Bacillus cereus necrotizing pneumonia in a patient with nephrotic syndrome

Welder's Anthrax: A Tale of 2 Cases

Bacillus anthracis has traditionally been considered the etiologic agent of anthrax. However, anthrax-like illness has been documented in welders and other metal workers infected with Bacillus cereus group spp. harboring pXO1 virulence genes that produce anthrax toxins. We present 2 recent cases of severe pneumonia in welders with B. cereus group infections and discuss potential risk factors for infection and treatment options, including antitoxin.

Welder’s Anthrax: A Review of an Occupational Disease

Since 1997, nine cases of severe pneumonia, caused by species within the B. cereus group and with a presentation similar to that of inhalation anthrax, were reported in seemingly immunocompetent metalworkers, with most being welders. In seven of the cases, isolates were found to harbor a plasmid similar to the B. anthracis pXO1 that encodes anthrax toxins. In this paper, we review the literature on the B. cereus group spp. pneumonia among welders and other metalworkers, which we term welder’s anthrax. We describe the epidemiology, including more information on two cases of welder’s anthrax in 2020. We also describe the health risks associated with welding, potential mechanisms of infection and pathological damage, prevention measures according to the hierarchy of controls, and clinical and public health considerations. Considering occupational risk factors and controlling exposure to welding fumes and gases among workers, according to the hierarchy of controls, should help prevent disease transmission in the workplace.

Assessment of the safety and anti-inflammatory effects of three Bacillus strains in the respiratory tract

Chronic respiratory diseases are part of accumulating health problems partly due to worldwide increase in air pollution. By their antimicrobial and immunomodulatory properties, some probiotics constitute promising alternatives for the prevention and treatment of chronic respiratory diseases. We have isolated Bacillus strains from Korean fermented foods and selected three potentially probiotic strains (two Bacillus subtilis and one Bacillus amyloliquefaciens) based on safety, antimicrobial efficacy, activity against airborne pathogens and their immunomodulatory properties in vivo. Safety evaluation included in silico analysis for confirming absence of virulence genes. Safety for the respiratory tract was confirmed by an in vivo pathogenicity test using a murine model. Antimicrobial activity was displayed against several airborne pathogens. Potential antimicrobial metabolites such as 2,3-butanediol and propylene glycol were identified as possible antagonistic agents. Immunomodulatory properties in vitro were confirmed by upregulation of IL-10 expression in a macrophage cell line. Intranasal instillation and inhalation in an ovalbumin (OVA)-induced lung inflammation murine model reduced T helper type 2 (Th2) cytokines at transcriptional and protein levels in the lungs. The safety and potentially beneficial role of these Bacillus strains could be demonstrated for the respiratory tract of a murine model.

Necrotizing pneumonia (aetiology, clinical features and management)

PURPOSE OF REVIEW

Necrotizing pneumonia is a severe form of community-acquired pneumonia characterized by rapid progression of consolidation to necrosis and cavitation which may lead to pulmonary gangrene. Morbidity and mortality are high and chronic sequelae are frequent. The lack of guidance supports the review of the latest recommendations in the management of these pneumonias.

RECENT FINDINGS

Antibiotic therapy alone may not be enough to alter the course of the infection, and regimens, adjunctive therapies like intravenous immunoglobulins, surgery may be required to alter the course of the disease especially with pulmonary gangrene.

SUMMARY

The causative agents, clinical features and management of necrotizing pneumonias are discussed.

The cereus matter of Bacillus endophthalmitis

Bacillus cereus (B. cereus) endophthalmitis is a devastating intraocular infection primarily associated with post-traumatic injuries. The majority of these infections result in substantial vision loss, if not loss of the eye itself, within 12-48 h. Multifactorial mechanisms that lead to the innate intraocular inflammatory response during this disease include the combination of robust bacterial replication, migration of the organism throughout the eye, and toxin production by the organism. Therefore, the window of therapeutic intervention in B. cereus endophthalmitis is quite narrow compared to that of other pathogens which cause this disease. Understanding the interaction of bacterial and host factors is critical in understanding the disease and formulating more rational therapeutics for salvaging vision. In this review, we will discuss clinical and research findings related to B. cereus endophthalmitis in terms of the organism's virulence and inflammogenic potential, and strategies for improving of current therapeutic regimens for this blinding disease.

An unusual case of massive hemoptysis due to Bacillus cereus necrotizing pneumonia

Bacillus cereus is a gram-positive bacillus that is ubiquitously present in the environment, often regarded as a contaminant when isolated in clinical testing. Cases of B. cereus causing lower respiratory tract infections are sparse, with less than 20 reported in the literature, and even fewer as a cause of massive hemoptysis. The majority of cases occur in the setting of an immunosuppressed patient. We describe a case of a 59-year-old male with esophageal adenocarcinoma undergoing chemotherapy presenting with a right upper lobe necrotizing pneumonia secondary to B. cereus with consequent massive hemoptysis.

A Case of Fulminant Bacillus cereus Lung Necrosis in a Preterm Neonate

Bacillus cereus is a ubiquitous Gram-positive rod seldom considered pathogenic in clinical isolates. However, it possesses multiple virulence factors explaining why it has been linked to fulminant and pyogenic infections in vulnerable hosts. Its recovery from sterile samples in immunocompromised patients cannot be disregarded. Premature infants would fall into this category. We describe the case of a neonate born at 26 weeks of gestational age, who died of a rapidly progressive B. cereus necrotizing pneumonia following suspected nosocomial acquisition. The rapidity of his course and the autopsy findings of necrosis with minimal inflammation suggest a toxin-mediated process. Pathologists should be aware of this pathogen and obtain proper microbiological samples in the presence of such autopsy findings, as the diagnosis may have infection-prevention implications in health-care settings.

Fatal community-acquired Bacillus cereus pneumonia in an immunocompetent adult man: a case report

BACKGROUND

Bacillus cereus is a gram-positive rod bacterium that is responsible for food poisoning. It is naturally widely distributed, and thus often contaminates cultures. Although it is rarely considered responsible, it can cause serious infections under certain conditions. However, lethal infections, especially in immunocompetent patients, are rare.

CASE PRESENTATION

A healthy 60-year-old man developed community-acquired B. cereus pneumonia and alveolar hemorrhage unveiled by abrupt chest pain and hemoptysis with no other advance symptoms. B. cereus induced silent alveolar destruction without any local or systemic inflammatory response. Although the lesion resembled lung anthrax, there was no evidence of Bacillus anthracis toxin.

CONCLUSIONS

Some isolates of B. cereus can cause anthrax-like fulminant necrotizing pneumonia in immunocompetent patients. If this type of B. cereus were used as a means of bioterrorism, it may be quite difficult to recognize as bioterrorism. We should keep B. cereus in mind as a potential pathogen of fulminant human infectious disease.

Bacillus cereus pneumonia in an immunocompetent patient: a case report

Background

Bacillus cereus (B. cereus) rarely causes lower respiratory tract infections, although most reported cases of B. cereus pneumonia are fatal despite intensive antibiotic therapy. We present a case of B. cereus pneumonia in an immunocompetent patient.

Case presentation

An 81-year-old woman was transferred from a district general hospital to our hospital for treatment of congestive heart failure. The patient presented with a nonproductive cough, dyspnea, edema in both lower extremities, orthopnea, fever, and occult blood in the stool. A chest radiograph indicated bilateral pleural effusion and pulmonary congestion. After diuretic therapy and chest drainage, bilateral pleural effusion and pulmonary congestion improved. On day 2, she experienced severe respiratory distress. B. cereus was isolated from two blood sample cultures. On day 4, her condition had progressed to severe respiratory distress (PaO₂/FiO₂ ratio = 108). A chest radiograph and computed tomography indicated extensive bilateral infiltrates. She was transferred to the intensive care unit and was intubated. B. cereus was also isolated from five blood sample cultures at that time. After isolating B. cereus, we switched antibiotics to a combination of imipenem and levofloxacin, which were effective. She had no history of immunodeficiency, surgery, ill close contacts, risk factors for HIV or tuberculosis, recent central venous catheter insertion, or anthrax vaccination. She improved and was discharged from the intensive care unit after several days.

Conclusion

This is a rare case of B. cereus pneumonia in an immunocompetent patient, who subsequently recovered. Bacillus should be considered as a potential pathogen when immunocompetent patients develop severe pneumonia.

Bacillus cereus infection: 57 case patients and a literature review

OBJECTIVES

We aimed to study the characteristics of patients presenting with a Bacillus cereus infection in a university hospital.

METHODS

We performed a retrospective analysis of the clinical, biological, and treatment-related data of patients hospitalized in our university hospital between January 1st, 2008 and December 31st, 2012 and diagnosed with a B. cereus infection. We identified a subgroup of patients presenting with bacteremia and looked for risk factors for death within that group of patients.

RESULTS

We included 57 patients in our study; 31 (54.4%) were hospitalized in a medical ward. We identified 24 bacteremia case patients, including 17 patients presenting with bacteremia alone (29.8%). Other frequently observed infection sites were skin infections (16; 28.1%) and bone and joint infections (10; 17.5%). We recorded 9 deaths (11.8%); 2 patients, despite being on an appropriate antibiotic therapy, died from a medical device-related infection that had not been removed. The empirical administration of a beta-lactam antibiotic was significantly associated with death (P=0.022). Three patients presenting with recurrent bacteremia were identified. The patients only recovered once the infected device had been removed.

CONCLUSION

B. cereus infections may have various clinical presentations. Prospective data is needed to put forward a consensual treatment approach and guide physicians in choosing the appropriate antibiotic therapy and in removing the infected device.

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.