Sterilization practice

Use standard sterilization practices prior to administering injections, suturing, or other practices that puncture or break the skin. 

Choose healthy plants. Inspect new plants refore introducing them to your yard or garden. Look for signs of disease and insects, and reject any that look suspicious. If available, buy certified disease-free plants and seeds. Inquire about seed sterilization practices at your seed source. Buy from suppliers that use sanitation procedures and heat-sterilizing techniques instead of synthetic chemicals to control disease on nursery stock and seeds. 

Theory without experience is sterile, practice without theory is hlind. 

It is necessary to estabUsh a criterion for microbial death when considering a sterilization process. With respect to the individual cell, the irreversible cessation of all vital functions such as growth, reproduction, and in the case of vimses, inabiUty to attach and infect, is a most suitable criterion. On a practical level, it is necessary to estabUsh test criteria that permit a conclusion without having to observe individual microbial cells. The failure to reproduce in a suitable medium after incubation at optimum conditions for some acceptable time period is traditionally accepted as satisfactory proof of microbial death and, consequentiy, stetihty. The appHcation of such a testing method is, for practical purposes, however, not considered possible. The cultured article caimot be retrieved for subsequent use and the size of many items totally precludes practical culturing techniques. In order to design acceptable test procedures, the kinetics and thermodynamics of the sterilization process must be understood. 

Working areas within certain industrial buildings may have restricted access (i.e. sterile laboratories, radioactive areas). Separate toilet accommodation may be required in these areas, an assessment of which may be obtained from the operator and reference to such publications as Atomic Energy Code of Practice, Laboratory Practice. It may also be necessary to operate such appliances remotely by photoelectric cell, sonic control or foot control. 

All of the above processes are operated as batch fermentations, in which a volume of sterile medium in a vessel is inoculated. The broth is fermented for a defined period. The tank is then emptied and the products are separated to obtain the antibiotic. The vessel is then recharged for batch operation with medium and the sequence repeated, as often as required. Continuous fermentation is not common practice in the antibiotics industry. The antibiotic concentration will rarely exceed 20gT 1 and may be as low as 0.5g-l 1. 

Ayliffe G.A.J., Coates D. Hofifinan P.N. (1993) Chemical Disinfection in Hospitals. London PHLS. British Medical Association (1989) Code of Practice for Sterilization of Instruments and Control of Cross Infection. London BMA (Board of Science and Education). 

Russell A.D., Hugo W.B. Ayliffe G.A.J, (ed.) (1998) Principles and Practice of Disinfection, Preservation and Sterilization, 3rd edn. Oxford Blackwell Science. 

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