Adaptation of Propionibacterium acnes to environmental stresses

초록

Propionibacterium acnes is a typically aerotolerant anaerobic Gram positive bacterium that can cause acne [1]. Many bacteria exhibited adaptation to various environmental stresses where pretreatment with sublethal level of stress induced resistance to subsequent lethal level of same or other stresses [2]. As there is little study on adaptation of P. acnes we examined whether P. acnes also exhibits adaptation phenomenon toward various stresses. A sublethal dose of ethanol (8%, vol/vol), acid (pH 5), H2O2 (0.01%, vol/vol), or NaCl (14%, wt/vol) was applied to a P. acnes KCTC 3314 culture, and the cells were allowed to grow for 0 to 1h. The stress-adapted cells were then subjected to the following lethal level of stresses - NaCl (25%, wt/vol), ethanol (12%, vol/vol), H2O2 (0.1%, vol/vol), and acid (pH 3). Viablility of P. acnes was measured by plate counting on BHI agar, and % survival rates were plotted. Adaptation to 14 % NaCl significantly increased the resistance to NaCl, acid, ethanol, and H2O2 indicating cross-protection. Addition of chloramphenicol (translation inhibitor) during NaCl pretreatment prevented the development of resistance to lethal stresses suggesting that NaCl-induced cross-protection requires de novo protein synthesis. References [1] Masahiko Nakamura, et al., Identification of Propionibacterium acnes by polymerase chain reaction for amplification of 16S ribosomal RNA and lipase genes (2003) Anaerobe 9:5-10 [2] Bouachanh Thammavongs, Jean-Michel Panoff, Micheline Gue´guen. Phenotypic adaptation to freeze–thaw stress of the yeast-like fungus Geotrichum candidum (2000) International Journal of Food Microbiology 60:99-105