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
What is aggregation of PRP-res in the brain?
Amyloid fiber formation (fibril)- neuronal cell death- astrocyte “clean up”, because there are holes left in the brain after.
What is spongiform/prion disease?
“Spongiform” changes in the brain and causes progressive neurodegeneration.
Symptoms: rapidly progressive dementia, ataxia (loss of coordination), myoclonus (involuntary jerking movements), behavioral changes and insomnia
Course: Rapid progression over wks to months. Uniformly fatal outcome
How can we contract spongiform/prion disease?
By eating infected tissue, inheriting mutations in the prion protein gene, or spontaneous formation of PrP-res.
What is the anatomy of lymph nodes?
Lymph nodes dump fluid into veins. Lateral transport from SI to bloodstream. Fibroblast in loose connective tissue anchors lymph nodes. The endothelial cells have a flaplike minivalve that are loosely joined cells at capillary walls that when there is an increase in interstitial fluid, it pushes the valves open. The filaments anchored to connective tissue anchor the node to surrounding structures and help the valve open with interstitial fluid as well. Where B and T APCs are.
What is the physiology of lymph nodes?
Lymph flows through the lymphatic capillaries, collecting lymphatic vessels, lymphatic trunks, and lymphatic ducts, it may flow through several lymph nodes along the way. It helps to maintain blood volume lymoh nodes have low pressure, so skeletal help lymph move.
Immobilize people after surgery. Keep lymph in an area to keep immune components theres to speed up recovery.
What are lymphatic trunks?
Formed by the union of largest collecting vessels, drain largest areas of collecting vessels, drain large areas of body. Named for regions of the body they drain: paired lumbar, paired bronchomediastinal,paired subclavian, paired jugular trunks, and single intestinal trunk. The cisterna chyli is the node in the abdominal cavity.
What are the responsibilities of the right lymphatic duct and thoracic duct?
Right lymphatic duct: drains lymph from the upper limb, and the right side of the head and thorax. Empties into the blood at the junction of the right internal jugular and subclavian veins.
Thoracic duct: drains lymph from the rest of the body. Empties into the blood at the junction of the left internal jugular and subclavian veins
Why do T cells need to mature?
T cells need to mature for immunocompetence and self-tolerance.
What are the primary lymphoid organs?
Initial site of lymphocyte development, which supply the secondary lymphoid organs with mature by naive lymphocytes
Thymus- where t cells mature
Red bone marrow- where T and B cells are made
What are the secondary lymphoid organs?
Lymph nodes, tonsils, spleen, Peyer’s patches, and appendix.
What do the cervical lymph nodes look like?
Cervical lymph nodes are typically swollen and inflamed during infections.
What are MALT lymph organs?
Mucosa-associated lymphoid tissues
Tonsils, Peyer’s patches, and appendix, see some in respiratory tract, GI/GU
What are the four types of tonsils?
Pharyngeal (adenoids), Tubal, Palatine (largest), and Lingual.
What are Peyer’s patches?
Peyer’s patches are lymphoid tissues in the small intestine that build memory of bacteria.
What is the spleen’s role as a secondary lymph organ?
White pulp: immune response and proliferation. Storage of platelets
Red pulp: in babies essential RBC production
Splenic infarct can kill someone- happens in mono
Splenic infarct: can kill someone and happens in mono
What is the thymus as a primary lymph organ?
Bilobed where T cells matures and defining self vs. nonself. It shrinks with age. The blood thymus barrier. T cells mature as the enter the medulla (cortex to medulla, outer to inner) reg T cells are in the thymus corpuscle
What is red bone marrow’s role as a primary lymphoid organ?
Red bone marrow is where T and B cells are produced.
What is lymphedema?
Prevents normal return of lymph. Tumors and obesity play roles, pannus: compression from abdominal fat, whole leg
What is lymphangitis?
Streaking red marks where lymph node lines are swollen
What are acid-fast bacteria?
Acid-fast bacteria include Mycobacterium and Nocardia.
What is immunology?
The study of defenses the body uses to recognize itself from nonself (foreign) substances or cells; the immune system destroys or renders harmless foreign matter.
What are the functions of immune defense mechanisms?
Protection against infection by various types of pathogens: virus, microbes (bacteria, fungi. parasites). Isolate and remove foreign substances that are not microbial. Destroy cancer cells that may arise (immune surveillance)
What are some examples of mucous membranes?
Intact skin epidermis: acid mantle of skin and keratin
Intact mucous membranes: mucus, nasal hairs, cilia, gastric juice, acid mantle of vagina, lacrimal secretion (tears), saliva, urine
What are TLRs?
Recognize pathogen associated molecular patterns on invading microorganisms (PAMPs) and damage associated molecular patterns from damaged host cells (DAMPs)
What is the adaptive immune response?
It is specific and depends on specific recognition by lymphocytes of the substance or cells to be attacked