Immune response to ListeriaThe human immune response to listeriosis relies on the ¥production of interferon-γ by CD4+ T cells and CD8+ T cells, which activates macrophages and increases the production of reactive oxygen species that are highly toxic to Listeria.
Listeriolysin impairs T cell activation by antigen presenting cells.
+ ☆generates pores in phagosome membranes, which allows it to spread to adjacent cells without reentering the extracellular space microbiologyAmboss level4UWorld new question HirotoShishido
what infection control measures is appropriate for ESBL
genes encoding enzymes are often ☆loaded on plasmids and therefore can be transferred between organisms and between different species through conjugation
carbapenem (eg imipenem) is the treatment of choice for ESBL producing organisms (although unfortunately, organisms with carbapenem resistance have emerged microbiologyAmboss level4UWorld HirotoShishido
salmonella typhi
virulence factorInvasion of enterocytes→ blunted neutrophil response due to capsular antigen Vi→ ☆extensive intracellular replication in macrophages→ spread through lymphatics and RES (reticuloendothelial system) microbiologygastrointestinalUWorld HirotoShishido
rotavirus
location, pathophysiology☆villous epithelium of the duodenum and proximal jejunum
Infection causes diarrhea via multiple mechanisms including ☆villous blunting (loss of absorptive capacity), proliferation of secretory crypt cells (secretory diarrhea), and reduced brush border enzymes.
noninflammatory gastrointestinalmicrobiologyUWorld HirotoShishido
interferon type ⅠType I interferons (α and β) are synthesized by most human cells in response to viral infections.
Once secreted, α and β interferons bind to type I interferon receptors found on infected and neighboring cells.
This results in transcription of antiviral enzymes capable of ☆halting protein synthesis, such as RNase L (endonuclease that degrades all RNA in the cell) and protein kinase R microbiologyUWorld HirotoShishido
two types of cellulitis・Nonpurulent cellulitis is characterized by skin warmth, edema, and erythema with no fluctuant nodules. It is most often caused by beta-hemolytic streptococci ; ☆group A streptococcus (S pyogenes) accounts for the majority of cases.
・purulent cellulitis is characterized by a painful, fluctuant nodule in the dermis or subcutaneus. The most common cause is Staphylococcus aureus; strains that express the virulence factor Panton-Valentine leukocidin microbiologyUWorld HirotoShishido
treatment for this(eggshell calcification→ hydatid cysts)(echinococcus granulosus)
surgery and adjunctive chemotherapy(eg albendazole) are the treatment of choice
cyst manipulation should be performed with caution, as spilling of cyst contents can cause ☆anaphylactic shock microbiologyUWorld HirotoShishido
systemic manifestation of Corynebacterium diphtheriae☆myocarditis/heart failure, neuropathy
myocarditis can also caused by T cruzi(Chagas), Toxoplasma, Borrelia, Mycoplasma, doxorubicin, SLE, ☆dermatomyositis) microbiology HirotoShishido
bacteria which produce dextrans using sucrose as a subtrate
treatment for this conditionviridans steptococci
can adhere to ☆tooth enamel and to ☆fibrin platelet aggregates on damaged heart valves due to their ability to produce insoluble extracellular polysaccharides(dextrans), causing subacute bacterial endocarditis
ethical issues involving HIV infectionreportable
・not required to maintain confidentiality when an HIV-positive patient puts an
identified person at risk by engaging in unprotected sex
・it is acceptable to test the patient for HIV infection even if the patient refuses to consent to the test if a health care provider is exposed to the body fluids of a suspected patient
mechanism of the cavitation in TB(tuberculosis infection)
The release of proteases, nitric oxide, and reactive oxygen species by ☆epitheloid histocytes or multinucleated giant cells helps contain the infection.
However, these compounds also cause ☆extensive collateral tissue damage and can result in the formation of cavitary lung lesions. microbiologyUWorld HirotoShishido
infections whose transmission is related to waterP aeruginosa→ hot tub folliculitis, swimmer's ear
why does acyclovir have only a minimal effect on EBV, CMVEBV and CMV do not produce thymidine kinase(TK) which ☆phosphorylate acyclovir into acyclovir monophosphate(rate limiting step in acyclovir activation) microbiologypharmacologyUWorld HirotoShishido
how does the conversion of nontoxigenic C diphtheriae to toxigenic one occurby bing infected with a lysogenic ☆bacteriophage called Corynephage beta, resulting in the bacterial expression of the diphtheria AB toxin microbiologyUWorld HirotoShishido
dermatophytes
cause of infection☆keratinized matter in the stratum corneum of the superficial epidermis is infected microbiologyUWorld HirotoShishido
brain abscess
common bacteria, single/multipleStaphylococcus aureus, Viridans streptococcus
