Protein expression in Streptococcus mutans biofilm cells during acid adaptation in the presence of fluoride
2017 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [sv]
Streptoccocus mutans är en vanlig förekommande munhålebakterie som ofta beskrivs som acidogen och acidurisk, då den både kan producera syra och utveckla syratolerans vid låga pH. Dessa egenskaper fyller en viktig funktion vid utveckling av karies. Daglig tillförsel av fluor har visat sig ha en förebyggande effekt mot karies, inte bara genom att stärka hydroxyapatiten i emaljen utan även genom inverkan på bakteriernas metabolism. Syftet med denna studie är att undersöka S. mutans proteinuttryck under syraadaptering i närvaro av fluor. I denna studie studerades två timmar gamla biofilmceller av S. mutans UA159 som exponerades för pH 5,5 i närvaro och frånvaro av fluor, med en koncentration motsvarande fluorlack. De intracellulära proteinerna extraherades och separerades sedan genom 2D gelelektrofores innan de analyserades i bildanalysprogrammet PDQuest. Resultaten visade på totalt elva förändringar där skillnaden i proteinuttryck var minst dubbelt så stor hos bakterier som utsatts för fluor jämfört med kontrollen. Av dessa var fem nedreglerade och sex uppreglerade. Bland dessa återfanns HPr, S1P, enolas, TPI, GroEL and GroES. Detta indikerar att fluor påverkar både proteiner involverade i glykolysen och i proteinsyntesen. Det ökade uttrycket av proteiner involverade i ATP-producerande reaktioner i glykolysen och pyruvatkonverteringen indikerar ett ökat behov av ATP, som skulle kunna användas för att stödja de protonpumpande ATPaser som upprätthåller det intracellulära pH-homeostasen.
Abstract [en]
Streptoccocus mutans is a common oral bacteria, frequently described as acidogenic and aciduric, as it can both produce acid and develop acid tolerance at low pH. These characteristics play an important role in the development of caries. Daily administration of fluoride has been shown to have a preventive effect against caries, not only by strengthening the hydroxyapatite in the enamel but also, the impact on the metabolism of the bacteria. The aim of this study was to investigate the S. mutans protein expression during acid adaptation in the presence of fluoride. In this study 2-hour biofilm cells of S. mutans UA159 were exposed to pH 5.5 in the presence and absence of fluoride with a concentration corresponding fluoride varnish. The intracellular proteins were extracted and then separated by 2D gel electrophoresis before being analysed in an image analysis software PDQuest. The results showed a total of eleven changes where the difference in protein expression were at least 2-fold in bacteria exposed to fluoride compared to the control. Of these, five were downregulated and six were upregulated. These included HPr, S1P, enolase, TPI, GroEL and GroES. This shows that fluoride affects both proteins involved in glycolysis and in protein synthesis. The increased expression of proteins involved in ATP producing reactions of the glycolytic pathway and pyruvate conversion indicate an increased need for ATP that could be used to support the proton pumping ATPases in maintaining intracellular pH homeostasis.
Place, publisher, year, edition, pages
Malmö högskola/Odontologiska fakulteten , 2017. , p. 21
Keywords [en]
Streptoccocus mutans, fluoride, acid tolerance, protein expression
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:mau:diva-19810Local ID: 22661OAI: oai:DiVA.org:mau-19810DiVA, id: diva2:1479655
Educational program
OD Tandläkarutbildning
2020-10-272020-10-272022-06-27Bibliographically approved