Distribution and characterization of class 1 integrons in Salmonella enterica serotype Gallinarum biotype Gallinarum.
Fowl typhoid caused by Salmonella enterica subsp. enterica serotype Gallinarum biotype Gallinarum is the most important chicken disease in Korea. Due to appearance of new or multiple antibiotics resistances in the recently isolated strains, it was difficult to control the disease using antibiotics in our country. Therefore, the prevalence and genetic contents of class 1 integrons in biotype Gallinarum isolated between 1992 and 2001 were investigated by PCR and direct sequencing, respectively. Out of 90 strains, 35 (39%) carried class 1 integrons. The 1.0, 1.6 and 2.0kbp amplicons were amplified in 32 strains (36%), 2 strains (2%) and 1 strain (1%), respectively. The 1.0, 1.6 and 2.0 kbp amplicons contained one (aadA1a), two (aadB-aadA1b) and three cassettes (dhfrXII-orfF-aadA2), respectively, providing resistances against aminoglycosides (aadA1a, aadA1b, aadB, and aadA2) and trimethoprim (dhfrXII). The integron-carrying strains of biotype Gallinarum appeared in 1996 and acquired additional cassettes in 2000. Although the resistances to ampicillin, tetracycline and chloramphenicol are unrelated to class 1 integrons, relatively high prevalence of integron in biotype Gallinarum may be a dormant threat to the chemotherapy of the disease in the near future because of potency to acquire additional antibiotics resistances.
Kwon
Hyuk Joon
HJ
Institute of iNtRON Biotechnology, Seoul, 138-200, South Korea.
Kim
Tae Eun
TE
Cho
Sun Hee
SH
Seol
Jae Goo
JG
Kim
Bum Joon
BJ
Hyun
Jin Won
JW
Park
Kyoung Yoon
KY
Kim
Sun Joong
SJ
Yoo
Han Sang
HS
D000818:Animals; D002645:Chickens; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D032023:Integrons / Q000235:genetics*; D007723:Korea; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011201:Poultry Diseases / Q000188:drug therapy / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000188:drug therapy / Q000382:microbiology*; D019779:Salmonella enterica / Q000235:genetics / Q000254:growth & development*; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial