GN Broth, 10ml fill, 16x125mm - Hardy Diagnostics - K39
GN Broth, 10ml fill, 16x125mm tube, order by the package of 20, by Hardy Diagnostics
GN Broth, 10ml fill, 16x125mm tube, order by the package of 20, by Hardy Diagnostics
GN BROTH Cat. no. K01 GN Broth, 16x100mm Tube, 6ml 20 or 100 tubes/box Cat. no. K39 GN Broth, 16x125mm Tube, 10ml 20 or 100 tubes/box INTENDED USE Hardy Diagnostics GN (Gram-Negative) Broth is recommended for the selective enrichment of Shigella and Salmonella spp. in clinical and non-clinical specimens.
SUMMARY GN Broth was originally developed by Hajna to improve the recovery of Salmonella and Shigella from clinical and non-clinical specimens. Hajna recommended specimens be enriched in GN Broth 1-6 hours prior to plating on a solid medium.(7) Hajna's formulation employed an increased amount of mannitol over dextrose. This formulation produced an accelerated growth of Salmonella and Shigella while limiting the growth of Proteus spp. and Pseudomonas aeruginosa. Inhibitory chemicals in the medium allow normal fecal flora to be maintained in a prolonged lag phase. The Shigella and Salmonella are less inhibited and enter a log or stimulated phase of growth during the first few hours of incubation. Casein and meat peptones provide amino acids and other nitrogenous substances to support bacterial growth. Dextrose and mannitol supply the energy source. The pH of the medium is maintained by phosphate buffers and osmotic equilibrium is maintained by sodium chloride. Gram-positive microorganisms and early multiplication of coliforms are both inhibited by sodium citrate and sodium deoxycholate. Direct inoculation of rectal swabs on plating media, compared to plating after 6-8 hours of incubation on GN Broth, was first reported by Craft and Miller.(9) Their results showed that more isolates of Shigella were obtained when using the GN Broth. Taylor and Schelhart reported that a greater frequency of isolation of Salmonella and Shigella was obtained when enrichment with GN Broth was used as opposed to direct plating.(8) Taylor and Harris compared various enrichment broths for their ability to support the growth of Shigella species.(10) They reported GN Broth more satisfactory than Silliker Broth, Selenite Broth or Tetrathionate Broth for propagation and recovery. FORMULA Ingredients per liter of deionized water:* Pancreatic Digest of Casein 10.0gm Peptic Digest of Animal Tissue 10.0gm Sodium Chloride 5.0gm Sodium Citrate 5.0gm Dipotassium Phosphate 4.0gm Mannitol 2.0gm Monopotassium Phosphate 1.5gm Dextrose 1.0gm Sodium Deoxycholate 0.5gm Final pH 7.0 +/- 0.3 at 25 degrees C. * Adjusted and/or supplemented as required to meet performance criteria. STORAGE AND SHELF LIFE Storage: Upon receipt store at 2-30 degrees C. away from direct light. Media should not be used if there are any signs of deterioration (shrinking, cracking, or discoloration), contamination, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing. The expiration date applies to the product in its intact packaging when stored as directed. This product has the following shelf life from the date of manufacture: 365 Days: K01 GN Broth K39 GN Broth Refer to the keyword ""Storage"", in the Hardy Diagnostics software program HUGO™, for more information on storing culture media.
PRECAUTIONS This product is for in vitro diagnostic use only and is to be used only by adequately trained and qualified laboratory personnel. Observe approved biohazard precautions and aseptic techniques. All laboratory specimens should be considered infectious and handled according to ""standard precautions"". The ""Guideline for Isolation Precautions"" is available from the Centers of Disease Control and Prevention at www.cdc.gov/ncidod/dhqp/gl_isolation.html. For additional information regarding specific precautions for the prevention of the transmission of all infectious agents from laboratory instruments and materials, and for recommendations for the management of exposure to infectious disease, refer to CLSI document M29. Sterilize all biohazard waste before disposal. Refer to the keyword ""Precautions"", in the Hardy Diagnostics software program HUGO™, for more information regarding general precautions when using culture media. Refer to the keyword ""MSDS"", in the Hardy Diagnostics software program HUGO™, for more information on handling potentially hazardous material. PROCEDURE Specimen Collection: Consult listed references for information on specimen collection.(1-4,6) Infectious material should be submitted directly to the laboratory without delay and protected from excessive heat and cold. Specimens should be delivered to the laboratory within 2-3 hours. Special attention is required for stools. They should be collected early in the course of the disease and need to be cultured within two hours after collection. Due to their delicate nature, Shigella species are best recovered by inoculating the media directly at the bedside. If there is to be a delay in processing, the specimen should be inoculated onto an appropriate transport medium and refrigerated until inoculation. Method of use: 1. Place 1.0gm of feces or 1ml of liquid stool in tube. Swab specimens may be inserted directly into the broth. 2. Emulsify the specimen thoroughly. 3. Incubate aerobically for six to eight hours at 35 degrees C. 4. Place one to two drops of the incubated broth onto selective plate media, such as MacConkey or Hektoen Enteric Agar and streak for isolated colonies. 5. Incubate aerobically at 35 degrees C. 6. Examine for pathogens in 18-24 hours.
INTERPRETATION OF RESULTS Culture analysis is made from the media to which the enriched specimen is subcultured. Consult listed references for the interpretation of growth and other identification tests to identify growth of organism in the medium to which subculture has been made.(1-6) LIMITATIONS It is recommended that biochemical and/or serological tests be performed on colonies from pure culture for complete identification. GN Broth, due to its low concentration of deoxycholate, is partially inhibitory to E. coli and other coliforms. The coliforms will eventually begin to overgrow the pathogens. Subculturing within eight hours after initial inoculation is necessary for optimal recovery of pathogens. GN Broth does not encourage the growth of Shigella dysenteriae. Refer to the keyword ""Limitations"", in the Hardy Diagnostics software program HUGO™, for more information regarding general limitations on culture media.
MATERIALS REQUIRED BUT NOT PROVIDED Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided. QUALITY CONTROL The following organisms are routinely used for testing at Hardy Diagnostics: Test Organisms Inoculation Method* Incubation Results Time Temperature Atmosphere Shigella sonnei ATCC® 9290 I 24hr 35°C Aerobic Growth Escherichia coli ATCC® 25922 I 24hr 35°C Aerobic Growth Salmonella typhimurium ATCC® 14028 I 24hr 35°C Aerobic Growth Note: GN Broth is inoculated with organism, incubated for 6-8 hours, then subcultured to MacConkey.
USER QUALITY CONTROL Check for signs of contamination and deterioration. Users of commercially prepared media may be required to perform quality control testing with at least one known organism to demonstrate growth or a positive reaction; and at least one organism to demonstrate inhibition or a negative reaction (where applicable). Refer to the following keywords, in the Hardy Diagnostics software program HUGO™, for more information on QC: ""Introduction to QC"", ""QC of Finished Product"", and ""The CLSI (NCCLS) Standard and Recommendations for User QC of Media"". Also see listed references for more information.(1-6) * Refer to the keyword ""Inoculation Procedures"", in the Hardy Diagnostics software program HUGO™, for a description of inoculation procedures. PHYSICAL APPEARANCE GN Broth should appear clear, and amber in color. REFERENCES 1. August, M.J., et al. 1990. Cumitech 3A; Quality Control and Quality Assurance Practices in Clinical Microbiology, Coordinating ed., A.S. Weissfeld. American Society for Microbiology, Washington, D.C. 2. Murray, P.R., et al. 1995. Manual of Clinical Microbiology, 6th ed. American Society for Microbiology, Washington, D.C. 3. Forbes, B.A., et al. 1998. Bailey and Scott's Diagnostic Microbiology, 10th ed. C.V. Mosby Company, St. Louis, MO. 4. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I & II. American Society for Microbiology, Washington, D.C. 5. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD. 6. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22-A2, Vol.16, No.16. 1996. Clinical Laboratory Standards Institute (CLSI - formerly NCCLS), Villanova, PA. 7. Hajna, A.A. 1955. Public Health Lab.; 13:83. 8. Taylor, W.I. and D. Schelhart. 1968. Applied Microbiology; 16:1383. 9. American Journal of Clinical Pathology; 26:411, 1956. 10. American Journal of Clinical Pathology; 44:426, 1965.