Corynebacterium Diphtheriae Disease
Corynebacterium diphtheriae is a causative agent of diphtheria.It is upper respiratory tract illness and it is a contageous disease.
- It is a Gram positive, non-motile, non spore forming bacteria.
- Corynebacteria is non- capsulated slender rod.
- It shows club shaped swelling and hence called as Corynebacteria.
- Its size ranges from 3-6 μm in lenght and 0.6-0.8 μm in width.
- These cells posses metachromatic granules.
- Mode of multiplication is by binary fission.
2. Cultural characters
- Corynebacterium can grow easily on ordinary media.
- It growth is enhanced by addition of blood or serum in the media.
- It grows in a temperature range of 15° C-40° C and optimum temperature for its growth is 36° C.
- Neutral pH is optimum for its growth.
- Corynebacteria diphtheriae may be aerobic or facultative anaerobic in nature.
- They are fast growing organism.
3. Biochemical characters.
- These cells has a capacity to ferment sugars like glucose, galactose and maltose and result in acid formation but no gas.
- It is unable to ferment sugars like sucrose and lactose.
- Urea hydrolysis test is observed as negative.
- Diphtheria bacilli is a exotoxin producing organism.
- Diphtheria disease is caused due to exotoxin.
- The site of infection may be nasal, faucial, laryngeal,and genital
- These bacilli can cause circulatory failure,ulcer, hemorrhage, paralysis and diphtheria.
5. Laboratory diagnosis.
- Detection of diphtheria in initial stage is important for control of disease.
- The laboratory diagnosis include collection of samples generally swab from the lesion are collected.
- These samples are Gram stained for observation of Spirochetes.
- Toxic diphtheria are identified by immunofluorescence technique.
- These samples are isolated on blood agar.
- After incubation the culture is used for granule staining for observation of metachromatic granule.
- Virulence test such as subcutaneous test, Intracutaneous test, gel precipitation test and tissue culture technique is carried out.
- Prophylaxis means prevention of disease.
- Diphtheria can be easily controlled by immunization .
- Active, passive, combined immunizations are available for prophylaxis.
- Treatment of diphtheria include antibiotic and antitoxic therapy.
- Antibiotic such as penicillin and erythromycin are effective drug againts diphtheria.
- Antitoxin should be given as early as possible after detection of diphtheria.
8. Other pathogenic strain of Cornybacterium are-
- Cornybacterium ulcerans.
- Cornybacterium minutissimum.
- Cornybacterium hofmanni.