Microbiology - Ch 13 (Microbe-Human interaction Infection and Disease)
drinking glasses, toothbrushes, toys, punctures, droplets, doorknobs, pens = formites (inanimate objects
Indirect contact - (CONTACT TRANSMISSION)
a condition in which pathogenic microorganisms penetrate the host defenses, enter tissues and multiply ( would not feel until progress to next stage, which is disease stage)
Infection
• Uterus and contents are normally sterile and remain so until just before birth • Breaking of fetal membrane exposes the infant; all subsequent handling and feeding continue to introduce what will be normal flora • In utero = sterile environment, once out of the uterus it is exposed to flora.
Initial Colonization of the Newborn
enter via respiratory droplets into oral and nasal cavities
Respiratory tract
those with active diseases and asymptomatic (carriers) - will only live in humans, only found in humans, only grows in humans
Human reservoirs
enter via nicks, abrasions, punctures, incisions
Skin
are microbial poisons that aid establishment and progress of disease
Toxins
microbes that occupy the body for only short periods (they are there for a short period of time then leaves)
Transients (normal flora)
influenced by hygiene
Transients: ( 2 cutaneous populations)
some pathogen have the ability to move from mother's bloodstream and into baby's bloodstream via the placenta (can pass from babys bloodstream - via: bacteria)
Transplacental
patient's immune system begins to overcome the microbe, symptoms begin to fade, patent's strength returns and the body system comes back to normal - immune system begins to kill microbe, pt starts feeling better, recovery begins
convalescent period
dissolve kratin of skin or hair
keratinase - (exoenzyme)
Bacterial flora benefit host by preventing overgrowth of harmful microbes - (flora on body either work together or doesn't work together)
microbial antagonism (resident flora)
dissolve mucus coating
mucinase - (exoenzyme)
Microbes that engage in mutual or commensal associations - microbiota
normal flora (indigenous flora)
one that invades the tissues when the body defenses are suppressed
opportunistic pathogen
an epidemic is spread across continents. Ex: very contagious disease like FLU. Numbers are beyond the amnt we usually see.
pandemic
any agent capable of causing disease in a healthy person with normal immune defenses (being @ hospital, being more @ risk for disease to occur)
pathogen (true)
microbe multiplies at highest rate, exhibits greatest toxicity and is well established in target tissue; marked by classic symptoms of particular disease characteristics -- Sx of disease. Can tell more which type of disease it is.
period of invasion
initial infection
primary infection
earliest symptoms (generalized symptoms) of infection; include: head ache, fatigue, nausea, fever, muscle aches (1-2 days) -- generic type Sx appear. Still cant tell what infection is.
prodromal stage
the degree of pathogenicity of a parasite
virulence
Flora found in upper respiratory • Oral cavity, nasal cavity pharyngeal, epiglottis, larynx, trachea ** Nasal cavity = __1__ ** Oral cavity = __2__
1. Streptococcus Aureus 2. Staphylococcus Aureus
Flora of the Genitourinary Tract Sites that harbor microflora (locations where we can find Normal Flora in female & male genitilia) • Females = __1__ • Males - __2__
1. Vagina, distal urethra, and external genitalia 2. Distal urethra, external genitalia
Name the 3 types of VEHICLE TRANSMISSION
1. AIRBORNE 2. WATERBORNE 3. FOODBORNE
Name the different types of MECHANISMS of INVASION & ESTABLISHMENT OF PATHOGENS
1. ATTACHING TO THE HOST 2. TISSUE PENETRATION 3. BACTERIAL TOXINS: a potent source of cellular damage 4. SURVIVING HOST DEFENSES 5. ANTIBIOTIC RESISTANCE
Vehicle Transmission -- substances that can harbor a microbe for a short time, not long / microbe doesn't like to stay here permanently 1. __?__- dust particles 2. __?__- streams, standing water, swimming pools, water supply 3. __?__- meats, prepared foods
1. Airborne 2. Waterborne 3. Foodborne
Name the areas of the LOWER RESP TRACT . In which it is considered STERILE.
1. BRONCHI 2. BRONCHIOLES 3. LUNGS
Name the the 3 types of ways a disease can be transeferred.
1. CONTACT 2. VEHICLE 3. VECTOR
1. What does CDC stand for? 2. What does WHO stand for?
1. Center for Disease Control 2. World Health Organization
Name the 2 different types of CONTACT TRANSMISSION
1. Direct Contact 2. Indirect Contact
We Are Not Alone • The human body exists in a state of dynamic __1__ • Many interactions between human body and microorganisms involve the development of __2__ • Colonization of the body involves a constant "give and take"
1. Equilibrium 2. Biofilms
Name examples of ADHESION
1. Fimbrae 2. Flagella 3. Glycocalyx 4. Cilia 5. Suckers 6. Hooks 7. Barbs 8. Spikes
Name the 2 types of VECTOR TRANSMISSIONS
1. MECHANICAL VECTOR 2. BIOLOGICAL VECTOR
NAME examples of an EXOENZYME
1. MUCINASE 2. KERATINASE 3. COLAGENASE 4. HYALURONIDASE
Oral cavity, large intestine, and rectum harbor appreciable flora o Flora of the __1__ • Most diverse and unique flora of the body • Numerous adaptive niches • Bacterial count of saliva (5 x 109 cells per milliliter) o Flora of the __2__ • Has complex and profound interactions with host • 108-1011 microbes per gram of feces • Intestinal environment favors anaerobic bacteria • Intestinal bacteria contribute to intestinal odor & flatulence
1. Mouth 2. Large Intestine
STAPH is found in __1__ cavity STREP is found in __2__ cavity
1. NASAL 2. ORAL
Name the areas of the UPPER RESP TRACT . In which NORMAL FLORA is found in.
1. ORAL CAVITY 2. NASAL CAVITY 3. PHARYNGEAL 4. EPIGLOTTIS 5. LARYNX 6. TRACHEA
Name the ROUTE of PATHOGEN takes in the correct order
1. Portal of Entry 2. Requirement for an Infectiuos Dieseas (ID) 3. Mechanism of invasion and establishment of the pathogen 4. Establishment in target organ 5. Portal of Exit
Name the portal of exits
1. Respiratory & salivary (resp doplets) 2. Skin scales 3. Urogenital 4. Blood
exotoxin - protein secreted that goes to site of action = target tissue - produced by gram positive and gram negative - very powerful and deadly can be classified by target tissue: __1__ - lyse blood cells __2__ - affect intestinal mucosa __3__ - affect nerve tissue __4__ - affect general tissue
1. hemotoxins 2. Enterotoxins 3. Neurotoxins 4. cytotoxins
Requirement for an Infectious Dose (ID) • infectious dose - Minimum number of microbes required for infection to proceed • Microbes with small IDs have greater virulence • Lack of ID will__1__ - has to have a big # or WILL NOT cause disease
1. not result in infection
develops rapidly and lasts a short time
Acute disease
microbes gain a stable foothold at the portal of entry; dependent on binding between specific molecules on host and pathogen some ex: fimbrae, flagella, glycocalyx, etc
Adhesion
diseases that naturally occur in animals and are spread to humans are called zoonoses (EX: RABIES)
Animal reservoirs
• Enzyme that they can produce that digests antibiotics • Genes the microbe possesses that allow it to avoid destruction by an antibiotic will add to its virulence
Antibiotic resistance
used to avoid phagocytosis - poison to leukocytes
Antiphagocytic factors -(surviving host defenses)
lacking the ability to cause disease
Avirulent
infects the bug, bug bites human = fleas, mosquiots & ticks
Biological Vector - (vector transmission)
develops slowly with less sever symptoms that are continual or recurrent
Chronic disease
when an infected host can transmit the infectious agent to another host and establish infection in that host -- contagious between humans
Communicable disease -
1. Direct contact - handshaking, kissing, sex, bites 2. Indirect contact - drinking glasses, toothbrushes, toys, punctures, droplets, doorknobs, pens = formites (inanimate objects)
Contact Transmission
a communicable disease that is easily transmitted
Contagious disease
handshaking, kissing, sex, bites
Direct contact - (CONTACT TRANSMISSION)
a deviation from health due malfunction of a tissue or organ caused by microbes or their products
Disease
enter via food, drink, and other ingested materials
Gastrointestinal tract
This is only released when microbe is damaged and is falling apart
ENDOTOXIN
produced by gram positive and gram negative - very powerful and deadly
EXOTOXIN
Name the 2 types of TOXINS
EXOTOXIN ENDOTOXIN
occur when normal flora is introduced to a site that was previously sterile (if gets a chance to overgrow, then it can cause disease to grow / occur)
Endogenous infections (resident flora)
the study of frequency and distribution of disease and other health-related factors in defined human populations. Epidemiologists are interested in surveillance that involves collecting analyzing and reporting data on the rates of occurrence, mortality, morbidity, and transmission of infections. Some diseases are reportable or notifiable. The Role of the CDC (Center for Disease Control) and WHO (World Health Organization), as well as city, county and state agencies.
Epidemiology
aided by virulence factors, microbes settle in their target organ of choice and continue to cause damage at the site.
Establishment in target organ
Name the 2 PRIMARY examples of MECHANICAL VECTOR?
FLIES & ROACHES
*GI tract is a long hollow tube, bounded by mucous membranes - Tube is exposed to the environment (since its open, it is exposed to Normal Flora) ***Variations in flora distribution due to shifting conditions (pH, oxygen tension, anatomy)*** * Oral cavity, large intestine, and rectum harbor appreciable flora o Flora of the Mouth - Most diverse and unique flora of the body - Numerous adaptive niches - Bacterial count of saliva (5 x 109 cells per milliliter) o Flora of the Large Intestine - Has complex and profound interactions with host - 108-1011 microbes per gram of feces - Intestinal environment favors anaerobic bacteria - Intestinal bacteria contribute to intestinal odor & flatulence
Flora of the Gastrointestinal Tract
Sites that harbor microflora (locations where we can find Normal Flora in female & male genitilia) • Females - Vagina, distal urethra, and external genitalia • Males - Distal urethra, external genitalia
Flora of the Genitourinary Tract
- Flora found in upper respiratory • Oral cavity, nasal cavity pharyngeal, epiglottis, larynx, trachea • Oral cavity - Streptococcus Aureus • Nasal cavity - Staphylococcus Aureus ** STAPH in Nasal ** STREP in Oral - Lower respiratory sterile • Bronchi, bronchioles, lungs
Flora of the Respiratory Tract
- Skin is the largest and most accessible organ - Two cutaneous populations • Transients: influenced by hygiene • Residents: stable, predictable
Flora of the Skin
__?__ is a long hollow tube, bounded by mucous membranes • Tube is exposed to the environment (since its open, it is exposed to Normal Flora)
GI tract
microbe confined to specific tissue
Localized infection
microbes that become established
Residents (normal flora)
stable, predictable - less influenced by hygiene
Residents: ( 2 cutaneous populations)
dissolve collagen
collagenase - (exoenzyme)
does not infect bug, carried on bodies of bug = flies & roaches
Mechanical Vector - (vector transmission)
• These depend on the genes that a microbe has to produce his weapons (protein products) • Severity of the disease depends on the virulence of the pathogen • Virulence factors - traits used to invade and establish themselves in the host, also determine the degree of tissue damage that occurs - severity of disease
Mechanism of invasion and establishment of the pathogen
several agents establish a simultaneous infection
Mixed infection
a. Contact Transmission 1. Direct contact - handshaking, kissing, sex, bites 2. Indirect contact - drinking glasses, toothbrushes, toys, punctures, droplets, doorknobs, pens = formites (inanimate objects) b. Vehicle Transmission -- substances that can harbor a microbe for a short time, not long / microbe doesn't like to stay here permanantly 1. Airborne - dust particles 2. Waterborne - streams, standing water, swimming pools, water supply 3. Foodborne - meats, prepared foods c. Vector Transmission 1. Mechanical Vector - does not infect bug, carried on bodies of bug = flies & roaches 2. Biological Vector - infects the bug, bug bites human = fleas, mosquiots & ticks
Modes of Infectious Disease Transmission - how diseases transport themselves
a disease that arises from environmental microbes or normal flora - disease that cannot spread from human human
Noncommunicable disease
soil, water, food (live in food, water & soil - ex: e. coli)
Nonliving reservoirs
• Most areas of the body in contact with the outside environment harbor resident microbes • Internal organs, tissues, and fluids are microbe-free • Transients - microbes that occupy the body for only short periods (they are there for a short period of time then leaves) • Residents - microbes that become established
Normal Flora
infectious diseases acquired as a result of a hospital stay. MOST COMMON MICROBES: • E. coli • Staphylococcus • Klebsiella • Pseudomonas • Streptococcus • Enterococcus • Candida
Nosocomial infections
Where is MOST of our FLORA seen in out GI tract ?
ORAL CAVITY & LI
• endemic occurrence - disease exhibits a relatively steady frequency over a long time period in a particular geographic locale. • sporadic - disease is occurs as occasional cases at irregular intervals in unpredictable locales. (ex: tetanus, rabies) • epidemic - a disease is increasing beyond what is expected for that population. • pandemic - an epidemic is spread across continents. Ex: very contagious disease like FLU. Numbers are beyond the amnt we usually see.
Patterns of occurrence
site at which the parasite enters the host, most microbes are adapted to a specific portal (otherwise cannot infect).
Portal of Entry
site at which the parasite enters the host, most microbes are adapted to a specific portal (otherwise cannot infect). exogenous - source OUTSIDE the body endogenous - source on or INSIDE the body
Portal of Entry
pathogens depart by a specific avenue many times the same as the entry Portals include: - Respiratory & salivary (resp doplets) - Skin scales - Urogenital - Blood
Portal of Exit
• infectious dose - Minimum number of microbes required for infection to proceed • Microbes with small IDs have greater virulence • Lack of ID will not result in infection - has to have a big # or WILL NOT cause disease
Requirement for an Infectious Dose (ID)
the primary habitat where the pathogen is maintained as a source of the infection
Reservoir
Microbes have a permanent place to reside so that they can continue to exist and be spread.
Reservoirs
• Bacterial flora benefit host by preventing overgrowth of harmful microbes - microbial antagonism (flora on body either work together or doesn't work together) • Endogenous infections - occur when normal flora is introduced to a site that was previously sterile (if gets a chance to overgrow, then it can cause disease to grow / occur)
Resident Flora
Initial Colonization of the Newborn • Uterus and contents are normally __1__and remain so until just before birth • Breaking of fetal membrane exposes the infant; all subsequent handling and feeding continue to introduce what will be normal flora • In utero = #1 environment, once out of the uterus it is exposed to flora.
Sterile
• all internal tissues & organs • all fluids with organs or tissue
Sterile areas of the body
• Initial response of host defenses comes from phagocytes • Antiphagocytic factors - used to avoid phagocytosis - poison to leukocytes o Species of Staphylococcus and Streptococcus produce leukocidins, toxic to white blood cells o Slime layer or capsule - makes phagocytosis difficult - this slime layer SLOWS PHAGOCYTOSIS o Ability to survive intracellular phagocytosis
Surviving Host Defenses
pathogen spreads to many sites or systems
Systemic infection
a. incubation period - time from initial contact with the infectious agent and the appearance of first symptoms (2-30 days); agent is multiplying but damage is insufficient to cause symptoms; several hours to several years b. prodromal stage earliest symptoms (generalized symptoms) of infection; include: head ache, fatigue, nausea, fever, muscle aches (1-2 days) -- generic type Sx appear. Still cant tell what infection is. c. period of invasion - microbe multiplies at highest rate, exhibits greatest toxicity and is well established in target tissue; marked by classic symptoms of particular disease characteristics -- Sx of disease. Can tell more which type of disease it is. d. convalescent period - patient's immune system begins to overcome the microbe, symptoms begin to fade, patent's strength returns and the body system comes back to normal - immune system begins to kill microbe, pt starts feeling better, recovery begins.
THE 4 STAGES A PATIENT WILL GO THROUGH Classic Stages of Clinical Disease
Flora of the Skin Name the 2 cutaneous populations
TRANSIENTS & RESIDENTS
a. Animal reservoirs - diseases that naturally occur in animals and are spread to humans are called zoonoses (EX: RABIES) b. Human reservoirs - those with active diseases and asymptomatic (carriers) - will only live in humans, only found in humans, only grows in humans c. Nonliving reservoirs - soil, water, food (live in food, water & soil - ex: e. coli)
Types of reservoirs
sexual, displaced organisms
Urogenital tract
1. Mechanical Vector - does not infect bug, carried on bodies of bug = flies & roaches 2. Biological Vector - infects the bug, bug bites human = fleas, mosquiots & ticks
Vector Transmission
substances that can harbor a microbe for a short time, not long / microbe doesn't like to stay here permanantly 1. Airborne - dust particles 2. Waterborne - streams, standing water, swimming pools, water supply 3. Foodborne - meats, prepared foods
Vehicle Transmission
traits used to invade and establish themselves in the host, also determine the degree of tissue damage that occurs - severity of disease
Virulence factors
• The human body exists in a state of dynamic equilibrium • Many interactions between human body and microorganisms involve the development of biofilms • Colonization of the body involves a constant "give and take"
We Are Not Alone
disease exhibits a relatively steady frequency over a long time period in a particular geographic locale.
endemic occurrence
Composed of lipopolysaccharide (LPS), part of the outer membrane of gram-negative cell walls • only released when microbe is damaged and is falling apart • causes systemic effects (Sx)= fever, diarrhea, hemorrhaging, blood coagulation, septic shock
endotoxin
a disease is increasing beyond what is expected for that population.
epidemic
enzymes that chemically break down or dissolve host's barriers and promote the spread of microbes to deeper
exoenzymes
protein secreted that goes to site of action = target tissue - produced by gram positive and gram negative - very powerful and deadly can be classified by target tissue: • hemotoxins - lyse blood cells • enterotoxins - affect intestinal mucosa • neurotoxins - affect nerve tissue • cytotoxins - affect general tissue
exotoxin
protein secreted that goes to site of action = target tissue - produced by gram positive and gram negative - very powerful and deadly
exotoxin
Name the Sx of an ENDOTOXIN
fever, diarrhea, hemorrhaging, blood coagulation, septic shock
What is the PATHOGEN'S goal in life ?
find a good place to live and multiply / REPRODUCE
digests hyaluronic acid (like cell give)
hyaluronidase - (exoenzyme)
time from initial contact with the infectious agent and the appearance of first symptoms (2-30 days); agent is multiplying but damage is insufficient to cause symptoms; several hours to several years
incubation period
second infection
secondary infection
disease is occurs as occasional cases at irregular intervals in unpredictable locales. (ex: tetanus, rabies)
sporadic