Stephen J. Cavalieri

Comparative evaluation of the E test for susceptibility testing of Nocardia species

The E Test (PDM Epsilometer; AB Biodisk, Solna, Sweden) was compared with microbroth dilution and disk diffusion for antimicrobial susceptibility testing of Nocardia as a collaborative study by two geographically separate laboratories. A total of 52 clinical isolates and five species of Nocardia were used in this comparative evaluation. Susceptibility testing was performed with Mueller-Hinton media and eight antimicrobial agents. Growth of the test strains with Mueller-Hinton medium was generally satisfactory, with the majority of isolates producing adequate growth within 24-36 h. Growth inhibition ellipses were generally well delineated and uniform for most drugs, and the points of intersection with the E Test strip were generally easy to determine. An inoculum size of approximately 2.0 x 10(7) CFU/ml was optimal for performance of the E Test method with the Nocardiae. Comparison of E Test and microbroth dilution MICs revealed 89.4% agreement for all drugs within +/- 1 log2 dilution. Using NCCLS interpretive criteria for susceptible and resistant results, complete agreement between E Test and disk diffusion results was 93.3%, and between E Test and microbroth dilution results was 96.2%. Interpretive category errors occurred at rates of 18.2% (risk corrected), 0, and 4.1% for very major, major, and minor errors, respectively, when E Test results were compared with disk diffusion results, and 0, 0, and 3.8%, respectively, when E Test was compared with microbroth dilution. Inter- and intra-laboratory reproducibility, within +/- 1 log2 dilution for all drugs, was 95% and 98%, respectively. Results from this study suggest that E Test may be suited for use as an alternative method for antimicrobial susceptibility testing of Nocardia species.

Surveillance of Community-Based Reservoirs Reveals the Presence of CTX-M, Imported AmpC, and OXA-30 β-Lactamases in Urine Isolates of Klebsiella pneumoniae and Escherichia coli in a U.S. Community

ABSTRACT β-Lactamases produced by urine isolates from patients in long-term care facilities (LTCFs), outpatient, clinics, and one hospital in a U.S. community were characterized. A total of 1.3% of all Escherichia coli and Klebsiella pneumoniae isolates collected from patients in 30 LTCFs and various outpatient clinics produced extended-spectrum β-lactamases (ESBLs) and/or imported AmpC β-lactamases.

Does Antibiotic De-escalation for Nosocomial Pneumonia Impact Intensive Care Unit Length of Stay?

BackgroundHospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), and health care–associated pneumonia (HCAP) are associated with substantial morbidity, mortality, and costs in the intensive care unit (ICU). The impact of antibiotic de-escalation on resource utilization, namely, length of stay (LOS) and cost of hospitalization, was investigated. MethodsA retrospective chart review was conducted from ICU admission of adult patients with a presumptive diagnosis of HAP, VAP, or HCAP in the 2009–2010 year. American Thoracic Society/Infectious Disease Society of America definitions for HAP, VAP, or HCAP were used. Eligible patients had blood and/or respiratory cultures collected before institution of empiric antibiotics. De-escalation required discontinuation of one or more empiric agent or change to narrower-spectrum antibiotic. The primary end point was the effect of antibiotic de-escalation on ICU LOS. ResultsOne hundred thirteen patients, representing 117 cases of HCAP, HAP, and VAP, met eligibility criteria. De-escalation was performed in 73 (62%) of pneumonias. De-escalated patients were more likely to be older (65.1 [SD, 16.8] vs 57.6 [SD, 19] years, P < 0.05) and have cardiovascular disease (37% vs 14%, P < 0.01). Intensive care unit LOS (9.3 [SD, 11.6] vs 13 [SD, 9.7] days, P = 0.069) was not significantly different; however, a significant difference in hospitalization costs (

Lemierre-Like Syndrome: A Series of Unique Cases

38,016 [SD, 43,010] vs

Whole genome mapping of the first reported case of KPC-2–positive Klebsiella pneumoniae ST258 in Nebraska

55,217 [SD, 47,642], P < 0.05) was found between the 2 groups. In-hospital mortality was significantly lower in de-escalated pneumonias (15% vs 39%, P < 0.01). ConclusionsAlthough ICU LOS was not significantly different in this study, de-escalation was associated with significant reduction in resource utilization. In ICU patients with HCAP, HAP, or VAP, de-escalation affords an opportunity to improve antimicrobial stewardship and decrease resource utilization at no detriment to clinical outcome.

Evaluation of Staphylococcus aureus Bacteremia: Academic and Community-Based Management Within the Same Health System

A previously healthy 17-year-old white girl initially presented to a local urgent care with 2 days of headache, sore throat, and fever of 104°F. Rapid Group A Streptococcus testing on a pharyngeal swab was negative, and her complete blood count (CBC) revealed a white blood cell count (WBC) of 18 300 mm-3, with 91% neutrophils. Hemoglobin (Hgb) was 14 g/dL, hematocrit 41%, and platelet count 194 000 mm-3. She was diagnosed with a viral illness and discharged home with supportive therapy. Her fever and sore throat persisted, and on day 5 of illness, she developed pain in her left chest and right hip. An urgent care facility practitioner prescribed supportive care. Over the next few days her chest and hip pain increased, and she could not bear weight on her right leg. On the eighth day of illness, she presented to a community hospital emergency room with significant pain in her hip and chest and hypovolemic shock. She had a marked leukocytosis of 40 000 mm-3, with 50% neutrophils, 32% bands, 4% lymphocytes, 1% eosinophils, 1% monocytes, 9% metamyelocytes, and 3% myelocytes. In addition, there was evidence of disseminated intravascular coagulation and elevated blood urea nitrogen, creatinine, and pancreatic and hepatic enzymes. After aggressive fluid resuscitation and hospitalization, her empirical therapy included IV vancomycin, clindamycin, and ceftriaxone. A chest CT scan revealed a large left-sided empyema with multiple septic emboli and nodularity of the thymus. Because of a concern for possible malignancy, she underwent diagnostic thoracocentesis and bone marrow aspiration. CT scan of her lower extremity confirmed a diagnosis of necrotizing fasciitis. She underwent extensive debridement of her right buttock, flank, and thigh (Figure 1). Her blood, wound, and pleural fluid cultures grew Fusobacterium necrophorum and Peptostreptococcus. She was empirically started on low-molecular-weight heparin, although there was no evidence of thrombosis. Postoperatively, she developed acute respiratory distress syndrome, required multiple chest tubes to drain pleural effusion, and multiple blood products. Her lowerextremity wound required repeated surgical debridement and vacuum-assisted wound closure. She remained in hospital for 7 weeks during which her parenteral therapy included 3 weeks of vancomycin, 6 weeks of clindamycin, 10 days of penicillin, and 2 weeks of liposomal amphotericin B for catheter-related

Use of 16s rRNA Gene Sequencing to Identify a Case of Pediococcus parvulus Bacteremia in a Patient with Metastatic Testicular Cancer

Three ertapenem-resistant Klebsiella pneumoniae carrying bla(KPC-2) were isolated from a single patient in Nebraska over a span of 5 months. A comparative analysis of the genetic relatedness of these isolates was investigated using pulsed-field gel electrophoresis, multilocus sequence typing, and whole genome mapping.

Evaluation of Etest for Susceptibility Testing of Rapidly Growing Mycobacteria

A nonrandomized, retrospective comparison of Staphylococcus aureus bacteremia between an academic hospital setting (n=53) and a community hospital setting (n=245) within a single healthcare system was performed. Despite infectious disease consultations, S. aureus bacteremia management recommendations based on Infectious Diseases Society of America (IDSA) guidelines were not followed as closely in the community hospital setting. The community hospital setting requires management standardization for patients with S. aureus bacteremia. Infect Control Hosp Epidemiol 2017;38:740-742.

Novel method for rapid identification of Nocardia species by detection of preformed enzymes.

We describe the first case of a human Pediococcus parvulus ( P. parvulus) infection, involving bacteremia in a patient with metastatic testicular cancer. Since routine phenotypic bacterial identification systems do not include this organism in their databases, and 16S rRNA gene sequencing was successfully used for its identification. Early identification of P. parvulus as the cause of an infection is critical due to its intrinsic resistance to vancomycin.