Recebido para publicação: Outubro 2010 • Aceite para publicação: Fevereiro 2011Received for publication: October 2010 • Accepted for publication: February 2011

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ARTIGOS ORIGINAIS

Acute bivalvular left-sided methicillin-resistant Staphylococcus

aureus endocarditis with cardiac, cerebral, renal and septic complications [48]

DIANA PÓVOAS1, MANUEL DE FIGUEIREDO1, ANTÓNIO MURINELLO1, HELENA DAMÁSIO1, ALEXANDRA RAMOS2, NUNO RODRIGUES3,JOÃO SOUSA3, FERNANDA CARVALHO4, HELENA PERES5, PATRÍCIA GOMES1

Institution and Units: 1. Unit of Internal Medicine, Hospital Curry Cabral, Lisbon, Portugal2. Unit of Cardiology, Hospital Curry Cabral, Lisbon, Portugal3. Unit of Nephrology, Hospital Curry Cabral, Lisbon, Portugal

4. Laboratory of Renal Pathology, Unit of Nephrology, Hospital Curry Cabral, Lisbon, Portugal5.Unit of Clinical Pathology, Hospital Curry Cabral, Lisbon, Portugal

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ABSTRACT

Infective endocarditis (IE) is now rare indeveloped countries, but its prevalence ishigher in elderly patients with prosthetic

valves, diabetes, renal impairment, or heartfailure. An increase in health-care associat-

ed IE (HCAIE) has been observed due toinvasive maneuvers (30% of cases).

Methicillin-resistant Staphylococcus aureus(MRSA) and Enterococcus are the most com-mon agents in HCAIE, causing high mortal-

ity and morbidity.We review complications of IE and its thera-py, based on a patient with acute bivalvularleft-sided MRSA IE and a prosthetic aorticvalve, aggravated by congestive heart fail-

ure, stroke, acute immune complexglomerulonephritis, Candida parapsilosis

fungémia and death probably due toSerratia marcescens sepsis. The HCAIE was

assumed to be related to three temporallyassociated in-hospital interventions consid-

ered as possible initial etiological mecha-nisms: overcrowding in the hospital environ-

ment, iv quinolone therapy and red bloodcell transfusion. Later in the clinical course,

Endocardite aguda bi-valvularesquerda por Estafilococo aureusmeticilino-resistente com complicaçõescardíaca, cerebral, renal e sepsis

RESUMO

Em países desenvolvidos a endocarditeinfecciosa (EI) é actualmente poucofrequente, mais prevalente em idosos compróteses valvulares, diabetes, insuficiênciarenal e insuficiência cardíaca. Manobrasinvasivas causaram um aumento dasendocardites associadas a cuidadoshospitalares (HCAIE) (30% dos casos),sendo o Estafilococo aureus meticilino-resistente e o Enterococo os agentesinfecciosos mais comuns nestes casos,condicionantes de maioresmortalidade/morbilidade.Os autores revêem as complicações da EI esua terapêutica, baseados numa doente comEI aguda bi-valvular esquerda e comprótese valvular aórtica, complicada deinsuficiência cardíaca, embolia cerebral,glomerulonefrite aguda pós-infecciosa aimunocomplexos, funguémia por Candida

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INTRODUCTION

Staphylococcus aureus (SA) is a majorcause of infective endocarditis (IE) inall age-groups, accounting for around

55% of cases, and is more common in patientswith prosthetic valves or abnormal nativevalves(1). SA IE usually presents as a highlytoxic, febrile illness, with frequent focalmetastatic infection and a high rate of heartfailure and central nervous system complica-tions. New heart murmurs or modification ofprevious ones are heard initially in 30-45% ofpatients and eventually in 75-85% of cases asa consequence of progressive valve damage.

Left-sided IE due to SA in non-intravenousdrug abusers has a very high mortality rate inthose aged over 50 years and with significantunderlying diseases and when severe compli-cations occur, such as major neurologicalevents, valve dysfunction with heart failure,and renal failure due to acute glomeru-lonephritis. However, in a report from Spain,Lopez et al. (2) described more frequent valvu-lar impairment (regurgitation and perforation)due to left-sided SA endocarditis in youngerpatients, the worse prognosis in older patients

being due to comorbidities and higher surgi-cal mortality.

Patients with IE due to MRSA are signifi-cantly more likely to present renal failure andto experience bacteremia than those with IEdue to methicillin-susceptible SA (MSSA).Risk factors for death due to IE include sever-ity of illness at onset of bacteremia, MRSAinfection and atrioventricular block. MRSA asthe infecting microorganism in cases of IE isa risk factor that should be considered forpossible prompt valve resection (3).

Health-care associated IE (HCAIE) isincreasingly being reported in developedcountries, due to increasing age of patients,comorbidities (diabetes, renal impairment,previous heart valve disease, and immuno-suppressive states), and the growing numberof invasive maneuvers with their high risk ofbacteremia (4).

We report a case of an elderly femalepatient with previous left-sided bivalvularfibrocalcifying disease, a prosthetic aorticvalve, red cell blood transfusion one weekbefore, and hospitalization for acute pul-monary infection treated with iv quinolone,who developed acute left-sided bivalvular IE

C. parapsilosis and S. marcescens septicemiawere considered to be possible secondary

etiological mechanisms of HCAIE.

Key wordsMRSA; Left-sided infective endocarditis;

Prosthetic infective endocarditis; Vancomycin;Linezolid; Immune complex glomerulonephritis;

Candida parapsilosis; Serratia marcescens

parapsilosis, e “exitus” possivelmente porsepsis a Serratia marcescens. Admitiu-seHCAIE relacionada com três intervençõeshospitalares, como mecanismos etiológicosiniciais prováveis: estadia em ambientehospitalar superlotado, terapêutica e.v. comquinolona e transfusão de concentradoeritrocitário. Posteriormente, a sepsis porCandida parapsilosis e Serratia marcescensforam igualmente consideradas comohipotéticos mecanismos etiológicossecundários de HCAIE.

Palavras Chave:MRSA; endocardite infecciosa valvular esquerda;endocardite infecciosa em válvula protésica;vancomicina; linezolido; glomerulonefrite porimunocomplexos, Candida parapsilosis, Serratia marcescens

emia; hypoalbuminemia (2.56 g/dl); and nor-mal urea and creatinine, with calculated GFRof 62.3 ml/min. Urinary sediment showed 75WBCs/μl, but urine culture was negative, aswas urinary antigen for Pneumococcus andLegionella pneumophila. The chest X-rayshowed cardiomegaly and bilateral peribron-chitis.

After the first day on iv therapy with lev-ofloxacin, the patient was afebrile and improv-ing rapidly, and her WBCs were normal on the6th day of therapy (Table I). During the night of

the 8th to 9th day of hospitalization she devel-oped high fever (39 ºC), chills, vomiting,abdominal pain and headache, and a de novomitral systolic murmur (III/VI) was audible.Conjunctival petechiae and finger splinterhemorrhages were detected, but retinoscopywas normal. No hepatomegaly or splenomegalywere observed. Blood tests on the followingmorning showed recurrent and higher leukocy-tosis (Table I), and urinary sediment revealedmany erythrocytes but no proteinuria. Bloodcultures were taken and MRSA was subse-quently isolated, susceptible to gentamicin,vancomycin, teicoplanin and linezolid.Transesophageal echocardiography performedon the same day revealed a small vegetation onthe fibrocalcified native mitral valve, butapparently not on the biological prosthetic aor-tic valve. One day later right hemiparesisoccurred due to left frontal-parietal ischemicstroke. Cardiologists did not advise surgerythen or later on due to comorbidities and com-plications in an 83-year-old patient.

Therapy with vancomycin, gentamicin andrifampicin was initiated on the day of diagno-sis of endocarditis, subsequently changed tolinezolid when renal failure ensued, revealedby blood tests on the 14th day of hospitaliza-tion (plasma urea 147 mg/dl and creatinine1.9 mg/dl) (Table I), which was at first pre-sumed to be due to drug iatrogeny. However,diuresis becomes progressively lower and onDecember 22 2009 (the 22nd day of hospital-ization) the patient was in anuria with acuteelevation of renal function markers (Table I)and heart failure (NYHA class III). C3 waslower than normal, which persisted throughout 613

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on the 8th day of hospitalization due to MRSAinfection with several serious complications:heart failure, embolic stroke, anuric acuterenal failure due to post-infectious acuteimmune complex glomerulonephritis,fungemia due to Candida parapsilosis, andseptic shock due to Serratia marcescens bac-teremia following insertion of a permanenttunneled hemodialysis catheter through thelumen of a previous temporary hemodialysiscatheter. We considered our patient to be acase of HCAIE, possible mechanisms ofoccurrence of which are reviewed in theDiscussion.

CASE REPORT

An 83-year-old woman was admitted to ourinfirmary on November 12 2009 due to acutehypoxemic respiratory infection (PaO2 35.2mmHg) of one week’s duration, ten days aftera red cell transfusion in the emergency wardfor iron deficiency anemia of undiagnosed eti-ology (Hb 8.1 g/dl), presumably related towarfarin therapy. The patient complained offever, cough productive of purulent sputum,left thoracic pain and progressive dyspnea.

Her past medical history included a biolog-ical aortic valve prosthesis due to fibrocalcify-ing disease (November 2004), ischemic/hyper-tensive cardiomyopathy, chronic atrial fibrilla-tion, secondary pulmonary hypertension,ischemic stroke without sequelae, acute bron-chopneumonia and iron deficiency anemia dueto hemorrhagic gastritis (May 2009). Her fatherhad died from acute rickettsiosis and her moth-er from ischemic stroke.

On observation, her temperature was 38.5ºC, blood pressure 124/68 mmHg, heart rate~120 bpm, and respiratory rate 26/min. Anaortic systolic ejection murmur (III/VI) wasaudible, with no other abnormal sounds. Therewere bilateral diffuse rhonchi on lung auscul-tation. Abdominal semiology was normal andthere was no leg edema.

Laboratory blood tests (Table I) revealedanemia of chronic disease; leukocytosis withneutrophilia; INR 2.3; elevated CRP; hypox-

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Although three transthoracic echocardio-grams performed during the six weeks of ther-apy showed no new abnormal echocardio-graphic signs, transesophageal echocardiogra-phy performed subsequently showed anapparently new aortic valve infection withsuspected perivalvular abscess cavity (Figure4). However, urgent heart surgery was refusedby a cardiovascular surgeon, because: (1) afterserial review of all echocardiograms it wasconsidered that bivalvular endocarditis had

the clinical course, circulating immune com-plexes were persistently lower than the cut-offvalue, and from then on platelets decreasedprogressively (Table I). Meanwhile, renalbiopsy revealed endocapillary proliferativeglomerulonephritis due to immune complexdeposition (Figures 1, 2 and 3). Hemodialysisvia a temporary hemodialysis catheter was ini-tiated and, although anuria persisted, theheart failure was compensated. Vancomycinwas administered after each dialysis sessionbeginning on day 15 of renal failure, and line-zolid was maintained for six weeks (untilJanuary 4 2010), at which time acute-onsetdyspnea developed. On that day blood tests revealed worsening anemia and throm-bocytopenia; WBCs were unexpectedly nor-mal, and CRP was much lower than before(Table I).

Table 1. Evolultion of laboratory results

11.11.09 11.17.09 11.19.09 11.23.09 12.02.09 12.18.09 01.04.10

Hb (g/dl) 9.9 10.6 10.9 10.9 9.6 9.3 6.7

WBCs (x109/l) 16.0 9.8 24.7 12.6 12.9 8.6 5.4N (%) 87.2 64.6 95.0 85.9 88.2 73.4 60

Platelets (x109/l) 247.0 203.0 229.0 87.0 102.0 45.0 30.0CRP (mg/dl) 33.1 11.5 2.6Urea (mg/dl) 49 63 147.0 162.0 71.0 61.0Creatinine (mg/dl) 0.7 0.8 1.8 4.7 3.8 3.1LDH (U/l) 911 817 956 793 837C3 (mg/dl)(75-140.00) 55.80 49.90 55.90pH 7.457 7.482 6.942PaCO2 (mmHg) 37.8 35.9

PaO2 (mmHg) 68.6 82.2

HCO3- (mmol/l) 26.9 25.6 4.6

Lactate (mmol/l) 0.9 12.7

been present from the beginning, and thatafter six weeks of antibiotic therapy and withno clinical or laboratory signs of active infec-tion, the image of an abscess cavity probablycorresponded to an already epithelializedsequelar cavity; (2) the serious clinical situa-tion of the patient would result in postopera-tive death.

Meanwhile, Candida parapsilosis was iso-lated from a blood culture taken on December21 2009 (one positive and two negative bloodsamples, susceptible to fluconazole, voricona-zole, amphotericin B and caspofungin), forwhich iv fluconazole was initiated as soon asthe result was known (January 2 2010). Serialblood cultures were no longer positive forMRSA after the first week of therapy.

Assuming that renal function would notrecover, the temporary hemodialysis catheter

was replaced in the nephrology unit by a per-manent tunneled catheter inserted through thelumen of the previous one. On the same day,several hours after the procedure, severe clin-ical worsening occurred: on the following daythe patient presented in septic shock and pro-found lactic acidosis (pH 6.942; cHCO3- 4.6mmol/l; anion gap 17.5 mmol/l; cLactate 12.7mmol/l), and was transferred to the intensivecare unit. Assisted ventilation was required,and iv vancomycin and piperacillin-tazobac-

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Figure 1. Endocapillary proliferation, with scattered PMNs associated with peripheral endocapillary deposits on the right (arrow) (HE, x400).

Figure 2. Prominent mesangial and peripheral deposits of C3 (subendothelial location – arrow) (anti-C3 immunofluorescence, x400).

tam antibiotic therapy were prescribed as wellas circulatory support with vasoactive amines,but the patient died three days later due tomultiorgan failure. Serratia marcescens (sus-ceptible to piperacillin-tazobactam) was laterisolated from blood cultures obtained duringthis period, and two other blood culturesdated December 30 2009 and January 5 2010were positive for C. parapsilosis, although thisresult was known only after the patient’sdeath. Her family did not authorize necropsy.

DISCUSSION

In developed countries, IE is a rare disease,with an incidence of 3-10 cases/100,000 popu-lation per year. A higher prevalence has beenobserved in the elderly(1). While rheumaticheart disease remains the predominant riskfactor in developing countries, in developedcountries newer predisposing factors have aris-en, such as valve prostheses, degenerativevalve sclerosis and intravenous drug abuse (4),

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Figure 3. Cellular crescent (arrow) associated with endocapillary proliferation (PAS, x400).

and even esthetic procedures such as bodypiercing have been implicated in the develop-ment of IE in individuals with or without pre-vious heart disease. The incidence of HCAIEis increasing, representing up to 30% of totalcases (4), which are mostly related to invasivemaneuvers, such as intravenous catheters,hyperalimentation lines, pacemakers, anddialysis access, with a consequent high risk ofbacteremia. Aseptic measures during theseprocedures are therefore very important (4).

Changes in the conditions associated withIE have altered the frequency of the etiologi-cal microorganisms, with the incidence ofstreptococcal IE decreasing and that ofstaphylococcal IE increasing(1). In fact,HCAIE, besides being associated with olderage, diabetes, renal impairment and heart fail-ure, has also been associated with MRSA andEnterococcus(1). In a smaller proportion ofcases Candida (4%) and Gram-negative bacil-li (5%) may be the agents responsible forHCAIE. Mortality and morbidity remain unac-ceptably high and recent health care exposurehas been identified as an independent predic-tor of mortality (1).

Prosthetic valve IE represents 10-30%

cases of IE in most developed countries (5). Therisk of early-onset IE is greater for mechanicalheart valves, but later becomes similar formechanical devices and bioprostheses (5).Staphylococcus aureus and coagulase-negativeStaphylococcus are now the most commoncause of prosthetic valve endocarditis and areassociated with a poor prognosis (5). Prostheticvalve endocarditis is associated with highmortality despite diagnostic and therapeuticimprovements. Early prosthetic valve endo-carditis (first eight weeks after surgery) usual-ly presents with a more acute clinical picturethan late prosthetic valve endocarditis (morethan one year after surgery) (6), but these con-siderations can be modified in HCAIE.

Unexplained fever in a patient with a pros-thetic valve should prompt immediate andcareful evaluation for prosthetic valve endo-carditis. Frequently, new or changing mur-murs and congestive heart failure are detect-ed. Blood cultures (only a small percentage ofpatients with no previous antibiotic therapywill have sterile blood cultures) and echocar-diograms (preferably transesophageal) are ofcrucial importance in diagnosis(4, 5, 7). Serialechocardiograms throughout the clinical course

are of utmost importance for evaluation of theseverity of IE and for the detection of valvedestruction by abscesses, a not uncommonoccurrence in SA valve infections. Real-timepolymerase chain reaction of bacterial rDNAfrom surgically removed heart valves is arecent diagnostic method that is especiallyuseful in patients with culture-negative IE.

IE’s clinical course may present with vari-ous complications, as was well illustrated inour patient’s case. Heart failure is the mostfrequent severe complication of IE (4) and con-gestive heart failure and neurological eventshave the strongest influence on the clinicalcourse and prognosis of IE(4). Congestive heartfailure is usually due to infection-inducedvalve damage, and aortic valve infection ismore frequently associated with congestiveheart failure than is mitral valve infection.Cavities visualized on ultrasonography are asign of perivalvular abscess formation (7).

Systemic emboli are among the most com-mon clinical sequelae of IE, occurring in up to40 per cent of patients, and can often predatethe diagnosis. There is a trend towards a high-er risk of subsequent systemic embolism inpatients with a vegetation >10 mm.Neurological manifestations occur in 30-40%of patients, embolic stroke being the most

common and clinically important (8). They aremore frequent when IE is caused by SA andare associated with increased mortality.

Other neurological complications includeintracranial hemorrhage resulting either fromhemorrhage into an infarct or from rupture ofa mycotic aneurysm, cerebral abscesses,purulent meningitis, severe headaches,seizures and encephalopathy. Rapid treatmentwith antibiotics is of major importance, sincethe rate of embolic neurological eventsdecreases significantly after it is begun (8).Despite antibiotics having been initiated assoon as a diagnosis of IE was confirmed, ourpatient still suffered a neurological eventwhich affected prognosis as well as clinicaland surgical options.

Renal events in IE include renal infarctsdue to septic embolism occluding interlobulararteries and arterioles (particularly in SA endo-carditis), renal cortical necrosis, antibiotic-induced interstitial nephritis, renal abscessesand glomerulonephritis that may or may not besecondary to immunoglobulin and complementdeposition in mesangial and subendotheliallocations (3, 9). Renal biopsy specimens mayreveal focal and segmental or diffuse prolifera-tive lesions, often associated with infiltratingcells, typically monocytes/macrophages, and

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Figure 4. Transesophageal echocardiogram: biological aortic prosthesis (a) and adjacent epithelialized aortic abscess cavity (b)

sometimes a neutrophilic exudate. Crescentsare often associated with proliferative lesions.Rarely, rapidly progressive exudative glomeru-lonephritis develops, leading to end-stage renalfailure unresponsive to antibiotic therapy.Immunostaining reveals granular C3 deposition,which is often but not always accompanied byIgG or IgM (3). Persistent circulating immunecomplexes and C3 depletion, despite antibiotictreatment, have been shown to indicate the fail-ure of therapy and a high probability of persist-ent infection and glomerulonephritis (3).

Renal insufficiency as a result of immunecomplex-mediated glomerulonephritis occursin less than 15% of cases. Patients with IEdue to MRSA are significantly more likely tohave complicating renal insufficiency and toexperience persistent bacteremia than thosewith IE due to MSSA. Patients may developendocarditis-related glomerulonephritisdespite appropriate antibiotic therapy, and thedevelopment of renal failure may be delayeduntil several days after antibiotic therapy isinitiated. Patients presenting with advancedrenal failure usually have a poor outcome (3).

Rarer complications are vertebral osteomye-litis, acute septic arthritis, and metastaticabscesses in the spleen and soft tissues.Additionally, all measures associated with hos-pital treatment of IE can by themselves causetheir own complications (hospital infections)(9).

Mortality from prosthetic valve IE isextremely high (20-30% of cases)(6). Ourpatient clearly illustrates several risk factorsassociated with increased mortality during theclinical course of IE: congestive heart failure,renal failure, neurological events, old age andcomorbidities (previous heart disease and pul-monary hypertension), as well as exposure inan overcrowded infirmary.

Treatment of prosthetic valve IE relies on acombination of prolonged antimicrobial therapyand, in about half of patients, valve surgery(abscess drainage and/or removal of endovascu-lar prosthetic material for treatment of uncon-trolled sepsis)(4, 5). Recommended antimicrobialtherapy for prosthetic valve IE due to MRSA isan association of vancomycin plus rifampin for6-8 weeks plus gentamicin for two weeks (or an

alternative drug in gentamicin-resistant SA) (6).By contrast, vancomycin has worse results inthe treatment of endocarditis due to MSSA thanbeta-lactam antibiotics.

When assessing treatment outcomes, it isimportant to bear in mind the recent emergenceof multiple MRSA phenotypes with reducedsusceptibility to glycopeptides. Minimuminhibitory concentrations (MICs) of vancomycinfor MRSA in these cases can be higher thanusual (1-2 μg/ml). These strains are van-comycin-intermediate SA (VISA) with MICsbetween 4-8 μg/ml, heterogeneous VISA(hVISA), which contains a subpopulation ofcells with reduced susceptibility to vancomycin(MICs ≥4 μg/ml), and vancomycin-resistant SA(VRSA) (MICs ≥16 μg/ml). Also to be consid-ered is the occurrence of MRSA in a communi-ty setting with silent acquisition in patientswho were previously in a healthcare environ-ment, or household contacts, as well as trulycommunity-acquired MRSA with Panton-Valentine leukocidin genes(10). At our hospitalwe have no facilities to investigate this issue.

Not all novel pharmaceutical moleculessuch as lisostaphin, quinupristin-dalfopristin,linezolid, daptomycin and tigecycline are validproven options for left-sided acute MRSAendocarditis, although they exhibit comparablein vitro activity against MRSA. The oxazolidi-none linezolid appeared to be effective in sev-eral recent studies (10).

Since a considerable proportion of prosthet-ic valve IE patients may require surgery, carefulplanning and individualization of interventiontiming is essential. The optimal time to performsurgery is before severe hemodynamic disabili-ty or spread of the infection to perivalvular tis-sue have occurred. The most frequent indica-tions for surgery are heart failure, uncontrolledinfection and prevention of embolic events(9).The risks associated with surgery are higher forpatients with prosthetic valve endocarditis thanfor those with native valve IE, but the recom-mendations for surgery are essentially the samefor both forms of endocarditis.

It has long been known that if not con-traindicated for any reason, combined medicaland surgical treatment significantly improves618

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outcome, with mortality rates of SA prostheticvalve endocarditis diminishing from 70% to25% of cases (8). Some authors consider thatSA prosthetic valve IE alone may be an indica-tion for valve replacement surgery. However, asPaterick et al. (9) clearly advise, surgery is notindicated if complications or comorbid condi-tions suggest that the possibility of recovery isremote.

Unfortunately, in the case of our patient wewere initially only able to diagnose nativemitral valve endocarditis, and the patient alsopresented complications that despite being tosome extent reasons to perform surgery, werealso a contraindication, due to their severity.The neurological event that our patient suf-fered affected the planning of surgical treat-ment. When central nervous system complica-tions occur, timing for surgical treatment can-not be precisely defined. It should usually beperformed after two or four weeks, respective-ly, if an embolic or hemorrhagic event hasoccurred, and ideally in the absence of heartfailure (8). Anuria due to immune complexacute glomerulonephritis also made immedi-ate surgery impossible.

During the clinical evolution our patientpresented with two hospital infections: (1)positive blood culture for Candida parapsilo-sis on the 39th day of hospitalization after aprolonged course of several parenteric antibi-otics, but not known until the 56th day, atwhich time iv fluconazole was initiated; (2)septic shock due to septicemia from Serratiamarcescens infection, probably occurring afterthe insertion of a tunnelized hemodialysiscatheter through a previous one. S. marcescenswas isolated in blood cultures taken two daysbefore the patient died. S. marcescens, a Gram-negative Enterobacteriacea, is an opportunisticpathogen in humans, responsible for hospitaloutbreaks, particularly in the ICU. Serratia isresponsible for about 2% of nosocomial bac-teremias and infections of the lower respiratorytract, urinary tract, surgical wounds, and skinand soft tissues. S. marcescens infectionsshould be treated with an aminoglycoside plusan anti-Pseudomonas beta-lactam.

In conclusion, we considered several pos-

sible mechanisms of MRSA HCAIE occur-rence in our patient: (1) acute IE due to MRSAis usually HCAIE acquired inside hospitalsand nursing and residential homes, wherethere is frequent use of antibiotics such asmacrolides, cephalosporins, quinolones, andto some extent aminoglycosides (10); (2) intra-venous procedures utilized several times inthe environment of our hospital (emergencyward and infirmary); (3) in general, inade-quate ward or unit staff, or staff training, over-crowding of patients, lack of isolation facili-ties, frequent relocation of patients and staff,and poor attention to infection control proce-dures increase the risk of nosocomial infec-tions. It is also suggested that some MRSAinfections presenting from the community aresometimes associated with silent acquisitionafter patients have been in an inpatient envi-ronment for more than five days within thepast year (10); (4) although very rare, there is arisk of SA infection and even of death after redblood cell transfusion (as reported by the FDAand other sources) (11).

The antibiotic association utilized at thebeginning was decided based on the possibilityof prosthetic valve HCAIE. Unfortunately thefirst diagnosis was an isolated infection of anative valve, with several acute and seriouscomplications occurring sequentially, thatmade it impossible to proceed with prostheticvalve surgery. This case is presented to illus-trate how the evolution of a case of acute IE dueto MRSA can be difficult to control and to treat.

Address for reprints:

António Murinelloe-mail: amurinello@gmail.comor amurinello@iol.ptor antoniomurinello@yahoo.comAddress: Avenida Engº. António AzevedoCoutinho, lote 8 R/C Dto.2750-644 CascaisPortugal 619

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Recebido para publicação: ????????????? • Aceite para publicação: ?????????Received for publication: ????????????? • Accepted for publication: ?????????

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3. Chadban SJ, Atkins RC. Management of infection-associatedglomerulonephritis. In: Therapy in Nephrology & Hypertension –A Companion to Brenner & Rector’s “The Kidney”, Berl T,Himmelpark J, Mitch WE, Murphy B, Salant DJ, Yu ASL, eds.Philadelphia: Saunders Elsevier, 2008: 140-150

4. Habib G. Infective endocarditis: What’s new? European Societyof Cardiology (ESC) Guidelines 2009 on the prevention, diagnosisand treatment of infective endocarditis. Presse Med 2010; 39:704-709

5. Nataloni M, Pergolini M, Rescigno G, Mocchegiani R. Prostheticvalve endocarditis. J Cardiovasc Med POST AUTHOR CORREC-TIONS, 11 February 2010, doi: 10.2459/JCM.0b013e328336ec9a

6. San Martin J, Sarriá C, de las Cuevas C, Duarte J, Gamallo C.Relevance of clinical presentation and period of diagnosis in pros-thetic valve endocarditis. J Heart Valve Dis 2010; 19: 131-138

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