Microbio Exam #4: Pathogens

SARS-Cov-2 (Covid-19)

genome/class: ssRNA (+); virus

reservoir: bats/zoonotic

features: large genome, spikes, mutations via rdRNAP

infection mechanism: ACE-2 receptor

treatment (vax?): vax + boosters

adenovirus

genome/class: >50 DNA; virus

reservoir: humans, animals

features: more severe cold that can turn into viral pneumonia and other complications

infection mechanism: respiratory droplets, direct contact

treatment (vax?): not widely given but 2 exist

influenza A

genome/class: ssRNA (-), virus

reservoir: pigs, birds, humans

features: HA and NA spikes, 8 chromosomal segments, mutates with antigenic shift between reservoirs and no proofreading mechanism

infection mechanism: airborne droplets

treatment (vax?): diagnose with serology/qRT-PCR, vaccination and antivirals

measles

genome/class: ssRNA (-); virus

reservoir: humans

features: doesn’t mutate much but infects immune cells

infection mechanism: respiratory droplets, infects B cells and causes agglutination

treatment (vax?): identify with qRT-PCR, vaccination

HIV

genome/class: virus

reservoir: zoonotic

features: mutates, infects immune cells, can reemerge and be latent

infection mechanism: infects nucleated and immune cells

treatment (vax?): detect with serology/assays/qR-PCR, treat with cocktail of inhibitors, no vax

chlamydia

genome/class: bacteria

reservoir: direct contact, humans/zoonotic

features: obligate intracellular parasite, asymptomatic, complications: PID, scarring

infection mechanism:

treatment (vax?): identify with qPCR, not cultureable, antibiotics, no vaccine

tuberculosis

genome/class: bacteria

reservoir: humans, airborne respiratory droplets

features: spontaneous chromosomal mutations (no HGT), slow growing, Mycolic acid cell wall

infection mechanism: respiratory droplets and tubercule formation, overlaps with HIV

treatment (vax?): identify with X-ray or TB test, vax but not in US

c. difficile

genome/class: bacteria

reservoir: feces/surfaces

features: Gram+, strict anaerobe, endospore forming + toxins

infection mechanism: recurrent, lyses intestinal epithelial cells

treatment (vax?): fecal transplant, no vax

e. coli

genome/class: bacteria

reservoir:

features: EHEC (O15:H7 serotype), UPEC, HUS, Shiga-toxin, HGT, plasmids

infection mechanism:

treatment (vax?): UPEC can’t be treated with antibiotics, no vax

candida

genome/class: polymicrobial

reservoir: airborne, gut microbiome

features: moist areas, complication: system wide sepsis

infection mechanism: overgrowth when the microbiome is disrupted, infects skin/mucous membrane, lungs

treatment (vax?): antifungal medication

aspergillus

genome/class: polymicrobial

reservoir: food/soil

features: spores, aflatoxin

infection mechanism: infects the lungs and can disseminate through the body

treatment (vax?): antifungal medication or in extreme complications surgery

plasmodium (malaria)

genome/class: eukaryote

reservoir: humans

features: ring structure, mutating at every replication stage, recurring symptoms as RBCs are destroyed repeatedly

infection mechanism: travels from blood to liver cells, making a ring structure in RBCs, causing artery blockage and low O2

treatment (vax?): vaccine

toxoplasma

genome/class: eukaryote

reservoir: cat feces/undercooked meat

features: invades immune cells, crossing the BBB and leading to brain cysts —> behavior change

infection mechanism: normally asymptomatic unless immunocompromised, affects decision-making

treatment (vax?): identify with indirect serology, no vaccine

rabies

genome/class: virus

reservoir: zoonotic (saliva)

features: 5 genes, neurotropic virus

infection mechanism: central nervous system

treatment (vax?): identifiable with immunofluorescence, post exposure vaccination

staphylcoccus

genome/class: bacteria

reservoir: humans/fomites

features: toxins/superantigens, beta-lactamase, plasmids, MRSA

infection mechanism: increasingly nosocomial, can infect every organ/tissue

treatment (vax?): antibiotics, no vax

streptococcus

genome/class: bacteria

reservoir: humans

features: streptolysins, M proteins, hyaluonic capsule, toxins

infection mechanism: usually infects the throat (pyogenes, mutans, pneumoniae)

treatment (vax?): antibiotics, no vax

pneumonia

genome/class: polymicrobial

reservoir: humans

features: capsule, causes infant mortality

infection mechanism: colonizes URT and competes, infects lung tissue

treatment (vax?): antibiotics (sometimes)

gonorrhea

genome/class: bacteria

reservoir: humans

features: fastidious, massive HGT/naturally competent, survives inside phagocytes; complications: PID, narrow urethra, ectopic pregnancy

infection mechanism: infects phagocytes, infects reproductive tract, mouth/nose/eyes

treatment (vax?): identify with PCR, cultureable for resistance, no vax