ID Flashcards
What are the shapes of gram-positive bacteria?
Clusters (Staphylococci), Rods (Bacillus anthracis), Cocci in chains (Streptococci)Classics: Streptococcus, Enterococcus, Staphylococcus, Bacillus, Clostridium, Corynebacterium, Listeria
Classics: Streptococcus, Enterococcus, Staphylococcus, Bacillus, Clostridium, Corynebacterium, Listeria
What are the shapes of gram-negative bacteria?
Rods and Cocci. Classics: Neisseria (diploid cocci), Moraxella (diploid cocci), Spirochetes (Treponema pallidum- syphilis), Mycobacteria (kind of) TB- acid fast staining
Classics: Neisseria (diploid cocci), Moraxella (diploid cocci), Spirochetes (Treponema pallidum- syphilis), Mycobacteria (kind of) TB- acid fast staining
Why do Clostridium botulinum and Corynebacterium diphtheria have an odd shape?
Clostridium botulinum is classed as rods, but they have a cocci-shaped head that produces spores. Corynebacterium has a dumbbell shape that forms spores “enteric precautions” because it is multi-drug resistant and is a hospital-acquired infection. Clean with soap and water NOT hand sanitizer.
It is multi-drug resistant and is a hospital-acquired infection. Clean with soap and water NOT hand sanitizer.
What is the difference between gram-positive and gram-negative bacteria cell walls?
Gram-positive bacteria stain purple due to their very thick peptidoglycan layer outside of their cell membrane phospholipid bilayer. The peptidoglycan has teichoic acid which is an antigenic determinant, with surface proteins and lipoteichoic acid.
Gram-negative bacteria have a small peptidoglycan layer with the endotoxin lipopolysaccharide (LPS) and surface proteins. They have an outer membrane and cell membrane separated by the peptidoglycan layer.
Gram-positive has surface proteins and lipoteichoic acid.
What factors affect bacterial virulence?
Capsid, slime layer, and biofilm
These factors make bacteria hard to treat and very virulent.
What are endotoxins and exotoxins?
Endotoxin differs from exotoxin in that it is not a protein excreted from cells, but rather is a normal part of the outer membrane that sheds off, especially during cell lysis.
Endotoxins are released when bacteria are broken down.
Exotoxins are released by bacteria an example is tetanus, where a protein is released to cause infection.
Example of exotoxin: tetanus.
What is mycoplasma?
Mycoplasma lacks a cell wall or peptidoglycan layer, making it neither gram-positive nor gram-negative. It has a lipoprotein membrane and can cause erythema multiforme and walking pneumonia.
What are the shapes of bacteria?
Cocci, baceiilus, vibrios, spirochaetes, spirilla. Some bacteria lack a distinct shape
Define transformation of DNA.
Transformation is when a cell takes up exogenous DNA from its environment, integrating it into its genome.
Define conjugation of DNA.
Conjugation is the direct transfer of genetic material (DNA) from one bacterial cell to another through physical contact.
Define transduction of DNA.
Transduction involves a bacteriophage carrying DNA from one bacterium to another.
What are viruses?
They are energy-less and float around until they attach to a host cell. They have a nucleic acid genome (DNA or RNA, single or double-stranded inside the capsid), a protective protein shell called a capsid, and an envelope (impacts virulence, not all viruses have this) Vary in size, shape, and life cycles.
They vary in size, shape, and life cycles.
What are some RNA viruses?
Toga, corona, retro, picorna, calici, reo, flavi, orthomyxo, paramyxo, rhabdo, bunya, arena, filo
Can be negative or positive. Reverse transcription in HIV. RNA to DNA by reverse transcription. DNA to mRNA by transcription. mRNA to enzymes by translation
RNA can be negative or positive, with reverse transcription in HIV.
What are some DNA viruses?
HHAPPy: Herpes, Hepadna, adeno, papova, parvo, and pox. DNA to mRNA by transcription. mRNA to enzymes by translation.
DNA is transcribed to mRNA, which is then translated to enzymes.
What are the stages of viral multiplication?
- Attachment: Phage attaches to host cell. 2. Penetration: Viral DNA enters host. 3. Biosynthesis: Phage DNA replicates. 4. Maturation: New phage particles assemble. 5. Lysis: Cell lyses, releasing phages.
What are yeasts and molds?
Yeasts reproduce by budding, while molds grow as filamentous structures.
Diflucan/Fluconazole works on the chitin cell wall.
What is an India Ink stain used for?
staining of cryptococcus
What are parasites?
AKA protozoa (some may have flagella): Entamoeba histolytic (1,3, eat RBCs, have bloody diarrhea), Giardia lamblia and Cyclospora cayetanesis (non-bloody diarrhea, usually associated with daycares), Cryptosporidium and Isopora belli (immunocompromised pts will get diarrhea)
Other parasites include: malaria, Toxoplasmosis gondii, Pneumocystis carinii
They can cause various types of diarrhea and other infections.
What is Trichomonas vaginalis?
STI is most common in women and causes odorous discharge. Men can be asymptomatic.
Diagnose with a wet prep and microscope.
Diagnosed with a wet prep and microscope.
What are amoebas?
Amoebas are rare infections caused by Naegleria fowleri, Acanthamoeba, and Balamuthia mandrillaris.
What are helminths?
More commonly known as worms and seen most often in kids.
Ingestion of worn eggs: Ascaris lumbricoides, Trichuris trichiura (whipworm), Enterobius vermicularis (pinworm)
Stepping on something outside: Nectar americanus (hookworm) and Strongyloides stercoralis.
What is a prion?
Prions are misfolded proteins (they do not have a capsid or an envelope!!!!!!) and are capable of causing infectious disease by inducing normal proteins to adopt an abnormal structure. They reproduce on their own.
Some key features include: lack nucleic acids (unlike viruses and bacteria) Resistant to standard sterilization methods (heat, radiation, and chemicals)
They lack nucleic acids and are resistant to standard sterilization methods.
What are examples of prion diseases?
Creutzfeldt-Jakob Disease (CJD), Kuru, Bovine Spongiform Encephalopathy (Mad Cow Disease), Fatal Familial Insomnia (FFI).
What is the difference between PrP-sen and PrP-res?
PrP-sen NORMAL sen: sensitive. Brains and neurons. Broken down by the body.
PrP-res is disease causing. “Resistant” to being broken down