We describe an outbreak of Pseudomonas aeruginosa respiratory tract infections related to intrinsically contaminated ultrasound gel used for intraoperative transesophageal echocardiograms in cardiovascular surgery patients. This investigation led to a product safety alert by the Food and Drug Administration and the development of guidelines for appropriate use of ultrasound gel.

bThe Lyra Direct strep assay was compared to culture for its ability to detect Streptococcus group A and ␤-hemolytic groups C/G using rapid antigen-negative pharyngeal specimens (n ‫؍‬ 161). The Lyra assay correctly detected all ␤-hemolytic streptococci (group A, n ‫؍‬ 19; group C/G, n ‫؍‬ 5). In batch mode, the Lyra assay reduced intralaboratory turnaround time by 60% (18.1 h versus 45.0 h) but increased hands-on time by 96% (3 min 16 s versus 1 min 40 s per specimen). Various species of Streptococcus cause acute bacterial pharyngitis. Group A Streptococcus (GAS) (Streptococcus pyogenes) is the most common, but other ␤-hemolytic streptococci have also been implicated (1-3). These include S. equi, S. dysgalactiae, S. equisimilis, and S. zooepidemicus, and these in general are designated large-colony-forming or pyogenic Lancefield group C or G streptococci (4). The timely detection of these pathogens expedites appropriate antimicrobial therapy, thereby reducing illness duration and disease transmission, and in the case of GAS, nonsuppurative complications (i.e., rheumatic fever and glomerulonephritis). To improve turnaround time, rapid antigen tests (RATs) have largely augmented bacterial culture (the gold standard). However, the performance of commercially available RATs varies greatly depending upon the manufacturer, methodology used (i.e., optical immunoassay, immunochromatographic, or enzyme immunoassay), and the patient population (i.e., pediatric versus adult) being tested (5). Due to these limitations, nucleic acid amplification tests (NAATs) are being implemented in clinical laboratories. One such test, the Lyra Direct strep assay (Quidel, San Diego, CA), was recently approved (22 April 2014) by the U.S. Food and Drug Administration (FDA) for the qualitative detection and differentiation of GAS and pyogenic group C/G ␤-hemolytic streptococci from throat swab specimens obtained from patients with signs and symptoms of pharyngitis. However, the manufacturer's package insert (M112en v2014APR21) also states that all negative Lyra test results should be confirmed by bacterial culture and should not be used as the sole basis for treatment. To date, no peer-reviewed publications pertaining to the Lyra assay are available. As such, the goal of this study was to evaluate the performance and workflow characteristics of the Lyra assay as a replacement for the conventional "backup" culture in the setting of an initial negative rapid antigen test result. This study was approved by the Human Investigative Committee/Internal Review Board of Beaumont Health, MI (no. 2015-171).This evaluation included 161 unique and randomly selected outpatient subjects (pediatric [n ϭ 149; mean age, 6.3 years; age range, 0.5 to 17 years] and adult [n ϭ 12; mean age, 35.7 years; age range, 18 to 93 years]) with clinical findings supportive of acute bacterial pharyngitis. Specimens were collected with a flocked swab (ESwab) and placed into 1.0 ml of liquid Amies transport medium (Copan Diagnostics, Murrieta, CA). All specimens were negativ...