Acute inflammation and loss of retinal architecture and function during experimental Bacillus endophthalmitis.

Rapid vision loss and explosive inflammation are devastating consequences of Bacillus endophthalmitis that have not been well defined. We therefore analyzed the evolution of intraocular inflammation and loss of retinal architecture and function during experimental Bacillus endophthalmitis. Mice were intravitreally injected with 100 CFU of B. cereus, and eyes were analyzed for bacterial growth, retinal function, architectural changes and retinal cellular stress, inflammatory cytokines, and infiltrating cells. Retinal electrophysiologic and structural changes began as early as 4 to 6 hr postinfection. Significant declines in retinal function paralleled the loss of retinal architecture. Glial fibrillary acidic protein (GFAP) was detected in retina, indicating potential stress. Polymorphonuclear leukocyte (PMN) infiltration into the vitreous began as early as 4 hr postinfection, coinciding with a significant increase in TNF-alpha in the eye. These results indicated that acute inflammation and detrimental architectural and electrophysiologic changes in the retina began earlier than once thought, suggesting that therapeutic intervention should be given at the earliest possible time to avoid vision loss during Bacillus endophthalmitis.

Necrotizing gastritis due to Bacillus cereus in an immunocompromised patient.

Bacillus cereus is increasingly being acknowledged as a serious bacterial pathogen in immunocompromised patients. We present a case of acute necrotizing gastritis caused by B. cereus in a 37-year-old woman with acute myeloblastic leukemia, who recovered following total parenteral nutrition and treatment with imipenem and vancomycin. B. cereus was isolated from gastric mucosa and blood cultures. Up to now, no case of acute necrotizing gastritis due to this organism has been reported.

Characterization of Mexican Bacillus thuringiensis strains toxic for lepidopteran and coleopteran larvae.

Bacillus thuringiensis strains C-4, C-9, GM-7, and GM-10, isolated from northeast Mexico and selected for their high toxicity against lepidopteran and coleopteran pests, were characterized following United States Environmental Protection Agency (EPA)'s guidelines. Flagellar serotyping revealed that GM-7 and GM-10 belonged to serotype aizawai, whereas C-4, C-9 corresponded to the kumamotoensis serotype. GM-10 and C-9 were also shown to be the most effective against lepidoptera and coleoptera larvae, respectively. None of the tested strains produced beta-exotoxin or showed activity against mosquitoes. GM-7 and GM-10 were sensitive to R-41 and CP-51 phages. All strains synthesized crystal proteins of 130-140 kDa. PCR analysis showed that C-4, GM-7, and GM-10 strains expressed cry1 genes, and C-9 expressed cry3 and cry7/8 genes, but not cry1. However, the C-9 strain had no cross-reaction with antisera raised against Cry3A and Cry7A proteins. GM-7 and GM-10 were sensitive to R-41 and CP-51 phages. When the delta-endotoxin (crystal) from the four strains was subcutaneously injected to Balb/c mice, alone or in combination with spores, only C-4 and C-9 provoked tissue necrosis similar to that caused by the beta-exotoxin producer HD-41. Tissue necrosis was prevented with the injection of pentoxifylline, an inhibitor of tumor necrosis factor alpha (TNF-alpha) production, suggesting a role of this cytokine in the observed effect. Our results demonstrated that GM-7 and GM-10 strains are effective and suitable for control of lepidopteran pests and safe for mammals under EPA regulations. The potential of the C-9 strain for the control of several coleopteran pests, and the induction of tissue necrosis in mice by C-4 and C-9 strains, are discussed.

Histopathological and histochemical changes in honeybee larvae (Apis mellifera L.) after infection with Bacillus larvae, the causative agent of American foulbrood disease.

Morphological, histochemical and cytochemical changes were examined in honeybee larvae after infection with the bacterium Bacillus larvae. The results indicate cell necrosis in the midgut epithelium accompanied by increasing cell vacuolization and nuclear pyknosis following per os inoculation with B. larvae. Many autolysosomes were positive for acid phosphatase. Non-vacuolar acid phosphatase activity was also found in lysed cell compartments. No such activity was found in regenerative epithelial cells. Degradation of haemocytes, salivary glands and other tissues was also observed. Histochemical analyses after per cutaneous inoculation with B. larvae of three- and five-day-old honeybee larvae show intense non-vacuolar acid phosphatase activity followed by disintegration of infected salivary glands, epithelial cell cytoplasm and haemocytes.

Fluoroscopically guided percutaneous disk aspiration in 10 dogs with diskospondylitis.

Fluoroscopically guided percutaneous fine-needle aspiration of the intervertebral disk space was performed in 10 dogs with diskospondylitis. Positive bacterial cultures were obtained from 9 of 12 aspirated disk spaces, 1 of 6 blood cultures, and 6 of 10 urine cultures. Positive disk cultures were obtained from 2 dogs with negative blood and urine cultures and from 2 additional dogs with low numbers of Staphylococcus in urine cultures. Adverse clinical sequelae of the procedure were not noted. Percutaneous fine-needle aspiration of the intervertebral disk space is an alternative technique to surgical biopsy to obtain positive bacterial cultures from dogs with diskospondylitis.

[Intracerebral hemorrhage and multiple brain abscesses caused by Bacillus cereus within the scope of acute lymphatic leukemia]. / Intrazerebrale Blutung und multiple Hirnabszesse durch Bacillus cereus im Rahmen einer akuten lymphatischen Leukämie.

Multiple hematogenic brain abscesses in immunosuppression are occasionally caused by rare and primary apathogenic causative agents. We report a first case of an isolated CNS infection by Bacillus cereus, which led to death from multiple brain abscesses and an intracerebral hemorrhage, probably caused by the infection, within 4 days. The underlying disease leading to immunosuppression was acute lymphatic leukemia in complete remission. In spite of antibiotic therapy the chemotherapy-induced neutropenia enabled unhindered spreading of the necrotizing infection, which was verified by histological analysis. The production of potent toxins such as hemolysin and cerelolysin by B. cereus leads to rapid and fulminant tissue destruction usually involving the walls of blood vessels.

Fatal Bacillus cereus meningoencephalitis in an adult with acute myelogenous leukemia.

Bacillus cereus, a ubiquitous, endospore-forming, aerobic gram-positive bacillus, is primarily associated with toxin-mediated food poisoning. Frequently, isolates of Bacillus species from clinical specimens are discussed as contaminants. We report a rapidly fatal case of disseminated infection due to B cereus in a patient receiving induction chemotherapy for M0 acute leukemia. A short clinical syndrome of nausea and vomiting preceded neurologic symptoms. Autopsy showed extensive meningoencephalitis with subarachnoid hemorrhage and multiple liver abscesses. Areas of necrosis were devoid of any inflammatory response consistent with a severely immunocompromised state. The organism was isolated from immediate premortem and autopsy blood specimens. This case illustrates the possibility and severity of true B cereus infections in immunocompromised patients, the clinicopathologic features of which are as yet not well defined.

Growth of Tyzzer's organisms in preneoplastic hepatocytes of rats.

Tyzzer's disease in rats carrying preneoplastic or neoplastic lesions in the liver was studied histopathologically and immunohistochemically. The formation of necrotic foci and the growth of organisms were detected within both glutathione S-transferase placental type (GST-P) positive preneoplastic or neoplastic hepatocyte areas and GST-P negative areas. However, plasma glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) values and number of necrotic foci of infected animals having preneoplastic lesions in the liver were smaller than those of infected animals receiving no carcinogenic procedure. These results suggest that the environment consisted of preneoplastic hepatocytes was unsuitable for the growth of organisms as compared with that of intact hepatocytes though the organism could grow within the preneoplastic hepatocytes.