title: Aerobactin synthesis genes iucA and iucC contribute to the pathogenicity of avian pathogenic Escherichia coli O2 strain E058.
abstract: Aerobactin genes are known to be present in virulent strains and absent from avirulent strains, but contributions of iucC and iucA, which are involved in aerobactin synthesis, to the pathogenicity of avian pathogenic Escherichia coli (APEC) have not been clarified. In this study, effects of double mutants (iucA/iutA or iucC/iutA) compared to those of single mutants (iucA, iucC or iutA) of aerobactin genes on the virulence of APEC strain E058 were examined both in vitro (aerobactin production, ingestion into HD-11 cells, survival in chicken serum) and in vivo (competitive growth against parental strain, colonization and persistence). In competitive co-infection assays, compared to the E058 parental strain, the E058ΔiucA mutant was significantly reduced in the liver, kidney, spleen (all P<0.01), heart and lung (both P<0.001). The E058ΔiutA mutant also was significantly reduced in the liver, lung, kidney (all P<0.01), heart and spleen (both P<0.001). The E058ΔiucC mutant was significantly attenuated in the heart and kidney (both P<0.05) and showed a remarkable reduction in the liver, spleen and lung (P<0.01); meanwhile, both E058ΔiucAΔiutA and E058ΔiucCΔiutA double mutants were sharply reduced as well (P<0.001). In colonization and persistence assays, compared with E058, recovered colonies of E058ΔiucA were significantly reduced from the lung, liver, spleen and kidney (P<0.01) and significantly reduced in the heart (P<0.001). E058ΔiutA was significantly reduced from the heart, lung, liver, spleen and kidney (P<0.01). E058ΔiucC, E058ΔiucAΔiutA and E058ΔiucCΔiutA were significantly decreased in all organs tested (P<0.001). These results suggest that iutA, iucA and iucC play important roles in the pathogenicity of APEC E058.
authors: Animal Infectious Disease Laboratory, Ministry of Agriculture, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.
authors: Jielu
authors: J
authors: Ling
authors: Haizhu
authors: H
authors: Pan
authors: Qingqing
authors: Q
authors: Gao
authors: Liping
authors: L
authors: Xiong
authors: Yefei
authors: Y
authors: Zhou
authors: Debao
authors: D
authors: Zhang
authors: Song
authors: S
authors: Gao
authors: Xiufan
authors: X
authors: Liu
mesh_terms: D000818:Animals; D002645:Chickens / Q000097:blood / Q000382:microbiology*; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000235:genetics / Q000382:microbiology / Q000662:veterinary*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D005816:Genetic Complementation Test; D006877:Hydroxamic Acids / Q000378:metabolism*; D011201:Poultry Diseases / Q000382:microbiology*; D013047:Specific Pathogen-Free Organisms; D014774:Virulence / Q000235:genetics
chemical_list: D006877:Hydroxamic Acids; C031819:aerobactin