline demographics and potential risk factors (malignancy, cirrhosis, acute kidney injury (AKI), and diabetes) were collected for each patient encounter. Results: In the univariate analysis, risk factors that achieved a significant difference included cirrhosis, AKI, presence of urinary catheter, presence of center venous catheter, history of an ESBLE infection, hospital-acquired infection, and recent fluoroquinolone, cephalosporin, or beta-lactam use. The multivariate analysis showed that four factors were independently associated with an ESBLE infection: cirrhosis, urinary catheter, central venous catheter, and history of ESBLE. Having a history of an ESBLE had the highest adjusted odds ratio (aOR 12.49; 95% CI 4.71-33.15, P < .001) of the four factors. Conclusions: These results demonstrate that there may be benefit in incorporating select risk factors into clinical decision support tools to identify patients at highest risk of ESBLE infection.

Evaluation of the impact of nasal colonization with methicillin-resistant Staphylococcus aureus on left ventricular assist device infections.

In this retrospective cohort study, we evaluated the predictive value of methicillin-resistant Staphylococcus aureus (MRSA) nasal swabs for the development of MRSA infections in patients with left ventricular assist devices. In 106 patients, the MRSA nasal swab had a negative predictive value of 92.9% demonstrating a potential role in antibiotic de-escalation.

Opportunities for antibiotic stewardship in emergency department or hospitalized patients with asymptomatic bacteriuria: identifying risk factors for antibiotic treatment.

Antibiotic treatment of asymptomatic bacteriuria (ASB) is considered inappropriate and may lead to adverse events. This 2-center, retrospective cohort study including emergency department or inpatient adults identified pyuria (odds ratio, 2.43; 95% confidence interval, 1.17-5.01; P = .02) as the only independent risk factor for antibiotic treatment of ASB.

Clinical utility of negative methicillin-resistant Staphylococcus aureus (MRSA) nasal surveillance swabs in skin and skin structure infections.

BACKGROUND: Negative methicillin-resistant Staphylococcus aureus (MRSA) nasal swabs have a high negative predictive value of approximately 99% in respiratory infections. There is, however, a lack of data evaluating its use beyond respiratory infections. METHODS: We conducted a retrospective analysis to determine the clinical utility of MRSA swabs for identifying MRSA-associated skin and skin structure infections (SSSIs) and the potential effects on antimicrobial stewardship efforts. Baseline characteristics, culture data, and antibiotic data were collected to determine the difference in duration of vancomycin therapy. Positive predictive value, negative predictive value, sensitivity, and specificity were secondary outcomes. RESULTS: A total of 473 patients were included, of which 156 patients had a positive MRSA nasal swab and 317 patients had a negative swab. The median duration of vancomycin was 4 days in the positive group and 3 days in the negative group (P = .01). The positive predictive value and negative predictive value were 22.4% and 97.5%. The sensitivity and specificity were 81.4% and 71.9%. CONCLUSION: Patients with a negative MRSA nasal swab received approximately 1 day less of vancomycin, which represented a decrease in drug administered. The negative predictive value for SSSIs is promising, showing potential for the role of MRSA nasal swabs in de-escalating therapy.

Early Multicenter Experience With Imipenem-Cilastatin-Relebactam for Multidrug-Resistant Gram-Negative Infections.

A multicenter case series of 21 patients were treated with imipenem-cilastatin-relebactam. There were mixed infection sources, with pulmonary infections (11/21,52%) composing the majority. The primary pathogen was Pseudomonas aeruginosa (16/21, 76%), and 15/16 (94%) isolates were multidrug-resistant. Thirty-day survival occurred in 14/21 (67%) patients. Two patients experienced adverse effects.

Evaluation of rapid polymerase chain reaction-based organism identification of gram-positive cocci for patients with a single positive blood culture.

For patients with a single-positive blood culture growing gram-positive cocci, organism identification can provide supportive information for differentiating contamination from infection. We investigated the effect of a rapid blood culture identification panel (BCID) on vancomycin-prescribing patterns and patient outcomes for single positive blood culture (PBC) growing gram-positive cocci. Adult patients with single-positive blood culture growing gram-positive cocci with conventional organism identification (pre-BCID) were compared with organism identification by BCID (post-BCID). Antimicrobial Stewardship Program (ASP) review of PBC was performed in both study groups. Vancomycin prescribing patterns were studied. Secondary endpoints were the incidence of nephrotoxicity, length of stay (LOS), readmission rate, mortality, and hospital costs. A total of 188 patients (86 pre-BCID, 102 post-BCID) were included. Organism identification was known 21 h sooner in the post-BCID group (P < 0.001). Coagulase-negative staphylococci were the most commonly isolated organisms (73%). In patients where vancomycin was deemed unnecessary (n = 133), vancomycin use (51% pre-BCID vs 36% post-BCID; P = 0.09) and time from culture positivity to vancomycin discontinuation (1.5 vs. 1.7 days; P = 0.92) did not differ between groups. We found no differences in the development of nephrotoxicity, LOS, readmission, mortality, or hospital costs. Earlier identification of single positive blood culture growing gram-positive cocci did not significantly influence prescribing patterns of vancomycin. However, baseline antimicrobial stewardship review of single positive blood culture growing gram-positive cocci may have lessened the opportunity for detectable differences. Larger studies, accounting for the impact of ASP intervention, should be performed to determine the value of each individual component.

Assessment of Fosfomycin for Complicated or Multidrug-Resistant Urinary Tract Infections: Patient Characteristics and Outcomes.

BACKGROUND: Bacterial resistance among uropathogens is on the rise and has led to a decreased effectiveness of oral therapies. Fosfomycin tromethamine (fosfomycin) is indicated for uncomplicated urinary tract infections (UTIs) and displays in vitro activity against multidrug-resistant (MDR) isolates; however, clinical data assessing fosfomycin for the treatment of complicated or MDR UTIs are limited. METHODS: We conducted a retrospective evaluation of patients who received ≥1 dose of fosfomycin between January 2009 and September 2015 for treatment of a UTI. Patients were included if they had a positive urine culture and documented signs/symptoms of a UTI. RESULTS: Fifty-seven patients were included; 44 (77.2%) had complicated UTIs, 36 (63.2%) had MDR UTIs, and a total of 23 (40.4%) patients had a UTI that was both complicated and MDR. The majority of patients were female (66.7%) and elderly (median age, 79 years). Overall, the most common pathogens isolated were Escherichia coli (n = 28), Enterococcus spp. (n = 22), and Pseudomonas aeruginosa (n = 8). Twenty-eight patients (49.1%) were clinically evaluable; the preponderance achieved clinical success (96.4%). Fifteen out of 20 (75%) patients with repeat urine cultures had a microbiological cure. CONCLUSIONS: This retrospective study adds to the limited literature exploring alternative therapies for complicated and MDR UTIs with results providing additional evidence that fosfomycin may be an effective oral option.

Susceptibility of Multidrug-Resistant Gram-Negative Urine Isolates to Oral Antibiotics.

Increasing resistance among Gram-negative uropathogens limits treatment options, and susceptibility data for multidrug-resistant isolates are limited. We assessed the activity of five oral agents against 91 multidrug-resistant Gram-negative urine isolates that were collected from emergency department/hospitalized patients. Fosfomycin and nitrofurantoin were most active (>75% susceptibility). Susceptibilities to sulfamethoxazole-trimethoprim, ciprofloxacin, and ampicillin were ≤40%; empirical use of these agents likely provides inadequate coverage in areas with a high prevalence of multidrug-resistant uropathogens.

Activity of fosfomycin and comparison of several susceptibility testing methods against contemporary urine isolates.

Fosfomycin is recommended as first-line treatment for acute uncomplicated cystitis in women. It has demonstrated in vitro activity against a variety of pathogens; however, a paucity of data are available from the USA. We determined the susceptibility of a collection of urine isolates to fosfomycin and compared multiple methods of susceptibility testing. Consecutive non-duplicate Enterobacteriaceae, enterococci and Pseudomonas aeruginosa isolates were collected from the clinical microbiology laboratory between August 2013 and January 2014. Isolates represented hospitalised or emergency department patients with monomicrobial bacteriuria. Fosfomycin MICs were determined in duplicate, on separate days, by Etest and disk diffusion and results were compared with agar dilution. Nitrofurantoin and ciprofloxacin were used as comparators. MIC results were categorised using Clinical and Laboratory Standards Institute interpretive criteria for Escherichia coli and Enterococcus faecalis. Correlation between the three testing methods was evaluated. Overall susceptibility to fosfomycin was 94.4%, 93.5% and 87.9% by agar dilution, disk diffusion and Etest, respectively. Five fosfomycin-resistant isolates were identified, including two Morganella morganii, one P. aeruginosa, one Proteus mirabilis and one Enterobacter aerogenes. Across all organisms, rates of essential agreement, categorical agreement, minor errors, major errors and very major errors for Etest/disk diffusion compared with agar dilution were 77.3%/NA, 89.5/93.8%, 7.1/5.0%, 3.6/1.3% and 0/0%, respectively. Fosfomycin displayed fairly consistent activity against a majority of isolates collected when using the susceptibility breakpoint of 64 µg/mL. MICs for E. coli were particularly low (≤2 µg/mL). These data lend support to current guidelines that recommend fosfomycin as empirical first-line therapy for uncomplicated UTI.

Surface microbiology of the iPad tablet computer and the potential to serve as a fomite in both inpatient practice settings as well as outside of the hospital environment.

BACKGROUND: The use of tablet computers and other touch screen technology within the healthcare system has rapidly expanded. It has been reported that these devices can harbor pathogens in hospitals; however, much less is known about what pathogens they can harbor when used outside the hospital environment compared to hospital practice. METHODS: Thirty iPads belonging to faculty with a variety of practice settings were sampled to determine the presence and quantity of clinically-relevant organisms. Flocked nylon swabs and neutralizer solution were used to sample the surface of each iPad. Samples were then plated on a variety of selective agars for presence and quantity of selected pathogens. In addition, faculty members were surveyed to classify the physical location of their practice settings and usage patterns. Continuous variables were compared via an unpaired Student's t test with two-tailed distribution; categorical variables were compared with the Fisher's exact test. RESULTS: Of the iPads sampled, 16 belonged to faculty practicing within a hospital and 14 belonged to a faculty member practicing outside a hospital. More faculty within the hospital group used their iPads at their practice sites (78.6% vs. 31.3%; p = 0.014) and within patient care areas (71.4% vs. 18.8%; p = 0.009) than the non-hospital group. There were no differences in the presence, absence, or quantity of, any of the pathogens selectively isolated between groups. Problematic nosocomial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and P. aeruginosa were isolated from both hospital and non-hospital faculty iPads. CONCLUSIONS: Gram positive and Gram negative organisms were recovered from the surfaces of iPads regardless of practice setting; these included problematic multidrug-resistant pathogens like MRSA, VRE, and Pseudomonas aeruginosa. Healthcare personnel in all settings should be aware of the potential for tablet computers to serve as a nidus for microorganism transmission.