Molecular epidemiology and genetic environment of acquired bla ACC-1 in Salmonella enterica serotype Livingstone causing a large nosocomial outbreak in Tunisia.
Eighty-four isolates of Salmonella enterica serovar Livingstone were collected from patients hospitalized in a pediatric ward in Sfax Hospital (South Tunisia). These isolates were responsible for two nosocomial outbreaks in 2000 and 2002. Twenty-eight clinical isolates of S. enterica serovar Livingstone were also obtained in two other Tunisian hospitals in Monastir (Central Tunisia) and Tunis (North Tunisia), respectively, in 2002 and 2003. Pulsed-field gel electrophoresis yielded that these isolates were closely related. Antimicrobial susceptibility testing showed a particular beta-lactam resistance phenotype, suggestive of the presence of an AmpC-type enzyme in 111 of the 112 clinical isolates. bla(ACC-1) was characterized by polymerase chain reaction (PCR) and sequence analysis in the 111 isolates. TEM-1 was characterized in all strains and SHV-2a in only two strains. The genetic organization of bla(ACC-1) was determined by PCR mapping and sequencing. The plasmid-borne bla(ACC-1) gene mapped immediately downstream from ISEcp1. This ISEcp1 insertion sequence was itself disrupted by IS26 insertion sequences. A supplementary deletion of 13 bp was observed in ISEcp1 upstream IS26, in all isolates from Tunis, except one. PCR analysis and sequencing also revealed the presence of tnpR, bla(SCO-1), gdha, IS1353, and TniB Delta 1.
Laboratory of Microbiology, University Hospital Center (CHU) of Habib Bourguiba, Sfax, Tunisia.
Sonia
S
Ktari
Guillaume
G
Arlet
Charlotte
C
Verdet
Samir
S
Jaoua
Amel
A
Kachrid
Saida
S
Ben Redjeb
Fouzia
F
Mahjoubi-Rhimi
Adnane
A
Hammami
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D014416:Tunisia / Q000453:epidemiology; D018440:beta-Lactam Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases