Please read this informative blog post by clinical microbiology and postdoctoral fellow, Thea Brennan-Krohn: "AST FOR NEW ANTIBIOTICS: THE CLINICAL LABORATORIAN'S DILEMMA."
Congratulations to Anthony Kang, PhD, and colleagues on our publication: "In Vitro Apramycin Activity Against Multidrug-Resistant Acinetobacter baumannii and Pseudomonas aeruginosa" published online today in Diagnostic Microbiology and Infectious Disease
The manuscript highlights the remarkable activity of apramycin against multidrug-resistant, extensively drug resistant and pandrug-resistant Acinetobacter and Pseudomonas. Both organisms are significant multidrug-resistance threats. Importantly, frank resistance to apramycin was observed in < 2% of isolates. Apramycin is an aminocyclitol-based aminoglycoside that is currently approved for veterinary use. The activity in these groups of bacteria was especially notable in light of the high level of resistance of the same strain set to aminoglycosides (amikacin, gentamicin, tobramycin) approved for human use. This study complements our prior study, also published in DMID, demonstrating activity of apramycin against a high proportion of carbapenem-resistant Enterobacteriaceae strains.
Congratulations to Postdoctoral Fellow Yoon-Suk Kang on publication of his manuscript "Promotion and Rescue of Intracellular Brucella neotomae Replication During Co-Infection With Legionella pneumophila"
Published online today in Infection and Immunity: "Promotion and Rescue of Intracellular Brucella neotomae Replication During Co-Infection With Legionella pneumophila." Yoon-Suk created a versatile bioreporter toolkit to enable analysis of the fate of individual pathogens in polymicrobial infections. He then validated a type IV secretion system-dependent Brucella model using the wood rat pathogen, Brucella neotomae. In contrast to wild type organisms, Brucella T4SS mutants were completely defective in their ability to growth inside of macrophages. Fascinatingly co-infection with Legionella pneumophila, another T4SS-dependent pathogen, was able to rescue intracellular growth of the T4SS-mutant Brucella and also stimulated growth of wild type Brucella organisms! This was a one way rescue: Legionella could rescue Brucella, but wild type Brucellla could not rescue T4SS-defective Legionella.
See discussion of our work on Microscopy-Based Antimicrobial Susceptibility Testing as part of the Harvard Catalyst Reactor Pilot Program.
Thea received an ASM Infectious Disease Travel Award and KP Smith an ASM Postdoctoral Travel Award. Both prestigious ASM Travel Awards are based on abstract submissions to the 2017 ASM MIcrobe Meeting in New Orleans. Jennifer Tsang will be joining the crew with an abstract acceptance on her high throughput screening work..
We are competing in the STAT Madness competition for Innovations in Biomedical Science. Please vote for us!!!!
Here is the link to to the STAT Madness competition: www.statnews.com/feature/stat-madness/bracket/. Please vote for BIDMC in the line up. Our research on discovery of antimicrobials targeting carbapenem-resistant Enterobacteriaceae is highlighted. See "Validation of a High-Throughput Screening Assay for Identification of Adjunctive and Directly Acting Antimicrobials Targeting Carbapenem-Resistant Enterobacteriaceae" published in Assay and Drug Development Technologies and accompanying editorial for more information."
We describe a very unusual Candida guilliermondii pseudo-outbreak related to undermining of petri dish swan neck barriers by the Advanced Anoxomat System used in many clinical laboratories to set up anaerobic cultures
In the Journal of Clinical Microbiology, we describe an unusual Candida pseudo-outbreak that based on patterning on culture plates mimicked true infection. Specifically, colonies were not randomly distributed on plates, but demonstrated in a graded pattern typical of true infections with decreasing number of colonies on subsequent quandrants of streak plates. The culprit was eventually identified, as a contaminated Anoxomat chamber that was used to hold anaerobic plates prior to use in cultures. The Anoxomat rapidly purges and instills a hydrogen/nitrogen gas mixture into a closed jar in order to rapidly establish anaerobiosis. We believe that the Anoxomat overcame the natural swan neck barrier of Petri dishes allowing Candida guilliermondii containing aerosols to randomly contaminate anaerobic plates. C. guilliermondii does not grow anaerobically obscuring this contamination. However, randomly contaminated anaerobic plates were subsequently the source of contamination for the primary quandrants of aerobic media during specimen planting leading to simulation of true infection by microbiological criteria. Pseudo-outbreak strains were proven clonal by a combination of pulsed-field gel electropheresis and optical restriction mapping. The study represented a combined effort of the clinical microbiology laboratory and the infection control/hospital epidemiology divisions at BIDMC; Dan Diekema at the University of Iowa (PFGE analysis and expertise); and OpGen (optical mapping).
I was selected as a SLAS 2017 Innovation Award Finalist and will be speaking at the SLAS Annual Meeting with a presentation titled: "Inkjet Printing Technology for Facilitated At Will Antimicrobial Susceptibility Testing (FAST) in Under 5 Hours: Addressing the Needs of a So-Called 'Post-Antibiotic Era'.
"Improved Accuracy of Cefepime Susceptibility Testing for ESBL-producing Enterobacteriaceae using an On-Demand Digital Dispensing Method" published online yesterday in the Journal of Clinical Microbiology
Co-First Authors, KP Smith and Thea Brennan-Krohn, from the Kirby Research Laboratory and Susan Weir from the BIDMC Clinical Microbiology Laboratory collaboratively investigated the ability of commonly used clinical methods to support new "susceptible dose-dependent." MIC breakpoints newly introduced by the Clinical Laboratoryand Standards Institute for the antibiotic cefepime. The idea behind these SDD breakpoints was to offer clinicians the chance to treat otherwise poorly susceptible pathogens by increasing the cefepime dose in a manner tied to the isolate's MIC. To perform the study, we enriched for strains that should have borderline cefepime susceptibility based on a ceftriaxone resistant phenotype. Surprisingly, three commercial methods (Vitek 2, disk diffusion, and a manual microscan panel) performed poorly with only 40-60% categorical agreement with the broth microdilution reference standard. In contrast, the Digital Dispensing Method, (DDM) previously described by our laboratory was stastically equivalent to the reference method, and therefore was the only method capable of supporting susceptible dose dependent therapeutic rescue. The manuscript, "Improved Accuracy of Cefepime Susceptibility Testing for ESBL-producing Enterobacteriaceae using an On-Demand Digital Dispensing Method" can be found on the Journal of Clinical Microbiology website.