Review

Authors: Mansoor Khaledi, Fatemeh Sameni, Hamed Afkhami...

Infective endocarditis (IE) is a severe disease that is still associated with high mortality despite recent advances in diagnosis and treatment. HACEK organisms (Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae) are gram-negative bacteria that are part of the normal flora of the mouth and upper respiratory tract in humans. These organisms cause a wide range of infections, of which IE is one of the most notable. In order to control and prevent endocarditis caused by HACEK, measures such as oral hygiene and the use of prophylactic drugs should be used for people at risk, including people with underlying heart disease and people with artificial valves. This review is a summary of the main aspects of IE focusing on HACEK organisms.

Topics: Eikenella corrodens; Endocarditis; Endocarditis, Bacterial; Haemophilus; Heart Diseases; Humans

PubMed: 35986339
DOI: 10.1186/s13019-022-01932-5

Review

Authors: Matthieu Revest, Gérald Egmann, Vincent Cattoir...

The HACEK group of bacteria - Haemophilus parainfluenzae, Aggregatibacter spp. (A. actinomycetemcomitans, A. aphrophilus, A. paraphrophilus, and A. segnis), Cardiobacterium spp. (C. hominis, C. valvarum), Eikenella corrodens, and Kingella spp. (K. kingae, K. denitrificans) - are fastidious gram-negative bacteria, part of the normal microbiota of oral and upper respiratory tract in humans. Although their pathogenicity is limited, they are responsible for 1-3% of all infective endocarditis. HACEK endocarditis mostly affect patients with underlying heart disease or prosthetic valves, and are characterized by an insidious course, with a mean diagnosis delay of 1 month (Haemophilus spp.) to 3 months (Aggregatibacter and Cardiobacterium spp.). The advent of continuously monitored blood culture systems with enriched media has erased the need for extended incubation for the diagnosis of HACEK endocarditis. Medical treatment relies on third-generation cephalosporin, with a favorable outcome in 80-90% of cases, with or without cardiac surgery.

Topics: Cephalosporins; Endocarditis, Bacterial; Gram-Negative Bacteria; Humans; Risk Factors

PubMed: 26953488
DOI: 10.1586/14787210.2016.1164032

Authors: Andrés Blanco-Carrión

Bacterial endocarditis (BE) is a disease resulting from the association of morphological alterations of the heart and bacteraemia originating from different sources that at times can be indiscernible (infectious endocarditis). It is classified on the basis of the morphological alteration involved, depending on the clinical manifestations and course of illness, which varies according to the causative microorganism and host conditions (for example, it is characteristic in I.V. drug users). The most common microorganisms involved are: Streptococcus viridans (55%), Staphylococcus aureus (30%), Enterococcus (6%) and HACEK bacteria (corresponding to the initials: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella), although on occasions it can also be caused by fungi. The oral microbiological flora plays a very important role in the aetiopathogenesis of BE, given that the condition may be of oral or dental origin. This paper will deal with the prevention of said bacteraemia. Prophylaxis will be undertaken using amoxicillin or clindamycin according to action protocols, with special emphasis placed on oral hygiene in patients with structural defects of the heart.

Topics: Amoxicillin; Anti-Bacterial Agents; Antibiotic Prophylaxis; Bacteremia; Clindamycin; Dental Care for Chronically Ill; Endocarditis, Bacterial; Humans; Oral Surgical Procedures

PubMed: 15580136
DOI: No ID Found

Review

Authors: Ryohei Ono, Izumi Kitagawa, Yoshio Kobayashi...

BACKGROUND

is a member of the HACEK group, which causes infective endocarditis (IE) but is rarely associated with other infections. It is difficult to biologically identify because of its slow growth in culture. However, the clinical features of IE remain unclear.

METHOD

We searched the PubMed database for all articles of IE published between January 2000 and July 2022.

RESULTS

The major clinical features of 44 previously reported cases of IE were as follows: the median age was 59 years, of which 36 were men; the initial presenting symptoms were chest discomfort (30 %), followed by fever (27 %), night sweats (20 %), fatigability (18 %), weight loss (16 %), and dyspnea (16 %). Almost half of the patients were febrile upon admission. The major predisposing factors were postsurgical valve treatment (57 %), dental treatment or caries (20 %), and congenital valve abnormality (5 %). The median time to identify in the blood culture was 4 days, but the longest time was 42 days. The most commonly infected valve was the aortic valve, and the most common complication was systemic embolism. Surgical treatment was performed in 23 (52 %) patients. The most frequent initial treatment regimen was cephem antibiotics, with a median treatment duration of 6 weeks. The overall mortality and recovery rates of IE were 9 % and 91 %, respectively.

CONCLUSION

If infection is confirmed, physicians should check for the presence of vegetations of the heart valves and understand these characteristics.

PubMed: 38510192
DOI: 10.1016/j.ahjo.2022.100248

Authors: Tina Bennett Bonavent, Xiaohui Chen Nielsen, Kjeld Skødebjerg Kristensen...

INTRODUCTION

and are well known, though rare, etiologic agents of infective endocarditis. Cardiac devices are increasingly implanted.

CASE REPORTS

Two cases of infective episodes in pacemaker (PM) treated patients with respectively and are presented. In one case blood-culture bottles yielded growth of at two episodes with two years apart. At the second episode a vegetation was recognized at the PM lead and the PM device and lead was removed. In the case, echocardiography revealed a bicuspid aortic valve with severe regurgitation and a more than 1 cm sized vegetation.

CONCLUSION

The cases illustrate the diversity in disease severity by Careful follow up has to be performed in order not to overlook a relatively silent relapsing infection.

PubMed: 28077974
DOI: 10.2174/1874285801610010183

Authors: Nao Suzuki, Yoshio Nakano, Masahiro Yoneda...

OBJECTIVES

It has been suggested that smoking affects the oral microbiome, but its effects on sites other than the subgingival microbiome remain unclear. This study investigated the composition of the salivary and tongue bacterial communities of smokers and nonsmokers in periodontally healthy adults.

METHODS

The study population included 50 healthy adults. The bacterial composition of resting saliva and the tongue coating was identified through barcoded pyrosequencing analysis of the 16S rRNA gene. The Brinkman index (BI) was used to calculate lifetime exposure to smoking. The richness and diversity of the microbiome were evaluated using the t-test. Differences in the proportions of bacterial genera between smokers and nonsmokers were evaluated using the Mann-Whitney U test. The quantitative relationship between the proportions of genera and the BI was evaluated using Pearson's correlation analysis.

RESULTS

The richness and diversity of the oral microbiome differed significantly between saliva and the tongue but not between smokers and nonsmokers. The saliva samples from smokers were enriched with the genera Treponema and Selenomonas. The tongue samples from smokers were enriched with the genera Dialister and Atopobium. The genus Cardiobacterium in saliva, and the genus Granulicatella on the tongue, were negatively correlated with BI values. On the other hand, the genera Treponema, Oribacterium, Dialister, Filifactor, Veillonella, and Selenomonas in saliva and Dialister, Bifidobacterium, Megasphaera, Mitsuokella, and Cryptobacterium on the tongue were positively correlated with BI values.

CONCLUSIONS

The saliva and tongue microbial profiles of smokers and nonsmokers differed in periodontally healthy adults. The genera associated with periodontitis and oral malodor accounted for high proportions in saliva and on the tongue of smokers without periodontitis and were positively correlated with lifetime exposure to smoking. The tongue might be a reservoir of pathogens associated with oral disease in smokers.

Topics: Adult; Bacteria; Cigarette Smoking; Humans; Microbiota; Periodontitis; RNA, Ribosomal, 16S; Tongue

PubMed: 34505401
DOI: 10.1002/cre2.489

Review

Authors: Keith P Mintz, David R Danforth, Teresa Ruiz...

Infective endocarditis (IE), a disease of the endocardial surface of the heart, is usually of bacterial origin and disproportionally affects individuals with underlying structural heart disease. Although IE is typically associated with Gram-positive bacteria, a minority of cases are caused by a group of Gram-negative species referred to as the HACEK group. These species, classically associated with the oral cavity, consist of bacteria from the genera (excluding ), , , , and . , a bacterium of the Pasteurellaceae family, is classically associated with Aggressive Periodontitis and is also concomitant with the chronic form of the disease. Bacterial colonization of the oral cavity serves as a reservoir for infection at distal body sites via hematological spreading. adheres to and causes disease at multiple physiologic niches using a diverse array of bacterial cell surface structures, which include both fimbrial and nonfimbrial adhesins. The nonfimbrial adhesin EmaA (extracellular matrix binding protein adhesin A), which displays sequence heterogeneity dependent on the serotype of the bacterium, has been identified as a virulence determinant in the initiation of IE. In this chapter, we will discuss the known biochemical, molecular, and structural aspects of this protein, including its interactions with extracellular matrix components and how this multifunctional adhesin may contribute to the pathogenicity of A. actinomycetemcomitans.

Topics: Animals; Humans; Adhesins, Bacterial; Aggregatibacter actinomycetemcomitans; Bacterial Adhesion; Endocarditis, Bacterial; Type V Secretion Systems

PubMed: 38392837
DOI: 10.3390/pathogens13020099

Review

Authors: Eitaro Okumura, Junya Tsurukiri, Hiroshi Yamanaka...

Acute infectious endocarditis (IE) is a complex disease that presents as a serious clinical condition associated with a high mortality rate, especially due to intracranial hemorrhaging (ICH). The most common causative organism is Staphylococcus aureus. We herein report a patient with ICH following subacute IE with a positive blood culture for Cardiobacterium hominis. A review of the existing literature revealed that acute IE associated with Cardiobacterium has been reported to cause ICH in only seven previous cases. Prolonged culture-specific antibiotic therapy along with extended surveillance of blood culture is therefore essential for timely intervention.

Topics: Adult; Anti-Bacterial Agents; Cardiobacterium; Endocarditis, Bacterial; Female; Gram-Negative Bacterial Infections; Humans; Intracranial Hemorrhages; Male; Middle Aged

PubMed: 30626838
DOI: 10.2169/internalmedicine.2111-18

Review

Authors: Nathalie Victoria Zacarías Mendoza, Norma Nicole Gamarra Valverde, Víctor Justo Robles Velarde...

Infective endocarditis is a serious disease associated with high mortality despite recent advances in diagnosis and treatment. is a fastidious Gram-negative member of the HACEK organisms ( spp., , , , and ). is associated with dental infections but has also been implicated in cases of infective endocarditis. We highlight the importance of a high index of suspicion in symptomatic patients with an initial negative blood culture, particularly in high-risk groups such as patients with congenital valve disease and prosthetic valve. The knowledge of this rare entity may lead to early diagnosis and appropriate management. We review the main characteristics of endocarditis reported in the medical literature.

PubMed: 38046225
DOI: 10.47487/apcyccv.v4i3.306

Authors: Takahiko Fukuchi, Hitoshi Sugawara

Topics: Cardiobacterium; Endocarditis; Endocarditis, Bacterial; Humans; Intracranial Hemorrhages

PubMed: 31484906
DOI: 10.2169/internalmedicine.3077-19