PDF(Pubmed)
Abstract：
UNASSIGNED: This study is the final part of a two-part series that delves into the molecular mechanisms driving adaptive laboratory evolution (ALE) of Salmonella enterica in acid stress. The phenotypic and transcriptomic alterations in the acid-evolved lineages (EL) of Salmonella enterica serovar Enteritidis after 70 days of acid stress exposure were analyzed.
UNASSIGNED: The stability of phenotypic changes observed after 70 days in acetic acid was explored after stress removal using a newly developed evolutionary lineage EL5. Additionally, the impact of short-term acid stress on the previously adapted lineage EL4 was also examined.
UNASSIGNED: The results indicate that the elevated antibiotic minimum inhibitory concentration (MIC) observed after exposure to acetic acid for 70 days was lost when acid stress was removed. This phenomenon was observed against human antibiotics such as meropenem, ciprofloxacin, gentamicin, and streptomycin. The MIC of meropenem in EL4 on day 70 was 0.094 mM, which dropped to 0.032 mM when removed from acetic acid stress after day 70. However, after stress reintroduction, the MIC swiftly elevated, and within 4 days, it returned to 0.094 mM. After 20 more days of adaptation in acetic acid, the meropenem MIC increased to 0.125 mM. The other human antibiotics that were tested exhibited a similar trend. The MIC of acetic acid in EL4 on day 70 was observed to be 35 mM, which remained constant even after the removal of acetic acid stress. Readaptation of EL4 in acetic acid for 20 more days caused the acetic acid MIC to increase to 37 mM. Bacterial whole genome sequencing of EL5 revealed base substitutions in several genes involved in pathogenesis, such as the phoQ and wzc genes. Transcriptomic analysis of EL5 revealed upregulation of virulence, drug resistance, toxin-antitoxin, and iron metabolism genes. Unstable Salmonella small colony variants (SSCV) of S. Enteritidis were also observed in EL5 as compared to the wild-type unevolved S. Enteritidis.
UNASSIGNED: This study presents a comprehensive understanding of the evolution of the phenotypic, genomic, and transcriptomic changes in S. Enteritidis due to prolonged acid exposure through ALE.
UNASSIGNED: The stability of phenotypic changes observed after 70 days in acetic acid was explored after stress removal using a newly developed evolutionary lineage EL5. Additionally, the impact of short-term acid stress on the previously adapted lineage EL4 was also examined.
UNASSIGNED: The results indicate that the elevated antibiotic minimum inhibitory concentration (MIC) observed after exposure to acetic acid for 70 days was lost when acid stress was removed. This phenomenon was observed against human antibiotics such as meropenem, ciprofloxacin, gentamicin, and streptomycin. The MIC of meropenem in EL4 on day 70 was 0.094 mM, which dropped to 0.032 mM when removed from acetic acid stress after day 70. However, after stress reintroduction, the MIC swiftly elevated, and within 4 days, it returned to 0.094 mM. After 20 more days of adaptation in acetic acid, the meropenem MIC increased to 0.125 mM. The other human antibiotics that were tested exhibited a similar trend. The MIC of acetic acid in EL4 on day 70 was observed to be 35 mM, which remained constant even after the removal of acetic acid stress. Readaptation of EL4 in acetic acid for 20 more days caused the acetic acid MIC to increase to 37 mM. Bacterial whole genome sequencing of EL5 revealed base substitutions in several genes involved in pathogenesis, such as the phoQ and wzc genes. Transcriptomic analysis of EL5 revealed upregulation of virulence, drug resistance, toxin-antitoxin, and iron metabolism genes. Unstable Salmonella small colony variants (SSCV) of S. Enteritidis were also observed in EL5 as compared to the wild-type unevolved S. Enteritidis.
UNASSIGNED: This study presents a comprehensive understanding of the evolution of the phenotypic, genomic, and transcriptomic changes in S. Enteritidis due to prolonged acid exposure through ALE.
摘要：
■这项研究是由两部分组成的系列的最后一部分，该系列研究了在酸胁迫下驱动肠沙门氏菌适应性实验室进化（ALE）的分子机制。分析了酸胁迫暴露70天后肠道沙门氏菌的酸进化谱系（EL）的表型和转录组变化。
■在去除胁迫后，使用新开发的进化谱系EL5探索了在乙酸中70天后观察到的表型变化的稳定性。此外,还检查了短期酸胁迫对先前适应的谱系EL4的影响。
■结果表明，当消除酸胁迫时，在暴露于乙酸70天后观察到的升高的抗生素最低抑制浓度（MIC）消失了。观察到这种现象对人类抗生素如美罗培南，环丙沙星,庆大霉素,和链霉素.在第70天，美罗培南在EL4中的MIC为0.094mM，当在第70天后从乙酸胁迫中去除时,其降至0.032mM。然而,重新引入应力后，MIC迅速升高，4天内,它恢复到0.094mM。在乙酸中再适应20天后，美罗培南MIC增加到0.125mM。测试的其他人类抗生素表现出类似的趋势。在第70天，EL4中乙酸的MIC为35mM，即使在去除乙酸胁迫后也保持恒定。EL4在乙酸中再适应20天导致乙酸MIC增加至37mM。EL5的细菌全基因组测序揭示了与发病机理有关的几个基因中的碱基取代，如phoQ和wzc基因。EL5的转录组学分析显示毒力上调，耐药性,毒素-抗毒素，和铁代谢基因。与野生型未进化的肠炎沙门氏菌相比,在EL5中也观察到肠炎沙门氏菌的不稳定的小菌落变体(SSCV)。
■这项研究提供了对表型进化的全面理解，基因组，以及由于通过ALE长时间的酸暴露而导致的肠炎沙门氏菌的转录组变化。
■在去除胁迫后，使用新开发的进化谱系EL5探索了在乙酸中70天后观察到的表型变化的稳定性。此外,还检查了短期酸胁迫对先前适应的谱系EL4的影响。
■结果表明，当消除酸胁迫时，在暴露于乙酸70天后观察到的升高的抗生素最低抑制浓度（MIC）消失了。观察到这种现象对人类抗生素如美罗培南，环丙沙星,庆大霉素,和链霉素.在第70天，美罗培南在EL4中的MIC为0.094mM，当在第70天后从乙酸胁迫中去除时,其降至0.032mM。然而,重新引入应力后，MIC迅速升高，4天内,它恢复到0.094mM。在乙酸中再适应20天后，美罗培南MIC增加到0.125mM。测试的其他人类抗生素表现出类似的趋势。在第70天，EL4中乙酸的MIC为35mM，即使在去除乙酸胁迫后也保持恒定。EL4在乙酸中再适应20天导致乙酸MIC增加至37mM。EL5的细菌全基因组测序揭示了与发病机理有关的几个基因中的碱基取代，如phoQ和wzc基因。EL5的转录组学分析显示毒力上调，耐药性,毒素-抗毒素，和铁代谢基因。与野生型未进化的肠炎沙门氏菌相比,在EL5中也观察到肠炎沙门氏菌的不稳定的小菌落变体(SSCV)。
■这项研究提供了对表型进化的全面理解，基因组，以及由于通过ALE长时间的酸暴露而导致的肠炎沙门氏菌的转录组变化。
