| Klebsiella pneumoniae is one of the most common pathogens that cause hospital and community-acquired infections.It often causes urinary tract infections and food poisoning and other diseases.In recent years,the number of multi-drug resistant K.pneumoniae strains is increasing,and the spread of drug-resistant bacteria between humans and animals has brought harm to human health and seriously affected the development of animal husbandry.Therefore,understanding the drug resistance of K.pneumoniae and establishing a rapid,sensitive,stable and efficient molecular typing method is of great significance for guiding the rational use of antibiotics in clinical practice and the diagnosis and traceability of infectious diseases.In this study,a drug susceptibility test was performed on K.pneumoniae collected from a clinically isolated K.pneumoniae of 15 antibiotics to analyze their drug resistance.A new method for molecular typing of K.pneumoniae based on intergenic region polymorphism analysis was established and compared with the two typing methods of ERIC-PCR and MLVA.The resolution and concordance between techniques was evaluated using Adjusted Rand and Wallace coefficients.The relationship between ERIC-PCR and MLVA typing methods and the drug resistance phenotype was explored by combining the data of drug resistance and typing.The results were as follows:1.110 K.pneumoniae clinical isolates are generally multi-drug resistant,of which 36 are resistant to 14 antibiotics,accounting for 32.7%and 18 strains are resistant to 9-11 kinds of antibiotics,accounting for16.4%.Except for compound trimethoprim,these strains had the highest resistance rate to piperacillin,with a resistance rate of 76.4%.2.For the K.pneumoniae intergenic sequences with low similarity,10 pairs of primers were designed respectively,and the IRPA molecular typing method was established.66 strains of K.pneumoniae were divided into 59 genotypes with a SID value of 0.995,showing good typing ability.3.66 K.pneumoniae strains were typed by MLVA and ERIC-PCR methods,and compared with IRPA method.The results showed that 66 K.pneumoniae strains were divided into 47 and 34 genotypes by MLVA and ERIC-PCR methods,with SID values of 0.965 and 0.919,respectively,and interestingly the resolution was lower than IRPA.Clustering concordance between techniques was evaluated and the values of the adjusted Rand and Wallace coefficients were weak.There was a high congruence between IRPA and MLVA for the group composition,with68.9% of the isolates belonging to the same group.The Wallace coefficient showed that the direction consistency of IRPA and MLVA classification or group was higher than that of MLVA and IRPA classification or group.4.By combining the results of drug resistance and typing,the relationship between ERIC-PCR and MLVA typing results of 66 K.pneumoniae strains and the drug resistance phenotype was analyzed.In ERIC-PCR typing,strains 6662 and 5278 B with the same genotype and drug-resistant phenotype,strains 2005 and 7739 had the same drug-resistant phenotype,and the other genotypes had different drug-resistant phenotypes.In MLVA typing,some strains with genotypes B33,B34 and B35 had the same drug-resistant phenotype.Strains 5983 A and 5969 A were of the same type by ERIC-PCR and MLVA,but their drug resistance phenotypes were inconsistent.In general,the correlation between ERIC-PCR,MLVA and the drug-resistant phenotype was weak,and further research is needed in the future.In summary,K.pneumoniae clinical isolates have serious multi-drug resistance,and imipenem,meropenem and amikacin may be used to treat nosocomial infections caused by K.pneumoniae.Through the establishment of IRPA technology,the classification of K.pneumoniae has been successfully achieved,with high resolution and good consistency with MLVA group.This method has the advantages of rapidness,simplicity,good stability,high throughput and low cost.It is suitable to type K.pneumoniae for ordinary laboratories and provides a powerful tool for molecular epidemiology research. |
PDF Full Text Request