Classification '29 genera, over 100 species. Escherichia Proteus shigella Providencia edwardsiella Morganella salmonella Yersinia Citrobacter Erwinia Klebsiella Pectinobacterium Enterobacter Hafnia serratiaClassification ~29 genera, over 100 species. – Escherichia – Shigella – Edwardsiella – Salmonella – Citrobacter – Klebsiella – Enterobacter – Hafnia – Serratia – Proteus – Providencia – Morganella – Yersinia – Erwinia – Pectinobacterium