Genotyping and antimicrobial susceptibility of Salmonella enterica serotype Panama isolated in Taiwan.
OBJECTIVE
Previous studies have indicated that Salmonella enterica serotype Panama causes systemic infections in humans. The present study was undertaken to gain more understanding of the molecular epidemiology and antimicrobial resistance of Salmonella Panama.


METHODS
Antimicrobial susceptibility testing and molecular typing were performed on 9 clinical isolates by pulsed-field gel electrophoresis (PFGE). The presence of resistance genes, Salmonella genomic island 1 (SGI1), and integrons was examined by polymerase chain reaction. Plasmid profiles of these isolates were also determined.


RESULTS
Molecular typing showed 3 predominant PFGE types with 6 subtypes among these isolates. High rates of antimicrobial resistance to trimethoprim-sulfamethoxazole (66.7%), tetracycline (66.7%), chloramphenicol (66.7%), ampicillin (55.6%), streptomycin (55.6%), kanamycin (55.6%), and gentamicin (44.4%) were found. All 9 isolates were susceptible to ceftriaxone, cefixime, imipenem, amikacin, and ciprofloxacin. Isolates with PFGE type P1 and subtype P1-1 contained a class 1 integron and resistance genes sulI and str (p=0.048). Plasmids of 3 to 20 kb were found in all isolates belonging to PFGE type P1, subtypes P1-1 and P1-2, which were associated with multidrug resistance (p=0.012) and the resistant gene bla(TEM) (p=0.048). There was no SGI1 found in these 9 isolates.


CONCLUSIONS
In view of the high rates of drug resistance to the antimicrobial agents tested, extended-spectrum cephalosporins and fluoroquinolones seem to be a better choice for treatment of systemic infection caused by Salmonella Panama. There is a major clone (P1 and its subtypes) among the Salmonella Panama isolates. Multidrug resistance was conferred by integrons or plasmids, rather than SGI1.
Lee
Hao-Yuan
HY
Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
Yang
Yao-Jong
YJ
Su
Lin-Hui
LH
Hsu
Chih-Hao
CH
Fu
Yen-Ming
YM
Chiu
Cheng-Hsun
CH
D000890:Anti-Infective Agents / Q000494:pharmacology; D003627:Data Interpretation, Statistical; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D044404:Genomic Islands / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013624:Taiwan
D000890:Anti-Infective Agents