Microorganisms Causing Cardiac Infections Dr. Edhie Djj,pohan Utama, SpMK Dep. Mikrobiologi FKUSU MedanM e d a n CARDITIS Carditis,,, or inflammation of the heart, is most conveniently broken down into three categories: Pericarditis - Inflammation of the pericardium Myocarditis - Inflammation of the heart muscle Endocarditis - Inflammation of the endocardium Classification • OLD – Subacute Bacterial Endocarditis • Deathin3Death in 3-6 months – Acute Bacterial Endocarditis • Death in < 6 weeks • NEW – Na tive Va lve En docar ditis – Prosthetic Valve Endocarditis INFEKSI PENYEBAB TERBANYAK DIAGNOSE LABORATORIUM EdEndocar ditis Streptococcus spp (60 -80%) 3ltkkltdhdi3 sampel untuk kultur darah yang di-ambil Staphylococcus spp (20- pada 3 daerah berbeda dilakukan 35%) pengambilan 1 – 2 jam sebelum pemberian Batang Gram Neg. (2-13%) antimikroba. Bakteri lain2 (5%) Jamur (2-4%) (Candida) Sampel darah diambil 1 sampel Kultur negatip (5-25%) untuk anaerob dan satu untuk kultur aerobic masi210ing2 10 – 20 m l Myocarditis / Pericarditis Virus Enterovirus Pemeriksaan serologg,jic, jika p erlu Adenovirus dikombinasikan dengan kultur dan untuk Herpes virus PCR. Influenzae virus Parainfluenza virus Bakteri Staphylococcus aureus Pemeriksaan mikroskopis dan kultur. Tes Streptococcus pneumoniae DNA jika perlu Enterobacteriaceae Mycobacterium tuberculosis Mycoplasma pneumoniae Tes serologik INFEKSI PENYEBAB TERBANYAK DIAGNOSE LABORATORIUM Baaekteri Staphylococcus aureus Peeemeriksaa n mikros osopsdauu.eskopis dan kultur. Tes Streptococcus pneumoniae DNA jika perlu Enterobacteriaceae Mycobacterium tuberculosis Mycoplasma pneumoniae Tes serologik Neicceriae spp Kultur dan mikroskopis Gram negative anaerob Actinomyces & Nocardia Rickettsia Tes serologik Chlamy dia t rach omati s Fungi Candida spp Mikroskopik dan kultur jamur Aspergillus spp Jikas perlu PCR CfCryptococcus neoformans Protozoa Toxoplasma gondii Mikroskopik dan kultur jamur Trypanosoma cruzi Jikas perlu PCR Helminthes Tricinella spiralis Tes serologik Kayser, Medical Microbiology, 2005 Infective Endocarditis • Adu lt popu la tion : – Rheumatic Heart Disease • 20 – 25% of cases of IE in 1970’s & 80’s • 7 – 18% of cases in recent reported series • Mitral site more common in women • Aortic site more common in men – Congenital Heart Disease • 10 – 20% of cases in young adults • 8% of cases in older adults • PDA, VSD, bicuspid aortic valve (esp. in men>60) • Pediatric population – The vast majority (75-90%) of cases after the neonatal period are associated with an underlying congenital abnormality • Aortic valve • VSD • Tetralogy of Fallot – Ris k o f pos t-op in fec tion in c hildren w ith IE is 50% Infective Endocarditis • Typically involves the valves : – May involve all structures of the heart • Chordae tendinae • Sites of shunting • Mural lesions – IfInfecti on of vascul ar sh unt s, b y st titrict definition, is endarteritis, but lesion is the same Infective Endocarditis • Pathogenesis Endothelial damage Platelet-fibrin thrombi Microorganism adherence Characteristics of Causative Organisms • Adherence factors critical for growth in the vegetation – Can adhere to damaged valves (Staph, Strep and Enterococci have adhesins that mediate attachment) – Staph adhesin binds fibrinogen and fibronectin – Bacteria trigger tissue-factor production from local monocytes and induce platelet aggregation so the organisms become enveloped in the vegetation – Protection from immune clearance leads to large numbers of bacteria (109-1010 per g of tissue) • In the vast majjyority of patients, endocarditis can be effectively treated with medication and/or surggyery. • Nevertheless, endocarditis can cause serious damage or even death if left untreated. S. Aureus mitral valve vegetation, antiterior lea fltflet Risk Factors • Structural heart disease – Rheumati c, congen ita l, ag ing – Prosthetic heart valves • IjInjec tddted drug use • Invasive procedures (?) • Indwelling vascular devices • Other infection with bacteremia (e.g. pneumonia, meningitis) • History of infective endocarditis Infective Endocarditis • Intravenous Drug Abuse – Risk is 2 – 5% per pt./year – Tendency to involve right-sided valves • Distribution in clinical series – 46 – 78% tricuspid – 24 – 32% mitral – 8 – 19% aortic – Underlying valve normal in 75 – 93% – S. aureus predominant organism (>50%, 60- 70% of tricuspid cases) Infective Endocarditis Microbiology – Neonates : S. aureus, coag – staph, group B strep – Older children : 40% strep, S. aureus • Majority of cases caused by (Adult Cases) : – streptococcus, – stappyhylococcus, – enterococcus, or – fastidious gram negative cocco-bacillary forms : Gram negative organisms : • P. aeruginosa most common • HACEK - slow growing, fastidious organisms that may need 3 weeks to grow out of culture – Haemophilus sp. – Actinobacillus – Cardiobacterium – Eikenella – Kingella INFECTIVE ENDOCARDITIS • Staphylococcus aureus (30-40%) • Viridans gg()roup 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%) • Portals of entry : = Oral, skin, URI : S. viridans, Staphylococci, HACEK =GI= GI : S. bovis (ass. Polyps & colonic tumors) : G –ve (Enterobacteriacae) = GU : Enterococci = Nosocomial : intravascular catheters : S.aureus Like other oral viridans streptococci, S. sanguis commonly enters the bloodstream following dental procedures Infective Endocarditis • Gram negative organisms – P. aeruginosa most common – HACEK - slow growing, fastidious organisms that may need 3 weeks to grow out of culture • Haemophilus sp. • Actinobacillus • Cardiobacterium • Eikenella • Kingella • Like o ther ora l v ir idans s trep tococc i, SiS. sanguis commonly enters the bloodstream following dental procedures Prosthetic valve : 2mo , NI : Intraoperative contamination : Bacteremic postoperative : S.coag.-ve, S. aureus, G-ve rod, diphtheroids, fungi : >12mo. = Community-acquired native valve :>85% S.coag-ve : MRSA Transvenous pacemaker and/or implanted defibrillator : NI , within weeks, S. aureus, S.coag –ve Injection drug users -TV - S. aureus strains : MRSA - Lt side : varied etiology & abnormal valve : P.aeruginosa, Candida spp., : Bacillus, Lactobacillus, : Corynebacterium -Polymicrobial Causative organisms of infective endditidocarditis • Enterococci* • Viridans streptococci* • Staphylococcus aureus* • Coagulase-negative staphylococci • Enterobacteriace *most common organisms associated with native valve endocarditis Native Valve IE • Viridans Streptococci and S. bovis – Aqueous Penicillin G 12-20 million units/day continuously or divided q4 or q6 for 4 weeks – If intermediate susceptibility to penicillin, aqueous penicillin G 24 million units or ceftriaxone 2 g q24 PLUS aminoglycoside for the first 2 weeks • Aminoglycosides for synergy – Low concentrations are adequate (1-3 mcg/ml) – Gentamicin 3 mg/kg divided q12 or q8 – Little data for q24 dosing • Enterococci, ampicillin sensitive – High rates of failure – β-lactams are bacteriostatic, must combine with aminoglycoside for optimal therapy – High-level gentamicin resistance occurs in 35% • High-dose ampicillin for 8-12 weeks • Enterococci,,p ampicillin resistant – Vancomycin plus gentamicin • Enterococci, vancomycin resistant – Linezolid or daptomycin – Penicillin + vancomycin + gentamicin ? 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 serologggic testing are the most im portant. 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. • Blood is normally considered sterile • Means of delivery for many microbial agents • Primary viremia/bacteremia clinically inapparent • Secondary viremia/bacteremia have clinical signs due to activation of inflammatory process Detection of Bacteremia • Specimen collection • Specimen volume • NbNumber o fbldltf blood culture • Miscellaneous • Universal precautions • Aseptic techniques Blood Cultures (Microbiology Diagnostic) 3 sampel untuk kultur darah yang di-ambil pada 3 daerah berbeda Dilakukan pengambilan 1 – 2 jam sebelum pemberian antimikroba Sampe l dara h diam bil 1 sampe l un tu k anaero b dan sa tu un tu k kult ur aerobic masing2 10 – 20 ml (Kayser, Medical Microbiology, 2005) Literatur lain : MULTIPLE BLOOD CULTURES BEFORE EMPIRIC THERAPY : • If not critically ill – 3 blood cultures over 12-24 hour period – ? Delay therapy until diagnosis confirmed • If critically ill – 3 blood cultures over one hour • No more than 2 from same venipuncture • Relatively constant bacteremia Specimen volume & number of blood cult ures • Bacteremia in adults have a number of CFU < 30 CFU/ml • Adults 10-20 ml, minimal 10 ml • Children 1-5 ml • Number of blood cultures – 1 bottles 80-92% – 2 bottles 90-99% – 3 bottles 99.6% (be spppace an hour apart) Lecturer: Kanya Preechasuth : Clinical microbiology, Faculty of Associated Medical Sciences, CMU, Jan 12, 2006 Timing of collection > 1 hr influx of bacteria fever, chill normalhl host de fense mec han isms bacteria was cleared Ideal 30 min. before peak temperature Miscellaneous • Blood culture media – Trypticase soy broth or Brain heart infusion broth – Thio broth or thioglycolate broth – Blood : culture media = 1:10 (5:50) • neutralized bactericidal property of blood • high ratio : prolonged detection time