Chapter 21 Cardiovascular/Systemic Bacterial Diseases

What are the stages in which a disease can progress through?

Local -> Systemic -> Focal

What is Septicemia?

Any type of microbial infection of the blood, causing the bacteria to multiply (nutritious environment)

What is Bactermia?

Presence of bacteria in the blood, but it's not replicating

What is Toxemia?

Release of bacterial toxins into blood, where toxins produced are in the blood

What is Lymphangitis?

Painful infection and inflammation of the lymphatic vessels

What is Viremia?

Virus in the blood

What are the signs and symptoms of Septicemia, Bacteremia, and Toxemia?

- Fever, nausea, diarrhea, malaise

- Possible rapid developing septic shock

- Petechiae can develop

- Osteomyelitis may develop (if bacteria invades bones)

- Toxemia: exotoxins vs endotoxins

What is malaise?

a vague sense of body discomfort, weakness and fatigue

What is petechiae?

Small dot like pinpoint hemorrhages on the skin.

What is Osteomyelitis?

a severe infection of bone, bone marrow, and surrounding soft tissue.

What separates Toxemia?

-Exotoxin: Gram POS+ bct., proteins, super toxic

-Endotoxin: Gram NEG- bct., Lipid A part of LPS, less toxic

What is the Pathogenesis and Epidemiology of Septicemia, Bacteremia, and Toxemia?

- Healthy people rarely have septicemia, with limited bct. infections

- Septicemia is a direct inoculation of bacteria into the blood (Gram NEG- bct. produces the most severe form of this)

How does Gram NEG- bacteria produce the most severe septicemia?

- Release of endotoxin as the bacteria dies

- This can lead into systemic inflammation (shock drop in BP, coagulation, and fever)

What are the Pathogens/Virulence Factors of Septicemia, Bacteremia, and Toxemia?

They can be caused by various bacteria

- Opportunistic of Healthcare associated infections (Pseudomonas, Neisseria, E. coli, Salmonella)

- Caused by Gram-Negative Bacteria (Endo Toxin)

- Sometimes Gram Positive (S. aureus, S. pneumonia, S. pyogenes)

What are some of the Gram Positive Bacteria that can cause Septicemia/Toxemia?

S. aureus, S. pneumonia, S. pyogenes

What are affects of Endotoxins?

-Initiates Inflammatory Reactions

-Disseminated intravascular coagulations

-Activates compliment

-Disseminated intravascular coagulation and complement

How do endotoxins initiate inflammatory reactions?

Lipid A causes Leukocytes to release cytokines: TNF-alpha, IL-1, and IL-6

ALL PROINFLAMMATORY CYTOKINES

How do endotoxins disseminate intravascular coagulation?

Lipid A's PAF (platelet activating factor) causes blood-clots to occur and causing DIC (coagulation basically)

How do endotoxins trigger inflammation?

Activating the complement with C3a and C5a, it causes inflammation

What causes endotoxic shock?

Plasma loss, reduction of BP, and inflammation from the DIC + complement and such all from Lipid A

What does TNF and IL-1 lead to from Lipid A?

Fever

What does IL-1 do from Lipid A?

Immature neutrophils are released, damaging blood vessel walls, and leading to plasma loss, reduction of BP

What does IL-6 and IL-8 do from Lipid A

Damage blood vessel walls

Leading to plasma loss, reduction of BP

What does IL-8 do specifically?

Attracts more neutrophils to the area and increases inflammation

What are the signs and symptoms of Endocarditis?

Inflammation of the endocardium, fever, fatigue, malaise (general pain), and difficulty breathing

May detect Tachycardia (faster heartrate)

What are the pathogens of Endocarditis?

-Normal microbiota are usually responsible

-Viridans streptococci cause about half the cases

What is viridans streptococci?

- Heterogeneous group of strep bacteria

- Part of normal flora

- Present mostly in oral cavity

- Usually only in people with bad oral health

How can viridans streptococci affect other parts of the body?

Mostly in the mouth/oral cavity, it can multiply and go into your blood stream and into your heart valves

What are the pathogenesis and epidemiology of Endocarditis?

Patients with abnormal heart have an increased risk

How do Bacterial Cardiovascular and Systemic Diseases move about?

Systemic diseases are carried throughout the body, through blood/lymph

How do Bacterial Cardiovascular and Systemic Diseases come to be?

An initial or focal infection involved such as

-Infected Tooth

-Skin lesion

-Intravascular Catheter

Local to Systemic to Focal

Which group of people do Bacterial Cardiovascular and Systemic Diseases affect the most?

This type of disease is common among drug users

What are the signs and symptoms of Brucellosis?

Undulant Fever, spiking every afternoon but not the evening

What is an undulant fever?

A fluctuating fever that rises and falls at abnormal times

What are the pathogen/virulence factors of Brucellosis?

-Caused by Brucella melitensis, gram- and endotoxins

- Zoonotic

- Intracellular (phagocytes)

How are people infected by Brucellosis?

It is a zoonotic disease that infects people through milk and no vectors at all

What are some characteristics of Brucella melitensis?

Gram NEG-, has endotoxins, intracellular (phagocytes), survives phagocytes, has toxins

What is the pathogenesis and epidemiology of Brucellosis?

Caused by consumption of contaminated dairy products (milk)

-Contact with animal blood, urine, or placentas

-Passed on by unpasteurized milk

What can decontaminate dairy products from Brucellosis?

Contaminated dairy products can be fixed from pasteurization

What does Pasteurization do?

Aims to remove or kill only the bacteria that causes disease (not sterilizing)

What are the signs and symptoms of Tularemia?

AKA rabbit fever

-Skin lesions and swollen lymph nodes at the site of infection

-Ascending lymphangitis (lymph vessels swollen)

What are the pathogen and virulence factors of Tularemia?

Caused by Francisella tularensis, which is

-Very small

-Low multiplicity of infection

-Zoonotic

-Can survive through a lot

-Endotoxin can cause many signs and symptoms

Why is Francisella tularensis so dangerous?

Considered a gov. bioterrorism weapon

1) Doesn't need a portal of entry since it squeezes through skin cells

2) Only needs 2 cells to kill you due to low multiplicity of inection

3) Prevents phagosome and lysosome fusion, allowing it to survive a lot

What is the pathogenesis and epidemiology of Francisella tularensis?

-Transmitted via bite of infected tick or contact with infected animal (tick or rabbits/dogs)

-Small size can allow entry through seemingly unbroken skin

- Individuals around dead animals high risk

What are the signs and symptoms of the Bubonic Plague?

-Characterized by buboes (enlarged lymph nodes)

-Can become systemic (pneumonic plague)

What are Buboes?

Swollen, enlarged, and infected lymph nodes

What does the Bubonic plague affect?

It can affect sentinal lymph nodes such as the

-Axillary

-Groin

Grows to the size of a golf/tennis ball due to main source of drainage

What is Pneumonic plague?

When the bacterium spreads to the lungs, where difficulty breathing can develop fast

100% death rate

What is the pathogen of the Plague?

Caused by Yersinia pestis, from rat fleas

-Considered zoonotic since it is transmitted by rat flea

What is the natural history and transmission of Yersinia pestis?

1) Natural endemic reservoir hosts (rodents)

2) Amplified by most mammals as hosts

3) Direct contact through bite causes buboes (flea/rodent to human)

4) Airborne transmission (human to human) leads to pneumonic plague

What is the pathogenesis and epidemiology of the plague?

Zoonotic disease, transmitted from infected animal/flea feces

-Bubonic fatality is 50% if untreated

-Pneumonic fatality is 100% if untreated

AKA black death

What is Ring Around The Rosie about?

Basically the plague and the aftermath,

-flea bites you

-decay smell masked by flowers

-burned victims

-death

What is the meaning behind God Bless You?

Sneezing was rare, so people thought you had the plague, so they blessed you before you died

What are the signs and symptoms of Lyme Disease?

Bull's-eye rash at infected site

-If not treated: Neurological symptoms (Encephalitis, cardiac dysfunction)

-Severe arthritis from immune response

What are the pathogen and virulence factors of Lyme Disease?

-Caused by Borrelia burgdorferi (spirochete)

-Spread by Ixodes tick, zoonotic

-Avoids immune detection by altering membrane proteins

How does Borrelia burgdorferi attain antibody resistance?

Has the ability to modify membrane proteins, whenever the body makes antibodies for the antigen/protein, causing it to be resistant

What is the treatment for Lyme Disease?

Doxycycline for 14-21 days

Is there a thing for chronic lyme disease?

No, if it was chronic, you'd need to be able to isolate the bacteria

What is the Epidemiology for Lyme Disease?

Three events helped to increase Lyme disease

-People moving into woodland areas

-Deer population being protected

-Displaced foxes that would control mouse population from coyotes

What are the signs and symptoms of Ehrlichiosis and Anaplasmosis?

-Resembles the flu

-Leukopenia and thrombocytopenia occurs

What are the pathogen and virulence factors for Ehrlichiosis and Anaplasmosis?

-Ehrlichia chaffeensis causes ehrlichiosis

-Anaplasma phagocytophilum causes anaplasmosis

Both bacteria live inside phagosomes

What is the Pathogenesis of Ehrlichiosis and Anaplasmosis?

Ticks transmit the bacteria to humans

What are signs and symptoms of Infectious Mononucleosis?

Pharyngitis (severe sore throat), fever occurs at start then,

Followed by swollen lymph nodes (neck/axillary), extreme fatigue (~24 HR Sleep), Appetite loss

What are the pathogen and virulence factors of Infectious Mononucleosis?

Caused by Epstein-Barr virus or Human Herpes Virus-4 (EBV or HHV-4)

-EBV establishes latent infection

AKA kissing's disease

What is special about HHV-4 aka EBV?

This Herpes virus hides in the nervous system, and goes latent within B-cells

Could cause Burkitts lymphoma

What can EBV do to establish latent infection in the host?

It can suppress the apoptosis of infected B cells, which can cause Burkitt's lymphoma

Where do the symptoms of Infectious Mononucleosis come from?

Happens from T-cells killing B-cells, not an autoimmune disease since B cells seem foreign (altered self)

What happens when you have an immature immune system with EBV?

You'll be Asymptomatic

What happens when you have an Lacking immune system with EBV?

Can cause Leukoplakia, or oral hairy leukoplakia

This forms a huge cilia in the side of the tongue

What happens when you have an Poor immune system with EBV?

Could cause

-Burkitt's Lymphoma

-Nasopharyngeal cancer

-Chronic Fatigue Syndrome

-Hodgkin's Lymphoma

What happens when you have an Vigorous immune system with EBV?

Infectious mononucleosis, but

Adults are more vigorous so they have a worse response to chickenpox than kids

What are the signs and symptoms of Cytomegalovirus Disease?

Usually Asymptomatic, but

-Complications in neonates/fetuses, and immunocompromised could occur (enlarged liver, spleen, jaundice)

What does hepatomegaly cause?

It is an enlarged liver, which can cause jaundice

What is Splenomegaly?

It is an enlarged Spleen

What is the Pathogenesis and Epidemiology of Cytomegalovirus Disease?

Transmitted with direct contact with bodily fluids/transplacentally

One of the most common infections for people

What are the signs and symptoms of Dengue Fever?

1st Phase) High Fever, edema, head, and muscle pain (break-bone fever)

2nd Phase) Return of Fever and Red Rash

What is Break Bone Fever?

A high fever with intense muscle pain so intense, they feel like their bones are going to break

What are the signs and symptoms of Dengue hemorrhagic fever?

Internal bleeding, shock, and possibly death,

this happens when you get a reinfection

What are the pathogens and virulence factors of Dengue/Dengue Hemorrhagic Fever?

There are four strains of dengue viruses

-Aedes mosquitos are the vector

-Tropical virus

How does Dengue Hemorrhagic Fever come to be?

Antibodies to dengue virus in blood cause a complex to occur, which are phagocytized by APC

This causes memory T-cells to be activated, increased production of inflammatory lymphokines occurring too (BASICALLY TYPE III HYPERSENSITIVITY, AND CYTOKINE STORM)

Leading to hemorrhagic death (10-50%)

What are the signs and symptoms of African Viral Hemorrhagic Fever?

Fever, Fatigue, and minor petechiae (lesions from an issue with blood clotting cascade)

As well as severe internal Hemorrhaging

What are the pathogens and virulence factors of African Viral Hemorrhagic Fever?

Caused by Ebolavirus or Marburgvirus (both are Filoviridae)

What are Filoviridae?

ssRNA- virus family that host the Ebola/Marburg

What is pathogenesis and epidemiology of African Viral Hemorrhagic Fever?

Malfunctioning blood clotting causes hemorrhaging

What is the Diagnosis, Treatment, and Prevention of African Viral Hemorrhagic Fever?

-Diagnosis based on symptoms/presence of virus in blood (antibody based looking at virus)

-Treatment involves passive immunotherapy of fluid/electrolyte replacement (able to donate serum to others)

-FDA approved vaccine in Dec 2019

What are the signs and symptoms of Malaria?

Associated parasite's lifecycle in erythrocytes

- Fever, chills, diarrhea, headache, weakness

- Flu-like symptoms

What is the pathogen and pathogenesis of Malaria?

-Caused by ~4 Plasmodium species, which affects the severity

-Schizogony occurring in fever, can cause jaundice and merozoites in blood etc.

What happens when Schizogony occurs in the liver of Malaria hosts?

-Jaundice

-Merozoites in blood formed from multiple mitoses/delayed cytokinesis

-Signet rings are the diagnosis of malaria from blood

What can help protect you from Malaria?

Sickle cell anemia can make you resistant/protected against the disease

Part of the apicomplexa (idk if applicable)

What causes the most severe form of malaria?

P. falciparum

What is the plasmodium life cycle (steps)?

1) Anopheles mosquito injects sporozoites in blood and into live

2) 2 Weeks later, 30-40k merozoites are released and damages liver

3) Erythrocytes/RBCs are penetrated by free merozoites

4) Merozoites morph into trophozoites through a ring form

5) Trophozoites produce merozoites from schizogony, leading to merozoites bursting and leading hemoglobin releasing

6) Merozoites can mature into male/female gametocytes within erythrocytes

What are the Virulence Factors for Malaria?

The reproductive cycle hides parasites from immune surveillance

-RBCs can adhere to some tissues from Adhesions, preventing spleen clearance

-Changes in breath/body odor attract more mosquitos

What are the signs and symptoms of Toxoplasmosis?

-Majority are asymptomatic

-Symptoms arise in poor immunity individuals

-Fetal infections can cause conditions (spontaneous abortion/stillbirth)

What are some of the symptoms in individuals with poor immunity for Toxoplasmosis?

Fever, malaise, and inflammation of lungs, liver, and heart

What are the pathogen and virulence factors for Toxoplasmosis?

Caused by Toxoplasma gondii

-Part of apicomplexa

-Vulnerable population: pregnant women and immunocompromised patients

What's the host for Toxoplasma gondii?

Cats are the definitive host, where Cysts are found in the fecal matter of the cat

What happens when Toxoplasma gondii is inside a pregnant woman?

If it is able to cross the placenta barrier, it can lead to spontaneous miscarriage

How can the vulnerable population of Toxoplasma gondii lower their risl?

Avoid the litterbox, as well as avoiding undercooked meat

What is the life cycle of Toxoplasma gondii?

1) Toxoplasma gondii (parasite) replicates sexually in the digestive system of cat, and immature oocysts are shed in cat feces

2) Oocysts produce internal sporozoites

3) oocysts ingested by rodent, or human being

4b) Sporozoites invade tissue, making bradyzoites and forming pseudocysts

5B) Pseudocysts are ingested by human in undercooked meat

What happens after a rodent ingests the oocysts from Toxoplasma gondii?

4a) Sporozoites invade the tissue, developing into bradyzoites within cells. The masses of bradyzoites become pseudocysts

5a) Pseudocysts are ingested by cat in wild prey or undercooked meat (basically cat eats the rodent)