Shigella

Shigella dysenteriae- Pathogenicity and Clinical Manifestation

Shigella dysenteriae- Pathogenicity and Clinical Manifestation

Shigella dysenteriae- Pathogenicity and Clinical Manifestation Shigella dysenteriae is a species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is extremely pathogenic and causes severe dysentery. Infection with this organism often leads to ulceration of the intestinal epithelium. It is known to produce an exotoxin (Shiga toxin) which disrupts protein synthesis and produces endothelial damage. Figure: … Read moreShigella dysenteriae- Pathogenicity and Clinical Manifestation

Enteroinvasive E. coli (EIEC)

Enteroinvasive E. coli (EIEC)

Enteroinvasive E. coli (EIEC) Enteroinvasive E. coli (EIEC) strains are rare in both developed and developing countries. EIEC infections are characterized by a period of watery diarrhea that precedes the onset of scanty dysenteric stools containing blood and mucus. Pathogenic strains are primarily associated with a few restricted O serotypes: O124, O143, and O164. EIEC … Read moreEnteroinvasive E. coli (EIEC)

Biochemical Test of Shigella flexneri

Biochemical Test of Shigella flexneri

Biochemical Test of Shigella flexneri ­Basic Characteristics Properties (Shigella flexneri) Catalase Positive (+ve) Citrate Negative (-ve) Gas Positive (+ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Negative (-ve) Growth in KCN Negative (-ve) H2S Negative (-ve) Indole Variable Motility Non-Motile MR (Methyl Red) Positive (+ve) Nitrate Reduction Positive (+ve) Oxidase Negative (-ve) Pigment Negative (-ve) Shape … Read moreBiochemical Test of Shigella flexneri

Laboratory Diagnosis, Treatment and Prevention of Shigella dysenteriae

Laboratory Diagnosis, Treatment and Prevention of Shigella dysenteriae

Laboratory Diagnosis of Shigella dysenteriae Specimens: stool, mucus flecks, and rectal swabs for culture. Large numbers of fecal leukocytes and some red blood cells often are seen microscopically. Microscopic examination Microscopic examination of stool smears reveals higher number of PMN cells. They are Gram negative small rod shaped, non-motile, non-capsulated. Culture and biochemical analysis The … Read moreLaboratory Diagnosis, Treatment and Prevention of Shigella dysenteriae

Habitat and Morphology of Shigella dysenteriae

Habitat and Morphology of Shigella dysenteriae

Habitat and Morphology of Shigella dysenteriae Habitat of Shigella dysenteriae They are found worldwide. Humans are only the natural host. They are also found in human intestinal tract. They are mostly found in the area where there is overcrowded. Prevalent in low waste management areas and no safe drinking water supply. Houseflies serves as vectors. … Read moreHabitat and Morphology of Shigella dysenteriae

Acetate Utilization Test- Principle, Procedure and Result Interpretation

Acetate Utilization Test- Principle, Procedure and Result Interpretation

Acetate Utilization Test- Principle, Procedure and Result Interpretation Objective of Acetate Utilization Test To differentiate organisms based on ability to use acetate as the sole source of carbon. Generally used to differentiate Shigella sp. from Escherichia coli. Principle of Acetate Utilization Test This test is used to differentiate an organism capable of using acetate as the sole source … Read moreAcetate Utilization Test- Principle, Procedure and Result Interpretation