Genetic relatedness of a rarely isolated Salmonella: Salmonella enterica serotype Niakhar from NARMS animal isolates.
BACKGROUND
In the United States, Salmonella enterica serotype Niakhar is infrequently isolated. Between 1997 and 2000, the animal arm of the National Antimicrobial Resistance Monitoring System-Enteric Bacteria (NARMS) assayed a total of 22,383 Salmonella isolates from various animal sources (swine, cattle, chickens, turkeys, cats, horses, exotics and dogs) for antimicrobial susceptibility. Isolates originated from diagnostic and non-diagnostic submissions.


OBJECTIVE
To study the phenotypic and genotypic characteristics of Salmonella Niakhar.


RESULTS
Only five (0.02%) of the 22,383 isolates were identified as Salmonella Niakhar. Antimicrobial resistance testing indicated that three isolates were pan-susceptible, one isolate was resistant to ampicillin and one isolate was resistant to ampicillin, chloramphenicol, ciprofloxacin, kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline and trimethoprim/sulfamethoxazole. RAPD-PCR analysis, PFGE and ribotyping indicated that two pan-susceptible isolates were genetically similar, whereas the three remaining isolates were genetically different. The one Salmonella Niakhar isolate that was multiresistant harboured a class I integron, intI1 and two large plasmids.


CONCLUSIONS
This study represents the first report of a ciprofloxacin-resistant Salmonella isolate from the animal arm of NARMS.
Tankson
J D
JD
USDA/Agricultural Research Services, Bacterial and Epidemiology Antimicrobial Resistance Research Unit, 950 College Station Road, Athens, GA 30605, USA.
Fedorka-Cray
P J
PJ
Jackson
C R
CR
Headrick
M
M
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015139:Blotting, Southern; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D002939:Ciprofloxacin / Q000494:pharmacology; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D005838:Genotype; D008826:Microbial Sensitivity Tests; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D011159:Population Surveillance; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021521:Ribotyping; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000235:genetics* / Q000276:immunology; D012703:Serotyping
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D002939:Ciprofloxacin