title: [Investigation of Salmonella serotype Enteritidis isolates by plasmid profile analysis and pulsed field gel electrophoresis].
abstract: In this study a total of 122 Salmonella serotype Enteritidis stock strains selected from the culture collection of Enterobacteriaceae Laboratory of Ankara University Faculty of Medicine, Department of Medical Microbiology, were investigated by plasmid profile analysis with the method defined by Kado and Liu and pulsed field gel electrophoresis (PFGE) according to World Health Organization protocols using SpeI and XbaI macrorestriction enzymes, for better understanding of the molecular epidemiology of S. Enteritidis. The study strains were selected from a collection of previously isolated epidemic (n= 13) and sporadic (n= 109) strains (103 stool, 16 blood and one each bile, urine and cerebrospinal fluid) obtained from 10 different cities after the year 2000. PFGE patterns were analyzed with Gene Directory software (Syngene, UK) and a similarity index was determined by using Dice coefficient and the unweighted pair group method with mathematical averaging (UPGMA). Plasmid-carrying 110 (90%) strains that harbored 1-4 plasmids with sizes ranging from 2.0 to 100 kb were separated into patterns more than 14 (p1-p14). A total of 85 (69.7%) isolates harbored the 57 kb plasmid solely or in combination with other plasmids. By PFGE, 11 distinct patterns were shown with each enzyme SpeI and XbaI. S. Enteritidis strains after digestion with macrorestriction enzyme SpeI generated 11 different PFGE patterns (A to K), whereas XbaI generated also 11 different PFGE patterns (a to k). PFGE pattern A consisted of 93 strains (76.2%) after digestion with macrorestriction enzyme SpeI, while PFGE pattern a consisted 53 (43.4%) and PFGE pattern b 42 strains (34.4%) after digestion with macrorestriction enzyme XbaI. Using two macrorestriction enzymes two PFGE cluster profiles Aa (50 strains, 40.9%) and Ab (42 strains, 34.4%) were found to be predominating among 17 different PFGE clusters. Our results confirmed the clonal nature of S. Enteritidis strains in Turkey. The use of two enzymes in PFGE analysis appeared to increase the discriminatory power of PFGE, leading to greater diversity among strains. PFGE analysis performed by SpeI and XbaI enzymes combined with plasmid profiling could be established as a useful tool for detection of genetic relationship between isolates.
authors.affiliation: Ankara University Faculty of Medicine, Department of Medical Microbiology, Ankara, Turkey. Ebru.us@medicine.ankara.edu.tr
authors.forename: Ebru
authors.initials: E
authors.lastname: Us
authors.forename: Birsel
authors.initials: B
authors.lastname: Erdem
authors.forename: Alper
authors.initials: A
authors.lastname: Tekeli
authors.forename: Devran
authors.initials: D
authors.lastname: Gerçeker
authors.forename: Begüm
authors.initials: B
authors.lastname: Saran
authors.forename: Mehseti
authors.initials: M
authors.lastname: Bayramova
authors.forename: Fikret
authors.initials: F
authors.lastname: Sahin
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis* / Q000737:chemistry; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D006801:Humans; D010957:Plasmids / Q000145:classification* / Q000235:genetics; D012480:Salmonella Infections / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012703:Serotyping; D014421:Turkey
chemical_list: D004269:DNA, Bacterial