Microbio diesease

Pyoderma

infections of the skin that produce pus

Staphylococcus aureus infections

Can infect hair follicles and cause folliculitis which appears as pimples

Sty

Infection of an eyelash follicle caused by Staphylococcus aureus

Furuncle (boil)

A deeper infection of a hair follicle caused by Staphylococcus aureus

Carbuncle

Multiple connected boils forming a larger infected area

Leukocidin

Toxin produced by Staphylococcus aureus that kills macrophages and helps evade immune response

Coagulase positive

Staphylococcus aureus produces the enzyme coagulase which helps it clot plasma and avoid immune defenses

Peptidoglycan layer resistance

Thick cell wall helps Staphylococcus aureus resist lysozyme digestion

Reinfection ability

Infections can occur again even if antibodies are already present

Superantigens

Some strains overstimulate the immune system causing excessive inflammation(staphylococcus)

Asymptomatic carriers

Many hospital workers carry Staphylococcus aureus without showing symptom

Impetigo

A pus forming skin infection

Impetigo is caused by

streptococcus pyogenes, staphylococcus, or both

Exfoliative toxins A and B (scalded skin syndrome)

Produced by Staphylococcus aureus and responsible for certain skin infections

Toxin genetic origin (scalded skin syndrome)

One exfoliative toxin is plasmid encoded while the other is chromosomally encoded

Toxin B spread (scalded skin syndrome)

Travels through the bloodstream and affects skin throughout the body

Skin damage from toxin B (scalded skin syndrome)

Causes widespread damage to the skin leading to peeling or blistering

Newborn impetigo (scalded skin syndrome)

Skin infection in infants that can be caused by exfoliative toxins produced by Staphylococcus aureu

Toxic Shock Syndrome (TSS)

A life threatening condition caused by Staphylococcus aureus infection

TSST-1 toxin

Toxin produced by Staphylococcus aureus that causes toxic shock syndrome

Superantigen activity (toxin shock syndrome)

TSST-1 overstimulates the immune system leading to excessive immune response

Systemic circulation (toxin shock syndrome)

The toxin enters the bloodstream and spreads throughout the body

Effects of TSS

Can lead to shock and organ failure due to widespread immune activatio

Group A Streptococcus

Streptococcus pyogenes causes several infections

Strep throat

A common throat infection caused by Streptococcus pyogenes

Scarlet fever

Caused by an erythrogenic toxin produced by Streptococcus pyogenes

Erythrogenic toxin

Produced by Streptococcus pyogenes and carried on a prophage which leads to scarlet fever

Hemolysins

Virulence factors that lyse red blood cells

Streptolysin

A toxin that damages host cells and contributes to tissue destruction

M protein

A surface protein that helps bacteria evade the immune system

Capsule

Protective layer that helps Streptococcus pyogenes avoid phagocytosis

Streptokinase

Enzyme that breaks down blood clots to help bacteria spread

Hyaluronidase

Enzyme that breaks down connective tissue to allow bacterial spread

Erysipelas

A skin infection caused by Streptococcus pyogenes

Necrotizing fasciitis

A severe infection that destroys soft tissue caused by Streptococcus pyogenes

Streptococcal toxic shock syndrome

A life threatening condition caused by toxins from Streptococcus pyogene

Propionibacterium acnes

Anaerobic bacterium associated with acne

Anaerobic growth

Thrives in low oxygen environments such as clogged pores

Sebaceous gland activity

Excess oil production provides nutrients for bacterial growth

Bacterial overgrowth

Increased nutrients allow rapid multiplication of Propionibacterium acnes

Pore blockage

Oil and bacterial buildup clog pores

Inflammation and tissue damage

Bacterial activity triggers inflammation leading to skin damag

Pseudomonas dermatitis

Infection often caused by Pseudomonas aeruginosa affecting the skin

Pseudomonas aeruginosa

A bacterium known for high resistance to antibiotics and disinfectants

Antibiotic resistance (pseudomonas aeruginosa)

This bacterium is difficult to treat due to strong resistance mechanisms

Exotoxins

Produced by Pseudomonas aeruginosa and contribute to tissue damage

Biofilm formation

Allows the bacteria to adhere to surfaces and resist treatment

Endotoxin

A component of the bacterial cell wall that triggers inflammation

Burn patient infections

Pseudomonas aeruginosa commonly infects individuals with burn injurie

Ophthalmia neonatorum

Newborn conjunctivitis occurring shortly after birth

Cause of infection (Ophthalmia neonatorum)

Commonly caused by Neisseria gonorrhoeae or Chlamydia trachomatis

Transmission (Ophthalmia neonatorum)

Infection is acquired from the birth canal during delivery

Neisseria gonorrhoeae

A bacterial cause of severe eye infection in newborns

Chlamydia trachomatis

A bacterial cause of conjunctivitis in newborns

Treatment (Ophthalmia neonatorum)

Prevented or treated using silver nitrate or tetracycline eye preparation

Bacterial conjunctivitis (Pink Eye)

An eye infection caused by bacteria leading to redness and irritation

Causes of infection (Bacterial conjunctivitis)

Can be caused by Staphylococcus Streptococcus Neisseria Haemophilus influenzae or Pseudomonas

Treatment (Bacterial conjunctivitis)

Treated with sulfonamide ointments

Trachoma

An eye infection caused by Chlamydia trachomatis leading to swollen conjunctiva

Chlamydia trachomatis (Trachoma)

The bacterium responsible for causing trachoma

Effects of infection (Trachoma)

Can lead to blindness if left untreated

Inward eyelashes (Trachoma)

Eyelashes turn inward and damage the cornea causing irritation and injur

Urinary tract infections (UTIs)

Infections of the urinary system that can affect different structures

Types of infection (UTIs)

Can be ascending from the urethra or descending from the kidneys

Escherichia coli (UTIs)

The most common cause of urinary tract infections

Proteus (UTIs)

A bacterial genus that can also cause UTIs

Klebsiella (UTIs)

Another bacterial genus that can cause UTIs

Hospital acquired UTIs

Often occur in healthcare settings due to catheter us

Bacterial vaginitis

A vaginal infection caused by imbalance in normal flora

Increased vaginal pH (Bacterial vaginitis)

Higher pH allows harmful bacteria to grow

Gardnerella vaginalis (Bacterial vaginitis)

A key bacterium involved in the infection

Anaerobes (Bacterial vaginitis)

Other low oxygen bacteria that contribute to overgrowth

Clue cells (Bacterial vaginitis)

Vaginal epithelial cells coated with bacteria used for diagnosi

Gonorrhea

A sexually transmitted infection caused by Neisseria gonorrhoeae

Neisseria gonorrhoeae (Gonorrhea)

The bacterium responsible for causing gonorrhea

Virulence factors (Gonorrhea)

Includes pili endotoxin Opa proteins and IgA protease

Immune evasion (Gonorrhea)

Can survive inside immune cells

Pelvic inflammatory disease (Gonorrhea)

A complication affecting reproductive organs

Human only host (Gonorrhea)

Humans are the only natural host

Asymptomatic carriers (Gonorrhea)

Individuals can spread infection without symptoms

Syphilis

A sexually transmitted infection caused by Treponema pallidum

Treponema pallidum (Syphilis)

The bacterium responsible for syphilis

Stages of disease (Syphilis)

Includes incubation primary chancre secondary rash latent and tertiary organ damage stages

Placental transmission (Syphilis)

Can cross the placenta and infect the fetus

Chlamydia

A sexually transmitted infection caused by Chlamydia trachomatis

Chlamydia trachomatis (Chlamydia)

An intracellular bacterium responsible for infection

Intracellular growth (Chlamydia)

Lives and replicates inside host cells

Nongonococcal urethritis (Chlamydia)

A common manifestation affecting the urethra

Pelvic inflammatory disease (Chlamydia)

A complication affecting reproductive organs

Diphtheria

A respiratory infection caused by Corynebacterium diphtheriae

Corynebacterium diphtheriae (Diphtheria)

The bacterium responsible for diphtheria

Exotoxin (Diphtheria)

Blocks protein synthesis in host cells

Pseudomembrane formation (Diphtheria)

Forms a thick membrane in the airway that can block breathing

Prevention (Diphtheria)

Prevented by DTP vaccine

Whooping cough (Pertussis)

A respiratory infection caused by Bordetella pertussis

Bordetella pertussis (Pertussis)

The bacterium responsible for whooping cough

Toxin production (Pertussis)

Produces toxins that damage respiratory tissues

Stages of disease (Pertussis)

Includes catarrhal paroxysmal and convalescent stages

Pneumonia

A lung infection commonly caused by Streptococcus pneumoniae

Streptococcus pneumoniae (Pneumonia)

The bacterium most commonly responsible