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Infectious Disease Lecture w/ Dr. Lichtenberger – 3 January 2012 The Topic of This Lecture Is: How to Dierentiate Organisms  The cell wall structur e determines whether bacter ia stain blue (Gram+) or red (Gram-). o Gram stains also reveal shape and arrangement, along with the presence of PMs. o  ! east can be seen on Gram stains. The"#re cigar-shaped, stain dar$ purple, and larger than PMs.  T o di%erenti ate Gram+ ba cteria, incuba te a cultur e on bloo agar and con&rm with chemical tests. o Staphylococci  are catalase positive, such that the" are able to brea$ down pero'ide.  The onl" stra in of Staph that is coagulase positive is S. aureus. o ll other Gram+ bacteria are catalase negative. The"#re di%erenti ated b" their t"pe of hemol"sis. !"hemolysis is a mild amount of hemol"sis. o not confuse *-hemol"tic with Group Strep. S. pneumoniae is capsule+ optochin sensitive S. viridans are capsule- and resistant. o  The pres ence of a caps ule is ident i&ed b" the #uellung reaction. o ensitivit" to optochin is evaluated via a disc of the antibiotic on the agar. o S. pneumoniae form diplococci S. mutans and other S. viridans ma$e chains. ll *-hemol"tics are bacitracin sensitive. ecent infections "ield a positive / titer. $"hemolysis is complete. /f these Streptococci , onl" S. pyogenes %G&'( is bacitracin sensitive.  These bacter ia are evid enced b" "ellowi ng of the aga r aroun d the cells. 0-hemol"tic Strep reall" li$e to infect infants. S. pyogenes is P!+ (li$e nterococci ).  The Lance)el classi)cation system for Strep is based on 1 carboh"dr ate di%erences. o S. pyogenes is G S. agalactiae is G2 S. !ovis is G. 3now that for tep 4. ote that *"hemolysis is a stupid, awful misnomer. Enterococci  do /T hemol"5e 21s6  T o di%erentiate from Strep, grow them on 7.89 a1l. Gram stain is insu:cient. ;nder previous nomenclature, all nterococci  were labeled as Group Strep. o  The two spor e-forming Gr am+ or ganisms ar e Clostridium and Bacillus. 2oth are rods. pores are resistant to destruction and are seen with a malachite green stain. o  The Gram+ ros we care about are "oryne!acterium (diphtheria, motile) and Listeria (non-motile) .  There is onl" one Gram- coccus< Neisseria. The two strains are di%erentiated b" maltose fermentation. o N. meningitides is able to ferment maltose, while N. gonorrhoeae cannot. 2oth are diplococci. Gram" ros (G,-) are &rst grouped b" their abilit" to ferment lactose on a aconey agar (not blood). o  Those that fer ment lactos e are ntero!acteriaceae, li$e . coli, #le!siella, "itro!acter , and Serratia .  These ar e evidenced b" pin$ colonies on the Mac1on$ e" agar .

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Infectious Disease Lecture w/ Dr. Lichtenberger – 3 January 2012The Topic of This Lecture Is: How to Dierentiate Organisms

 The cell wall structure determines whether bacteria stain blue (Gram+) or red (Gram-).o Gram stains also reveal shape and arrangement, along with the presence of PMs.o  !east can be seen on Gram stains. The"#re cigar-shaped, stain dar$ purple, and

larger than PMs.  To di%erentiate Gram+ bacteria, incubate a culture on bloo agar and con&rm with

chemical tests.o Staphylococci  are catalase positive, such that the" are able to brea$ down

pero'ide.  The onl" strain of Staph that is coagulase positive is S. aureus.

o ll other Gram+ bacteria are catalase negative. The"#re di%erentiated b" their t"peof hemol"sis. !"hemolysis is a mild amount of hemol"sis. o not confuse *-hemol"tic with

Group Strep.• S. pneumoniae is capsule+ optochin sensitive S. viridans are

capsule- and resistant.o  The presence of a capsule is identi&ed b" the #uellung

reaction.o ensitivit" to optochin is evaluated via a disc of the antibiotic on

the agar.o S. pneumoniae form diplococci S. mutans and other S. viridans

ma$e chains.• ll *-hemol"tics are bacitracin sensitive. ecent infections "ield a

positive / titer. $"hemolysis is complete. /f these Streptococci, onl" S. pyogenes %G&'( is

bacitracin sensitive.•  These bacteria are evidenced b" "ellowing of the agar around the cells

• 0-hemol"tic Strep reall" li$e to infect infants. S. pyogenes is P!+ (li$enterococci).

•  The Lance)el classi)cation system for Strep is based on 1

carboh"drate di%erences.o S. pyogenes is G S. agalactiae is G2 S. !ovis is G. 3nowthat for tep 4.

ote that *"hemolysis is a stupid, awful misnomer. Enterococci  do /Themol"5e 21s6

•  To di%erentiate from Strep, grow them on 7.89 a1l. Gram stain isinsu:cient.

• ;nder previous nomenclature, all nterococci were labeled as Group Strep.

o  The two spore-forming Gram+ organisms are Clostridium and Bacillus. 2oth arerods. pores are resistant to destruction and are seen with a malachite green stain.

o  The Gram+ ros we care about are "oryne!acterium (diphtheria, motile) andListeria (non-motile).

 There is onl" one Gram- coccus< Neisseria. The two strains are di%erentiated b" maltosefermentation.

o N. meningitides is able to ferment maltose, while N. gonorrhoeae cannot. 2othare diplococci.

Gram" ros (G,-) are &rst grouped b" their abilit" to ferment lactose on a aconeyagar (not blood).

o  Those that ferment lactose are ntero!acteriaceae, li$e . coli, #le!siella,"itro!acter , and Serratia.  These are evidenced b" pin$ colonies on the Mac1on$e" agar.

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o  Those that don#t ferment lactose are di%erentiated b" the presence of o'idase. Pseudomonas is o'idase positive. Shigella, Salmonella, and $roteus are

o'idase negative.  Three Gram- bacteria have capsules (li$e S. pneumoniae)< H. in%uen&ae, #. pneumoniae,

and '. meningitides. 'ecial culture reuirements6 H. in%uen&ae  chocolate agar with factors = and >.?@ TA@@

o 'eisseria Tha"er-Martin media (. tu!erculosis  ?owenstein-Benser agar.  

TA@@ Legionella  charcoal "east e'tract agar ll fungi  abouraud#s agar.  

 TA@@ T//, C;13  Inia in  is a special stain, used primaril" to identif" Cryptococcus neoformans, whose

capsule bloc$s the in$. &ci"fast stains wor$ for m"cobacteria (including Tb), which lac$ a cell wall.  The Giemsa stain is used to identif" intracellular organisms< $lasmodium, "hlamydia, 

)orrelia, Trypanosome. 'iler stains are used in tissue to identif" fungi (li$e 44 in AD= patients), which stain

blac$. Pigmented bacteria< S. aureus is gold $. aeruginosa is blue-green Serratia marcescens is

rust-colored.

Cungi are &rst divided into "easts ("andida and "ryptococcus) or molds.o C. albicans are the onl" germ tube+ organism. The" li$e to form pseudoh"phae.o Molds are septate ( *spergillus and +usarium), non-septate ((ucor  and ,hi&opus), or

dimorphic. Df it branches at E8°, it#s probabl" *spergillus. Df it branches at F°, it#s

probabl" (ucor . usceptibilit" to antimicrobials is assessed b" the I. /ne method is dis$ di%usion

another is the @-test.o  The micro-dilution techniHue is prett" cool, as a color change from pin$ to purple

indicates the MD1.o number must be loo$ed up in a reference boo$ to determine if the strain is

resistant or not.

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Infectious Disease Lecture w/ Dr. Lichtenberger – 3 January 2012The Topic of This Lecture Is: ,eview of *ntimicro!ials

 The &rst antibiotics were $"lactams, which inhibit cell wall s"nthesis b" bloc$ingpeptidogl"can cross-lin$ing.

o Penicillin resistance is conferred b" a plasmid that carries $"lactamase. laulanic aci is a 0-lactamase inhibitor (e'. 1lavamo'). /thers are

sulbactamIta5obactam.o 4enicillin treats Gram+ cocci rods, and it#s still the &rst line treatment for

spirochetes li$e s"philis. /odles of people can have h"persensitivit" reactions. ome develop

hemol"tic anemias.o &mo5icillin and amicillin treat nterococci, H. in%uen&ae, . coli, Listeria, and

$roteus. ome Staph infections can be treated too, but most of them are resistant b"

now.o ome 0-lactams are penicillinase-resistant J o5acillin, methicillin, nafcillin. The"

treat most S. aureus. Cor to'icit", interstitial nephritis is evidenced b" a s$in rash, elevated 1r,

fever, and  K21.o Most penicillins don#t treat $. aeruginosa, but ieracillin and ticarcillin are

e%ective. Dnterestingl", the" also wor$ against Gs and some anaerobes. D have no

idea wh". ehalosorins are 0-lactams that are less susceptible to penicillinases. There are four

generations.o 4st (cephale'inIcefa5olin)< Gram+ /?! LLL nd (cefmeta5ole)< Gram+, some Gram-,

and anaerobes Nrd gen (cefpo'idime)< Mainl" Gram- LLL E th (cefepime)< Gram+ and resistant

Gram- arbaenems are awesome due to their broad spectrum. The" treat an"thing resistant to

other 0-lactams.o ?i$e cephalosporins, the" can cross-react with P1 allergies. The" don#t wor$

against M. Monobactams li$e a6treonam treat Gram- bugs and nothing else. The" don#t cross-react

with P1. Gl"copeptides li$e ancomycin inhibit cell wall formation b" preventing -la-la

binding.o  The" treat resistant Gram+, especiall" S. aureus (-'&) and nterococci. Dt is /T

orall" active.  The" have absolutel" no e%ect on Gram- bugs or anaerobes.

o  To'ic e%ects include re man synrome (Oust slow the infusion rate),nephroto'icit", and ototo'icit".

minogl"cosides li$e gentamicin and tobram"cin are protein s"nthesis inhibitors used for

resistant Gs.o  The" are well-renowned for their abilit" to cause ototo'icit", murdering innocent

hair cells. 7etracycline and o5ycycline cannot be used in children, as the" stunt bone growth and

ruin enamel.o  The" are used to treat ,ic-ettsiae, spirochetes, (ycoplasma, and "hlamydia.o  Their absorption is minimi5ed if ta$en with mil$. lso, the" can induce

photosensitivit". Macrolides (erythromycin  a6ithromycin) treat at"pical pneumonias, Ts, and Gram+

if P1 can#t be used.

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o lot of patients end up with GD discomfort or diarrhea. erum levels ofanticoagulants ma" increase.

?incosamides (clinamycin) are great for dental infections< Gram+ bugs and anaerobes(/T Gram-).

o Df a patient develops diarrhea after ta$ing clindam"cin, suspect C. dicile colitis. ulfonamides (sulfametho5a6ole) are great for treating ;TDs, 'ocardia, and "hlamydia.

 The" inhibit AP.o 7rimethorim inhibits AC reductase. Dt covers pneumocystis, Shigella, and

Salmonella.o 74"'8 (9actrim) can#t be given to those with G7P de&cienc". There#s ris$ of

nephritis or anemia.  The two drugs wor$ together to completel" inhibit bacterial folate s"nthesis.

CluoroHuinolones (ciro:o5acin) inhibit g"rase. The" mainl" treat Gram- bugs($seudomonas6).

o  The most well-$nown side e%ect is tendonitis, which can lead to tendon rupture(esp. chilles).

etronia6ole creates metabolites to'ic to bacteria. Dt wor$s against anaerobes, li$e ".

dicile.o Dt also treats parasites. s side e%ects, it can cause a metallic taste or nausea if

ta$en with @t/A.

Dt should onl" be given for short periods of time due to neuroto'icit". Khen treating infections, hit earl" and hard with the appropriate antibiotic. 2roader isn#t

alwa"s better.o Minimi5e the length of therap", since to'ic e%ects are more li$el" to appear over

time. n" infection that involves pus is probabl" S. aureus. Tr" o'acillin, 4st gen cephalosporins,

or clindam"cin.o CluoroHuinolones are not e%ective at all. Df it#s M and in the blood, use

vancom"cin. Enterococcus infections can usuall" be treated with amo'icillin or ampicillin, not

cephalosporins.

Strep are usuall" treated b" penicillins, followed b" clindam"cin. on#t use ciproo'acinor macrolides6 @'cept for $seudomonas, Gram" infections are treated b" CQs, 1lavamo',

aminogl"cosides, carbapenemsRo eall", Oust don#t use P1 alone, nor a 4st generation cephalosporin, vancom"cin, or

metronida5ole. Cor Pseudomonas, go with ciproo'acin, aminogl"cosides, piperacillin, a5treonam, or

cefta5idimeIcefepime.o rugs that don#t wor$ are macrolides, clindam"cin, TMP-M>, most cephalosporins,

and 1lavamo'. Cor anaerobes, go with metronida5ole or clindam"cin. LLL Df it#s 44, the best choice is

2actrim.

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Infectious Disease Lecture w/ Dr. Lichtenberger – 3 January 2012The Topic of This Lecture Is: I/ve 0ot a +ever1 and the Only $rescription Is (ore "ow!ell

feer is de&ned as a core bod" temperature of S 4.E° C, though temperature varieswith time of da", anatomic site, ph"sical or emotional activit", and gender (esp. duringovulation).

o Dt is often, but not alwa"s, a sign of infection. lleviation of fever signi&esappropriate therap".

Microorganisms can release e5ogenous yrogens or to'ins (?PIendoto'in, higa to'in,etc).

o ytoines are endogenous p"rogens. @'amples are D?-4, D?-7, TC-*, and DC2-.o  The h"pothalamus receives these signals and causes vasoconstriction, which

conserves heat. Aeat is also retained b" pilo-erection and voluntar" activities.  The bod" produces additional heat b" increasing metabolism and shivering.

Cevers can be treated b" antiyretics, as the" are a response to c"to$ines. The"#re noth"perthermia6

o ;yerthermia is unregulated, e'cessive production of heat. ntip"retics areuseless to treat it.

o  There#s feedbac$ for fevers, so temperature rarel" e'ceeds 48.U° C.  Dn h"perthermia, the temperature freHuentl" e'ceeds 4V.7° C, so the patient

fries to death. single temperature measurement is not clinicall" useful. The acuit" and pattern are wa"

more helpful.o 1haracteristic patterns on a temerature cure can suggest particular diagnoses.

Cevers can be managed with ice pac$s or sponges with cool water. Dce baths are notrecommended.

o /r, use drugs li$e PP, aspirin, Ds, or corticosteroids.o Dt#s probabl" a good idea to let the fever go for a bit to establish a pattern and &ght

infection. <eer of unnown origin (<=>) de&es diagnosis is 8-489 of cases. Dt#s a diagnosis of

e'clusion.o Ph"sical e'ams loo$ at the temperature curve, s$in, mucous membranes, l"mph

nodes, organ si5eR Dnitial labs loo$ at 121, ?CTs, @, ;, blood cultures, and 1>.

o Df still nothing is found, do 1Ts, ultrasounds, MDs, and hell, ma"be even a nuclearmedicine scan.

o  The de&nition of a classical <=> is a temp of S NU° 1 for at least N wee$s with S hospital visits. s$ about travel, contacts, animals, medications, and immuni5ations. Dt could be cancer, infection, inammation, etc. Bust observe6 on#t waste

antibiotics.o  hospitali5ed patient who gets a fever after admission li$el" has a nosocomial

infection or drug fever.

o Patients who are immune-de&cient probabl" have an infection. 'tartantimicrobials &'&4.

o Df a de&nitive diagnosis can#t be reached and the condition is chronic, mortalit"rates are low.  The longer the presence of fever, the less li$el" it#s an infection (higher

chance of cancer). urvival rates are Huite poor if the onl" sign of a neoplasm is a C;/.

Infectious Disease Lecture w/ Dr. Lichtenberger – ? January 2012The Topic of This Lecture Is: Infections "haracteri&ed !y +ever and Lymphadenopathy 

ononucleosis"lie synrome involves fever, fatigue, l"mphadenopath" (esp. in thenec$), and phar"ngitis.

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o  This usuall" a%ects "oung patients. The di%erential includes infections, l"mphoma,and leu$emia.

Infectious mononucleosis is caused b" @2=, but most people infected b" @2= do notdevelop s"mptoms.

o 3ids in da"cares and college-aged fol$s (48-E) are the most li$el" to get thes"mptomatic disease. Dt is probabl" spread b" saliva e'change, not b" fomites. That isn#t hard data.

o  The virus doesn#t have to spread from s"mptomatic patients. Aealth" people shed

the virus.o /ne of the biggest ris$s is slenomegaly, as an enlarged spleen can rupture with

ph"sical activit".o 121s will hopefull" show S 89 mononuclear cells and S 49 at"pical

l"mphoc"tes. @arl" on, there are transient =1-Igs (heterophile). ?ater, permanent DgGs

are developed.•  The test used most commonl" is a rapid agglutination test called

onosot. ?CTs ma" be mildl" elevated, while in cases of 1M=, the" ma" be severel"

elevated.o ntivirals don#t wor$, so Oust treat the s"mptoms and ensure the patient doesn#t

rupture a spleen. ytomegaloirus (@) is the largest virus that can infect humans. Dnfection rates are

prett" high.o ?i$e mono, $ids that go to da"care tend to get it. heltered $ids will get it as

adolescents. Dt can be passed verticall". nd, in D1 patients, proph"la'is is needed to avoid

encephalitis.o erolog" does not reveal heterophiles. The C;/ lasts longer, and a sore throat is

less common.  There#s also less splenomegal", and at"pical l"mphoc"tosis is not e'pected.

o ?i$e mono, we don#t $now how it#s transmitted. Dt can be b" saliva and b" blood

(transfusions).

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rimary ;I@ infection presents however it wants. The most common are those in thislecture#s topic.

o Dn the &rst few wee$s, ;I@ -,& 4- is far, far superior to the @?D serolog" (onl"positive in 89).

o Dn acute retroviral s"ndrome, antiretrovirals is a good idea, but the s"mptoms areself-limited. Dt is possible to notice abnormalities in l"mph tissue on a colonoscop".

7o5olasmosis is caused b" a proto5oon. Aumans are an intermediate host for a parasite

that li$es cats.o  The disease is caused b" touching cat feces (or soil that# s been soiled A A)

and then eating.o /nl" 4-9 of cases are s"mptomatic, producing mono-li$e s"ndrome, at times

with chorioretinitis.o During regnancyA acute to5olasmosis is ba. Dt#s totall" &ne to have it before

pregnanc" (DgG+). Cetuses get intracerebral calci&cations, h"drocephalus, and chorioretinitis.

o iagnosis is b" serolog" in health" patients. Dn D1 patients, to'oplasmosis canreactivate in the brain. D patients that get sei5ures will have ring-enhancing lesions on MD

(biops" con&rms).o /nl" D1 patients (K21 W ) reHuire treatment. ;se sulfaia6ine and

yrimethamine. at"scratch feer is caused b" )artonella henselae. The vector is a ea, but a cat#s

scratch is reHuired.o Dn this disease, there#s a primar" cutaneous papule N-4 da"s after the scratch that

lasts 4-N wee$s. 5ithrom"cin decreases the duration of the l"mphadenopath". arel",

resection is needed.o t"picall", there#s 4arinauBs oculoglanular synrome. Thin$ Xe"e problem +

l"mphadenopath"Y.o ntibiotics don#t reall" help, especiall" in at"pical disease. Prevent it b" $eeping

cats ea-free.

Infectious Disease Lecture w/ Dr. Lichtenberger – ?"C January 2012The Topic of This Lecture Is: Infections "haracteri&ed !y +ever and ,ash

acules are at, non-palpable lesions in the plane of the s$in. Thin$ earl" chic$en po'.o 4aules are palpable and raised. Df the" are large enough, the"#re called noules.o 4ustules are papules that are full of pus. @esicles are small blisters and bullae 

are large blisters. =esiculo-bullous lesions include A=, varicella &oster , and vi!rio vulni2cus (this one is

more bullous). Aumans are the onl" reservoir for ;'@. A=-4 presents in the oral cavit" A=- hangs out

in "our pants.o

D1 patients can have disseminated disease. fever blister might be a precursor to afatal disease.o Dn additional to fever and l"mphadenopath", the rash for A= is grouped vesicles

that are painful.o iagnosis is made b" the 76anc test (smear the opened vesicle), a cultureIP1, or

 Oust a histor".  Treatment is an"thing in the famil" of acycloir. Df it#s severe (li$e, in the

e"es), go D=.  These drugs wor$ b" competing with d-GTP on the viral pol"merase.

Varicella zoster  (@@) onl" a%ects humans. Dt#s spread b" airborne droplets, so itreplicates in the nose.

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o  The &rst infection causes chic$en po', but reactivation for whatever reason causessingles.

o  The disease starts out maculopapular. oon after, vesicles form in a dermatomaldistribution. ;nli$e smallpo', these lesions will be in di%erent stages of healing (mi'ed

presentations).o Df shingles presents in on 1 =4, e"esight can be destro"ed. This necessitates D=

antivirals.

-amsay";unt 'ynrome refers to involvement of 1 =DD, causing 2ell#spals". Vibrio vulnicus is acHuired b" eating raw shell&sh or o"sters, or warm ocean water with

these critters.o Dt prett" much onl" hits patients with underl"ing liver disease (e'cess iron).o "mptoms have abrupt onset of fever accompanied b" h"potension and severe

cellulitis.  There is no diarrhea6 Treat immediatel" with debridement, ciro:o5acin,

and cefta6iime. ,ecroti6ing fasciitis is an immediate emergenc", as both fascia and fat are

progressivel" destro"ed.o  T"pe D is a mi' of aerobic and anaerobic bacteria. Dt happens in D1 patients or after

surger".o  T"pe DD is from S. pyogenes. This can a%ect otherwise health" patients and $ill within

hours.o Dn necroti5ing fasciitis, the lesion is painful (out of proportion), as is the surrounding

area. bulla is Oust the tip of the iceberg. Debriement is absolutely

necessary. Neisseria meningitides can cause bacteremia, causing disseminated intravascular

coagulation (D1).o  The &brin thrombi can then occlude arterioles, leading to infarcts. This is urura

fulminans.  This disease is e'tremel" contagious. 1lose contacts need proph"lactic

antibiotics.o 1ultures reveal Gram- diplococci that ferment maltose and glucose

(meningococcemia). few hemorrhagic pustules at small Ooints can be from isseminate N. gonorrheae.

 Treat with ceftria'one.o ather than getting a culture at the pustule, get it from the source of entr" (mouth

or genitals). Infectie enocaritis from S. viridans or Staph ma" be evidenced b" painless

hemorrhagic macules on the palms or soles ( Janeway lesions) or painful purpuric noduleson the pulp of the digits (>slerBs noes).

Capnocytophaga canimorusus is found in the mouths of dogs. Dt causes severe disease

in asplenic patients.o  There is a disseminated purpuric rash. Treat these patients with 1lavamo'.

S. aureus can cause soft tissue infections, li$e cellulitis. Dt reall" li$es to form pus-&lledabscesses.

o  Treat with 2actrim, clindam"cin, or do'"c"cline. Df it#s M, use vancom"cin. 'econary syhilis involves fever, headache, m"algia, l"mphadenopath", and a

characteristic rash.o  The rash is maculopapular and er"thematous or brown. Dt#s on the palms, soles, and

trun$.o Get a CT on these patients to con&rm the diagnosis. Treat with ben5athine or

penicillin G.

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Eschars are necrotic lesions that grow. Dn $seudomonas, there bacteria invades arteriesand veins.

o  There is ischemic necrosis termed ecthyma gangrenosum. 1ulture and treataccordingl".

utaneous anthra5 is from )acillus anthracis, a Gram+ spore-forming aerobic rod.o Patients contact spores from animals that feed on grass. The ulcer is painful and

edematous.o  Treat this with ciproo'acin or do'"c"cline, unless it#s susceptible to amo'icillin.

D1 patients or diabetics can get mucormycosis in their nasal cavities. Dt ma$es broadh"phae at F°.

Infectious Disease Lecture w/ Dr. Lichtenberger – C January 2012The Topic of This Lecture Is: Travelers/ Diseases

 The most common food-related illnesses are travelers# diarrhea, Aepatitis , t"phoid fever,and giardiasis.

o  Travelers should bring alcohol-based hand saniti5er and use it damn near constantl" /nl" eat freshl" coo$ed food that#s still hot (not a bu%et), or commerciall"

wrapped food.  The" should boil water for S 4 minutes, and the" should avoid ice made

from tap water.

o  The ris$ of food-borne illness is increased simpl" because meals aren#t home-coo$ed.

Most cases of traelersB iarrhea are caused b" Enteroto5igenic E. coli  (E7E),"ielding water" diarrhea.

o  The disease is self-limited to N-E da"s, although in rare cases, there#s post-infectiousirritable bowel. 2lood" stool and more severe diarrhea are associated with E&E and C.

 !e!uni .  Treat with oral reh"dration and a dose or two of uoroHuinolones or

a5ithrom"cin (". 3e3uni).o  The onset ma" be more insidious and associated with gas if it#s a parasite, li$e

giardia or . histolytica.o arel", the cause is rotairus or noroirus (cruise ships6). There will be more

nausea and vomiting.  These viruses are e'tremel" contagious, and outbrea$s are hard to contain.

o "mptomatic treatments are antidiarrheals (bismuth) and antimotilit" agents(loperamide). People who are at high ris$ for infection (D1) can ta$e proph"lactic rifa5imin.

• ?ater, she said that rifa'imin is a good alternative to bismuth. Dt#s Oustmore costl".

;eatitis & is caused b" an ss virus. Dt#s preventable b" vaccine. Dt#s transmitted b"the oral-fecal route.

o  The incubation period is about a month. "mptoms are fever, malaise, anore'ia,

and nausea.  The disease is more severe with increased age, leading to hepatitis (Oaundice

and dar$ pee).o Df travel will begin shortl" after vaccination, hepatitis immunoglobulins are given

instead. 7yhoi feer is caused b" S. typhi. Dt#s seen ever"where but &rst-world countries, e'cept

for travelers.o  The bug can remain in a gallbladder, shedding bacteria chronicall" and a%ecting

close contacts.o "mptoms are high fever (S 4N° C), headache, malaise, anore'ia, splenomegal",

and a faint rash.

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o  The vaccine is not 49 e%ective, but it#s recommended to be given wee$s beforetravel. Df e'posed, diagnosis is made b" culturing the stool, due to bacterial

shedding. Cor Entamoeba histolytica, mature c"sts are ingested, but tropho5oites are what cause

disease.o  The parasites can travel to the lungs or form abscesses in the liver with chocolate-

colored pus.o

 This is a large bowel diarrhea (colitis) J man" small amounts of painful, blood"diarrhea. 1ontrast this to small bowel diarrhea, which is e'plosive, large amounts of

water" diarrhea.o ?i$e most parasites, onset is insidious. 1"sts in stool or positive serolog" appear

before s"mptoms. Df a biops" is done, as$-shaped ulcers will be seen due to inasie

amoebiasis.o Df there#s no invasion, treat the diarrhea with paramom"cin. Df it#s invasive, use

metronida5ole. 4aramomycin is an aminogl"coside that is not absorbed from the GD tract

(lumenal).

"iardia is a proto5oon that is not invasive. The tropho5oites Oust attach to the duodenum.o s a small bowel issue, there are foul-smelling, greas" stools with a lot of atulence

and cramps.o iagnosis is made b" an @?D test on the stool. Treat this parasite with

metronida5ole.

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&rthroo"relate infections include those from mosHuitoes, sandies (?eishmaniasis),tic$s, and eas.

o Minimi5e ris$ b" wearing proper attire, inspecting for tic$s, and avoiding activit"from dus$ to dawn. epellants li$e @@T help, as do bed nets or clothes that have been treated

with permethrin. Dn an" patient that has come from an endemic area and has a C@=@, suspect malaria as

a cause.o

/nl" a few areas in the world have malaria that can be treated b" chlorouine (Aaiti is one of them).o isease is caused b" sporo5oites that mature in the liver and leave as mero5oites.

 The" mature in 21s, which eventuall" l"se (anemia6) and releasegametocytes.

o  The mosHuitoes that carr" the disease are #nopheles, which are nocturnal (that#simportant).  The &rst s"mptoms are C@=@, headache, and malaise. ?ater, there#s

hemol"tic anemia.o  The $lasmodium species that $ills people is P. falciparum. /thers are $. viva4  and

$. ovale.  The latter patients reHuire rimauine to treat the liver h"pno5oites.

o 1hemoproph"la'is is onl" given to travelers whose itinerar" puts them at ris$. Df chloroHuine can be given, it#s a wee$l" drug given 4- wee$s before to E

wee$s after. Df not, tr" me:ouine, but it has some prett" awful ps"chiatric side e%ects.

• rugs that must be ta$en dail" include atoauone (Malarone) ando5ycycline.

Dengue feer is transmitted b" *edes aegypti, which is a diurnal mosHuito that lovesstagnant water.

o  There are four serot"pes. n initial infection "ields immunit" for one but not theothers. 2ut, a second infection b" another serot"pe increases ris$ for hemorrhagic

feer (D;<).o Dnitial s"mptoms are fever, retro-orbital headache, m"algia, and a rash on da"s N-8.o Dn cases of AC, there are lea$" capillaries and thromboc"topenia, necessitating

medical care. n"one with a diagnosis of dengue fever should avoid aspirin for this reason.

 The same mosHuito for dengue caries yellow feer, transmitted b" a avivirus for whichwe have a vaccine.

o @arl" s"mptoms are u-li$e, but a to'ic phase follows with liver failure andhematemesis.

o  The vaccine for "ellow fever has a chance of inducing neurotropic disease. Thatsuc$s.

$ic%ettsiae africae is carried b" tic$s. Dt#s an intracellular pathogen that hangs out in

sub-aharan frica.o Most patients will develop a fever, rash, and ma"be other benign s"mptoms. Treat

with do'"c"cline.

&eptospirosis is caused b" a spirochete that hangs out in water that infected animalspiss in.

o Cirst, there are u-li$e s"mptoms, followed b" liver damage. ?CTs are ver" high, but total bilirubin onl" mildl" elevated.

o  The spirochetes can be identi&ed b" serolog" or DG uoroscop". Treat withdo'"c"cline.

'yhilis is caused b" Treponema pallidum. Dt can imitate man" diseases due in its laterstages.

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o  The initial presentation chancre is a painless chancre, seen on whatever touched avagina.  The secondar" stage is conylomata lata (rash), along with s"stemic signs.  The tertiar" stage is rg"ll-obertson pupil, neuros"philis (ata'ia), and

whatever else.o @D-L is a non-speci&c test. 1on&rm the diagnosis with <7& (both positive means an

active infection). Df the =? is + but CT is -, it#s a false positive. Df onl" CT is +, it#s been

treated.o gain, the &rst-line treatment for s"philis is an inOection of penicillin G.

 These are spirochetes, so don#t get these mi'ed up with the arthropod-mediated diseases.

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Infectious Disease Lecture w/ Dr. Lichtenberger – C January 2012The Topic of This Lecture Is: 0eographic Diseases of the 5.S. of *

-ocy ountain sotte feer is caused b" ,ic-ettsia ric-ettsii. Dt is /T found instates near the oc$ies.

o special stain is needed to identif" this intracellular pathogen indigenous to the&tlantic coast (1).  The tic$ has to be attached for several hours before ,. ric-ettsii is

transmitted.o Dnitial s"mptoms are u-li$e, but later there#s abdominal pain with arthralgia.

ash starts after fever. Dt#s petechial, with small, at, pin$, non-itch" maculeson distal Ooints.

• evere s"mptoms of MC are pneumonitis and vasculitis. iagnosis is b" s"mptoms and the epidemiological clues (near tall grass,

woods, etc).o /n serolog", DgM titers appear &rst, then DgG antibodies after wee$s (li$e

ever"thing else).  The antibod" assa" is for Feil"<eli5. ?earn that name. Treat this with

do'"c"cline. Ehrlichia cha'eensis is a small Gram- bacteria that clusters inside of macrophages.

o Dt#s carried b" the Lone"star tic  or dog tic$, which hang out in Te'as and the

outheast ;..o s opposed to MC, the rash is maculopapular, and it#s also less li$el" to be seen.

=asculitis is rare. iagnosis is made b" elevated DgG and a blood smear for the pathogen (or

P1).o 1ontrast this bug with #naplasma phagocytophilim, which is from I4odes in the

ortheast ;.. lso, *. phagocytophilim invades granuloc"tes li$e PMs rather than

macrophages. Lyme isease is caused b" the spirochete )orrelia !urgdorferi, via the tic$ ()odes

scapularis.o  The most prominent epidemiological sites are Minnesota, Kisconsin, and the

ortheast ;..  The disease is transmitted b" n"mph-stage tic$s that feed for E-N7 hours.

o  The pathognomonic sign is the bullBs"eye rash, which has the fanc" nameerythema migrans. @arl" ?"me titers are probabl" negative, so Oust diagnose via the clinical

picture.o ?ater signs are fever, = nodal bloc$, mononeuritis, hepatitis, ophthalmitis, and

arthritis.  The arthritis is seen in stage N (persistent), along with encephalopath" or

pol"neuropath".o  The cornerstone of treatment is do'"c"cline. ?ater-staged disease reHuires

ceftria'one too. nother disease carried b" I4odes is Babesia microtii , which forms a Maltese cross within

cells.o Dt#s not a huge deal e'cept in patients without spleens. Dt presents a lot li$e malaria.

 There#s fever, chills, headache, m"algia, anemia, etc. 2ut, there#s no histor"of travel.

Patients without spleens will die from cardiorespirator" failure or renal failure.o  This is the onl" tic$-related disease not treated with do'"c"cline6 Dnstead, treat it

li$e malaria. Go with atoauone and a6ithromycin. Give blood transfusions for severe

anemia.

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 The three enemic mycoses are dimorphic, in that the" are molds in nature but "east intissue.

o  The clues for diagnosis are the geographic distribution and the smear.o  The" all cause progressive fever, d"spnea, and cough with oral ulcers and

organomegal". *istoplasma capsulatum is found in the Mississippi iver =alle". Thin$ bats, cave

e'ploration, and Tennessee.o putum cultures are rarel" positive. The" loo$ li$e little suns or li$e &sh eggs.

Df in the lungs, antigens are obtained on lavage. Df disseminated, antigens arein the urine.o Df the disease is progressive or chronic, use itracona6ole. Dn D1 patients, use

amphotericin 2. Blastomyces dermatitidis also li$es the M=. Dt prefers the lungs, but has the potential

to infect bones.o 1ultures of s$in lesions and biops" are much better than serolog".o s opposed to histoplasmosis and coccidiom"cosis, treat E@E->,E, not Oust

complicated cases. Cor Coccidiodies immitis, it#s found in the soil of the outhwestern deserts and an

 BoaHuin iver =alle".o issemination is rare in an immunocompetent host. Pulmonar" s"mptoms are Oust

u-li$e.o  The mainsta" of diagnosis is serolog" (or biops"), not blood culture. There is

eosinohilia6o Dn most cases, Oust observe. 2ut, pregnant or D1 patients reHuire ucona5ole.

4aracocciiomycosis presents the same wa", but it#s found in 2ra5il and outh merica.o Dt can cause chronic pulmonar" s"mptoms. iagnose b" biops" of a bug that loo$s

li$e a ship#s wheel.

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Infectious Disease Lecture w/ Dr. Lichtenberger – C January 2012The Topic of This Lecture Is: 6oonoses

gain, at"scratch feer is caused b" )artonella henselae. 1ats are bacteremic butas"mptomatic.

4lague is caused b" 7ersinia pestis, transmitted b" a ea bite from those that live onprairie dogs, rats, etc.

o bubonic lymh noe is painful and e'tremel" swollen, locali5ed near the bite.o 4ulmonic lague is a rapid pneumonia that can spread through blood or an

aerosol (dear God). Dt can cause septicemia and necrosis of distal e'tremities. Treat with

aminogl"cosides. Brucella is found in man" animals, but we care about livestoc$, since it#s transmitted in

unpasteuri5ed dair".o Dt#s a widespread 5oonosis mediated b" a Gram- intracellular bacteria. on#t eat

fanc" Crench cheese.o  There#s an insidious onset of fatigue, weight loss, anore'ia. Patients Oust feel unwell

for months.  There ma" be sacroiliitis, epidid"mitis, orchitis, and so on. Dt involves man"

organs.o iagnosis reHuires a histor" of consuming unpasteuri5ed dair". erologic testing

con&rms. Monotherap" doesn#t wor$ often, so we go with a tag-team of do'"c"cline

and gentamicin. +rancisella tularensis is a Gram- intracellular bug that causes tularemia. Dt#s carried b"

bunnies and sHuirrels.o  The animals get it from tic$s. Ke get it being near infected rabbits or eating poorl"

coo$ed bunn".  The epidemiological areas for the boards are Missouri, r$ansas, and

Martha#s =ine"ard.o i' forms< ulceroglandular, glandular, oculoglandular, orophar"ngeal, t"phoidal,

pulmonar".o  Tularemia can be obtained b" aerosol, so be careful when culturing it for diagnosis

(P1 wor$s too). Df the lungs are a%ected, mortalit" rates are high. Treatment is alwa"s b"

aminogl"cosides. ,. ric-etsii causes MC (tic$s), $. typhi  is from eas, $. pro+aze%ii  is from lice. ll are

Feil"<eli5 ositie.o Khile MC has a petechial rash that a%ects palms and soles (Ooints6), the other two

do not. lso note that enemic tyhus causes a more maculopapular rash (esp. on

the bac$).o ll of these are treated b" do'"c"cline. ote that onl" ,. prowa&e-ii is not endemic

(it#s epidemic).

Co)iella burnetii  is transmitted b" aerosol. Dt does not cause a rash rather, it causes #feer.o iagnosis is b" serolog" and a histor" of being near pregnant livestoc$ or pets.o Dt#s part of the wor$up for C;/, although there ma" also be headache and

pneumonia. *antavirus is transmitted b" aerosols from dried rat feces from a chronicall" infected rat.

o Dt presents with severe pneumonia along with fever, m"algia, and cough.o iagnose it b" DgM serolog" or P1. ince it#s a virus, there#s no treatment but

support. Lymhocytic choriomeningitis (L) is an ss virus transmitted b" rats. 1lose

contact is reHuired.

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o D1 patients (transplant recipients) are at ris$ too. Dt#s from inhaling e'creta or beingscratched.

o  The u-li$e s"mptoms subside after -E da"s, then come bac$ (hopefull" not asencephalitis).

Fest ,ile @irus is a J virus transmitted b" mosHuitoes. Df it gets into birds, the birdsdie rapidl".

o Aumans and other animals are incidental hosts. lmost ever"one is &ne within awee$.

o

2ut, W 49 of fol$s get meningoencehalitis , fever, ata'ia, and muscle wea$ness(accid paral"sis).o iagnosis is b" DgM in the serum or 1C. ote that P1 is not helpful.

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Infectious Disease Lecture w/ Dr. Lichtenberger – C January 2012The Topic of This Lecture Is: Infectious Diarrheal Illnesses

 The incubation period for norovirus is about EU hours. =omiting and diarrhea persist forabout da"s as well.

o $otavirus also causes viral enteritis. Prett" much ever" $id will get it b" the timethe"#re 8 "ears old.

Cor food-borne diseases, incubation periods provide clues to diagnosis. Df it#s W hours, it#sa chemical agent.

o Df it#s -V hours, it#s a preformed to'in (li$e S. aureus). Df it#s U-4E hours, it#sClostridium pernges. n"thing more than 4E hours is a viral or bacterial pathogen doing its thing.

o o not give antibiotics for S. aureus foo oisoning6 lso, the $e"word isXma"onnaiseY.

o Cor ". per2nges, there#s water" diarrhea and no vomiting. The $e"word is XreheatedmeatY.

o Cor Bacillus cereus, there#s an emetic form with a short incubation and an entericform that#s longer.  The $e"word for ). cereus mediated food poisoning is Xfried riceY.

on-invasive diarrhea is caused b" @T@1 or @@1. This is traelersB iarrhea orpersistent diarrhea in $ids.

o  Treat this with 2actrim or uoroHuinolones, and it#ll resolve without seHuelae. Dnvasive diarrhea is ysentery. There#s fever, abdominal pain, and blood" diarrhea with

mucus. Enterohemorrhagic E. coli  (E;E) secretes a to'in li$e higella. Dt contaminates leaf"

green veggies.o Dt also a%ects undercoo$ed meats. tin" amount of bacteria can cause s"mptoms.

 There#s no fever.o  There is hemorrhagic colitis without fever, but there#s a ris$ for hemolytic uremic

synrome. A; is evidenced b" hemol"tic anemia, renal failure (high 1r), and

thromboc"topenia.o o /T give antibiotics or antimotilit" agents because this is mediated onl" b" a

to'in6 Shigella is similar, but it also causes a fever. Dt 1 be cured b" antibiotics< CQ, 2actrim,

and ceftria'one. ,on"tyhoi Salmonella infects poultr" (eggs6). Dt induces blood" diarrhea and can

cause bacteremia.o s opposed to Shigella, it has a high inoculum, and it is motile. 2oth of them are

lactose fermenters. Campylobacter !e!uni  causes the same s"mptoms. Dt can be cultured at higher

temperatures (E° 1).o o, s"mptoms are usuall" not enough to di%erentiate causes of invasive diarrhea.

Get a culture.o

 Treat ". 3e3uni with a5ithrom"cin. 1omplications include G2 or reactive arthritis. Clostridium dicile is an anaerobic Gram+ bug that forms spores and produces a to'in.o Dt is the usual cause of antibiotic"associate iarrhea. Dt#s diagnosed b" seeing

to'in in the stool. 2ecause it ma$es spores, it#s hard to $ill. This is wh" it spreads in hospitals.

o 4seuomembrane colitis can worsen into 7>8I EG&>L>, with certainstrains of ". dicile. ot ever"one with 1 presents with diarrhea. Most don#t have fever, Oust

leu$oc"tosis. Dmaging ma" show dilation of the colon. Df it gets to S 4 cm, hol" shit cut out

the colon.

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o  Treatment is metronida5ole is if it#s mild or /? vancom"cin if it#s severe (ma"bewith D=DG). n odd treatment that actuall" wor$s ver" well is a fecal transplant.

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Infectious Disease Lecture w/ Dr. Lichtenberger – H January 2012The Topic of This Lecture Is: ,espiratory 8iral Infections: In%uen&a

In:uen6a & infects oodles of animals and humans, so it causes epidemics andpandemics.

o Dnuen5a 2 onl" infects people and parrots. Dnuen5a 1 onl" infects humans andswine.

o  The antigen gl"coproteins in inuen5a are hemagglutinin and neuraminiase (AZZ). Kithin the viral capsid, there are multiple segments. The" are able to

mutate.o  The viruses that can infect humans are A4-AN and 4-, but dramatic drifts are

possible and deadl". Dt#s na[ve viruses that cause maOor issues, as people develop antigens if

the"#re e'posed. Dnuen5a tends to start in wild aHuatic birds, then gets to poultr", then pigs

or people.o Pandemics tend to occur when an avian virus undergoes genetic reassortment with

a human virus.  The most important s"mptom of inuen5a is a ery high feer, plus chills, bone pain,

m"algia, and nausea.

o Dnfants, old people, and pregnant chic$s can end up with pneumonia, m"ocarditis,or encephalitis.o Khen a patient with inuen5a is in the hospital, an F8 mas$ is not needed, Oust a

regular one. Dt is spread b" droplets that do not remain as an aerosol. The virus hangs out

on surfaces.o rai antigen test is obtained b" Oamming a swab into the nasophar"n' (not the

mouth). Khile the test is prett" speci&c, it is not sensitive. Preferabl", Oust use the

clinical picture. /ne should test hospitali5ed patients, pregnant women, and cases outside of

outbrea$s.

7ami:u is onl" given if the u is caught within the &rst EU hours. /therwise, Oust providesupportive uids.

o  The e'ception to this rule is pregnant women. Dn clinical practice, the" get meds nomatter what. /thers include $ids under 8, people over 78, and those with chronic medical

conditions.o >seltamiir (Tamiu) and 6anamiir are neuraminidase inhibitors that prevent

release of virions.o Df there are pulmonar" s"mptoms, treat the patients for 1P, which ma" be from

secondar" bacteria. Dnuen5a can be prevented b" vaccination and freHuent hand-washing. lso, snee5e into

"our damn elbow.o on#t touch "our mucous membranes after touching other stu%. ta" home if "ou#re

sic$.

Infectious Disease Lecture w/ Dr. Lichtenberger – H January 2012The Topic of This Lecture Is: HI8 and $rimary "are

ntigenicit" to AD= is mediated b" the surface gl"coprotein g120, along with gpE4.o AD= li$es to infect 1E T-cells, macrophages, and dendritic cells. Dt binds to the host

at -C. People who are homo5"gous for a 118 variant are immune to AD=.

o fter binding, is inOected into the cell. Dt#s reverse transcribed to , thenintegrated.

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/nce integrase does its thing, new viral and AD= proteins can betranscribed.

o  The turnover of the virus is unbelievabl" fast. /ver 44 virions are produced anddestro"ed dail".

o everse transcriptase is a prett" awful en5"me, but its mista$es provideheterogeneit" for the virus.

Dn dudes, the incidence of AD= from heterose'ual contact is increasing toward that of ga"men.

o

Cor women, the second most li$el" cause of AD= other than se' is D= drug abuse.o 2ut, on a case b" case basis, the highest ris$ is from needle-sharing or receiving

buttse'. Dmmediatel" after e'posure, there#s an e'tremel" high viral load. Dt then drops to a

relativel" stable set point.o imilarl", the T-cell count drops acutel", then returns to baseline. Dt then steadil"

declines.o &ID' is de&ned as a 1E count below . t that point, viral load starts increasing

sharpl". t a 1E count below 8, there#s increased ris$ of infections and neoplastic

events. Df 1E drops below 8, then patients can get stu% li$e 1M=, MD, or

l"mphoma.  The other de&nition of D is the presence of an opportunistic infection.

o  The most common pneumonia in D patients is still S. pneumoniae, even thoughthe" can get P1P.

 The normal test for AD= is ELI'&, con&rmed b" Festern blot, since there#s a ris$ of falsepositives.

o 2ecause of false positives, never report @?D as positive6 Dt is termed XreactieY orXnon-reactiveY. Df there is a reactive @?D, the &rst step is to repeat it. Then, do a Kestern

blot. Calse negatives can be due to a winow erio (\ wee$s), recent

transfusion, or transplant.o positive Kestern blot is an" of pE, gpE4, or gp47I4. egative ] no bands,else indeterminate. Dndeterminate tests can be interpreted with regard to iral loa (positive if S

4). Kestern blots will be negative at later evaluation if antiretrovirals are started

earl".o  The other test is for the AD= viral load, which is the nucleic antigen test (,&7

;@"1). lwa"s get informed consent before an AD= test and onl" disclose results in person.

o Go over the last three slides, since it#s stu% that needs to be regurgitated on thee'am.