SURVIVAL OF RIFAMPIN-RESISTANT MUTANTS OF PSEUDOMONAS-FLUORESCENS AND PSEUDOMONAS-PUTIDA IN SOIL SYSTEMS
SURVIVAL OF RIFAMPIN-RESISTANT MUTANTS OF PSEUDOMONAS-FLUORESCENS AND PSEUDOMONAS-PUTIDA IN SOIL SYSTEMS
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DOI：
10.1128/aem.54.10.2432-2438.1988
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发表时间：
1988-10-01
影响因子：
4.4
通讯作者：
LEVY, SB
中科院分区：
文献类型：
--
作者：
COMPEAU, G;ALACHI, BJ;LEVY, SB
研究了恶臭假单胞菌和荧光假单胞菌自发染色体利福平耐药突变株在无菌土壤和活体有机土壤中的去向。在无菌土培试验中，恶臭疫霉的rifr突变体与野生型亲本相比，其竞争适合度没有降低。然而，荧光假单胞菌的突变体一般分为两类。在生长速度、竞争适合度和膜蛋白组成方面，组1与野生型没有差异。组2在微量和浓缩培养基中的生长速度都较慢，并且膜蛋白图谱发生了变化。与野生型菌株相比，这些突变体的竞争适合度也有所降低。在活体土壤中，恶臭假单胞菌菌株在整个38天的试验期内持续存在，腐烂速率为每10天0.7log10CFUg土壤。第1组荧光假单胞菌突变株在接种后7~10d内保持其滴度，然后以每10d 0.2~0.4log10cfu/g土壤的速度腐烂。第二组荧光假单胞菌突变株在1-5天内保持其滴度，然后以2-3倍的速度腐烂。这些发现表明，在一些假单胞菌中，利福平耐药性可能不是一种无害的突变，在将标记菌株用作亲本菌株生存监测之前，应将其与野生型亲本进行比较。野生型或突变型菌株在无菌土壤上的定植排除了第二个添加菌株的正常定植。这些结果表明，假单胞菌在这些土壤中的定殖点有限，这一发现可能与引入生物的最终命运有关。
The fate of spontaneous chromosomal rifampin-resistant (Rifr) mutants of Pseudomonas putida and Pseudomonas fluorescens in sterile and live organic soil from which they were isolated was studied. In sterile native-soil assays, a Rifr mutant of P. putida showed no decrease in competitive fitness when compared with the wild-type parent. However, mutants of P. fluorescens were of two general categories. Group 1 showed no difference from the wild type in terms of growth rate, competitive fitness, and membrane protein composition. Group 2 showed a slower growth rate in both minimal and enriched media and an altered membrane protein profile. These mutants also demonstrated decreased competitive fitness compared with the wild-type strain. In live soil, the Rifr P. putida strain persisted throughout the 38-day test period with a decay rate of 0.7 log10 CFUg of soil per 10 days. A group 1 Rifr P. fluorescens mutant maintained its inoculated titer for 7 to 10 days and then decayed at a rate of 0.2 to 0.4 log10 CFU/g of soil per 10 days. A group 2 Rifr P. fluorescens mutant remained at its titer for 1 to 5 days before decaying at a two- to threefold-faster rate. These findings indicate that rifampin resistance may not be an innocuous mutation in some pseudomonads and that marked strains should be compared with wild-type parents before being used as monitors of parental strain survival. Colonization of sterile soil with either the wild-type or mutant strain precluded normal colonization of the second added strain. These results suggest that there are limited sites for colonization of Pseudomonas species in these soils, a finding which may relate to the eventual fate of the introduced organisms.