Lugdunensis Bacteremia Research Articles

Characteristics and outcomes in adult patients with Staphylococcus lugdunensis bacteremia compared to patients with Staphylococcus epidermidis and Staphylococcus aureus bacteremia: a retrospective study in a 16-year period at the university hospital, Japan

BackgroundStaphyococcus lugudnensis (S. lugdunensis) is one of coagulase-negative Staphylococcus species with a potential to cause invasive infections. Few studies have evaluated the characteristics and outcomes of patients with S. lugdunensis bacteremia (SLB) compared with those of patients with Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) bacteremia.MethodsWe performed a single-center retrospective case–control study of patients aged ≥ 18 who had SLB with at least two sets of positive blood cultures at the Kyoto University Hospital, Japan, from January 2005 to June 2022. Patients who had S. epidermidis bacteremia (SEB) with at least two sets of positive blood cultures and those who had S. aureus bacteremia (SAB) with at least one set of positive blood cultures were randomly selected in a 1:5:5 (SLB:SEB:SAB) ratio.ResultsA total of 22 patients with SLB, 110 patients with SEB, and 110 patients with SAB were included. The proportions of infective endocarditis (IE) and metastatic infections were statistically higher in the SLB group than in the SEB group (14% vs. 2%, p < 0.01 and 18% vs. 5%, p 0.02, respectively) and were not significantly different between the SLB and SAB groups (14% vs. 5%, p 0.16 and 18% vs. 16%, p 0.78, respectively). The seven-day mortality was higher in the SLB group than in the SEB group (9% vs. 1%, p 0.02) and similar between the SLB and SAB groups (9% vs. 7%, p 0.77).ConclusionsThe clinical course and outcome of SLB were worse than those of SEB and similar to those of SAB. Appropriate evaluation and treatment for SAB may be warranted in patients with SLB.

Staphylococcus lugdunensis bacteremia: clinical implications of single set positive blood cultures

Staphylococcus lugdunensis is exceptionally virulent among the coagulase-negative Staphylococcus species, but the clinical significance of single-positive bacteremia of S. lugdunensis remains uncertain. We investigated S. lugdunensis bacteremia cases over 10 years. Of the 49 cases included, 12 had multiple-positive blood cultures and 37 had single-positive blood cultures. Antimicrobial therapy was given to over 80% of both groups, whereas the duration of therapy was significantly longer in the multiple-positive group. The overall 30-day and 90-day mortality rates were 13.3% and 18.2%, and 36.7% and 18.2% for single and multiple-positive patients, respectively. Five single-positive patients without therapy did not have severe infection, presumed source of infection, or culture positivity within 20 hours, but all defervesced within 2 days and were alive at 30 days. While the clinical spectrum of single-positive S. lugdunensis bacteremia is broad, antimicrobial therapy may be withheld without adverse clinical consequences in a subset of low-risk patients.

Fatal septic embolism due to Staphylococcus lugdunensis-induced bacteremia.

Staphylococcus lugdunensis infective endocarditis (IE) is very rare in children. A female neonote presented with fever on the 29th postoperative day after undergoing a modified Norwood procedure (right ventricular-pulmonary artery [RV-PA] conduit). Blood cultures were positive for S. lugdunensis. Echocardiography did not demonstrate vegetation. Therefore, we made a diagnosis of catheter-related bacteremia instead of IE. Cultures were negative 3days after treatment initiation with intravenous vancomycin. One month after discharge, she developed acute hypoxia and could not be revived because of obstruction of RV-PA conduit with large vegetation. Even in S. lugdunensis bacteremia without IE, surgical treatment should be considered early.

298. Multicenter retrospective cohort study of the clinical significance of Staphylococcus lugdunensis isolated from a single blood culture set

Background Staphylococcus lugdunensis is a coagulase negative Staphylococcus (CoNS) species with the potential to cause aggressive infection. Guidance surrounding S. lugdunensis bacteremia (SLB) is lacking, especially in the case of a single positive set of blood cultures.MethodsWe performed a multicenter, retrospective observational cohort review of adult patients with SLB from at least one blood culture set within the University of Maryland Medical System from November 2015-November 2019. Objectives were to (1) describe baseline characteristics, (2) compare available criteria for evaluating clinical significance, and (3) evaluate the clinical outcomes among patients with SLB in 1 vs ≥2 positive blood culture sets. Descriptive statistics with Chi-squared and Mann-Whitney U tests were carried out.ResultsThere were 5,548 CoNS-positive blood culture sets, 49 (0.88%) with S. lugdunensis comprising 36 adult patients (24 with 1 positive set and 12 with ≥2 positive sets). Patients with ≥2 positive sets were more likely to be on hemodialysis (HD) (p=0.029) and to have an HD catheter present (p=0.10) (Table 1). Thirty-five of the 36 patients fulfilled at least one of the following: systemic inflammatory response syndrome (SIRS), Souvenir criteria, or clinical criteria (infectious focus on imaging and/or second positive culture site) (Table 2). Twenty-eight (78%) patients were treated with antimicrobial therapy and/or central line removal. SIRS criteria were met more often among patients with 1 positive set (p=0.05). Patients with ≥2 positive sets were more often treated with antibiotics for longer than 2 weeks (p=0.02). The mean time of positive cultures to discharge was 11 days and was longer for patients with only one set of positive blood cultures (13 vs. 6 days), although this difference was not statistically significant (p=0.29) (Table 3). ConclusionSLB was rare and occurred more frequently as a single set of positive blood cultures. Though limited by sample size, this study found similar patient characteristics, clinical significance and outcomes between patients with one set and those with ≥2 sets of blood cultures positive for S. lugdunensis. Given the potential severity of SLB, it seems prudent to treat S. lugdunensis in a single blood culture, but larger studies are needed.Disclosures All Authors: No reported disclosures

Multicenter retrospective cohort study of the clinical significance of Staphylococcus lugdunensis isolated from a single blood culture set

BackgroundStaphylococcus lugdunensis is a coagulase negative Staphylococcus species and frequent human skin commensal with the potential for aggressive infection. Guidance surrounding S. lugdunensis bacteremia (SLB) from a single set of blood cultures is lacking. MethodsA multicenter, retrospective cohort of patients with SLB from at least one blood culture set within the University of Maryland Medical System from 2015 to 2019 is presented. Objectives are to describe baseline characteristics, compare the clinical status and treatment course, and to evaluate the clinical outcomes among patients with SLB in single versus multiple sets. ResultsThirty-six patients were included, 24 with one set of blood cultures positive for S lugdunensis and 12 with multiple sets. Baseline characteristics were similar between the groups, though patients with SLB in multiple sets were more commonly on hemodialysis (P = 0.029). Central lines were the most common source (17%). Most (97%) fulfilled systemic inflammatory response syndrome or Souvenir criteria, had an infectious focus on imaging, or had a second positive culture site. Most (78%) were treated as clinically significant. Patients with multiple positive sets were more commonly treated with antibiotics for >2 weeks (P = 0.02). ConclusionsSLB was rare and occurred more frequently as a single set of positive cultures. Patient characteristics and clinical courses were similar between single and multiple set groups. Given the potential severity of S. lugdunensis bacteremia it seems prudent to treat S. lugdunensis in a single blood culture as true bacteremia, pending larger studies and guidelines.

Staphylococcus lugdunensis: The “Lyon Heart” Pathogen

Abstract Staphylococcus lugdunensis is a coagulase-negative Staphylococcus capable of causing infective endocarditis on native as well as prosthetic valves and implanted cardiac devices. It causes acute disease clinically indistinguishable from that caused by Staphylococcus aureus. Bacteremic infections with S. lugdunensis have a high incidence of associated infective endocarditis. Many S. lugdunensis isolates are exquisitely sensitive to penicillin G. Endocarditis caused by S. lugdunensis frequently requires surgical intervention and has a high mortality rate. Case 1: A 48-year-old woman with mitral valve prolapse, S. lugdunensis bacteremia and mitral valve endocarditis. She underwent emergent mitral valve replacement and completed treatment with intravenous nafcillin. Case 2: A 31-year-old woman with spontaneous S. lugdunensis bacteremia and tricuspid valve endocarditis. She was successfully treated medically with 6 weeks of intravenous nafcillin. Case 3: A 44-year-old man with S. lugdunensis endocarditis on congenital bicuspid aortic valve with severe aortic insufficiency. He underwent emergent aortic valve replacement and successfully completed 6 weeks of intravenous nafcillin. Case 4: A 37-year-old woman with spontaneous S. lugdunensis bacteremia and native aortic valve endocarditis. She was successfully treated medically with 6 weeks of intravenous vancomycin. Case 5: A 57-year-old woman with hemodialysis catheter-related S. lugdunensis bacteremia and native mitral valve endocarditis. She was successfully treated medically with 6 weeks of intravenous cefazolin. Staphylococcus lugdunensis is a unique coagulase-negative Staphylococcus first identified in Lyon, France, the modern name for the Roman city of Lugdunum, ergo the organism's name. Since its identification, S. lugdunensis has been described as a “Lion among coagulase-negative staphylococci” and as “a dangerous wolf in sheep's clothing” because of the tendency of clinicians to initially discount positive blood cultures with “coagulase-negative staphylococci” as probable skin contaminants and thereby delay appropriate antimicrobial therapy. We report 5 patients with S. lugdunensis endocarditis and review the adult literature for other reported cases.

The Occurrence of Infective Endocarditis With Staphylococcus lugdunensis Bacteremia: A Retrospective Cohort Study and Systematic Review

Summary Background Staphylococcus lugdunensis is a coagulase-negative staphylococcus with similar virulence characteristics as Staphylococcus aureus. Whether S. lugdunensis causes infective endocarditis (IE) in a similar proportion of cases as S. aureus (reported to be 12.6% in a definitive multicenter prospective study) is unclear. Methods We conducted a retrospective cohort study of adult patients with at least one blood culture positive for S. lugdunensis at our institution from January 2006 to December 2014. We examined microbiology data, ascertained disease severity and determined the proportion of patients with definite or possible IE based on the 2000 Modified Duke Criteria. Because coagulase-negative staphylococci were routinely identified to the species level at our institution from 2012 onwards, we determined the proportion of patients with definite or possible IE before and after implementation of routine speciation. We also compared our results with reported proportions of IE among patients with S. lugdunensis bacteremia (SLB) in other institutions by conducting a systematic review of the scientific literature. Nonparametric bootstrapping methods were performed to determine 95% confidence intervals (CI) for proportions of IE in patients with SLB. Results Seventy-four patients with SLB were identified, of whom 64% (47/74) had sepsis by SIRS criteria, and 18% (13/74) had severe illness by Pittsburgh bacteremia score (PBS). Kaplan–Meier survival analysis showed that one-year survival among patients with severe illness was worse than patients with non-severe illness (p = 0.02). Fifteen percent (11/74) of patients had definite or possible IE (95% CI 6.8–23.0%). The proportion of SLB patients with definite or possible IE was 15.8% (6/38, 95% CI 5.3–28.9%) prior to routine speciation and 13.9% (5/36, 95% CI 2.8–27.8%) after routine speciation (p = 0.71). Among patients with at least two positive blood cultures for S. lugdunensis , 25% (10/40, 95% CI 12.5–40.0%) had IE. Systematic review of the literature yielded eight relevant retrospective studies. Of studies that included patients with one or more positive blood cultures for S. lugdunensis , the proportion of IE ranged from 6.3% to 27.0%. Conclusion The proportion of definite or possible IE among patients with SLB is similar to the proportion of IE among patients with S. aureus bacteremia. The proportions of IE among patients with SLB at other institutions fall within the 95% CI yielded by bootstrapping. Our findings suggest that growth of S. lugdunensis in two separate blood cultures should prompt consideration of workup for IE.

The occurrence of infective endocarditis with Staphylococcus lugdunensis bacteremia: A retrospective cohort study and systematic review

Staphylococcus lugdunensis is a coagulase-negative staphylococcus with similar virulence characteristics as Staphylococcus aureus. Whether S. lugdunensis causes infective endocarditis (IE) in a similar proportion of cases as S. aureus (reported to be 12.6% in a definitive multicenter prospective study) is unclear. We conducted a retrospective cohort study of adult patients with at least one blood culture positive for S. lugdunensis at our institution from January 2006 to December 2014. We examined microbiology data, ascertained disease severity and determined the proportion of patients with definite or possible IE based on the 2000 Modified Duke Criteria. Because coagulase-negative staphylococci were routinely identified to the species level at our institution from 2012 onwards, we determined the proportion of patients with definite or possible IE before and after implementation of routine speciation. We also compared our results with reported proportions of IE among patients with S. lugdunensis bacteremia (SLB) in other institutions by conducting a systematic review of the scientific literature. Nonparametric bootstrapping methods were performed to determine 95% confidence intervals (CI) for proportions of IE in patients with SLB. Seventy-four patients with SLB were identified, of whom 64% (47/74) had sepsis by SIRS criteria, and 18% (13/74) had severe illness by Pittsburgh bacteremia score (PBS). Kaplan-Meier survival analysis showed that one-year survival among patients with severe illness was worse than patients with non-severe illness (p=0.02). Fifteen percent (11/74) of patients had definite or possible IE (95% CI 6.8-23.0%). The proportion of SLB patients with definite or possible IE was 15.8% (6/38, 95% CI 5.3-28.9%) prior to routine speciation and 13.9% (5/36, 95% CI 2.8-27.8%) after routine speciation (p=0.71). Among patients with at least two positive blood cultures for S. lugdunensis, 25% (10/40, 95% CI 12.5-40.0%) had IE. Systematic review of the literature yielded eight relevant retrospective studies. Of studies that included patients with one or more positive blood cultures for S. lugdunensis, the proportion of IE ranged from 6.3% to 27.0%. The proportion of definite or possible IE among patients with SLB is similar to the proportion of IE among patients with S. aureus bacteremia. The proportions of IE among patients with SLB at other institutions fall within the 95% CI yielded by bootstrapping. Our findings suggest that growth of S. lugdunensis in two separate blood cultures should prompt consideration of workup for IE.

The Long CoN(S): A Case of Staphylococcus lugdunensis Endocarditis With Cerebral and Coronary Embolism

Staphylococcus lugdunensis is a coagulase-negative staphylococcus, which in humans can cause virulent infections frequently attributable to Staphylococcus aureus including superficial skin/soft tissue infections, infective endocarditis, osteomyelitis and endophthalmitis. A 61-year-old male with history of recent fixation of C1-C2 neck fracture, presented with sudden onset of right-sided weakness and fever. Examination revealed dense hemiplegia with UMN facial palsy of right side, and a pan-systolic murmur in the mitral area, radiating to the axilla. He had an elevated troponin-I of 18.8 ng/mL with right bundle branch block on EKG. Echocardiogram revealed mobile vegetation on the anterior leaflet of the mitral valve with ejection fraction of 55% and no regional wall motion abnormality. He continued to have persistent high-grade fevers in spite of appropriate antibiotic therapy and blood cultures were persistently positive for S. lugdunensis for 5 days. He developed weakness of his left side after 2 weeks of hospital admission and MRA revealed left carotid dissection and complete occlusion of the right middle cerebral artery distal to the M1 segment which was embolic in nature. The frequency of S. lugdunensis infection is underappreciated and biofilm formation plays a major role in the pathogenesis. This is the first reported case of S. lugdunensis endocarditis complicated by NSTEMI from coronary embolism and simultaneous stroke from cerebral embolism. Due to the early, frequent and fatal complications from S. lugdunensis bacteremia, we might have to consider early surgical intervention in the absence of class I or IIa recommendation. J Med Cases. 2014;5(10):535-537 doi: http://dx.doi.org/10.14740/jmc1903w

Clinical experience and microbiologic characteristics of invasive Staphylococcus lugdunensis infection in a tertiary center in northern Taiwan

Staphylococcus lugdunensis is a coagulase-negative staphylococcus that cannot be ignored. This study is a comprehensive analysis of the clinical and microbiological characteristics of S. lugdunensis bacteremia and sterile site infection during hospitalization. This retrospective study included 48 patients with invasive S. lugdunensis infection. During the period of March 2002 to July 2012, they had been hospitalized in a tertiary center of northern Taiwan. Demographics, clinical characteristics, and risk factors of mortality were analyzed. All isolates were tested for antimicrobial susceptibility. We identified the staphylococcal cassette chromosome mec (SCCmec) gene for oxacillin nonsusceptible isolates. The incidence of S. lugdunensis in coagulase-negative staphylococci bacteremia was 0.87%. Forty-eight patients were enrolled: S. lugdunensis was present in 41 patients with bacteremia, in the ascites of three patients, in the synovial fluid of two patients, in the pleural effusion of one patient, and in the amniotic fluid of one patient. The three most common sources of infection were primary bacteremia (43.8%), catheter-related infection (18.8%), and vascular graft infection (12.5%). All-cause mortality during hospitalization was 20.8% (10/48). All deceased patients were bacteremic. Risk factors associated with in-hospital mortality included a Pittsburgh bacteremia score of 2 or greater, infective endocarditis, and end-stage renal disease. Ten (20.8%) isolates were resistant to oxacillin, and 8 isolates were classified as SCCmec type V. The clinical significance of S. lugdunensis should not be ignored, especially in patients with severe comorbidities. An aggressive search for endocarditis is strongly suggested in S. lugdunensis bacteremic cases.

The Long CoN(S): A Case of Staphylococcus lugdunensis Endocarditis With Cerebral and Coronary Embolism

Staphylococcus lugdunensis is a coagulase-negative staphylococcus, which in humans can cause virulent infections frequently attributable to Staphylococcus aureus including superficial skin/soft tissue infections, infective endocarditis, osteomyelitis and endophthalmitis. A 61-year-old male with history of recent fixation of C1-C2 neck fracture, presented with sudden onset of right-sided weakness and fever. Examination revealed dense hemiplegia with UMN facial palsy of right side, and a pan-systolic murmur in the mitral area, radiating to the axilla. He had an elevated troponin-I of 18.8 ng/mL with right bundle branch block on EKG. Echocardiogram revealed mobile vegetation on the anterior leaflet of the mitral valve with ejection fraction of 55% and no regional wall motion abnormality. He continued to have persistent high-grade fevers in spite of appropriate antibiotic therapy and blood cultures were persistently positive for S. lugdunensis for 5 days. He developed weakness of his left side after 2 weeks of hospital admission and MRA revealed left carotid dissection and complete occlusion of the right middle cerebral artery distal to the M1 segment which was embolic in nature. The frequency of S. lugdunensis infection is underappreciated and biofilm formation plays a major role in the pathogenesis. This is the first reported case of S. lugdunensis endocarditis complicated by NSTEMI from coronary embolism and simultaneous stroke from cerebral embolism. Due to the early, frequent and fatal complications from S. lugdunensis bacteremia, we might have to consider early surgical intervention in the absence of class I or IIa recommendation. J Med Cases. 2014;5(10):535-537 doi: http://dx.doi.org/10.14740/jmc1903w

Genotypes and phenotypes of Staphylococcus lugdunensis isolates recovered from bacteremia

Staphylococcus lugdunensis is a member of coagulase-negative staphylococci, which has the potential to cause serious infections, such as endocarditis, bone and joint infections, and septicemia. Differences in phenotypic/genotypic characterization may be linked to different diseases. Genotypes of 11 S. lugdunensis isolates from bacteremia were determined by pulsed field gel electrophoresis and accessory gene regulator (agr) typing. The SCCmec elements in two oxacillin-resistant isolates were sequenced. Phenotypes were tested by antimicrobial susceptibility testing, biofilm formation assessments, and virulence factor analysis (hemolytic and protease activities). Among the 11 isolates, six pulsotypes were found, and seven isolates belonged to two major pulsotypes. Two agr types (agr-1sl or agr-2sl) were found. The 11 isolates were susceptible to most antimicrobial agents tested. The SCCmec elements in two oxacillin-resistant isolates belonged to the SCCmec type V, but with additional ccrAB2 genes. The agr-2sl isolates (n = 7) displayed higher hemolytic and protease activities than the agr-1sl isolates. All isolates contained the icaA gene but with variable biofilm activities. The results suggest that protein might play an important part in S. lugdunensis biofilms, possibly through an ica-independent pathway. Of the 11 patients with S. lugdunensis bacteremia, one patient had a community-onset infection, and others had a hospital-acquired infection, which were mostly central venous catheter-related infections. The 11 S. lugdunensis bacteremia isolates displayed various genotypes and phenotypes. Two oxacillin-resistant isolates contained SCCmec type V and carried additional ccrAB2 genes. Correlation of genotypes and phenotypes with infections needs further studies.

P49 Evaluation of susceptibility to oxacillin and prognosis in patients with S. lugdunensis bacteremia

P49 Evaluation of susceptibility to oxacillin and prognosis in patients with S. lugdunensis bacteremia

English

Staphylococcus lugdunensis can cause virulent infections in immunosuppressed individuals. Here we describe a retrospective analysis of hemodialysis patients with Staphylococcus lugdunensis bacteremia admitted to a New York City hospital from January 2005 to December 2010. Six cases of S. lugdunensis bacteremia were identified. The majority had received antibiotic therapy for at least several weeks. None of them developed endocarditis or other serious complications. Four had their tunneled permanent dialysis catheters changed or removed. This pathogen is rare, but could often fail medical therapy alone and may require surgical intervention. This can be avoided with surveillance and early intervention in patients with high risk for infection. Key wordsStaphylococcus lugdunensis, Staphylococcus, bacteremia, infection, hemodialysis. International Journal of Microbiology Research ISSN: 0975-5276 & E-ISSN:0975-9174, Volume 4, Issue 2, 2012 Introduction S. lugdunensis is coagulase negative staphylococcus described by Fleurette et al in 1989 [1] but has been recently described as an emerging human pathogen [2]. While characterized as coagulase negative, because it does not produce coagulase, there is a membrane bound form of the enzyme in some isolates that can cause it to be misidentified as S. aureus [3]. Although it is considered a skin normal flora, it can cause virulent infections usually in immunosuppressed patients with implanted medical devices including bone replacements and cardiac valve replacements [4]. We report cases of S. lugdunensis bacteremia in hemodialysis patients with permanent tunneled cuffed catheters admitted to a New York City hospital. Methods At least one set of blood cultures were taken from each patient. Blood culture was collected in an adult Bac T/ALERT blood culture set, and upon receipt by the Microbiology laboratory, it was incubated in Bac T/ALERT instrument. Positive blood cultures were then Gram stained and sub cultured on TSA, MacConkey and Chocolate plated media. Next Day Positive cultures on the plate were identified using Walk Away MicroScan panels. Results Patients on hemodialysis who were infected with S. lugdunensis as a cause of bacteremia were identified. As shown in Table 1, all patients were African American and represented both genders equally. The average patient age was 53.8 years and the majority (83%) had hypertension among other co-morbidities. Half of the patients had their catheter placement at the NYC hospitals or its affiliates and 75% of patients had their hemodialysis treatment site elsewhere. The majority of patients were on dialysis for 2 years or less and none of the patients suffered any complications at time of discharge. Antibiotic sensitivities of S. lugdunensis cultured from infected patients are shown in Table 2. Isolates obtained from all patients were sensitive to ceftriaxone, clindamycin, oxacillin, rifampin, trimethoprim/sulfamethoxisole and vancomycin and resistant to penicillin. Of those tested, one of six patients was separately resistant to gentamycin and tetracycline. A brief summary of each of the patients infected with S. lugdunensis follows: Citation: Mallappallil M.C., et al. (2012) Staphylococcus lugdunensis bacteremia in hemodialysis patients. International Journal of Microbiology Research, ISSN: 0975-5276 & E-ISSN:0975-9174, Volume 4, Issue 2, pp.-178-181. Copyright: Copyright©2012 Mallappallil M.C., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Significance of Staphylococcus lugdunensis Bacteremia: Report of 28 Cases and Review of the Literature

Staphylococcus lugdunensis endocarditis has been associated with an aggressive course. The aim of this study was to determine factors associated with the development of endocarditis in patients with S. lugdunensis bacteremia. A retrospective analysis of all patients with S. lugdunensis bacteremia in three tertiary care centers in Switzerland was performed. Data regarding medical history, symptoms, and susceptibility of S. lugdunensis isolates were collected. Our results were reviewed in the context of the current literature. A total of 28 patients with S. lugdunensis bacteremia were identified. Of the 13 patients with endocarditis, all were community acquired. Cardiac surgery was performed in 85% of these patients; mortality was 23%, reflecting the aggressive course of this disease. In contrast, in the 15 patients without endocarditis, no complications associated with S. lugdunensis bacteremia were observed. In 73%, a probable source was identified in the form of a venous catheter or other foreign device. Only three of these episodes were community acquired. No difference was observed in susceptibility of the S. lugdunensis isolates to penicillin, which was 77% in endocarditis isolates, and 87% in isolates of bacteremia without endocarditis, respectively. S. lugdunensis bacteremia is associated with endocarditis in up to 50% of patients. Every patient with community-acquired S. lugdunensis bacteremia should be carefully examined for signs of endocarditis. Once S. lugdunensis endocarditis is diagnosed, close monitoring is essential and surgical treatment should be considered early. In the nosocomial setting, endocarditis is far less frequent, and S. lugdunensis bacteremia is usually associated with a catheter or other foreign materials.

Conservative management of a brain abscess in a patient with Staphylococcus lugdunensis endocarditis

Brain abscess is defined as a focal, intracerebral infection that begins as a localized area of cerebritis and develops into a collection of pus surrounded by a well-vascularized capsule. Microorganisms can gain access to the brain through several mechanisms, most commonly by direct extension of an adjacent suppurative focus (i.e. otitis media, mastoiditis, or sinusitis) or by direct penetration via an open cerebrospinal fluid leak (e.g. after cranial fracture or neurosurgical complication). Another mechanism of brain abscess formation is hematogenous bacterial spread from a distant focus of infection, such as endocarditis. Despite the presence of continuous bacteremia, brain abscess is an uncommon complication after bacterial endocarditis [1] (less than 5% of cases in most series). However, endocarditis due to Staphylococcus lugdunensis follows a more fulminant course, typically resulting in either cardiac complications or systemic emboli with metastatic foci of infection. Optimal handling of patients with bacterial infections of the central nervous system often requires surgical management; nonetheless, a subset of patients may be treated with appropriate antimicrobial therapy alone [2–4]. In this setting, the choice of antibiotic agents should be based on the results of susceptibility testing and the drug’s cerebrospinal fluid penetration. Here, we report a case of brain abscess in a patient with S. lugdunensis endocarditis involving a native bicuspid aortic valve. We also review the literature regarding the conservative management of brain abscesses in this clinical setting. A 49-year-old woman with an unremarkable medical history was admitted to our hospital with fever of 39°C, right-sided hemiparesis and aphasia. Computed tomography (CT) scan of the brain suggested an ischemic lesion of the left external capsule. S. lugdunensis was isolated from all four of the blood cultures taken upon admission. The organism was shown to be susceptible to all antibiotics tested. A transesophageal echocardiograph (TEE) confirmed the presence of large vegetations (12×4 mm) on the bicuspid aortic valve and subsequent regurgitation due to aortic valve destruction. The diagnosis of endocarditis due to S. lugdunensis involving a bicuspid aortic valve with severe aortic valve insufficiency and embolic septic cerebrovascular insult was established. Antibiotic therapy with flucloxacillin (2 g iv q4h), supplemented with gentamicin (80 mg iv tid) for the first 5 days, was started. Body temperature, neurological deficiencies and inflammatory laboratory values normalized rapidly and the patient remained hemodynamically stable. After 6 weeks of antibiotic therapy, TEE showed persistent aortic valve vegetation and an increased diastolic diameter of the left ventricle (EDVI: 63 ml/m). Valve replacement was subsequently recommended. A second CT scan (Fig. 1) performed during the pre-operative investigation revealed the presence of a small abscess (1 cm in diameter) at the level of the left insula. Given the size of the abscess, the lack of neurological symptoms and the known tendency toward development of metastatic lesion secondary to S. lugdunensis bacteremia, surgical abscess excision was deferred. Because of its optimal ability to penetrate the blood brain barrier, rifampin (600 mg orally bid) was added to the antibiotic regimen. Eur J Clin Microbiol Infect Dis (2006) 25:476–478 DOI 10.1007/s10096-006-0169-0