Last updated on June 11th, 2021
Bacillary dysentery also known as shigellosis is a bacterial disease caused by a group of bacteria called Shigella spp. Other bacterial causes of dysentery are, Vibrio parahaemolyticus, Enteroinvasive E.coli (EIEC), Enterohemrorrhagic E.coli (EHEC), Campylobacter spps, and Salmonella sps.
Amoebic dysentery (also known as amoebiasis) is caused by a invasive protozoan parasite, Entamoeba histolytica.
| Character | Amoebic dysentery | Bacillary dysentery |
| Macroscopic | ||
| Number | 6-8 motions a day | Over 10 motions a day |
| Amount (Volume) | Relatively copious | Small amount |
| Appearance and Amount | Blood mucus, semi formed | Blood mucus, mainly watery |
| Odour | Offensive (fishy odour) | Odourless |
| Colour | Dark red (altered blood) | Bright red (fresh blood) |
| Reaction | Acidic | Alkaline |
| Consistency | Not adherent to the container | Adherent to the container |
| Microscopic | ||
| RBCs | In clumps | Discrete, sometimes in clumps due to rouleaux formation |
| Pus Cells | Few | Numerous |
| Macrophages | Few | Numerous, many of them contain RBCs hence may be mistaken for E. histolytica |
| Eosinophils | Present | Scarce |
| Charcot-Leyden (C-L) crystals* | Present | Absent |
| Pyknotic bodies** | Present | Absent |
| Ghost Cells*** | Absent | Present |
| Parasites Seen | Trophozoites of E. histolytica | Absent |
| Bacteria Seen | Many motile bacteria | Scanty, nonmotile (Shigella is non motile bacteria) |
| Culture | ||
| Growth on MacConkey Agar | Various intestinal flora may grow | Pure growth of Shigella spp. may be seen |
Further notes:
- *Charcot-Leyden crystals are hexagonal bipyramidal structures, formed from the breakdown of eosinophils and may be seen in the stool or sputum of patients with parasitic diseases.
- **Pyknotic bodies are the nuclear remains of tissue cells and leukocytes, they may present in the stools of persons suffering from amoebiasis.
- ***Ghost cell is a swollen/enlarged epithelial cell with only cytoplasmic outline but without a nucleus.
