Journal of Knowledge & Health1735-577X13420190311Evaluation of siderophore production in Streptococcus pneumoniae by chrome azurol S method273110.22100/jkh.v13i4.2090FAFereshtehEbrahimi 11- Dept. of Medical laboratory sciences, School of paramedical sciences, Zanjan University of Medical Sciences, Zanjan, Iran.. ebrahimyf1395@gmail.comMozhganKheirandish 2MoslemJafari Sany 3Davoud0000-0002-3259-3790Afshar 2*201811172019012220190114Introduction: Iron is one of the vital elements for pathogenic bacteria. Some bacteria produce proteins called siderophore, which have high affinity to bind iron and absorb it from many glycoproteins such as transferrin and lactoferrin. The aim of the present study was to investigate the ability of siderophore production in Streptococcus pneumoniae using the chrome azurol S(CAS) method.Methods: The production of siderophore was measured by chrome azurol S method. Sediment of tested bacteria was added into microtube containing CAS solution and then incubated at 25C for 2h. The optical densities (OD) of samples were measured at 630 nm. Bacillus subtilis ATCC 11778 was used as a positive control for siderophore production.Results: The OD rate for S. pneumoniae and B. subtilis was 0.043 and -0.016, respectively.Conclusion: According to results, it seems that S. pneumoniae is not able to produce siderophore. Therefore, it is possible that the bacterium absorbs iron from other iron sources such as lactoferrin, transferrin and ferritin.