Fluoroquinolones Resistance And Serogroups Of Escherichia Coli From Shandong Province Of China

In clinical veterinary, Colibacillosis can cause serverse hazardous, extraordinary avian Colibacillosis. Because this disease has complex clinical symptoms and diversification of pathology characteristic, it is a common disease puzzled by cultivates estate evolutionary. For the past few years, principal disease can basic control by intensive breed, but Colibacillosis can showed the upgrade tendency and it can become one of thechief bacteriosis in cultivate estate.1. Avian E.coli were identified serotypes from Shandong province during 2003-2009 Escherichia coli isolates from diseased chickens (n = 123) and ducks (n = 91) in Shandong province of China during 2003–2009 were characterized for O serotypes, antimicrobial susceptibility and mechanisms of fluoroquinolone resistance. Fourteen serotypes were identified, the most frequent being O78 (47.6%), O35 (17.8%), O88 (7.0%), O2 (6.1%) and O18 (4.2%). Those five serotypes were occupied 82.7% in all. O3 serotype is not reported in our country.2. Avian E.coli were determinated by common drug sensitive test and MICFluoroquinolones susceptibility determinations were used by Kirby-Bauer method recommendation by WHO. The result showed that the E. coli isolates displayed resistance to Pefloxacin (92.1%), Lomefloxacin (88.8%), Ofloxacin (81.8%), Norfloxacin (79.0%), Ciprofloxacin (77.1%) and Levofloxacin (71.5%). Approximately 50% of them were resistant to all the six fluoroquinolones. Duck E.coli resistance rate was obviously higher than avian E.coii′s. The tendency of fluoroquinolones resistance in clinical isolates of E. coli has increased during 2003 to 2009 and each place has their sensitive or resistance drugs. E.coli isolated from pourlty would easy to cause resistant and usually were multidrug resistance. It supplied a basis data to secience drugs in production from this test. Minimum inhibitory consistency (MIC) was determined by the microdilution method in cation-adjudted Mueller-Hinton broth according to Clinical and Laboratory Standards Institute (CLSI) guidelines. The result showed that the E. coli isolates displayed resistance to Ciprofloxacin (87.4%) and Norfloxacin (89.3%).3. FQs gene were been cloned, sequenced and analyzed the disciplinaryAccording to Norfloxacin and Ciprofloxacin MIC, the mutations of fluoroquinolones resistance regions of gyrA, gyrB, parC and parE gene in 47 E. coli strains were tested. The important mutations leading to fluoroquinolones resistance phenotype were in the gyrA gene, Ser83→Leu and Asp87→Asn, Ser80→Ile and Glu84→Gly in parC, which indicated the fluoroquinolone-resistance determining regions mutations play an important role in contributing to the fluoroquinolones resistance of E. coli. Some other mutations such as Asp426→Asn and Ala→Thr (Ser) in gyrB gene were found, but did not have any regularity on fluoroquinolones resistance. In parE, only Ser458→Ala (Thr) locus mutation can be found, but it also did not have any regularity.