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Comparative Study Of Antibacterial Activity Of Two Selected Medicated Soap And One Local Black Soap On Staphylococcus Aureus From Wound Infection
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Several
specials of micro-organisms produce molecules and may render a product
dangerous if they grow in it under conditions supporting toxin
production. Endotoxins, produced by Gram-negative bacteria such as
Escherichia coli, are intimately bound to the cell, lipopolysaccharide
in nature and are not necessarily inactivated by sterilization as they
are heat stable. Toxins of this type are poorly absorbed by the oral
route but are very important in connection with injectable products,
particularly perfusion fluids. Exototins are much more highly lethal and
are bound less rigidly to the cell so that they are readily liberated
into the growth medium. The outstanding example, of course, is that
produced by Clostridium botulinumwhich is lethal to mice in doses of the
order of 0.1ng. Fortunately, conditions for growth and toxin production
are quite strict; anaerobiosis, the presence of suitable pH and
nutrients and of few competing bacteria is required. Such conditions are
not often attained in pharmaceuticals and cosmetics and we know of no
case of botulism arising from their use. Certain strains of
staphylococeusaureus produce a toxin, characterized as a specific
polysaccharide, but the organism must grow to a density of several
million cells per gram before its toxin becomes a problem. The evidence
in connection with other bacterial, e.gClostridium perfringens, Bacillus
cereus, streptococeusfaecalis, proteus and pseudomonas species is less
clear, but poisonous metabolites are certainly produced by a variety of
fungi. Over the last decade there has been much interest shown in the
afflatoxins produced by Aspergillusflavus(Barnes, J. M. (1970). These
heat-stable compounds exhibit potent toxic and carcinogenic properties
in animals. A. flavuscommonly infects peanuts, cotton seed and grain
which are all components of animal foods. Under poor storage conditions
mould growth occurs and toxic doses of aflatoxin accumulate in the food
stuff. While it is difficult to visualize this occurring with cosmetics
or pharmaceuticals, it is wise to ensure that ingredients such as talc,
kaolin or starch are not stored for long periods under conditions
supporting mould growth.
Metabolic Products:
In addition to
microbial toxins, which are complex molecules and may be looked upon as
biosynthetic products, simpler catabolic products such as organic acids
and amines, which can be toxic to man, may be produced. Indeed, many
microbial metabolites exhibit pharmacological activity (Perlman,D. and
Peruzzotti, G. P.(1970). As these compounds are considerably less toxic
than are the classic bacterial toxins, relatively high concentrations
have to be attained before a spoiled product causes illness and the
sense often detect that something is wrong before food spoiled to this
extent is swallowed. This may not apply to medicines, as they are
expected to be unpleasant and, indeed, frequently contain a flavouring
agent in order to mask an unpleasant taste. However, well-documented
examples incriminating specific metabolic products in pharmaceuticals
are not easy to find.
Irritancy:
Incidents of irritation following
the application of cosmetics occasionally occur, and the offending
preparation may subsequently be shown to contain a high level of
microbial contamination. Direct evidence that irritation is caused by
the presence of the micro-organisms is lacking but it is reasonable to
suppose that, on some occasions, the contaminants provide a source of
foreign protein evoking an allergic contact dermatitis reaction or that
high levels of a microbial metabolite will cause a primary irritant
reaction. The eye, of course, is particularly susceptible to infection
from contaminated cosmetics and it is also at risk from the direct
effect of irritant metabolites left in a product even after the
organisms producing them have been eradicated.
Change of activity:
An
interesting aspect, but perhaps not one of great significance, is the
inactivation of biologically active molecules by organisms contaminating
a formulation. Several examples have now been demonstrated in the
laboratory and in some cases have been observed to occur in practice. A
classic example is the destruction of penicillins by penicillinases,
enzymes produced by a broad range of micro-organisms. Microbial enzymes
which inactive chloramphenicol are also known (Smith, G. N. and
Worrel,(1949) and the destruction of preservatives and disinfectants is
established (Hugo, W. B.(1965). Pharmacologically active substances can
also be degraded. For instance Kedzia, Lewon and Wisniewski (Kedzia,
W.,et.al(1961) found that a loss of atropine of up to 20% in eye drop
could be caused by Corynebacterium and Pseudomonas spp. isolated from
the eye drops and atropine itself. Recently, Grante, de Szors and Wilson
(Grant, D. J et.al.(1970) have shown that in the laboratory, a strain
of AcinetobacterIwoffi, obtained from distilled water, utilized aspirin
as a sole carbon source in a mineral salt solution. The same organism
metabolized other active esters; for instance it could degrade heroin to
morphine. Another organism, Corynebacteriumhoffnaii, which was isolated
from laboratory dust, metabolized and analgesics, aspirin, phenacetin
and paracetamol.Loss of useful activity is not restricted to
pharmaceutical products. For instance emphasis on the need for
detergents which are biodegradable has had some repercussion and
shampoos have been known to lose their surface-active properties due to
degradation of the surfactants by contaminating bacterial.
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ABSRACT - [ Total Page(s): 1 ]Cosmetic(creams) need not be sterile,however they must not be unduly contaminated with micro-organism and should remain in a stable state throughout the shelf life of the product (or when be used by the consumer).the aim of this project was to determine the microbial load in selected creams and to identify the specific contaminants.For the determination of the number of contaminants, 1 mL of each cream was diluted to a factor of 104,1mL of this dilution was mixed with cool nutrient agar and macC ... Continue reading---
