Pathogens, Diseases, and Virulence Factors

Virulence Factor: SipA/SopE

Pathogen: Salmonella enterica

Mechanism of Action: Injected via T3SS that force host cells to phagocytose bacterial cell

V.Factor: Pili/fimbriae

Pathogen: Many including E. coli and Neisseria gonorrhoeae

M.O.A: Attach to host cells. In the case of Neisseria, undergo antigenic variation to help hide from adaptive immune system.

V.Factor: Capsule

Pathogen: Many including Streptococcus pneumoniae

M.O.A: Prevents phagocytosis by blocking antibody/complement recognition

V.Factor: Fibronectin binding proteins (FnBP A/B)

Pathogen:: Staphylococcus aureus

M.O.A: Bind to fibronectin & aid in attachment to host tissue

V. Factor: Tir/Intimin

Pathogen: Escherichia coli (EPEC and EHEC)

M.O.A: Bacterial proteins that act as a host receptor (Tir) and ligand (intimin) and induce actin remodeling which forces the host cell to form a pedestal that the bacteria attach to

V.Factor: InlA/InlB

Pathogen: Listeria monocytogenes

M.O.A: Induces phagocytosis via a zipper mechanism

V.Factor: DNase

Pathogen: Streptococcus pyogenes

M.O.A: Degrades neutrophil NETs

V.Factor: Protein A

Pathogen: Staphylococcus aureus

M.O.A: Binds antibodies by Fc regions and prevents opsonizations

V.Factor: IgA protease

Pathogen: Neisseria gonorrhoeae

M.O.A: Protease that degrades IgA

V.Factor: ActA

Pathogen: Listeria monocytogenes

M.O.A: Generates actin tail that push bacteria through cytoplasm

V.Factor: Diptheria toxin

Pathogen: Corynebacterium diptheriae

M.O.A: AB toxin that inhibits protein synthesis by ribosylating EF2.

V.Factor: Shiga toxin

Pathogen: Shigella dysenteriae and some strains of E. coli (EHEC)

M.O.A: AB toxin that inhibits protein synthesis by degrading rRNA

V.Factor: Pertussis toxin

Pathogen: Bordetella pertussis

M.O.A: AB toxin that increases cAMP levels by that interferes with G-protein coupled signaling by ribosylating a G_i - protein

V.Factor: Cholera toxin

Pathogen: Vibrio cholerae

M.O.A: AB toxin that increases cAMP levels by that interferes with G-protein coupled signaling by ribosylating a Gsprotein

V.Factor: Botulinum toxin

Patogen: Clostridium botulinum

M.O.A: AB toxin that acts as a protease and blocks release of acetylcholine through cleavage of SNAP-25.

V.Factor: Tetanus toxin

Pathogen: Clostridium tetani

M.O.A: AB toxin that acts as a protease and blocks release of GABA through cleavage of synaptobrevin

V.Factor: LLO

Pathogen: Listeria monocytogenes

M.O.A: Cytolytic toxin that disrupts the phagosomal membrane before fusion with the lysosome

V.Factor: Alpha toxin

Pathogen: Staphylococcus aureus

M.O.A: Cytolytic toxin that destroys the host cell membrane

V.Factor: PV leukocidin

Pathogen: Staphylococcus aureus

M.O.A: Cytolytic toxin that disrupts the cell and mitochondrial membranes

V.factor: Superantigens

Pathogen: Staphylococcus aureus and Streptococcus pyogenes

M.O.A: Non-specific T-cell activation that causes massive cytokine release.

Cavities/Gingivitis causative agent?

Polymicrobial community including:

Fusobacterium,

Strepotococcus mutans,

Porphyromonas gingitivis

Cavities/Gingivitis Microbe Type?

Mixed bacterial community

Cavities/Gingivitis Major Method of Spread?

Uncontrolled growth or imbalanced microbial community causes problems

Cavities/Gingivitis Organ sys. affected?

Mouth

Cavities/Gingivitis Major Virulence Mechanisms?

Production of lactic acid causes demineralization of the tooth.

Plaque buildup can cause inflammation of the gums.

SSTI, necrotizing fasciitis, food poisoning, TSS, scalded skin syndrome, food poisoning, osteomyelitis, endocarditis, meningitis, pneumonia, sepsis - C.A?

Staphylococcus aureus/MRSA

SSTI, necrotizing fasciitis, food poisoning, TSS, scalded skin syndrome, food poisoning, osteomyelitis, endocarditis, meningitis, pneumonia, sepsis - M.T?

Gram - positive bacterium

SSTI, necrotizing fasciitis, food poisoning, TSS, scalded skin syndrome, food poisoning, osteomyelitis, endocarditis, meningitis, pneumonia, sepsis - M.O.S?

Direct/indirect contact

SSTI, necrotizing fasciitis, food poisoning, TSS, scalded skin syndrome, food poisoning, osteomyelitis, endocarditis, meningitis, pneumonia, sepsis - Common Sys./ organs affected?

Depends on nature of infection.

Most common are ____ infections such as boils.

SSTI, necrotizing fasciitis, food poisoning, TSS, scalded skin syndrome, food poisoning, osteomyelitis, endocarditis, meningitis, pneumonia, sepsis - Major V.mechanisms?

Alpha toxin,

PVCleukocidin,

Protein A,

Fibronectin binding proteins,

Capsule,

Toxic shock syndrome toxin,

Exfoliative toxin,

Staphylococcal enterotoxin

Lyme disease - C.A?

Borrelia burgdorferi

Lyme disease - M.T

Bacteria;

Spirochete;

Gram-negative

Lyme disease - M.O.S?

Vector - deer tick

Lyme disease - Common Symp/Organs?

Preferentially grows in skin, nerve tissue, synovium (joint lining), and conduction system of heart and can cause myalgia, arthritis or neurological defects if left untreated

Virulence: N/A

Vaginal yeast infections; thrush - C.A?

Candida albicans

Vaginal yeast infections; thrush - M.T?

Fungus (yeast)

Vaginal yeast infections; thrush - M.O.S?

Opportunistic pathogen that is part of the normal flora. May become too prevalent after course of antibiotics

Vaginal yeast infections; thrush - Common Symp./Organ?

Vagina,

mouth - redness or burning sensation

Virulence: N/A

Gastric ulcers - C.A?

Helicobacter pylori

Gastric ulcers - M.T?

Bacterium

Gastric ulcers - M.O.S?

Contact with saliva, vomit, feces; contaminated food or water

Gastric ulcers - Common symp/Organs?

Discomfort when you eat,

Nausea,

Vomiting blood;

Formation of stomach ulcers

Gastric ulcers - Major V. mechanismS?

Urease (neutralizes stomach acid)

Botulism - C.A?

Clostridium botulinum

Botulism - M.T?

Bacterium;

Obligate anaerobe;

Gram-positive

Botulism - M.O.S?

Usually spread via spores.

Food-borne most common; wound or ingestion

Botulism - Common symp./Organs?

Nervous system (flaccid paralysis)

Botulism - Major V.Mechanisms?

Botulinum toxin - AB toxin that acts as a protease and prevents acetycholine release

Pseudomembranous colitis - C.A?

Clostridium difficile

Pseudomembranous colitis - M.T?

Gram-positive;

Obligate anaerobe,

Sporeforming bacteriuam

Pseudomembranous colitis - M.O.S?

Often arises after antibiotic treatment that destroys normal flora

Pseudomembranous colitis - Common symp./Organs?

Severe diarrhea;

Weight loss.

Recurrent infections are a major issues

Pseudomembranous colitis - Major V.Mechanisms?

Secreted toxins cause inflammation/tissue damage in intestine

Tetanus - C.A?

Clostridium tetani

Tetanus - M.T?

Bacterium;

Obligate anaerobe;

Gram-positive

Tetanus - M.O.S?

Wound infection;

spread via spores

Tetanus - Common symp./Organs?

Nervous system (spastic paralysis)

Tetanus - Major V.mechanisms?

Tetanus toxin—AB toxin that acts as a protease and prevents GABA release

Diphtheria - C.A?

Corynebacterium diphtheriae

Diphtheria - M.T?

Gram-positive

Diphtheria - Common symp./Organ?

Bull neck;

pseudomembrane that blocks airway

Diphtheria - Major V.mechanisms?

Diphtheria toxin

Cholera - C.A?

Vibrio cholerae

Cholera - M.T?

Gram-negative bacterium

Cholera - M.O.S?

Fecal-oral

Cholera - Common symp./Organ?

Massive amounts of watery diarrhea

Cholera - Major V.Mechs?

Cholera toxin—increases cAMP levels via ADP ribosylation;

capsule

Dysentery; Hemolytic uremic syndrome - C.A?

EHEC

Dysentery; Hemolytic uremic syndrome - M.T?

E. coli strain (gram-negative)

Dysentery; Hemolytic uremic syndrome - M.O.S?

Fecal-oral;

Food borne

Dysentery; Hemolytic uremic syndrome - common symp./organs?

Diarrhea (sometimes bloody),

Abdominal cramps,

Nausea, little to no fever

In cases of HUS, Can lead to destruction of RBCs renal failure, stroke, or coma

Dysentery; Hemolytic uremic syndrome - Major V.Mech?

Shiga toxin,

Tir (T3SS) &

intimin,

capsule (most strains)

Diarrhea (EPEC) - C.A?

EPEC

Diarrhea (EPEC) - M.T?

E. coli strain (gram-negative)

Diarrhea (EPEC) - M.O.S?

Fecal-oral

Diarrhea (EPEC) - Symp./Organ?

Usually watery diarrhea

Diarrhea (EPEC) - Major V.Mechs?

Tir (secreted via T3SS) and intimin;

Capsule (most strains)

Diarrhea 2 - C.A?

ETEC

Diarrhea (ETEC) - M.T?

E. coli strain (gram-negative)

Diarrhea (ETEC) - M.O.S?

Fecal-oral

Diarrhea (ETEC) - Symp./Organ?

Watery diarrhea;

Typically no fever

Diarrhea (ETEC) - Major V.Mechs?

Capsule (most strains);

LT toxin increases cAMP levels via ADP-ribosylation.

Diarrhea 3 - C.A?

Norovirus

Diarrhea (Norovirus) - M.T?

Virus

Diarrhea (Norovirus) - M.O.S?

Fecal-oral

Diarrhea (Norovirus) - Symp./Organ"?

Diarrhea, vomiting

Virulence: N/A

Diarrhea 4 - C.A?

Rotavirus

Diarrhea (Rotavirus) - M.T?

Virus

Diarrhea (Rotavirus) - M.O.S?

Fecal-oral

Diarrhea (Rotavirus) - Symp./Organ?

Vomiting, fever, severe diarrhea possible

Virulence: N/A

Listeriosis - C.A?

Listeria monocytogenes

Listeriosis - M.T?

Gram-positive bacterium

Listeriosis - M.O.A?

Food-borne

Listeriosis - Symp./Organs?

Gastroenteritis

In severe cases, meningitis, pneumonia or miscarriage

Listeriosis - V.Mech?

LLO,

ActA,

Adhesins (InlA/InlB)

C.A - Streptococcus pyogenes (aka GAS)

Many Diseases

Streptococcus pyogenes (aka GAS) - M.T?

Gram-positive bacterium

Streptococcus pyogenes (aka GAS) - M.O.S?

Direct /indirect contact, respiratory droplets

Streptococcus pyogenes (aka GAS) - Symp./Organs?

Depends on nature of infection but SSTIs are the most common.

Streptococcus pyogenes (aka GAS) - V.Mechs?

Fimbriae/pili,

M-protein,

Capsule,

DNase,

Superantigen,

C5a peptidase