[PFGE of Shigella flexneri 4c isolates from food-poisoning outbreaks and sporadic diarrhea patients].
OBJECTIVE
To know the molecular characteristic of Shigella flexneri 4c isolates from patients in two food-poisoning outbreaks and one sporadic diarrhea case in Hangzhou, China.


METHODS
S. flexneri isolates from patients in two food-poisoning outbreaks (outbreak 1 and outbreak 2, n = 13 and n = 12, respectively) and one sporadic diarrhea patient (n = 1) in Hangzhou during 2003 and 2005 were serotyped. Antibiotic resistances of these isolates were measured by the Kirby-Bauer method. Invasive plasmid antigen gene ipaH was examined by PCR. Pulse field gel electrophoresis (PFGE) was performed for molecular typing.


RESULTS
In outbreak 1, all 13 isolates were S. flexneri 4c, of them 6 isolates tested were quite different in PFGE patterns with dice coefficient from 0.78 to 0.92. In outbreak 2, 10 isolates were S. flexneri 4c and 2 isolates were S. flexneri X, however their PFGE patterns were almost identical (dice coefficient > 0.8). Compared to the two outbreaks isolates, the sporadic isolate was demonstrated with a distinct PFGE pattern (dice coefficient < 0.8). The antibiotic resistance patterns with 14 kinds of antibiotics had a little difference among the isolates from outbreak 1, outbreak 2 and sporadic diarrhea patient, but the same pattern was found among 10 isolates of S. flexneri 4c and 2 isolates of S. flexneri X from outbreak 2.


CONCLUSIONS
PFGE might distinguish the isolates from these two outbreaks and the sporadic diarrhea patient. Some differences in PFGE patterns, serotypes and antibiotic resistance patterns might occur among S. flexneri 4c isolates during an outbreak.
Zhang
Wei
W
Microbiology Laboratory, Hangzhou Center for Disease Control and Prevention, Hangzhou 310006, China.
Pan
Jin-Cao
JC
Meng
Dong-Mei
DM
Ye
Rong
R
Wang
Hao-Qiu
HQ
D015373:Bacterial Typing Techniques / Q000379:methods; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005517:Foodborne Diseases / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D012763:Shigella flexneri / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification*