lab report 4 from soo teng

Name       :Chai Soo Teng
Matric No:111356

Lab 4:Sources of Contamination and Infection

Introduction:
       Airborne microorganisms are usually carried on dust particles,although some(fungal spores,for example)ay be carried directly by air currents.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 ehich are vital to our wellbeing,constitute our resident or normal microflora.Resident microorganisms are nourished by the chemicals and moisture excretedby the human bod.In moist areas such as the armpit,there may be one million bacteria per cm³;on the drier skin of the forearm,there may be 10000 bacteria per cm³!!!
      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 pathogenswhich 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 condition 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 largely consists of nonpathogens or opportunistic pathogens.
       Large number of transients enter the upper respiratory tract as we breathe or eat.They may also come from our own hands 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

Result: 
                                                             Colonies of air

 

Colonies of normal breathing

   

Colonies of  violent coughing

                                                                
                                                                                     Colonies of ear

                                                                                   Colonies of hand

Discussion:
1.Microbes found in air
   In additional to gases,dust particle and water vapour,air also contain vegetative cells and spores of   bacteria,fungi and algae,viruses and protozoa.

2.Microbes found in normal breathing 

   There are hundreds of bacteria living in human mouth.Although most of these bacteria are non-pathogenic, some may induce illness if they successfully break through the bodies defense systems. Some examples of these non-pathogenic bacteria are Streptococcus, Neisseria, Haemophilus, and Micrococcus. Some of the pathogenic examples include Staphylococcus aureus, Corynebacterium diphtheriae, Streptococcus pneumoniae, and Haemophilus influenzae among others.

3.Microbes found in violent coughing

Coughing usually means there is something in the respiratory passages that should not be there. Bacterial pneumonia is an infection caused by the presence of bacteria within the lungs. The most common cause of this type of infection is a bacterium called Streptococcus pneumonia.

4.Microbes in ear
 Healthy outer ear are houses a variety of microbes. Some of the most common bacteria are Staphylococcus epidermis, Turicellaotitidis, Alloiococousotitis, Pseudomonas aeruginosa, Corynebacterium, Staphylococcus aureus, and Streptococcus saprophyticum. The most common fungal microbe known to reside in the ear is Candida albicans .Microbes that are known to inhabit the middle ear are Streptococci, Haemophilus pneumoniae, Moraxella catarrhalis, and less commonly Mycobacterium.Because of the blood-labyrinth barrier and the presence of immunoglobulins in the inner ear fluids there should be virtually no microbes living normally in the inner ear.

5.Microbes in hand  

The hands and fingernails are often affected by fungal and yeast infections, such as those caused by species of Trichophyton and Candida.There are many species within these genera that can be located within the fingernails, such as Staphylococcus epidermis and aeureas or Candida albicans, parapsilosis, and instaniae.

Conclusion:
Microorganisms is suitable to survive and grow in a medium that rich in nutrient.Except for the nutrient,the pH and the temperature also will affect the growing of the microorganisms.Through the experiment,we can be seen that various microorganisms are present in the air and human's bodies.

References:
 http://microbewiki.kenyon.edu/index.php/Human_Hands_and_Fingernails

faculty.ksu.edu.sa/18698/346/Microorganisms%20in%20Air.ppt

http://microbewiki.kenyon.edu/index.php/Nasal_passageway#Which_microbes_are_present_in_the_Nasal_Passageway.3F

http://www.livestrong.com/cough-bacteria/

http://www.netdoctor.co.uk/health_advice/facts/cough.htm

http://microbewiki.kenyon.edu/index.php/Ear