Infectious Diseases Flashcards
A weekly drug used as chemoprophylaxis for malaria
Contraindications
Mefloquine
Neuropsychiatric disorders, conduction abnormalities, epilepsy
Severe malaria characterisitics
Reduced GCS, jaundice, oliguria, hypoglycaemia*, APO
Cancer associated with chronic typhoid infection
Gallbladder carcinoma
Gene conferring colistin resistance
MCR-1
EBV Oncogenic gene
Associated Cancers
LMP-1
Post-transplant lymphoproliferative disorders (small intestine, lung highest) NP cancer Hodgkin's lymphoma Gastric Carcinoma Oral hairy leukopaenia
Drug associated with hypersensitivity reaction associated with HLAB5701
Abacavir (NRTI)
Abacavir binds to the ‘‘self-peptides’’ of the MHC1 of HLA5701, altering its structure -> triggers a cytotoxic T cell response
HLA-B*57.01 have more effective cytotoxic responses against HIV than people with other HLA types
Virulence factor of staph auerus associated with skin and soft tissue and nectrotising pneumonia
Panton-Valentine Leucocidin toxin
TB meningitis altered regimen
Moxifloxacin is better than ethambutol for CSF penetration
9-12 months therapy
Dexamethasone early to reduce risk of IRIS
Enterococci species sensitive to amoxicillin
E. Faecalis
AmpC gene
ESCAPPM beta lactamase gene
CRE treatment
Colostin
Tigecycline
High dose carbepenam
Aztreonam
Ceftazadime avibactam
KPC resistant organisms
NDM resistance drug
Colostin
Treatment of aspergillosis
Voriconazole
Benching filamentous fungi with branching hyphae
Aspergillis
Antibiotics that acts by binding to DD-transpeptidase, inhibiting its cross-linking activity and preventing new cell wall formation
Penicillin
Malaria species with hypnozites
Plasmodium ovale and Plasmodium vivax
Medication that treats malarial hypnozites
Primaquine
Cephalosporins with activity against pseudomonas
Ceftazidime
Cefepime
5th generation cephalosporin that has activity against MRSA
Ceftaroline
pharmacokinetic/pharmacodynamic mechanism best determines the clinical efficacy of penicillin based antibiotics
Time above MIC
What is the mechanism by which carbapenemase-producing gram negative organisms confer resistance to meropenem?
Inactivation by hydrolysing beta-lactamases
Action of integrase inhibitor
Prevent binding of preintegration complex (PIC) to host cell DNA preventing rna production
Raltegravir
Dolutegravir
SE: well tolertared
Weight gain
Action of protease inhibitors
Stop cleavage of gag-pol poly proteins resulting in immature virions
Darunavir
Atalazanavir
Metabolic SEs
Hepatotoxic
Action NNRTIs
Prevent reverse transcriptase from adding néw nucleotides to the chain
Efavirenz
Etravirine
Nevirapine
NRTIs action
Inhibits viral replication by competitively binding reverse transcriptase (false nucleotide)
Abacavir Tenofavir Lamivudine Emtricitabine Zidovudine
SE: mitochondrial toxicity (peripheral neuropathy, pancreatitis, lipoatrophy, hepatic steatosis
abacavir- CV events
Parasitic cause of eisinophilic encephalitis
Angiostrongylus cantonensis
Culture negative infection with systemic features post cardiac surgery
Mycobacterium
New antibiotic treatment for C Diff
fidaxomicin
Screening test for syphilis
EIA
Confirmatory test for syphillis
TPHA/TPPA
VDRL/RPR test (can be used for monitorig disease activity)
Empiric therapy of bacterial meningitis
IV Dexamethason IV ceftriaxone or cefotaxime Add IV benpen for listeria if - Over 50 - immunocompromised - pregnant IV vanc if pneumococcal risk - otitis/sinusitis, mastoiditis
Treatment of Step Pneumo meningitis
IV ceftriaxone and vanc if MIC >1.5
IV dexamethasone
Drugs that should not be used to treat brain abscesses
Aminoglycosides, erythromycin, tetracyclines, clindamycin, and first generation cephalosporins should not be used to treat brain abscess because these drugs do not cross the blood brain barrier at high concentrations
Strep involved in dental disease
strep viridans
Culutre negative endocarditis organisms
Coxiella burnetti
Bortenella
chlamydia
Legionella
Rx: ceftriaxone and gentamicin
IE empiric treatment
Flucloxacillin + Ben Pen+ Gentamicin
or
Vancomycin + Gentamicin
MAC treatment
clarithromycin or azithromycin PLUS rifampicin
rifabutin PLUS ethambutol.
Heart abnormalities/conditions for which preventative antibiotics are recommended
– A prosthetic heart valve
– Valve repair with prosthetic material
- Rheumatic valve
– A prior history of infective endocarditis
– Many congenital (from birth) heart abnormalities
Procedures for which high risk patients should have prophylactic antibiotics for
Dental procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa; this includes routine dental cleaning.
Tonsillectomy/adenoidectomy
Surgery. atsite of an established infection
Treatment of malaria
P.vivax, ovale, malariae: – chloroquine/hydroxychloroquine (3 day course)
P.vivax (chloroquine resistant)
– Arthemether–lumafantrine (Riamet) first line in indonesia, timor,PNG, solomon island, vanuatu. 3 days
– primaquine as anti relapse therapy for 14 days after chloroquine
P.falciparum
– Arthemether-lumafrantine (Riamet) for 3 days is first line – Atorvaquone-Proguanil (Malarone) is second line
– Quinine and doxycycline for 7 days is third line.
– IV artesunate for severe malaria(jaundice,reduced LOC,oliguria,anemia,pulmonary edema,hypoglycemia)
– use quinine and clindamycin if pregnant.
Treatment of schistosomiasis
Praziquantel
Treatment of amaebic liver abscess
metronidazole /tinidazole and paromomycin.
High risk HPV
16, 18
Live vaccines
MMR Oral polio VZV/Zoster Yellow Oral typhoid BCG
Mechanism of MRSA resistance
mecA gene for penicillin-binding protein
PBP-2a - Reduced affinity for beta-lactam drug binding
Not enzymatic, can’t be overcome by beta-lactamase inhibitor
Linezolid mechanism and side effects
Inhibits protein synthesis, binds to 50s ribosomal subunit
Bacterostatic
Good bioavailability and CNS/bone penetration
SE: Reversible bone marrow suppression, irreversible neurotoxicity, optic neuropathy (rare) , serotinin syndrome
Daptomycin MOA and SE
Bacteriocidal antibiotic causes depolarisation of bacterial cell membrane
SE: Myopathy, peripheral neuropathy, eosinophilic pneumonia
Tigecycline
Bacterostatic
Binds to 30s subunit of ribosome, protein synthesis inhibitor
high volume of distribution
Ceftaroline MOA and utility
5th gen cephalosporin with high affinity for PBP-2a
Mechanism of strep pneumoniae penicillin resistance
Alteration of PBP (transpeptidase enzyme)
Can be overcome by increasing dose (not in CNS infections)
Mechanism of strep pneumoniea macrolide resistance
mefA gene - efflux pump
ermB gene - alteration of binding site
Carbapenam resistant organisms
KPC (Kleb pneumonia carbapenemase) NDM-1 (New Delhi- metallo-beta-lactamase) OXA (oxacillin-type BL - Tur key) VIM IMP
ECHAPPM organisms
Gram negatives!
Enterobacter
Serratia marcescens
Citrobacter freudii
Hafnia alvei Acinetobacter and aeromonas proteus vulgaris providencia morganella morganii
Mechanisms of ESCAPPM resistance
AmpC gene on chromosomes or plasmids encodes for beta-lactamases
Treatment of ESCAPPM
Carbapenems
Cefepime
Mechanism of ESBLs
Group of enzymes that hydrolzyse all penicillins, cephalosporins (including cefepime) and aztreonam
Genes are carried on plasmids
TEM1, TEM2, SHV1, CTX-M
Organisms that commonly carry ESBL
E.Coli
Klebsiella
Treatment of ESBL
Carbapenams
Treatment of CRE
Colistin
High dose tigeycline
Aminoglycasides
High dose carbapenamse
Beta-lactamase inhibitors
Clauvulonic acid
Tazobactam
- Preferentially binds BL
Avibatam - - inactivetes
Mechanism of Staph aureus resistance to vancomycin
VanA gene acquired from enterococci via conjugation - plasmid-mediated transfer
encodes D-ala-D-ala -> D-ala-D-lac;substitution of a;anine for lactate
Treatment of Enterococcus faecium
Majority are resistant to penicillin/amoxi
All Enterococci resistant to cephalosporins
Treat with vancomycin or teicoplanin
Common cause or aeseptic meningitis
Enterovirus
When would dolutegravir + lamivudine not be used
VL >500,000, HBV coinfection, pregnant woman
Treatment of candidaemia
Caspofungin (Echinocandin)
Treatment of Cryptococcus
Amphotericin (polyene) + Flucytosine
Treatment of aspergillus (septate mould)
Voriconazole
Treatment of mucor(non-septate)/fusarium
Amphotericin
Highest risk of CMV in allogenic SCT patients
CMV D-/R+
Highest risk patient group in solid organ transplant
CMV D+/R-
Treatment of PJP
Trimethoprim-sulfamethoxazole (TMP-SMX)
Steroids if pO2 <70mmHg/ hypoxia
ART should commence 2 weeks post-therapy
mechanism by which strep pyogenes causes valvular disease in rheumatic fever
Molecular mimicry
PJP prophylaxis in HIV
cotrimoxazole
Asthma and CF associated condition with raised IgE
Allergic Bronchopulmonary Aspergillosis
