Introduction to Bacteriology and Microbial Cell Structure

Question 1

CLEANING

Answer 1

• Cleaning or (to clean) is the mechanical process
(scrubbing) using soap and water or detergent
and water to remove all visible dirt, debris, and
many disease-causing germs from tools,
implements, and equipment.

Question 2

SANITATION

Answer 2

• To sanitize is a chemical process for reducing the
number of disease-causing germs on cleaned
surfaces to a safe level.

Question 3

DISINFECTION

Answer 3

• To disinfect is a chemical process that uses specific products to destroy harmful organisms (except for bacterial spores) on environmental surfaces.

Question 4

STERILIZATION

Answer 4

• To sterilize is the process that completely

destroys all microbial life, including spores.

Question 5

Bacteriology –

Answer 5

The science that deals with the
study of Micro-organisms called Bacteria.
• The science of bacteria, the causative agents of a
member of infectious diseases

Question 6

TYPES OF BACTERIA

Answer 6

1. Non-Pathogenic

2. Pathogenic

Question 7

NON-PATHOGENIC

Answer 7

Beneficial or harmless; Most Numerous
• Useful functions - decompose refuse, improve
some conditions
• Belong to saprophyte group – require dead matter
for growth (a type of nonpathogenic bacteria that
causes dead organic matter to decay thus helps
enrich the soil.
• Some cultures (acidophilus) are used to make
yogurt and some cheese, bacteria in yeast cause
bread to rise and other bacteria create the alcohol
in wine.
• Stimulates immune response
• Helps metabolize food
• Some cultures are used to produce penicillin
• Special types of milk used for gastrointestinal
disorders
• Protects against infection

Question 8

PATHOGENIC

Answer 8

Pathogenic Bacteria (germs or microbes) are harmful microorganismpokops, and although in the minority, they can cause disease or infection in humans when they invade the body, plant or animal tissue.

Question 9

BLOOD

BORNE PATHOGENS.

Answer 9

Disease-causing bacteria or viruses that are
carried through the body in the blood or bodily
• Fluids like HIV and hepatitis

Question 10

COCCI –

Answer 10

round shaped organism, appear in
groups or singularly. There are 3 forms of cocci
bacteria:
• Staphylococci or Staph
o Pus Forming
o Grow in bunches or clusters like
grapes
o Generally Produce LOCAL INFECTIONS

Question 11

Streptococci

Answer 11

o Pus Forming

o Grow in chains

Question 12

Diplococci

Answer 12

o Grow in PAIRS

o Causes bacterial Pneumonia

Question 13

BACILLA –

Answer 13

short rod-shaped organism (Short,
Thin, Thick)
• most common
• Produce Diseases such as
Influenza(Flu), Tetanus(Lockjaw),
Typhoid Fever, Leprosy, Tuberculosis,
Diphtheria

Question 14

SPIRILLA – Corkscrew or Spiral Shaped

organisms

Answer 14

o Subdivided into many groups
a) Most common – Treponema Pallida
which causes syphilis
b) Borrelia burgdorferi which causes
Lyme disease (caused by ticks)
c) Cholera

Question 15

MOVEMENT OF BACTERIA

Answer 15

Different bacteria move in different ways: either by
self-movement (motility) or by use of flagella or
cilia

Question 16

COCCI BACTERIA are transmitted in the air, in

Answer 16

dust or within the substance in which they settle,

they do not have motility/ self-movement.

Question 17

Bacilli and spirilla are both capable of

movement

Answer 17

use flagella or cilia (slender,

hairlike, whip=-like extensions).

Question 18

how do Flagella and Cilia differ?

Answer 18

Flagella- longer, snake-like

Cilia- small, rowing motion

Question 19

ACTIVE OR VEGETATIVE STATE

Answer 19

Grow and Reproduce
1. Conditions are considered to be favorable for
growth when conditions are: dark, dirty, damp
and warm bacteria will grow and multiply.

Question 20

how long does it take for a typical bacterium to differentiate?

Answer 20

This division happens as often as every 20
minutes. (up to 16 million in ½)
o That is why some bacteria are used
for bio-terrorism because the rate of
reproduction of bacteria is very fast

Question 21

INACTIVE (SPORE FORMING STAGE)

Answer 21

When favorable conditions cease to exist (dry,
bright, clean)
o Bacteria die and/or cease to multiply
o Certain bacilli such as anthrax and
tetanus bacilli coat themselves with a
hard waxy outer covering called a spore
which can withstand long periods of
famine, dryness and unsuitable
temperatures. The spores are not harmed
by disinfectants, extreme heat (water
boils at 212 F., extreme cold (liquid
helium freezes at 507 F., chemicals or
sunlight.

Question 22

What is the only way to kill spores?

Answer 22

Only sterilization can kill

bacterial spores.

Question 23

BACTERIAL INFECTIONS

Answer 23

An INFECTION occurs when body tissues are
invaded by disease-causing Or pathogenic
bacteria.
• There can be no bacterial infection without the
Presence of pathogenic bacteria
Pus is a sign of a bacterial infection. So, if bacteria
are eliminated, then clients cannot become infected

Question 24

How do you know if the infection is of Pseudomonas?

Answer 24

when the pus is blue in color

Question 25

LOCAL INFECTION

Answer 25

• Limited to one area (ex: pimple, abscess and boils). • Staphylococci (staph) most common human bacteria, carried by about 1/3 of the population. Can be picked up on doorknobs and other surfaces, shaking hands and unclean implements. • Responsible for food poisoning and toxic Shock syndrome.

Question 26

GENERAL INFECTION

Answer 26

• Spreads throughout the body through the bloodstream (ex. Blood poisoning and syphilis)

Question 27

what are the various causes of infection?

Answer 27

``` o Unclean hands, instruments, open sores & pus, mouth & nose discharge, using and sharing of towels, drinking cups, uncovered coughing, sneezing, and spitting in public. o Enter the body through the mouth, eyes, nose, breaks or wounds in the skin o Contagious or communicable – Disease spreading from one person to another by direct or indirect contact. § Best control is ISOLATION and HYGIENE ```

Question 28

UNBROKEN SKIN

Answer 28

• First line of defense Healthy person’s body secretions such as perspiration and digestive juices discourage bacterial growth

Question 29

BLOODSTREAM

Answer 29

* White corpuscle to devour bacteria | * Antitoxins to counteract toxins caused by bacteria

Question 30

HUMAN DISEASE CARRIER

Answer 30

• Immune o An individual who is personally immune to disease, yet carries the germ that can infect other people (ex. Typhoid fever)

Question 31

METHODS OF DECONTAMINATION

Answer 31

``` • Method #1 o Cleaning first (sanitation or sanitizing) o Then disinfecting with an appropriate EPA registered disinfectant (most often used is Lysol/chloric oxide/sodium hypochlorite) • Method #2 o Cleaning then sterilization o Sterilization is the process that completely destroys all microbial life, including spores o This method destroys all microbes and spores through heat and pressure in an autoclave ```

Question 32

Wet disinfection containers

Answer 32

A. Barbicide jars • Glass –barbicide disinfectant • Used for combs

Question 33

Disinfection tray

Answer 33

* Hard plastic-barbicide disinfectant | * Used for nail implements

Question 34

Disinfection container

Answer 34

``` • Nonmetal, large, deep enough to keep implements completely submerged • Must have a closeable cover • Ship shape disinfectant • Used for brushes, perm rods, rollers, combs ```

Question 35

DRY DISINFECTION CONTAINER

Answer 35

AIRTIGHT CABINET OR DRAWER THAT HAS A CHEMICAL AGENT IN IT. | • Station with Steri-dry fumigant

Question 36

ULTRAVIOLET RAY DRY DISINFECTION | CONTAINER

Answer 36

``` • Uses UV ray bulbs that have a germicidal effect o Meaning they kill most bacteria and some viruses, o Also dries the implements in it: brushes, rollers, pw rods, combs, etc. ```

Question 37

What are antiseptics?

Answer 37

Are chemical germicides formulated for use on the skin and are registered and regulated by the FDA.

Question 38

which type of antiseptics is less drying to the skin?

Answer 38

Benzalkonium

Question 39

where should you NOT use antiseptics?

Answer 39

Instruments and other surfaces

Question 40

How should one deal with an exposure event?

Answer 40

CONTACT WITH BLOOD OR BODY FLUID • An EXPOSURE INCIDENT is contact with nonintact (broken) skin, blood, body fluids or other potentially infectious materials that is the result of the performance of an employee’s duties. • Never attempt to clean or disinfect any used tool or implement at your workstation. • Proper cleaning and disinfecting should only be accomplished in a specified area of the salon and requires the use of clean, warm running water, a scrub brush, and liquid soap for cleaning and disinfectant solution for disinfecting.

Question 41

Bright-field microscopy

Answer 41

• Differences in the contrast between specimen and surrounding medium

Question 42

Phase-contrast microscopy

Answer 42

• Differences in phases of light depending on the property of structure it passes

Question 43

Darkfield microscopy

Answer 43

• Light reaches the specimen from the sides

Question 44

Fluorescence Microscopy

Answer 44

specimens that are fluorescent

Question 45

Those that do not naturally fluoresce maybe stained with a group of fluorescent dyes called

Answer 45

fluorochromes.

Question 46

Flourosecne Microscopy is used for which microorganism?

Answer 46

Mycobacterium tuberculosis

Question 47

immunofluorescence.

Answer 47

``` In this technique, specific antibodies (eg, antibodies to Legionella pneumophila) are chemically labeled with a fluorochrome such as fluorescein isothiocyanate (FITC) ```

Question 48

Electron microscope

Answer 48

The high resolving power of electron microscopes has enabled scientists to observe the detailed structures of prokaryotic and eukaryotic cells. • The superior resolution of the electron microscope is due to the fact that electrons have a much shorter wavelength than the photons of white light. • An important technique in electron microscopy is the use of “shadowing.”

Question 49

Other important techniques in electron microscopy include the use of ultrathin sections of embedded material

Answer 49

``` A method of freeze-drying specimens that prevents the distortion caused by conventional drying procedures, and the use of negative staining with an electrondense material such as phosphotungstic acid or uranyl salts. o Without these heavy metal salts, there would not be enough contrast to detect the details of the specimen. ```

Question 50

TEM

Answer 50

Response to electrons fired by an electron gun • They give a ray of electrons to the specimen by firing it with an electron gun and they will see the response • Was the first to be developed • Uses a beam of electrons focused by an electromagnetic condenser lens onto a thin specimen.

Question 51

What is the resolving power of TEM microscopy?

Answer 51

TEM can resolve particles 0.001 μm apart. Viruses with diameters of 0.01–0.2 μm can be easily resolved.

Question 52

What are classified as Gram-positive and Gram-negative?

Answer 52

Most bacteria are classified as gram-positive or gram negative according to their response to the Gram staining procedure. • This procedure was named for the histologist Hans Christian Gram, who developed this differential staining procedure in an attempt to stain bacteria in infected tissues. • The Gram stain depends on the ability of certain bacteria (the gram-positive bacteria) to retain a complex of crystal violet (a purple dye) and iodine after a brief wash with alcohol or acetone

Question 53

Gram-Positive

Answer 53

``` • Thick layer (20-80nm) • Main composition: o Teichoic, teichuronic acids that hold layers together (50% dry weight of wall, 10% of the cell) § The teichoic acids constitute major surface antigens of those gram-positive species that possess them, and their accessibility to antibodies has been taken as evidence that they lie on the outside surface of the peptidoglycan. § In the pneumococcus (Streptococcus pneumonia), the teichoic acids bear the antigenic determinants called Forssman antigen. ```

Question 54

Gram-negative

Answer 54

``` • Thin layer (2nm) o Outer membrane (bilayered structure, inner part similar with cell membrane, outer part has lipopolysaccharide (LPS)) o What is unique is that it has lipopolysaccharide on the outer part o The ability of the outer membrane to exclude hydrophobic molecules is an unusual feature among biologic membranes and serves to protect the cell (in the case of enteric bacteria) from deleterious substances such as bile salts. Because of its lipid nature, the outer membrane would be expected to exclude hydrophilic molecules as well. ```

Question 55

Porins

Answer 55

``` o special channels capable of doing passive diffusion of LMW hydrophilic compounds o Large antibiotic molecules penetrate the outer membrane relatively slowly, which accounts for the relatively high antibiotic resistance of gram-negative bacteria. ```

Question 56

Special molecule LPS

Answer 56

``` o Made up of lipid A and core o Antigenic site, endotoxin o LPS is synthesized on the cytoplasmic membrane and transported to its final exterior position. o The presence of LPS is required for the function of many outer membranes proteins. ```

Question 57

What is the toxigenic determinant of G -ve?

Answer 57

Lipopolysaccharide is a toxigenic determinant of gram-negative

Question 58

Lipoprotein

Answer 58

``` o Combination of lipid and protein o Stabilizes outer membrane o Lipoprotein is numerically the most abundant protein of gram-negative cells (ca 700,000 molecules per cell) ```

Question 59

MYCOBATERIUM TUBERCULOSIS

Answer 59

``` Cell wall with large amount of waxes, resistant to harsh chemicals (mycolic acid) • Acid fast bacilli o Cannot be reacted upon by the normal gram stain, you have to use other components o Dye introduced into these cells by heating or treatment with detergent, cannot be removed by dilute HCL ```

Question 60

site of action of penicillin

Answer 60

``` o Acts on the cell wall; that’s why some bacteria don’t have a cell wall so that antimicrobial agents cannot act on them, that’s the defense mechanism of the bacteria ```

Question 61

example of a wall-less bacterium

Answer 61

pneumococcus, Neisseria, Anthrax