Labeling of the compound imidazolium with I-131 and evaluation of its infection detection potential

Infection diseases have been still the major causes of global mortality and morbidity. The researchers have been directed to design and synthesize of new more effective antimicrobial compounds due to the gaining resistance to the antibiotics of the microorganisms. It is possible to detect the changes that are physiological and biochemical occurred in the early stages of inflammative processes with the noninvasive methods used in the nuclear medicine. The radiopharmaceuticals (chemotactic peptides, antibiotics, germ inhibitor peptides, etc.) can be labeled with a variety of radionuclides (67Ga, 99mTc, 111In, 18F, 131I, etc.). Imaging techniques used for its diagnostic stage are Positron Emission Tomography (PET), Single Photon Emission Tomography (SPECT) and Magnetic Resonance Spectroscopy (MRS). The aim of this study is label compound of Imidazolium-TFSI (ITFSI) synthesized which has antibacterial effect, with the 131I and to research the potential of the labeled compound, which can be used as an agent of nuclear imaging on the detection of the bacterial infections which are Gram positive Staphylococcus aureus (S. aureus) and Gram negative Escherichia coli (E. coli). With this purpose; the compound ITFSI was labeled with 131I and the antimicrobial efficiency of the radioiodinated ITFSI compound was determined against standard origin of Gram positive S. aureus and Gram negative E. coli via in vitro binding assays. In this study, ITFSI compound was labeled with 131I via iodogen method. According to the results of the quality control studies, it is determined ITFSI compound was labeled with 131I with a high efficiency (95.5% ± 2.3). In order to determine the antimicrobial effectiveness of the compound, MIC (Minimum inhibitory concentration) values in these bacteria were determined (MIC values =1,875 μM for E. coli and S .aureus). The characteristic of antibiofilm of the compound ITFSI was searched. It is observed the compound has an effectiveness to reproduce biofilm and grow biofilm on the standard origin of S. aureus, on the contrary it has no biofilm effectiveness on the standard origin of E. coli. In in vitro uptake experiments in the bacteria orgin, the maximum uptake rates of 131I-ITFSI compound were 92,3±7,7 % (1 hour) for S. aureus and 80,1±1,5 % (2 hour) for E. coli. It is observed that the uptakes decreased with increasing incubation time. When the results are evaluated, 131I labelled with the ITFSI as a reason of showing high uptake in both bacteria for detection of infection 131I-TFSI compound is likely to be used as a nuclear imaging agent. Keywords: imidazolium-TFSI, 131I, antibacterial activity, detection of infection, S. aureus, E. coli