A Method for the Quantitative Microbiological Check of Heat Decontaminators

Niléhn, Birgitta

doi:10.3109/inf.1972.4.issue-3.12

Cited by 15 publications

(6 citation statements)

References 3 publications

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“…Whole blood (16) or Edinburgh soil (17) has been used for visual inspection and checking of blockage but cannot be quantified. Removal or destruction of Bacillus stearothermophilus spores in dried citrated blood or soil can be used as a test method (18).…”

Section: Discussionmentioning

confidence: 99%

A test for cleaning and disinfection processes in a washer‐disinfector^Note

Ransjö¹,

Engström

Håkansson

et al. 2001

APMIS

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Disinfection processes such as heat, aldehydes or alcohols kill vegetative microorganisms but do not necessarily remove other organic contamination. Organic residues impair the result of low-temperature sterilisation processes. Heat-stable organic residues may give rise to clinical symptoms in the patient. Standards are available in Britain and in Sweden for the examination of cleaning processes in washer-disinfectors. The test substances are artificial soil or blood. These standards are based on visual inspection of instruments or equipment. They cannot be used for examination of tubular instruments, nor can they be quantified. For validation of cleaning procedures a simple quantifiable method, which can be performed in an infection control laboratory is needed. We have used suspensions in horse blood of Enterococcus faecalis bacteria and Bacillus subtilis spores to test disinfection and cleaning in a washer-disinfector. Instruments used for laparoscopic surgery were contaminated with a blood bacteria suspension containing 10(7) organisms/ml and then dried and processed in a washer-disinfector using a regular process. Remaining microbial contamination was cultured quantitatively. Nineteen objects were investigated in 10 experiments each. Cleaning, measured as log reduction >5-6 of B. subtilis, was achieved on surfaces that were adequately in contact with the water flow in the machine. Disinfection (and cleaning) measured as log reduction >5-6 of E. faecalis was successful at all points examined. The test method is simple and quantifiable, and can be used to evaluate and to improve cleaning and disinfection processes.

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Section: Discussionmentioning

confidence: 99%

A test for cleaning and disinfection processes in a washer‐disinfector^Note

Ransjö¹,

Engström

Håkansson

et al. 2001

APMIS

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“…Spores were not included since they are not relevant to intestinal infection, and killing of spores is not generally required in a disinfection process. Viruses are variable in their response to heat and bacteriophage was found to be moderately resistant (Nilehn, 1972). Since the heat resistance of Str.…”

Section: Discussionmentioning

confidence: 99%

“…The evaluation of a new method (Nilehn, 1972) in which the effects of washing are excluded is reported in this paper. In the test, suspensions of organisms are sealed in lengths of heat-stable polythene tubing and applied to the surface of the bedpan.…”

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confidence: 99%

Tests of disinfection by heat in a bedpan washing machine

Ayliffe¹,

Collins²,

Deverill³

1974

J Clin Pathol

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SYNOPSIS Tests of effectiveness of disinfection of metal and polypropylene bedpans were made in a washer fitted with a steam generator. Broth cultures of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, or Streptococcus faecalis (approximately 4 x 108 organisms) were sealed in lengths of capillary tubing and attached to the surface of the pans. In other tests, pans were contaminated with an artificial soil containing Str. faecalis (0I organisms/ml). In both series of tests, counts of surviving organisms were made at the end of the washing and disinfection cycle. The tests using capillary tubes showed that the Gram-negative bacilli were effectively killed, but not necessarily Gram-positive cocci. However, when incorporated in standard soil, Str. faecalis was killed or removed during the cycle.The results indicate that the disinfection process was effective for metal bedpans, but less so for polypropylene. Possible disadvantages and modification of the machine are suggested.

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“…the ratio between the number of viable test organisms before and after the disinfecting procedure. Nilehn (1972) described an excellent method for measuring IF in which she uses a suspension of bacteriophages enclosed in polythene capillaries. According to Spri's (1977) specification, the IF should be at least 10 7 on the article to be disinfected and at least 10 5 on the inner surface of the flushing unit.…”

Section: Introductionmentioning

confidence: 99%

A method for measuring the cleaning effect of flushing disinfectors

Cederberg

Österberg

1980

J. Hyg.

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SUMMARYA method is presented with which the mechanical cleaning effect of flushing disinfectors can be estimated independently of the thermal disinfecting effect of the hot flushing water. This makes it possible to specify the demands to be placed on the disinfecting effect of flushing with water of 85°C or more.Bacillus stearothermophilus spores suspended in faeces were used as indicators because of their non-sensitivity to the hot-water temperature. Their elimination by flushing could thus be attributed to the mechanical effect of the water and not to the disinfecting effect of the temperature. A simple bacteriological technique was used, and the elimination factor (EF) was calculated as the ratio of the number of micro-organisms in the contamination before and after flushing. By using flushing water below 50°C for 130 s the EF on a bedpan was about 104-106. The effect of flushing with water of the same temperature for only half that time was somewhat weaker and when the temperature was raised to 85°C after half the flushing time the effect was somewhat stronger.It can be presumed that the conventional disinfecting phase with hot (85 'C) water for about 45 s in the commonly used flushing units could be substantially shortened and the costs of their use thereby reduced.

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A Method for the Quantitative Microbiological Check of Heat Decontaminators

Cited by 15 publications

References 3 publications

A test for cleaning and disinfection processes in a washer‐disinfector^Note

A test for cleaning and disinfection processes in a washer‐disinfector^Note

Tests of disinfection by heat in a bedpan washing machine

A method for measuring the cleaning effect of flushing disinfectors

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A Method for the Quantitative Microbiological Check of Heat Decontaminators

Cited by 15 publications

References 3 publications

A test for cleaning and disinfection processes in a washer‐disinfectorNote

A test for cleaning and disinfection processes in a washer‐disinfectorNote

Tests of disinfection by heat in a bedpan washing machine

A method for measuring the cleaning effect of flushing disinfectors

Contact Info

Product

Resources

About

A test for cleaning and disinfection processes in a washer‐disinfector^Note

A test for cleaning and disinfection processes in a washer‐disinfector^Note