Introduction to Microbiology

Introduction to Microbiology

• Microbiology is derived from the Greek words micros (small), bios (life), and logos (study).
• Microbiology is the science which studies microorganisms, microscopic living organisms.
• Microorganisms are less than 1 millimeter in diameter and cannot be seen by the naked eye.
• Microorganisms can be viewed through microscopes and they can exist as single cells or clusters.
• Microorganisms include cellular organisms like bacteria, archaea, fungi, algae, and protozoa.
• Viruses and bacteriophages are also included as microorganisms, but they are acellular.

Sub-Disciplines of Microbiology

• Bacteriology studies bacteria.
• Virology studies viruses.
• Protozoology studies protozoa.
• Immunology studies immunity.
• Mycology studies fungi.
• Phycology studies algae.

Terminology

• A pathogen is an organism that causes disease.
• A parasite lives on or in another species, obtaining food and shelter while harming the host.
• A saprophyte lives on or derives food from dead organic matter, e.g., fungi.
• Normal flora are microbes that live in or on another creature, benefiting each other in normal conditions.
• A vector is an organism which transfers a pathogen to a person, can be either mechanical or biological, such as insects or ticks.
• Infection involves the entry of a microorganism, especially a pathogen into the body.
• The incubation period is the period of proliferation of microorganisms after their entry into a body, but before signs and symptoms are apparent.
• The prodromal period is the interval between the onset of symptoms of an infectious disease and the appearance of characteristic manifestations.
• Prognosis is the prediction of the course of a disease.
• Epidemiology studies the occurrence of a disease, including how, when, and where it occurs and how it is transmitted.
• An epidemic disease is an unusual and sudden outbreak of a disease, like cholera, in a region or country.
• An endemic disease is usually found in a particular area, such as typhoid.
• A pandemic disease is an epidemic that occurs worldwide, such as the Corona Virus.
• A sporadic disease is found here and there at intervals, such as TB.
• Isolation involves separating infected persons for a period of communicability of the disease.
• Quarantine is the limitation of movement of a person or animal that has been exposed to an infectious disease for the duration of the maximum incubation period.
• Inflammation is the response of the body to infection or injury, characterized by swelling, heat, redness, and pain.
• Pathogenicity is the ability of an organism to cause disease.
• Virulence is the degree or intensity level of a pathogen.
• A toxin is a poisonous substance produced by a living organism.
• A toxicant is a poisonous substance prepared by man.
• An antigen is any substance, usually a protein, that stimulates the immune response.
• An antibody is a protein that is formed as a result of the immune response to an antigen.
• Sterilization is the process by which all forms of life are killed.
• A bactericide is a substance or agent that kills bacteria.
• A disinfectant is an agent that kills microorganisms by applying to inanimate (non-living) objects.
• An antiseptic is an agent that kills microorganisms by applying to living things.
• A vaccine consists of attenuated or killed microbes or inactivated toxins to induce immunity.
• Vaccination is the process of inducing immunity by administering a vaccine.
• Fomites are inanimate objects or materials used by an infected patient that may transfer the infection via contact, such as clothing or other utensils.
• A eukaryotic cell is a complete cell having a well-defined nucleus and other membranous structures, e.g., multicellular and unicellular organisms.
• A prokaryotic cell is an incomplete cell having no well-defined nucleus and other membranous structures, and are always unicellular, e.g., bacteria.
• Bacteria are prokaryotic microorganisms which cannot be seen with the naked eye.
• A virus is a minute microorganism which shows characteristics of both living and non-living things, and are obligatory parasites.
• Protozoa are microscopic single-celled eukaryotic microbes that can be pathogenic or non-pathogenic.

Importance of Microbiology in Nursing

• Microbiology is vital for nursing students.
• Nurses manage all aspects of patient health and infection control in hospitals.
• Nurses must know microbiology to care for patients and protect themselves from pathogenic microorganisms.
• Medical microbiology students need to know about bacteria that cause human illnesses.
• Medical microbiology students need to understand the diseases that illnesses cause.
• Medical microbiology students need to understand how to diagnose, prevent, and treat those diseases.

Role of Nurses in Different Units

• Nurses prevent the spread of infection.
• Nurses maintain sterile fields.
• Nurses collect specimens.
• Nurses implement immunization schedules in hospitals.
• Nurses implement microbiology in different units.
• Nurses work in burns units, operation theaters, obstetric units, and intensive care nurseries.
• Nurses dispose of biomedical waste.

Preventing the Spread of Infection

• Infections propagate in different ways and nurses must be aware of these ways.
• Infections spread by contact (touch), air (airborne), droplets (sneezing, coughing), contaminated food and drink (foodborne), sexual contact, and infected blood transfusion.
• Nurses utilize this knowledge to identify specialized infection control measures.
• Nurses prevent infections by understanding how disease-causing organisms enter, exit, and spread from one individual to another in hospitals and communities.
• Diseases such as cholera, common cold, chicken pox, and TB provide examples.
• A person suffering from a common cold sneezes and expels fine droplets carrying thousands of viruses into the air.
• The virus may enter the body of a healthy person when they are breathing.

Maintaining a Sterile Field

• Sterile fields must be established and maintained in hospitals using microbiology techniques.
• Nurses need to be familiar with microbiology techniques.
• Nurses must understand how to create and maintain sterile fields in operating rooms, to prevent infection following surgery.
• Hand washing is crucial before and after surgeries.
• Hand washing minimizes microorganisms on hands to reduce the risk of hospital-acquired infection.
• Nurses apply microbiology knowledge to use sterile equipment, which is necessary for invasive procedures.
• Nurses should understand the sterilization process.

Role in Collecting Specimens

• Nursing practitioners must understand the importance of properly collecting specimens for bacteriological testing.
• Correct collection yields reliable results.
• Practitioners must be familiar with infectious diseases and their mode of infection.
• Properly collected specimens are crucial for bacteriological analysis to obtain reliable results.
• Collecting a clinical specimen from the appropriate site of infection is necessary to identify the organism responsible for an infection.

Implementing Immunization Schedules

• Nurses play a role in preventing diseases through patient immunization and prevention of other diseases such as diphtheria and MMR.
• Nurses should be knowledgeable about vaccine schedules and how vaccines are transported from production to administration via a cold chain.
• Microbiology is a subset of immunology that can assist nurses.
• Nurses who know immunology are well prepared for vaccines and effectively use the cold chain for vaccination and vaccine protection.

Applying Microbiology in Nursing units

• Areas discussed in health care settings relate to microbiology's role as a nursing specialty.
• Patients with contagious or infectious diseases are hospitalized in contagious or infectious wards.
• Careful precautions in rabies wards or gastroenteritis wards prevent infection spreading.
• Nurses employ aseptic procedures when caring for patients.
• In burns units, while a burn wound is initially sterile, microorganisms rapidly colonize it.
• Nurses prevent infection by aseptic techniques and sterile equipment.
• Before operations, nurses ensure operation theaters are free of microorganisms through fumigation.
• Nurses ensure all procedures are done under sterile conditions.
• Swabs are cultured from various locations in the operation theater to determine sterility; therefore, it is critical to conduct procedures under sterile conditions.
• Obstetric Units: Wound infection of the birth canal after childbirth or abortion causes maternal mortality.
• Nurses play roles during antenatal care, childbirth, and the six-week postpartum period.
• Intensive care nurseries employ experienced staff with knowledge of incubators, feeding methods, respirators, and catheters for infants.
• Nurses maintain sterile atmospheres in these nurseries.

Disposing of Biomedical Waste

• There must be an appropriate disposal method for biomedical waste based upon microbiology principles.
• Nurses are knowledgable about the processes for creating and maintaining sterile fields by using microbiological expertise.
• Biomedical waste must be disposed of and improperly disposed waste may result in a disease outbreak.
• Proper disposal of biomedical waste requires knowledge of microbiology principles.