Submitted to: National Foundation for Infectious Disease
Publication Type: Proceedings
Publication Acceptance Date: 5/20/2004
Publication Date: 6/28/2004
Citation: Tankson, J.D., Cray, P.J., Jain, L., Haro, J.H., Ball, T.A., Gray, J., Headrick, M., Salamone, B., Anandaraman, N., Rose, B. 2004. Non-diagnostic salmonella enterica serotype newport from the animal arm of narms. National Foundation for Infectious Disease. Abstract. S3. P. 33. Interpretive Summary:
Technical Abstract: An increase in multiple resistance has been observed for Salmonella Newport isolates, heightening the public health concern. In 2000, the animal arm of the National Antimicrobial Resistance Monitoring System – Enteric Bacteria (NARMS) reported a total of 7,834 Salmonella isolates from various animal species including avian, amphibian, chicken, cattle, dairy cattle, dog, horse, iguana, reptile, swine, turkey, environmental, and snake. From these isolates, 3.6% (n = 282) were identified as Salmonella Newport, with 121 were recovered from raw product collected from federally inspected slaughter and processing plants, 62 isolates were recovered from on-farm studies, and the remaining 99 isolates were recovered from veterinary diagnostic submissions . Antimicrobial susceptibility testing was conducted using the SensitireTM semi-automated system (TREK Diagnostics) and a custom-made 96 well panel. NCCLS guidelines, where applicable, were followed for interpretation of results. Genetic relatedness of the isolates was determined by use of pulsed-field gel electrophoresis (PFGE). PCR analysis was use to detect the presence of integrons (in particular, intl1, intl2, intl3, and int4 genes) and the CMY-2 gene. Results indicated that 36 (20%) of the isolates were pan-susceptible, while only one isolate (0.55%) was resistant to one antimicrobial. One hundred forty six (80%) of the isolates were resistant to greater than or equal to 2 drugs and are referred to an multiple drug resistant (MDR). Newport was recovered from cattle (n = 168; 92%), chicken (n = 5; 3%), turkey (n = 6; 3%), and swine (n = 4; 2%) isolates. Ten grouping patterns were identified by PFGE. Homogeneity occurred within animal species while heterogeneity was observed between animal species. Banding patterns grouped according to antimicrobial susceptibility profiles. The intl1 gene occurred in 74 (40%) of the Newport isolates. None of the isolates contained intl2, intl3, or int4. One hundred twenty four (68%) of the Newport isolates contained the CMY-2 gene. These data demonstrate that non-diagnostic S. Newport isolates are not clonal and spread of Newport throughout the United States may be mediated by a transmissible plasmid.