htrA、clpP基因?qū)ψ儺愭溓蚓L(zhǎng)和耐酸性影響
發(fā)布時(shí)間：2018-08-13 18:39
【摘要】：目的研究htrA. clpP基因缺失對(duì)變異鏈球菌生長(zhǎng)及耐酸性影響。 方法利用變異鏈球菌標(biāo)準(zhǔn)株及前期實(shí)驗(yàn)成功構(gòu)建的htrA單基因缺陷株、clpP單基因缺陷株及htrA-clpP雙基因缺陷株,測(cè)定4種菌株在正常培養(yǎng)條件下不同時(shí)間段的吸光度,采用MTT試驗(yàn)測(cè)定4種菌株在不同時(shí)間段的甲躦吸光度變化情況并探究其與平板活菌計(jì)數(shù)法所得的活菌量之間關(guān)系；將4種菌株培養(yǎng)至對(duì)數(shù)中期,分成兩組,一組作為實(shí)驗(yàn)組進(jìn)行5小時(shí)預(yù)酸化處理(pH=5.5),一組作為對(duì)照組在普通TPY培養(yǎng)液中進(jìn)行5小時(shí)處理,然后將兩組菌株在致死性酸環(huán)境(pH=3.0)處理3小時(shí),每隔1小時(shí)取菌液采用平板活菌計(jì)數(shù)法測(cè)定活菌數(shù),計(jì)算得到生存率,統(tǒng)計(jì)學(xué)分析。 結(jié)果1.在正常營(yíng)養(yǎng)條件下,標(biāo)準(zhǔn)株的生長(zhǎng)快于htrA、htrA-clpP缺陷株(P0.05),除3-4小時(shí)外標(biāo)準(zhǔn)株與clpP缺陷株生長(zhǎng)無(wú)明顯差異(P0.05),clpP缺陷株生長(zhǎng)快于其他兩種缺陷株(P0.05),但htrA缺陷株與htrA-clpP缺陷株生長(zhǎng)無(wú)明顯差異(P0.05)；2.未經(jīng)預(yù)酸化理4種菌株的生存率中,3小時(shí)內(nèi),標(biāo)準(zhǔn)株、htrA單基因缺陷株和clpP單基因缺陷株的生存率并無(wú)明顯差異(P0.05),而htrA-clpP雙基因缺陷株變化明顯,差異有統(tǒng)計(jì)學(xué)意義(P0.05),預(yù)酸化處理后,與標(biāo)準(zhǔn)株相比,htrA單基因缺陷株、clpP單基因缺陷株及htrA-clpP雙基因缺陷株的生存率都有下降(P0.05)；3種缺陷株相比生存率差異沒(méi)有明顯差異(P0.05),預(yù)酸化處理的標(biāo)準(zhǔn)株和htrA單基因缺陷株、htrA-clpP雙基因缺陷株生存率均明顯高于未經(jīng)預(yù)酸化處理(P0.05),預(yù)酸化處理對(duì)生存率的影響大于兩種基因缺失(P0.05)。 結(jié)論1.本實(shí)驗(yàn)中htrA、clpP缺失均可抑制變異鏈球菌的生長(zhǎng),并且雙基因缺陷對(duì)細(xì)菌生長(zhǎng)抑制作用與htrA單獨(dú)缺失相似,MTT試驗(yàn)可在一定的菌數(shù)范圍內(nèi)反映標(biāo)準(zhǔn)株與三種缺陷株的活菌數(shù)；2.與變異鏈球菌標(biāo)準(zhǔn)株相比,htrA、clpP基因單獨(dú)或同時(shí)缺失都使菌株耐酸能力有不同程度的下降。
[Abstract]:Objective to study the effect of htrA. clpP gene deletion on the growth and acid tolerance of Streptococcus mutans. Methods using the standard strain of Streptococcus mutans and the successful construction of htrA single gene deficiency strain and htrA-clpP double gene deficiency strain, the absorbance of four strains were measured under normal culture conditions. MTT test was used to determine the absorbance changes of the four strains in different time periods and to explore the relationship between them and the live bacteria quantity obtained by the method of counting live bacteria on a flat plate, and the four strains were cultured to the middle of logarithmic period and divided into two groups. One group was treated with 5-hour preacidification (pH=5.5) as experimental group, the other group was treated in normal TPY culture medium for 5 hours as control group, then the two groups were treated in lethal acid environment (pH=3.0) for 3 hours. The number of viable bacteria was determined by plate counting method every 1 hour. The survival rate was calculated and analyzed statistically. Result 1. Under normal nutrition condition, the growth of the standard strain was faster than that of the htrAgna htrA-clpP deficiency strain (P0.05). There was no significant difference between the standard strain and the clpP deficient strain except 3-4 hours (P0.05), but there was no significant difference between the htrA deficient strain and the htrA-clpP deficient strain (P0.05). 2. The survival rate of the four strains without preacidification was not significantly different from that of the standard strain within 3 hours (P0.05), but that of the htrA-clpP double gene deficient strain was significantly different from that of the standard strain (P0.05), while the survival rate of the standard strain was not significantly different from that of the htrA-clpP strain (P0.05). The difference was statistically significant (P0.05). Compared with the standard strain, the survival rate of clpP single gene deficient strain and htrA-clpP double gene deficient strain decreased after preacidification (P0.05). There was no significant difference in survival rate among the three defective strains (P0.05). The survival rates of standard strains and htrA single-gene deficient strains were significantly higher than those of non-preacidified strains (P0.05). The effect of preacidification on survival rate was significant. The noise was greater than that of two gene deletions (P0.05). Conclusion 1. In this experiment, the growth of Streptococcus mutans could be inhibited by the deletion of htrAfion clpP, and the inhibitory effect of double gene deficiency on bacteria growth was similar to that of htrA alone. MTT test could reflect the number of live bacteria of standard strain and three defective strains in a certain range. Compared with the standard strain of Streptococcus mutans, the deletion of htrAgna clpP gene alone or at the same time decreased the acid-tolerance ability of the strain to varying degrees.
【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類(lèi)號(hào)】：R378
本文編號(hào)：2181841
[Abstract]:Objective to study the effect of htrA. clpP gene deletion on the growth and acid tolerance of Streptococcus mutans. Methods using the standard strain of Streptococcus mutans and the successful construction of htrA single gene deficiency strain and htrA-clpP double gene deficiency strain, the absorbance of four strains were measured under normal culture conditions. MTT test was used to determine the absorbance changes of the four strains in different time periods and to explore the relationship between them and the live bacteria quantity obtained by the method of counting live bacteria on a flat plate, and the four strains were cultured to the middle of logarithmic period and divided into two groups. One group was treated with 5-hour preacidification (pH=5.5) as experimental group, the other group was treated in normal TPY culture medium for 5 hours as control group, then the two groups were treated in lethal acid environment (pH=3.0) for 3 hours. The number of viable bacteria was determined by plate counting method every 1 hour. The survival rate was calculated and analyzed statistically. Result 1. Under normal nutrition condition, the growth of the standard strain was faster than that of the htrAgna htrA-clpP deficiency strain (P0.05). There was no significant difference between the standard strain and the clpP deficient strain except 3-4 hours (P0.05), but there was no significant difference between the htrA deficient strain and the htrA-clpP deficient strain (P0.05). 2. The survival rate of the four strains without preacidification was not significantly different from that of the standard strain within 3 hours (P0.05), but that of the htrA-clpP double gene deficient strain was significantly different from that of the standard strain (P0.05), while the survival rate of the standard strain was not significantly different from that of the htrA-clpP strain (P0.05). The difference was statistically significant (P0.05). Compared with the standard strain, the survival rate of clpP single gene deficient strain and htrA-clpP double gene deficient strain decreased after preacidification (P0.05). There was no significant difference in survival rate among the three defective strains (P0.05). The survival rates of standard strains and htrA single-gene deficient strains were significantly higher than those of non-preacidified strains (P0.05). The effect of preacidification on survival rate was significant. The noise was greater than that of two gene deletions (P0.05). Conclusion 1. In this experiment, the growth of Streptococcus mutans could be inhibited by the deletion of htrAfion clpP, and the inhibitory effect of double gene deficiency on bacteria growth was similar to that of htrA alone. MTT test could reflect the number of live bacteria of standard strain and three defective strains in a certain range. Compared with the standard strain of Streptococcus mutans, the deletion of htrAgna clpP gene alone or at the same time decreased the acid-tolerance ability of the strain to varying degrees.
【學(xué)位授予單位】：天津醫(yī)科大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類(lèi)號(hào)】：R378
【參考文獻(xiàn)】
相關(guān)期刊論文 前4條
1 張群;胥文春;尹一兵;朱興華;李有強(qiáng);張雪梅;;clpP基因缺陷對(duì)肺炎鏈球菌毒力表達(dá)降低的研究[J];第三軍醫(yī)大學(xué)學(xué)報(bào);2009年04期
2 黃立坤;杜鵬;霍貴成;;MTT法測(cè)定乳酸菌活菌數(shù)的研究[J];食品工業(yè);2008年03期
3 張文娟;于丹妮;韓育植;任志明;;利用Cre/loxP系統(tǒng)構(gòu)建無(wú)標(biāo)記的htrA基因缺失的變鏈菌突變株[J];天津醫(yī)藥;2011年02期
4 任志明;于丹妮;韓育植;張文娟;;動(dòng)態(tài)觀察變形鏈球菌luxS基因缺陷株生物膜的形成[J];天津醫(yī)藥;2010年12期
，本文編號(hào)：2181841
本文鏈接：http://sikaile.net/xiyixuelunwen/2181841.html
最近更新
教材專(zhuān)著
