| Avian pathogenic Escherichia coli(APEC)is the pathogen of Escherichia coli,which is one of the most common pathogenic bacteria in poultry infected with great harm and has caused huge economic losses to poultry industry for several years.APEC strains of serotype,therefore,to explore the virulence genes,system development group,drug resistance,and the relationship between the genetic variation,and looking for potential virulence genes and the correlation of strain resistance,statistical virulence genes and the distribution of resistance genes,grasp its popular distribution and development trends,in order to further study parts of anhui APEC pathogenic mechanism and its epidemiological studies provide the reference for the prevention and control of diseases and provide theoretical basis for clinical rational drug use.In this study,80 strains of APEC were isolated from poultry with typical pericardial liversymptoms by analyzing and identifying strains by combining morphological characteristics,culture characteristics,biochemical tests and 16S rRNA.In this study,80 strains of APEC strains were tested for virulence genes and phylogenetic analysis.The results showed that 12 of the 15 virulence genes could be detected,and each strain could carry 1 to 10 virulence genes at the same time,indicating the virulence.Genes are widely distributed in APEC strains,and synergistically cause disease by different combinations of virulence genes.Strains carrying the combination of 9 virulence genes such as papC+iutA+iss+iroN+tsh+icuD+vat+irp2+cvaC may be Increase virulence.Phylogenetic group analysis showed that group A was the dominant group with the largest number of strains,and the detection rate was higher than 50%.The purpose of this study was to explore the relationship between virulence gene quantity,phylogenetic group,serotype and virulence of APEC strains.A1(fimH?papC?iutA?iss?iroN?tsh?icuD vat?irp2?cvaC)was selected to belong to B2 virulence group and 01 serotype,and A72(fimH)belonged to A paragenetic group and non-O1,02,078 serotype.The differences between pathogenicity were compared.In this study,drug sensitivity test and drug resistance gene test were carried out on 80 APEC strains isolated from some parts of anhui province to understand the drug resistance phenotypes and genes of APEC.The results showed that the drug resistance rate of APEC to doxycycline,sulfaxazole and ampicillin was high,96.25%,92.5%and 78.75%,respectively.Among them,78 strains showed multiple drug resistance,and 82.5%of strains were resistant to 4 or more strains,indicating widespread drug resistance.Four broad categories of 12 kinds of resistant genes were detected,tetracycline class resistance gene tet(A),quinolone resistance gene parC as the current most popular resistance genes,detection rate of 72.5%and 78%respectively,sulfa drug resistance gene sul II has the highest detection rate was 56.25%,the second sul ? detection rate was 32.5%,sul I lowest detection rate of 22.5%,beta lactam enzymes ompCA drug-resistant genes of low detection rate is only 37.5%.Aminoglycoside resistance gene ant(3"),aac(3)-?,aac(6')-Ib the detection rate of 36.25%,30%and 20%respectively,dominant,and the detection rate lowest rmtB,only 3.75%,part of the resistance gene and drug resistance phenotype coincidence rate were positively correlated.This study provides valuable data for further study of drug-resistant genes and drug-resistant phenotypes,and provides reference for clinical diagnosis and drug use of APEC. |
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