BacterPlate™ Haemophilus Test Agar

Ready-to-use medium on 90mm plates for testing the sensitivity of Haemophilus influenzae.
Code: 05042
Packaging: 10 plates/ box or as per customer request.
Storage Conditions: 2–8°C.
Transportation: Ambient temperature.
Shelf Life: 04 months from the date of manufacture.

INTENDED USE

BacterPlate™ Haemophilus Test Agar is recommended for susceptibility testing of Haemophilus influenzae. This medium scores over Mueller Hinton Agar with haemoglobin over clarity, thereby enabling proper visualization of inhibition zones. It also has low levels of the nucleotide thymidine, which allows testing of trimethoprim/sulphamethoxazole.
The packaging with semi-permeable Cellophane film helps balance the humidity of the environment during storage.

PRINCIPLES

BacterPlate™ Haemophilus Test Agar is a selective and enriched medium designed for the growth and antimicrobial susceptibility testing of Haemophilus species, which require hemin (X-factor), NAD (V-factor), or both. Unlike Mueller Hinton Agar, this medium includes yeast extract, HM infusion B, and acicase to meet the specific nutritional needs of Haemophilus. It also contains low levels of thymidine, enabling accurate testing with trimethoprim/sulfamethoxazole.
The medium is transparent, minimizes antimicrobial antagonism, and enhances visualization of inhibition zones due to added hemoglobin. It is recommended by the NCCLS for both dilution and disc diffusion assays.
For testing, inoculate the medium with a swab or bacterial suspension and place antimicrobial discs on the surface. Incubate in a CO₂-enriched atmosphere, then measure inhibition zones to determine susceptibility, resistance, or intermediate response based on NCCLS standards. BacterPlate™ Haemophilus Test Agar ensures reliable and accurate results for clinical and research applications.

Either streak, inoculate or surface spread the test inoculum (50 – 100 CFU) aseptically on the plate.

RESULTS

Examine the plates after 16 to 18 hours of incubation. There should be confluent growth. If only isolated colonies grow, the inoculum was too light and the test should be repeated.
Measure the diameter of the complete inhibition zone (visually assessed), including the diameter of the disc, to the nearest millimeter using calipers, rulers, or a specially prepared measuring tool for this purpose. The measurement device should be held on the back of the plate, on a non-reflective black background, and illuminated from above.
The endpoint should be considered the area with no visible growth, detectable by the naked eye. Ignore faint growth of small colonies at the edge of the clear inhibition zone. For trimethoprim and sulfonamides, traces of the antagonistic substance in the medium may allow slight growth; therefore, disregard light growth (20% or less than the growth level) and measure the more clearly defined zone to determine the diameter of the inhibition zone.
To confirm the identification of the isolated bacteria, appropriate follow-up tests should be performed.

BacterLab ensures the quality of each product batch by testing with ATCC reference strains.

Strains	Incubation Conditions	Culture results
H. influenzae ATCC 33533	Incubate at 35 – 37°C, 5 – 7% CO₂ for 18 – 24 hours	Good growth, purple colonies

For 1 liter of medium

Acid Hydrolysate of Casein	17,5 g
Meat Extract	2,0 g
Soluble starch	1,5 g
Yeast Extract	5,0 g
Agar	17,0 g
Hematin	0,015 g
Nicotinamide Adenine Dinucleotide (NAD)	0,015 g