Virulence Factor Profiles and Antimicrobial Susceptibilities of Ocular<i>Bacillus</i>Isolates

Callegan, Michelle C.; Cochran, Daniel C.; Kane, Scott T.; Ramadan, R.; Chodosh, James; McLean, Celeste; Stroman, David W.

doi:10.1080/02713680600850963

Cited by 55 publications

(54 citation statements)

References 47 publications

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“…B. cereus causes the vast majority of Bacillus endophthalmitis cases. However, endophthalmitis can also be caused by Bacillus thuringiensis, a bacterium commonly used for organic gardening and farming that is genetically and phenotypically similar to B. cereus (Callegan, et al, 2006a). For B. cereus and B. thuringiensis, the quorum sensing transcriptional regulator plcR controls the expression of many extracellular virulence factors (Agaisse, et al, 1999).…”

Section: Bacillusmentioning

confidence: 99%

Bacterial endophthalmitis: Therapeutic challenges and host–pathogen interactions

Callegan

Gilmore

Gregory

et al. 2007

Progress in Retinal and Eye Research

156

153

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Endophthalmitis is an infection of the posterior segment of the eye that frequently results in loss of vision. This devastating result occurs despite prompt and often aggressive therapeutic and surgical intervention. Over the past decade, research has centered on determining the bacterial and host factors involved in this potentially blinding disease. The initial focus on the bacterial factors responsible for intraocular virulence has recently expanded into analysis the inflammatory response to infection, including the molecular and cellular interactions between the pathogen and host. This review discusses the epidemiology and therapeutic challenges posed by endophthalmitis, as well as recent findings from the analysis of interactions between the host and pathogen. Based on these findings, a model for the pathogenesis of endophthalmitis is presented. A more comprehensive understanding of the molecular and cellular interactions taking place between pathogen and host during endophthalmitis will expose possible therapeutic targets designed to arrest the infection and prevent vision loss.

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Section: Bacillusmentioning

confidence: 99%

Bacterial endophthalmitis: Therapeutic challenges and host–pathogen interactions

Callegan

Gilmore

Gregory

et al. 2007

Progress in Retinal and Eye Research

156

153

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“…Cultures of wild-type or mutant B. cereus were propagated in brain heart infusion (BHI) medium and diluted into RPE cell culture medium to a final concentration of 10 5 CFU/ml. Suspensions were further diluted to the appropriate inocula of 10 4 , 10 3 , or 10 2 CFU/ml. Each well was inoculated with 1 ml bacterial solution, and samples were harvested for analysis at 2-h intervals for 8 h. These strains have been shown to infect rabbit and mouse eyes, resulting in explosive inflammation similar to that seen in human cases (12,49).…”

Section: Methodsmentioning

confidence: 99%

Bacillus cereusInduces Permeability of an In Vitro Blood-Retina Barrier

Moyer¹,

Ramadan

Thurman³

et al. 2008

Infect Immun

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Most Bacillus cereus toxin production is controlled by the quorum-sensing-dependent, pleiotropic global regulator plcR, which contributes to the organism's virulence in the eye. The purpose of this study was to analyze the effects of B. cereus infection and plcR-regulated toxins on the barrier function of retinal pigment epithelium (RPE) cells, the primary cells of the blood-retina barrier. Human ARPE-19 cells were apically inoculated with wild-type or quorum-sensing-deficient B. cereus, and cytotoxicity was analyzed. plcR-regulated toxins were not required for B. cereus-induced RPE cytotoxicity, but these toxins did increase the rate of cell death, primarily by necrosis. B. cereus infection of polarized RPE cell monolayers resulted in increased barrier permeability, independent of plcR-regulated toxins. Loss of both occludin and ZO-1 expression occurred by 8 h postinfection, but alterations in tight junctions appeared to precede cytotoxicity. Of the several proinflammatory cytokines analyzed, only interleukin-6 was produced in response to B. cereus infection. These results demonstrate the deleterious effects of B. cereus infection on RPE barrier function and suggest that plcRregulated toxins may not contribute significantly to RPE barrier permeability during infection.

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“…(1 ). These Bacillus infections can be very severe (a total loss of vision occurs in Յ70% of cases (3 )), and enucleation is the outcome in Ͼ50% of Bacillusassociated cases (1,3 ). The most common species of Bacillus associated with posttraumatic endophthalmitis are B. cereus, B. subtilis, and B. licheniformis.…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, Bacillus spp. have been shown to rapidly migrate to all tissues within the eye, allowing the organism to move to protected regions of the eye, thus evading antimicrobial treatment (3 ). For the best outcome, posttraumatic infectious endophthalmitis treatment should be initiated within 24 h, and both wound closure and systemic antimicrobial treatment are recommended (4 ).…”

Section: Discussionmentioning

confidence: 99%

Be Serious: Posttraumatic Endophthalmitis

McMullen

Burnham

2016

Clinical Chemistry

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An 82-year-old man with dementia presented to his primary care physician with a chief complaint of left eye swelling for 2 days. He was prescribed ciprofloxacin ophthalmic drops. A few days later, his symptoms had not improved, and he presented to the emergency department at an outside hospital with ongoing eye pain. He had loss of vision in his left eye. He noted that he may have fallen approximately 2 weeks earlier but did not seek medical care. Antimicrobial therapy with intravenous ceftriaxone and vancomycin was initiated. MRI demonstrated detachment of the left retina, significant inflammation of the circumference of the eye, and an irregular globe contour that was of concern for rupture. On the basis of these findings, he was transferred to our hospital for further management; an emergent ophthalmology consultation revealed fulminant endophthalmitis. The patient's antimicrobial therapy was changed to intravenous cefazolin.An evisceration of his left eye was performed the following day without complication. An ocular swab was sent to the microbiology laboratory for aerobic culture and Gram stain, and the intraocular contents were sent to pathology. Pathology confirmed acute panophthalmitis, and bacilli were documented in the sample with Gomori methenamine silver stain. Gram stain of material from the swab showed abundant polymorphonuclear leukocytes but no organisms. The next day, rare ␤-hemolytic colonies were noted on 5% sheep's blood agar (Remel) and rare gray colonies were growing on chocolate agar plate (Remel). The organism was determined to be a catalase-positive, spore-forming, gram-positive Bacillus. The organism was identified as Bacillus anthracis by MALDI-TOF MS (MALDI Biotyper, Bruker Daltonics) with a confidence score value that would be acceptable for a species-level identification.In accordance with laboratory protocols for identification of select agents (potential biothreat/bioterrorism agents), the case was brought to the attention of the medical director. The isolate was confirmed to be motile. Because the organism was ␤-hemolytic and motile, B. anthracis was rapidly ruled out, and the organism was presumed to be a member of the B. cereus group on the basis of morphologic and biochemical findings. Susceptibility testing was performed with a gradient diffusion method (Etest, bioMérieux), and the isolate was found to be susceptible to ciprofloxacin, clindamycin, and vancomycin and resistant to trimethoprim-sulfamethoxazole. The patient's antimicrobial therapy was streamlined to oral moxifloxacin and topical erythromycin ointment; he was discharged 6 days after his surgery to a skilled nursing facility and has continued to do well. DISCUSSIONPosttraumatic endophthalmitis makes up 25%-30% of all infectious endophthalmitis cases (1 ). Infection is derived either from inoculation of the endogenous flora from the periorbital region into the open wound or direct inoculation of environmental organisms into the eye during trauma (2 ). Most cases are caused by gram-positive bacteria, with approxima...

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Virulence Factor Profiles and Antimicrobial Susceptibilities of OcularBacillusIsolates

Cited by 55 publications

References 47 publications

Bacterial endophthalmitis: Therapeutic challenges and host–pathogen interactions

Bacterial endophthalmitis: Therapeutic challenges and host–pathogen interactions

Bacillus cereusInduces Permeability of an In Vitro Blood-Retina Barrier

Be Serious: Posttraumatic Endophthalmitis

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