Native valve Bacillus cereus endocarditis in a non-intravenous-drug-abusing patient

Thrombus Tango: Hypercoagulable State With a Right Atrial Mass and Superimposed Persistent Bacteremia

Bacillus cereus is an uncommon nosocomial bacteria, typically dismissed as a contaminant. This case is a unique scenario in which B. cereus bacteremia persisted despite appropriate treatment. Further investigation revealed the presence of a right atrial thrombus believed to harbor a biofilm responsible for the sustained bacteremia. Clearance of the thrombus using the AngioVac system (AngioDynamics, Inc., Latham, NY) led to the resolution of blood cultures, and subsequently, the patient was discharged with a six-week course of intravenous (IV) antibiotics.

Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases

Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.

Complete Genome Sequences of 24 Strains of Bacillus cereus Isolated from Nosocomial Infection and Bacteremia Cases in Japan

Bacillus cereus is mainly associated with foodborne illness but sometimes causes nosocomial infections. We previously reported that B. cereus strains of a specific sequence type, ST1420, were associated with nosocomial infection. Here, we determined the complete genome sequences of B. cereus strains isolated from nosocomial infection cases in Japanese hospitals.

Novel Sequence Type in Bacillus cereus Strains Associated with Nosocomial Infections and Bacteremia, Japan

This sequence type was dominant in isolates from bacteremia patients in 3 hospitals.

Bacillus cereus is associated with foodborne illnesses characterized by vomiting and diarrhea. Although some B. cereus strains that cause severe extraintestinal infections and nosocomial infections are recognized as serious public health threats in healthcare settings, the genetic backgrounds of B. cereus strains causing such infections remain unknown. By conducting pulsed-field gel electrophoresis and multilocus sequence typing, we found that a novel sequence type (ST), newly registered as ST1420, was the dominant ST isolated from the cases of nosocomial infections that occurred in 3 locations in Japan in 2006, 2013, and 2016. Phylogenetic analysis showed that ST1420 strains belonged to the Cereus III lineage, which is much closer to the Anthracis lineage than to other Cereus lineages. Our results suggest that ST1420 is a prevalent ST in B. cereus strains that have caused recent nosocomial infections in Japan.

A Rare Case of Native Mitral Valve Bacillus Cereus Endocarditis Culminating Into a Cerebrovascular Infarction

We report a case of a 56-year-old man who presented initially with a sudden onset of right-sided facial droop and weakness, aphasia, and confusion with no associated fever, chills, syncope, fatigue, weight loss, night sweats, nausea, vomiting, diarrhea, odontalgia, palpitations, cough, or dyspnea. Code stroke was called and the patient received tissue plasminogen activator (tPA) with subsequent resolution of his symptoms. Cranial magnetic resonance imaging showed left frontal punctate cortical restricted diffusion consistent with subacute to acute infarction. Transesophageal echocardiogram showed a severely thickened anterior mitral valve leaflet with a shaggy echodensity consistent with a vegetation. Blood cultures grew Bacillus cereus sensitive to clindamycin, trimethoprim sulfamethoxazole, and vancomycin. He was initially treated with ampicillin, clindamycin, and vancomycin and was eventually maintained solely on vancomycin. He had complete return of his neurological function and was discharged on intravenous antibiotic to complete a 6-week course.

A Case Series and Review of Bacillus Cereus Endocarditis from India

Introduction:

Bacillus cereus is a gram positive bacilli found commonly in the soil and environment. It is a bacteria rarely associated with endocarditis.

Case History:

Intravenous drug abuse, presence of valvular defects, pacemakers, immunodeficiency are some of the known risk factors for B.cereus endocarditis. We present here a case series of two patients with B.cereus endocarditis along with a review of the literature.

Conclusion:

This is the first report of B.cereus endocarditis from India to the best of our knowledge.

Persistent Bacillus cereus Bacteremia in 3 Persons Who Inject Drugs, San Diego, California, USA

Bacillus cereus is typically considered a blood culture contaminant; however, its presence in blood cultures can indicate true bacteremia. We report 4 episodes of B. cereus bacteremia in 3 persons who inject drugs. Multilocus sequence typing showed that the temporally associated infections were caused by unrelated clones.

Intravenous Drug Abuse by Patients Inside the Hospital: A Cause for Sustained Bacteremia

Patients with history of intravenous drug abuse are noted to be at risk of several infections including HIV, endocarditis, and other opportunistic infections. We report the case of a patient with sustained Bacillus cereus bacteremia despite use of multiple antibiotic regimens during his inpatient stay. Our case highlights the importance of high suspicion for active drug use inside the hospital in such patients. This is important in order to minimize unnecessary diagnostic workup and provide adequate treatment and safe hospital stay for these patients.

Central Venous Access Device-Related Bacillus Cereus Endocarditis: A Case Report and Review of the Literature

Bacillus cereus typically presents as a gastrointestinal infection, but rarely manifests as systemic disease. This report describes a case of B. cereus-related endocarditis that presented as a sickle cell crisis and bacteremia. Initial clinical suspicion was for laboratory contamination of blood cultures. The case herein described is intended to demonstrate an uncommon presentation of B. cereus infection and highlights the value of an aggressive need to further investigate and interpret unexpected blood culture findings in clinical practice, early adequate antimicrobial therapy, prompt diagnosis, and consideration to urgent surgical interventions in such cases.

A cluster of Bacillus cereus bacteremia cases among injection drug users

Bacillus cereus is a ubiquitous spore-forming organism that is infrequently implicated in extraintestinal infections. The authors report three cases of B cereus bacteremia among injection drug users presenting within one month to an urban tertiary care hospital. Treatment with intravenous vancomycin was successful in all three cases. While temporal association suggested an outbreak, molecular studies of patient isolates using pulsed-field gel electrophoresis did not suggest a common source. A review of the association of B cereus infections with heroin use and treatment of this pathogen is provided.

Murine model of Bacillus cereus gastrointestinal infection

Bacillus cereus is a spore-forming micro-organism responsible for foodborne illness. In this study, we focus on the host response following intragastric challenge with a pathogenic B. cereus strain (B10502) isolated from a foodborne outbreak. C57BL/6J female mice were infected by gavage with strain B10502. Controls were administered with PBS. Infection leads to significant modification in relevant immune cells in the spleen, Peyer's patches (PP) and mesenteric lymph nodes (MLN). These findings correlated with an increase in the size of PP as compared with uninfected controls. Histological studies showed that B. cereus infection increased the ratio of intestinal goblet cells and induces mononuclear cell infiltrates in spleen at 5 days post-infection. Evaluation of cytokine mRNA expression demonstrated a significant increase in IFN-γ in MLN after 2 days of infection. The present work demonstrates that infection of mice with vegetative B. cereus is self-limited. Our findings determined relevant cell populations that were involved in the control of the pathogen through modification of the ratio and/or activation.

Pacemaker-associated Bacillus cereus endocarditis

We report the case of a pacemaker-associated Bacillus cereus endocarditis in a nonimmunocompromised patient. Antibiotic treatment was ineffective, and the pacemaker had to be removed. B. cereus was cultured from several blood samples and from the pacemaker electrodes. This case underlines the contribution of the rpoB gene for Bacillus species determination.

Bacillus cereus endocarditis in native aortic valve

Bacillus cereus endocarditis is rare. It has been implicated in immunocompromised individuals, especially in intravenous drug users as well as in those with a cardiac prosthesis. The patient was a 31-year-old ex-intravenous drug addict with a past history of staphylococcal pulmonary valve endocarditis, who presented with symptoms of decompensated cardiac failure. Echocardiography showed severe aortic regurgitation with an oscillating vegetation seen on the right coronary cusp of the aortic valve. The blood cultures grew Bacillus cereus. We report this as a rare case of Bacillus cereus endocarditis affecting a native aortic valve.