KARAN BAMB

Molecular Biologist with expertise in bacterial biofilms and antibiotic resistance/tolerance. Conducted extensive academic research on biofilm formation mechanisms and their role in antimicrobial persistence. Proficient in designing and executing experiments to evaluate antibiotic efficacy against biofilm-associated bacteria. Skilled in data acquisition and analysis, scientific writing, and interdisciplinary collaboration.

• Received best poster presentation at Eastern Pennsylvania Branch of the American Society for Microbiology (EPAA-ASM) 2024
• Presented my Masters’ poster at Discovery Day 2023, Drexel University, USA
• Presented my Honors’ poster at Combined Biological Sciences Meeting (CBSM)
• Presented ‘The Human Microbiome Project” at Curtin University, September 2016

• Joshua Chang Mell, Ph.D., Associate Professor, Department of Microbiology & Immunology, Drexel University, Philadelphia, PA, jcm385@drexel.edu
• Donald C. Hall Jr., Ph.D., Assistant Professor, Department of Microbiology & Immunology, Drexel University, Philadelphia, PA, dch66@drexel.edu
• Garth D. Ehrich, Ph.D., Professor of Microbiology & Immunology, Department of Microbiology & Immunology, Drexel University, Philadelphia, PA, ge33@drexel.edu

Multidrug Tolerance and the Stringent Response in Diverse Clinical Isolates of Haemophilus influenzae.

Drexel University, Philadelphia, USA, 07/2023 - 08/2024

Biofilm-induced multidrug tolerance (MDT) presents a significant challenge to treatment and leads to persistent infections. This study investigated the role of the stringent response in MDT in Haemophilus influenzae, which causes persistent ear and lung infections. A panel of 12 genomically diverse clinical isolates, as well as lab-made mutants lacking the relA and spoT genes were examined for biofilm formation, antibiotic susceptibility, and MDT. Results revealed substantial variation in biofilm cell densities and MDT profiles among strains. Deletion of stringent response genes had little effect on biofilm formation but significantly reduced MDT in the lab strain Rd, confirming the pathway's importance. Treatment with HEJ14, a putative RelA inhibitor, generally decreased MDT across strains but with varying efficacy. Surprisingly, HEJ14 also reduced MDT in stringent response mutants, suggesting it may target a downstream effector of (p)ppGpp. While the stringent response contributes to biofilm-induced MDT in H. influenzae, the residual survival in mutants and variable effects of HEJ14 indicate the involvement of additional pathways to MDT that vary among clinical strains. This study highlights the potential of stringent response inhibitors as adjunct therapies for persistent infections while emphasizing the complexity of MDT mechanisms. Further investigation is needed to elucidate the precise mode of action of HEJ14 and to identify other contributing factors to MDT. 

Make Antibiotics Great Again: Investigations into transient antibiotic resistance in bacteria exposed to antimicrobial peptides.

Curtin University, Perth, Australia, 01/2019 - 11/2019. 

Staphylococcus aureus is a Gram-positive pathogenic bacterium. Methicillin-resistant S. aureus (MRSA) has become a serious public health concern since its emergence and global dissemination. Antimicrobial peptides (AMPs) are also known as host defense peptides and have rapid and broad-spectrum antimicrobial activity. This study investigated the propensity for collateral sensitivity or cross resistance to develop in MRSA strains exposed to melittin over seven days. Amongst all the samples included in this study we can say that collateral sensitivity likely developed in the week one replicates and could not be reproduced in the week two replicate. Based on our results we found that collateral sensitivity was rare and not universal.