Use of the Accelerate Pheno System for Identification and Antimicrobial Susceptibility Testing of Pathogens in Positive Blood Cultures and Impact on Time to Results and Workflow.

The Accelerate Pheno system uses automated fluorescence in situ hybridization technology with morphokinetic cellular analysis to provide rapid species identification (ID) and antimicrobial susceptibility testing (AST) results for the most commonly identified organisms in bloodstream infections. The objective was to evaluate the accuracy and workflow of bacterial and yeast ID and bacterial AST using the Accelerate Pheno system in the clinical microbiology laboratory. The consecutive fresh blood cultures received in the laboratory were analyzed by the Accelerate Pheno system within 0 to 8 h of growth detection. ID/AST performance, the average times to results, and workflow were compared to those of the routine standard of care. Of the 232 blood cultures evaluated (223 monomicrobial and 9 polymicrobial) comprising 241 organisms, the overall sensitivity and specificity for the identification of organisms were 95.6% and 99.5%, respectively. For antimicrobial susceptibility, the overall essential agreement was 95.1% and categorical agreement was 95.5% compared to routine methods. There was one very major error and 3 major errors. The time to identification and the time to susceptibility using the Accelerate Pheno system were decreased by 23.47 and 41.86 h, respectively, compared to those for the standard of care. The reduction in hands on time was 25.5 min per culture. The Accelerate Pheno system provides rapid and accurate ID/AST results for most of the organisms found routinely in blood cultures. It is easy to use, reduces hands on time for ID/AST of common blood pathogens, and enables clinically actionable results to be released much earlier than with the current standard of care.

The performance of Luminex ARIES® Flu A/B & RSV and Cepheid Xpert® Flu/RSV XC for the detection of influenza A, influenza B, and respiratory syncytial virus in prospective patient samples.

BACKGROUND: The demand for rapid, accurate viral testing has increased the number of assays available for the detection of viral pathogens. One of the newest FDA cleared platforms is the Luminex ARIES® Flu A/B & RSV, which is a fully automated, real-time PCR-based assay used for detection of influenza A, influenza B, and respiratory syncytial virus (RSV). OBJECTIVES: We sought to compare the performance of Luminex ARIES® Flu A/B & RSV assay to the Cepheid Xpert® Flu/RSV XC assay for rapid Flu and RSV testing. STUDY DESIGN: A series of consecutive nasopharyngeal specimens received in the clinical microbiology laboratory during peak influenza season at a major academic center in Chicago, IL, were prospectively tested, using both the ARIES® Flu A/B & RSV and Xpert® Flu/RSV XC assays, side by side. Discrepant results were tested on the BioFire FilmArray® Respiratory Panel for resolution. RESULTS: A total of 143 consecutive nasopharyngeal specimens, obtained from patients ranging from six months to ninety-three years in age were received between January 1st, 2017 and March 21st, 2017. There was 96.6% agreement between the two assays for detection influenza A, 100% agreement for detection influenza B and RSV, and 98.9% agreement for negative results. The Xpert® Flu/RSV XC performed with an average turn-around time of approximately 60min, compared to the ARIES® Flu A/B & RSV of approximately 120min. Both assays were equally easy to perform, with a similar amount of hands-on technologist time for each platform. CONCLUSIONS: Overall, these results indicate that both tests are comparable in terms of result agreement and technical ease-of-use. The Xpert® Flu/RSV XC assay did produce results with less turn-around-time, approximately 60min quicker than the ARIES® Flu A/B & RSV.

Comparison of Cepheid Xpert Flu/RSV XC and BioFire FilmArray for Detection of Influenza A, Influenza B, and Respiratory Syncytial Virus.

The Xpert Flu/RSV XC was compared to the FilmArray respiratory panel for detection of influenza (Flu) A, Flu B, and respiratory syncytial virus (RSV), using 128 nasopharyngeal swabs. Positive agreements were 100% for Flu A and RSV and 92.3% for Flu B. The Xpert may be useful in clinical situations when extensive testing is not required and may serve an important role in laboratories already performing broader respiratory panel testing.

Prospective evaluation of the VITEK MS for the routine identification of bacteria and yeast in the clinical microbiology laboratory: assessment of accuracy of identification and turnaround time.

This study assessed the accuracy of bacterial and yeast identification using the VITEK MS, and the time to reporting of isolates before and after its implementation in routine clinical practice. Three hundred and sixty-two isolates of bacteria and yeast, consisting of a variety of clinical isolates and American Type Culture Collection strains, were tested. Results were compared with reference identifications from the VITEK 2 system and with 16S rRNA sequence analysis. The VITEK MS provided an acceptable identification to species level for 283 (78 %) isolates. Considering organisms for which genus-level identification is acceptable for routine clinical care, 315 isolates (87 %) had an acceptable identification. Six isolates (2 %) were identified incorrectly, five of which were Shigella species. Finally, the time for reporting the identifications was decreased significantly after implementation of the VITEK MS for a total mean reduction in time of 10.52 h (P<0.0001). Overall, accuracy of the VITEK MS was comparable or superior to that from the VITEK 2. The findings were also comparable to other studies examining the accuracy of the VITEK MS, although differences exist, depending on the diversity of species represented as well as on the versions of the databases used. The VITEK MS can be incorporated effectively into routine use in a clinical microbiology laboratory and future expansion of the database should provide improved accuracy for the identification of micro-organisms.

Prior antimicrobial exposure and the risk for bloodstream infection with fluconazole-non-susceptible Candida strains.

Candida species are a common cause of bloodstream infection among hospitalized patients. Increasingly these infections are caused by strains resistant to commonly used antifungal agents. The aim of this study was to assess the association between exposure to specific antimicrobial agents and subsequent bloodstream infection with fluconazole-non-susceptible and fluconazole-susceptible Candida strains. A retrospective case-case-control study was performed. From 2002 to 2006, 50 consecutive patients with hospital-acquired bloodstream infection caused by Candida strains not fully susceptible to fluconazole were identified (case group 1). For comparison, 54 patients with fluconazole-susceptible candidaemia (case group 2) and a control group of 104 patients without candidaemia were studied. Models were adjusted for demographic and clinical risk factors. The risk for candidaemia associated with exposure to specific antimicrobial agents was assessed. Piperacillin/tazobactam (odds ratio (OR) 6.8, 95% confidence interval (CI) 1.4-32.2) and ciprofloxacin (OR 8.0, 95% CI 1.5-42.5), but not fluconazole, were significant risk factors for bloodstream infection with fluconazole-non-susceptible Candida. Only ciprofloxacin (OR 7.8, 95% CI 1.2-50.7) was associated with bloodstream infection with fluconazole-susceptible Candida. Despite adjustment for prior exposure to fluconazole, exposure to specific antibacterial agents was associated with hospital-acquired bloodstream infection with fluconazole-non-susceptible Candida.

Outbreak of human adenovirus type 3 infection in a pediatric long-term care facility--Illinois, 2005.

BACKGROUND: Human adenovirus type 3 (HAdV-3) causes severe respiratory illness in children, but outbreaks in long-term care facilities have not been frequently reported. We describe an outbreak of HAdV-3 infection in a long-term care facility for children with severe neurologic impairment, where only 3 of 63 residents were ambulatory. METHODS: A clinical case of HAdV-3 was defined as fever (temperature, > or = 38.0 degrees C) and either a worsening of respiratory symptoms or conjunctivitis in a resident, with illness onset from June through August 2005. We reviewed medical records; conducted surveillance for fever, conjunctivitis, and respiratory symptoms; and collected nasopharyngeal and conjunctival specimens from symptomatic residents. Specimens were cultured in HAdV-permissive cell lines or were analyzed by HAdV-specific polymerase chain reaction assay. RESULTS: Thirty-five (56%) of 63 residents had illnesses that met the case definition; 17 patients (49%) were admitted to intensive care units, and 2 (6%) died. Patients were hospitalized in the intensive care unit for a total of 233 patient-days. Illness onset dates ranged from 1 June through 24 August 2005. Thirty-two patients (91%) had respiratory infection, and 3 (9%) had conjunctivitis. HAdV was identified by culture or PCR in 20 patients. Nine isolates were characterized as HAdV-3 genome type a2. CONCLUSIONS: Considering the limited mobility of residents and their reliance on respiratory care, transmission of HAdV-3 infection during this outbreak likely occurred through respiratory care provided by staff. In environments where patients with susceptible underlying conditions reside, HAdV infection should be considered when patients are identified with worsening respiratory disease, and rapid diagnostic tests for HAdV infection should be readily available to help identify and curtail the spread of this pathogen.

Reduction of preoperative conjunctival bacterial flora with the use of mupirocin nasal ointment.

PURPOSE: To determine whether the use of mupirocin ointment for preoperative eradication of nasal bacterial carriage was effective in reducing conjunctival bacterial flora. METHODS: Prospective, double-arm, blinded clinical trial of 37 eyes of 37 patients undergoing intraocular surgery (cataract extraction or pars plana vitrectomy) randomized to either control or mupirocin treatment groups. Treated patients received mupirocin nasal ointment twice daily for 5 days prior to surgery. Nasal cultures were obtained in all patients. All patients received a standard 5% povidone-iodine preparation before the surgical procedure, and conjunctival cultures were obtained in all patients before and after the povidone-iodine preparation. RESULTS: All 37 patient nasal swabs were positive for bacterial growth (cultures were obtained prior to the use of mupirocin ointment in the treatment group). One of 15 eyes (6.7%) in the treatment group had positive conjunctival cultures prior to povidone-iodine preparation, compared with nine of 22 eyes (41%) in the control group (P < .05). Even after povidone-iodine preparation, eight of 22 eyes (36%) in the control group demonstrated persistent positive cultures, whereas one (6.7%) of the treatment eyes exhibited growth (P < .05). CONCLUSIONS: Prophylactic use of mupirocin nasal ointment resulted in significant reduction of conjunctival flora with or without preoperative topical 5% povidone-iodine preparation. The use of mupirocin nasal ointment prior to intraocular surgery or intravitreal injections is a novel method for reducing conjunctival contamination rates, which theoretically should reduce the incidence of endophthalmitis.