Characterization of a plasmid-encoded adhesin of an avian pathogenic Escherichia coli (APEC) strain isolated from a case of swollen head syndrome (SHS).
An avian pathogenic Escherichia coli (APEC) strain designated SHS4, isolated from a chicken with clinical signs of swollen head syndrome (SHS), adhered to but did not invade Hep-2 and tracheal epithelial cells. The PCR amplified fimA, csgA and tsh gene sequences. It produced Ia, Ib, E1, E3, K, and B colicins, but not colicin V and aerobactin. It harboured two plasmids of 60 and 98MDa and was resistant to streptomycin and tetracycline. Conjugation with a nalidixic acid (Na) resistant K-12 recipient strain (MS101) showed that the 98MDa plasmid did not transfer, whereas transfer of the 60MDa plasmid resulted in concomitant transfer of adhesion to Hep-2 and tracheal epithelial cells, production of the colicins Ia, E1, E3, and K, and the tsh-related DNA sequence. Transposon (TnphoA) mutagenesis of strain TR4 gave rise to strain Mut23, which lost its adhesive capacities, but was still able to express the same colicins as did strain TR4. PCR was able to amplify the tsh-related DNA sequence in this strain and a molecular probe based on transposon TnphoA indicated that the transposon was inserted in the 60MDa plasmid. Based on these results, we suggest that the 60MDa plasmid have adhesion genes, which may be responsible for the initial colonization of the upper respiratory tract of chickens.
Stehling
Eliana Guedes
EG
Department of Microbiology and Immunology, Biology Institute, CP 6109, Campinas State University, Campinas, SP, Brazil.
Yano
Tomomasa
T
Brocchi
Marcelo
M
da Silveira
Wanderley Dias
WD
D018830:Adhesins, Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D002642:Chick Embryo; D002645:Chickens; D003087:Colicins / Q000378:metabolism; D003227:Conjugation, Genetic / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics; D006388:Hemagglutinins / Q000737:chemistry / Q000235:genetics; D006801:Humans; D006877:Hydroxamic Acids / Q000378:metabolism; D016254:Mutagenesis, Insertional; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011201:Poultry Diseases / Q000382:microbiology*; D014407:Tumor Cells, Cultured
D018830:Adhesins, Escherichia coli; D001426:Bacterial Proteins; D003087:Colicins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006388:Hemagglutinins; D006877:Hydroxamic Acids; C489688:csgA protein, E coli; C063055:fimbrillin; C112027:tsh protein, E coli; D036781:Fimbriae Proteins; C077481:Crl protein, Bacteria; C031819:aerobactin