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.
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)
Physiological functions of Dalanine carboxypeptidases in Escherichia coli by Anindya S Ghosh ©, Chiranjit Chowdhury and David E. Nelson, [Communicating Author ©] Trends in Microbiology 16(7) 309-317 (2008)
A single amino acid substitution in the OMEGA-like loop of E. coli PBP5 disrupts its ability to maintain cellshape and intrinsic beta-lactam resistance by Mouparna Dutta, Debasish Kar, Ankita Bansal, Sandeep Chakraborty, Anindya S Ghosh © [Communicating Author ©] MICROBIOLOGY (SGM-UK) 161 (4) 895-902 (2015)
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)
A putative lowmolecular mass (LMM) penicillinbinding protein (PBP) of Mycobacterium smegmatis exhibits prominent physiological characteristics of DDCarboxypeptidase and beta-lactamase by Ankita Bansal, Debasish Kar, Rajagopal A Murugan, Sathi Mallick, Mouparna Dutta, Satya Deo Pandey, Chiranjit Chowdhury and Anindya S. Ghosh © [Communicating Author ©] MICROBIOLOGY (SGM-UK) 161 (6) 1081-1091 (2015)
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., Das J. , Verma J. , Mathew S. , Maiti T. K., Ghosh A. S. Microbes and Infection - (Accepted/In-Press)
Sub-inhibitory cefsulodin sensitization of E. coli to beta-lactams is mediated by PBP1b inhibition by Sujoy Sarkar, Mouparna Dutta, Akash Kumar, Dhriti Mallik and Anindya S Ghosh © [Communicating Author ©] PLoS One 7 (11) - (2012)
Helical disposition of protein and lipopolysaccharide in the outer membrane of Escherichia coli by Anindya S. Ghosh and Kevin D. Young Journal of Bacteriology 187 (6) 1913-1922 (2005)
Branching sites and morphological abnormalities behave as ectopic poles in shapedefective Escherichia coli by Trine Nilsen *, Anindya S. Ghosh*, Marcia B. Goldberg and Kevin D. Young (* Co-First Author) Molecular Microbiology 52 (4) 1045-1054 (2004)
Potential Utilities of Bacterial Microcompartments at Harsh Reaction Conditions Employed in Biocatalytic Industries Science and Engineering Research Board (SERB)
Molecular Analysis of Emerging Carbapenem Hydrolysing Class D Beta-Lactamases (CHDLs) in Gram Negative Bacteria and their Control using Anti Plasmid Compounds DBT, NEW DELHI
Area of Research: Beta-lactam interactive enzymes
Area of Research: Antimicrobials
Area of Research: Antibacterial resistance
Area of Research: Antimicrobial chemotherapy
Area of Research: Molecular mechanisms of antimicrobial resistance
Aditya Prasad Panda
Area of Research: Microbes and infection
Area of Research: Antimicrobial chemotherapy
Area of Research: Molecular microbiology