| Salmonella is an important food-borne pathogen that can be transmitted directly or indirectly through the digestive tract,which can cause seriously economic losses to the aquaculture industry.However,there were few reports about the resistance of Salmonella isolated from animal sources in different regions of Xinjiang to common clinical antibiotics and the classification of MLST.This study was conducted to investigate the resistance to clinical antibacterial drugs and the resistance genes in Salmonella strains derived from different animals in different regions of Xinjiang,and using the MLST method to understand the relationship between resistance strains and sensitive strains,analysis of possible mechanism of drug resistance transmission,to provide data support for guiding clinical medication and to prevent the outbreak of drug-resistant strains.In different regions of Xinjiang,samples of different animals were collected and 654 strains of Salmonella were isolated from 2,165 samples.Agar dilution method was used to determine the minimum inhibitory concentration of 13 antimicrobial agents.The results showed: ?The resistance rates of Salmonella from pets origin in Urumqi to norfloxacin,enrofloxacin,ciprofloxacin,ampicillin,amoxicillin,kanamycin,tetracycline and florfenicol were all as high as97.0%,and the majority of multidrug resistance was 8 resistance(97.4%);?The Salmonella isolates in Changji area had the highest resistance rate to amoxicillin(68.4%),ampicillin(63.2%)and florfenicol(63.2%),and it was distributed in 0-resistant to 8-resistant;?The resistant rate of Salmonella isolated from cattle to ampicillin,kanamycin and florfenicol in Yanqi area is more than50.0%,and the multidrug resistance was mainly 7 resistance(33.3%);the resistance rate of Salmonella isolated from swine to tetracycline was higher than that of other animal origin strains in the region,and it was distributed in 0-resistant to 7-resistantand.?The sensitivity of Salmonella isolates from different animal sources in Yili to 13 kinds of antimicrobial agents was over 90%.Twenty-three related resistance genes of PMQR determinants,?-lactamase genes,aminoglycoside,tetracycline class,amide alcohols and polypeptides were detected by PCR method.The results showed: ? bla TEM,bla OXA,qnr S,oqx A,oqx B,aac(6')-Ib-cr,ant(3 ")-Ia and flo R genes were detected in Salmonella from Urumqi pets,and the detection rate was as high as97.4%,the detection rate of aad A2 and tet B was 74.4% and 100%,respectively,there were 27(69.2%)Salmonella bacteria carrying bla TEM+bla OXA+qnr S+oqx A+oqx B+aac(6')-Ib-cr+aad A2+ant(3")-Ia+tet B+flo R resistance gene;?The detection rate of bla TEM(57.9%),qnr S(47.4%),ant(3 ")-Ia(52.6%),aad A2(42.1%),tet A(63.2%),tet B(47.4%)and flo R(68.4%)of Salmonella isolated from swine source in Changji area were high,there were 13 types of drug resistance coexistence.?In Yanqi area,the carrying rate of bla TEM,bla OXA,oqx A,oqx B,aac(6')-Ib-cr,ant(3")-Ia,aad A2 and tet B genes in cattle source and sheep source Salmonella were higher than that of chickens and swine source,but 4 kinds of resistance genes,such as bla CMY-2,qnr B,qnr S and tet A genes,were only detected in Salmonella from swine;?The drug resistance gene was not detected in different animal source Salmonella in Yili area.A total of 21 strains of salmonella from different animal sources in Xinjiang were selected,including 17 strains of drug-resistant bacteria and 4 strains of sensitive bacteria,and were analyzed by MLST.The results showed that the ST-type of the multidrug resistant strains in different regions and different sources was mainly ST34,the ST type of the sensitive strains in Yanqi area was ST367,the ST type of the Yili strain(not carrying the drug-resistant gene)was ST22,and the genetic relationship between them was analyzed by the evolutionary tree.It was suggested that there was a mechanism for cloning and propagation of Salmonella isolates from different animal sources in different regions of Xinjiang.The situation of Salmonella resistance in pets source of Urumqi,swine source of Changji,different animal source in Yanqi area was serious,and the multi spectral type from different animal species vary,In addition to Yili area,there are 5 kinds of related drug-resistant genes,such as ?-caprolactam,PMQR,aminoglycoside,quaternary and amide alcohols,in different animal source Salmonella.The results of MLST suggest that there is a mechanism of drug resistance in different animal sources of Salmonella in Xinjiang. |
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