Background & objectives: During lifetime, hair follicles undergo three cyclic changes: anagen, catagen, telogen. In hair follicles, stem cells located in Bulge area, which is part of the outer root sheath. Bulge cells proliferate new cells in anagen phase. Bulge region of hair follicle indicated as a source of stem cell for many years, but little studies done in vitro to characterize rat bulge region hair follicle stem cells.

  Methods: In this study Bulge cells of rat hair follicle were isolated and cultured, then morphological features of these cells surveyed. Nestin and CD34 as hair follicle stem cell markers, and K15 as a keratinocyte marker assessed by immunocytochemistry after one to three weeks.

  Results: In this study, we found that, 2 days after attachment of cells to floor of plates, the cells were initiated to proliferation and migration. These cells had good nestin and CD34 immunostaining, but after three week differentiation,were nestin and CD34 negative. Also these cells couldn’t express K15.

  Conclusion : Results showed that cultivated rat bulge cells, have high proliferative potential, and also could express nestin and CD34 as stem cell factors.

Background & objectives: Shigella spp. are gram negative bacteria that can cause shigellosis in human. It is important in young children as well as elderly and immunocompromised people. Threatening complications can occur in severe cases with multidrug resistance species. It has been observed that Shigella spp. have become resistant to antibiotics like other bacteria. Investigation of resistance to azithromycin, tetracycline and pattern of resistance are the objectives of this study.

Methods: Fifty isolates of Shigella spp. which have been collected from three hospitals in Tehran were studied. Isolates identified and confirmed as Shigella spp. by biochemical, serological and molecular methods (ipaH, wbgz, rfc genes). Antimicrobial susceptibility test was performed for ampicillin, azithromycin, ciprofloxacin, doxycycline, levofloxacin, minocycline, nalidixic acid, norfloxacin, streptomycin, trimethoprim-sulfamethoxazole and tetracycline by disc agar diffusion method. Minimal inhibition concentrations were performed for azithromycin and tetracycline.

Results: From a total of 50 Shigella spp. isolates, 16% of them were Shigella flexneri and 84% Shigella sonnei. The majority of isolates were multidrug resistant. The most resistance was seen to doxycycline, streptomycin, trimethoprim-sulfamethoxazole and tetracycline. Resistance to azithromycin was 6%  and all of the isolates were susceptible to norfloxacin and levofloxacin. Nine patterns of resistance were revealed to these isolates.

Conclusion: High resistance to tetracycline was observed and resistance to azithromycin as an alternative treatment choice was also considerable.