Spores sterility testing

Section Val. 1900 includes four aseptic processes associated with monitoring and qualification programs covering determination of components bioburden before sterilization sterility test failure investigation, bacterial endotoxin determination in WFI, in-process finished product, and monitoring the bioburden, spore bioburden, and endotoxin present on stoppers and unprocessed vials. 

Spore bioburden data are collected to screen for heat-resistant organisms. Organisms surviving heat-resistance testing are to be submitted to the terminal sterilization laboratory for D-value analysis. D-values are then compared to established models for the component sterilization process. 

Later, Timson and Short started systematic experiments to test the resistance of bacterial spores, and tried to inactivate them completely to obtain a total sterilization. These authors studied the behaviour of spores under a high-pressure treatment with a long residence time at constant pressure in a range of temperature between - 25°C and 95°C. They noted the high insensitivity to pressure of the spores compared to vegetative forms [8]. 

The relative mildew growth on polymer and on paint samples exposed to Aurobasldlum pullulans was also studied using the "Zabel Test." In this procedure, veneer strips of southern yellow pine and bass wood are sterilized, cooled, and painted (2 coats with 24 hrs. drying time). After 2-3 days the strips were soaked In distilled water, sterilized at 100 C and placed vertically In 16-ounce French square bottles containing 20 gm. of vermiculite. A mlcronutrlent enriched nutrient media was then poured Into the vermiculite (100 ml per bottle). After sterilization at 121 the painted strips were positioned so that the bottom of the painted zone was 0.5 cm above the vermiculite surface. The specimens were Inoculated with a spore suspension of Aureobasldlum pullulans (16624) by pipette. Incubated two months at 28 , and then rated visually with a 20x binocular. In the weathered series, the specimens were exposed four days In an Atlas Weather 0 Meter (UV and water spray). Representative results are summarized In Table 13. 

Spores of B. siearothermophilus ATCC 7953 (or CIP 52.81 or NCTC I(KX)7 or NCIB 81 57) or Chstridium sporogenes ATCC 7955 (or NCTC 8594 or NCIB 8053) are the recognized biological test pieces for sterilization by saturated steam. They may be purchased as spore suspensions that can be inoculated onto test pieces of one s own choosing, or as ready-made test pieces on paper or aluminum strips. An incubation temperature of 55 C should be used to test for viability after exposure. 

Initially, tests were performed to verily the best supplementary carbon source for lipase production, using the conditions described by Penha et al. [19]. The experiments were carried out in Erlenmeyer flasks (250 ml), and the fermentation medium consisted of 100 g of powdered wheat bran (60% moisture adjusted adding a 0.91% (m/v) ammonium sulfate solution, pFl=7.0) and 2% mim of vegetable oil (castor, soybean, olive, com, and palm oils). The medium was mixed and sterilized at 1.0 atm for 15 min, and afterwards, inoculated with 10 spores/g substrate. All flasks were closed and incubated in a biochemical oxygen demand (BOD) environment, keeping the moisture and ventilation conditions constant, at 32 C for 96 h. Then, the samples were analyzed to determine the glycosamine content and the lipase activity. 

A test for viable spores should be included. Where spores are found, they should be tested for thermal death kinetics and, where the result indicates a compromise of sterility, the relevant batches discarded and the applied F0 increased until the absence of spores is confirmed. 

When first produced, spores are moist, inflated cells with a relatively high rate of germination. As time passes, they dry, collapse at their centers and can not easily germinate. The probability of germinating dehydrated spores increases by soaking them in sterilized water. For 30 minutes at 15 psi, sterilize an eye dropper or similar device (syringe or pipette) and a water filled test tube or... 

In 1944, Foster et al. were one of the first groups to develop an agar diffusion test for the determination of penicillin in liquid samples. Agar seeded with Bacillus subtilis spores was added to a petri dish. Sterile glass cups were then filled with liquid samples containing different concentrations of penicillin and placed on the... 

Effectiveness of thermal sterilization may be tested by placing samples of test bacteria (Bacillus subtilis for hot air and spores of Bacillus stearothermophilus for steam sterilization) in strategic locations in the installation. After... 

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