eChapters

1. Introduction
All glassware used for bacteriological work must be meticulously cleaned and sterilized. Used and soiled glassware should be thoroughly washed to remove dirt and solid residues before drying and undergoing sterilization.
2. Cleaning of New Glassware
Borosilicate glass (e.g., Pyrex) and factory-washed soda glass require only standard washing before use. However, new, unwashed soda glass needs additional treatment to neutralize alkali content.
• Place the items (e.g., test tubes, Petri dishes, and flasks) in a suitable container, cover with a 1% tri-sodium phosphate solution, and bring to a boil.
• Remove the items, rinse with tap water, and immerse them in a 1% hydrochloric acid solution to neutralize alkalinity.
• Rinse thoroughly with tap water, followed by distilled water. Allow the glassware to dry before sterilization.
3. Cleaning of Used Glassware and Other Apparatus
• Autoclave all glassware contaminated by microorganisms (121°C for 15–20 minutes). This liquefies solid media, facilitating removal.
• Rinse the empty glassware with tap water, then warm water (50–55°C).
• Soak in a detergent solution (e.g., 1% washing soda or tri-sodium phosphate solution) and scrub with a brush.
• Rinse thoroughly with tap water to remove detergent traces, followed by distilled water.

Introduction

A variety of glassware, plasticware, and other apparatus are used for experimental purposes in a laboratory. They need to be washed, cleaned, dried, and sometimes sterilized before they can be used in the next set of experiments. Glassware needs special care of handling during washing, drying, sterilization, etc. because even a minor mistake in handling of glassware may result in its cracking/breakage and it may become unserviceable. All of these may result in a delay in experimentation if spare piece of the glassware is not available or it may affect serviceability of the associated apparatus.

A large number of glassware such as beaker, flask, measuring cylinder, burette, test tube, etc. are regularly used in a laboratory, which requires careful handling during the different stages of experiment as well as after completion of the experiment while preparing them for another set of experimentation.

Glass being a complex silicate, its properties depends on the type of silicate anions in the structure and the cations formed. Thermal properties of glass changes by the addition of boron oxide (B2 O3 ); hence, borosilicate glass is extensively used in the laboratories. With this brief background information, let us discuss about the necessity, procedures, and precautions during washing, cleaning, drying and sterilization of laboratory-wares. Figure 3.1 shows various advantages of using borosilicate glass in a laboratory.

Good laboratory practices require clean glassware, because an experiment may give erroneous result if dirty glassware is used at any step of the experiment. Hence, the glassware must be physically and chemically clean; and in many cases, it must be microbiologically clean or sterile. The commonly used glassware in a laboratory include test tube, measuring cylinder, pipettes, beakers, flasks, microscopic slides, etc.

Water, of its very nature, as it occurs automatically in the process of cosmic evolution, is fit, with a fitness no less marvelous and varied than that fitness of the organism which has been won by the process of adaptation in the course of organic evolution.

WATER IS ABSOLUTELY ESSENTIAL FOR ALL LIVING ORGANISMS

The evidence:

Most organisms are comprised of at least 70% or more water. Some plants, like a head of lettuce, are made up of nearly 95% water;

When organisms go dormant, they loose most of their water. For example, seeds and buds are typically less than 10% water, as are desiccated rotifers, nematodes and yeast cells;

Earth is the water planet (that’s why astronomers get so excited about finding water in space).

Water is the limiting resource for crop productivity in most agricultural systems.

WATER IS VERY SPECIAL IN BIOLOGY

Most abundant chemical of life

Special properties:

Introduction

In a research laboratory, we frequently need weigh chemicals and prepare different solutions of varying strength, as per the requirements. Accuracy in weighing and preparation of solution, with respect to weight/volume and strength, determines the success of experiment. In turn, the accuracy depends on weighing of solid chemical and/or measuring the volume of liquid chemical/making up the volume. In this Chapter, weighing of chemicals using appropriate weighing balance, preparation of solutions of different strength, their dilution, and precautions while preparing will be discuss in brief.

Weighing of Chemical

The primary method to determine the amount of chemicals to be used is weighing the chemical by using a balance.

In general, there are two types of balances to weigh chemicals in a laboratory:

1. Standard laboratory balance

2. Analytical balance

Standard Laboratory Balance

Generally, a standard laboratory balance is used for weighing a chemical when an error of ±0.02 g is acceptable. It is also used for pre-weighing, where approximate mass needs to be determined. Precise mass of the chemical is then determined using an analytical balance. Following are the steps in using a weighing balance in a laboratory.

When certain disease-causing bacteria or pathogens contaminate food, they can cause foodborne illness, often called “food poisoning”. Foods that are contaminated may not look, taste or smell any different from foods that are safe to eat. Salmonella, Campylobacter, Listeria and Escherichia coli are common bacteria causing foodborne illness. Some foodborne illnesses are mild where most people get better within a few days, but illness can sometimes be more severe and fatal. Bacillus cereus can form heat resistant spores. On cooking the food with these spores the heat resistant toxin is left at room temperature. Reheating or lightly cooking the food does not destroy these toxins. Most types of foodborne illnesses cause symptoms like nausea, vomiting, watery diarrhea, abdominal pain and cramps. Fever and/or the presence of blood or mucus in the stool are signs of bacterial infection that may require a medical consultation. Proper food handling is vital to prevent most foodborne illnesses and diseases. WHO has given keys towards safer food which should be followed. Unsafe food containing harmful bacteria, viruses, parasites or chemical substances, causes more than 200 diseases which range from diarrhoea to cancers. Foodborne and waterborne diarrhoeal diseases kill around 2 million people worldwide annually, including many children. A single foodborne bacterium can grow into more than two million bacteria in just seven hours under the right conditions. Foodborne pathogen called Listeria sp. can survive and sometimes grow on foods being stored in the refrigerator. Hepatitis A virus can cause long-lasting liver disease and spreads typically through raw or undercooked seafood or contaminated raw produce. It is estimated that more than 250 million people worldwide suffer food allergies. The boiling temperature (smoke point) of cooking oil is above 200 °C. The boiling point of water is 100 °C.

According to the World Health Day (WHO,2015) food contamination happens when food are corrupted with another substance. It can happen during the process of production, transportation, packaging, storage, sales and cooking process. The contamination can be physical, chemical and biological. Faulde et al., (2013) studied the infection caused to patients by mothfly

It is a discipline of science that describes handling, preparation and storage of food that can prevent food-borne diseases. When there are two or more cases of a similar illness from the ingestion of the same common food it is known as a food-borne disease outbreak (FSN, 2018). In order to avoid potential health hazards, food safety is very important. This needs safety between industry, market and the consumer. For food safety the labelling on food material is vital. This includes the origin of food, steps taken for food hygiene, food additives, pesticide residues, policies on biotechnology, food guidelines for the management of governmental import, export inspection and certification systems for foods. The food should be safe in the market with safe preparation and delivery of the food for the consumer. Foegeding et al., (1996) have done an assessment of risk factors with food borne pathogens.Warnock et al., (2007) have reported intervention to food safety.

When pathogens are in the food they may be transmitted to the consumer. It may result in an illness or death of the person or other animals. The pathogens include bacteria, viruses, molds and fungus. These multiply in the food medium. Joon et al., (2012) have found pathogenic bacteria in meat products of Korea. The developed countries have high intricate standards for the preparation of food; however, in the developing countries there are less standards and enforcement of the standards which are followed. Apart from food another major source of infection is water, which is very critical in spreading many diseases. It is possible to prevent food poisoning if good water is used for all purposes. However, it becomes difficult as in the food supply chain a large number of persons are involved apart from the fact that pathogens can be introduced into foods no matter how much precautions are taken. Cowden (2000) has studied the notification on food poisoning to improve health. Frenkel et al., (2015) studied the amount of wastes from food processing industries.

A process control system that identifies the hazardous points in the food production process is known as HACCP (Hazard Analysis Critical Control Point). It puts into place many stringent actions to prevent any hazards from occurring. In any food process if there is strict monitoring and controlling steps, the chances for hazards are minimum. Today, HACCP is an integral part of modern food industry that identifies and controls the major food risks. These are like microbiological, chemical and physical contaminants. These can also be practiced at home scale by checking proper storage, handling, cooking and cleaning procedures. These steps have resulted in industries taking greater responsibility for and controlling the food safety risk factors. This helps in better consumer protection, agriculture, the food processing industries and promotes domestic and international food trade.

The temperature of food storage is important. Below 4⁰C the food pathogens do not grow. Above 60⁰C some colonies begin to die. However, almost all die at 71⁰C. How hot is the food served is important for food safety. The size of the piece is important to how quickly it will cook all the way through. The smaller the piece the faster it will cook. Large or thicker pieces take a longer time to be cooked. Otherwise cooking for a longer time is better so that pathogenic microorganisms do not grow. In case of a thicker piece the color must be checked inside to outside after cooking which should be consistent. If the meat has the bone, check the color/temperature closest to the bone in the thickest part. In case of meat the contamination usually gets introduced while butchering and the practices used. The street food on a cart is perhaps the most contaminated as it has some level of bacteria in it. The meat in the decorated malls also has pathogenic bacteria. The environment plays a very pivotal role which can recontaminate the food even after proper cooking. The amount of harmful pathogens keeps growing in number with the passage of time. Fresh from the grill is the best, an hour or two is not ideal, half a day or overnight could make a person sick. Due to the reason that consumers do not know the time and temperature of cooking it is important to eat food which is freshly prepared.

If you are inclined to make research as a career, the first question is why are you interested in research or making it as a career in your life -whether for money or to pass a cozy life in a government institute or to get fame or to solve some scientific problems - related to cosmos, Agriculture, animals, human health, search some medicinal plants or you have great passion for science and impressed with its power to find solutions for many universal problems ? Or it is un-employment, now rampant in every field, which is deriving you to join higher degrees and research. Many times, this unemployment or no vacancies in due time leads the young persons to continue their post graduation or joining doctorate program with the hope that some vacancy will arise in the ensuing period or a suitable job may fall after or prior getting a Ph.D. degree.

What so ever you are doing as a researcher, one important task is to publish the same for scientific fraternity for establishing your view points else no body will recognize you and your competence. Your credentials are judged by the research papers published by you and its impact on scientific community. Therefore, it is must to publish what so ever you are doing to establish yourself in the scientific community and also to advance science. This implies to select a national or international journal for your research publication which has wide scientific circulation so that peers of scientific world may observe your publication. Adversely, the publication may bring you criticism if it does not stand on scientific parameters and you may lose your reputation in your profession.

Yersinia species are non-lactose fermenters and, with the exception of Y. pestis are motile. Although there are more than 10 Yersinia species, only Y. pestis, Y. enterocolitica and Y. pseudotuberculosis are pathogenic for animals and man. Yersinia ruckeri causes perioral haemorrhagic inflammation in some species of fish. Growth of yersiniae tends to be less rapid than other members of the
Enferobacteriaceae. They characteristically demonstrate bipolar staining in Giemsa-stained smears from animal tissues
Natural Habitat
Y. pestis, the cause of bubonic plague in man and a sylvatic cycle in animals, is transmitted mainly by fleas from tolerant rodents. Human infections through cuts, bites, scratches and aerosols can also occur. Cats are susceptible to Y.pestis and naturally infected cats can pose a health hazard for humans in endemic areas. Y. pseudotuberculosis persists in wild rodents and birds as well as in the environment. The intestinal tract of wild and domestic animals appears to be the reservoir for Y. enterocolitica. Pigs, particularly, are carriers of Y. enterocolitica strains pathogenic for humans.
Isolation
Yersinia species grow on nutrient, blood and MacConkey agars but the colonies, after 24 hours incubation, tend to be smaller than those of the other members of the Enterobacteriaceae. Y. pestis grows poorly on agars containing desoxycholate whereas Y. enterocolitica and Y. pseudotuberculosis grow well on these media. Yersinia selective medium (CIN agar) containing the antibiotic supplement cefsulodin (15mg/litre), irgasin (4 mg/litre) and novobiocin (2.5 mg/litre) is designed for the isolation of Y. enrerocolitica from faeces.