Analysis of molecular epidemiology of Chilean Salmonella enterica serotype enteritidis isolates by pulsed-field gel electrophoresis and bacteriophage typing
| Autor: | Alberto Fica, Soledad Prat, Marcela Alexandre, Hector Calfullan, Ingrid Heitmann, Alda Fernández, Germán Ebensperger, Jorge Fernández |
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| Rok vydání: | 2003 |
| Předmět: |
Microbiology (medical)
Serotype Epidemiology Salmonella enteritidis Biology Poultry Microbiology Genotype Pulsed-field gel electrophoresis Animals Humans Typing Chile Serotyping Bacteriophage Typing Phylogeny Poultry Diseases Phage typing Molecular Epidemiology Salmonella Infections Animal Molecular epidemiology Genetic Variation biology.organism_classification Virology Bacterial Typing Techniques Electrophoresis Gel Pulsed-Field Salmonella enterica Salmonella Infections Food Microbiology |
| Zdroj: | Journal of clinical microbiology. 41(4) |
| ISSN: | 0095-1137 |
| Popis: | Human Salmonella enterica serotype Enteritidis infections emerged in Chile in 1994. S. enterica serotype Enteritidis phage type 1 isolates predominated in the north, and phage type 4 isolates predominated in the central and southern regions. A study was planned to characterize this epidemic using the best discriminatory typing technique. Research involved 441 S. enterica serotype Enteritidis isolates, including clinical preepidemic samples ( n = 74; 1975 to 1993) and epidemic ( n = 199), food ( n = 72), poultry ( n = 57), and some Latin American ( n = 39) isolates. The best method was selected based on a sample of preepidemic isolates, analyzing the discriminatory power (DP) obtained by phage typing and randomly amplified polymorphic DNA and pulsed-field gel electophoresis (PFGE) analysis. The highest DP was associated with Bln I PFGE-bacteriophage typing analysis (0.993). A total of 38 Bln I patterns (B patterns) were identified before the epidemic period, 19 since 1994, and only 4 in both periods. Two major clusters were identified by phylogenetic analysis, and the predominant B patterns clustered in the same branch. Combined analysis revealed that specific B pattern-phage type combinations (subtypes) disappeared before 1994, that different genotypes associated with S. enterica serotype Enteritidis phage type 4 had been observed since 1988, and that strain diversity increased before the expansion of S. enterica serotype Enteritidis in 1994. Predominant subtype B3-phage type 4 was associated with the central and southern regions, and subtype B38-phage type 1 was associated with the north ( P < 0.0001). Food and poultry isolates matched the predominant S. enterica serotype Enteritidis subtypes, but isolates identified in neighboring countries (Peru and Bolivia) did not match S. enterica serotype Enteritidis subtypes identified in the north of Chile. The results of this work demonstrate that genetic diversity, replacement, and expansion of specific S. enterica serotype Enteritidis subtypes were associated with epidemic changes. |
| Databáze: | OpenAIRE |
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