SANITARY INDEX ORGANISM
Introduction:
Maintaining sanitation and hygiene is crucial in various fields, including food
safety, water quality monitoring, and public health. Sanitary index organisms
play a vital role in assessing the effectiveness of sanitation practices and
identifying potential contamination risks. Sanitary index organisms are a
specific group of microorganisms that are used as indicators of the overall
cleanliness and hygiene of a particular environment, such as water, food, or
surfaces. Their presence or absence can provide valuable information about the
potential presence of harmful pathogens, even though they themselves may not
be harmful. The term ‘indicator organisms’ has been used for nearly a century to
assess the microbiological status of food production and food control systems,
including evaluating the quality or safety of raw or processed food products and
validating the effectiveness of microbial control measures.
History:
Indicator organisms were first used in the testing of water supplies for sanitary
quality. The mid to late 1800s were marked by huge developments in the
sciences of public health and microbiology. The accomplishment list included
the recognition by William Budd in 1859 that typhoid fever, an important
waterborne disease throughout human history, was spread by infective material
in feces, and that the disease could be prevented by avoiding fecal
contamination of water supplies.
Later, the germ theory of disease and the development of microbiological pure
culture methods set the stage for the isolation of Salmonella typhi and its
identification as the causative agent of typhoid fever (1880, Karl Eberth). In
1885, Theodor Escherichia isolated Bacterium coli (later, Escherichia coli) from
feces and noted it to be a natural inhabitant of the human intestine.
The nearly ubiquitous existence of E. coli in human feces was soon recognized,
and it was not long before the idea was proposed that E. coli could be used to
indicate that a water supply was contaminated with feces (1892, Franz
Schardinger).
Methods for identification of E. coli were not as easy in the late 1800s as
they are today. Other organisms that often existed in association with E.
coli were like it in many respects but could be distinguished by certain
physiological traits. Because of them
similarity, E. coli and these close relatives were termed “coliforms.” Testing for
the coliform group was simple, compared with E. coli. Microbiologists began to
regard coliforms as a testing alternative for E. coli and therefore, as indicators
, of fecal pollution. In 1914, the U.S. Public Health Service (PHS) adopted
coliform testing as a means of ensuring the sanitary nature of drinking water
supplies.
At that time, nearly a quarter of all food- and waterborne illness outbreaks were
caused by milk. The Pasteurized Milk Ordinance was developed by the PHS in
1924 as a measure to prevent milkborne disease. In addition to pasteurization
standards and recommendations for sanitary production, the Ordinance
included coliform testing of the pasteurized milk. Also in that year, a multistate
outbreak of typhoid was traced to consumption of oysters harvested from
sewage-polluted waters. The National Shellfish Sanitation Program swiftly
followed in 1925, and among the recommendations to enhance consumer safety
was coliform testing of shellfish growing areas and harvested products.
Criteria for an Ideal Indicator Organism:
∙ The organism should be useful for all types of water.
∙ The organism should be present whenever enteric pathogens are present.
∙ The organism should have a reasonably longer survival time than the
hardiest enteric pathogen.
∙ The organism should not grow in water.
∙ The testing method should be easy to perform.
∙ The density of the indicator organism should have some direct
relationship to the degree of fecal pollution.
∙ The organism should be a member of the intestinal microflora of
warm-blooded animals.
Commonly Used Indicator Organisms:
Many different types of indicators have been advocated for use in
particular applications; however, this minireview is limited to the most
common indicators used for foods and drinking water, i.e., the aerobic
plate count; coliforms; E. coli; Enterobacteriaceae; Listeria spp.; and the
yeasts and molds. Microbial groups which may have use as indicators in
certain applications, e.g., enterococci, Staphylococcus, endospore-formers,
lactic acid bacteria, and others, have not been included in this discussion,
nor have cellular components, products or nonorganismal agents, e.g.,
ATP, phosphatase, endotoxin, coliphages.
Introduction:
Maintaining sanitation and hygiene is crucial in various fields, including food
safety, water quality monitoring, and public health. Sanitary index organisms
play a vital role in assessing the effectiveness of sanitation practices and
identifying potential contamination risks. Sanitary index organisms are a
specific group of microorganisms that are used as indicators of the overall
cleanliness and hygiene of a particular environment, such as water, food, or
surfaces. Their presence or absence can provide valuable information about the
potential presence of harmful pathogens, even though they themselves may not
be harmful. The term ‘indicator organisms’ has been used for nearly a century to
assess the microbiological status of food production and food control systems,
including evaluating the quality or safety of raw or processed food products and
validating the effectiveness of microbial control measures.
History:
Indicator organisms were first used in the testing of water supplies for sanitary
quality. The mid to late 1800s were marked by huge developments in the
sciences of public health and microbiology. The accomplishment list included
the recognition by William Budd in 1859 that typhoid fever, an important
waterborne disease throughout human history, was spread by infective material
in feces, and that the disease could be prevented by avoiding fecal
contamination of water supplies.
Later, the germ theory of disease and the development of microbiological pure
culture methods set the stage for the isolation of Salmonella typhi and its
identification as the causative agent of typhoid fever (1880, Karl Eberth). In
1885, Theodor Escherichia isolated Bacterium coli (later, Escherichia coli) from
feces and noted it to be a natural inhabitant of the human intestine.
The nearly ubiquitous existence of E. coli in human feces was soon recognized,
and it was not long before the idea was proposed that E. coli could be used to
indicate that a water supply was contaminated with feces (1892, Franz
Schardinger).
Methods for identification of E. coli were not as easy in the late 1800s as
they are today. Other organisms that often existed in association with E.
coli were like it in many respects but could be distinguished by certain
physiological traits. Because of them
similarity, E. coli and these close relatives were termed “coliforms.” Testing for
the coliform group was simple, compared with E. coli. Microbiologists began to
regard coliforms as a testing alternative for E. coli and therefore, as indicators
, of fecal pollution. In 1914, the U.S. Public Health Service (PHS) adopted
coliform testing as a means of ensuring the sanitary nature of drinking water
supplies.
At that time, nearly a quarter of all food- and waterborne illness outbreaks were
caused by milk. The Pasteurized Milk Ordinance was developed by the PHS in
1924 as a measure to prevent milkborne disease. In addition to pasteurization
standards and recommendations for sanitary production, the Ordinance
included coliform testing of the pasteurized milk. Also in that year, a multistate
outbreak of typhoid was traced to consumption of oysters harvested from
sewage-polluted waters. The National Shellfish Sanitation Program swiftly
followed in 1925, and among the recommendations to enhance consumer safety
was coliform testing of shellfish growing areas and harvested products.
Criteria for an Ideal Indicator Organism:
∙ The organism should be useful for all types of water.
∙ The organism should be present whenever enteric pathogens are present.
∙ The organism should have a reasonably longer survival time than the
hardiest enteric pathogen.
∙ The organism should not grow in water.
∙ The testing method should be easy to perform.
∙ The density of the indicator organism should have some direct
relationship to the degree of fecal pollution.
∙ The organism should be a member of the intestinal microflora of
warm-blooded animals.
Commonly Used Indicator Organisms:
Many different types of indicators have been advocated for use in
particular applications; however, this minireview is limited to the most
common indicators used for foods and drinking water, i.e., the aerobic
plate count; coliforms; E. coli; Enterobacteriaceae; Listeria spp.; and the
yeasts and molds. Microbial groups which may have use as indicators in
certain applications, e.g., enterococci, Staphylococcus, endospore-formers,
lactic acid bacteria, and others, have not been included in this discussion,
nor have cellular components, products or nonorganismal agents, e.g.,
ATP, phosphatase, endotoxin, coliphages.
