Diarrhea is one of the most frequent diseases in calves up to 30 days of age and is a major cause of economic losses. Its etiology is complex and involves the interaction of various infectious, nutritional, immunological, environmental and managerial factors. The main clinical signs are diarrhea, progressive dehydration, metabolic acidosis, electrolyte imbalance and negative energy balance with or without hypoglycemia, which if left untreated, results in death of the animal. Escherichia coli stands as an important enteropathogen involved in diarrheal syndrome. Pathogenic E. coli strains are classified into groups or pathotypes based on the production of virulence factors and on the mechanisms by which they cause diarrhea. There are five E. coli pathotypes associated with diarrhea in calves: enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), Shiga toxin - producing E. coli (STEC) and necrotoxigenic E. coli (NTEC). In this article, we present the main characteristics and an update on E. coli pathotypes causing calf diarrhea.
Pathotypes; Escherichia coli; calves; diarrhea
