Summary: Bacillus cereus is a Gram-positive aerobic or facultatively anaerobic, motile, spore-forming, rod-shaped bacterium that is widely distributed environmentally. While B. cereus is associated mainly with food poisoning, it is being increasingly reported to be a cause of serious and potentially fatal non-gastrointestinal-tract infections. The pathogenicity of B. cereus, whether intestinal or nonintestinal, is intimately associated with the production of tissue-destructive exoenzymes. Among these secreted toxins are four hemolysins, three distinct phospholipases, an emesis-inducing toxin, and proteases. The major hurdle in evaluating B. cereus when isolated from a clinical specimen is overcoming its stigma as an insignificant contaminant. Outside its notoriety in association with food poisoning and severe eye infections, this bacterium has been incriminated in a multitude of other clinical conditions such as anthrax-like progressive pneumonia, fulminant sepsis, and devastating central nervous system infections, particularly in immunosuppressed individuals, intravenous drug abusers, and neonates. Its role in nosocomial acquired bacteremia and wound infections in postsurgical patients has also been well defined, especially when intravascular devices such as catheters are inserted. Primary cutaneous infections mimicking clostridial gas gangrene induced subsequent to trauma have also been well documented. B. cereus produces a potent β-lactamase conferring marked resistance to β-lactam antibiotics. Antimicrobials noted to be effective in the empirical management of a B. cereus infection while awaiting antimicrobial susceptibility results for the isolate include ciprofloxacin and vancomycin.

Bacillus cereus, a Volatile Human Pathogen

Bacillus cereus is a ubiquitous soil bacterium responsible for two types of food-associated gastrointestinal diseases While the emetic type, a food intoxication, manifests in nausea and vomiting, food infections with enteropathogenic strains cause diarrhea and abdominal pain Causative toxins are the cyclic dodecadepsipeptide cereulide, and the proteinaceous enterotoxins hemolysin BL (Hbl), nonhemolytic enterotoxin (Nhe) and cytotoxin K (CytK), respectively This review covers the current knowledge on distribution and genetic organization of the toxin genes, as well as mechanisms of enterotoxin gene regulation and toxin secretion In this context, the exceptionally high variability of toxin production between single strains is highlighted In addition, the mode of action of the pore-forming enterotoxins and their effect on target cells is described in detail The main focus of this review are the two tripartite enterotoxin complexes Hbl and Nhe, but the latest findings on cereulide and CytK are also presented, as well as methods for toxin detection, and the contribution of further putative virulence factors to the diarrheal disease

The Food Poisoning Toxins of Bacillus cereus

Neonates born to mothers with Graves' disease are at risk for significant morbidity and mortality and need to be appropriately identified and managed. Because no consensus guidelines regarding the treatment of these newborns exist, we sought to generate a literature-based management algorithm. The suggestions include the following: (1) Base initial risk assessment on maternal thyroid stimulating hormone (TSH) receptor antibodies. If levels are negative, no specific neonatal follow-up is necessary; if unavailable or positive, regard the newborn as "at risk" for the development of hyperthyroidism. (2) Determine levels of TSH-receptor antibodies in cord blood, or as soon as possible thereafter, so that newborns with negative antibodies can be discharged from follow-up. (3) Measurement of cord TSH and fT4 levels is not indicated. (4) Perform fT4 and TSH levels at day 3 to 5 of life, repeat at day 10 to 14 of life and follow clinically until 2 to 3 months of life. (5) Use the same testing schedule in neonates born to mothers with treated or untreated Graves' disease. (6) When warranted, use methimazole (MMI) as the treatment of choice; β-blockers can be added for sympathetic hyperactivity. In refractory cases, potassium iodide may be used in conjunction with MMI. The need for treatment of asymptomatic infants with biochemical hyperthyroidism is uncertain. (7) Assess the MMI-treated newborn on a weekly basis until stable, then every 1 to 2 weeks, with a decrease of MMI (and other medications) as tolerated. MMI treatment duration is most commonly 1 to 2 months. (8) Be cognizant that central or primary hypothyroidism can occur in these newborns.

Management of Neonates Born to Mothers With Graves’ Disease

Bacillus cereus meningitis is a rare disease with a very high mortality rate in neonates. The authors present the rare case of a premature infant with B. cereus bacteremia and subsequent intracranial abscesses. In addition to aggressive medical therapy, surgical drainage was performed via a left frontal mini-craniotomy. At 15 months of age, the patient had mild developmental delay, cortical blindness, and sensorineural hearing loss. The clinical case is described and difficulties in the management of B. cereus meningoencephalitis in infants are discussed.

Successful Surgical Drainage and Aggressive Medical Therapy in a Preterm Neonate with Bacillus cereus Meningitis

Contralateral suppression of transient otoacoustic emissions in 42 premature babies (84 ears; post-conceptional age [PCA] 30–36 weeks) was compared to that of 39 full-term babies (78 ears; PCA: 37–45 weeks). Eighteen healthy adults and ten young children (5–14 years old) were studied as controls. Risk factors for hearing loss were registered in both preterm and full-term groups. An ILO–92 otoacoustic emission recording system was used to deliver linear clicks to the ear examined and broadband noise to the contralateral ear in an alternating on and off mode.Suppression in full-term babies was statistically higher than in preterms, whereas no differences existed between children and adults and children and full-terms. Peripheral auditory lateralization was evident in adults but was observed only as a trend in newborns. Only prematurity at the time of examination and aminoglycoside treatment for more than seven days had a negative impact on suppression.The results support the conclusion that maturation of th...

Maturation of the auditory system: 2. Transient otoacoustic emission suppression as an index of the medial olivocochlear bundle maturation.

A case of Bacillus cereus meningitis in a term neonate without identifiable risk factors or source of the organism is presented. Prompt identification of the organism and treatment resulted in a favourable outcome.

Bacillus cereus meningitis in a term neonate.

Transient otoacoustic emissions in the detection of olivocochlear bundle maturation.

A case of an 8-day-old preterm neonate with heart failure, pulmonary hypertension, and myocardial ischemia due to hyperthyroidism is reported. Treatment of the disease initially with b-blockers and, upon establishment of hyperthyroidism, with propylthiouracil reversed all cardiac abnormalities. Contrary to the rule, diagnosis of hyperthyroidism in the mother was established following the diagnosis of the condition in her baby. On long-term follow-up (10 years), the child has developed normally, remains euthyroid with normal electrocardiogram. To our knowledge, diagnosis and reversal of the above-mentioned ischemic abnormalities have not been previously reported in neonates.

A unique case of reversible myocardial ischemia in a hyperthyroid neonate.

Editor—We read with interest the paper by Cuttini et al .1Although policy on parental visiting is an easier issue to evaluate, parental participation in decision making, particularly in decisions with strong ethical overtones, is much more complex. It is difficult to evaluate with accuracy, and by its nature is much more controversial. The paper does not stress that data collected from each participating unit, through a structured questionnaire completed by the unit coordinator, represent policies—that is, the intention and stance of each unit towards the …

https://fn.bmj.com/content/fetalneonatal/83/2/F160.10.full.pdf

Heracles D. Dellagrammaticas

Papers

Bacillus cereus meningitis in a term neonate.

Transient otoacoustic emissions in the detection of olivocochlear bundle maturation.

A unique case of reversible myocardial ischemia in a hyperthyroid neonate.

Parental visiting in neonatal units