Serial dilution technique-

Listar and his coworkers employed this technique to separate a single species from a mixture in which it was a predominating type. A small amount of the material, which contains mixture of bacteria is added to a test tube containing sterile medium of known volume. A stage will be reached when higher dilutions will contain no organisms and will show no growth upon incubation. Some of the tubes of higher dilution showing will be found to contain only one colony of a species, which can be ascertained by microscopic examination.





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Streak plate technique-

The inoculum is streaked or spread over the surface of a solid medium. The streaking process accomplishes a thinking out of the population. There is no uniform distribution of the organism. Where they are thickly populated, they will grow in mass, but where only few are present, they develop distinct colonies. These isoalated colonies are the progenies of single cells and whether they are so may be verified from microscopic examination. Pure culture may be recurred by the transfer of a part of such colonies to a container with suitable culture medium.

Single-cell isolation technique-

The best way to secure a pure culture from a mixed one would like to pick out a single cell of the desired type. This can be done by the use of micromanipulator in contamination with a microscope. Micromanipulator has a micropipette with a very fine capillary point. The micropipette can be moved as desire. A single cell can be picked using micropipette and transferred to a suitable nutrient medium.

Disadvantages-
This technique requires a skilled operator, is cumbersome to operate and involves greater chances of contamination during operation.

Direct transfer technique-

Sometimes beacteria, yeasts and moulda may be found in pure culture under conditions. Such cultures can be directly transferred to a suitable medium. Several molds produce aerial conidia which are comparatively free from comtaminations.
A pure culture can be obtained by transfer of infected blood with proper precautions to avoid contamination.

Numerical taxonomy-

Isolation of pure culture-
Growth of microbes in or on a laboratory medium is known as “Culture”. A growth of this type on a solid medium, which has originated from a single cell or spore is termed “colony”. A culrure, which contains only one species of microbe is termed a “ pure culture” and one which consists of several species is called a “mixed culture”.
Microbes are ubiquitous. It is very difficuly to obtain pure cultures of bacteria in nature.they usually exist as mixed cultures in their natural habitats, but it is essential to have pure culture of an organism before one can study its charasteristics. To obtain organisms in pure cultures various techniques have been employed.

Genetic or Molecular approach-

Phenotypic characteristics of any given organisms are the expression of a large number of genes that control the expression of genes is ultimately determined by DNA baksequence of bacteria.

Classical approach-

The classification is based on numerous properties: morphological, cultural, nutritive, biochemical, physiological, serologic, bacteriophage succeptibility pathogenic and genetic properties of organism.
Adansonian approach-
It resembles the classical approach in that a large number of charecteristics are determined for each organism of a group, but each phenotypic characteristics is given equal merit rather than placing more weight on some characteristics than on others.

Main approches to microbial classification-

1) Classical approach
2) Adansonian approach
3) Genetic or Molecular
4) Numerical taxonomy

Fundamental principles of Microbiology

Microbiology is a branch of biological science and includes the study of microscopic living beings both plant and animal such as bacteria. Bacteria belongs to a group of living organisms known as microbes without distinction regarding whether they are plants or animal. They are so called because of their small size. The study of micro organisms is a basic prerequisite because bacteria resume as living models.
The very best human eyes, unaided, failed to see objects less than about 100mm. So there was a need to make use of magnifying lens and see the microscopic objects. Robert Hooks made and used a compound microscope and observed moulds.

Transmission-

Human beings themselves are the main reserviour of most diseases that affect them. Transmission of the excreata-related diseases from one host to another follows one of the routes.
Control-
If transmission of diseases blocked at one or more points, excreate-related diseases can be controlled or possibly eradicated. Good sanitation practice can help towards the goal. eg. Water-seal slabs in latrine reduce the breeding sites for mosquotoes, vectors of filariasis. Treatement of excerata prior to its disposal can kill the eggs and cysts of many human parasites like Ascasis, Entamoeba, Schistosoma spp thus preventing contamination of both ground and water. Instead of treating human excreata as a social problem, if ways are devised where it could be used as a natural resources to be conserved and reused under careful control, then many of the associated problems could be corrected. There are three basic methods of using this sources.

Solid waste disposal and control-

The inadequate and insanitary disposal of infected human faeces leads to the contamination of the ground and of sources of water. It provides the sites and the opportunity for certain species of files and mosquitoes to lay their eggs, to breed, or to feed on the exposed material and to carry infection. It also attracts domestic animals, rodents which apread the faeces and also the potential for the diseases. In addition, it intolerable nuisance of odour and sight. There are number of communibale and noncommunibale diseases related to excreta and waste water. Major communicable diseases are intenstinal infections and helminth infestations, cholera, typhoid, paratyphoid, dysentery and diarrhea, hookworm, schistosomiasis and filariasis. Some of pathogenic organisms found in faeces, urine etc.

Prevention-

Many of the sources of noise can be controlled by public. Blowing of automobile horns, rattling trucks, noisy breaks, loud speaker, loud radios are some such examples. Prevention of noise will require
1) Education of the public
2) Co-operation of the industrial entrepreneurs, transport authorities and
3) Enforcement of adequate legislative measures.
The community may have demarcation of silent zones in different areas of a city, prohibition of blowing of horns near hospitals, schools and public offices, use of horns that are free from shrill etc. Use of loud speakers and loud radios can be restricted.

Noise-

A sound becomes noise when it causes disturbance to the hearer. Noise is measured in units of decibel. Loud noise may be cause direct injury to the auditory organs resulting in deafness. Permanent deafiness may be caused by exposure to sudden noise of an explosive nature. Temporary deafiness may occure after exposure to a light intense sound from jet engine. It has been observed that normal development of infants is interfered with by constant loud noise. Noise interfered with restful sleep. Onset of cardiovascular and cerebrovascular syndromes has been associated with disturnbance by noise.

Air borne harmful agents-

These agents are dust, industrial waste and industrial pollutants. Cities with heavy industries and vehicular transport can lead to pneumoconiosis, silicosis, lead poisoning etc.
Light-
Natural or artificial light is available at all places. Natural sunlight should be used wherever possible both for economy and for its beneficial effect on health. It is obtained by providing windows which should have an area of at least 1/10th of floor space. The rays of sun include visible rays, heat rays and invisible ultraviolet rays.in industries, inadequate lighting is uneconomical as the output leads to fall and the accident rate might increase. No worker should be permitted to gage directly at a bright light and every effort should be made to ensure that glazing light does not enter the eye obliquely.

Bacteria

Pathogenic microbes are present only in the vicinity of patients with related diseases.
Ventilation considers maintaining atmospheric conditions which are comfortable for the human body. The amount of air required for sufficient ventilation depends on factors like size of the room, number of persons on factors like size of room, no of persons occupying the room & impurities present in the room. In order to limit the concentration of carbon dioxide to less than 0.02%, each individual is advised to have at least 3000 c.ft.air per hour. In case of sick persons it is advised to be increased to 3750 c. ft. If the space available per head is a fraction of the required minimum then the air will have to be changed frequently e.g.300 c.ft.requires air to be changed at the rate of 10 times per hour. It is observed that warm air, after rising to the height of 12 feet, gets cooled & falls down again. Thus for a floor height of about 12 feet, the floor space should be 1/12 th of the total cubic space.

Dust

The inorganic particles in atmosphere are composed of silica, aluminium silicate, carbonate and phosphate of calcium, magnesium etc. Particles in the air of houses contain debris arising from wear and tear of articles like soot, ashes, scales of fibres of cotton, particles of hair, spores, pollen grains etc.

Respiration of air-

The major impurities in the expired air are carbon di-oxide, water vapours and organic matter . when the amount of air of a particular room rises to above person, the air becomes stuffy, however stagnation of air and reduced oxygen are the contributory factors to cause symtoms like drowsiness, headache, nausea etc. in over-crowded rooms. In case of persons suffering from pneumonia, diphtheria, tuberculosis etc. microbes in large numbers may come out during coughing, sneezing loud-speaking.

Health and air, noise, light-

Air-
The two mportant functions of air are-1) interchange of gases in the process of respiration 2) regulation of body temperature.
pure air has following composition-
1) Oxygen 20.95%
2) Carbon dioxide 0.03 to 0.4%
3) Nitrogen 79%
4) Water vapour variable
5) Ammonia,Ozone, Argon, Mineral Salt: traces
In open air the composition is fairly constant because of air currents, activities of plants etc. water content in the air are variable. During rainfall or in the vicinityu of the sea, huminity is higher. About 65% to 75% of humidity is considered conducive for health. The wind, the rain, oxygen and photosynthetic activities because of green content in the leaves are the important factors on which purification of air depends.

ACCIDENTS-

It must be appreciated that accidents can’t just happen, and can be prevented if due care and precautions are taken. Many of the accidents are the result of careless, thoughtlessness and neglect on part of human being.The senseless, thoughtless and careless acts and uncontrollable emotions are the basic reasons behind the happening of accidents. Although accidents can happen anywhere; it is easy to identify the place where most probly the accidents occur. In general accidents occur at the place where either human or any other form of power is in action. The accident places may be grouped into theree groups viz.
1) Indoor accident
2) Outdoor accident
3) Special category of accidents
1) Indoor places of accident
a) Kitchen, where gas, stove, electrically operated kitchenwares cookers and like appliances are used. b) Bathrooms where electric gaysers are used, and the acid bottles for cleaning are stored. c) Sitting rooms, and dining rooms
2) Outdoor places of accidents-
a) Roads b) Work places, where machinbes are used. c) Sports grounds.
3) Special category of accidents-
a) Poisoning, either accidental, such as food poisoning or intentional to commit suicide.
b) Bites and stings, such as dog bite, snake bite etc.
PREVENTION OF ACCIDENTS-
Accident prevention always better than copying with its effects.. As already pointed out accidents occure due to senseless acts and emotional outbursts, hence accidents may be prevented by being sensible and controlling emotions while acting. Get rid from some of the factors such as tiredless, streress, worry, anger that are responsible for faulty acts. Take due precautions while handling electric appliances, follow the rules to prevent fire.; take care of your habits and obey the rules while handling machinery. These are few of the hints if carefully observed would help to prevent accidents.

DETERMINANTS OF HEALTH:-

A) INDIVIDUAL:-

1) GENETIC:- Herediatory factor is one of the causes of certain disease. The genetic characters inhereted from parents are responsible for giving rise to some kind of illhealth. eg. there are greater chances that the children of diabetic parents may suffer from diabetes. The state of health therefore depends partly on the genetic constitution of individual.

2) LIFE STYLE:- The way of style attitude towards life and awareness regarding healthy living all affects the health of individual. The life style affects health in both the ways ie. it may maintain health or it may adversly affect the health.

B) ENVIRONMENTAL:-

1) SOCIOECONOMIC DEVELOPMENT :- The way of life of human beings is governed by the set of rules and regulations framed and accepted byt the society in which they live. Many customs and traditions of a particular human society may affect healty of individual. Development of society plays important role in getting rid from health hazardous customs and traditions.Socioeconomic development and growth of society is multifactorial in nature. Integrated effords of different sectors result in the development of society. Thus inprovement in economic, educational, cultural sectors can collectively cause development of society. It is essential to realize that we are very much of the health is "not merely" an issue in isolation, but very much a part of the development process.

2) POLITICAL WILL:- If we look at the causes of illhealth then we can see that thepoverty is the root cause. The poor people living in slums, lacking good hygeinic conditions are the targets of disease agents. People in rural areas who do not have access to health seevices, and who can't afford to pay for medical treatment are too the victims of ill health. How far the policy makers are aware of the health problems of this group of people is issue primarily of political nature.The policies framed and implemented with the object of maintaining and promoting health of these people can certainly affect status of these communities.

Industrial pollution-

Water pollution occure due to the presence of dissolved inorganic materials, organic materials like proteins ,fats , carbohydrates and physical factors like turbidity, colour, temperature of effluent, radioactivity etc.
Organic pollution due to presence of higher molecular weight compounds like sugars, oils, fats and proteins are obtained from distillery, canning like sugar and other food-processing industries. Some wastes from pharmaceutical and petroleum industries contain phenols which are toxic to fishes.
Turbidity of waste water is caused by the presence of colloidal matter which does not sel=ttle readily. This consist of fine clay particles, milk wastes, seage. Synthetic detergents, effluents from industries like paper-pulp, dye-stuff, tanning and textile industries add colour to the effluent.

Purification of water-
Impure water may be purified by one of the following method-
A) Natural 1) Pounding or storage
2) Oxidation and settlement.
B) Artificial 1) Physical
a) Distillation
b) Boiling
2) chemical
a) Precipitation
b) Disinfection
3) Filteration
a) slow and filteration
b) Rapid mechanical filteration
c) domestic filteration

Natural method of storing water helps in settling down of suspended particles. Use of a co-agulant like Aluminium sulphate in the contration of 13-50mg/lit. is suggested. Most of the settles down in the process. Oxidation with potassium Permaganate at a concentration of 5 parts per million are advisable.
Artificial method of distillation is used in chemical laboratories. Boiling removes solid material like chalk, obnoxious gases, organic matter and microbes. It is adapted as a precautionary measure in the presence of an epidemic of water-borne diseases. Use of filteration removes suspendes matter, the ova, cysts spores and bacteria. Slow sand filters use layer of bricks, broken stones, pebbles coarse and fine sand. The process of filtetarion is slow. It may take about 3 days for new bed of filters to be active. Rapid mechanical filters may be of pressure or gravity type. They are quick and filter about 450-600lit/24

Water Pollution-

The introduction of modern water carriage system transferred the sewage disposal from the strrets and the surrounding of townships to neighbouring streams and rivers. This initiated the problem of water pollution. With rapid urbanization and industrialization the problem of the pollution of natural waters is reaching alarming proportion.
The problem is more complicated where distribution of water is more uneven and fluctuating. Under such conditions, polluted waters are not sufficiently diluted. As a result the river waters do not get natuarally purified.
With expanding industries, the waste waters are discharged in neighbouring streams and they become progressively unsuitable as sources of potable water. Fish life may be ruined. The problems are becoming increasingly serious with higher degree of industrialization and higher standards of living.
All liquids wastes find there way to inland or coastal waters; hence pollution may be diminished be treatement of sewage and industrial wastes. It is depends on following factors.
a) Characteristics of sewage and waste water and their effects on probable use of the receiving streams.
b) The quantity of waste water.
c) Proximity of downstream municipalties, village communities and industries.
d) Possible harmful effects of waste water on the structure of sewage system.

Benefits of control-
The benefits which result from prevention of water pollution include a general improvement in the standard of health of population, the possibility of restoring stream waters to original beneficial state and rendering them fit as source of water supply and maintainance of clean and healthy surroundings.

ENVIRONMENT AND HEALTH-

The main sources of water supply are-
1) Rain water or snow water and artificial lakes.
2) Surface water eg. Canals, rivers, tanks and ponds
3) Upland surface water eg. Lakes
4) Ground water eg. Wells and springs
5) Sea water
1) Rain water is pure initially; however it receives impurities from the atmosphere such as dust, soot, suspended matter, microbes, gases etc. Normally it is not pathogenic. Rain water if properly collected and stored is a safe water. It is soft as it contains no minarl salts in it. It is suitable for cooking, washing and bathing. It is soft and liable to corrode lead pipes and thereby cause lead poisoning.
2) Rain water on reaching the ground , or the melted snow from hills begins to flow as a river, canal, stream, lake or a pond and is called surface water. Since it may travel a long distance, it contains suspended materials. The water from these sources is collected in large reservoirs or settling tanks. Subsequently water is filtered and sterilized further by chlorination or other methods to make it suitable for drinking.
3) Upland surface water runs on the side on hills, slopes and valleys and is taken off as water supply before it forms big streams and rivers. An upland water is safe because it is pure rain water which has travelled a short distane. It needs purification by running through a bed of fine sand before final storage.
4) Wells and springs are important sources of ground water. An ideal well should be tapped in a good soil and should be at least 200ft. away from possible contamination source. No washing of clothes, utensils and bathing of persons be allowed near a well. Well-water may be treated with solution of 1 part of freshly prepared lime to 4 parts of water or bleaching powder, or potassium permagnate solution.
5) Distilled sea water is used for drinking purposes. For aeration of the distilled water it may be passed through a long column of wood charcoal; subsequently it is tasty and can be used for drinking purpose.

Neck and Spine Fracture-

The spinal cord is a link of nervous tissue between the brain and the rest of body. It passes down through the vertebral column. Injury to the nect and spine may causes sever pain in neck and back regions and paralysis of body part below the injured spot.
Treatement-
1) Do not move the victim until absolutely necessary
2) If he is to be moved; use firm support for moving
3) Do not permit the victim to rotate his head; while moving take the help of another person to hold victim’s head on line with the spine.
4) Arrange for moving the victim ho hospital.
Chest Fracture-
Thoracic cage protects heart and lungs. If a broken rib should pierce a lung; bright red, frothing blood may be cpughed out. A penetrating wound could also produce bleeding from mouth.
Treatement-
1) If broken rib is suspended gently support the arm on the injured side in sling.
2) If there is open wound sucking the air, cover it immediately to keep the air out.
3) Lay the victim down and incline towards the injured side.
4) Arrange for quick transfer to hospital.
Burns and Scalds-
These are the injured caused due to contact with or too close heat and strong chemicals. Burns are injuries caused by open fire, chemicals, electricity etc. while scalds are injuries caused by moist heat (steam). Both burns and scalds cause similar damage to body tissue and hence the first aid treatement is similar. The severity of burns may vary from minor reddining of affected part (first degree) through blister (second degree). The most serious consequence in burning is the occurrence of shock. Infection due to contamination of burnt area is another serious condition that may follow the burns.

DISEASES

1) Blindness:- If the person’s cannot count fingers at a distance of 1 & half meters than he/she is considered blind.
2) Cancer:- * Cancer is mostly seen after age 50 years. *Smoking is strongly associated with lung cancer.*Early marriage & low level of genital hygiene are linked to cancer of cervix.* tobacco chewing is associated with oral cancer.*Drugs like butazolidine, urethane and estrogens are associated with cancer.
3) Diabetes:- To prevent diabetes avoid marriages among persons with known familial traits.*Prevention of obesity keeping Weight about 10% less than optimum.
For diet control daily exercise, use antidiabetic drugs & mainly they win by losing weight.