Journal of Environmental Radioactivity 147 (2015) 153e154

Contents lists available at ScienceDirect

Journal of Environmental Radioactivity journal homepage: www.elsevier.com/locate/jenvrad

Letter to the Editor

Isolation a new strain of Kocuria rosea capable of tolerating extreme conditions

Keywords: Ramsar High background radiation areas (HBRAs) Bacteria Multiple-stress conditions

Dear Editor, I read with great interest an article by A. Gholami et al. entitled “Isolation a new strain of Kocuria rosea capable of tolerating extreme conditions”, published in the Journal of Environmental Radioactivity (2015, 144, 113e119). The authors of this paper have presented their findings regarding multiple extreme resistance of a new strain of K. rosea that is capable of tolerating extreme conditions. They isolated the new strain of K. rosea from radioactive spring “Ab-e-Siah” in Ramsar, a city with the highest level of natural radioactivity in the world. Interestingly the authors reported that their isolate “Kocuria rosea MG2” showed multiple resistances to stresses such as UV-C radiation, desiccation, salt concentration, various pHs and hydrogen peroxide as an oxidizing agent. Gholami et al. have addressed a challenging issue in the field of low dose radiation. However, I would like to express my concerns regarding this paper. My colleagues and I have previously published our findings regarding the investigation of radioresistance in microorganisms collected from surface water streams in Talesh Mahalleh, a district with high levels of background radiation in Ramsar as well as a nearby area with normal levels of background radiation (Motamedifar et al., 2014). Interestingly, in our experiment, all the bacteria isolated from water samples of high and normal background radiation areas were sensitive to ultraviolet radiation, heat, betadine, alcohol, and decanex. Although Gholami et al. have not mentioned previously published papers on this topic (e.g. our paper), I believe that it would be very important to investigate the reason for observed differences in these studies. We have previously published reports on the health effects of exposure to elevated levels of natural ionizing radiation in high background radiation areas (HBRAs) of Ramsar (Mortazavi et al., 2005a, 2005b; Mortazavi and Karam, 2005; Mortazavi and DOI of original article: http://dx.doi.org/10.1016/j.jenvrad.2015.05.011. http://dx.doi.org/10.1016/j.jenvrad.2015.05.010 0265-931X/© 2015 Elsevier Ltd. All rights reserved.

Mozdarani, 2012, 2013b; Mortazavi et al., 2012; Mortazavi et al., 2005d) including the first reports on the induction of adaptive response (AR) in the residents of these areas (Ghiassi-Nejad et al., 2002). In 2002, we exposed the lymphocytes of residents of HBRAs and those from a nearby normal background radiation area (NBRA) in vitro to a challenge dose of 1.5 Gy of gamma rays and found a significantly decreased frequency of chromosome aberrations in HBRA residents compared with those of the residents of the NBRAs. It is worth mentioning that AR can be defined as the induction of repair mechanisms after a pre-exposure to a low level chemical or physical stress (e.g. ionizing or non-ionizing radiation). Our previous experiments have shown that living organisms pre-exposed to low levels of ionizing (Mortazavi et al., 2005c, 2010; Mortazavi and Mozdarani, 2006; Mortazavi et al., 2005d) or non-ionizing radiation (Haghani et al., 2013; Mortazavi, 2012, 2014; Mortazavi et al., 2011; Mortazavi and Mozdarani, 2013a) show resistance against the detrimental biological effects of a subsequent large dose (challenge dose). Although the study performed by Gholami et al. a shows typical adaptive response, the authors have not addressed this effect. It is worth mentioning that to the best of our knowledge. Our paper is the only report that showed bacteria isolated from hot springs cannot reveal any adaptive response. Another problem in this paper comes from this point that the authors have used some very old data about the physic-chemical composition of Ab-e-Siah radioactive spring “The equivalent dose around the spring was measured previously about 13.48 mSv h 1 (Dabbagh et al., 2006). The temperature of hypothermal springs ranges from 28 to 35  C so that it is classified as a hypothermal spring (Dabbagh et al., 2006)”. The authors should note that in HBRAs of Ramsar radioactivity in any location can change over the years. As we have previously discussed in detail, when the groundwater reaches the surface at hot spring locations, travertine, a calcium carbonate (CaCo3) mineral, precipitates out of solution with dissolved radium substituting for calcium in the mineral as RaCo3 (Ghiassi-Nejad et al., 2002; Mortazavi and Mozdarani, 2012). High concentrations of radium carbonate which can be found in the residual deposits of the hot springs may gradually close the old underground streams which lead to occurrence of newly developed underground streams. Therefore, in HBRAs of Ramsar the radioactivity map may significantly change over the time.

References Ghiassi-Nejad, M., Mortazavi, S., Cameron, J., Niroomand-Rad, A., Karam, P., 2002. Very high background radiation areas of Ramsar, Iran: preliminary biological studies. Health Phys. 82, 87. Haghani, M., Mortazavi, S.M.J., Sardari, D., Mosleh-Shirazi, M.A., Mansouri, A., 2013. Assessment of the role of specific absorption rate of mobile phones on the

154

Letter to the Editor / Journal of Environmental Radioactivity 147 (2015) 153e154

induction of microwave-induced survival adaptive responses after exposure to lethal doses of gamma radiation. Int. J. Radiat. Res. 11, 167e173. Mortazavi, S., Ghiassi-Nejad, M., Rezaiean, M., 2005a. Cancer risk due to exposure to high levels of natural radon in the inhabitants of Ramsar, Iran. Int. Congr. Ser. 1276, 436e437. Mortazavi, S.M.J., 2012. Space research and EMF-induced adaptive responses. J. Med. Hypotheses Ideas 7, 1e2. Mortazavi, S.M.J., 2014. Is mobile phone radiofrequency radiation all bad? J. Med. Hypotheses Ideas 8, 42e43. Mortazavi, S.M.J., Abbasi, A., Asadi, R., Hemmati, A., 2005b. The need for considering social, economic, and psychological factors in warning the general public from the possible risks due to residing in HLNRAs. Int. Congr. Ser. 1276, 440e441. Mortazavi, S.M.J., Cameron, J.R., Niroomand-Rad, A., 2005c. The life saving role of radioadaptive responses in long-term interplanetary space journeys. Int. Congr. Ser. 1276, 266e267. Mortazavi, S.M.J., Karam, P.A., 2005. Apparent lack of radiation susceptibility among residents of the high background radiation area in Ramsar, Iran: can we relax our standards? Nat. Radiat. Environ. 7, 1141e1147. Mortazavi, S.M.J., Mosleh-Shirazi, M.A., Mehdizadeh, S., Rouintan, M.S., Ebrahimi, J., Tamaddon, M., Koshnevis, M., 2010. Short-term radon inhalation induces significant survival adaptive response in Balb/c mice. Int. J. Low Radiat. 7, 98e109. Mortazavi, S.M.J., Mosleh-Shirazi, M.A., Tavassoli, A.R., Taheri, M., Bagheri, Z., Ghalandari, R., Bonyadi, S., Shafie, M., Haghani, M., 2011. A comparative study on the increased radioresistance to lethal doses of gamma rays after exposure to microwave radiation and oral intake of flaxseed oil. Iran. J. Radiat. Res. 9, 9e14. Mortazavi, S.M.J., Mozdarani, H., 2006. The search for a possible optimum adapting dose under the optimum irradiation time scheme in cultured human lymphocytes. Int. J. Low Radiat. 3, 74e82. Mortazavi, S.M.J., Mozdarani, H., 2012. Is it time to shed some light on the black box of health policies regarding the inhabitants of the high background radiation areas of Ramsar? Iran. J. Radiat. Res. 10, 111e116. Mortazavi, S.M.J., Mozdarani, H., 2013a. Deep space missions and the issue of overcoming the problem of space radiation. Int. J. Radiat. Res. 11, 199e202.

Mortazavi, S.M.J., Mozdarani, H., 2013b. Non-linear phenomena in biological findings of the residents of high background radiation areas of Ramsar. Int. J. Radiat. Res. 11, 3e9. Mortazavi, S.M.J., Niroomand-Rad, A., Mozdarani, H., Roshan-Shomal, P., RazaviToosi, S.M.T., Zarghani, H., 2012. Short-term exposure to high levels of natural external gamma radiation does not induce survival adaptive response. Iran. J. Radiat. Res. 10, 165e170. Mortazavi, S.M.J., Shabestani-Monfared, A., Ghiassi-Nejad, M., Mozdarani, H., 2005d. Radioadaptive responses induced in lymphocytes of the inhabitants in Ramsar, Iran. Int. Congr. Ser. 1276, 201e203. Motamedifar, M., Mortazavi, S., Zamani, K., Taeb, S., Mortazavi, S., Soofi, A., Haghani, M., Sedigh, H., 2014. Microbiology of the surface water samples in the high background radiation areas of Ramsar, Iran. Radiat. Prot. Environ. 37, 21e24.

S.M.J. Mortazavi* Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Iran Medical Physics & Medical Engineering Department, Shiraz University of Medical Sciences, Iran * Medical Physics & Medical Engineering Department, School of Medicine, Imam Hossein Square, Post Code: 7134845794, Shiraz, Iran. E-mail addresses: [email protected], http://home.sums.ac.ir/ ~mmortazavi, http://www.researcherid.com/rid/D-5830-2011.

16 April 2015 Available online 31 May 2015

Isolation a new strain of Kocuria rosea capable of tolerating extreme conditions.

Isolation a new strain of Kocuria rosea capable of tolerating extreme conditions. - PDF Download Free
175KB Sizes 0 Downloads 19 Views