lacture 15

Phenolics affect—- and/or —

•NOT —

protein function , disrupt membranes, sporicidal

Alcohols Colorless hydrocarbons with— groups

–OH

— alcohol are they only two used for microbial control

Ethyl and isopropyl

alcohol Concentrations >50% destroy —

cell membranes

Aldehydes are Organic substances with a — on the terminal carbon

–CHO

2 examples of Aldehydes

gluaraldehyde and ortho-phthaldehyde (more potent)

Aldehydes Mode of action

Causes cross-linking of proteins on the cell surface

• Disrupts proteins activity

when do Aldehydes become sporicidal

Sporicidal after three hours of exposure

Aldehydes Becomes unstable in —

increased pH and temperature

Chlorine dioxide gas: disrupts —

proteins

Chlorine dioxide gas Used to treat —

(large scale)

drinking water, wastewater, medical waste, and buildings

Ethylene oxide gas Reacts with —

DNA and proteins

Ethylene oxide gas 2 bad traits

Explosive

• Carcinogen

Detergents function

solubilize membranes and disrupt proteins

2 examples of detergents

Cationic Detergents and Nonionic detergents

Cationic Detergents —charged

Positively

Cationic Detergents More effective Against —

G+, viruses, fungi, algae

ex of Nonionic detergents

Soaps

— grows IN soap dishes!!!

Pseudomonas

what are modern heavy metals used in chemical control

mercury and silver

Oligodynamic what does this ability from heavy metals mean

exters antimicrobial effects in very small amounts

downsides of using Heavy Metals

Extremely toxic, easy to develop resistance, cause allergic reactions

Heavy Metals mode of action

Bind to and inactivate proteins

Ebola discovered when and where

Discovered in 1976 in Democratic Republic of Congo

ebola mode of infection and from what

Believed to be animal-borne, Bats

Ebola Affects

Affects humans and non-

human primates

Transmission of Ebola Initially via a —

spillover event: direct contact with an infected animal

a person can contract ebola by what fluids

blood or bodily fluids

You must be —to transmit the ebola virus

symptomatic

Incubation period of ebola

2-21 days (7-11 days)

ebola survives how long on surfaces and bodily fluids

Survives for hours on dry surfaces, Survives for days in bodily fluids

Ebola Virus Disease Symptoms

Fever

• Severe headache

• Muscle pain

• Weakness

• Fatigue

• Diarrhea

• Vomiting

• Stomach Pain

• Hemorrhage

Treatment of ebola

Supportive care

• Fluids and electrolytes

• Oxygen

• Manage other symptoms

what Antiviral Drugs cant treat ebola

NONA

— mortality rate of ebola

25%-90%

— can cause infection and disease in a healthy host.

• Sometimes called a true pathogen

Primary pathogen:

— _: only causes infection and disease in non-healthy individuals OR when

introduced in a normally sterile part of the body

Opportunistic pathogen

_______________: degree of pathogenicity of a parasitic microbe

Virulence

_______________: properties of a pathogen that allow it to successfully invade and cause disease in a host

Virulence factors

3 Phases of an Infection

Entering the host

• Attaching to the host

• Invading and becoming established

How to start an infection: Getting in

Portal of entry: —-

The tissue by which an organism enters a hosts body

Exogenous infection:

Originates from an outside source

Endogenous infection:

Originates from the normal flora of the host

Common portals of entry:

Skin and mucous membranes

• GI Tract

• Respiratory System

• Urogenital Tract

• Pregnancy and Birth

what are the ways pathogens get past the Skin and Mucous Membranes:

Damaged skin

• Mucosal membranes

Alternative ways pathogens get past the Skin and Mucous Membranes

Enzymes that break skin barrier

• Bites

• Artificial damage

• Conjunctiva

a pathogen must be ingested to enter the —-

GI Tract

Pathogens must have a mechanism to survive — of the stomach

digestive enzymes and acidic

pH

pathogens Usually colonize —

small or large intestine

what is the Portal for the largest number of pathogens

Respiratory

Respiratory Invaders include —

bacteria, viruses, and fungi

Genitourinary Tract is Portal of entry for

STIs (sexually transmitted infections)

how many bacteria and viruses are responsible for STIs

Eight

examples of infections caused by displaced organisms

Yeast infections

• UTIs

The placenta acts as a barrier to protect against —

transmission of

infection from mother to developing fetus

what are 3 exceptional pathogens that can still reach the fetus

Listeria monocytogenes

• TORCH Infections

• Vaginal tract during birth

Infectious Dose: defintiion

minimum number of

infectious microbes that must be present to

cause an infection

High ID: must travel —

farther in the body before establishing infection

Lower ID: infect —

locally

Adhesion: —

firm attachment to the host tissue

Bacteria, Fungi, and Protozoa use what to attach

Flagella, pili, slimes, capsules

Viruses attach to

Receptors

Parasitic Worms use what to attach

Suckers, hooks, barbs

Adhesin: definition

protein or glycoprotein on a cell’s surface that attaches

to a host cell via receptors

Adhesin is produced by

Produced by prokaryotic, eukaryotic, and viral pathogens

Protein F Fibronectin-binding protein produced by —

Streptococcus pyogenes

Protein F Aids in binding to

respiratory epithelial cells

N-methylphenylalanine pili Extracellular appendage of

Vibrio cholerae

N-methylphenylalanine pili Aids in

attachment to intestinal epithelial cells

80% of UTIs are caused by

E. coli

E. coli cells produce specialized pili (Type 1 pili) that have

special adhesion proteins

long paragraph: ecoli has type 1 pilli that acts as an arm from teh bacteria to the host cell. The fim operon is a cluster of genes that work together. the fin operon contains all the instructions the e.coli needs to build the entire pilus structure. FimH protein is the actual special adhesin. This protein GRABS onto the sugar recptors on your bladder . Hooks is used as a medaphor for how the fimH protein functions.

Antibiotic Resistant UTIs Commonly treated by

Ciprofloxacin or Bactrim

Ciprofloxacin: Fluoroquinolone that inhibits

—

gyrases

Bactrim: Trimethoprim/Sulfamethoxazole

combo that inhibits

folate synthesis

Infection is just being there. — is how good the germ is at being "bad."

Virulence

2 categories of Virulence Factors

Antiphagocytic Factors, Exoenzymes

Antiphagocytic Factors these are designed to stop

Phagocytes

what are two of the most effective Antiphagocytic Factors

Leukocidins and Capsules

Leukocidins: These are chemicals produced by bacteria (like Staph) that literally—

kill white blood cells

Capsules: As we mentioned in attachment, these are slippery, sugary shells. In this phase, they act like a —

"cloaking device."

Exoenzymes : These are —

proteins secreted by the pathogen to break down host tissues

Toxin: defintion

chemical product of microbes, plants, or animals that has a

poisonous affect on other organisms

Toxinose: definition

diseases caused by bacteria that produce toxins

Toxemia: defintion

spread of toxins by the blood from infection site (i.e.,

tetanus)

• Intoxication: defintiion

ingestion of toxins (i.e., botulism)

Exotoxins

• Toxin secreted by -

a living bacterium into a

tissue

Exotoxins Only need a — to be toxic

little bit

exotoxin is Cell-type specific what does tha tmen

the toxin goes after only a specific cell type to attack

exotoxins are —

proteins

Exotoxins are — at high temperatures

Unstable

Exotoxins are produced by — bacteria

Gram-positive (G+) and Gram-negative (G-)

Endotoxins toxin that is —

released after the cell is

damaged or lysed

Endotoxins — amounts needed for toxicity

Larger

Endotoxins cause a —- to go under

system

LPS = Lipopolysaccharide. Endotoxin is the — molecule found in the outer cell wall of —

LPS (Lipopolysaccharide), Gram-negative bacteria

Endotoxins — at high temperatures

Stable

endotoxins are made of only — bacteria

g-

Stages of Infection - Stage 1: Incubation Period what happens here and for how long

• Initial contact with the pathogen to the first

symptom

• Pathogen multiplies at portal of entry

• Length of this phase depends on pathogen

• Hours - Years

Stages of Infection Stage 2: Prodromal Stage what happens here and for how long

• When initial symptoms are felt

• Very short period

• 1-2 days

• Severity of symptoms is not high