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Kim Walker

@drwalkermsbanta.bsky.social

Associate Prof at UNC-Chapel Hill studying Klebsiella virulence.

22 Posts1052 Follower240 Folgt
Juan David Valencia Bacca@juanvalenciabacca.bsky.social · 9mo ago

journals.asm.org/doi/10.1128/... Proud to see our work published in mBio! We uncover how C3 and C4 provide layered immune protection against Klebsiella pneumoniae. Grateful for my incredible mentors Dr. Ammar Zafar @azmicro.bsky.social, Dr. Karen Haas and supportive colleagues.

Divergent roles for complement components C3 and C4 in controlling Klebsiella pneumoniae gut colonization and systemic dissemination | mBio

Klebsiella pneumoniae, a major public health threat, resists antibiotics and can spread from the gut to the bloodstream, causing severe infections. Our study reveals how the immune system uses complement proteins C3 and C4 to block this spread. C3 limits bacterial growth in the gut through two potential mechanisms: (i) coating K. pneumoniae with fragments that signal bacteria-eating phagocytic cells to destroy it and (ii) recruiting more phagocytes into the gut. C3 also helps clear bacteria that escape into the blood. However, when antibiotic-resistant strains overgrow, C3 alone is insufficient. In these cases, C4 becomes critical, likely by enhancing C3’s ability to tag bacteria for elimination. This two-layered defense highlights new immune pathways that could be targeted to prevent bloodstream infections, especially in vulnerable patients or those colonized with drug-resistant bacteria. These insights open doors to innovative strategies against life-threatening Klebsiella infections.

journals.asm.org

Kim Walker@drwalkermsbanta.bsky.social · 10mo ago

The latest in our quest to understand the role of HMV and hypercapsule in convergent Klebsiella is out! So thankful to this team for making this project really fun! @stphnslsbry.bsky.social @leslieannaerobe.bsky.social @margaretlam.bsky.social @katholt.bsky.social journals.asm.org/doi/10.1128/...

The acquisition of rmpADC can increase virulence of classical Klebsiella pneumoniae in the absence of other hypervirulence-associated genes | mBio

Klebsiella pneumoniae is a global pathogen, and gene exchange between hypervirulent (hvKp) and classical (cKp) strains is a rising threat. It is essential to understand how hvKp genes impact virulence phenotypes and identify the cKp strain backgrounds most amenable to enhanced virulence. Hypermucoviscosity (HMV) is a critical virulence factor in hypervirulent K. pneumoniae, conferred by the rmpADC locus. The rmp genes are encoded on mobile genetic elements and have been detected in convergent antibiotic-resistant K. pneumoniae strains of concern. In this study, we explored the impact of rmp acquisition in a broad set of classical clinical isolates. We observed that HMV appears necessary, but not sufficient, for increased virulence. Sequence type, capsule type, and HMV capacity could not predict which classical isolates gain an rmp-dependent colonization benefit. These insights increase our understanding of the distinctions between cKp and hvKp and further our ability to identify and treat new strains of concern.

journals.asm.org

Juan David Valencia Bacca@juanvalenciabacca.bsky.social · last yr.

currentprotocols.onlinelibrary.wiley.com/doi/10.1002/... Our new article in Current Protocols is out: Microbiologists, immunologists, host-pathogen folks: this one’s for you 🧬🦠 #Klebsiella #HostPathogen #Microbiology Huge thanks to my mentor @azmicro.bsky.social for the guidance and support!

Murine Models of Klebsiella pneumoniae Gastrointestinal Infection

Klebsiella pneumoniae (Kpn) is a Gram-negative opportunistic pathogen and a leading cause of hospital-acquired infections. The gastrointestinal (GI) tract serves as a critical site for Kpn colonizati....

currentprotocols.onlinelibrary.wiley.com

Kelly Wyres@kelwyres.bsky.social · last yr.

So excited that this is now online. It's been a huge collaborative effort to estimate the prevalence of capsule and O antigens associated with #klebsiella neonatal sepsis in Africa and South Asia. The first step to prioritising antigens for a vaccine to protect 1000s of newborns. #MicroSky #AMR

Kat Holt@katholt.bsky.social · last yr.

I'm super happy to share this preprint on ‘Distribution of capsule and O types in #Klebsiella pneumoniae causing neonatal sepsis in Africa and South Asia: meta-analysis of genome-predicted serotype prevalence and potential vaccine coverage’ doi.org/10.1101/2025...

Caity Holmes@caityholmes.bsky.social · 2y ago

It's that time of year! Registration and abstract submission for the 6th Klebsiella Seminar Series is now open. Participation is free and abstracts are due by February 16th. See the link below for details, and reach out to the organizers with any questions: forms.gle/gxbvaC6FjzuS... #KlebClub

Klebsiella Seminar Series 2025

This form can be used to register only or register+submit an abstract for the 2025 Klebsiella Seminar Series. By registering, you will receive a Zoom Webinar link for attendance prior to the event. Re...

forms.gle