2 The first thing we do is macroscopic examination (by naked eyes): so we can check the color: · If it is yellow so it is normal.It could be red: this means that there is bleeding or mucus
3 · Some times it has fresh red color: this is maybe due to injury in the opening of anus (out side the bowel).· If it is black this means there is hemorrhage in the stomach. (Very important).
4 Microscopic examination It is simple way, you take glass slide, and put one drop of saline, with a stick we touch the stool and then we spread it on the slide, then we have to put a cover slip.We can use the slide to look for RBCs, WBCs, or parasites (by adding Iodine or something else).
5 We check each field and if the number of WBCs more than 10/high power field that means there is an infection. (High power field = 40X).We look for more than one field and take the average of them.
6 The bacteria that cause infections to GIT are: 1. Salmonella2. Shigella3. Helicobacter pylori4. Campylobacter jejuniAll of them cause diarrhea, so we do the culture to know which one of them is the causative agent of the infection.** E.coli is considered in adults as normal flora, but in children it is considered as pathogenic.
7 Salmonella spp.Salmonella spp. Colonies on SS Agar Show Black Discoloration, Indicative of H2S Formation.# G –ve , rod shape, facultative anaerobic.
8 Salmonella spp.IMViCKIA: K/A with H2S in between the slant and the butt.Cause food poisoningDiarrhea and typhoid fever.
9 Shigella spp. G –ve, rod shape, facultative anaerobic. IMViC : (+) + - -KIA : K/ACause shigellosis and dysentery.
10 Proteus spp. 1- Swarming: Typical Appearance of Swarming Motion ofProteus spp. on Agar Surface3 main characteristics of proteus:1- Swarming:2- Urease test +ve (the only one that has this feature)3- KIA : K/A/ H2S,
12 Staining Clostridium spp. with Shaeffer-Fulton Method Positively Stains the Endospores
13 Escherichia coliE. coli Colonies on MacConkey Agar Show Pink Discoloration, Indicative of Lactose Fermentation.
14 Escherichia coli E. coli Gives an A/A Pattern when Grown in both Kligler-Iron Agar (KIA) and Triple Sugar-Iron (TSI) Agar
15 E. coli Shows a + + - - IMViC Pattern Escherichia coliE. coli Shows a IMViC Pattern
16 Staphylococcus aureus Typical Appearance of Gram-Positive Cocci in Clusters
17 Staphylococcus aureus S. aureus Shows a Positive Coagulase Reaction
18 Vibrio choleraeLate fermentation occurred on TCBS plate representing V. cholerae
19 Campylobacter jejuniCampylobacter jejuni infection causes cramping, diarrhea, abdominal pain and fever within 2 to 5 days after a person has been exposed to the organism. Campylobacter jejuni is one of the most common bacterial causes of diarrhea.