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United States Department of Agriculture

Agricultural Research Service

Title: Detection of Class I Integron and Marrab Operon in Multiple Drug Resistant Salmonella Enterica Serotype Niakhar

Authors
item Tankson, Jeanetta
item Cray, Paula
item Jackson, Charlene
item Gray, Jeffrey
item Barrett, John
item Headrick, Marcia - FDA - CVM

Submitted to: National Foundation for Infectious Disease
Publication Type: Proceedings
Publication Acceptance Date: May 10, 2002
Publication Date: June 27, 2002
Citation: Tankson, J.D., Cray, P.J., Jackson, C.R., Gray, J.T., Barrett, J.B., Headrick, M. 2002. DETECTION OF CLASS I INTEGRON AND MARRAB OPERON IN MULTIPLE DRUG RESISTANT SALMONELLA ENTERICA SEROTYPE NIAKHAR. National Foundation for Infectious Disease. P.37 S-10.

Technical Abstract: In the United States, Salmonella enterica serotype Niakhar is not frequently isolated. Between 1997 and 2000, the animal arm of the National Antimicrobial Resistance Monitoring System - Enteric Bacteria (NARMS) at USDA-ARS in Athens, GA assayed for antimicrobial resistance a total of 22,383 Salmonella isolates from swine, cattle, chickens, turkeys, exotics, horses, cats, and dogs. Only 5 (0.02%) of these isolates were identified as Niakhar (designated A-E). Of the five, 3 (B - D) were isolated in the Midwest, while A and E were isolated in the Southern United States. Antimicrobial resistance testing indicated that isolates A, B, and E were susceptible to all antimicrobials tested; whereas isolate C was only resistant to one antimicrobial. However, isolate D had resistance to nine antimicrobials. Class I integrons (intI1) in Salmonella are known to harbor multiple resistance genes. Using PCR primers to intI1, a 568-bp fragment was amplified from isolate D. None of the other isolates harbored Class I to Class 4 integrons (intI1, intI2, intI3, and int4) in their genomic DNA. Some Salmonella species are also known to harbor intrinsic mechanisms of resistance such as a multiple antibiotic resistance operon (marRAB). Using PCR primers to marRAB, a 2.3-kb and 0.4-kb fragment was amplified from isolate D (a multi-resistant isolate), and not isolates A and B (isolates susceptible to all antimicrobials tested). This is a first report of a marRAB operon in Salmonella Niakhar.

Last Modified: 7/24/2014