Browsing by Author "Schmitt, Bryan H."
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Item 322. Evaluation of the BioFire® Bone and Joint Infection (BJI) Panel for the Detection of Microorganisms and Antimicrobial Resistance Genes in Synovial Fluid Specimens(Oxford University Press, 2020-12) Graue, Corrin; Schmitt, Bryan H.; Waggoner, Amy; Laurent, Frederic; Abad, Lelia; Bauer, Thomas; Mazariegos, Irving; Balada-Llasat, Joan-Miquel; Horn, Jarid; Wolk, Donna; Jefferis, Alexa; Hermans, Mirjam; Verhoofstad, Irma; Butler-Wu, Susan; Umali-Wilcox, Minette; Murphy, Caitlin N.; Cabrera, Barbara J.; Esteban, Jaime; Macias-Valcayo, Alicia; Craft, David; von Bredow, Benjamin; Leber, Amy; Everhart, Kathy; Dien Bard, Jennifer; Mestas, Jvier; Daly, Judy; Barr, Rebecca; Kensinger, Bart; Pons, Benedicte; Jay, Corinne; Pathology and Laboratory Medicine, School of MedicineBackground Bone and Joint Infections (BJIs) present with non-specific symptoms that may include pain, swelling, and fever and are associated with high morbidity and significant risk of mortality. BJIs can be caused by a variety of bacteria and fungi, including anaerobes and microorganisms that can be challenging to culture or identify by traditional microbiological methods. Clinicians primarily rely on culture to identify the pathogen(s) responsible for infection. The BioFire® Bone and Joint Infection (BJI) Panel (BioFire Diagnostics, Salt Lake City, UT) is designed to detect 15 gram-positive bacteria (including seven anaerobes), 14 gram-negative bacteria (including one anaerobe), two yeast, and eight antimicrobial resistance (AMR) genes from synovial fluid specimens in about an hour. The objective of this study was to evaluate the performance of an Investigational Use Only (IUO) version of the BioFire BJI Panel compared to various reference methods. Methods Remnant synovial fluid specimens, which were collected for routine clinical care at 13 study sites in the US and Europe, underwent testing using an IUO version of the BioFire BJI Panel. Performance of this test was determined by comparison to Standard of Care (SoC) consisting of bacterial culture performed at each study site according to their routine procedures. Results A total of 1544 synovial fluid specimens were collected and tested with the BioFire BJI Panel. The majority of specimens were from knee joints (77.9%) and arthrocentesis (79.4%) was the most common collection method. Compared to SoC culture, overall sensitivity was 90.2% and specificity was 99.8%. The BioFire BJI Panel yielded a total of 268 Detected results, whereas SoC yielded a total of 215 positive results for on-panel analytes. Conclusion The BioFire BJI Panel is a sensitive, specific, and robust test for rapid detection of a wide range of analytes in synovial fluid specimens. The number of microorganisms and resistance genes included in the BioFire BJI Panel, together with a reduced time-to-result and increased diagnostic yield compared to culture, is expected to aid in the timely diagnosis and appropriate management of BJIs.Item 754. Performance Characterization of a Real Time PCR Assay for Pneumocystis jirovecii in Bronchoalveolar Lavage Fluid and Sputum(Oxford University Press, 2020-10) Bell, Drew T.; Koehlinger, Jeremy; Schmitt, Bryan H.; Pathology and Laboratory Medicine, School of MedicineBackground Pneumocystis jirovecii pneumonia (PJP) affects immunocompromised patients and contributes significantly to mortality. Outcomes depend on early treatment, making timely and accurate diagnosis critical. Typically, PJP diagnosis is through identification of trophozoite or cyst forms in bronchoalveolar lavage (BAL) fluid or sputum, a labor-intensive and insensitive process. Options for more accessible and sensitive molecular detection are limited. It is known that patients may be colonized, which can cast doubt on the clinical significance of low levels of DNA amplification in qualitative result reporting. In this study, we describe a real time (rt) PCR assay utilizing analyte specific reagent primers targeting the mtLSU gene of P. jirovecii and correlate amplification with morphological PJP identification. Methods IUHPL Clinical Microbiology assessed sputum or BAL fluid from 109 patients with clinical concern for PJP microscopically via fungal stains (GMS, calcofluor white). Comparative rtPCR was conducted as follows. First, 2µL of residual specimen or control were mixed with an 8µL combination of rtPCR mastermix, control DNA, and primer pairs (Simplexa). No nucleic acid extraction was performed. Real time PCR was executed and analyzed on the LIAISON MDX (DiaSorin) platform. Qualitative amplification results and cycle threshold (CT) values were correlated with microscopic methods to establish performance. Chart review was performed to assess the clinical impact of this assay. Results P. jirovecii was microscopically detected in 26% (29/109) of samples, while 31.1% (34/109) exhibited amplification by rtPCR. Agreement between the two methods was 95.4%; rtPCR demonstrated 100% sensitivity and 93.8% specificity in comparison. Conclusion Our results indicate that this assay has exceptional negative predictive value (100%), and therefore may be valuable as a screening test. Considering this data alone, the positive predictive value is lower (85.3%). Further examination of the data, however, revealed that 80% (4/5) of discrepant results demonstrated CT values of >34, while the highest CT for a microscopically positive sample was 31.2. Further clinical correlation may establish a CT cutoff that will reduce false positive and potentially clinically insignificant cases.Item Clinical comparison and agreement of PCR, antigen, and viral culture for the diagnosis of COVID-19: Clinical Agreement Between Diagnostics for COVID19(Elsevier, 2022) Agard, Amanda; Elsheikh, Omar; Bell, Drew; Relich, Ryan F.; Schmitt, Bryan H.; Sadowski, Josh; Fadel, William; Webb, Douglas H.; Dbeibo, Lana; Kelley, Kristen; Carozza, Mariel; Lei, Guang-Shen; Calkins, Paul; Beeler, Cole; Medicine, School of MedicineThe aim of this study is to compare the COVID-19 nasopharyngeal PCR (NP PCR) to antigen, nasal PCR, and viral culture. One-hundred-and-fourteen risk-stratified patients were tested by culture, nasal PCR, NP PCR, and Ag testing. Twenty (48%) of the high risk and 23 (32%) of the low risk were NP PCR positive. Compared with NP PCR, the sensitivity of nasal PCR, Sofia Ag, BinaxNOW Ag, and culture were 44%, 31%, 37%, and 15%. In the high risk group, the sensitivity of these tests improved to 71%, 37%, 50%, and 22%. Agreement between tests was highest between nasal PCR and both antigen tests. Patients who were NP PCR positive but antigen negative were more likely to have remote prior COVID-19 infection (p<0.01). Nasal PCR and antigen positive patients were more likely to have symptoms (p = 0.01).Item Detection of the Dimorphic Phases of Mucor circinelloides in Blood Cultures from an Immunosuppressed Female.(Hindawi, 2016) Arroyo, Miguel A.; Schmitt, Bryan H.; Davis, Thomas E.; Relich, Ryan F.; Department of Pathology and Laboratory Medicine, IU School of MedicineMucormycosis fungemia is rarely documented since blood cultures are nearly always negative. We describe a case of Mucor circinelloides fungemia in a patient with a history of a sinus infection, sarcoidosis, and IgG deficiency. The identity of the isolate was supported by its microscopic morphology and its ability to convert into yeast forms under anaerobic conditions. The early detection, initiation of liposomal amphotericin B treatment, and reversal of underlying predisposing risk factors resulted in a good outcome.Item Direct antimicrobial susceptibility testing of positive blood cultures: A comparison of the accelerate Pheno™ and VITEK® 2 systems(Elsevier, 2019) Schneider, Jack G.; Wood, James B.; Smith, Nathan W.; Emery, Christopher L.; Davis, Thomas E.; Manaloor, John J.; Bocian, Brittany; Schmitt, Bryan H.; Medicine, School of MedicineObjectives To compare the performance and time-to-result (TTR) for antimicrobial susceptibility testing (AST) of positive blood cultures (PBC) using the Accelerate Pheno™ system (AXDX) and both a direct VITEK® 2 card inoculation workflow (DV2) and traditional FDA-approved VITEK® 2 workflow using subcultured isolates (V2). Methods Patient samples with monomicrobial Gram-negative rod bacteremia were tested on AXDX and DV2 in tandem, and compared to V2 AST results. Categorical agreement (CA) errors were adjudicated using broth microdilution. Instrumentation times and AST TTR were compared. Results AXDX and DV2 had a CA of 91.5% and 97.4%, respectively, compared to V2. Post-adjudication, AXDX, DV2, and V2 had CA of 94.7%, 95.7% and 96.5%, respectively. Instrument run times were 6.6 h, 9.4 h, and 9.2 h, and AST TTR were 8.9 h, 12.9 h and 35.5 h, respectively. Conclusions AXDX and DV2 AST is fast and reliable, which may have significant antimicrobial stewardship implications.Item Evaluation of T2Candida Panel for detection of Candida in peritoneal dialysates(Sage, 2019-01) Kouri, Anne M.; Kieffer, Theodore W.; Nailescu, Corina; Leiser, Jeffrey; Schmitt, Bryan H.; Relich, Ryan F.; Davis, Thomas E.; Manaloor, John J.; Pediatrics, School of MedicineFungal peritonitis in the peritoneal dialysis population is difficult to diagnose promptly due to the inherently slow cultivation-based methods currently required for identification of peritonitis pathogens. Because of the moderate risk for severe complications, the need for rapid diagnostics is considerable. One possible solution to this unmet need is the T2Candida Panel, a new technology designed to detect the most common pathogenic Candida spp. directly from whole blood specimens in as little as a few hours. We hypothesized that this technology could be applied to the detection of Candida in peritoneal dialysate, a matrix not currently approved by the Food and Drug Administration for testing by this system. Remnant dialysate samples from three healthy (noninfected) pediatric peritoneal dialysis patients were spiked with Candida glabrata, serially diluted, and tested in triplicate with unaltered dialysate specimens. The assay detected C. glabrata in 100% of spiked dialysate samples across the full spectrum of dilutions tested, and no assay inhibition or cross-reactivity was noted. These findings suggest one of possibly more applications of this technology. The positive clinical implications of this test will continue to be realized as its use is validated in peritoneal dialysate and other patient specimen types.Item Francisella philomiragia Bacteremia in a Patient with Acute Respiratory Insufficiency and Acute-on-Chronic Kidney Disease(American Society for Microbiology, 2015-12) Relich, Ryan F.; Humphries, Romney M.; Mattison, H. Reid; Miles, Jessica E.; Simpson, Edward R.; Corbett, Ian J.; Schmitt, Bryan H.; May, M.; Department of Pathology & Laboratory Medicine, IU School of MedicineFrancisella philomiragia is a very uncommon pathogen of humans. Diseases caused by it are protean and have been reported largely in near-drowning victims and those with chronic granulomatous disease. We present a case of F. philomiragia pneumonia with peripheral edema and bacteremia in a renal transplant patient and review the diverse reports of F. philomiragia infections.Item Induction of β-Lactamase Activity and Decreased β-Lactam Susceptibility by CO2 in Clinical Bacterial Isolates(American Society for Microbiology, 2017-07-19) Mullen, Nathan; Raposo, Hugo; Gudis, Polyxeni; Barker, Linsey; Humphries, Romney M.; Schmitt, Bryan H.; Relich, Ryan F.; May, Meghan; Pathology and Laboratory Medicine, School of MedicineAntimicrobial susceptibility testing of clinical isolates is a crucial step toward appropriate treatment of infectious diseases. The clinical isolate Francisella philomiragia 14IUHPL001, recently isolated from a 63-year-old woman with atypical pneumonia, featured decreased susceptibility to β-lactam antibiotics when cultivated in 5% CO2. Quantitative β-lactamase assays demonstrated a significant (P < 0.0001) increase in enzymatic activity between bacteria cultivated in 5% CO2 over those incubated in ambient air. The presence of β-lactamase genes blaTEM and blaSHV was detected in the clinical isolate F. philomiragia 14IUHPL001 by PCR, and the genes were positively identified by nucleotide sequencing. Expression of blaTEM and blaSHV was detected by reverse transcription-PCR during growth at 5% CO2 but not during growth in ambient air. A statistically significant alkaline shift was observed following cultivation of F. philomiragia 14IUHPL001 in both ambient air and 5% CO2, allowing desegregation of the previously reported effects of acidic pH from the currently reported effect of 5% CO2 on blaTEM and blaSHV β-lactamases. To ensure that the observed phenomenon was not unique to F. philomiragia, we evaluated a clinical isolate of blaTEM-carrying Haemophilus influenzae and found parallel induction of blaTEM gene expression and β-lactamase activity at 5% CO2 relative to ambient air. IMPORTANCE β-Lactamase induction and concurrent β-lactam resistance in respiratory tract pathogens as a consequence of growth in a physiologically relevant level of CO2 are of clinical significance, particularly given the ubiquity of TEM and SHV β-lactamase genes in diverse bacterial pathogens. This is the first report of β-lactamase induction by 5% CO2.Item Microbiology of bile aspirates obtained at ERCP in patients with suspected acute cholangitis(Thieme, 2022) Gromski, Mark A.; Gutta, Aditya; Lehman, Glen A.; Tong, Yan; Fogel, Evan L.; Watkins, James L.; Easler, Jeffrey J.; Bick, Benjamin L.; McHenry, Lee; Beeler, Cole; Relich, Ryan F.; Schmitt, Bryan H.; Sherman, Stuart; Medicine, School of MedicineBackground: The cornerstone of treatment for acute cholangitis is source control with biliary drainage and early antibiotics. The primary aim of this study was to describe the microbiology of bile aspirate pathogens obtained at the time of endoscopic retrograde cholangiopancreatography (ERCP) in patients suspected of having acute cholangitis. Methods: In this single-center retrospective study, patients were included if a bile aspirate was collected at ERCP for suspicion of acute cholangitis, from 1 January 2010 to 31 December 2016. Results: There were 721 ERCP procedures for suspected acute cholangitis with bile culture results, with 662 positive bile cultures (91.8 %). Pathogens included: Enterococcus species (spp.) 448 (67.7 %); Klebsiella spp. 295 (44.6 %); Escherichia coli 269 (40.6 %); Pseudomonas spp. 52 (7.9 %); and anaerobes 64 (9.7 %). Susceptibility of Klebsiella pneumoniae and E.coli isolates to ciprofloxacin was 88 % and 64 %, respectively. Extended-spectrum beta-lactamases and carbapenem resistance were found in 7.9 % and 3.6 % of Enterobacteriaceae, respectively. There were 437 concurrent blood cultures, of which 174 were positive (39.8 % of cultures drawn). Prior biliary endoscopic sphincterotomy (ES) was evident in 459 ERCP cases (63.7 %), and was associated with increased frequency of Klebsiella spp., Pseudomonas aeruginosa, Enterobacter spp., and Enterococcus spp. Prior biliary ES significantly increased the probability of vancomycin-resistant Enterococcus (VRE). Conclusions: The vast majority of bile cultures (91.8 %) were positive. The susceptibilities of E.coli and K.pneumoniae to ciprofloxacin are lower than historically noted. A notable portion of cultures contained pathogenic drug-resistant organisms. Prior biliary ES is associated with a higher frequency of certain organisms and higher frequency of VRE.Item Multicenter evaluation of the BIOFIRE Joint Infection Panel for the detection of bacteria, yeast, and AMR genes in synovial fluid samples(American Society for Microbiology, 2023) Esteban, Jaime; Salar-Vidal, Llanos; Schmitt, Bryan H.; Waggoner, Amy; Laurent, Frédéric; Abad, Lelia; Bauer, Thomas W.; Mazariegos, Irving; Balada-Llasat, Joan-Miquel; Horn, Jared; Wolk, Donna M.; Jefferis, Alexa; Hermans, Mirjam; Verhoofstad, Irma; Butler-Wu, Susan M.; Umali-Wilcox, Minette; Murphy, Caitlin; Cabrera, Barbara; Craft, David; von Bredow, Benjamin; Leber, Amy; Everhart, Kathy; Dien Bard, Jennifer; Flores, Irvin Ibarra; Daly, Judy; Barr, Rebecca; Holmberg, Kristen; Graue, Corrin; Kensinger, Bart; Medicine, School of MedicineThe bioMérieux BIOFIRE Joint Infection (JI) Panel is a multiplex in vitro diagnostic test for the simultaneous and rapid (~1 h) detection of 39 potential pathogens and antimicrobial resistance (AMR) genes directly from synovial fluid (SF) samples. Thirty-one species or groups of microorganisms are included in the kit, as well as several AMR genes. This study, performed to evaluate the BIOFIRE JI Panel for regulatory clearance, provides data from a multicenter evaluation of 1,544 prospectively collected residual SF samples with performance compared to standard-of-care (SOC) culture for organisms or polymerase chain reaction (PCR) and sequencing for AMR genes. The BIOFIRE JI Panel demonstrated a sensitivity of 90.9% or greater for all but six organisms and a positive percent agreement (PPA) of 100% for all AMR genes. The BIOFIRE JI Panel demonstrated a specificity of 98.5% or greater for detection of all organisms and a negative percent agreement (NPA) of 95.7% or greater for all AMR genes. The BIOFIRE JI Panel provides an improvement over SOC culture, with a substantially shorter time to result for both organisms and AMR genes with excellent sensitivity/PPA and specificity/NPA, and is anticipated to provide timely and actionable diagnostic information for joint infections in a variety of clinical scenarios.