Bilateral acute pyogenic conjunctivitis with iritis induced by unilateral topical application of bacterial peptidoglycan muramyl dipeptide in adult rabbits.

The factors responsible for the conjunctivitis and iritis associated with acute ocular infection and post enteric inflammatory disease are not fully known. The pro-inflammatory activity of unilateral topical application of muramyl dipeptide (MDP; the smallest bio-active Gram-positive and Gram-negative bacterial cell wall component) was investigated in adult rabbits. The resultant bilateral conjunctivitis/iritis and pyogenic responses were characterized. Bilateral symptoms were graded by slit lamp examinations; tear fluid, Schirmer tests (tear production), blood and aqueous humor (AH) samples were obtained from MDP-treated and untreated rabbits. MDP concentration, gamma-glutamyltranspeptidase activity (GGT; key enzyme in glutathione recapture, xenobiotic detoxification, eicosanoid synthesis and neutrophil function), protein concentration, and tear cell density, cytology, and immunofluorescent antibody reactivity to GGT and calreticulin (CRT; MDP-binding protein) were determined. MDP was cleared from ipsilateral tears and serum by 6 h, but was undetected in mock-treated contralateral tears. Bilateral signs of acute transient pyogenic conjunctivitis, characterized by tearing, lid edema, conjunctival hyperemia, chemosis and leukocytic infiltrate with iritis (erythema and aqueous flare) were detected. Milder symptoms occurred in the mock-treated contralateral eyes. Bilateral symptoms, tear production, tear protein, GGT activity, and mucopurulent discharge (containing up to 2.5-5.0 × 10(6) cells/mL) were elevated 4-8 h post MDP and resolved to near pre-treatment levels by 24 h. Tear GGT activity and protein levels were higher in MDP-treated and mock-treated contralateral eyes than in eyes of untreated adult rabbits (p's < 0.001). Elevated tear GGT activity was associated with histopathology and increased vascular and epithelial permeability to serum protein, GGT-positive epithelia cells, macrophages and heterophils. Repeat MDP applications induced recurrent induction and resolution patterns of bilateral conjunctivitis/iritis and tear GGT activity, but ipsilateral GGT responses were lower. The results suggest unilateral topical MDP application to adult rabbit eyes induces a bilateral acute pyogenic conjunctivitis/iritis (PCI) characterized by increased vascular and epithelial permeability similar to acute bacterial conjunctivitis in man. The detection of CRT/GGT positive heterophils in tears suggests efferocytosis (phagocytosis of dead/dying cells). Tear GGT activity may be a useful means to quantify MDP-induced toxicity and extraocular inflammation.

Cat-scratch uveitis confirmed by histological, serological, and molecular diagnoses.

PURPOSE: To report a case of a cat-scratch uveitis caused by Bartonella henselae, which was confirmed by histology, serology, and polymerase chain reaction (PCR) methodology. METHODS: An iris nodule was biopsied from a 4-year-old child who was scratched by a kitten on the side of his face and developed redness of the eye associated with cervical lymphadenopathy. Sections of the iridectomy specimen were stained with hematoxylin-eosin, periodic acid-Schiff, and Warthin-Starry technique for histopathologic evaluation. Additionally, serologic tests and molecular diagnosis using B. henselae-specific PCR were performed. RESULTS: Histopathologically, sections of the iridectomy specimen showed a zonal granulomatous inflammation with a central iris necrotic abscess surrounded by a mantle of epithelioid histiocytes and more peripherally by lymphocytes and plasma cells. The Warthin-Starry stain disclosed scattered short bacilli within the necrotic abscess morphologically compatible with B. henselae. Report of serologic tests for B. henselae disclosed a negative immunoglobulin G antibody (negative: less than 12) and a positive immunoglobulin M antibody of 18 (positive: greater than 15). Other serologic studies including Toxocara, histoplasmin, blastomycin, coccidioidin, aspergillin, and Chlamydia were all negative. PCR was positive for B. henselae DNA. CONCLUSIONS: Our case showed a unilateral chronic granulomatous iritis with the histopathologic features compatible with CSD caused by B. henselae bacillus as demonstrated in the iris biopsy and confirmed by serology and PCR technique. This case is an example of a relatively rare uveal manifestation of CSD.

A highly virulent Staphylococcus aureus: rabbit anterior chamber infection, characterization, and genetic analysis.

PURPOSE: To describe and characterize a Staphylococcus aureus strain with unique virulence that overcomes host defenses of the rabbit anterior chamber and mimics clinical cases of postcataract surgery endophthalmitis. METHODS: Nine isolates of S. aureus were tested to determine their viability in the rabbit anterior chamber. Growth of UMCR1 in the anterior chamber was established and expressed as log colony-forming units per milliliter of aqueous humor. Pathologic changes produced by UMCR1 were documented by photographs, slit lamp examination, histopathologic analysis, and quantification of neutrophils. UMCR1 was characterized by antibiotic susceptibility, biochemical tests, ribotyping, genome restriction mapping, and multilocus sequence typing (MLST). RESULTS: UMCR1 was the only S. aureus strain that grew within the anterior chamber, reaching log 6.97 ± 0.18 CFU/mL by 16 hours after infection. Pathologic changes included conjunctival injection, chemosis, corneal edema, severe iritis, fibrin accumulation, and a 193-fold increase in neutrophils by 16 hours after infection. UMCR1 was only resistant to sulfamethoxazole and, like other S. aureus isolates, polymyxin B. UMCR1 also had biochemical reactions and a ribotype pattern typical of S. aureus. The genomic reconstruction analysis of UMCR1 was most similar to strains MW2 and MSSA476. MLST revealed a 1 in 3198 nucleotide difference between UMCR1 and strains MW2 and MSSA476. CONCLUSIONS: This study describes a unique S. aureus strain that overcomes host defenses and replicates in the anterior chamber. The survival and growth of this organism could be used for studies of S. aureus pathogenesis, host defenses, and effectiveness of antibiotics within the anterior chamber.

Specific roles of alpha-toxin and beta-toxin during Staphylococcus aureus corneal infection.

Staphylococcus aureus corneal infection results in extensive inflammation and tissue damage. Our previous studies of bacterial mutants have demonstrated a role for alpha-toxin in corneal virulence. This study analyzes, by genetic rescue experiments, the virulence of mutants affecting alpha-toxin and beta-toxin activity and demonstrates the ocular toxicity of these purified staphylococcal proteins. Three types of isogenic mutants were analyzed: (i) mutants specifically deficient in alpha-toxin (Hla) or beta-toxin (Hlb), (ii) a mutant deficient in both Hla and Hlb, and (iii) a regulatory mutant, deficient in the accessory gene regulator (agr), that produces reduced quantities of multiple exoproteins, including alpha- and beta-toxins. Plasmids coding for Hla and Hlb (pDU1212 and pCU1hlb, respectively) were used to restore toxin activity to mutants specifically deficient in each of these toxins. Either corneas were injected intrastromally with logarithmic-phase S. aureus or purified alpha- or beta-toxins were administered to normal eyes. Ocular pathology was evaluated by slit lamp examination and myeloperoxidase activity of infiltrating polymorphonuclear leukocytes. Corneal homogenates were cultured to determine the CFU per cornea. Eyes infected with the wild-type strain developed significantly greater corneal damage than eyes infected with Agr-, Hlb-, or Hla- strains. Epithelial erosions produced by parent strains were not produced by Agr- or Hla- strains. Hlb+ strains, unlike Hlb- strains, caused scleral edema. Plasmid pDU1212 restored corneal virulence to strain DU1090 (Hla-), and plasmid pCU1hlb restored corneal virulence to strain DU5719 (Hlb-). Application of purified alpha-toxin produced corneal epithelial erosions and iritis, while application of beta-toxin caused scleral inflammation. These studies confirm the role of alpha-toxin as a major virulence factor during S. aureus keratitis and implicate beta-toxin, a mediator of edema, as a lesser contributor to ocular damage.

Similarly increased serum IgA1 and IgA2 subclass antibody levels against Klebsiella pneumoniae bacteria in ankylosing spondylitis patients with/without extra-articular features.

IgA1 and IgA2 subclass serum antibodies against whole Klebsiella pneumoniae bacteria were studied earlier in the sera of 98 patients with ankylosing spondylitis (AS) and in 100 healthy blood donors by enzyme immunoassay. In this study, the patients were divided into groups according to the clinical picture, i.e., the presence or absence of iritis and enthesitis. The previous findings of increased IgA1 and IgA2 subclass antibody levels against K. pneumoniae in AS patients when compared to the healthy controls were not specifically associated with any single AS patient group in the present study, but instead were similarly seen in all patient groups with/without extra-articular features. This is in line with the previous studies suggesting a role for K. pneumoniae in the pathogenesis of AS.

[A child with iritis due to Chlamydia pneumoniae infection].

A case of uncommon iritis due to Chlamydia pneumoniae (C. pneumoniae) is reported. The patient was a 9-year-old boy who had suffered from cough, pharyngeal pain, and low grade fever. The symptoms persisted for more than 1 month in spite of an oral cephem antibiotic. Ophthalmalgia, congestion around the iris and cough had lasted with alleviation and exacerbation. A diagnosis of C. pneumoniae infection was made by specific polymerase chain reaction (PCR) method and microimmunofluorescence test (MIF). The symptoms subsided with administration of clarithromycin (CAM: 300 mg/day) for 2 weeks. Because of the simultaneous alleviation of iritis, C. pneumoniae infection was considered to introduce the iritis. Much remains to be clarified about this pathogenesis of iritis and more detailed evaluations are required.

Intraocular blastomycosis: case report and review.

Intraocular infection due to Blastomyces dermatitidis is rare, and only 10 cases have previously been reported. Manifestations of ocular blastomycosis can range from keratitis to panophthalmitis, and it is often difficult to diagnose ocular blastomycosis early. We report the case of a 45-year-old man who had disseminated blastomycosis that involved the lungs, skin, and ocular uvea and who was successfully treated with systemic and local antifungal therapy. We also review the literature describing the spectrum of clinical findings due to intraocular blastomycosis.

An unusual manifestation of Chlamydia pneumoniae infection: meningitis, hepatitis, iritis and atypical erythema nodosum.

A 37-year-old man was admitted to hospital with fever, muscle tenderness, headache and mild exanthema on the right thigh. During his hospital stay, the headache worsened and aseptic meningitis was diagnosed. A bilateral iritis developed, and the exanthema developed into an atypical erythema nodosum. In liver function tests, pathological results were recorded. Vasculitis was suspected but could not be confirmed. All serological tests proved negative except for a fourfold titre rise to Chlamydia pneumoniae. We concluded that the meningitis, hepatitis, iritis and atypical erythema nodosum were most probably due to a C. pneumoniae infection.

An ocular model of adenovirus type 5 infection in the NZ rabbit.

Ocular adenoviral infections occur worldwide, and currently, there is no ocular animal model for evaluating new antivirals or studying pathogenesis. With a paired-eye design, an ocular model was developed in 32 New Zealand rabbits following topical and intrastromal inoculation with a clinical isolate of adenovirus type 5 (Ad5 McEwen). Clinical signs of infection--conjunctivitis, corneal edema, subepithelial infiltrates, and iritis--and seroconversion were evaluated. Replicating virus on the ocular surface was determined by serial ocular titers. Reproducible acute ocular infection was demonstrated in 32 of 32 infected eyes (100%), with mean viral replication lasting for 8.3 days. Peak ocular viral titers (10(3) plaque forming units/ml) were achieved on day three after inoculation and represented a 2 log increase (100 times) over day one. Ocular viral replication was associated with acute conjunctivitis (24/34 eyes, 75%), and delayed-onset presumed immune-mediated clinical disease was associated with: blepharoconjunctivitis (21/32 eyes, 66%), iritis (29/32 eyes, 91%), corneal edema (32/32 eyes, 100%), and subepithelial corneal infiltrates (30/32 eyes, 94%). Seroconversion was demonstrated in 26 of 31 rabbits (84%). The study concludes that a potentially useful animal model of adenoviral ocular infection can be attained.

Histoplasma capsulatum endophthalmitis after cataract extraction.

A 60-year-old white man from an area endemic for Histoplasma capsulatum presented with a vitreous wick, hypopyon iritis, and dense vitreitis 2 months after removal of an anterior chamber intraocular lens (IOL) for chronic iritis. A diagnostic vitrectomy was performed and H. capsulatum was cultured and identified 2 weeks later. Despite intravitreal and intravenous amphotericin as well as repeat vitrectomies, the inflammation worsened and the eye was removed. Results of histopathologic examination showed Histoplasma organisms along the vitreous wick, over the surface of the iris and ciliary body, and over the retina. No organisms were found in the choroid. Dalen-Fuchs-type nodules similar to those of sarcoid also were noted, but there was no evidence of granulomatous inflammation in the uvea. Because of his unilateral disease with Histoplasma in the vitreous wick, negative serology, and an absence of systemic infection, the authors believe that this patient had a previously unreported form of ocular Histoplasma, exogenous postoperative Histoplasma endophthalmitis.

Histopathological findings in the iris of dapsone treated leprosy patients.

From 43 Nepalese leprosy patients skin smear negative, and treated with dapsone (diamino diphenyl sulphone), and without any sign of active leprosy or iritis, specimens from iridectomy during cataract surgery were studied histopathologically. Of 49 iris specimens only six (12%) were found to be without any histopathological change. Atrophy of the iris stroma was seen in 63% and neovascularisation in 6% of all cases. In 16% in which the dilator muscle could be detected, it was atrophic, and in 11% the pigmented epithelium was thinned and atrophic. Cellular inflammatory infiltrations were seen in 88% of all specimens. They were mostly slight in eyes which before operation had been without posterior synechiae of the iris. In most of the eyes in which posterior synechiae had been present moderate or heavy inflammatory cell infiltrates composed of lymphocytes and plasma cells, often associated with macrophages, neutrophils, or eosinophils, were found. In five iris specimens acid fast bacilli were present. This raises the question whether these can survive systemically despite dapsone chemotherapy in the iris, thus leading to dapsone-resistant leprosy and to recurrent iritis.

HSV-1 recovery from ocular tissues after viral inoculation into the superior cervical ganglion.

New Zealand albino rabbits were inoculated in the right superior cervical ganglion with 25 microliter of herpes simplex virus type 1 (HSV-1) (McKrae strain; 10(3) or 10(5) PFU/ml). Positive tear film swabs were detected at least once in 28/32 (88%) of ipsilateral eyes and 6/32 (19%) of contralateral eyes beginning on postinoculation (PI) day 2-6. The average HSV-1 titer in the tear film was 4.0 X 10(3) PFU in ipsilateral eyes and 2.7 X 10(3) PFU in contralateral eyes, determined from eye washes after inoculation of 25 PFU of HSV-1. In selected rabbits, the aqueous humor was positive for virus on PI days 3, 4, 5, 6, and 8. the aqueous humor in ipsilateral eyes showed positive results in 9/11 (82%) of the eyes tapped on PI 3, 13/18 (72%) on PI 4, 5/11 (45%) on PI 5, 1/6 (17%) on PI 6, and 1/2 (50%) on PI 8. No virus was detected in aqueous humor tappings in any contralateral eyes (0/65). Conjunctivitis and iritis (iris hyperemia) appeared in all ipsilateral eyes beginning as early as PI day 1. Conjunctivitis occurred in 1/21 (4.8%) of contralateral eyes. Cells and flare appeared in 18/21 (86%) of ipsilateral eyes and 2/21 (9.5%) of contralateral eyes. Hyphema was noted in 3/21 (14%) of ipsilateral eyes. Of the eyes with iritis, 12/21 (57%) developed corneal edema. Corneal dendritic ulcers were observed in 4/21 (19%) of ipsilateral eyes and 2/21 (9.5%) of contralateral eyes. No ocular fundus changes were seen in any contralateral or ipsilateral eyes.(ABSTRACT TRUNCATED AT 250 WORDS)

Idoxuridine ocular insert therapy. Use in treatment of experimental Herpes simplex keratitis.

Therapy of acute Herpes simplex keratitis in rabbits with idoxuridine-releasing ocular inserts showed that an application rate of 30mug/hr gave significantly better results than conventional treatment with idoxuridine drops and ointment while exposing the eye to 40% less drug. Delivery rates lower than this were equal or not as effective as drop and ointment therapy and rates up to 100 mug/hr did not produce significantly better results than rates of 30mug/hr. Serial viral cultures demonstrated the persistence of virus beyond the period of clinical resolution of disease in all treatment groups, indicating that therapy should be continued longer than apparent resolution of disease.

Ocular pathogenicity of types 1 and 2 Herpesvirus hominis in rabbits.

Type 2 strains of Herpesvirus hominis produced more severe lesions in rabbit corneas than type 1 strains.