Bacteriological contamination

Risks to the consumer from seafood can come from either naturally occurring bacteriological contaminants or manmade environmental contamination. 

Table 3 Evaluation of water-table aquifer vulnerability by bacteriological contamination...

Period of vital functions of bacteria under slow contamination is taken 200 days, under mass infection (natural or man-caused disaster) or continuous contaminant spill conditions it is taken 400 days. Six categories of ground water vulnerability to bacteriological contamination have been distinguished (Table 3) ... 

Vulnerability assessment from bacteriological contamination is given in Table 5. The water-table aquifer is evaluated as slowly protected (TOT = 50-100 days) and protected (100-200 days). 

Table 5 Water-table aquifer natural vulnerabihty assessment from bacteriological contamination ...

Fires, explosions, burns, poisoning, electrical shock, bacteriological contamination, chemical burns, and broken glassware. Produced by Layton International. 

A less obvious advantage of a 70% AM ethoxysulphate is its much greater resistance to bacteriological contamination than a conventional 25-30% AM material. 

Morin, P., 2000. Identification of the bacteriological contamination of a water treatment line used for haemodialysis and its disinfection. Journal of Hospital Infections 45, 218-224. 

Baird, R. M., 1984. Bacteriological contamination of products used for skin care on babies. Int. J. Cosm. Sci, 6, 85-90... 

Bacteriological sampling is performed by manual techniques because of stringent sterilization requirements. Samples are taken in wide-mouthed, sterile, glass-stoppered bottles that are wrapped in paper prior to sterilization in an autoclave at 138 kPa (20 psi) or in an oven at 170°C. The botde is unwrapped and the lower portion is held in the hand. The sample is taken with the botde mouth in the direction of the flow. The stopper must be protected from contamination, the botde only partially filled, and the sample stored at 4°C after sampling. For bacteriological samples withdrawn from a tap, the water should mn for five minutes and then be shut off the tap should then be sterilized by flaming before a sample is taken. 

The goal of filtration in the modem municipal treatment plant is a maximum of 0.1 ntu (nephelometric turbidity unit), which ensures a sparkling, clear water (8). Freedom from disease organisms is associated with freedom from turbidity, and complete freedom from taste and odor requites no less than such clarity. The National Interim Primary Drinking Water Regulations (NIPDWR) requite that the maximum contaminant level for turbidity at the point of entry into the distribution system be 1.0 ntu unless it can be shown that levels up to 5 ntu do not interfere with disinfection, interfere with the maintenance of a chlorine residual in the distribution system, nor interfere with bacteriological analyses. 

Water quality must be studied as well as quantity. Chemical and bacteriological examination will indicate the extent of treatment required and will aid in the development of water cost estimates for comparison with other locations. The possible contamination of the water source by other industries in the area should be anticipated. Note that "contamination" may consist of raising the temperature of the water to a level that renders its use as a cooling medium impossible. 

Robinson, I. and Adams, R.P. (1978) Ultra-violet treatment of contaminated irrigation water and its effect on the bacteriological quality of celery at harvest . Journal of Applied Bacteriology, 45, 83-90. 

An adequate supply of clean, potable WATER is one of the primary requirements for good health. Traditionally, health hazards associated with water have been the classic waterborne diseases, namely, typhoid, cholera, and hepatitis. The advent, advancement, and practice of the science of bacteriology after the late 18th century led to the recognition of the causes and sources of these diseases, which resulted in the development of disinfection processes and in the recognition of the necessity to prevent public potable water sources from pollution from sewage and postdisinfection contamination. 

It is of the utmost importance to insure that aseptic technique is used throughout these procedures. The work place must be suitable for bacteriological work. It is very difficult to produce meaningful work where there are air currents and laboratory traffic. Normal air contains bacteria and mold spores which can easily contaminate samples and plates. 

Mycotoxins generally affect the liver (hepatotoxins) or the kidney (nephro-toxins). The problem of mycotoxins in poultry was highlighted in 1960 when more than 100,000 turkey poults in the UK died from what was called Turkey X disease (Blount, 1961). At post-mortem the turkeys were found to be suffering from enteritis with engorged kidneys and /or hepatitis. Bacteriological examinations were negative. The problem was eventually found to be due to aflatoxin contamination in groundnut meal imported from Brazil. 

Like Portier before him, Wallin (1927) argued that is was merely a convenient matter to explain his results away with the dogmatic cry of contamination . He had assured his readers that all instruments and vessels had been thoroughly sterilized. The fetus or newborn rabbit after decapitation was saturated with 95% alcohol. The instruments used in opening the abdomen and removing the liver were always sterilized in the flame immediately before use. The liver was quickly removed to a sterile petri dish, cut into pieces by inserting a sterile scalpel under the lid. Pieces of the liver tissue were then planted in the media by the usual bacteriological technique. 

Stagnation of water during low or zero production demand is avoided at all costs so as not to promote bacteriological or biological contamination of either circuit. Therefore plants are designed to recirculate water in the polishing loop at least three times the maximum take off rate (m h ) at velocities of 2-3 ms in delivery pipework free of dead legs . 

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