Penicillin-interactive enzymes (PIEs) include penicillin-binding proteins (PBPs) and beta-lactamases (BLAs). PBPs catalyze the synthesis and remodeling of peptidoglycan (PG). We focus on PG-remodeling enzymes, DD-carboxypeptidases (DD-CPases), encoded by dacA, dacC, dacD and ampH. The characteristic features of DD-CPases are maintaining cell shape and intrinsic beta-lactam resistance, though there are inter and intra species variations in their physiological activities. Therefore, we intend to categorize DD-CPases thoroughly based on their physiological and biochemical functions in Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Mycobaterium smegmatis and Mycobaterium tuberculosis. Moreover, we intend to find whether these DD-CPases have any other roles, namely, in evading immunological response, biofilm formation, antibiotic resistance, etc.
As PBPs and BLA share common ancestry, through specific mutational analyses, we aim to know whether their activities are linked and identify the exact point of divergence of these two enzymes. Furthermore, we intend to probe the physiology of BLAs in bacterial cells apart from their roles in cleaving beta-lactams. Various types of BLAs, like TEM1, OXA, ESBL, Metallo-beta lactamases (MBL) and AmpC have a different spectrum of activity. Some of them are intrinsically expressed while the others need induction for proper expression. We are involved in studying the pathway of induction of these enzymes, which can be exploited to design future antimicrobial agents.
We are also involved in identifying the genes related to biofilm formation in E. coli, K. pneumoniae, A. baumannii and M. smegmatis using molecular genetics techniques. Furthermore, we are engaged in characterizing several putative efflux-pump proteins in search of efflux–pump inhibitors for designing combination therapy and intend to correlate biofilm formation with efflux-pump proteins, or BLAs or any other factors, which can lead to multi-drug resistance phenotypes. In addition, we design and validate effective antibiotic combinations and diagnostic tools for BLA detection.

All Publications

Involvement of CorA of Mycobacterium smegmatis in exerting intrinsic resistance towards structurally unrelated antibiotics by Chatterjee D., Daya Manasi A. R., Rastogi S. K., Panda A. P., Biju B. , Bhattacharyya D. , Ghosh A. S. Journal of Applied Microbiology 135 lxae29- (2024)
Deletion of penicillin-binding protein 5 (PBP5) sensitises Escherichia coli cells to beta-lactam agents by Sujoy K Sarkar, Chiranjit Chowdhury and Anindya S Ghosh © [Communicating Author ©] International Journal of Antimicrobial Agents 35 244-249 (2010)
P-type ATPase zinc transporter Rv3270 of Mycobacterium tuberculosis enhances multi-drug efflux activity by Chatterjee D., Panda A.P., Daya Manasi A.R., Ghosh A.S. Microbiology (United Kingdom) 170 001441- (2024)
Two non-active site residues W165 and L166 prominently influence the beta-lactam hydrolytic ability of OXA-23 beta-lactamase by Jain D., Verma J. , Tjavath A. , Bhattacharjee A. , Ghosh A. S. Journal of Antibiotics 76 489-498 (2023)
A NiCoT family metal transporter of Mycobacterium tuberculosis (Rv2856/NicT) behaves as a drug efflux pump that facilitates cross-resistance to antibiotics by Adhikary A., Biswal S., Chatterjee D., Ghosh A.S. Microbiology (United Kingdom) 168 - (2022)
Glutamic acid at position 152 and serine at position 191 are key residues required for the metallo- -lactamase activity of NDM-7 by Kumar G., Issa B., Biswal S., Jain D., Bhattacharjee A., Ghosh A.S. International Journal of Antimicrobial Agents 55 - (2020)
Absence of the glycosyltransferase WcaJ in Klebsiella pneumoniae ATCC13883 affects biofilm formation, increases polymyxin resistance and reduces murine macrophage activation. by Pal S., Verma J. , Mallick S. , Rastogi S. K., Kumar A. , Ghosh A. S. Microbiology 165 891-904 (2019)
Role of Escherichia coli endopeptidases and dd-carboxypeptidases in infection and regulation of innate immune response. by Mallick S., J D. , J V. , S M. , Maiti T. K., Ghosh A. S. Microbes & Infection 21 464-474 (2019)
Two DD-carboxypeptidases from Mycobacterium smegmatis affect cell surface properties through regulation of peptidoglycan cross-linking and glycopeptidolipids by Ghosh A. S., Pandey S. , Pal S. , N G. K., Bansal A. , Mallick S. Journal of Bacteriology 200 e00760--17 (2018)

Completed Projects

Principal Investigator

Deciphering the role of functional amyloid-mediated antimicrobial resistance in Escherichia coli Anusandhan National Research Foundation (ANRF)
Designing a secondary resistance based biomarker for detection of antimicrobial resistance (AMR) in multi drug resistant bacteria Department of Biotechnology
Designing a secondary resistance based biomarker for detection of antimicrobial resistance (AMR) in multi drug resistant bacteria Department of Biotechnology
Exploring the possible mechanisms of Placentrex in the inhibition of bacterial growth by assessing its effect on antimicrobial susceptibility and biofilm formation ALBERT DAVID LIMITED
Search for antibiotic-consuming bacteria for reduction of persistent antibiotic residues in the environment with a target to design and establish on-site beta-lactam bioremediation strategy Department of Biotechnology
Search for antibiotic-consuming bacteria for reduction of persistent antibiotic residues in the environment with a target to design and establish on-site beta-lactam bioremediation strategy Department of Biotechnology