
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Shigellosis laboratory findings
Introduction
Overview
Overview
The majority of patients with shigellosis have no significant derangements in either blood or stool work-up. Common findings include leukocytosis with left shift on blood examination, and blood and/or mucus in stools on stool examination. Multiple blood and stool cultures are needed to rule out bacteremia and to obtain antibiotic susceptibility testing, but the majority of cases yield negative cultures. Hematology, renal, and liver function testing may be required in some cases to rule out the development of any complications associated with shigellosis, such as severe dehydration, cholestatic liver disease, or hemolytic uremic syndrome (HUS).
Laboratory Findings
Laboratory Findings
Blood Examination
Hematology
- Leukocytosis with left shift is common, but leukopenia has also been reported.
- Anemia
- Thrombocytopenia
Electolytes
Blood Glucose
Inflammatory Markers
- Elevated C-reactive protein (CRP)
- Elevated erythrocyte sedimentation rate (ESR)
Renal Function
- Azotemia (elevated blood urea nitrogen)
- Elevated concentration of serum creatinine
Liver Function
- Mild elevation in bilirubin
Blood Culture
- Multiple blood cultures are usually withdrawn and may be positive for Shigella in cases complicated with bacteremia.
Stool Examination
Stool Analysis
Microscopic Evaluation
- Microscopic evidence of leukocytes on stool smear with methylene-blue stain
Stool culture
- Multiple stool cultures are needed and may be positive for Shigella in the minority of cases, especially early during the disease.
- Stool samples typically cultured using agars such as: MacConkey agar, Hektoen enteric agar, Salmonella-Shigella agar, eosin-methylene blue agar, or xylose-lysine-deoxycholate agar. Stool cultures typically demonstrate colorless colonies that do not ferment lactose.
Gallery
Gallery
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Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). [1]
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Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). [1]
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-In-Chief: Yazan Daaboul; Serge Korjian

![Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). [1]](https://www.wikidoc.org/images/2/26/Enterobacteria33.jpeg)
![Gram-negative Shigella boydii bacteria grown on a medium of sheep’s blood agar (SBA) 24hrs. From Public Health Image Library (PHIL). [1]](https://www.wikidoc.org/images/8/83/Enterobacteria32.jpeg)