Successful treatment of Bacillus cereus infection with ciprofloxacin

Childhood Obesity: A Potential Key Factor in the Development of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a malignant primary tumor type of the central nervous system (CNS). This type of brain tumor is rare and is responsible for 12-15% of all brain tumors. The typical survival rate of GBM is only 12 to 14 months. GBM has a poor and unsatisfactory prognosis despite advances in research and therapeutic interventions via neurosurgery, radiation, and chemotherapy. The molecular heterogeneity, aggressive nature, and occurrence of drug-resistant cancer stem cells in GB restricts the therapeutic efficacy. Interestingly, the CNS tumors in children are the second most usual and persistent type of solid tumor. Since numerous research studies has shown the association between obesity and cancer, childhood obesity is one of the potential reasons behind the development of CNS tumors, including GBM. Obesity in children has almost reached epidemic rates in both developed and developing countries, harming children's physical and mental health. Obese children are more likely to face obesity as adults and develop non-communicable diseases such as diabetes and cardiovascular disease as compared to adults with normal weight. However, the actual origin and cause of obesity are difficult to be pointed out, as it is assumed to be a disorder with numerous causes such as environmental factors, lifestyle, and cultural background. In this narrative review article, we discuss the various molecular and genetic drivers of obesity that can be targeted as potential contributing factors to fight the development of GBM in children.

Assessment and molecular characterization of Bacillus cereus isolated from edible fungi in China

Background

Bacillus cereus is a foodborne pathogen commonly found in nature and food and can cause food spoilage and health issues. Although the prevalence of B. cereus in foods has been reported worldwide, the extent of contamination in edible fungi, which has become increasingly popular as traditional or functional food, is largely unknown. Here we investigated the prevalence, toxin genes’ distribution, antibiotic resistance, and genetic diversity of B. cereus isolated from edible fungi in China.

Results

Six hundred and ninety-nine edible fungi samples were collected across China, with 198 (28.3%) samples found to be contaminated by B. cereus, with an average contamination level of 55.4 most probable number (MPN)/g. Two hundred and forty-seven B. cereus strains were isolated from the contaminated samples. Seven enterotoxin genes and one cereulide synthetase gene were detected. The detection frequencies of all enterotoxin genes were ≥ 80%, whereas the positive rate of the cesB gene in B. cereus was 3%. Most isolates were resistant to penicillins, β-lactam/β-lactamase inhibitor combinations, cephems, and ansamycins, but were susceptible to penems, aminoglycosides, macrolides, ketolide, glycopeptides, quinolones, phenylpropanol, tetracyclines, lincosamides, streptogramins, and nitrofurans. Meanwhile, 99.6% of all isolates displayed multiple antimicrobial resistance to three or more classes of antimicrobials. Using genetic diversity analysis, all isolates were defined in 171 sequence types (STs), of which 83 isolates were assigned to 78 new STs.

Conclusions

This study provides large-scale insight into the prevalence and potential risk of B. cereus in edible fungi in China. Approximately one-third of the samples were contaminated with B. cereus, and almost all isolates showed multiple antimicrobial resistance. Detection frequencies of all seven enterotoxin genes were equal to or more than 80%. These new findings may indicate a need for proper pre-/post-processing of edible fungi to eliminate B. cereus, thereby preventing the potential risk to public health.

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.

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.

Liver abscess and sepsis with Bacillus pantothenticus in an immunocompetent patient: A first case report

Bacillus species are aerobic, gram-positive, spore forming rods that are usually found in the soil, dust, streams, and other environmental sources. Except for Bacillus. anthracis (B. anthracis), most species display low virulence, and only rarely cause infections in hosts with weak or damaged immune systems. There are two case reports of B. cereus as a potentially serious bacterial pathogen causing a liver abscess in an immunologically competent patient. We herein report a case of liver abscess and sepsis caused by B. pantothenticus in an immunocompetent patient. Until now, no case of liver abscess due to B. pantothenticus has been reported.

Genetic diversity of clinical isolates of Bacillus cereus using multilocus sequence typing

Background

Bacillus cereus is most commonly associated with foodborne illness (diarrheal and emetic) but is also an opportunistic pathogen that can cause severe and fatal infections. Several multilocus sequence typing (MLST) schemes have recently been developed to genotype B. cereus and analysis has suggested a clonal or weakly clonal population structure for B. cereus and its close relatives B. anthracis and B. thuringiensis. In this study we used MLST to determine if B. cereus isolates associated with illnesses of varying severity (e.g., severe, systemic vs. gastrointestinal (GI) illness) were clonal or formed clonal complexes.

Results

A retrospective analysis of 55 clinical B. cereus isolates submitted to the Centers for Disease Control and Prevention between 1954 and 2004 was conducted. Clinical isolates from severe infections (n = 27), gastrointestinal (GI) illness (n = 18), and associated isolates from food (n = 10) were selected for analysis using MLST. The 55 isolates were diverse and comprised 38 sequence types (ST) in two distinct clades. Of the 27 isolates associated with serious illness, 13 clustered in clade 1 while 14 were in clade 2. Isolates associated with GI illness were also found throughout clades 1 and 2, while no isolates in this study belonged to clade 3. All the isolates from this study belonging to the clade 1/cereus III lineage were associated with severe disease while isolates belonging to clade1/cereus II contained isolates primarily associated with severe disease and emetic illness. Only three STs were observed more than once for epidemiologically distinct isolates.

Conclusion

STs of clinical B. cereus isolates were phylogenetically diverse and distributed among two of three previously described clades. Greater numbers of strains will need to be analyzed to confirm if specific lineages or clonal complexes are more likely to contain clinical isolates or be associated with specific illness, similar to B. anthracis and emetic B. cereus isolates.

Bacillus cereus pneumonia in a patient with acute lymphoblastic leukemia

Reported here is a case of Bacillus cereus pneumonia that occurred in a patient with acute lymphoblastic leukemia. The presentation was severe, essentially marked by respiratory distress and pleuritic chest pain. Classic empirical treatment initiated for febrile neutropenia did not cover this rare pathogen and appropriate therapy was therefore delayed. B. cereus is most often a culture contaminant, but it can also be responsible for self-limited gastrointestinal intoxication and, more rarely, severe systemic diseases. Virulence in the case of systemic disease is attributed to tissue necrosis mediated by toxin release. B. cereus pneumonia, as described in the English-language literature, mainly affects immunocompromised patients and most often has a fatal outcome. Thus, the identification of B. cereus in clinical specimens of severely ill immunocompromised patients should lead physicians to question its clinical significance.

Pseudomembranous tracheobronchitis due to Bacillus cereus

We present a case of a rapidly progressive pseudomembranous tracheobronchitis and pneumonia in a 52-year-old woman with severe aplastic anemia. Bacillus cereus was isolated from bronchoalveolar lavage fluids, blood cultures, and pseudomembrane biopsy specimens; despite intensive antibiotic treatment, the patient's condition deteriorated rapidly. To our knowledge, this is the first report of a B. cereus infection that has caused pseudomembranous tracheobronchitis, possibly because of the production of bacterial toxins.

Fulminating bacteremia and pneumonia due to Bacillus cereus

We present two cases of rapidly progressing, fatal pneumonia caused by Bacillus cereus. These cases are interesting in that B. cereus, even from blood or sputum specimens, may often be considered a contaminant and receive inadequate attention. Also of interest was the fact that the two patients resided in the same area of the state, were welders by trade, and became ill within a few days of each other, yet there was no epidemiologic link between them.

Bacillus cereus and related species

Bacillus cereus is a gram-positive aerobic or facultatively anaerobic spore-forming rod. It is a cause of food poisoning, which is frequently associated with the consumption of rice-based dishes. The organism produces an emetic or diarrheal syndrome induced by an emetic toxin and enterotoxin, respectively. Other toxins are produced during growth, including phospholipases, proteases, and hemolysins, one of which, cereolysin, is a thiol-activated hemolysin. These toxins may contribute to the pathogenicity of B. cereus in nongastrointestinal disease. B. cereus isolated from clinical material other than feces or vomitus was commonly dismissed as a contaminant, but increasingly it is being recognized as a species with pathogenic potential. It is now recognized as an infrequent cause of serious nongastrointestinal infection, particularly in drug addicts, the immunosuppressed, neonates, and postsurgical patients, especially when prosthetic implants such as ventricular shunts are inserted. Ocular infections are the commonest types of severe infection, including endophthalmitis, panophthalmitis, and keratitis, usually with the characteristic formation of corneal ring abscesses. Even with prompt surgical and antimicrobial agent treatment, enucleation of the eye and blindness are common sequelae. Septicemia, meningitis, endocarditis, osteomyelitis, and surgical and traumatic wound infections are other manifestations of severe disease. B. cereus produces beta-lactamases, unlike Bacillus anthracis, and so is resistant to beta-lactam antibiotics; it is usually susceptible to treatment with clindamycin, vancomycin, gentamicin, chloramphenicol, and erythromycin. Simultaneous therapy via multiple routes may be required.