Objective To investigate the clinical distribution characteristics of persisters isolated from the chronic infected pa-tients,so as to provide scientific basis for effective clinical measures to prevent,control and treat persister-associated chronic infection.Methods Clinical microbial samples cultured from Jan.2013 to Dec.2014 were analysed by WHONET5.6.Four bacteria species with the highest isolation rate were performed for screening of chronic infection.Concentration of bacteria were detected by viable plate count method and then the growth curve were drew of each sample under the presence of anti-biotics.Persisters were comfirmed according to the specific growth curve under the presence of antibiotics.Results Four highest isolated bacteria species of the clinical samples were Escherichia coli (1 3.2%),Klebsiella pneumoniae (9.6%), Pseudomonasaeruginosa (8%)and Staphylococcusaureus (6.6%).862 chronic infection samples were generated out of 14 216 microbial samples and 41 persisters (4 strains of Escherichia coli,23 strains of Klebsiella pneumoniae,8 strains of Pseudomonasaeruginosa and 6 strains of Staphylococcusaureus)were isolated finally.Conclusion With such a comprehen-sively retrospective analysis of the hospital clinical microbial samples,can tell that the ratio of persisters in chronic infection was not high.And chronic infections are mostly caused by gene-mutated drug-resistant bacteria.However,the isolation rate of Klebsiella pneumoniae was relatively high,of which more attention should be payed to the prevention and control.

Objective To investigate the characteristics of persisters isolated from the chronic infected patients and clarify the relationship between the infection time and persistence as well as antibiotic drugs,so as to provide scientific basis for clinical effective measures to prevent,control and treatment of persister-associated chronic infection.Methods The tolerant ability of the 41 persisters (4 strains of Escherichiacoli,23 strains of Klebsiellapneumoniae,8 strains of Pseudomonasaeruginosa and 6 strains of Staphylococcusaureus)under differet kind and concentration of antibiotics and nutritional deficiencies cindi-tions were detected.In addition,analysis of the homologous strains isolated from the same patients with different infection time was performed.Results The study found that with the increase of concentration of antibiotics,the proportion of persis-ters would gradually decrease.The tolerance ability of the same persister strain to different antibiotics was dissimilar,and different species persisters also had various tolerance ability to the same kind of antibiotics.Persisters were more able to withstand the lack of nutrition.What’s more,there is no significant difference between the resistant ability of the homolo-gous strains isolated from the same patients with different infection time (P>0.05).Conclusion Persisters have different a-bility to stand the kill of different kinds and concentration of antibiotics and they can even be completely removed when ex-posed to sufficiently high concentrations of antibiotic.