Browsing by Author "Denys, Gerald A."

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    Five-Year Longitudinal Assessment (2008 to 2012) of E-101 Solution Activity against Clinical Target and Antimicrobial-Resistant Pathogens
    (American Society for Microbiology (ASM), 2014-08) Denys, Gerald A.; Pillar, Chris M.; Sahm, Daniel F.; O'Hanley, Peter; Stephens, Jackson T. Jr; Department of Pathology & Laboratory Medicine, IU School of Medicine
    This study summarizes the topical E-101 solution susceptibility testing results for 760 Gram-positive and Gram-negative target pathogens collected from 75 U.S. sites between 2008 and 2012 and 103 ESKAPE pathogens. E-101 solution maintained potent activity against all bacterial species studied for each year tested, with MICs ranging from <0.008 to 0.25 μg porcine myeloperoxidase (pMPO)/ml. These results confirm that E-101 solution retains its potent broad-spectrum activity against U.S. clinical isolates and organisms with challenging resistance phenotypes.
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    Multicenter Evaluation of the Etest Gradient Diffusion Method for Ceftolozane-Tazobactam Susceptibility Testing of Enterobacteriaceae and Pseudomonas aeruginosa
    (American Society for Microbiology, 2018-08-27) Bailey, Adam L.; Armstrong, Tom; Dwivedi, Hari-Prakash; Denys, Gerald A.; Hindler, Janet; Campeau, Shelley; Traczewski, Maria; Humphries, Romney; Burnham, Carey-Ann D.
    Ceftolozane-tazobactam (C/T) is a novel beta-lactam–beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration in 2014 for the treatment of complicated intra-abdominal infections (in combination with metronidazole) and complicated urinary tract infections., Ceftolozane-tazobactam (C/T) is a novel beta-lactam–beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration in 2014 for the treatment of complicated intra-abdominal infections (in combination with metronidazole) and complicated urinary tract infections. In this study, we evaluated the performance of the C/T Etest, a gradient diffusion method. C/T Etest was compared to broth microdilution (BMD) for 51 Enterobacteriaceae challenge isolates and 39 Pseudomonas aeruginosa challenge isolates at three clinical sites. Essential agreement (EA) between the methods ranged from 47 to 49/51 (92.2 to 96.1%) for the Enterobacteriaceae, and categorical agreement (CA) ranged from 49 to 51/51 (96.1 to 100.0%). EA and CA for P. aeruginosa were 100% at all sites. The C/T Etest was also compared to BMD for susceptibility testing on 966 clinical isolates (793 Enterobacteriaceae, including 167 Klebsiella pneumoniae and 159 Escherichia coli isolates, in addition to 173 P. aeruginosa isolates) collected at four clinical sites. EA between Etest and BMD was 96.9% for Enterobacteriaceae isolates and 98.8% for P. aeruginosa isolates. Within the Enterobacteriaceae, isolates from each species examined had >96% CA. For the clinical isolates, no very major errors were identified but two major errors were found (one for K. pneumoniae and one for Providencia rettgeri). By BMD, 47.0% of Enterobacteriaceae and 46.2% of P. aeruginosa challenge strains were nonsusceptible to C/T by CLSI breakpoint criteria; 8.2% of clinical Enterobacteriaceae isolates and 12.1% of clinical P. aeruginosa isolates were nonsusceptible to C/T by CLSI breakpoint criteria. In conclusion, Etest is accurate and reproducible for C/T susceptibility testing of Enterobacteriaceae and P. aeruginosa.
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    Multicenter Evaluation of the Portrait Staph ID/R Blood Culture Panel for Rapid Identification of Staphylococci and Detection of the mecA Gene
    (American Society for Microbiology, 2017-04) Denys, Gerald A.; Collazo-Velez, Vanessa; Young, Stephen; Daly, Judy A.; Couturier, Marc Roger; Faron, Matthew L.; Buchan, Blake W.; Ledeboer, Nathan; Pathology and Laboratory Medicine, School of Medicine
    Bloodstream infections are a leading cause of morbidity and mortality in the United States and are associated with increased health care costs. We evaluated the Portrait Staph ID/R blood culture panel (BCP) multiplex PCR assay (Great Basin Scientific, Salt Lake City, UT) for the rapid and simultaneous identification (ID) of Staphylococcus aureus, Staphylococcus lugdunensis, and Staphylococcus species to the genus level and the detection of the mecA gene directly from a positive blood culture bottle. A total of 765 Bactec bottles demonstrating Gram-positive cocci in singles or clusters were tested during the prospective trial at 3 clinical sites. The Portrait Staph ID/R BCP results were compared with results from conventional biochemical and cefoxitin disk methods performed at an independent laboratory. Discordant ID and mecA results were resolved by rpoB gene sequencing and mecA gene sequencing, respectively. A total of 658 Staphylococcus species isolates (S. aureus, 211 isolates; S. lugdunensis, 3 isolates; and Staphylococcus spp., 444 isolates) were recovered from monomicrobial and 33 polymicrobial blood cultures. After discrepant analysis, the overall ratios of Portrait Staph ID/R BCP positive percent agreement and negative percent agreement were 99.4%/99.9% for Staphylococcus ID and 99.7%/99.2% for mecA detection.
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    Propionibacterium acnes, Coagulase-Negative Staphylococcus, and the "Biofilm-like" Intervertebral Disc
    (Wolters Kluwer, 2016-12-15) Coscia, Michael F.; Denys, Gerald A.; Wack, Matthew F.; Department of Pathology and Laboratory Medicine, IU School of Medicine
    STUDY DESIGN: Patients scheduled for spinal surgery were screened prospectively for a microbial presence associated with intervertebral disc specimens. Inclusion was limited to patients requiring surgery for any of five conditions: study patients with cervical spine intervertebral herniation (IVH), lumbar spine IVH, lumbar spine discogenic pain, and control patients with idiopathic scoliosis/Scheurermann's kyphosis or trauma/neuromuscular deformity. Exclusion criteria included ongoing systemic infection, abnormal pre-operative white cell counts, documented or suspected spinal infection, or previous surgery to the involved disc. OBJECTIVE: The aim of this study was to test for an association between the presence of a bacterial entity in operated discs and a diagnosis of pathologic disc disease. SUMMARY OF BACKGROUND DATA: An association has been described between microbial colonization and progressive intervertebral disc degeneration in 36 herniation patients undergoing microdiscectomies. A total of 19 patients had positive cultures on long-term incubation, with Propionibacterium acnes present in 84% of discs. MATERIALS AND METHODS: Discs were harvested during surgery, using strict sterile technique. Each disc was divided, with half the sample sealed in a sterile, commercially prepared anaerobic culture transport container, and half fixed in formalin. Live specimens were cultured for bacteria at a university-affiliated laboratory in a blinded fashion. Fixed pathologic specimens were gram-stained and read by a board-certified pathologist. RESULTS: A total of 169 intervertebral discs from 87 patients were evaluated (46 males, 41 females). Positive cultures were noted in 76 of 169 discs (45%), with 34 discs positive for P. acnes and 30 discs positive for Staphylococcus. No pathologic evidence was seen of microorganisms, acute or chronic inflammation, or infection. Pooling the IVH and discogenic pain patients and contrasting them with control patients showed a significant association of IVH with positive bacterial cultures (χ = 15.37; P = 0.000088). CONCLUSION: Endemic bacterial biofilms are significantly associated with IVH and discogenic pain.
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    Validation of the Bio-Response Solutions Human-28 Low-Temperature Alkaline Hydrolysis System
    (Mary Ann Liebert, 2019) Denys, Gerald A.; Pathology and Laboratory Medicine, School of Medicine
    Introduction: High temperature alkaline hydrolysis (AH) is recognized as an alternative method for sterilization and disposition of animal carcasses and human remains. The aim of this study is to validate the low temperature (LT) AH process specific to its use in the Bio-Response Solutions, Inc. Human-28 LT System. Methods: A 313-lb pig was processed using the manufacturers recommended cycle parameters. Stainless steel sample vials containing spore suspensions of Geobacillus stearothermophilus were implanted into the pig's deep tissue to validate the efficacy of the process conditions. Spore suspensions of Bacillus thuringiensis were suspended in the vessel headspace to validate sterilization. The spore challenge was greater than the recommended 106 log used to determine sterilization. MALDI-TOF mass spectrometry analysis was used to validate the destruction of prion-sized particles in processed effluent. Results: Complete inactivation of spores and digestion of animal tissue were achieved after processing in the Bio-Response Solutions Human-28 LT Alkaline Hydrolysis System. Complete inactivation of spores was achieved when exposed to heat in the animal carcass and headspace. No peptide fragments larger than 2500 Da were observed in the treatment effluent. Discussion: The Bio-Response Solutions, Inc. Human-28 LT Alkaline Hydrolysis System was as effective as high-temperature alkaline hydrolysis for use on animal and human tissue. Conclusion: LT AH for tissue and bodies exceeded the sterility assurance level III of the US State and Territorial Association on Alternative Treatment Technologies and sterility requirements for animal biosafety level-3 and -4 facilities. LT AH process validated destruction of prion-sized particles.