the canadian integrated program for antimicrobial resistance surveillance ( cipars ) , established in 2003 , monitors antimicrobial drug use and resistance in selected species of enteric bacteria from humans , animals , and animal - derived food sources across canada ( www.phac-aspc.gc.ca/ cipars - picra / surv - eng.php ) .
human salmonella isolates were submitted by all provincial public health laboratories in canada to the national microbiology laboratory for further characterization .
antimicrobial drug susceptibility testing was performed by using broth microdilution ( sensititer automated microbiology system ; trek diagnostic systems ltd . ,
westlake , oh , usa ) and breakpoints established by the clinical laboratory standards institute ( 4 ) .
a total of 76 s. enterica serovar kentucky isolates were submitted to the cipars program during 20032009 , and 23 ( 30% ) isolates showed ciprofloxacin resistance ( mic 4
ciprofloxacin - resistant isolates were identified from human case - patients in british columbia ( n = 2 ) , alberta ( n = 2 ) , saskatchewan ( n = 1 ) , ontario ( n = 12 ) , quebec ( n = 5 ) , and prince edward island ( n = 1 ) .
age information was available for 54 of 76 case - patients infected with s. enterica serovar kentucky during the study period .
black bars indicate ciprofloxacin - resistant isolates , and white bars indicate non  ciprofloxacin - resistant isolates . of these isolates ,
ciprofloxacin resistance was observed among case - patients 1869 years of age , and 5 of 11 were 1829 years of age .
case - patients 1829 years of age were 8 times more likely to have a ciprofloxacin - resistant strain than case - patients 5069 years of age ( odds ratio [ or ] 8.3 , 95% ci 1.03467.198 , p = 0.046 ) . of 21 ciprofloxacin - resistant isolates from case - patients who reported site of isolation , 20 were identified from feces and 1 from urine .
there were no differences in site of isolation between ciprofloxacin - resistant and ciprofloxacin - susceptible s. enterica serovar kentucky isolates .
although the total number of isolates associated with human infections was rare , of the 21,426 nontyphoidal salmonella spp .
submitted for susceptibility testing as part of the human component of the cipars program since 2003 , s. enterica serovar kentucky had a significantly higher rate of ciprofloxacin resistance than all other nontyphoidal salmonella isolates and comprised 66% ( 23/35 ; p<0.0001 ) of all ciprofloxacin - resistant isolates identified during that period . in canada , ciprofloxacin - resistant s. enterica serovar kentucky was first identified in 2005 , when 22% ( 2/9 ) of isolates submitted for drug susceptibility testing were resistant to this drug . a significant increase ( or 10.5 , 95% ci 1.1159.913 , p = 0.04 ) in the number of isolates resistant to ciprofloxacin
the largest number occurred during 20082009 , when ciprofloxacin - resistant isolates comprised 57% ( 17/30 ) of all s. enterica serovar kentucky isolates identified ( figure 1 ) .
the number of cases reported in canada is comparable with that reported in denmark over a similar period ( 3 ) .
we typed all isolates by using pulsed - field gel electrophoresis as described and restriction enzyme xbai ( 5 ) .
a dendrogram depicting the results was generated with bionumerics version 3.5 ( applied maths , sint - martens - latem , belgium ) and is shown in figure 2 .
all ciprofloxacin - resistant isolates clustered with a percentage similarity > 80% ; only 1 ciprofloxacin - susceptible isolate was found in this cluster ( figure 2 , panel a ) .
dendrograms of macrorestriction fragments of all ( a ) and ciprofloxacin - resistant ( b ) salmonella 
 enterica serovar kentucky isolates identified in canada , 20032009 . the dotted vertical line in panel
a indicates a cutoff value of 80% similarity , and the box indicates ciprofloxacin - resistant isolates .
left end and right end in panel b indicate pcr results for presence ( pos ) or absence ( neg ) of left and right junctions of salmonella genomic island 1 .
pfge , pulsed - field gel electrophoresis ; mlst , multilocus sequence typing ; ac , amoxicillin clavulanate ; am , ampicillin ; ch , chloramphenicol ; ci , ciprofloxacin ; ge , gentamicin ; na , nalidixic acid ; st , streptomycin ; su , sulfisoxazole ; te , tetracycline ; st , sequence type ; tm , trimethoprim ; pei , prince edward island .
multilocus sequence typing ( mlst ) was performed on a subset of 8 isolates on the basis of differences in pulsed - field gel electrophoresis patterns and variations in antimicrobial drug resistance .
data were submitted to the mlst database website ( http://mlst.ucc.ie/mlst/dbs/senterica ) to determine mlst types ( 6 ) .
all isolates tested were sequence type ( st ) 198 ( figure 2 , panel b ) .
this sequence type and similar antimicrobial drug resistance patterns have been recently reported in france , england and wales , denmark , belgium , and africa ( 3,7,8 ) .
many st198 multidrug - resistant isolates observed in europe and africa contained salmonella genomic island 1 ( sgi1 ) variants , particularly , sgi1-k , sgi1-q , and sgi1-p . to determine whether ciprofloxacin - resistant isolates from canada harbored similar sgi1 variants ,
we used pcr to detect the chromosomal left and right junctions of sgi1 as described ( 9,10 ) .
the right junction was found in 22 of 23 isolates , and the left junction was found in 18 of 23 isolates ( figure 2 , panel b ) .
analysis of s. enterica serovar kentucky isolates obtained during 20032009 from animal and retail meat samples as part of cipars did not identify any ciprofloxacin - resistant isolates ( www.phac-aspc.gc.ca/cipars-picra/index-eng.php ) .
this finding suggests that human infections in canada were not acquired from domestically produced food .
many ciprofloxacin - resistant s. enterica serovar kentucky human infections identified in europe have been linked to travel to countries in africa ( 3 ) . of 23 case - patients in canada
travel history was defined as previous travel out of canada within the past 7 days .
four case - patients had traveled to morocco ( 1 also had traveled to spain and portugal ) , 3 had traveled to egypt , 1 had traveled to libya , and 3 had traveled to africa ( no country reported ) .
resistance to ciprofloxacin in salmonella spp . is a growing concern because it limits the ability to treat invasive disease . in this study
, we described the characteristics of ciprofloxacin - resistant s. enterica serovar kentucky isolates in canada .
similar drug - resistance patterns and genetic backgrounds of s. enterica serovar kentucky have been observed in europe and linked to travel to countries in africa ( 3 ) . that most isolates had multidrug resistance phenotypes is of particular concern .
further studies are required to determine risk factors for acquisition of these infections in canada .
 we report emergence of ciprofloxacin - resistant salmonella enterica serovar kentucky in canada during 20032009 . 
 all isolates had similar macrorestriction patterns and were multilocus sequence type st198 , which has been observed in europe and africa . 
 ciprofloxacin - resistant s. enterica serovar kentucky represents 66% of all ciprofloxacin - resistant nontyphoidal salmonella sp . isolates observed in canada since 2003 . 