Publications by authors named "Nathalie Chen"
Infect Immun
December 2024
Article Synopsis
- Hypervirulent Klebsiella pneumoniae (hvKp) strains, once thought rare in the U.S., are being increasingly reported, with a study analyzing 273 respiratory isolates from patients in Western Pennsylvania between 2020 and 2022.
- Among these, 13 (4.8%) tested positive for hypervirulent traits, with 2 strains (0.7%) confirmed to carry specific virulence genes, suggesting they can cause severe infections in the community.
- Experiments showed these hvKp strains caused significant pneumonia in mice, indicating their potential to circulate in North America and cause severe community-associated infections.
Article Synopsis
- - The study focused on KPC-Kp bloodstream infections, which are deadly, and aimed to understand how these bacteria resist a key defense mechanism in our blood, called complement.
- - Researchers tested various KPC-Kp isolates from patients, discovering that 27% of them resisted killing by human serum; a specific gene mutation (wcaJ) linked to capsule production contributed to this resistance.
- - This mutation resulted in less capsule presence, paradoxically increasing the bacteria's ability to bind complement proteins while also improving their survival against immune responses, potentially allowing them to thrive in the bloodstream without being overly virulent in tissues.
PLoS Pathog
December 2023
Article Synopsis
- * gp120 also interacts with the integrin ⍺4β7, which is found on certain memory CD4+ T cells, suggesting that this relationship is important for HIV's preference for these immune cells and gut tissues.
- * The study reveals that CD4 binds to ⍺4β7 dynamically, with specific binding sites that are crucial for both gp120's attachment to CD4 and its entry into cells, indicating that the interaction between CD4 and ⍺4β7 is critical
Article Synopsis
- *Researchers found that 27% of KPC-Kp isolates showed increased resistance to human serum, linked to a mutation that reduces capsule content and helps the bacteria evade immune responses.
- *The mutation allows KPC-Kp to survive better in the bloodstream while being less virulent in tissues, highlighting a complex interaction that aids the bacteria's persistence in the host.
Sci Transl Med
October 2019
Article Synopsis
- * Analysis of heart tissue from an infant with tetralogy of Fallot with pulmonary stenosis (ToF/PS) showed an increase in cardiomyocyte cytokinesis failure, linked to repression of the ECT2 gene due to β-adrenergic receptor activity.
- * Using β-blockers like propranolol was found to increase cardiomyocyte division, suggesting the potential for these drugs to help improve heart function and recovery in patients with ToF/PS and other forms of CHD.
