Rivals Jean-Paul, Béal Catherine, Thammavongs Bouachanh, Guéguen Micheline, Panoff Jean-Michel
Laboratoire de Microbiologie Alimentaire, IBFA-ISBIO, Université de Caen Basse-Normandie, 14032 Caen cedex, France.
Cryobiology. 2007 Aug;55(1):19-26. doi: 10.1016/j.cryobiol.2007.04.003. Epub 2007 Apr 21.
This study aimed to relate the acquisition of different antibiotic resistances and the corresponding physiological responses to cold stress of Lactobacillus delbrueckii subsp. bulgaricus strain CFL1. Six resistant mutants were spontaneously obtained and studied depending on the target of the antibiotic: (i) bacitracin and vancomycin (Bac(R), Van(R), wall synthesis), (ii) novobiocin (Nov(R), DNA replication), and (iii) kanamycin, spiramycin, streptomycin (Kan(R), Spi(R), Str(R), RNA translation). The mutations modified the growth and the cold stress response at three different physiological levels: (i) Van(R) and Spi(R) mutants showed significant lower growth rates compared to the wild type strain. (ii) Van(R) and Bac(R) mutants displayed a slightly higher resistance to a freezing-thawing challenge whereas Str(R) and Spi(R) mutants were more sensitive compared to the wild type. (iii) The recovery of acidification activity after freezing and during frozen storage was improved by considering the Nov(R) strain, but not with the Van(R) and Spi(R) mutants. Thus, acquisition of some antibiotic resistance by spontaneous mutation led to modification of the cold stress response. The hypothesis of a unique cellular thermostat is discussed regarding the diversity of the tested antibiotics.
本研究旨在探究德氏乳杆菌保加利亚亚种CFL1对不同抗生素耐药性的获得情况以及相应的冷应激生理反应。根据抗生素作用靶点，自发获得并研究了6个耐药突变体：（i）杆菌肽和万古霉素（Bac(R)、Van(R)，细胞壁合成），（ii）新生霉素（Nov(R)，DNA复制），以及（iii）卡那霉素、螺旋霉素、链霉素（Kan(R)、Spi(R)、Str(R)，RNA翻译）。这些突变在三个不同生理水平上改变了生长和冷应激反应：（i）Van(R)和Spi(R)突变体的生长速率显著低于野生型菌株。（ii）Van(R)和Bac(R)突变体对冻融挑战的耐受性略高，而Str(R)和Spi(R)突变体与野生型相比更敏感。（iii）Nov(R)菌株在冷冻后及冷冻储存期间的酸化活性恢复有所改善，但Van(R)和Spi(R)突变体则不然。因此，自发突变导致的某些抗生素耐药性的获得会改变冷应激反应。针对所测试抗生素的多样性，讨论了独特细胞恒温器的假说。
