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MIKROBA PENYEBABINFEKSI SISTEM SARAF
Riyani WikaningrumBag. Mikrobiologi Fak. Kedokteran
Univ. YARSI
Infeksi Mikroba pd SSP
• Diawali dengan kolonisasi mukosa (saluran nafas atas atau gastrointestinal) menyebar melalui peredaran darah, menembus blood brain barrier dan menyebar ke cairan serebrospinal
• Invasi ke SSP melalui saraf perifer bisa terjadi (retrograd) misal pada gol virus Herpes dan virus rabies
• Invasi lokal (perkontinyuitatum); misal dari sinus
Mikroba menembus BBB
• Mikroba menginfeksi sel penyusun sawar otak • Mikroba ditransport melalui vakuol
intraseluler sel penyusun sawar otak• Mikroba dibawa oleh sel lekosit yang terinfesi
Penyebab infeksi SSP
• Bakteri:– H. influenzae– N. meningitidis– S. pneumoniae– E. coli– S. aureus– Listeria monocytogenes– Mycobacterium tuberculosis– Treponema pallidum
Penyebab infeksi SSP
• Fungi:– Cryptococcus neoformans
• Virus:– Herpes simplex virus - JC virus– Mumps virus - Arbovirus– Coxsackievirus - Rabies virus– Echovirus - Measles virus – Rubellavirus - Prion– Poliovirus– HIV
LCS
Cells/ml Protein (mg/dl)Glucose (mg/dl) Causes
Normal 0-5 15-45 45-85 -
Septic (purulent) meningitis
200-20000 (mainly neutrophils)
High (>100) <45 Bacteria, amebae, brain abscess
Aseptica meningitis or meningoencephalitis
100-1000 (mainly mononuclear)
Moderately high (50-100)
Normalb Viruses, tuberculosis, leptospira, fungi, brain abscess, partly treated bacterial meningitis
aAseptic because the CSF is sterile on regular bacteriologic culture.bLow (<45) in the case of tuberculosis, fungi, leptospira.
Bacterial MeningitisPathogen Treatmenta Prevention
Neisseria meningitidis Penicillin (or chloramphenicol)
Rifampicin prophylaxis for close contacts; polysaccharide vaccine (poor protection against group B)
Haemophilus influenzae Ampicillinb, ceftriaxone or cefotaxime (or chloramphenicol)
Polysaccharide vaccine against type b (Hib)
Streptococcus pneumoniae
Penicillinc (or ceftriaxone or chloramphenicol)
Prompt treatment of otitis media and respiratory infections; polyvalent (23 serotypes) polysaccharide vaccine
Bacterial MeningitisPathogen Treatmenta Prevention
Escherichia coli (and other coliforms), group B streptococci
Gentamicin + cefotaxime or ceftriaxone (or chloramphenicol)b
No vaccines available
Listeria monocytogenes Penicillin or ampicillin + gentamicin
No vaccines available
Mycobacterium tuberculosis
Isoniazid and rifampin and pyrazinamide ± streptomycin
BCG vaccination; isoniazid prophylaxis for contacts recommended in USA
Bacterial Virulence Factors
Virulence factor Bacterial pathogenNeisseria meningitidis
Haemophilus influenzae
Streptococcus pneumoniae
Capsule + + +IgA protease + + +Pili + + -Endotoxin + + -Outer membrane proteins
+ +
Polysaccharide capsules are important virulence factors in the pathogenesis of bacterial meningitis
Pathogen Capsule Important type Vaccine
Neisseria meningitidis
Polysaccharide A, B, C, Y, W-135 Good for A and C; poor for B
Haemophilus influenzae
Polysaccharide B Hib vaccine for <1 year olds
Streptococcus pneumoniae
Polysaccharide Many Pneumovax: 23-valent most common types
Group B streptococcus
Polysaccharide rich in sialic acid
(Ia, Ib, II) III in neonatal meningitis
- ? Future
Escherichia coli KI in meningitis - ? Future
Neisseria meningitidis
Meningokokus
13
upper respiratory tractupper respiratory tract infection infection – adhesion pili adhesion pili
bloodstreambloodstream
brainbrain
NeisseriaNeisseria meningitidismeningitidis
14
• second most common meningitis second most common meningitis – pneumococcus, most common pneumococcus, most common
• fatal if untreated fatal if untreated
• responds well to antibiotic therapyresponds well to antibiotic therapy– penicillin penicillin
Meningococcal meninigitisMeningococcal meninigitis
15
Laboratory DiagnosisLaboratory Diagnosis
• spinal fluid spinal fluid – Gram negative diplococci Gram negative diplococci
within polymorphonuclear cellswithin polymorphonuclear cells– meningococcal antigens meningococcal antigens
• CultureCulture– Thayer Martin agar Thayer Martin agar
16
• capsulecapsule inhibit phagocytosis inhibit phagocytosis• anti-capsular antibodiesanti-capsular antibodies stopstop infectioninfection•antigenic variationantigenic variation sero-groupssero-groups• vaccine vaccine multiple sero-groups multiple sero-groups
CapsuleCapsule
• Bakteri berbentuk batang kecil, pleomorfik, Gram (-), membutuhkan faktor pertumbuhan khusus untuk isolasinya
• Faktor pertumbuhan darah atau derivatnya• Spesies penting:
– H. influenzae– H. aegyptius– H. ducreyi– H. parainfluenzae; H. aphrophilus; H. paraaphrophilus
H. Influenzae (Gram)
H. influenzae• Parasit pada manusia yang berkapsul
menyebabkan:– Meningitis, epiglotitis, pneumonia, aryhritis,
bronchitis, otitis media
• Bakteri yang tidak berkapsul dapat sebagai flora normal faring 25 – 80% populasi normal
• Morfologi bakteri – dari sampel akut basil coccoid, berpasangan
/ rantai pendek– Dari biakan tua pleomorfik– Mempunyai kapsul reaksi Quellung untuk
penentuan serotipe
• Biakan:– media BHI agar dan Agar coklat– Inkubasi 36 – 48 jam– Satelite phenomenon koloni tumbuh > di
sekitar koloni S. aureus (kuman lain)
• Faktor pertumbuhan:– Faktor X Hemin– Faktor V NAD / co-enzim lain
• Struktur Antigen:– Ag kapsul polisakharida dibedakan
menjadi tipe a, b, c, d, e, f.• Tipe b PRP (Polyribose-ribitol phoaphate)• Penentuan dengan reaksi Quellung atau
immunofluoresensi
– Ag somatik protein membran luar– LPS (endotoksin) ~ Neisseria
Satelite phenomenon
Pertumbuhan H. influenzae dg faktor X dan V
Berdasarkan kebutuhan faktor X dan V
Spesies Faktor X Faktor V Hemolisa
H. Influenzae
H. aegyptius
+ +
H. Parainfluenzae +
H. Ducreyi +
H. Haemolyticus + + +
H. parahaemolyticus + +
H. aphrophilus
Diagnosis Laboratorium• Bahan pemeriksaan:
– Usap tenggorok, pus, darah, LCS
• Pemeriksaan langsung:– Immunofluoresensi– Quellung
• Kultur:– Agar coklat + IsoVitaleX– Identifikasi dengan melihat kebutuhan faktor X dan V
Kekebalan• Bayi umur < 3 bulan mempunyai kekebalan
dari Ibu• Anak umur 5 bulan – 5 tahun rentan terhadap
infeksi H. influenzae meningitis• Diberikan vaksinasi vaksin Hib pada anak
Terapi• Angka mortalitas meningitis 90%• Kebanyakan H. influenzae tipe B sensitif
penisilin; tetapi 25% telah resisten• Antibiotik lain: Kloramfenikol, sefalosporin
generasi baru
Streptococcus pneumoniae
Streptococcus pneumoniae
30
S. pneumoniae • leading cause of pneumonialeading cause of pneumonia
– particularly young and oldparticularly young and old– after damage to upper respiratory tractafter damage to upper respiratory tract
**e.g. following viral infectione.g. following viral infection• bacteremiabacteremia• meningitismeningitis• middle ear infections (otitis media)middle ear infections (otitis media)
31
S. pneumoniae
• α hemolytic hemolytic• pneumolysin pneumolysin
– degrades red blood cells under aerobic conditions degrades red blood cells under aerobic conditions
• grows well on sheep blood agargrows well on sheep blood agar• no group antigen no group antigen
32
Diagnosis - spinal fluidDiagnosis - spinal fluid
• direct Gram stainingdirect Gram staining• detection of capsular antigendetection of capsular antigen
33
Not optochin sensitive
optochin sensitive
IdentificationIdentification
34
CapsuleCapsule
• prominent prominent – virulent strains virulent strains
• anti-phagocyticanti-phagocytic• carbohydrate antigens carbohydrate antigens
– vary among strainsvary among strains
35
CapsuleCapsule
• immunity immunity – serotype specificserotype specific
• vaccine contains multiple serotypesvaccine contains multiple serotypes• only for susceptible populationonly for susceptible population
36
Quellung reactionQuellung reaction
• using antisera using antisera • capsule "fixed" capsule "fixed" • visible microscopicallyvisible microscopically
37
PathogenesisPathogenesis
• Teichoic acidTeichoic acid–complement activation complement activation – large numbers of inflammatory cells large numbers of inflammatory cells at infection siteat infection site
38
TherapyTherapy
• S. pneumoniaeS. pneumoniae – most strains susceptible to penicillin most strains susceptible to penicillin – resistance is commonresistance is common
39
Streptococcus in chains (Gram stain)
40
groupable streptococci streptococci • A, B and DA, B and D
– frequentfrequent
• C, G, F C, G, F – less frequentless frequent
41
Group B streptococcusGroup B streptococcus
• neonatal meningitisneonatal meningitis• septicemiasepticemia• transmission transmission
– vaginal floravaginal flora
42
Group B streptococcus Group B streptococcus - identification- identification
• β hemolysishemolysis• hippurate hydrolysishippurate hydrolysis• CAMP reactionCAMP reaction
– increases increases β hemolysis of hemolysis of S. aureusS. aureus
43
Mycobacterium tuberculosisMycobacterium tuberculosis
obligate aerobeobligate aerobeacid-fast rodsacid-fast rods
Mycobacterium tuberculosisZN staining
45
• M. tuberculosisM. tuberculosis• major human diseasemajor human disease
– healthy peoplehealthy people • problems problems
– association with AIDSassociation with AIDS– multiple drug-resistancemultiple drug-resistance
Tuberculosis Tuberculosis (TB, consumption)(TB, consumption)
46
Transmission -tuberculosisTransmission -tuberculosis
• M. tuberculosis M. tuberculosis causes diseasecauses disease–healthy individuals healthy individuals
• transmitted man-man transmitted man-man • airborne dropletsairborne droplets
47
Pathogenesis of tuberculosisPathogenesis of tuberculosis
• infects lunginfects lung
• distributed within macrophagesdistributed within macrophages
• facultative intracellular pathogenfacultative intracellular pathogen– inhibits phagosome-lysosome fusioninhibits phagosome-lysosome fusion
48
Cell-mediated immunity -tuberculosisCell-mediated immunity -tuberculosis
• infiltration infiltration – macrophages macrophages – lymphocyteslymphocytes
• granulomasgranulomas• tuberculestubercules
Miliary TB Meningitis TB
50
Laboratory diagnosis - Laboratory diagnosis - tuberculosistuberculosis
• skin testingskin testing– delayed hypersensitivity delayed hypersensitivity – tuberculin tuberculin – protein purified derivative, PPDprotein purified derivative, PPD
• X-rayX-ray
51
Positive skin test -tuberculosisPositive skin test -tuberculosis
• indicates exposure to organismindicates exposure to organism• does not indicate active diseasedoes not indicate active disease
52
Other minor pathogenesis factors Other minor pathogenesis factors tuberculosistuberculosis
• mycobactin mycobactin – siderophoresiderophore
• cord factor cord factor – damages mitochondriadamages mitochondria
53
Laboratory diagnosis Laboratory diagnosis M. tuberculosisM. tuberculosis
• acid fast bacteria acid fast bacteria – sputum sputum
54
Laboratory diagnosis Laboratory diagnosis M. tuberculosis M. tuberculosis (culture)(culture)
• grows very slowlygrows very slowly– two weeks or longertwo weeks or longer– non-pigmented coloniesnon-pigmented colonies– niacin productionniacin production
*differentiates from other mycobacteriadifferentiates from other mycobacteria
55
TuberculosisTuberculosis• polymerase chain amplificationpolymerase chain amplification
– rapid diagnosisrapid diagnosis
56
Antibotic treatment - tuberculosisAntibotic treatment - tuberculosis
• extensive time periods (e.g. 9 months)extensive time periods (e.g. 9 months)• organism grows slowly, or dormantorganism grows slowly, or dormant• two or more antibioticstwo or more antibiotics
– e.g. rifampin and isoniazide.g. rifampin and isoniazid– resistance minimizedresistance minimized
57
Tuberculosis and Drug resistance
• Multiple drug resistant (MDR)– resistant to first line drugs
• Extremely drug resistant (XDR) –Resistant to some of the second line drugs–Nearly un-treatable
58
VaccinationVaccination
• BCG vaccine BCG vaccine – an attenuated strain of an attenuated strain of M. bovisM. bovis – not effectivenot effective
• in US, in US, – incidence is lowincidence is low– vaccination not practicedvaccination not practiced– immunization interferes with diagnosisimmunization interferes with diagnosis
59
Clostridium tetani
sporespore
vegetativevegetative
Clostridium
• sifat-sifat umum:– Batang (+) gram, memiliki spora (>besar dari badan
vegetatif), berflagel– bersifat anaerob– alamiah ditemukan di alam bebas dan pd saluran cerna
hewan dan manusia
• Dapat digolongkan atas:– histotoxic Clostridia (sangat invasif)– tissue infections (wound infections)– neurotoxic Clostridia (tidak invasif)
61
Clostridium tetaniClostridium tetani
• Non-invasiveNon-invasive
Clostridium tetani
• Banyak ditemukan di alam bebas• Tumbuh pada jaringan mati, Eh +10mV• Menghasilkan toksin tetanoplasmin
menjalar sepanjang saraf ke SSP dan terikat pada sel ganglion kontraksi otot
• Kematian umumnya karena tidak bisa bernafas
• Pencegahan dengan vaksin Toxoid Tetanus
63
TetanospasminTetanospasmin
• disseminates systemically disseminates systemically • binds to ganglioside receptors binds to ganglioside receptors
– inhibitory neurones in CNSinhibitory neurones in CNS• muscles keep on workingmuscles keep on working• spastic (rigid) paralysisspastic (rigid) paralysis• glycine glycine
– neurotransmitterneurotransmitter
64
A severe case of tetanus. A severe case of tetanus. muscles, back and legs are rigid muscles, back and legs are rigid muscle spasms can break bonesmuscle spasms can break bones can be fatalcan be fatal (e.g respiratory failure)(e.g respiratory failure)
65
• infantinfant• DPT (diptheria, pertussis, tetanus)DPT (diptheria, pertussis, tetanus)• tetanus extremely uncommon in UStetanus extremely uncommon in US• tetanus toxoid tetanus toxoid
– antigenicantigenic– no exotoxic activityno exotoxic activity
VaccinationVaccination
66
C. botulinumC. botulinum
Clostridium botulinum• Terdapat di alam bebas, dapat mengkontaminasi makanan
(kaleng)• Penyebab botulisme• Menghasilkan toksin (neurotoxin) yang sensitif terhadap
panas• Toxin bekerja pada sistem saraf perifer menghambat
pelepasan asetilkholin pada sinaps saraf paralisis otot• Gejala berupa disfagia, mulut kering, diplopia, kesulitan
bernafas• Terapi dengan antitoxin guna menetralisir toxin yang belum
terikat pada sel target• Botulisme pada bayi disebabkan bayi menelan spora
bakteri. Dikaitkan dengan madu yang terkontaminasi spora.
Food poisoning – C. botulinum
• Eksotoksin menyebabkan botulisme• Menghasilkan 7 macam eksotoksin, yang
menyebabkan penyakit pada manusia adalah A, B, E dan F.
• Tahan terhadap enzim pencernaan• Rusak pada pemanasan 80 derajat C, 30 min• Makanan yang dikaitkan:
– Makanan awetan dalam kaleng– Makanan yang terkontaminasi spora bakteri
Botulisme
• Macam:– Food-borne botulism– Infant botulism– Wound botulism
• Gejala berupa flaccid paralysis (penglihatan ganda, kesulitan bernafas) timbul sesudah 12 – 36 jam sesudah ingesti makanan.
• Berlangsung 2 – 6 hari dan dapat fatal
75
• anti-toxin anti-toxin • antibiotic therapy (if infection)antibiotic therapy (if infection)
TreatmentTreatment
Listeriosis
• Sumber penularan adalah makanan: susu, keju, sayuran (dipupuk dengan kotoran ternak)
• Gol yang rentan adalah wanita hamil; lansia dan pasien yg daya kekebalannya rendah.
• Gejalanya bisa ringan sampai berat.• Penyimpanan makanan dalam suhu dingin
tidak menghambat pertumbuhan bakterinya.
Listeria monocytogenes
• Listeria patogen unutk manusia dan hewan• Morfologi: batang, Gram (+), gerak (+)• Kultur: agar Mueller-Hinton; fakultatif
anaerob• Penularan:
– Melalui makanan yang terkontaminasi
• Serotipe penting: IVb
Listeria monocytogenes (lanj)
• Perinatal human listeriosis (granulomatosis infantiseptica infeksi intra uterin– Eraly onset – intrauterin sepsis– Late onset – meningitis
• Listeriosis dewasa:– Meningoensefalilis– Bakteremia
• Terapi: ampisilin, eritromisin
Schematic representation of the pathophysiology of Listeria infection.
Poliovirus
Pendahuluan• Enterovirus terdiri atas:
– Poliovirus– Coxsackie A dan B– Echovirus– Enterovirus
• Termasuk famili Picornaviridae, ada 6 genus:– Enterovirus– Rhinovirus– Hepatovirus Hepatitis A virus d/h enterovirus tip 72– Parechovirus– Aphthovirus– Cardiovirus
Poliomyelitis
Poliomyelitis
• Merupakan infeksi akut dan dapat menyerang SSP flaccid paralysis (lumpuh layuh)
• Disebabkan oleh virus polio• Poliovirus diinaktivasi
– pada suhu 55oC selama 30 menit– Klorin konsentrasi 0,1 ppm, tapi pada limbah
memerlukan konsentarsi lebih• Ada tiga tipe poliovirus (1, 2, 3)
Poliomyelitis
• Virus Polio:– Virus RNA, single stranded, tidak berenvelop
replikasi di sitoplasma– Hospesnya terbatas (manusia, kera simpanse)– Memerlukan reseptor spesifik pada primata– In vivo virus tidak berreplikasi di sel otot
Poliomyelitis
• Gambaran klinis:– Masa inkubasi 7 – 14 hari– Kebanyakan infeksi bersifat subklinis– Bentuk klinis:
• Abortive poliomyelitis• Nonparalytic Poliomyelitis (aseptic meningitis)• Paralytic poliomyelitis• Progressive Postpoliomyelitis Muscle Atrophy
(Postpolio syndrome)
Poliomyelitis
• Diagnosis laboratorium:– Virus dapat ditemukan pada
• usap tenggorok• Usap rektum atau feses
– Sampel harus disimpan dalam keadaan beku selama transportasi ke laboratorium
– Pemeriksaan serologi melihat kenaikan titer• Progran pemberantasan polio gerakan
dunia.
Poliomyelitis
• Epidemiologi:– Manusia merupakan reservoir utama– Penularan melalui rute fekal – oral
• Pencegahan:– Vaksinasi dengan OPV atau IPV– Trivalent OPV dipakai dalam PPI dan PIN
Inactivated Polio Vaccine (IPV/Salk)
• Mengandung ketiga serotipe• Dikultur pada sel Vero• Diinaktivasi dengan formaldehida• Mengandung 2-phenoxyethanol, neomycin,
streptomycin, polymyxin B• Sangat efektif menimbulkan imunitas
terhadap poliovirus• Tidak terbentuk kekebalan mukosal
Oral Polio Vaccine (OPV/Sabin)
• Mengandung ketiga serotipe• Dikultur pada sel Vero• Mengandung neomycin, streptomycin• Virus dapat ditemukan di feses selama 6 minggu
sesudah vaksinasi• Sangat efektif menimbulkan imunitas terhadap
poliovirus• Terbentuk kekebalan mukosal IgA• Imunitas mungkin seumur hidup• Dapat menimbulkan VAPP (vaccine-associated
paralytic poliomyelitis)
Aseptic Meningitis
• Merupakan akut meningitis• Virus penyebab:
– Poliovirus– Echovirus– Coxsackievirus– Mumps virus
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