Human & microbial interaction

Date:6/3/2021 www. qadricohs.edu.pk FB Page: Qadri College of Health Sciences, Karachi, Sindh, Pakistan. 1
QADRI COLLEGE OF HEALTH SCIENCES, KARACHI
U-4, 1 OF 2
“HUMAN AND MICROBIAL INTERACTION”
By: Aftab H. Abbasi
RN, DCHN, BSN, MA, LL.B
Lecturer Nursing
Qadri College of Health Sciences Karachi

- In this unit learners will learn about the
beneficial and harmful role of
microorganisms.
- They will also learn about some diseases
caused by these microorganisms.

At the completion of this unit learners will be
able to:
1- Define Normal flora of the body.
2- Differentiate between resident and transient normal flora.
3- List at least three beneficial role of Normal flora.
4- Define Nosocomial Infections.
5- List at least three measures to control nosocomial infections.
6- Describe some pathogenic microbes and diseases,
i.e. Tetanus, Typhoid, Cholera, Diphtheria, Tuberculosis,
Pertusis, Mumps, Measles, Polio, Influenza, Ascariasis,
Taeniasis and dermatomycosis.

NORMAL FLORA OF THE HUMAN BODY
Human microbiome:
The human microbiome (or human micro biota) is the
aggregate of microorganisms that reside on the surface and in
deep layers of skin, in the saliva and oral mucosa, in the
conjunctiva, and in the gastrointestinal tracts.
They include bacteria, fungi. Some of these organisms perform
tasks that are useful for the human host.
However, the majority have no known beneficial or harmful
effect.
Those that are expected to be present, and that under normal
circumstances do not cause disease, but instead participate in
maintaining health, are deemed members of the normal flora.

NORMAL FLORA OF THE HUMAN BODY
Definition: Normal flora are the microorganisms
that live on another living organism (human or
animal) or inanimate ( ‫بے‬
‫جان‬ ) object without causing
disease.
The composition of the normal flora changes with
age, sex, diet, development and environment.
Normal flora may aid the host in several ways:
- Aid in digestion of food.
- Help the development of mucosa immunity.
- Protect the host from colonization with
pathogenic microbes.

DIFFERENCE BETWEEN RESIDENT AND TRANSIENT NORMAL FLORA
(Resident) Normal flora: are microorganisms
that are always present on or in a person.
Resident flora are life-long members present at
certain anatomical sites.
(Transient) Normal flora: are microorganisms
that colonize people for hours to weeks but do
not establish themselves permanently.
Transient microbes are unable to colonize the
body for longer periods.

DIFFERENCE BETWEEN RESIDENT AND TRANSIENT NORMAL FLORA

BENEFICIAL ROLE OF NORMAL FLORA
1.Provide a first line of defense against
microbial pathogens through “bacterial
interference”.
2.Assist in digestion: They produce vitamin B
and vitamin K in intestine.
3.Play a role in toxin degradation.
4.The oral flora contribute to immunity by
inducing low levels of circulating and
secretory antibodies that may cross react
with pathogens.

BENEFICIAL ROLE OF NORMAL FLORA
5. The microbiota affect carcinogenesis in
three broad ways:
(i) altering the balance of tumor cell
proliferation and death.
(ii) regulating immune system function .
(iii) influencing metabolism of host-produced
factors, foods and pharmaceuticals
such as : Lactobacillus and
Bifidobacteria, are known to prevent
tumor formation.

NOSOCOMIAL INFECTIONS
Nosocomial infection or Healthcare-associated infections (HAI)
Nosocomial also Called HOSPITAL ACQUIRED INFECTION
Nosocomial infection comes from Greek words:
"nosus" = disease. "komeion" = to take care of.
DEFINITION (WHO):
- An infection acquired in hospital by a patient who was
admitted for a reason other than that infection.
- An infection occurring in a patient in a hospital or other health
care facility in whom the infection was not present or
incubating at the time of admission.
- This includes infections acquired in the hospital but appearing
after discharge & also occupational infections among staff of
the facility.

THE HISTORY OF HAI’S
Hippocrates (medical practitioner) made the relatively profound
statement “Primum non nocere”
that - If you wish to become a physician, always
follow the maxim, first do no harm.
Nearer to the present day, Florence Nightingale
paraphrased Hippocrates’ words with the
phrase “It may seem a strange principle to
enunciate as the very first requirement in a
hospital that it should do the sick no harm”.

TYPES OF INFECTIONS
- Urinary tract infections (UTI).
- Surgical wound infections (SWI).
- Lower respiratory infections.
- Traumatic wounds and burns infections.
- Primary bacteremia.
- Gastrointestinal tract.
- Central nervous system.
MODE OF TRANSMISSION:
- Contact/hand borne (most common)
- Aerial route or air borne
- Oral route
- Parenteral route
- Vector borne

SPREAD - ENTRY AND EXIT ROUTES
1- Natural orifices - mouth, nose, ear, eye,
urethra, vagina, rectum.
2- Artificial orifices - such as tracheostomy,
ileostomy, colostomy.
3- Mucous membranes - which line most
natural and artificial orifices.
4- Skin breaks - either as a result of accidental
damage or deliberate inoculation/incision.

PEOPLE DON’T REALIZE WHEN THEY HAVE MICROBES ON THEIR HANDS
Healthcare workers can get 100s to 1000s of
bacteria on their hands by doing simple
tasks like:
• pulling patients up in bed.
• taking a blood pressure or pulse.
• touching a patient’s hand.
• rolling patients over in bed.
• touching the patient’s gown or bed sheets.
• touching equipment like bedside rails,
overbed tables, IV pumps.

CHAIN OF INFECTION
1- Source/reservoir of micro-organisms:
• infected person [host] or other source.
2- Method of transmission:
• hands, instruments, clothing, coughing,
sneezing, dust etc.
3- Point of entry:
• orifices, mucous membranes, skin.
4- Susceptible host:
• low resistance to infection.

MEASURES TO PREVENT AND CONTROL NOSOCOMIAL INFECTIONS
1- Treat ALL patients as a potential
biohazard.
2- ISOLATION: Designed to prevent
transmission of microorganisms by
common routes in hospitals.
3- Sterilization: of all reusable
equipment's such as ventilator,
humidifier and any device that come in
contact with the respiratory tract.

4-

5- Adopt universal routine safe infection
control practices to protect patients,
self and colleagues from infection.

UNIVERSAL PRECAUTIONS
• Hand washing
• Personal protective equipment [PPE]
• Preventing/managing sharps injuries
• Aseptic technique
• Isolation
• Staff health
• Linen handling and disposal
• Waste disposal
• Spillages of body fluids
• Environmental cleaning
• Risk management/assessment

PERSONAL PROTECTIVE EQUIPMENT
PPE when contamination or
splashing with blood or
body fluids is anticipated:
• Disposable gloves
• Plastic aprons
• Face masks
• Safety glasses, goggles,
visors
• Head protection
• Foot protection
• Fluid repellent gowns

REMEMBER:
EVERYTHING YOU TOUCH
HAS BEEN TOUCHED BY
SOMEONE ELSE.
IN SPITE MANY DEVELOPMENTS IN MEDICINE AND ASEPSIS HAND
WASHING STILL THE BEST SOLUTION
Hand hygiene is the simplest,
most effective measure for
preventing hospital-acquired
infections.

Methods to control Microbial Growth

By: Aftab H. Abbasi
RN, DCHN, BSN, MA, LL.B
Lecturer Nursing
Qadri College of Health Sciences Karachi

Human & microbial interaction

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Human & microbial interaction

Similar to Human & microbial interaction (20)

Recently uploaded

Recently uploaded (20)

Human & microbial interaction