Lab 4 Report prepared by Teoh Leong Sin

Name : Teoh Leong Sin

Matric no. : 111433

Introduction

      Airborne microorganisms are usually carried on dust particles, although some may be carried directly by air currents (for example,fungal spores). It is important for microbiologists to be aware of the potential for contamination by airborne microorganisms. Carefully observation of simple precautions dramatically reduces the risk of contamination of the cultures.

      Every human is colonized by billions of microorganisms. These microorganisms, some of them are vital to our wellbeing, constitute our resident or normal microflora. Resident microorganisms are nourished by the chemicals and moisture excreted by the human body. In moist areas such as armpit, there may be one million bacteria per cm^3; on the drier skin of the forearm, there may be 10000 bacteria per cm^3.

      Resident microorganisms are either nonpathogenic or are prevented from infecting the body by an array of mechanical and chemical defences. Some resident microbes are, however, opportunistic pathogens which may cause infection if the body's defences are breached. For example, if the skin is  broken.

      Transient microorganisms are picked up from our environment. For example, from faecal contact or from soil and usually fail to become permanent skin residents. One of the most important reasons for failure to gain permanence is that the established residents are better able to compete for nutrients. Since transients generally originate in other environments, they are poorly adapted to conditions on the skin and usually disappear within 24 hours of arrival.

      Microorganisms in the upper respiratory tract are either normal residents or transients. As with the skin, the normal microflora are largely consists of nonpathogen or opportunistic pathogens.

      Large numbers of transients enter the upper respiratory tract as we breathe or eat. They may also come from our own hands or or from  improper sanitation during food preparation. Regardless of their origin, most transients are nonpathogenic and are quickly killed by various defences arrayed against them.

Objective

To determine the microorganisms in the air and from healthy humans.

Results

1) Colonies in air :

2) Colonies of hands :

 

3) Colonies of ear:

 4) Colonies of normal breathing :

5) Coloniesof violent coughing : 

Discussion

1) Atmosphere contains all major groups of microorganisms ranging from algae to viruses. Microorganisms are very diverse, they include bacteria, fungi, archaea and protists, microscopic plants (algae) and animals such as plankton and the planarian.

Type of microorganisms

1) Bacteria:

Bacteria are prokaryotes , prokaryotic cells are simpler structures than eukaryotic cells .Bacteria do not have a nucleus, other membrane bound organelles, mitochondria or chloroplast.They have 2 major compartments namely the cytoplasm and cell envelope and exterior appendages,such as flagella.Classification of bacteria depend on their shape.There are rod or bacillus, cocci or spherical, and spirilla or curved walls.Bacteria reproduce via binary fission.

2) Fungi:

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. Fungi which is separate from plants ,animals, and bacteria. Do not differentiate into roots, stems and leaves. The true fungi produce masses of filamentous hyphae which form the mycelium. Some are rough, dull, wrinkled. Usually filamentous in shape.

3) Virus:

A virus is a small infectious agent  that can replicate only inside the living cells of organisms.Extremely small parasites. Require living cells of plants, animals, or bacteria as hosts for growth. Mainly a packet of genetic material which must be reproduced by the host. Virus is extremely small and cannot be seen through naked eye.Enveloped in a protein coat usually referred to as a nucleocapsid

4) Algae:

Algea are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many distinct organs found in land plants. The largest and most complex marine forms are called seaweeds. The term algae is now restricted to eukaryotic organisms. All true algae therefore have a nucleus enclosed within a membrane and plastids bound in one or more membranes. Algea has several types based on morphology of growing state such as filamentous and parenchymatous.

5) Protozoa:

Protozoa are single-celled organisms such as the amoeba which can cause disease in humans and animals.They possess cell structure similar to higher and more complex organisms.Protozoa have no inner or outer skeleton.They stores food in vacuoles and reproduce via fission. They mostly is aerobic.

Sources of contamination

1) Air:

Air is not a medium in which mircroorgnism grow but is a carrier of particulate matter , dust particles and spores.Microorganisms present in air are vegetative cells and spores of bacteria, fungi and algae, viruses and protozoa.Since air is often exposed to sunlight, it has a higher temperature and less moisture. Hence, most of these microbial forms will die.

2) Hands:

The skin microbes found in the most superficial layers of the epidermis are Gram-positive cocci (Staphylococcus epidermidis and Micrococcus sp.) and corynebacteria such as Propionibacterium sp. These are generally nonpathogenic and considered to be commensal, although mutualistic and parasitic roles have been assigned to them. For example, staphylococci and propionibacteria produce fatty acids that inhibit the growth of fungi and yeast on the skin. But, if Propionibacterium acnes, a normal inhabitant of the skin, becomes trapped in hair follicle, it may grow rapidly and cause inflammation and acne..

3) Ear:

The outer ear contains bacteria, yeasts and molds. Bacteria cause most ear infection. Coagulase-negative staphylococci, dominated by Staphylococcus epidermidis, were the commonest microbe group found in outer ear. The only Gram-negative rod found was Hafnia alvei in 4% of individuals. No Vibrio spp. or anaerobic Gram-negative organisms were found.

4) Normal breathing:

A large number of bacterial species colonize the upper respiratory tract (nasopharynx). The nares (nostrils) are always heavily colonized, predominantly with Staphylococcus epidermidis and corynebacteria, and often (in about 20% of the general population) with Staphylococcus aureus, this being the main carrier site of this important pathogen. The healthy sinuses, in contrast are sterile.  The pharynx (throat) is normally colonized by  streptococci and various Gram-negative cocci. Sometimes pathogens such as Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and Neisseria meningitidis colonize the pharynx.

5) Violent coughing:

The healthy human mouth is home to a tremendous variety of microbes including viruses, fungi, protozoa and bacteria. The bacteria are the most numerous. Sputum is material coughed up from the lungs and expectorated (spit out) through the mouth. A sputum culture is done to find and identify the microorganism causing an infection of the lower respiratory tract (an infection of the lung). If a microorganism is found, more testing is done to determine which antibiotics will be effective in treating the infection.

Conclusion 

Microorganisms are bacteria,fungi, algae,virus and protozoa. These types of microorganisms can be found in air and also from all living things such as humans and animals whenever there are rich in nutrient or good condition for them to growth.

References 

1)http://en.wikipedia.org/wiki/Algae 

2)http://en.wikipedia.org/wiki/Virus

3)http://en.wikipedia.org/wiki/Fungus

4)http://en.wikipedia.org/wiki/Protozoa

5)http://en.wikipedia.org/wiki/Bacteria

6) http://microbewiki.kenyon.edu/index.php/Human_Hands_and_Fingernails

7)http://www.biology.ed.ac.uk/archive/jdeacon/microbes/airborne.htm

8)http://medical-dictionary.thefreedictionary.com/Sputum+culture

9)http://www.safewater.org/PDFS/resourcesknowthefacts/Disease_Causing_Micro_Org.pdf