Chocolate Contact Agar +LTH- ICRplus [Pack of 20]

Description

Ten contact plates each with a diameter of 55 mm triple-bagged in transparent, hydrogen peroxide impermeable sleeves. The product is gamma- irradiated in the final packaging at a dose of 9-20 kGy. The sleeves consist of polypropylene with a barrier of PE-EVOH-PE.
Further plate designs are available with the identical media formulation:
• Chocolate Agar + LTH – ICR+: 90 mm lockable settle plates, triple-bagged, gamma irradiated; intended for microbial monitoring of dry, sanitized surfaces and personnel in cleanrooms and isolators. The plate design allows aerobic, microaerophilic and anaerobic incubation.

Mode of Action

Chocolate Contact Agar is a universal blood containing culture medium for enrichment and isolation of particularly fastidious bacteria as well as yeasts and molds. This medium is suitable for detection of aerobic as well as anaerobic microorganisms. This medium is characterized by a rich nutritive basis. Dextrose is the source of carbon and energy. In addition the growth supplements haemin and NAD are released from the sheep blood erythrocytes during heating. These components as well as further added growth supplements allow good growth conditions of fastidious aerobic and anaerobic microorganisms.

The medium is supplemented with pyruvate in order to provide an efficient neutralization of hydrogen peroxide for use in isolators. Internal studies confirmed the neutralization efficiency of the neutralizers lecithin, polysorbate
(Tween®) 80 and histidine for disinfectants containing the following active agents (based on tests with TSA plates + LT):
• Alcohol (70 % ethanol or isopropyl alcohol)
• Dichloroisocyanurate
• Glucoprotamine
• Hydrogen Peroxide

• Peracetic acid
• Low concentrated quaternary ammonium compounds

The neutralizing efficiency towards residues of disinfectants in use should be validated at the application site. For neutralization of high concentrated quaternary ammonium compounds and/or polyhexamethylene biguanides the use of Neutralizer A Contact Plates is recommended. The formulation provides good growth promoting properties even for fastidious and anaerobic
microorganisms:

For a number of anaerobic microorganisms an incubation temperature of 37°C is preferable. They grow faster and colony sizes are bigger compared to lower incubation temperatures of 30°C. The following anaerobic test strains were tested for recovery rates and colony diameter at different incubation temperatures using Chocoloate Agar – ICR + in settles plates “VENT”-position compared to Columbia Blood Agar. Due to included slow growing microorganisms such as Propionibacterium acnes the minimum incubation time was set to 5 days.

Typical Composition
Peptone 13 g/l
Yeast Extract 5 g/l
Meat Extract 2 g/l
NaCl 5 g/l
Dextrose 2 g/l
K2HPO4 2.5 g/l

Polysorbate (Tween®) 80 5 ml/l
Lecithin 0.7 g/l
Histidine 0.5 g/l
Sheep Blood 50 ml/l
Agar 15 g/l

Growth Supplements

The appearance of the medium is chocolate brown, non-transparent. The pH value is in the range of 7.1-7.5. The medium can be adjusted and/or supplemented according to the performance criteria required.

Application and Interpretation
The plates are introduced into cleanrooms grade A or B by removing one bag in each material lock. For use in isolators the inner bag has a hole in the sealing to hang up the bag during decontamination. Do not leave plates which are unprotected (unwrapped) in an isolator during decontamination.

Each plate is provided with a label including a data matrix code for paperless plate identification. The code consists of a two-dimensional 20-digit serial number, which harbors the following information:
digits 1-3: here code 835 (corresponds to article 146555); digits 4-9: lot number; digits 10-14: batch specific individual number; digits 15-20: expiration date (YY/MM/DD).

Please check each agar plate before using it on sterility and pay attention to aseptic handling in order to avoid false positive results.
According to ISO 14698 the plates are opened and the agar surface is pressed on the dry surface to be tested for some seconds with a steady pressure. Similar recommendations are included in the PDA technical report No.13. Afterwards the plates are closed and transferred to an incubator. To protect the plates from secondary contamination during transport and incubation outside of the cleanroom zone, sterile transport bags  may be used. Residues of culture medium should be removed from the surface after sampling.

In addition, the plate model (plus or „+“) is supplied with a lockable lid. For safe transport after sampling without the risk of losing the lid as well as for aerobic incubation the plates should be locked in the “CLOSED”-position (turn the lid clockwise). For anaerobic or microaerophilic incubation in the “VENT”- position (turn the lid counter-clockwise) is mandatory, because this lid-position provides sufficient gas exchange with the atmosphere in the incubation chamber. Aerobic incubation while turning the lid in “VENT”-position is also possible, but may increase the desiccation of the agar plates during incubation. Several recommendations are given by different guidelines for incubation: according to USP <1116> the plates used for environmental monitoring should be incubated between 20 and 35 °C for not less than 72 hours.

According to the FDA Aseptic Guide the plates for determination of the total aerobic bacterial count should be incubated at 30 to 35 °C for 48 to 72 hours, while the plates for determination of the total yeast and mold count should be incubated at 20 to 25 °C for 5 to 7 days. Individual incubation conditions can be chosen and should be validated at the application side.

Finally the number of CFU per plate is examined. Grown colonies are recommended to be identified. Media, which contain ingredients of animal or human origin such as blood, meat extract or animal tissues, have to be considered potentially infectious. After contact of such media a disinfection of the affected skin area is recommended.

Storage and Shelf Life

The product can be used for sampling until the expiry date if stored upright, protected from light and properly sealed at +15 °C to +25 °C. Condensation can be prevented by avoiding quick temperature shifts and mechanical stress. The testing procedures as described on the CoA can be started up to the expiry date printed on the label.

Disposal

Please mind the respective regulations for the disposal of used culture medium (e.g. autoclave for 20 min at 121 °C, disinfect, incinerate etc.).