Immunity to pathogenic fungi in the eye.

Fusarium, Aspergillus and Candida are important fungal pathogens that cause visual impairment and blindness in the USA and worldwide. This review will summarize the epidemiology and clinical features of corneal infections and discuss the immune and inflammatory responses that play an important role in clinical disease. In addition, we describe fungal virulence factors that are required for survival in infected corneas, and the activities of neutrophils in fungal killing, tissue damage and cytokine production.

Predatory bacteria prevent the proliferation of intraocular Serratia marcescens and fluoroquinolone-resistant Pseudomonas aeruginosa.

Endogenous endophthalmitis caused by Gram-negative bacteria is an intra-ocular infection that can rapidly progress to irreversible loss of vision. While most endophthalmitis isolates are susceptible to antibiotic therapy, the emergence of resistant bacteria necessitates alternative approaches to combat intraocular bacterial proliferation. In this study the ability of predatory bacteria to limit intraocular growth of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus was evaluated in a New Zealand white rabbit endophthalmitis prevention model. Predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus were able to reduce proliferation of keratitis isolates of P. aeruginosa and to a lesser extent S. marcescens. However, it was not able to significantly reduce the number of intraocular S. aureus, which is not a productive prey for these predatory bacteria, suggesting that the inhibitory effect on P. aeruginosa and S. marcescens requires active predation rather than an antimicrobial immune response. Similarly, UV-inactivated B. bacteriovorus were unable to prevent proliferation of P. aeruginosa. Together, these data indicate in vivo inhibition of Gram-negative bacteria proliferation within the intra-ocular environment by predatory bacteria.

[Distribution and Antibiotic Resistance Analysis of Ocular Bacterial Pathogens at a Tertiary Hospital From 2012 to 2021]. / 某三甲医院2012­2021å¹´çœ¼éƒ¨ç»†èŒæ„ŸæŸ“ç— åŽŸèŒåˆ†å¸ƒåŠè€è¯æ€§åˆ†æž.

Objective: To analyze the distribution of ocular bacterial pathogens and their antibiotic resistance status at a tertiary-care hospital and to provide a reference for the appropriate use of antibiotics. Methods: Retrospective analysis was conducted with bacteria isolated from the ophthalmic samples sent for lab analysis at a tertiary-care hospital from 2012 to 2021. The suspected bacterial strains were identified with automated systems for microbial identification and susceptibility analysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. VITEK 2 Compact, an automated microbial identification and antibiotic susceptibility analysis system, was used for antimicrobial susceptibility testing. Results: A total of 1556 ophthalmology bacteria culture samples were collected, 574 of which showed bacterial growth, presenting an overall positive rate of 36.89%. Of the isolated bacteria, Gram-positive cocci, Gram-positive bacilli, Gram-negative bacilli, and Gram-negative cocci accounted for 63.15% (377/597), 18.76% (112/597), 17.09% (102/597), and 1.00% (6/597), respectively. Among the bacteria isolated in different years over the course of a decade, Gram-positive cocci always turned out to be the main cause of eye infections. Of the Gram-positive cocci, 73.47% (277/377) were isolated from patients with endophthalmitis, with the most important species being Staphylococcus epidermidis, which was followed by Streptococcus viridans. The rest, or 26.53% (100/377), of the Gram-positive cocci were isolated from patients with external eye infections, with the main isolated strains being Staphylococcus epidermidis, Streptococcus viridans, and Staphylococcus aureus. More than 70% of Staphylococcus epidermidis isolated from both endophthalmitis and external eye infections were resistant to methicillin. No strains resistant to vancomycin, linezolid, or tigecycline were detected. Staphylococcus epidermidis isolated from patients with external eye infections had a low rate of resistance to levofloxacin (2/27 or 7.41%), whereas those isolated from patients with endophthalmitis had a higher resistance rate (43/127 or 33.86%). The difference in drug resistance rate between the two groups was statistically significant (P<0.05). Conclusion: The chief ocular bacterial pathogens identified in a tertiary-care hospital were Gram-positive cocci, among which, Staphylococcus epidermidis was the most common species. The Staphylococcus epidermidis identified in the hospital had a high rate of resistance to oxacillin, but remained highly sensitive to vancomycin, linezolid, and tigecycline. The endophthalmitis caused by Staphylococcus epidermidis in the hospital can be treated empirically with vancomycin and then the treatment plan can be further adjusted according to the results of the drug susceptibility test. However, the establishment of the breakpoint of drug susceptibility test is mainly based on the model of bloodstream infection and has limited reference value for the treatment of eye infection. The required drug distribution concentration at the infection site can be achieved by dose increase or local administration.

Rubella virus-associated uveitis at a tertiary care hospital in Germany between 2013 and 2019.

Uveitis is a process of intraocular inflammation that may involve different sections of the uveal tract. Apart from systemic or localized immune-mediated diseases, infections are key players in the etiology of uveitis and entail different treatment strategies. Rubella virus (RuV) is a recognized causative agent for the development of Fuchs uveitis, representing a major cause of virus-associated intraocular inflammation. A cohort of 159 patients diagnosed with different forms of uveitis between 2013 and 2019 was subjected to diagnostic antibody testing of the aqueous or vitreous humor. The diagnostic panel included RuV, cytomegalovirus, herpes simplex virus, varicella-zoster virus, and toxoplasmosis. Within this cohort, 38 RuV-associated uveitis (RAU) patients were identified based on a pathologic Goldman-Witmer coefficient indicative of an underlying RuV infection. With a mean age of 45.9 years, the RAU patients were younger than the non-RAU patients (56.3, p < 0.001). The evaluation of clinical parameters revealed a predominance of anterior uveitis and late sequalae such as cataract and glaucoma among the RAU patients. In 15 of the patients a history of prior RuV infections could be confirmed. The study underlines the importance of long-term surveillance of RuV associated diseases that originate from infections before the introduction of RuV vaccination programs.

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections.

The variety and complexity of ocular infections have increased significantly in the last decade since the publication of Cumitech 13B, Laboratory Diagnosis of Ocular Infections (L. D. Gray, P. H. Gilligan, and W. C. Fowler, Cumitech 13B, Laboratory Diagnosis of Ocular Infections, 2010). The purpose of this practical guidance document is to review, for individuals working in clinical microbiology laboratories, current tools used in the laboratory diagnosis of ocular infections. This document begins by describing the complex, delicate anatomy of the eye, which often leads to limitations in specimen quantity, requiring a close working bond between laboratorians and ophthalmologists to ensure high-quality diagnostic care. Descriptions are provided of common ocular infections in developed nations and neglected ocular infections seen in developing nations. Subsequently, preanalytic, analytic, and postanalytic aspects of laboratory diagnosis and antimicrobial susceptibility testing are explored in depth.

Roles of CCL2 and CCL3 in intraocular inflammation during Bacillus endophthalmitis.

Bacillus cereus (B. cereus) endophthalmitis is a vision-threatening bacterial infection. Uncontrolled inflammatory responses are the hallmark of this disease which cause irreversible damage to the retina. We recently reported C-X-C chemokines as a vital modulators which impacted the pathogenesis of this disease. Here, we investigated the impact of two highly upregulated C-C chemokines, CCL2 and CCL3, on intraocular inflammation this disease. B. cereus was injected into the eyes of C57BL/6J (WT), CCL2-/-, and CCL3-/- mice to induce endophthalmitis. Infected eyes were examined for bacterial growth, retinal function, and inflammation. Bacterial growth in CCL2-/- and CCL3-/- mice were similar, but retained retinal function was greater in CCL2-/- and CCL3-/- eyes compared to that of C57BL/6J eyes. The retinal architecture of infected eyes of CCL2-/- mice were conserved for a longer period of time than in infected CCL3-/- eyes. Infected CCL2-/- and CCL3-/- eyes had less inflammation than did infected C57BL/6J eyes. Based on these results, we assessed the efficacies of intravitreal anti-CCL2 or anti-CCL3 with or without the antibiotic gatifloxacin. Compared to infected untreated eyes, there was significantly less inflammation and greater retention of retinal function in eyes treated with anti-CCL2 or anti-CCL3 with gatifloxacin. This study showed that B. cereus endophthalmitis in CCL2-/- mice had a better clinical outcome than in CCL3-/- mice. Intravitreal administration of anti-CCL2 and anti-CCL3 with gatifloxacin significantly reduced inflammation and provided protection of retinal function. These results suggest that CCL2 and CCL3 are prospective anti-inflammatory targets that should be tested along with other antibiotics for treating Bacillus and perhaps other forms of endophthalmitis.

Ocular transmissibility of COVID-19: possibilities and perspectives.

Since the initial outbreak of coronavirus disease 2019 (COVID-19), extensive research has emerged from across the globe to understand the pathophysiology of this novel coronavirus. Transmission of this virus is a subject of particular interest as researchers work to understand which protective and preventative measures are most effective. Despite the well understood model of aerosol-respiratory mediated transmission, the exact mechanism underlying the inoculation, infection and spread of COVID-19 is currently unknown. Given anatomical positioning and near constant exposure to aerosolized pathogens, the eye may be a possible gateway for COVID-19 infection. This critical review explores the possibility of an ocular-systemic or ocular-nasal-pulmonic pathway of COVID-19 infection and includes novel insights into the possible immunological mechanisms leading to cytokine surge.

The protective effect of URP20 on ocular Staphylococcus aureus and Escherichia coli infection in rats.

BACKGROUND: Infectious keratitis, a medical emergency with acute and rapid disease progression may lead to severe visual impairment and even blindness. Herein, an antimicrobial polypeptide from Crassostrea hongkongensis, named URP20, was evaluated for its therapeutic efficacy against keratitis caused by Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) infection in rats, respectively. METHODS: A needle was used to scratch the surface of the eyeballs of rats and infect them with S. aureus and E.coli to construct a keratitis model. The two models were treated by giving 100 µL 100 µM URP20 drops. Positive drugs for S. aureus and E. coli infection were cefazolin eye drops and tobramycin eye drops, respectively. For the curative effect, the formation of blood vessels in the fundus was observed by a slit lamp (the third day). At the end of the experiment, the condition of the injured eye was photographed by cobalt blue light using 5 µL of 1% sodium fluorescein. The pathological damage to corneal tissues was assessed using hematoxylin-eosin staining, and the expression level of vascular endothelial growth factor (VEGF) was detected by immunohistochemistry. RESULTS: URP20 alleviated the symptoms of corneal neovascularization as observed by slit lamp and cobalt blue lamp. The activity of S. aureus and E.coli is inhibited by URP20 to protect corneal epithelial cells and reduce corneal stromal bacterial invasion. It also prevented corneal thickening and inhibited neovascularization by reducing VEGF expression at the cornea. CONCLUSION: URP20 can effectively inhibit keratitis caused by E.coli as well as S. aureus in rats, as reflected by the inhibition of corneal neovascularization and the reduction in bacterial damage to the cornea.

Simultaneous Determination of Moxifloxacin Hydrochloride and Dexamethasone Sodium Phosphate in Rabbit Ocular Tissues and Plasma by LC-MS/MS: Application for Pharmacokinetics Studies.

Treatment of ocular infection involves pharmacotherapy with steroids and antibiotic drops, such as moxifloxacin hydrochloride (MFH) and dexamethasone sodium phosphate (DSP). To characterize the pharmacokinetics of these two compounds, we performed and validated a liquid chromatography-mass spectrometry (LC-MS/MS) method to quantify them in rabbit ocular tissues and plasma. We used protein precipitation to extract the compounds. The analyte and internal standard (IS) were separated using a Shim-pack Scepter C18 column. The mobile phase was composed of 0.1% formic acid water (A) and methanol (B). MFH and DSP were detected using positive ion electrostatic ionization (ESI) in multiple reaction monitoring mode (MRM). The calibration curves for both compounds showed good linearity over concentrations ranging from 0.5 to 200 ng/mL in rabbit ocular tissues and plasma. The lower limit of quantification for both MFH and DSP was 0.5 ng/mL. We validated this method for selectivity, linearity (r2 > 0.99), precision, accuracy, matrix effects, and stability. Thus, we used this method to assess the pharmacokinetic (PK) characteristics of MFH and DSP in rabbit ocular tissues and plasma after single doses. Our results indicate that this method can be used for the simultaneous analysis of moxifloxacin hydrochloride and dexamethasone sodium phosphate in clinical samples.

A Case of Ocular Sparganosis in China: Episode of Migration from Muscle Cone to Subconjunctiva.

To improve our understanding of the migration of sparganum in humans, we report a case of ocular sparganosis having the migratory episode from the muscle cone to the subconjunctiva. A 34-year-old woman was admitted to the Hospital of Anhui Medical University (Hefei, China), in December 2019. She presented with conjunctival hemorrhage and recurrent pain in the left eye. A foreign body was found in the muscle cone of the eye. Two months later, a ribbon-like white material was found under the conjunctiva on slit-lamp examination. A long and slender, actively moving parasite was extracted by surgery. The extracted worm was approximately 8 cm long and 2 mm wide. The worm was whitish, wrinkled, ribbon shaped, and had a slightly enlarged scolex. The worm sample was morphologically identified as a plerocercoid larva (sparganum) of the Spirometra tapeworm. Her conjunctival blood suffusion and eye pain ceased within 1 week after operation. She has been in good health without any symptoms during the 2-year follow-up. A case of ocular sparganosis, in which larval worm migrated from the muscle cone to the subconjunctiva is reported from China.

Expression of Murine CD80 by Herpes Simplex Virus 1 in Place of Latency-Associated Transcript (LAT) Can Compensate for Latency Reactivation and Anti-apoptotic Functions of LAT.

High rates of wild-type (WT) herpes simplex virus 1 (HSV-1) latency reactivation depend on the anti-apoptotic activities of latency-associated transcript (LAT). Replacing LAT with the baculovirus inhibitor of apoptosis protein (cpIAP) or cellular FLIP (FLICE-like inhibitory protein) gene restored the WT latency reactivation phenotype to that of a LAT-minus [LAT(-)] virus, while similar recombinant viruses expressing interleukin-4 (IL-4) or interferon gamma (IFN-γ) did not. However, HSV-1 recombinant virus expressing cpIAP did not restore all LAT functions. Recently, we reported that a similar recombinant virus expressing CD80 in place of LAT had higher latency reactivation than a LAT-null virus. The present study was designed to determine if this CD80-expressing recombinant virus can restore all LAT functions as observed with WT virus. Our results suggest that overexpression of CD80 fully rescues LAT function in latency reactivation, apoptosis, and immune exhaustion, suggesting that LAT and CD80 have multiple overlapping functions.IMPORTANCE Recurring ocular infections caused by HSV-1 can cause corneal scarring and blindness. A major function of the HSV-1 latency-associated transcript (LAT) is to establish high levels of latency and reactivation, thus contributing to the development of eye disease. Here, we show that the host CD80 T cell costimulatory molecule functions similarly to LAT and can restore the ability of LAT to establish latency, reactivation, and immune exhaustion as well as induce the expression of caspase 3, caspase 8, caspase 9, and Bcl2. Our results suggest that, in contrast to several other previously tested genes, CD80-expressing virus can completely compensate for all known and tested LAT functions.

High Frequency of Gamma Interferon-Producing PLZFloRORγtlo Invariant Natural Killer 1 Cells Infiltrating Herpes Simplex Virus 1-Infected Corneas Is Associated with Asymptomatic Ocular Herpesvirus Infection.

Invariant natural killer (iNKT) cells are among the first innate immune cells to elicit early protective immunity that controls invading viral pathogens. The role of the iNKT cell subsets iNKT1, iNKT2, and iNKT17 in herpesvirus immunity remains to be fully elucidated. In this study, we examined the protective role of cornea-resident iNKT cell subsets using the mouse model of ocular herpesvirus infection and disease. Wild-type (WT) C57BL/6 (B6) mice and CD1d knockout (KO) mice were infected ocularly with herpes simplex virus 1 (HSV-1) (strain McKrae). Cornea, spleen, and liver were harvested at 0, 2, 5, 8, and 14 days postinfection (p.i.), and the frequency and function of the three major iNKT cell subsets were analyzed and correlated with symptomatic and asymptomatic corneal herpesvirus infections. The profiles of 16 major pro- and anti-inflammatory cytokines were analyzed in corneal lysates using Western blot and Luminex assays. Early during ocular herpesvirus infection (i.e., day 2), the gamma interferon (IFN-γ)-producing PLZFloRORγtlo (promyelocytic leukemia zinc finger, retinoic acid-related orphan receptor gT) iNKT1 cell subset was the predominant iNKT cell subset in infected asymptomatic corneas. Moreover, compared to the asymptomatic corneas of HSV-1-infected WT mice, the symptomatic corneas CD1d KO mice, with iNKT cell deficiency, had increased levels of the inflammatory cytokine interleukin-6 (IL-6) and decreased levels of IL-12, IFN-γ, and the JAK1, STAT1, NF-κB, and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways. Our findings suggest that IFN-γ-producing PLZFloRORγtlo iNKT1 cells play a role in the protective innate immune response against symptomatic ocular herpes.IMPORTANCE We investigated the protective role of iNKT cell subsets in asymptomatic ocular herpesvirus infection. We found that early during ocular herpesvirus infection (i.e., on day 2 postinfection), IFN-γ-producing PLZFloRORγtlo iNKT1 cells were the predominant iNKT cell subset in infected corneas of asymptomatic B6 mice (with little to no corneal herpetic disease), compared to corneas of symptomatic mice (with severe corneal herpetic disease). Moreover, compared to asymptomatic corneas of wild-type (WT) B6 mice, the symptomatic corneas of CD1d KO mice, which lack iNKT cells, showed (i) decreases in the levels of IFN-γ and IL-12, (ii) an increase in the level of the inflammatory cytokine IL-6; and (iii) downregulation of the JAK1, STAT1, NF-κB, and ERK1/2 pathways. The findings suggest that early during ocular herpesvirus infection, cornea-resident IFN-γ-producing PLZFloRORγtlo iNKT1 cells provide protection from symptomatic ocular herpes.

Restoring Herpesvirus Entry Mediator (HVEM) Immune Function in HVEM-/- Mice Rescues Herpes Simplex Virus 1 Latency and Reactivation Independently of Binding to Glycoprotein D.

The immune modulatory protein herpes virus entry mediator (HVEM) is one of several cellular receptors used by herpes simplex virus 1 (HSV-1) for cell entry. HVEM binds to HSV-1 glycoprotein D (gD) but is not necessary for HSV-1 replication in vitro or in vivo Previously, we showed that although HSV-1 replication was similar in wild-type (WT) control and HVEM-/- mice, HSV-1 does not establish latency or reactivate effectively in mice lacking HVEM, suggesting that HVEM is important for these functions. It is not known whether HVEM immunomodulatory functions contribute to latency and reactivation or whether its binding to gD is necessary. We used HVEM-/- mice to establish three transgenic mouse lines that express either human WT HVEM or human or mouse HVEM with a point mutation that ablates its ability to bind to gD. Here, we show that HVEM immune function, not its ability to bind gD, is required for WT levels of latency and reactivation. We further show that HVEM binding to gD does not affect expression of the HVEM ligands BTLA, CD160, or LIGHT. Interestingly, our results suggest that binding of HVEM to gD may contribute to efficient upregulation of CD8α but not PD1, TIM-3, CTLA4, or interleukin 2 (IL-2). Together, our results establish that HVEM immune function, not binding to gD, mediates establishment of latency and reactivation.IMPORTANCE HSV-1 is a common cause of ocular infections worldwide and a significant cause of preventable blindness. Corneal scarring and blindness are consequences of the immune response induced by repeated reactivation events. Therefore, HSV-1 therapeutic approaches should focus on preventing latency and reactivation. Our data suggest that the immune function of HVEM plays an important role in the HSV-1 latency and reactivation cycle that is independent of HVEM binding to gD.

Pathobiology and treatment of viral keratitis.

Keratitis is one of the most prevalent ocular diseases manifested by partial or total loss of vision. Amongst infectious (viz., microbes including bacteria, fungi, amebae, and viruses) and non-infectious (viz., eye trauma, chemical exposure, and ultraviolet exposure, contact lens) risk factors, viral keratitis has been demonstrated as one of the leading causes of corneal opacity. While many viruses have been shown to cause keratitis (such as rhabdoviruses, coxsackieviruses, etc.), herpesviruses are the predominant etiologic agent of viral keratitis. This chapter will summarize current knowledge on the prevalence, diagnosis, and pathobiology of viral keratitis. Virus-mediated immunomodulation of host innate and adaptive immune components is critical for viral persistence, and dysfunctional immune responses may cause destruction of ocular tissues leading to keratitis. Immunosuppressed or immunocompromised individuals may display recurring disease with pronounced severity. Early diagnosis of viral keratitis is beneficial for disease management and response to treatment. Finally, we have discussed current and emerging therapies to treat viral keratitis.

Characterization of antibiotic resistance and virulence genes of ocular methicillin-resistant Staphylococcus aureus strains through complete genome analysis.

Virulence-factor encoding genes (VFGs) and antimicrobial resistance genes (ARGs) of ocular Methicillin-Resistant Staphylococcus aureus (MRSA), are the reason behind the common cause of severe and untreatable ocular infection and are largely unknown. The unavailability of the complete genome sequence of ocular MRSA strains hinders the unambiguous determination of ARGs and VRGs role in disease pathogenesis and their genomic location. To fulfill this critical need, we achieved the high-quality complete genome of four ocular MRSA strains (AMRF3 - AMRF6) by combining MinION nanopore sequencing technology, followed by polishing with Illumina sequence reads. We obtained a single chromosome and a plasmid in each strain. Sequence typing revealed that AMRF3 and AMRF5 strains harbored ST772, whereas AMRF4 and AMRF6 harbored ST 2066. All plasmids carried heavy metal cadmium resistance genes cadC and cadD, while cadA was detected only in the plasmid pSaa6159 of AMRF4 and AMRF6 strains. Further, pSaa6159 contains a complete Tn552 transposon with beta-lactamase genes, blaI, blaR1, and blaZ. Interestingly, pSaa6159 in AMRF6 carried five copies of Tn552 transposon. Several exotoxins and enterotoxins were identified across ocular MRSA strains and ST2066 strains found to be not carried any enterotoxins; this finding suggests that these two strains are exotoxigenic. Besides, ST2066 strains carried serine proteases (splA, splB, splD, splE and spIF) and exotoxin (seb and set 21) for their virulence, while ST772 carried antimicrobial resistance genes (blaZ, dfrG, msrA, mphC and fosB) and enterotoxin sec for virulence, suggesting sequence type-specific resistance and virulence. Also, we identified many VFGs and ARGs, that provided multi-drug resistance, enterotoxigenic, exotoxigenic, biofilm-forming, host tissue adhesion and immune response evasion in ocular MRSA strains. Thus, our study provides a better insight into the genomes of ocular MRSA strains that would provide more effective treatment strategies for ocular MRSA infection.

Corynebacterium ocular infection after Baerveldt glaucoma implant surgery: treatment involving immediate tube withdrawal and temporary subconjunctival tube placement: a case report.

BACKGROUND: We report a case of Corynebacterium endophthalmitis secondary to tube exposure following Baerveldt glaucoma implant surgery that was successfully treated with prompt tube withdrawal and temporary subconjunctival tube placement without removing the glaucoma drainage device. CASE PRESENTATION: A 65-year-old Japanese man with secondary glaucoma underwent glaucoma drainage device surgery with a donor scleral patch graft in the inferonasal quadrant of his right eye. Ten months after surgery, he presented with tube exposure due to dehiscence of the overlying conjunctiva and erosion of the scleral patch graft. Eleven days later, mild inflammation was found in the anterior chamber and anterior vitreous body, with the root of the tube surrounded by a plaque at the site of insertion in the anterior chamber. He was diagnosed with infectious endophthalmitis secondary to tube exposure. Two days later, since medical therapy was ineffective, the tube was withdrawn from the anterior chamber and irrigated with a polyvinyl alcohol-iodine solution, and the tube was tucked into the subconjunctival space. Complete resolution of the infection was achieved 1.5 months later. The tube was reinserted nasally into the anterior chamber and covered with a scleral patch graft and a free limbal conjunctival autograft. Thereafter, there has been no recurrence of infection or tube exposure. Twenty eight months after tube reinsertion, his right best-corrected visual acuity was 20/50 and intraocular pressure was 12 mmHg. CONCLUSION: Prompt tube withdrawal and temporary subconjunctival tube placement followed by tube reinsertion may be effective for endophthalmitis associated with tube exposure after glaucoma drainage device surgery.

The first case of periorbital human dirofilariasis in the Czech Republic.

Dirofilaria repens and Dirofilaria immitis are the most common filarial species affecting humans in Europe. Dirofilaria repens causes subcutaneous or ocular infection, whereas D. immitis is responsible mainly for the pulmonary form. In this report, we present the first human case of periorbital dirofilariasis in the Czech Republic. A 58-year-old woman suffered from an eyelid oedema, redness and pain in the left eye. After excising the parasite from her eyelid, all clinical symptoms disappeared. Based on the morphology and cytochrome oxidase I sequencing, the parasite was identified as D. repens. Histology revealed that the excised worm was female with absent microfilariae in uteri. With respect to the length of the incubation period and the sequence identity with a known Czech isolate, we concluded that D. repens was most likely of autochthonous origin.

Absence of Signal Peptide Peptidase, an Essential Herpes Simplex Virus 1 Glycoprotein K Binding Partner, Reduces Virus Infectivity In Vivo.

We previously reported that herpes simplex virus (HSV) glycoprotein K (gK) binds to signal peptide peptidase (SPP), also known as minor histocompatibility antigen H13. Binding of gK to SPP is required for HSV-1 infectivity in vitro SPP is a member of the γ-secretase family, and mice lacking SPP are embryonic lethal. To determine how SPP affects HSV-1 infectivity in vivo, the SPP gene was deleted using a tamoxifen-inducible Cre recombinase driven by the ubiquitously expressed ROSA26 promoter. SPP mRNA was reduced by more than 93% in the cornea and trigeminal ganglia (TG) and by 99% in the liver of tamoxifen-injected mice, while SPP protein expression was reduced by 90% compared to the level in control mice. Mice lacking SPP had significantly less HSV-1 replication in the eye as well as reduced gK, UL20, ICP0, and gB transcripts in the cornea and TG compared to levels in control mice. In addition, reduced infiltration of CD45+, CD4+, CD8+, F4/80+, CD11c+, and NK1.1+ T cells was observed in the cornea and TG of SPP-inducible knockout mice compared to that in control mice. Finally, in the absence of SPP, latency was significantly reduced in SPP-inducible knockout mice compared to that in control mice. Thus, in this study we have generated SPP-inducible knockout mice and shown that the absence of SPP affects virus replication in the eye of ocularly infected mice and that this reduction is correlated with the interaction of gK and SPP. These results suggest that blocking this interaction may have therapeutic potential in treating HSV-1-associated eye disease.IMPORTANCE Glycoprotein K (gK) is an essential and highly conserved HSV-1 protein. Previously, we reported that gK binds to SPP, an endoplasmic reticulum (ER) protein, and blocking this binding reduces virus infectivity in vitro and also affects gK and UL20 subcellular localization. To evaluate the function of gK binding to SPP in vivo, we generated SPP-inducible knockout mice and observed the following in the absence of SPP: (i) that significantly less HSV-1 replication was seen in ocularly infected mice than in control mice; (ii) that expression of various HSV-1 genes and cellular infiltrates in the eye and trigeminal ganglia of infected mice was less than that in control mice; and (iii) that latency was significantly reduced in infected mice. Thus, blocking of gK binding to SPP may be a useful tool to control HSV-1-induced eye disease in patients with herpes stromal keratitis (HSK).

Contribution of anti-inflammatory and anti-virulence effects of azithromycin in the treatment of experimental Staphylococcus aureus keratitis.

BACKGROUND: We aimed to demonstrate the contribution of anti-inflammatory and anti-virulence effects of azithromycin (AZM) in ocular surface infection treatment. METHODS: Staphylococcus aureus was injected into the corneal stroma of rabbits to induce keratitis. AZM at concentrations of 0.01, 0.1, and 1% was instilled into the eye twice daily. The eyes were examined using a slit lamp and scored. The viable bacteria in the cornea were counted at 48 h post infection. To evaluate the anti-inflammatory efficacy of AZM, S. aureus culture supernatant-induced anterior ocular inflammation in rabbit was examined using a slit lamp and scored. To evaluate the inhibitory effect of AZM on bacterial toxin production, S. aureus was cultured with AZM and hemolytic reaction in the culture supernatant was determined. RESULTS: In the bacterial keratitis model, AZM dose-dependently inhibited the increase in the clinical score. The viable bacterial count in the cornea treated with 1% AZM significantly decreased compared with that of the vehicle, whereas bacterial count in 0.01 and 0.1% AZM-treated corneas was similar to that of the vehicle. In the anterior ocular inflammation model, 0.1 and 1% AZM inhibited the increase in the clinical score. AZM inhibited hemolytic reaction at concentrations that did not inhibit bacterial growth. CONCLUSIONS: The results demonstrated that AZM has not only anti-bacterial, but also anti-inflammatory effects, and inhibits bacterial toxin production leading to ocular surface damage in bacterial infection. Thus, the therapeutic effect of AZM against ocular infections is expected to be higher than that which could be assumed if it only had anti-bacterial activity.

Trachoma in 3 Amerindian Communities, Venezuelan Amazon, 2018.

Trachoma is among the most common infectious causes of blindness. During January-May 2018, a total of 4 trachoma cases were diagnosed among Amerindians of the Yanomami ethnic group in 3 communities of southern Venezuela. This country has social and environmental conditions conducive to the endemicity of this neglected tropical disease.