|Mccrackin Stevenson, M|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2002
Publication Date: 10/23/2002
Citation: Sanchez, S., Mccrackin Stevenson, M.A., Jackson, C.R., Maier, M., Buffington, T., Dam, Q., Maurer, J.J. 2002. CHARACTERIZATION OF MULTI-DRUG RESISTANT ESCHERICHIA COLI ASSOCIATED WITH NOSOCOMIAL INFECTIONS IN DOGS. Journal of Clinical Microbiology. 40(10):3586-3595. Interpretive Summary: One of the great challenges facing veterinary medicine and surgery since the development of antibiotics is the development of multi-drug resistant hospital acquired infections. During the past 2 years, several dogs developed post-operative surgical wounds or lower urinary tract infections during their stay in the Veterinary Teaching Hospital at the University of Georgia. Genetic analysis revealed that several strains of bacteria were present in the hospital environment and some of these bacteria matched bacteria recovered from the ill animals. This suggested that contamination from hospital to patient occured. Hospital acquired E. coli were resistant to penicillins, cephalosporins, chloramphenicol, gentamicin, spectinomycin, sulfonamides, and tetracycline. This information will be useful for veterinarians practicing in animal hospitals and is also important in understanding how hospital acquired infections are spread. The data is also useful in the development of effective infection control programs.
Technical Abstract: Multidrug resistant opportunistic pathogens have become endemic to the veterinary hospital environment. Escherichia coli resistant to twelve antibiotics was isolated from two dogs that were admitted to the Veterinary Teaching Hospital at the University of Georgia within the span of two weeks. Review of past hospital-acquired E. coli infections revealed similar antibiotic resistance profiles characterized by resistance to most cephalosporins, B-lactams and the B-lactam inhibitor clavulanic acid as well as resistance to tetracycline, spectinomycin, sulfonamides, chloramphenicol and gentamicin. E. coli with similar resistances were also isolated from the intensive care unit and surgery ward. Multiple E. coli genetic types were endemic to the hospital environment, with pulsed-field gel electrophoresis (PFGE) fingerprint matches identified among E. coli isolates from diseased animals and the hospital environment. The extended-spectrum cephalosporin resistance in these nosocomial E. coli isolates was attributed to the cephamycinase, blaCMY2. Chloramphenicol resistance was partly due to the dissemination of the florfenicol resistance gene, flo among these isolates. Resistances encoded by both genes were self-transmissible. Although blaCMY2 and flo were common to the polyclonal, nosocomial E. coli isolates, there was considerable diversity in the genetic composition of class 1 integrons, especially among isolates belonging to the same genetic type. Two or more integrons were generally present in these isolates. The gene cassettes present within each integron ranged in size from 0.6 to 2.4 kb, although a 1.7 kb gene cassette was the most prevalent one. The 1.7 kb gene cassette contained the spectinomycin resistance gene aadA5 and the trimethoprim resistance gene dfrA17.