Let's Talk Micro

Metallo-β-lactamases (MBLs) have become an increasingly important topic in clinical microbiology and infectious diseases. While these enzymes were once encountered relatively infrequently in the United States, their epidemiology is changing, with NDM-producing organisms becoming more common. What makes metallo-β-lactamases different from other carbapenemases? Why are infections caused by MBL-producing organisms particularly challenging to treat? And what new treatment options are becoming available? In this episode of Let's Talk Micro, Luis is joined by Dr. Ryan Shields and Dr. Emily Heil to discuss metallo-β-lactamases and their growing clinical significance. They explore the differences between serine β-lactamases and MBLs, review important enzymes such as NDM, VIM, and IMP, and discuss the challenges associated with treating infections caused by MBL-producing organisms. The conversation also covers emerging treatment options, including aztreonam-avibactam and cefepime-zidebactam, and highlights the importance of identifying specific carbapenemases to guide antimicrobial therapy. Join us for a discussion on the evolving landscape of metallo-β-lactamases and the essential role of the clinical microbiology laboratory in patient care. Guests: Ryan Shields, PharmD — University of Pittsburgh Emily Heil, PharmD — University of Maryland School of Pharmacy and University of Maryland Medical Center Additional Reading: McCreary EK, Heil EL, Aitken SL, et al. The global epidemiology and treatment of metallo-β-lactamase-producing gram-negative pathogens. JAC-Antimicrobial Resistance. 2026;8(5). https://pubmed.ncbi.nlm.nih.gov/42876900/ Stay connected with Let's Talk Micro: Website: letstalkmicro.com Questions or feedback? Email me at [email protected] Interested in being a guest on Let's Talk Micro? Fill out the form here: https://forms.gle/V2fT3asjfyusmqyi8 Support the podcast: Venmo Buy me a Ko-fi  

When you open CLSI M100, what are you usually looking for? Susceptibility breakpoints? But did you know there's much more information available beyond susceptible, intermediate, and resistant interpretations? In this episode of Micro Minutes, we explore useful information found throughout CLSI M100, including its tables, comments, and appendices. From intrinsic resistance and predicting susceptibility to other antimicrobials to understanding why certain agents should not be reported as susceptible, we highlight practical examples that can help clinical microbiology professionals interpret antimicrobial susceptibility results. Whether you're a student or an experienced laboratory professional, join us as we take a closer look at CLSI M100 and discover what's beyond S, I, and R.   Stay connected with Let's Talk Micro: Website: letstalkmicro.com Questions or feedback? Email me at [email protected] Interested in being a guest on Let's Talk Micro? Fill out the form here: https://forms.gle/V2fT3asjfyusmqyi8 Support the podcast: Venmo Buy me a Ko-fi  

Have you ever performed an organism identification using MALDI-TOF mass spectrometry and received a result showing multiple possible species, such as Enterobacter cloacae and Enterobacter asburiae, or Citrobacter freundii and Citrobacter werkmanii? Why does this happen? What do these organisms have in common, and why are they classified into groups or complexes? In this episode of Micro Minutes, Luis explores bacterial groups and species complexes, why they exist, and how they relate to organism identification. He discusses several familiar and lesser-known examples, including the Enterobacter cloacae complex, Acinetobacter calcoaceticus–baumannii complex, Klebsiella pneumoniae species complex, Citrobacter freundii complex, and Pseudomonas putida group. The episode also highlights the Burkholderia cepacia complex and why species-level identification can be particularly important in patients with cystic fibrosis. Finally, learn why reporting an organism at the group or complex level is often appropriate, when additional identification may be necessary, and why understanding the capabilities and limitations of your identification system matters. Stay connected with Let's Talk Micro: Website: letstalkmicro.com Questions or feedback? Email me at [email protected] Interested in being a guest on Let's Talk Micro? Fill out the form here: https://forms.gle/V2fT3asjfyusmqyi8 Support the podcast: Venmo Buy me a Ko-fi  

As artificial intelligence (AI) becomes increasingly integrated into biological research, the quality of the data used to develop these technologies is more important than ever. But what exactly is digital biology, and why does data quality matter? In this episode of Let's Talk Micro, Luis is joined by Jonathan Jacobs, PhD, Senior Director of Bioinformatics at ATCC, to explore digital biology and the challenges associated with biological and genomic data. Dr. Jacobs discusses the importance of metadata, common issues with publicly available genomic databases, and why connecting digital information to authenticated biological materials is essential for reproducibility and reliable research. The conversation also explores how data quality can affect AI models, the role of existing standards, and what researchers can do to improve the accuracy, completeness, and usefulness of the data they generate and share. And, as always, stay until the end to hear Dr. Jacobs' favorite microorganism and what makes it so fascinating to him!   Resources Learn more about ATCC: https://www.atcc.org/ Stay connected with Let's Talk Micro: Website: letstalkmicro.com Questions or feedback? Email me at [email protected] Interested in being a guest on Let's Talk Micro? Fill out the form here: https://forms.gle/V2fT3asjfyusmqyi8 Support the podcast: Venmo Buy me a Ko-fi  

Many microbiology professionals are familiar with ATCC strains used for quality control, validation, and verification—but what happens before those biological materials reach the laboratory? ATCC, the American Type Culture Collection, maintains biological materials used by scientists and laboratories around the world. In this episode of Let's Talk Micro, Luis is joined by Dr. Shahin Ali, Senior Scientist at ATCC, to take a closer look at the work behind biological reference materials. Dr. Ali discusses how ATCC identifies and acquires microorganisms, what characteristics are considered when adding them to the collection, and how materials are authenticated, characterized, preserved, and maintained over time. The conversation also explores expert curation and complete provenance, why authenticated reference materials are important for laboratory quality and reproducibility, and how individual strains of the same species can have meaningful differences. Luis and Dr. Ali also discuss antimicrobial resistance, the growing importance of genomic and metadata quality, and how curated biological collections may support AI-driven research in the future. And, as always, stay until the end to hear Dr. Ali's favorite microorganism—and the personal connection behind his answer. Resources Learn more about ATCC: https://www.atcc.org/ Stay connected with Let's Talk Micro: Website: letstalkmicro.com Questions or feedback? Email me at [email protected] Interested in being a guest on Let's Talk Micro? Fill out the form here: https://forms.gle/V2fT3asjfyusmqyi8 Support the podcast: Venmo Buy me a Ko-fi