PATHOGEN 101
This collection of microorganisms normally lives on or within the human body without causing harm and can even aid in digestion or vitamin production
HUMAN MICROBIOTA
These bacteria are characterized by a thick peptidoglycan layer and the lack of an outer membrane, causing them to appear purple after staining
GRAM-POSITIVE BACTERIA
While naked viruses typically exit a host cell via lysis, these viruses acquire a lipid membrane by "budding" off the host's plasma membrane
ENVELOPED VIRUSES
the host cell to engulf it by injecting effectors
TRIGGER
Antibiotics achieve this by targeting biological features unique to bacteria, such as the cell wall or 30S ribosomes, while leaving host cells unharmed
SELECTIVE TOXICITY
Unlike a primary pathogen, this type of organism only causes disease when the host's immune system is weakened or it enters an unusual part of the body
OPPORTUNISTIC PATHOGEN
This specialized protein complex, often found in Gram-negative bacteria, acts like a tiny syringe to inject effector proteins directly into the host-cell cytoplasm
TYPE 3 SECRETION SYSTEM
Some individuals are naturally resistant to HIV infection because they possess a mutation in this specific co-receptor
CCR5
This term describes the ability of pathogenic fungi to switch between a mold form in the environment and a yeast form inside the host
DIMORPHISM
Antibiotics achieve this by targeting biological features unique to bacteria, such as the cell wall or 30S ribosomes, while leaving host cells unharmed
mechanisms of antibiotic resistance
PARASITISM
This bacterium survives the harsh, acidic environment of the stomach by producing urease to create a local alkaline environment and burrowing into the mucus layer
HELICOBACTER PYLORI
This viral evolution process, common in influenza, involves the sudden "shift" of antigens, often leading to pandemics
ANTIGENIC SHIFT
This bacterium escapes the phagosome and enters the host cytoplasm by producing proteins that disrupt the phagosomal membrane
LISTERIA MONOCYTOGENES
Pathogens like the plague bacterium use these organisms—often insects—to bypass the skin's epithelial barrier and enter the bloodstream
VECTORS
one where only the microbe benefits
COMMENSALISM
HORIZONTAL GENE TRANSFER WITH BACTERIOPHAGES
TRANSDUCTION
Viruses rely on these host-cell motor proteins to travel along tracks to reach specific destinations within the cell
MICROTUBULES
Many intracellular bacteria, like Shigella and Listeria, hijack this host protein to create "tails" for movement through the cytoplasm
ACTIN
Pathogens like HPV and H. pylori are clinically significant not just for infection, but because they can eventually cause this chronic condition
CANCER
Conserved molecular structures found on pathogens, such as LPS, that are recognized by the host's innate immune system
PAMPS
This specific component of the Gram-negative outer membrane can trigger powerful, sometimes dangerous, immune responses in the host
LPS
This viral strategy involves "snatching" the 5' caps from host mRNAs to use as primers for their own viral RNA synthesis
CAP-SNATCHING
This eukaryotic parasite can enter host cells through two methods: one that recruits host lysosomes to the entry site and one that is lysosome-independent
TRYPANSOSOMA CRUZI
This physical defense mechanism involves specialized cells in the respiratory tract that trap and "flush" out microbes
MUCOCILIARY ESCALATOR