MICROORGANISMS CAUSING CARDIAC INFECTIONSDr.TETTY AMAN NASUTION, MMedScDepartemen Mikrobiologi FK USUMedan

CARDITISCarditis inflammation of the heart3 categories:

Pericarditis - Inflammation of the pericardium Myocarditis - Inflammation of the heart muscle Endocarditis - Inflammation of the endocardium

Microorganisms Causing Cardiac InfectionsEndocarditisStreptococcus spp (60-80%) Staphylococcus spp (20-35%) Batang Gram Neg. (2-13%)Bakteri lain2 (5%)Jamur (2-4%)Kultur negatif (5-25%)

Myocarditis / Virus : Enterovirus, Adenovirus, Herpes virus, Pericarditis Influenzae virus, Parainfluenza virus.

Bakteri: Staphylococcus aureus, Streptococcus pneumoniae, Enterobacteriaceae, Mycobacterium tuberculosis, Mycoplasma pneumoniae

Fungi

INFEKSIPENYEBAB TERBANYAKDIAGNOSE LABORATORIUMEndocarditisStreptococcus spp (60-80%)3 sampel untuk kultur darah yang di-ambil pada 3 daerah berbeda dilakukan pengambilan 1 2 jam sebelum pemberian antimikroba.

Sampel darah diambil 1 sampel untuk anaerob dan satu untuk kultur aerobic masing2 10 20 mlStaphylococcus spp (20-35%)Batang Gram Neg. (2-13%)Bakteri lain2 (5%)Jamur (2-4%) (Candida)Kultur negatip (5-25%)Myocarditis / PericarditisVirusEnterovirusPemeriksaan serologic, jika perlu dikombinasikan dengan kultur dan untuk PCR.AdenovirusHerpes virusInfluenzae virusParainfluenza virusBakteriStaphylococcus aureusPemeriksaan mikroskopis dan kultur. Tes DNA jika perluStreptococcus pneumoniaeEnterobacteriaceaeMycobacterium tuberculosisMycoplasma pneumoniaeTes serologik

Kayser, Medical Microbiology, 2005

INFEKSIPENYEBAB TERBANYAKDIAGNOSE LABORATORIUMBakteriStaphylococcus aureusPemeriksaan mikroskopis dan kultur. Tes DNA jika perluStreptococcus pneumoniaeEnterobacteriaceaeMycobacterium tuberculosisMycoplasma pneumoniaeTes serologikNeicceriae sppKultur dan mikroskopisGram negative anaerobActinomyces & NocardiaRickettsiaTes serologikChlamydia trachomatisFungiCandida sppMikroskopik dan kultur jamurJika perlu PCRAspergillus sppCryptococcus neoformansProtozoaToxoplasma gondiiMikroskopik dan kultur jamurJikas perlu PCRTrypanosoma cruziHelminthesTricinella spiralisTes serologik

Sterile Site:

BloodCerebrospinal fluidPleural fluid Peritoneal fluid Pericardial fluidSurgical aspirate, bone, or joint fluid Amniotic fluidSurgically obtained tissue

Non-Sterile Site:Normal flora:Respiratory TractEar, Eye, MouthSkin ( Wound & Abscess)Urine (Including Mid-Stream)Feces

Infective EndocarditisFebrile illnessPersistent bacteremiaCharacteristic lesion of microbial infection of the endothelial surface of the heart

Variable in sizeAmorphous mass of fibrin & plateletsAbundant organismsFew inflammatory cellsthe vegetation

ClassificationOLDSubacute Bacterial EndocarditisDeath in 3-6 monthsAcute Bacterial EndocarditisDeath in < 6 weeksNEWNative Valve EndocarditisProsthetic Valve Endocarditis

Epidemiology Infective EndocarditisAdult population : Rheumatic Heart Disease20 25% of cases of IE in 1970s & 80s 7 18% of cases in recent reported seriesMitral site more common in womenAortic site more common in menCongenital Heart Disease10 20% of cases in young adults 8% of cases in older adultsPDA, VSD, bicuspid aortic valve (esp. in men>60)

Pediatric populationThe vast majority (75-90%) of cases after the neonatal period are associated with an underlying congenital abnormalityAortic valveVSDTetralogy of FallotRisk of post-op infection in children with IE is 50%

Characteristics Infective EndocarditisTypically involves the valves :May involve all structures of the heartChordae tendinaeSites of shuntingMural lesionsInfection of vascular shunts endarteritis (lesion is the same)

Infective EndocarditisPathogenesisEndothelial damagePlatelet-fibrin thrombiMicroorganism adherence

Pathogenesis Endocarditis Exposed extracellular matrix from vascular damage can bind bacteriaClotting cascade is stimulated by exposed extracellular matrix, which encapsulates the bacteria within the lesion

Characteristics of Causative OrganismsAdherence factors critical for growth in the vegetationCan adhere to damaged valves (Staph, Strep and Enterococci have adhesins that mediate attachment)Staph adhesin binds fibrinogen and fibronectinBacteria trigger tissue-factor production from local monocytes and induce platelet aggregation so the organisms become enveloped in the vegetationProtection from immune clearance leads to large numbers of bacteria (109-1010 per g of tissue)

In the vast majority of patients, endocarditis can be effectively treated with medication and/or surgery.

Nevertheless, endocarditis can cause serious damage or even death if left untreated.

Risk FactorsStructural heart diseaseRheumatic, congenital, agingProsthetic heart valvesIntravenous drug abuseInvasive procedures (?)Indwelling vascular devicesOther infection with bacteremia (e.g. pneumonia, meningitis)History of infective endocarditis

Risk Factor Infective EndocarditisIntravenous Drug AbuseRisk is 2 5% per patient/yearTendency to involve right-sided valvesDistribution in clinical series46 78% tricuspid24 32% mitral 8 19% aorticUnderlying valve normal in 75 93%S. aureus predominant organism (>50%, 60-70% of tricuspid cases)

Prosthetic Valve IEStaphylococci most commonCoagulase negative staphylococciEnterococcusNutritionally variant streptococciFungi

Many species of bacteria and fungi

Portals of entry : = Oral, skin, URI : S. viridans, Staphylococci, HACEK = GI : S. bovis (ass. Polyps & colonic tumors) : Gram negative (Enterobacteriacae) = GU : Enterococci = Nosocomial : intravascular catheters : S.aureus

Etiologic agent Infective EndocarditisMicrobiologyNeonates: S. aureus, coag staph, group B strepOlder children: 40% strep, S. aureus

Adult Cases :streptococcus, staphylococcus, enterococcus, or fastidious gram negative cocco-bacillary forms : Gram negative organisms :P. aeruginosa most commonHACEK

Etiologic agent Infective EndocarditisStaphylococcus aureus (30-40%)Viridans group streptococci (18%)Enterococci (11%)Coagulase-negative staphylococci (11%)Streptococcus bovis (7%)Other streptococci (5%)Non-HACEK Gram negatives (2%)HACEK Organisms (2%)Fungi (2%)Culture negative (2-20%)

Etiologic agent Infective EndocarditisStreptococcus viridans accounts for more than 50% of streptococci causing infective endocarditis, including S. defectivus and S. adjacens

Enterococci ~ 5% S pneumoniae, Beta streptococci rare

Staphylococci: especially post-operatives or in normal hearts.Staph. aureus ~ 10-15%Coagulase-negative ~ 10%

Others -5% Fungi especially Candida

Infective EndocarditisGram negative organismsP. aeruginosa most commonHACEK - slow growing, fastidious organisms that may need 3 weeks to grow out of cultureHaemophilus sp.ActinobacillusCardiobacteriumEikenellaKingella

Streptococcus sanguisLike other oral viridans streptococci, S. sanguis commonly enters the bloodstream following dental procedures

Adhesins (e.g. SsaB) and the glycocalyx contribute to infectivity

By facilitating the formation of a vegetation on damaged heart valves for S. sanguis to colonize, the glycoprotein PAAP (platelet aggregation-associated protein) is a particularly important determinant of virulence that explains why S. sanguis is one of the most prominent streptococcal species involved in IE

EctoATPase expressed on the surface of S. sanguis enhances the platelet-aggregating properties of PAAP

Herzberg, M. C. Crit Rev Oral Biol Med 1996;7(3):222-236

DIAGNOSIS IE: Because the clinical features of the disease can be quite variable and often nonspecific, diagnosis is mainly based on laboratory tests.

Blood culture and serologic testing are the most important. Always use venous blood to isolate the organism.

A positive blood culture with some or all of the symptoms listed is needed to obtain the diagnosis.

Microbiology Diagnostic BLOOD CULTUREMULTIPLE BLOOD CULTURES BEFORE EMPIRIC THERAPY :If not critically ill3 blood cultures over 12-24 hour period? Delay therapy until diagnosis confirmedIf critically ill3 blood cultures over one hourNo more than 2 from same venipunctureRelatively constant bacteremia

From another reference :3 sampel untuk kultur darah yang di-ambil pada 3 daerah berbeda Dilakukan pengambilan 1 2 jam sebelum pemberian antimikroba

Sampel darah diambil 1 sampel untuk anaerob dan satu untuk aerobic Masing-masing 10 20 ml (Kayser, Medical Microbiology, 2005)

Intravascular infections

Originate from the cardiovascular system

Cardiac abnormalities, trauma from intraveneous catheters

Damage cardiac endothelium

Deposition of platelets and fibrin

Organisms may stick to and then colonized

Bacterial multiplication (endocarditis)Transient bacteria

Extravascular infections

Bacterial entering the blood circulation through the lymphatic system from another site of infectionPortal of entryGenitourinary tract 25%Respiratory tract 20%Abscesses 10 %Surgical wound infections 5 %Biliary tract 5%Miscellaneous site 10%Uncertain site 25%Depend on the site of infection, severity, and organisms

Bacteremiapresence of viable bacteria in the blood streammay or may not have symptomspositive blood culture

Bacteremic episodesIntermittent bacteremiabacteria are release into the blood approximately 45 minutes before a febrile episodeCommon cause of bacteremia

Transient bacteremiaAppear for a brief period following dental, colonoscopicBacterial are indigenous flora

Septicemia or sepsisSepticemia is bacteremia plus a clinical presentation of physical signs and symptoms of the bacteria invasion and toxin productionfever, chills, tachycardia, hypotention, mental confusion

Complication : septic shock, DIC, acute renal failure

Mortality rate: age, underlying condition and therapy

Detection of BacteremiaSpecimen collectionSpecimen volumeNumber of blood cultureMiscellaneous

Specimen collectionsUniversal precautions Aseptic techniques

Specimen volume & number of blood culturesBacteremia in adults have a number of CFU < 30 CFU/mlAdults 10-20 ml, minimal 10 mlChildren 1-5 ml Number of blood cultures1 bottles 80-92%2 bottles 90-99%3 bottles 99.6% (be space an hour apart)

Timing of collection > 1 hr influx of bacteria fever, chill normal host defense mechanisms

bacteria was cleared

Ideal 30 min. before peak temperature

Blood culture mediaTrypticase soy broth or Brain heart infusion brothThio broth or thioglycolate broth Blood : culture media = 1:10 (5:50)neutralized bactericidal property of bloodhigh ratio : prolonged detection timelow ratio : inhibit by serum factors

Anticoagulant0.025-0.05% Sodium polyanetol sulphonate (SPS)Inactivate neutrophilsInactivate antimicrobial (amonoglycosides, polymixin)Inhibit phagocytosisInhibit growth of Neisseria gonorrhoea, N. meningitidisPrevent by add 1-1.2% gelatinHeparin, EDTA, and citrate inhibit numerous organisms

Additives10-20% Hypertonic sucrose or sorbitolPenicillinaseAntimicrobial-adsorbing (resin): nonspecific adsorbtion

Incubation at 35-370C and 5% CO2Ventilation for strictly aerobe (Pseudomonas, and fungi)

Culture techniquesConventional cultureLysis centrifugationAutomated blood culture system

Conventional cultureCulture mediaTSB 50 ml, 10 ml0.025% SPS1-1.2% gelatin5% CO2Blood sampleAdults 5 ml, 3 bottlesChildren 1 ml, 2 bottles

Conventional cultureBlind subcultureBlind aerobic subculture : after 24 hrsBlind anaerobic subculture : after 48 hrsEarly blind subculture : after 6- 18 hrsFinal subculture : after 5-7 days (bacteria) or 14 days (fungal) Chocolate agar at 35-370C and 5% CO2

Conventional cultureMicroscopic examinationGrams stain (105 CFU/ml)

Conventional cultureMacroscopic examinationSign of growth (106-107CFU/ml)TurbidityGas bubbles in the mediumHemolysis of RBCsThe appearance of small aggregates of bacterial or fungal growth on the surface of sedimented RBC

Automated blood culture system

Automated blood culture systemBecT/Alert (Organon Teknika)

BACTEC 9240 (Becton Dickinson)

BecT/AlertDetection unit- 120, 240 cells- agitate continuously- monitored 144 times/days (10 min. interval)Computer system

BecT/AlertCulture medium- 20, 30, 40 ml. Trypticase soy broth- up to 4 ml. blood (pediatric) - up to 10 ml. blood (adult)- anticoagulant = SPS- supplements with BHI solids and activated charcoal

Positive Negative

CO2 semipermeable colorimetric sensor membrane (saturated with water)

CO2 + H2O H2CO3 H+ + HCO3-

pH change

color of the sensor change from dark green to yellow

BACTEC 9240Continuous monitoring to provide the earliest possible detectionResin-based media to neutralize antimicrobials and enhance recoveryFluorescence-based technology to provide high sensitivity

Culture Negative IELess common with improved blood culture methodsSpecial media required :Brucella, Mycoplasma, Chlamydia, Histoplasma, Legionella, BartonellaLonger incubation may be requiredHACEKCoxiella burnetii (Q Fever), Trophyrema whipplei will not grow in cell-free media

Other microbiologic methodsPCRCoxiella burnetiiTropheryma whippleiBartonella henselae

SerologyCoxiella burnetiiBartonellaBrucellaLegionellaChlamydophila psittaci

Candidal EndocarditisSevere condition that has been traditionally associated with an exceptional high mortality and recurrence rates. Both native and prosthetic valves may be affected. Combining medical with surgical interventions, the hospital survival rates have been commonly below 50%. The highest long term survival rate is 67% Open heart surgery is one of the most frequent risk factors for fungal endocarditis, with a rate of 0.23% to 1% of all cardiac surgeries.Fungal prosthetic valve endocarditis has been reported to be 9.6% and 4.3%, respectively. Intravenous drug abusers have the highest rates of fungal endocarditis. Candida spp. account for between 50 and 60% of cases Neonates may develop endocarditis as part of the picture of disseminated neonatal candidiasis. Candida spp. causes all of the infections.

Candidal PericarditisRare but serious condition that can lead to severe sepsis, cardiac tamponade and death if not diagnosed and treated promptly Candidal pericarditis may occur in relation to obvious hematogenous seeding from invasive candidiasis

Candida albicans is the most frequent species, followed by C. tropicalis. Of the 26 cases reviewed by Rabinovici et al. only 18 had species identification. Of these 78% of them were caused by Candida albicans.

Candidal Endocarditis (laboratory diagnostic)Blood cultures. The sensitivity of blood cultures to detect invasive candidiasis is generally low. However, the intravascular site of this infection changes that rule.

Rates of 83 to 95% of positive blood cultures for Candida spp. have been reported in reviews of fungal endocarditis In the review by Nguyen et al. of 18 prospectively identified cases of candidal prosthetic valve endocarditis, all patients had several positive blood cultures. The mean and median number of positive blood cultures for this group were 7 and 5 respectively

Candida species and Candida PericarditisCandida albicans is the most frequent species, followed by C. tropicalis.

Specific Diagnostic StrategiesTo make the diagnosis of Candida pericarditis, one should : Recognize the patient populations at risk, Perform an echocardiogram when suspecting the picture, Perform a pericardiocentesis, Isolate Candida from the pericardial fluid or tissue, and Ideally, have a histopathologic confirmation of yeast forms in pericardial tissue.

TherapiesTreating Candida pericarditis requires an aggressive approach that combines surgical and medical treatment.Prolonged courses of amphotericin B but the precise length of therapy is not defined

Less prevalent causative agents includeOther bacteriaThe HACEK GroupHaemophilus species, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella speciesUsual bacterial causesBacillus cereus, Clostridium perfringens, Mycobacterium tuberculosis, Nocardia asteroides, Coxiella burnetii, etc.FungiCandida and Aspergillis species

Pericarditis

An inflammation of the pericardium, the thin, fluid-filled sac surrounding the heart. It can cause severe chest pain (especially upon taking a deep breath) and shortness of breath.

Also called: Adhesive Pericarditis, Postmyocardial Pericarditis, Acute Pericarditis, Bacterial Pericarditis, Polyserositis, Chronic Pericarditis, Constrictive Pericarditis.

Most patients with pericarditis also have some fluid in the pericardial sac.

*PericarditisOften local manifestation of another diseaseMay present as: Acute pericarditisPericardial effusionConstrictive pericarditis

*Acute PericarditisAcute inflammation of the pericardiumCause often unknown, but commonly caused by infection, uremia, neoplasm, myocardial infarction, surgery or trauma.Membranes become inflamed and roughened, and exudate may develop

*Pericardial effusionAccumulation of fluid in the pericardial cavityMay be transudateMay be exudateMay be bloodNot clinically significant other than to indicate underlying disorder, unless:Pressure becomes sufficient to cause cardiac compression cardiac tamponade

*Constrictive (chronic) pericarditisYears ago, synonymous with T.B.Today, usually idiopathic, or associated with radiation exposures, rheumatoid arthritis, uremia, or coronary bypass graft

Myocarditis Also called: Fulminant Myocarditis, Acute Myocarditis

An uncommon inflammation of the heart muscle (myocardium). can be caused by infectious agents, toxins, drugs or for unknown reasons. may be localized to one area of the heart, or it may affect the entire heart.Approximately 50% of the time, myocarditis is classified as idiopathic although a viral etiology is often suspected but unproved.

Myocardial damage - mechanismsDirect toxic action of the infectious agent on the myocyte (C. Chauvoei, L. monocytogenes)Indirectly, through circulating toxic products that are released from an overwhelming infection (sepsis)Immune-mediated mechanisms, cellular or antibody-mediated (chronic infections)

PathogenesisThree phases: Viral Replication

Autoimmune injury Dilated cardiomyopathy

Etiology Agents of MyocarditisViral - Enterovirus, coxsackie B, adenovirus, influenza, cytomegalovirus, poliomyelitis, Epstein-Barr virus, HIV-1, viral hepatitis, mumps, rubeola, varicella, variola/vaccinia, arbovirus, respiratory syncytial virus, herpes simplex virus, yellow fever virus, rabiesRickettsial - Scrub typhus, Rocky Mountain spotted fever, Q feverBacterial - Diphtheria, tuberculosis, streptococci, meningococci, brucellosis, clostridia, staphylococci, melioidosis, Mycoplasma pneumoniae, psittacosisSpirochetal - Syphilis, leptospirosis / Weil disease, relapsing fever/Borrelia, Lyme diseaseFungal - Candidiasis, aspergillosis, cryptococcosis, histoplasmosis, actinomycosis, blastomycosis, coccidioidomycosis, mucormycosis

Etiology Agents of MyocarditisViruses : Enteroviruses Influenza A and B Adenovirus Herpes HIV

Bacteria : Beta-hemolytic Streptococcus Corynebacterium diphtheria Borrelia burgdorferi Enterococcus spp Chlamydia psittaci Neisseria meningitidis Mycoplasma pneumonia Staphylococcus aureus

pto

Viral Myocarditis Coxsackievirus A9 is a self-limiting myocarditis, whereas coxsackievirus B3 causes severe myocarditis resulting in a high mortality rate.

Approximately 50% of the time, myocarditis is classified as idiopathic, although a viral etiology is often suspected but unproved Viral - Enterovirus, coxsackie B, adenovirus, influenza, cytomegalovirus, poliomyelitis, Epstein-Barr virus, HIV-1, viral hepatitis, mumps, rubeola, varicella, variola/vaccinia, arbovirus, respiratory syncytial virus, herpes simplex virus, yellow fever virus, rabies

Viral MyocarditisViral myocarditis results when the muscles in the walls of heart become infected with a virus. Enteroviruses and adenoviruses are the primarycausative agents of viral myocarditis.

SymptomsFever Cough Nausea Vomiting Myalgia Arthralgia Palpitation Heart failure (in severe cases)

Candidal MyocarditisHematogenous seeding of Candida into the myocardium was frequently found in the early autopsy reviews of patients dying with systemic invasive candidiasis.

The lack of inflammatory response is most notable in immunosuppressed patients

Chlamydia pneumoniae as an emerging risk factor in cardiovascular disease. Seroepidemiologic studies have associated C. pneumoniae antibody with coronary artery disease, myocardial infarction, carotid artery disease, and cerebrovascular disease. The association of C. pneumoniae with atherosclerosis is corroborated by the presence of the organism in atherosclerotic lesions throughout the arterial tree and the near absence of the organism in healthy arterial tissue. C. pneumoniae has also been isolated from coronary and carotid atheromatous plaques.

Compelling evidence of the association between C. pneumoniae and atherosclerosis has been obtained by polymerase chain reaction (PCR), immunocytochemical (ICC) staining, and electron microscopy, which have detected C. pneumoniae in atherosclerotic lesions

A causative role of C. pneumoniae infection in cardiovascular disease has not yet been firmly established. However, the high frequency of infection found in human atherosclerotic tissue in comparison to normal tissue, the induction and progression of atherosclerotic-like inflammatory changes in infected animal models of atherosclerosis, and the early results from antichlamydial intervention studies in humans are consistent with a causative role of C. pneumoniae in the disease process.

Infection, inflammation and atherosclerosisC. pneumoniae, H. pylori, Porphyromonas gingivalis, Cytomegalovirus, Herpes simplex virus, Hepatitis A, B, and C virus linked with an increased risk of cardiovascular diseases Pro inflammatory effects of infection increased CRP, cytokines

MYOCARDIAL INFARCTIONMyocardial infarction can occur in the absence of the common risk factors such as hypercholesterolemia, diabetes mellitus or cigarette smoking. The sequence of events that leads to acute myocardial infarction includes atherosclerotic plaque formation, plaque rupture, coronary artery thrombosis and coronary occlusion. Anything that leads to plaque rupture can result in myocardial infarction.

ETIOLOGY: Chylamydia pneumoniae, a Gram-, pleomorphic, obligate intracellular parasite.

DIAGNOSIS MYOCARDIAL INFARCTION : 1.Non-specific indices of tissue necrosis and inflammation a.Polymorphonuclear leukocytosis b.Erythrocyte sedimentation rate that rises more slowly than the WBC count

2.The electrocardiogram 3.Serum enzyme changes a.Creatine phosphokinase (CK) b.Lactic dehydrogeinase (LDH)

4.Cardiac imaging 5.Presence of chlamydia in the plaque 6.Presence of antibiodies to C. pneumoniae

Cardiovascular Syphilis Although morphological involvement of the cardiovascular system occurs in 80% of cases of tertiary syphilis only about 10% of these are manifested clinically.

The spirochetes evoke endarteritis in the vasa vasorum of the aorta and coronary ostia. Clinical manifestations occur in 15 - 30 years after infection.1 Aortic aneurysm2 Aortic Valve Disease3 Coronary Artery Disease

Mucous membrane or other Valvular endothelium colonized tissue trauma turbulence metabolicPlatelet-fibrin deposition Trauma

Nonbacterial thrombotic Bacteremia endocarditis (NBTE) Complement Ab Adherence

Colonization bacterial division fibrin depositon platelet aggregation extracellular proteases neutrophils protection mature vegetation

*Sterile Site means a site that is..free from Group B Streptococcus is also reportable if the source is placenta or amniotic fluid in the case of fetal demise. Group A Streptococcus is also reportable if the source is surgically obtained tissue, or from any site (even non-sterile sites) in a case of toxic shock syndrome or necrotizing fasciitis.Sterile Site :A normally sterile site is defined as blood, cerebrospinal fluid, pleural fluid, peritoneal fluid, pericardial fluid, surgical aspirate, bone, or joint fluid.

*