Klas Ifeanyi Udekwu

My graduate studies were in the department of Cell and Molecular Biology in Uppsala University, Sweden.

My Master's research was on tRNA identity under the supervision of Professor Leif Kirsebom.

The title of my PhD dissertation which I did under the direction of Professor E Gerhart Wagner is  “Functional characterization of the small Antisense RNA MicA in Escerichia coli”.   In that investigation,  I discovered the target of a (then) newly identified small RNA with the help of global screening methodology.   My collaborators and I then characterized the mode of interaction and post-transcriptional control exerted by this antisense RNA on its target, a long-lived mRNA encoding the OmpA outer membrane porin. I went on to chart the transcriptional profile of this small RNA in response to various disfavourable environmental conditions and showed it to be under exclusive control of the membrane stress-related sigma factor, σE.

My postdoctoral research involves the application of the tools of population and molecular biology to improving the success of antibiotic treatment and understanding the mechanisms of antibiotic action.  My current research includes theoretical, in vitro and laboratory animal experiments.  Of particular concern in these studies are the effects of the density and physiological state of Staphylococcus aureus on the in vitro pharmacodyanamics of antibiotics of different classes their their implications for therapy.   The results of my studies have raised a number of questions about the mechanisms by which antibiotics of different classes kill and/or inhibit the growth of bacteria and their response to stress which I will also be addressing.

Publications

Udekwu, K,  N. Parrish, P. Ankomah, , F. Baquero and BR Levin (2009) Functional Relationship Between Cell Density and the Efficacy of Antibiotics. Journal of Antimicrobial Chemotherapy 63:745-767 [PDF]

Udekwu, K. et al., 2005. Hfq-dependent regulation of OmpA synthesis is mediated by an antisense RNA, Genes & Development 1;19(19):2355-66.

Udekwu, K. & Wagner, 2007. Sigma E controls biogenesis of the antisense RNA MicA, Nucleic Acids Research 35(4):1279-88

Posters

The physiological state of bacteria and the efficacy of antibiotics: an experimental and modeling odyssey.  Microbial Population Biology Gordon Conference, July 2009 [PDF]