Microbiology: Understanding Viruses, Fungi, Protists, and Bacteria

Name:

General:

Symptoms:

Treatments:

SARS-CoV-2

• Positive sense, single-stranded RNA

• Enters human cells by binding to ACE2

• Airborne disease

• 60-140 nanometers

• Fever/Chills

• Loss of taste and smell

• Severe dry cough

• Shortness of breath

• Acetaminophen

• Ibuprofen

• Nirmatrelvir

• Remdesiver

• Molnupiravir

HIV

• Infects T-cells, macrophages, and dendritic cells

• Single-stranded positive sense RNA virus

• Retrovirus (lentivirus)

• 120 nm

• Swollen lymph nodes

• Night sweats

• Muscle aches

• Mouth ulcers

• Fever

• Abacavir

• Emtricitabine

• Lamivudine

• Zidovudine

• (These are all NRTIs – Nucleotide Reverse Transcriptase Inhibitors)

Influenza A

• Causes flu in birds and humans

• Negative sense single-stranded RNA virus

• Subtypes are classified based on the H and N antigens (H is hemagglutinin, 18 found)

• (N is neuraminidase, 11 found) e.g. H17N10

• 80-120 nm

• Filamentous virions

• Headache

• Fatigue

• Rhinitis

• Chills

• Myalgia

• Oseltamivir

• Zanamivir

• Peramivir

• Baloxavir

• Ibuprofen

• Acetaminophen

Hepatitis B

• Affects liver

• Transmitted by exposure to infectious blood or fluids

• Negative sense, partially double-stranded DNA

• Pararetrovirus (non-retrovirus but uses reverse transcription)

• Fever

• Weakness

• Fatigue

• Nausea

• Yellowish skin

• Abdominal pain

• Symptoms appear after 30-180 days

• Acute: few weeks

• Chronic: up to 6 months

• Tenofovir

• Entecavir

• Lamivudine

• Eating a healthy diet, drinking more fluids, rest

• There is no real treatment

T4 Phage

• AKA Escherichia virus T4

• Bacteriophage that infects E. coli

• Double-stranded DNA

• 90nm by 120 nm

• T4 tail is hollow to pass nucleic acid into host cell

• Only infects E. coli, so no symptoms for humans

• Phages infect bacteria, so they are very helpful for protecting the gut from attacks of deadly bacteria

• N/A

Name:

General:

Symptoms:

Treatments:

Candida auris

• In the phylum Ascomycota

• Grows as a yeast

• Causes candidiasis

• Infects bloodstream, internal organs, central nervous system

• Shiny, smooth, whitish-gray viscous colonies

• Ellipsoid

• Spreads fast among healthcare patients

• Lives on surfaces for multiple weeks

• Resistant to many antifungal antibiotics

• Feeling fullness in ear

• Pain and pressure in ear

• Fever

• Chills

• Low BP

• High heart rate

• Lethargy

• Low body temperature

• Really dangerous

• Spreads fast among patients

• Echinocandins

• Treatments are complicated as it is commonly misidentified as other Candida species

Alternaria solani

• Causes disease in tomato and potato plants (early blight)

• Produces concentric brown/black circles on leaves (typically center for potatoes)

• Causes stem lesions and fruit rot

• Symptoms start on the older leaves

• Area around leaf spot may become yellow and chlorotic

• Small brownish/blackish lesions

• Yellowish leaves

• Cankers on tomato stems

• Dry spots on fruit

• Preventing wetness on leaves and applying fungicides

Name:

General:

Symptoms:

Treatments:

Plasmodium falciparum

• Unicellular parasite

• Deadliest species of Plasmodium that causes malaria in humans

• Transmitted through bite of female Anopheles mosquito

• Sporozoites are released from mosquitoes to enter into the skin during feeding.

• It multiplies in blood and clogs blood vessels, and infects RBCs and causes host immunity to hemolyze non-infected RBCs

• Fever

• Sweats

• Chills

• Headache

• Malaise

• Nausea

• Vomiting

• Muscle aches

• Artemether-lumefantrine

• Mefloquine

• Quinine sulfate + clindamycin

Giardia duodenalis

• Colonizes small intestine causing giardiasis

• It attaches to intestinal epithelium and reproduces by binary fission

• Doesn’t spread to other parts of gastrointestinal tract

• Possible to survive even outside host

• 2 life stages: trophozoite and cyst

• Cysts are oval-elliptical

• 8-19 micrometer (10-14 avg)

• Diarrhea

• Gas

• Stomach pain

• Nausea

• Dehydration

• Bloating

• Weight loss

• Most people don’t have any symptoms until 1-2 weeks

• Giardia typically lasts for 2-6 weeks

• Metronidazole

• Tinidazole

• Nitazoxanide

• Paromomycin

• Quinacrine

• Furazolidone

Name:

General:

Symptoms: (of a disease caused by these proteins)

Treatments:

PrP

• Exists in 2 forms: PrPC, PrPSc

• Mostly in nervous system but is throughout the body

• Believed to be important in synaptic development

• And stabilizing structure of synapse and establishing memory

PrPC: Creutzfeldt-Jakob disease, Gerstmann-Straussler-Scheinker syndrome, fatal familial insomnia.

PrPSc: Scrapie, Kuru, bovine spongiform encephalopathy

• Memory loss

• Impaired thinking

• Imbalance/Incoordination

• Decline in intellectual functions

• Depression/Anxiety

• Changes in personality/behavior

• NO TREATMENTS

• …but some things to HELP, are:

• Chemotherapeutic approaches

• Antisense therapy

• RNA therapeutic approaches

Amyloid beta

• Peptide byproduct of normal brain function

• Key component of Aβ plaques

• Aβ molecules build up and damage blood vessel walls in the brain – causing brain bleeds and cognitive impairment

• Aβ protein accumulation leads to synaptic dysfunction, inflammation, and eventually dementia

• Feeling weak and tired

• Losing weight unpurposefully

• Skin bruises easily

• Amyloid beta can cause: Alzheimer’s, cancer, Down syndrome

• Lecanemab

• Donepezil

• Aducanumab

Any monoclonal antibodies (as they prevent amyloid beta plaque forming)

Name:

General/How it Survives:

How it Survives:

Acidophiles:

• Prefer to live in areas with very low pH (usually pH < 3)

• Change their cell membrane to incorporate substances such as fatty acids that protect the cell.

• Secrete a biofilm to slow down the diffusion of molecules into the cell.

• Highly impermeable cell membranes to retard the influx of protons into the cell.

• Secrete acid outside of the cell to maintain a pH gradient.

• Mechanisms to pump protons out of the intracellular space to keep cytoplasm at neutral pH

• Lipid composition of the cytoplasmic membrane to reduce the permeability to protons.

Alkaliphiles:

• Prefer to live in areas with very high pH (usually pH > 9)

• Maintaining a relatively low alkaline level of about 8 pH inside their cells.

• Maintaining cytoplasmic pH homeostasis

• Evolutionary modification of lipid and protein structure

• Increased expression and activity of monovalent cation/proton antiporters

• Increased metabolic acid production through amino acid deaminases and sugar fermentation

• Increased ATP synthase that couples H+ entry to ATP generation

Capnophiles:

• Inhabit environments with very high concentrations of carbon dioxide (CO2).

• Have a metabolic requirement for carbon dioxide

• Formation of cysts and spores

• Changes in cellular membranes

• Expression of repair enzymes for damage

• Synthesis of molecules for relieving stresses

Halophiles:

• Highly tolerant to environments with high salt concentrations, such as salt lakes.

• Prevent water loss by increasing the internal osmolarity of the cell.

• Osmoprotectants balance the internal and external osmotic pressure, making the two solutions isotonic.

• Halophiles increase the osmotic activity of cytoplasm with the external environment to maintain equilibrium.

• Halophiles have a protective layer of mucilage.

• Halophiles have certain lipids such as diacidic phospholipid in the cell membranes.

• Halophilic proteins display specific biophysical adaptation properties to high salt.

Osmophiles:

• Organisms that live in areas with very high osmotic pressure

• Produce osmoprotectants (like amino acids and alcohols). These solutes increase osmotic pressure inside the cell to balance the turgor pressure on the cell from the outside environment

• Accumulate compatible solutes intracellularly to maintain osmotic balance in response to decreased water availability.

Psychrophiles:

• Extremophilic organisms that grow at temperatures -20°C to 20°C

• Producing antifreeze proteins

• Producing cryoprotectants

• Secreting cold shock proteins

• Adjusting the structure of enzymes

• Activating secondary metabolic pathways

• Altering membrane fluidity

Thermophiles:

• Microorganisms prefer very high-temperature environments.

• Considered to live between 45-80°C (sometimes the lower end of the range is stated as closer to 50°C)

• Organisms that grow best above 80°C are called hyperthermophiles

• Thermophiles can also survive by getting lots of potassium and magnesium salts.

• Thermophiles have enzymes called thermozymes that work at high temperatures

• Thermophiles have heat-resistant protein molecules.

• Thermophiles’ DNA is also adapted to high temperatures. Thermophilic archaea have higher levels of potassium and magnesium salts, which protect their DNA from degradation.

Name:

General:

Symptoms:

Treatments:

Vibrio Cholerae

• Gram-negative, facultative anaerobe

• Secretes a toxin that leads to water loss in the intestines

• Attaches itself to copepods, small crustaceans in plankton

• Most other species are halophiles

• Vomiting

• Watery diarrhea

• Thirst

• Leg cramps

• Restlessness

• Drinking contaminated water or ingestion of food with fecal matter from infected people

• Ringer’s lactate and oral rehydration solution combined with antibiotics such as fluoroquinolones and tetracyclines

• Rehydration therapy

Rickettsia rickettsii

• Gram-, intracellular aerobic coccobacillus

• Lives in cytoplasm of eukaryotes

• Ixodidae (hard-bodied) ticks carry the disease

• Tick becomes infected when feeding off blood of infected host

• Fever

• Rash

• Muscle pain

• Nausea

• Stomach pain

• Causes Rocky Mountain Spotted Fever

• Tick bite transmits disease

• Tick can transmit disease while mating and having kids

• Doxycycline

• Empiric therapy

Streptococcus pneumoniae

• Gram+, spherical

• Usually found in diplococci

• Non-spore forming

• Resides asymptotically in respiratory tract, sinus and nasal cavity

• Main cause of pneumonia and meningitis, and sepsis for those in HIV

• Fever

• Stiff neck

• Increased sensitivity to lights

• Ear pain

• Chills

• Chest pain

• Joint pain

• Penicillin

• Amoxicillin

• Broad-spectrum antibiotics

(aka pneumococcal diseases)

Corynebacterium diphtheriae

• Usually harmless until a bacteriophage that carries a gene that activates toxin (this toxin causes disease)

• Causes pseudomembrane to form over the respiratory mucosa

• Caused by penetration of bacteria into mucosal layers

• Gram+, highly pleomorphic, club-shaped, non-motile, non-sporulating bacteria.

• (Often looking like Chinese letters)

• Thick, gray membrane covering throat and tonsils

• Sore throat

• Swollen glands in throat

• Difficulty breathing, restricted airway

• Fever/Chills

• Causes diphtheria

• (aka Klebs-Löffler bacillus)

    DIFFICULTY BREATHING

• Erythromycin

• Penicillin

• Diptheriae antitoxin

MRSA

• Gram+, coccus, cluster forming

• MRSA is any strain of S. aureus that has developed a resistance to Beta-lactam antibiotics (broad spectrum antibiotics that include some penams and cephems)

• Common in hospitals, prisons, nursing homes

• Can cause a range of health problems, such as skin infections, pneumonia, sepsis

• Fever

• Chills

• Redness

• Pus-filled boils and sores

• Penams are a derivative of penicillin (methicillin, oxacillin, etc)

• Anywhere that has ppl w/ open wounds, invasive devices, and ppl w/ weak immune systems

• Trimethoprim-sulfamethoxazole 

• Clindamycin

• Minocycline

• Linezolid

• Intravenous antibiotic treatment

• Drain abscess at doctor’s office

Mycobacterium tuberculosis

• Unusual waxy coating on cell surface due to mycolic acid- creates it hard to gram stain

• Weakly gram+, muy aerobic, needs high levels of oxygen

• Infects the lungs

• Humans are the only known reservoirs of it

• Spreads by air droplets from infected person

• Rod shaped bacteria, acid fast 

• Cough (maybe bloody)

• Weight loss

• Fever

• Difficulty breathing

• Isoniazid 

• Rifampin

• Pyrazinamide

• Ethambutol 

• Streptomycin