A view on Bartonella quintana endocarditis--confirming the molecular diagnosis by specific fluorescence in situ hybridization

Culture-negative endocarditis is a frequent problem in cardiology, especially if caused by fastidious organisms. Among these, the diagnostic tools for the detection of Bartonella quintana are still unsatisfactory. In a culture-negative case of suspected endocarditis undergoing aortic valve replacement, polymerase chain reaction amplification and sequencing of the 16S rRNA gene indicated B. quintana infection. To develop a new diagnostic tool, independent from culture and amplification techniques, we designed and optimized an oligonucleotide fluorescence in situ hybridization (FISH) probe specific for B. quintana and suitable for FISH. FISH succeeded in simultaneous visualization and identification of vital microorganisms directly within the aortic valve tissue and in fast and univocal diagnosis of B. quintana endocarditis.     

Culture and antibiotic susceptibility of Bartonella quintana in human erythrocytes

Bartonella quintana, the agent of trench fever, has recently been implicated in various diseases, in particular, bacteremia and endocarditis in homeless people. The host cell of Bartonella spp. is believed to be the erythrocyte, and in the present study we demonstrate that B. quintana can be cultured in vitro in human erythrocytes. The bacteria were found to be intraerythrocytic by laser confocal microscopy with Bartonella species-specific monoclonal antibodies. Infections with B. quintana decreased the life span of erythrocytes in culture from 8.6 to 4.8 days. In the culture system we found that most of the antibiotics that we tested (doxycycline, fluoroquinolone compounds, and beta-lactams) were not bactericidal. Gentamicin was bactericidal at 4 micro g/ml, as was rifampin, but to a lesser extent. At this concentration, gentamicin has been shown to enter erythrocytes slowly and to reach a peak level of 0.26 micro g/ml after 24 h. At 0.26 micro g/ml, however, we found that gentamicin was not able to kill extracellular B. quintana, even after 96 h of incubation. We hypothesize that erythrocytes may be a reservoir for B. quintana and that the bactericidal activity of gentamicin that we observed occurs mainly when the bacteria emerge from the erythrocytes and are found extracellularly. It would appear that gentamicin should be administered for at least 5 days to cure patients infected with B. quintana.     

Fusobacterium necrophorum endocarditis Case report and review of the literature

Fusobacterium necrophorum is a gram-negative anaerobic bacillus that can cause serious systemic infections typically in previously healthy young adults. Lemierre's syndrome, also known as post-anginal sepsis or necrobacillosis, is the infection most usually associated with F. necrophorum. However, F. necrophorum is also a very rare cause of anaerobic endocarditis. Mortality and rates of thromboembolism are high with F. necrophorum endocarditis. In this article, we describe a case of F. necrophorum native valve infective endocarditis. The patient was treated with penicillin plus clindamycin followed by penicillin alone for 6 weeks resulting in complete resolution of infection.     

Granulicatella elegans native valve infective endocarditis: case report and review

Granulicatella elegans is a fastidious organism that is rarely implicated as a cause of infective endocarditis. Here, we describe a patient with mitral valve prolapse who developed G. elegans endocarditis. The organism was isolated from blood cultures and the patient had mitral valvuloplasty and repair, and completed a course of 6 weeks of intravenous antibiotics with no sequela.     

Culture-negative infectious endocarditis caused by Bartonella spp.: 2 case reports and a review of the literature

Bartonella spp. are rare pathogens in humans and were recently recognized as important causative agents of culture-negative endocarditis. Here, we describe the 1st 2 documented cases of culture-negative endocarditis due to Bartonella henselae and Bartonella quintana encountered in a single hospital in Germany. Infection of the heart valve tissue was detected by broad-range polymerase chain reaction (PCR) and further confirmed by serologic testing. In particular, acute B. henselae infection with an impressive bacterial colonization of the infected cardiac valve was illustrated by transmission electron microscopy. B. henselae was further characterized by PCR assays targeting genotype-specific regions. Disease progression was initially monitored over the entire infection episode through inflammatory markers. In addition, a short overview of published detailed cases of Bartonella endocarditis in Europe within the last 7 years is given.     

Neurologic Complaints in a Patient with Infective Endocarditis

Background

Infectious intracranial aneurysms constitute a small subgroup of all intracranial aneurysms, but are an important cause of neurologic complaints in patients with infective endocarditis. Objective: To describe a potentially fatal cause of neurologic complaints in patients with endocarditis. Case Report: We report a case of a 33-year-old woman with Streptococcus sanguinis endocarditis and several neurologic complaints including right arm numbness, confusion, and occasional word-finding difficulty that were found to be secondary to infectious intracranial aneurysm.

Conclusion

Early consideration of intracranial infectious aneurysm in patients with infective endocarditis and neurologic symptoms is critical. Therapeutic intervention is often effective, and risk of aneurysm rupture is high.     

GLOMERULAR LESIONS OF SUBACUTE BACTERIAL ENDOCARDITIS

1. In most cases of chronic or subacute bacterial endocarditis due to the endocarditis coccus (Streptococcus viridans), there exists a distinctive pathological lesion in some of the glomeruli due to bacterial emboli. 2. The salient features of the pathological picture are first, the involvement of one or more loops of a variable number of glomeruli; secondly, the absence of any visible disease in the uninvolved glomeruli and in the uninvolved portions of affected glomeruli; and thirdly, the association in most of the bacterial cases of all the various stages of the glomerular process often seen in a single microscopical section. 3. The lesion does not occur in cases of acute endocarditis, and up to the present time it has been absent in cases of subacute bacterial endocarditis due to organisms other than the endocarditis coccus. 4. In a group of cases having vegetations that are typical of those in the active stage of subacute endocarditis (except that they are free from bacteria and healing or healed), the healed stage of this distinctive glomerular lesion is present, although it is less extensive than in the active bacterial cases. 5. These cases, therefore, are most probably examples of subacute bacterial endocarditis due originally to the endocarditis coccus, but in which the endocardial vegetations have become free from bacteria rather early in their course and are now healing or healed, as claimed by Harbitz and Libman. 6. During the active bacterial stage of the disease, if the glomerular lesions are not too numerous, the only symptoms produced will be an almost constant hematuria, usually demonstrable only microscopically. If the glomerular lesions are very numerous, symptoms resembling those of subacute hemorrhagic nephritis may occur and may even cause a fatal issue. If the glomerular lesions are very numerous but not sufficient to cause death, and the cardiac lesion should go on to healing, a contracted kidney, secondary to the glomerular lesion, may subsequently ensue and produce the typical symptoms and death. In such a case, the finding of the healed or healing lesion of subacute bacterial endocarditis will be accidental.     

Nontuberculous mycobacterial blood stream and cardiac infections in patients without HIV infection

Nontuberculous mycobacteria rarely cause bacteremia in HIV-negative patients. We describe 16 cases, including the first Mycobacterium neoaurum endocarditis. Nine cases were line related. Most patients were immunocompromised secondary to hematologic malignancy or other comorbid conditions. Amikacin had the most reliable in vitro activity. Combination therapy was frequently used. Mortality was 25%.     

A first Japanese case of Bartonella henselae-induced endocarditis diagnosed by prolonged culture of a specimen from the excised valve

Bartonella henselae, the causative agent of cat scratch disease, is increasingly recognized as a cause of culture-negative endocarditis. This report describes the first Japanese case, which was diagnosed after a prolonged culture of the excised aortic valve. High IgG and IgM titers to B. henselae pointed to a subacute course of the disease.     

Meningitis and subgaleal, subdural, epidural empyema due to Pasteurella multocida

Pasteurella is a Gram-negative coccobacillus found in 70-90% of oral cavities of cats, and as well, is isolated from the digestive systems of dogs, rats, rabbits, monkeys, and other animals. Pasteurella multocida has been known to cause infections in humans, the most familiar being soft tissue infection after animal bites. However, this organism may affect a variety of systems, causing serious disease. Pasteurella multocida can cause septic arthritis, osteomyelitis, pneumonia, endocarditis, meningitis, and septicemia. We report a case of bacterial meningitis, subgaleal, subdural, and epidural empyema due to Pasteurella multocida by a rabbit licking that resulted in neurological complications and a prolonged recovery period.     

In vitro Bartonella quintana infection modulates the programmed cell death and inflammatory reaction of endothelial cells

Bartonella quintana is an epicellular bacterium, which in vivo as well as in vitro, invades endothelial cells and develops within them inducing proliferative effects that play a pivotal role in neovascular manifestation of this disease. We investigated the effect of live Bartonella quintana and its LPS on apoptosis and inflammatory response in HUVEC-C, an endothelial cell line. The kinetics of the programmed cell death of Bartonella quintana-infected HUVEC-C showed a peculiar course. Even if early during infection apoptosis reached a peak after 6 h, later on apoptosis was inhibited. Such apoptosis inhibition was not observed during Bartonella quintana lipopolysaccharide treatment because LPS-stimulated HUVEC-C did progress to cell death. Evaluation of multiple cell signal transduction pathways revealed an overexpression of Apaf 1 and caspase 8 in HUVEC-C after 2 h of infection, and of bcl-2 starting from 10 h post Bartonella quintana infection. Moreover, Bartonella quintana and its LPS showed a different effect on the activation of genes involved in inflammatory response as revealed by molecular analysis of host cells. Bartonella quintana appears to be able to inhibit programmed cell death, inducing intracellular signals leading to survival and proliferation through the bcl-2 gene, despite the early increase of inflammatory status induced in endothelial cells. This mechanism, together with a poor endotoxin ability to stimulate strong inflammatory response, could contribute to the capability of the bacteria to persist intracellularly, causing chronic disease and producing neovascular manifestations.     

Erysipelothrix bacteremia without endocarditis: rare event or under-reported occurrence?

A patient presented with inflamed hands and Erysipelothrix rhusiopathiae bacteremia. Because a high incidence of endocarditis has been reported with this organism, a transesophageal echocardiogram was obtained, which was normal. Treatment with oral moxifloxacin resolved all manifestations of illness. The association between E. rhusiopathiae bacteremia and endocarditis may be spurious.     

Subacute bacterial endocarditis: making the diagnosis

The presentation of endocarditis varies from patient to patient, making it a difficult infection to diagnose correctly. While some patients will develop symptoms acutely over days, it may take weeks or months for symptoms to develop as in the case of subacute bacterial endocarditis.     

An unusual cluster of Acremonium kiliense fungaemias in a haematopoietic cell transplantation unit

The genus Acremonium (formerly known as Cephalosporium) is a large polyphyletic fungal genus that comprises approximately 150 phylogenetically distant species, commonly isolated from the environment. Clinical cases concern mostly superficial infections after traumatic inoculation, but there are reports of opportunistic invasive infections in immunocompromised patients. Acremonium kiliense has been described as a cause of mycetoma, keratitis, endophthalmitis, endocarditis, and continuous ambulatory peritoneal dialysis–associated peritonitis. We describe an unusual cluster of possible catheter-related bloodstream infections due to this pathogen in patients who underwent haematopoietic cell transplantation.     

Infectious endocarditis: An update for emergency clinicians

Introduction

Infectious endocarditis (IE) is a potentially deadly disease without therapy and can cause a wide number of findings and symptoms, often resembling a flu-like illness, which makes diagnosis difficult.

Native-valve endocarditis caused by Staphylococcus lugdunensis

Coagulase-negative staphylococci cause about 5% of native-valve endocarditis. Staphylococcus lugdunensis, a recently-described species of coagulase-negative staphylococci, has been reported to cause destructive native-valve endocarditis with a high mortality. We report four consecutive cases of definite Staphylococcus lugdunensis native- valve endocarditis by the Duke criteria over a 4-year period. All patients required urgent aortic valve replacement 1-5 days after admission, and recovered. An intriguing, aspect in the presentation of these patients was a history of vasectomy and inguinal skin breaks in the immediate period preceding the occurrence of endocarditis.      

猴株五日热巴尔通体药敏及生化特性研究

目的 了解猴株五日热巴尔通体的生化特性和药物敏感性, 为进一步研究五日热巴尔通体的耐药机制奠定基础。方法 采用E test法, 检测1株五日热ATCC参考株及10株五日热巴尔通体猴分离株的生化特性及对14种抗生素的最低抑菌浓度(MIC)。结果 H15SC对利福平高度耐药(MIC256), 其余菌株敏感;H98SC对克林霉素耐药, 其余菌株敏感;除S13外, 其余10株菌株对丁胺卡那霉素、多粘菌素MICs值较高;全部菌株对阿奇霉素、头孢他啶、环丙沙星、庆大霉素、红霉素、妥布霉素、氯霉素、强力霉素、苄星青霉素敏感。结论 首次发现巴尔通体菌株对利福平高度耐药, 需要进一步了解其耐药机制, 减少不合理用药, 预防利福平耐药在人分离株中发生。     

Infective endocarditis and osteomyelitis caused by Cellulomonas: a case report and review of the literature

Cellulomonas spp. are often believed to be of low virulence and have never been reported as a pathogen causing human disease before. We report the first case of endocarditis caused by Cellulomonas and complicated with osteomyelitis of the lumbar spine in a 78-year-old woman. General weakness and aggravated lower back pain followed by sudden-onset of fever and chills were the major presentation. The diagnosis of infective endocarditis in this case was definitely using the Duke criteria. The magnetic resonance imaging of the lumbar spine revealed infective spondylodisciitis at an early stage. After a full course of antibiotics treatment, the patient's fever subsided but her lower back pain persisted. A slow clinical response to appropriate antimicrobial agents was characteristic of Gram-positive bacillary endocarditis.