MMIC Blog Post 2

Patient’s Particulars:
Name: Kwan Siew Yan
Sex: Female
Age: 29 years

Clinical Diagnosis:
Complaints: Diarrhea
Diagnosis: Entercolitis
Antibiotic Treatment: Nil

Possible organisms:
1) Vibrio species:
V. parahaemolyticus- Facultative anaerobes
Microscopic features:
· “Curved”, comma-shaped rods
· Motile with polar flagella
Laboratory investigations:
· Gram staining: Negative
· Oxidase: Positive on blood agar
· TSI: acid slant/acid deep without H2S production
· 0/129 (Vibriostat) Disk: Susceptible
· Nutrient Broth with 0% or 6-8% NaCl: Requires 1-7% NaCl
· Decarboxylase: Positive
· Culture media: TCBS as green colonies due to absence of sucrose fermentation
Antibiotic-susceptibility test:
· Tetracycline

2) Campylobacter species:
C. jejuni- Microaerophilic
Microscopic features:
· “S” shaped rods
· Darting motility
Laboratory investigations:
· Gram staining: Negative
· Oxidase: Positive
· Catalase: Positive
· TSI: Alkaline slant/alkaline deep
· Hippurate hydrolysis: Positive
· Culture media: Campylobacter agar incubated under microaerophilic conditions at 42oC as colourless or gray colonies
Antibiotic-susceptibility test:
· Erythromycin

3) Clostridium species:
C. perfringens- Obligate anaerobes
Microscopic features:
· Large, motile rods
Laboratory investigations:
· Gram staining: Positive
· Hemolysis test: Beta-hemolysis on blood agar as flat, spreading, translucent colonies
· Nagler test: Lecithinase positive
· Thioglycolate medium: Various sugars present
· Action on milk: Turned acid or digested
· Culture media: Egg yolk agar as colonies surrounded by precipitates with absence of spores
Antibiotic-susceptibility test:
· Penicillin

4) Escherichia species (Diarrheal diseases) – Facultative anaerobes
Microscopic features:
· Rod-shaped
Laboratory investigations:
· Gram staining: Negative
· TSI: Acidic slant/acidic deep with gas
· Indole: Positive
· Methyl red: Positive
· Voges-Proskauer: Negative
· Citrate: Negative
· Urease: Negative
· Culture media: EMB agar as greenish metallic sheen or MAC agar as red or pink colonies
Antibiotic-susceptibility test:
· Ampicillin

5) Salmonella species- facultative anaerobes:
Microscopic features:
· Rod-shaped
· Motile
Laboratory investigations:
· Gram staining: Negative
· TSI: Alkaline slant/acidic deep with H2S production
· Indole: Negative
· Methyl-red: Positive
· Voges-Proskauer: Negative
· Citrate: Positive
· Urease: Negative
· Culture media: EMB agar as translucent colonies or MAC agar as uncoloured colonies (non-lactose fermenting colonies)
Antibiotic-susceptibility test:
· Ampicillin

6) Shigella species- facultative anaerobes:
Microscopic features:
· Slender, rod-shaped
· Non-motile
Laboratory investigations:
· Gram staining- Negative
· TSI: Alkaline slant/acidic deep without gas or H2S production
· Indole: Negative
· Methyl-red: Positive
· Voges-Proskauer: Negative
· Citrate: Negative
· Urease: Negative
· Culture media: Culture media: EMB agar as translucent colonies or MAC agar as uncoloured colonies (non-lactose fermenting colonies)
Antibiotic-susceptibility test:
· Ampicillin

Pictures of possible organisms:
1) V. parahaemolyticus on TCBS agar


2) C. jejuni


3)Enteroinvasive E. coli (EIEC)

• EMB agar

• MAC agar

4) Salmonella species

• EMB agar

5) Shigella species

• MAC agar

References
1) http:www.yahoo.com>image search> Vibrio parahaemolyticus
2) http:www.yahoo.com>image search> Campylobacter jejuni
3) http:www.yahoo.com>image search> Enteroinvasive E. coli
4) http:www.yahoo.com>image search> Salmonella
5) http:www.yahoo.com>image search> Shigella


Tham Wan Jin June
TG02
0505073G