Infectious endocarditis due to Gemella morbillorum found by splenic infarction--a case report

A 64-year-old man with prostate cancer and bone metastasis admitted for nausea, left abdominal pain showed no abnormal, and fever, abdominal ultrasound or chest X-ray findings. Despite antibiotics, left abdominal pain persisted for several days. Abdominal computed tomography (CT), showed splenic infarction. Transesophageal echocardiography suggested infectious endocarditis (IE) as a possible infarction cause, and roth spots were found on the retina. Gemella morbillorum was detected from blood culture. IE commonly causes Fever of Unknown Origin found by infarction. G. morbillorum, an anaerobic gram-positive, viridans group streptococci, is indigenous to the oropharynx, upper respiratory, urogenital, and gastrointestinal tracts, and is thought to have weak toxicity and pathogenicity in the body.     

Inoculum effect

The inoculum effect (IE) is a laboratory phenomenon that is described as a significant increase in the minimal inhibitory concentration of an antibiotic when the number of organisms inoculated is increased. The IE generally occurs with beta-lactam antibiotics in relation to beta-lactamase-producing bacteria. An IE occurs with the first- and second-generation cephalosporins against Staphylococcus aureus and less often with the quinolones, beta-lactam-resistant penicillins, cefoxitin, and aminoglycosides. An IE occurs with the penicillins against the Enterobacteriaceae and Pseudomonas species, and a variable IE occurs with cephalosporins; however, no IE occurs with aminoglycosides, quinolones, imipenem, and chloramphenicol against these organisms. An IE occurs with beta-lactam antibiotics against Haemophilus influenzae and with the penicillins and the cephalosporins against penicillinase-producing Neisseria gonorrhoeae and Branhamella catarrhalis. An IE occurs with the penicillins and cephalosporins against the Bacteroides fragilis group; no IE occurs with cefoxitin and imipenem. Although certain antibiotics exhibit an IE, they are still capable of eradicating infections when administered appropriately. Thus, the clinical significance of this laboratory phenomenon has yet to be elucidated.     

Infective endocarditis caused by lactobacillus

Lactobacillus (LB) is a gram-positive rod-shaped bacterium that inhabits the oral cavity, gastrointestinal tract, vagina and nasal cavity. Although LB plays a role in the prevention of infections caused by pathogenic bacteria, it causes some critical infectious diseases such as infective endocarditis (IE). IE due to LB is rare; however, early diagnosis and early treatment are important because of its high mortality rate. We report the onset of IE after otologic treatment in a heavy drinker of alcohol, the second case of IE due to LB in Japan.     

感染性心内膜炎730例病原菌构成及药敏分析

目的 分析感染性心内膜炎（infective endocarditis,IE）患者病原菌构成及药敏结果,为本地区经验性抗感染方案的制订提供依据.方法 对2006年1月至2012年9月在广东省人民医院住院的730例IE患者的血培养结果资料进行回顾性分析.结果 （1）血培养阳性率为28.6％,病原菌构成：革兰阳性球菌157例（75.1％）,革兰阳性杆菌15例（7.2％）,革兰阴性杆菌18例（8.6％）,假丝酵母菌18例（8.6％）;最常见细菌为链球菌（40.7％）、葡萄球菌（23.4％）、肠球菌（10.5％）.（2）药敏：在革兰阳性球菌中,链球菌、肠球菌对氨苄西林和青霉素的敏感性比较,差异无统计学意义（94.9％ vs.90.6％,P=0.25; 77.8％ vs.84.2％,P=0.53）;但葡萄球菌对氨苄西林的敏感性显著高于青霉素,差异有统计学意义（58.8％ vs.7.0％,P＜0.001）.革兰阳性菌对糖肽类药物普遍敏感,氨基糖甙类对葡萄球菌及革兰阴性杆菌都有较高的抗菌活性.结论 广东省人民医院IE患者病原菌血培养阳性率低,病原菌以革兰阳性球菌多见;病原菌未明时,宜选择氨苄西林或糖肽类联合氨基糖苷类抗生素作为本区域经验性抗感染方案.     

The rationale for the new infective endocarditis guidelines

Given the terrible consequences of infectious endocarditis (IE), it has become a time-honored strategy to use antibiotics as prophylaxis against IE for invasive procedures associated with bacteremia with endocarditis-causing organisms. The evidence supporting this approach has come predominantly from animal models of endocarditis or observational human studies. Prompted by the desire to realistically assess the evidence base for a health policy with global implications and against the backdrop of increasing microbial resistance to antibiotics, a careful review of all available data regarding the effectiveness of prophylaxis against IE was performed. This reanalysis prompted a new set of recommendations for IE prevention, published in 2007 by the American Heart Association, which represented a marked divergence from 50 years of prior publications. The rationale and underpinning evidence for the new recommendations are reviewed here, with an eye to the gaps in the available evidence and the need for future research.     

Infective endocarditis as a mid‐term complication after transcatheter aortic valve implantation

Few cases of infective endocarditis (IE) as a complication of percutaneous transcatheter aortic valve implantation (TAVI) have been reported. Here, we present a case of IE caused by Streptococcus viridans that occurred 6 months after TAVI with the corevalve revalving system. The patient was successfully treated with antibiotics and was asymptomatic during the 2 years after IE. We also present a review of the literature, including 15 published cases of IE after TAVI. © 2014 Wiley Periodicals, Inc.     

感染性心内膜炎的血培养阳性与阴性临床意义

目的　明确血培养阳性与阴性的感染性心内膜炎 (IE)之间在临床特征和预后方面的异同。方法　对63例IE患者 ,根据血培养结果分成阳性组 (N =15 )和阴性组 (N =48) ,比较临床特征和预后。结果　 41例 ( 65 .1% )经超声心动图检出有赘生物 ,两组病人的赘生物检出率、基础心脏病和感染部位一致 ,从入院到确诊时间无显著差异。两组病人入院前有使用抗生素的比率分别为 3 3 .3 %和 85 .4% (P <0 .0 1)。血培养阳性组白细胞计数较阴性组高 (P <0 .0 1) ,因而更易出现发热和脓肿并发症 (P <0 .0 5 ) ,而血培养阴性组更多出现心瓣膜破裂或穿孔 ,严重心衰 ,更多病人施行了心脏换瓣手术 (P <0 .0 5 ) ,但两组病人预后无统计学差异。结论　由于血培养前抗生素的广泛使用 ,IE血培养阳性率明显下降 ,超声心动图检查有助于血培养阴性IE的早期诊断。血培养阴性IE后果更为严重 ,早期诊断和及时的手术换瓣治疗可以改善预后     

Enterococcal Endocarditis: Can We Win the War?

Treatment of enterococcal infections has long been recognized as an important clinical challenge, particularly in the setting of infective endocarditis (IE). Furthermore, the increase prevalence of isolates exhibiting multidrug resistance (MDR) to traditional anti-enterococcal antibiotics such as ampicillin, vancomycin and aminoglycosides (high-level resistance) poses immense therapeutic dilemmas in hospitals around the world. Unlike IE caused by most isolates of Enterococcus faecalis, which still retain susceptibility to ampicillin and vancomycin, the emergence and dissemination of a hospital-associated genetic clade of multidrug resistant Enterococcus faecium, markedly limits the therapeutic options. The best treatment of IE MDR enterococcal endocarditis is unknown and the paucity of antibiotics with bactericidal activity against these organisms is a cause of serious concern. Although it appears that we are winning the war against E. faecalis, the battle rages on against isolates of multidrug-resistant E. faecium.     

Comparative in vitro activities of third-generation cephalosporins

The in vitro susceptibilities of 823 clinical isolates to eight third-generation cephalosporin and cephalosporinlike antibiotics were studied. All eight antibiotics were more active and had broader spectrums of activity against gram-negative bacilli and anaerobes than older derivatives; however, they were less active against gram-positive cocci. Cefotaxime sodium, cefmenoxime hydrochloride, ceftriaxone disodium, and ceftizoxime sodium had similar activities. Cefoperazone sodium was more active than those drugs against Pseudomonas aeruginosa but less active against Enterobacteriaceae and Acinetobacter. Ceftazidime pentahydrate was more active against P aeruginosa but less active against gram-positive cocci. Moxalactam disodium was more active against some Enterobacteriaceae, Pseudomonas maltophilia, and Bacteroides fragilis but less active against gram-positive cocci. Thienamycin formamidide monohydrate had the broadest spectrum of activity and was the only antibiotic active against Streptococcus faecalis; the only resistant species were P maltophilia and Pseudomonas cepacia.     

Increase of Fungal Endocarditis in Children

AbstractBackground: Infective endocarditis (IE) is a rare and feared infection that mainly occurs in patients with underlying cardiac disease or altered function of the immune system. Recent epidemiological data on both sepsis and nosocomial infections indicate a rise in gram–negative bacterial and fungal infection, particularly in patients requiring critical care support. This study sought to characterize the change in the spectrum of IE encountered in a single pediatric tertiary care center during the last 18 years, to evaluate emergence of fungal IE and to identify contributing factors.Patients and Methods: Review of all cases of IE diagnosed between January 1986 and August 2003 at a single university children’s hospital. Patients were distributed between two equal time periods and compared according to the era of IE diagnosis.Results: In 43 patients, 44 episodes of IE were identified with most cases occurring in children with congenital or acquired heart disease. The annual number of diagnosed cases fluctuated during the study (mean 2.4 cases/year). Blood or specimen cultures were positive in 34 cases (77%) with gram–positive organisms most frequently observed (n = 20, 44.4%). Fungal IE cases (n = 9, 20%) occurred preferentially during the second period (p < 0.03), and were more common in children with noncardiac diseases (p = 0.023). Factors associated with fungal IE were the use of broad–spectrum antibiotics (p < 0.001) and the presence of an infected central venous catheter (p = 0.01). Overall mortality did not differ between the two eras.Conclusion: The incidence of fungal IE seems to have significantly increased in more recent years. Use of broadspectrum antibiotics for prolonged time or/and central venous catheters were identified as predisposing factors to fungal infective endocarditis.     

Endocarditis: epidemiology, diagnosis and treatment

The current incidence of infective endocarditis (IE) is estimated as seven cases per 100,000 population per year and continues to increase. The prognosis is significantly influenced by proper diagnosis and adequate therapy. In cases with unconfirmed IE, besides careful clinical examination, transesophageal echocardiography is the imaging technique of choice. Culture-negative endocarditis requires either termination of antimicrobial treatment initiated without microbiological test results and reevaluation of blood samples or serological/molecular biological techniques to identify the causative organism. Antimicrobial therapy should established only after quantitative sensitivity tests of antibiotics, including evaluation of the minimal bactericidal concentrations (MBC) of established combinations of antibiotics. Concomitant kidney involvement, a significant impairment of the hepatic function or the combination therapy with oto- and/or nephrotoxic antibiotics, requires drug monitoring. Large (> 10 mm) vegetations attached to the mitral valve are linked with a high incidence of thromboembolic complications. In most of these cases, the indication for surgical intervention is given, especially if the MBC of the optimal combination of antibiotics is high (> 2 micrograms/ml). In the first three weeks after primary manifestation of signs and symptoms of IE, an index embolism is frequently followed by recurrences. If vegetations can still be demonstrated by echocardiography after an embolic event, surgical intervention should seriously be considered. Cerebral embolic events are no contraindication for surgery with use of the heart-lung machine, as long as cerebral bleeding has been excluded by cranial computed tomography immediately preoperatively and the operation is performed before a significant disturbance of the blood-brain barrier (< 72 hours) has manifested. A significant prognostic improvement has also been demonstrated for patients with early surgical intervention, after their clinical course was complicated by myocardial failure due to acute valve incompetence, acute renal failure, mitral kissing vegetations in primary aortic valve IE, and in patients with sepsis persisting for more than 48 hours despite adequate antimicrobial therapy.     

Current diagnosis of infective endocarditis

An analysis was made of 91 cases of infective endocarditis (IE) with regard to causative organisms and their sensitivities to various antibiotics, the clinical features of the disease, the laboratory test results and other items were important in establishing a diagnosis of IE. The number of cases of IE has shown a tendency to increase in recent years, particularly in the number of elderly patients, and the ratio of total cases consisting of prosthetic valve endocarditis (PVE) has shown a sharp increase. The most common causative organism is still Streptococcus viridans, but there has been an increase in the incidence of IE due to benzyl-penicillin-resistant strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis and other fastidious organisms. The percentage of underlying diseases represented by combined valvular diseases has been increasing, while the primary known cause of the infection of IE was dental treatments. A positive value for CRP, an accelerated value for ESR, leukocytosis, anemia, a decrease in serum Fe, a positive value for RA-T, were all parameters which showed a high correlation with IE, and these should be useful in establishing the diagnosis of IE. The use of cardioechography to detect cardiac vegetation is important in relation to establishing the diagnosis and prognosis of IE, and the evaluation of the therapeutic results.     

Survey of prophylaxis and management of infective endocarditis in patients with congenital heart disease: Japanese nationwide survey.

Guidelines for the prevention and management of infective endocarditis (IE) in children with congenital heart disease (CHD) have not been established, so the aim of this study was to clarify the incidence, practical prevention and management of IE in patients with CHD in Japan through a nationwide survey. A written questionnaire was sent to members of the Japanese Society of Pediatric Cardiology and Cardiac Surgery and information was obtained from 236 cardiologists in 228 institutions. Four hundred and eight patients with IE were hospitalized during 1997 to 2001 (1/173 admissions with CHD including those hospitalized for cardiac catheterization or surgery). Prevention of IE for CHD was undertaken by 92% of cardiologists, usually oral penicillins (73%) and less frequently cephems (18%) were prescribed. The Duke criteria were used as clinical criteria by 38%. Blood culture was performed once only by 40%. Penicillins and aminoglycosides (38%) were frequently administered for management of culture-negative IE. There were variations in the dose and duration of antibiotics for prevention and management of IE. It appears that the prevalence of IE in CHD is rising and the nationwide survey revealed more variations in practical prevention and management of IE in patients with CHD than expected. The results should be helpful in making future guidelines for management of IE in CHD.     

Infective endocarditis in patients with kidney failure: Chronic dialysis and kidney transplant

Physicians who treat patients with infective endocarditis (IE) are encountering a growing number of dialysis and kidney transplant patients. Both groups have 30 to 100 times higher risk of IE, with 1-year mortalities of 40% to 60%. The predominant organisms causing IE are gram positive, with 60% to 80% of cases due to Staphylococcus aureus, and another 10% to 20% of cases due to coagulase-negative staphylococci. Renal transplant patients may develop fungal IE, but this risk is primarily in the first 3 months after transplant. In addition to blood cultures, transesophageal echocardiogram is the most useful diagnostic examination for IE in these patients. Initial antibiotic therapy, pending final culture and antibiotic susceptibility results, should provide coverage against the most common organisms and allow for the potential of either methicillin or vancomycinresistant species. Removal of infected hemodialysis access devices and at least 4 to 6 weeks of intravenous antibiotics are recommended. Antibiotic prophylaxis against IE has been recommended for all dialysis and renal transplant patients, but this strategy is controversial and unproven.     

Staphylococcus aureus, platelets, and the heart

Infective endocarditis (IE) caused by Staphylococcus aureus is serious, burgeoning frequency, and growing increasingly resistant to antibiotics. S. aureus IE is associated with high morbidity and mortality rates in nosocomial and community-acquired settings. S. aureus is the most common, most virulent IE etiologic pathogen. S. aureus IE pathogenesis depends upon complex interaction among the pathogen, platelets, plasma proteins, and vascular endothelial cells. S. aureus coordinates the expression of key virulence factors required for the specific pathogenic phases of IE. Platelets, now appear to play an important role in antimicrobial host defense against S. aureus IE and other endovascular infections. Platelet microbicidal proteins are believed to significantly contribute to the antimicrobial properties of platelets; however, abnormal disposition of native or prosthetic cardiac valves is an important risk factor in S. aureus IE establishment and severity. Thus, the need to define the molecular mechanisms of S. aureus pathogenesis and host defense against IE is urgent. Understanding these mechanisms will yield new approaches for the prevention and treatment of such life-threatening cardiovascular infections due to S. aureus.     

Infective endocarditis in the 1980s: Experience at a heart hospital

Three hundred episodes of infective endocarditis (IE) in 287 patients were studied from October 1978 to August 1986. The patients were in the age range of 0.2–78 (mean 30.76±16.06) years; 185 (68%) occurred in male patients. The etiologic agents were: Streptococci viridans group (93), enterococci (21), streptococci D group, nonenterococci (19), other streptococci (14), Staphylococcus aureus (59), Staphylococcus epidermidis (14), gram-negative bacteria (16), other gram-positive bacteria (16), fungi (4). Etiologic agents were not isolated in 52 (negative cultures). Valvular heart diseases occurred in 231 episodes, congenital heart diseases in 37, other heart diseases in 6. Sixty-nine occurred in patients with prosthetic heart valves. In 69 there was no previous heart disease. Surgical treatment was performed in 102 episodes (37 with prosthetic valve IE and 65 with native valve IE); 22 patients (21%) died, 12 with prosthetic valve and 10 with native valve IE. The in-hospital mortality (medical and surgical patients) was 26% (78 patients). Long-term follow-up of 206 patients up to 7.1 (mean 2.13±1.68) years revealed that 26 patients died. Thus, IE remains a disease with high mortality and is fatal to a third of the patients, in spite of the progress in therapeutic methods. Its morbidity and mortality continues beyond the microbiological cure.     

Causative organism influences clinical profile and outcome of infective endocarditis in pediatric patients and adults with congenital heart disease.

BACKGROUND: Studies on microorganisms in a large cohort of patients with congenital heart disease (CHD) and infective endocarditis (IE) are rare. Using a nationwide survey, the relationship between causative microorganisms and clinical profiles in patients with CHD and IE was investigated. METHODS AND RESULTS: Data from 188 patients with CHD (pediatric patients (n=113), mean age, 6.2+/-4.9 years; adult patients (n=75), mean age 28.4+/-13.4 years) and IE from 60 institutions were analyzed. Causative microorganisms were Streptococcus species (94:50.0%), Staphylococcus species (68:36.2%), Haemophilus species (9:4.8%), Candida (5:2.7%), Pseudomonas species (4:2.1%) and other unclassified microorganisms (8:4.3%). Staphylococcal IE was observed significantly higher in perioperative IE (11/16), in cyanotic patients (32/73) and patients younger than 1 year old (11/16). Streptococcal IE was observed significantly higher in acyanotic patients (64/109) and patients aged 16 years or older (48/75). Total mortality was 20/188 (10.6%) and was high for candidial (2/5; 40%) and pseudomonal IE (2/4; 50%). Mortality was highly associated with younger age, especially infants (5/16), and methicillin-resistant staphylococcal IE (6/15). CONCLUSIONS: The causative microorganisms are significantly related to the clinical profile and outcome in patients with IE and CHD. These results form the basis for selecting appropriate antibiotics for prevention and management.     

Postantibiotic suppression of bacterial growth

Persistent suppression of bacterial growth following exposure of both gram-positive and gram-negative bacteria to numerous antimicrobial agents was studied. The persistent, or postantibiotic, effect was quantitated by periodic counts of colony-forming units after removal of the drug by washing, dilution, or inactivation with penicillinase. Although a postantibiotic effect was observed with all drugs studied, there were marked differences among drugs in their postantibiotic effects on certain organisms. With gram-positive organisms, concentrations of beta-lactam antibiotics near the minimal inhibitory concentration produced persistent effects lasting 1-3 hr. With gram-negative organisms much higher concentrations were required to elicit a postantibiotic effect. Inhibitors of protein and RNA synthesis produced the longest persistent suppression of growth, which was of comparable duration in gram-positive and gram-negative bacteria. Only a short persistent effect of gentamicin was observed with Staphylococcus aureus and Escherichia coli, but a postantibiotic effect lasting 1.6-2.6 hr was observed with Pseudomonas aeruginosa. The duration of the postantibiotic effect was related linearly to concentration of drug and duration of exposure up to a point of maximal response. Persistent effects following exposure to antibiotics were also demonstrated in 90% human serum.     

Microbiology and risk factors for gram-positive Cocci bacteremia in biliary infections

BackgroundThe rapid antibiotics treatment targeted to a specific pathogen can improve clinical outcomes of septicemia. We aimed to evaluate the clinical characteristics and outcomes of biliary septicemia caused by cholangitis or cholecystitis according to causative organisms.MethodsWe performed a retrospective cohort study in 151 patients diagnosed with cholangitis or cholecystitis with bacterial septicemia from January 2013 to December 2015. All patients showed clinical evidence of biliary tract infection and had blood isolates that demonstrated septicemia.ResultsGram-negative, gram-positive, and both types of bacteria caused 84.1% (127/151), 13.2% (20/151), and 2.6% (4/151) episodes of septicemia, respectively. The most common infecting organisms were Escherichia coli among gram-negative bacteria and Enterococcus species (Enterococcus casseliflavus and Enterococcus faecalis) among gram-positive bacteria. There were no differences in mortality, re-admission rate, and need for emergency decompression procedures between the gram-positive and gram-negative septicemia groups. In univariate analysis, previous gastrectomy history was associated with gram-positive bacteremia. Multivariate analysis also showed that previous gastrectomy history was strongly associated with gram-positive septicemia (Odds ratio = 5.47, 95% CI: 1.19–25.23; P = 0.029).ConclusionsPrevious gastrectomy history was related to biliary septicemia induced by gram-positive organisms. This information would aid the choice of empirical antibiotics.