In Vivo and in Vitro Colonization Patterns of AIDA-I–Positive Escherichia Coli Isolates from Piglets with Diarrhea
| Autor: | Musangu Ngeleka, Dorothy M. Middleton, Jane Pritchard |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Diarrhea
Male 0301 basic medicine Colon 040301 veterinary sciences 030106 microbiology Fimbria medicine.disease_cause Bacterial Adhesion Cell Line Microbiology 0403 veterinary science Random Allocation 03 medical and health sciences Pathogenic Escherichia coli Escherichia coli medicine Animals Humans Colonization Intestinal Mucosa Escherichia coli Infections Swine Diseases Adhesins Escherichia coli Virulence General Veterinary Strain (chemistry) biology Biofilm 04 agricultural and veterinary sciences biology.organism_classification Microvillus Microscopy Electron medicine.anatomical_structure Animals Newborn Female Bacteria |
| Zdroj: | Journal of Veterinary Diagnostic Investigation. 16:108-115 |
| ISSN: | 1943-4936 1040-6387 |
| DOI: | 10.1177/104063870401600203 |
| Popis: | Transmission electron microscopy (TEM) was used to characterize the colonization patterns of 3 pathogenic Escherichia coli strains: PD58 and PD149 of the AIDA-I/STb/EAST1 pathotype, serogroup O: ND (not determined), and PD31 of the LT/STb/EAST1 pathotype, serogroup O149. These strains were isolated from diseased piglets and caused diarrhea in experimentally inoculated, newborn, colostrum-deprived pigs. In this study, intestinal tissues from newborn pigs experimentally infected with a high inoculum (20 ml containing 1010 cfu) were harvested and examined for bacterial colonization using light microscopy. A nonaqueous perfluorocarbon fixation method was used to preserve the glycocalyx of the microvillus border in tissues collected for TEM. Transmission electron micrographs revealed that E. coli strain PD149 displayed long flexible fimbria-like structures that intimately attached the bacteria both to the microvillus border of the upper colon and to adjacent bacteria. In vitro, this strain demonstrated the localized adherence pattern to HEp-2 cells characteristic of enteroaggregative E. coli (EAggEC). Both PD58 and PD31 strains colonized the upper colon through the formation of a biofilm, also characteristic of EAggEC. Strains PD58 and PD31 adhered poorly to HEp-2 cells in vitro, although these demonstrated a colonization pattern suggestive of diffuse and aggregative adherence, respectively. These findings suggest that strains PD58 and PD149, expressing the AIDA-I, factor and strain PD31 represents hybrid pathotypes of diarrheagenic E. coli and that they probably cause diarrhea in piglets through differing mechanisms. |
| Databáze: | OpenAIRE |
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