室內空氣污染物特性、所致健康影響及其控制研究─室內生物性氣膠之採樣分析技術開發(2/2)

Legionella pneumophila is an important indoor bioaerosol. The transmission root
of L. pneumophila is inhalation of contaminated aerosols. The traditional detection
method—culture is encountered several limitations. The aim of this study is to explore
the protein profile and related physiological functions at different growth stages using proteomic technique. The log culturable concentration (Log CFU/ml) of L. pneumophila was rasied from 3.94 ± 0.10 to 5.53 ± 0.24 at exponential phase, and continuously raised to 8.28 ± 0.13(48th hr) and 8.43 ± 0.14(72nd hr) at the stationary phase. The Log
CFU/ml of L. pneumophila in non-nutrient condition was declined from 8.16 ± 0.11 to 2.51 ± 0.47 at 20th day, and loss its culturability at 35th day.
In the proteomics analyze, the expressive protein numbers were gradually
increased in nutrient condition: 282 protein spots at exponential phase, followed by
early stationary phase (336 spots) and stationary phase (357 spots). However, the
protein number was decreased in non-nutrient condition. It stared with 336 spots,
declined to 290 spots at day 1st, and reduced to 258 spots and 253 spots at non-culturable day 4th and 35th. Among 99 identified proteins, an important protein—Mip (macrophage
infectivity potentiator) which is related to infection was not only found in nutrient
condition but also in non-nutrient condition. With the prolong starvation period, the
expression of Mip protein was mounting. It represented the possibility of infection for non-culturable L. pneumophila.