摘要
The purpose of this study was to examine four urovirulence factors (UVFs) and their phylogenetic classes and compare their levels of resistance to antimicrobial drug classes in 159 canine uropathogenic E. coli (UPEC) isolates submitted to the Clinical bacteriology and Mycology Laboratory of The University of Tennessee Veterinary Medical Center in 2007. Multiplex polymerase chain reaction was used to detect the following UVFs: cytotoxic necrotizing factor (cnf), hemolysin (hly), S-fimbrial adhesion gene (sfa), and Pilus associated with pyelonephritis gene G allele III (pap);polymerase chain reaction was used to determine phylogenetic group. In vitro susceptibility to antimicrobial classes was evaluated, and resistance was compared to UVF presence as well as phylogenetic class. UVFs were presented in 48% of UPEC and were negatively correlated with antimicrobial resistance. Of the 159 samples, the number of UVFs expressed per isolate was 0 = 82 (52%), 1 = 24 (15%), 2 = 2 (1%), 3 = 18 (11%), and 4 = 33 (21%). The following UVFs were expressed: sfa (33%), hly (24%), cnf (25%), and pap (18%). Presence of all four UVFs, hly, cnf, and sfa together, and sfa alone, was associated with less resistance (P < 0.0001). Class B2 was the most common phylogenetic class and contained the highest number of UVFs (P < 0.001). Mean antimicrobial resistance was the highest in class A (P < 0.001) and the lowest in B2 (P < 0.001). Phylogenetic class A contained the lowest number of UVFs.
The purpose of this study was to examine four urovirulence factors (UVFs) and their phylogenetic classes and compare their levels of resistance to antimicrobial drug classes in 159 canine uropathogenic E. coli (UPEC) isolates submitted to the Clinical bacteriology and Mycology Laboratory of The University of Tennessee Veterinary Medical Center in 2007. Multiplex polymerase chain reaction was used to detect the following UVFs: cytotoxic necrotizing factor (cnf), hemolysin (hly), S-fimbrial adhesion gene (sfa), and Pilus associated with pyelonephritis gene G allele III (pap);polymerase chain reaction was used to determine phylogenetic group. In vitro susceptibility to antimicrobial classes was evaluated, and resistance was compared to UVF presence as well as phylogenetic class. UVFs were presented in 48% of UPEC and were negatively correlated with antimicrobial resistance. Of the 159 samples, the number of UVFs expressed per isolate was 0 = 82 (52%), 1 = 24 (15%), 2 = 2 (1%), 3 = 18 (11%), and 4 = 33 (21%). The following UVFs were expressed: sfa (33%), hly (24%), cnf (25%), and pap (18%). Presence of all four UVFs, hly, cnf, and sfa together, and sfa alone, was associated with less resistance (P < 0.0001). Class B2 was the most common phylogenetic class and contained the highest number of UVFs (P < 0.001). Mean antimicrobial resistance was the highest in class A (P < 0.001) and the lowest in B2 (P < 0.001). Phylogenetic class A contained the lowest number of UVFs.
