Influence Of P-Nitrophenol On Bacteria Persisters And Its Related Mechanism

Persisters were a certain proportion in bacteria group with a small subsets of phenotypic alienation,it can be tolerance lethal antimicrobial concentration by temporary dormancy or slow growing[1].Persisters was mainly through "dormant-growth-proliferation" mode to cope with adversity stress,so as to maintain their own survival and structure stability.Bacterial drug resistance phenomenon of persistence was earlier foundby Bigger in the treatment of Staphylococcus aureus infection,then in Escherichia coli,Pseudomonas aeruginosaand Mycobacterium tuberculosiswere also confirmed the existence of persisters in bacteria.Because of the bacteria persistersclosely related to repeated infection,and chronic infection treatment failure,and a long-standing of bacteria persisters increased the probability of bacteria gained foreign genes(resistance genes),so about the bacteriapersisters and their formation mechanism causedscientific workers widely concerned.First of all,this study based on explorethe influence of different organic pollutants Polybrominated Diphenyl Ether(BDE-15),Diphenyl Phosphate(BDP),Dioctyl Phthalate(DNOP),Nitrophenol(PNP),Benzopyrene(Bap),?-666(?-HCH),Naphthalene,salicylicacid in Escherichia coli and Pseudomonas aeruginosa persisters,screened out the Nitrophenol(PNP)can increased the proportion of bacteria persisters at least three orders of magnitude.PNP was one of the priority control pollutants of the U.S.environmental protection agency classification,was also an important chemical raw material,widely used in organic synthesis industry,pesticide production,medicine,powder,wood preservative and rubber and other fields,and continuously detected in the waste water,rivers,lakes,soil,air and groundwater,the Nitrophenol in waste water content was 3000-8000 mg/L,a serious threat to human health and water security,and the influence of PNP on bacteria persisters has not been reported.On the findings,ofloxacin was used in this study to determine the bacteria persisters number.First,compared the influence of PNP concentration,PNP function time and the bacterial growth period on proportion of bacteria persisters.when the PNP function bacteria logarithmic growth medium,one hour,PNP concentration for 400 mg/L had biggest influence on bacteria persisters.Then,cell self-digestion assay was performed,finding that PNP can inhibited cell self-digestion,including:increased the integrity of RNA,inhibited the protein degradation,cell size increasd 1.5 times,in E.coli,dissolved oxygen increased 2 times;in P.aeruginosa,increased 6 times,speculation may be PNP has inhibitory effect on cell respiration;Based on analysis of bacterial transcriptome and Real-time Fuorescence Quantitative Polymerase Chain Reaction(PCR),The results showed that PNP addition decreased the expression of cyoA and appC in E.coli and P.aeruginosa.Finally,through the antisense oligodeoxynucleotide inhibitory expression of cyoA,appC found that bacteria persister proportion increased compared with the original strain.