[Bacterial endogenous endophthalmitis : Spectrum of pathogens and drug therapy]

Endogenous endophthalmitis represents an ophthalmological emergency requiring immediate diagnostics and treatment. Pathogens should be detected using appropriate methods, such as the Freiburg endophthalmitis set. In bacterial endophthalmitis both Gram-positive and Gram-negative bacteria can be detected. Frequent underlying sources include endocarditis, gastrointestinal or urogenital surgery, indwelling venous catheters, liver abscesses, skin or soft tissue infections, meningitis or less commonly, intravenous drug abuse. The treatment consists of systemic and intraocular administration of antibiotics and vitrectomy. Systemic or intraocular corticosteroids can additionally be considered.

Portable color retinography findings in COVID-19 patients admitted to the ward

Retinal lesions, including cotton-wool exudates, microbleeds, vascular occlusions and vasculitis, occur in a minority of Coronavirus Disease-19 (COVID-19) patients. Retinal assessments using retinography can help document these lesions. The objective of this work was to identify retinal changes in patients admitted to the ward with a positive Real Time Quantitative Polymerase Chain Reaction (RT-qPCR) exam for COVID-19. A cross-sectional, observational study was carried out of patients with mild and moderate symptoms admitted to the Hospital de Base in São José do Rio Preto. The Eyer® portable retinal camera (Phelcom® Technologies) was used to evaluate 30 male and 21 female patients. The ages ranged from 21 to 83 years (mean: 47 years). Systemic arterial hypertension was identified in 21 (41.2 %) and diabetes mellitus in 12 (23.5 %) patients. Six (11.7 %) reported worsening visual acuity, however, none of these patients had ocular findings to justify this complaint. Ten patients (19.6 %) had intraretinal hemorrhages; one (1.9 %) had cotton-wool exudates and seven (13.7 %) had dilations of veins. Thirteen patients (25.4 %) had vascular tortuosity and six (11.7 %) had pathological arteriovenous crossings. Portable retinography is useful to evaluate patients admitted to isolation wards due to COVID-19. It is important to remember that some of the patients investigated had comorbidities like diabetic maculopathy and systemic arterial hypertension. Hence, some care should be taken in attributing these observations uniquely to COVID-19 infection.

Zika virus infection of retinal cells and the developing mouse eye induces host responses that contrasts to the brain and dengue virus infection

Zika virus (ZIKV) infection causes ocular and neurological pathologies with ZIKV-induction of developmental abnormalities following in utero infection a major concern. The study here has compared ZIKV and the related dengue virus (DENV) infection in the eye and brain. In vitro, both ZIKV and DENV could infect cell lines representing the retinal pigmented epithelium, endothelial cells, and Mueller cells, with distinct innate responses in each cell type. In a 1-day old mouse challenge model, both ZIKV and DENV infected the brain and eye by day 6 post-infection (pi). ZIKV was present at comparable levels in both tissues, with RNA increasing with time post-infection. DENV infected the brain, but RNA was detected in the eye of less than half of the mice challenged. NanoString analysis demonstrated comparable host responses in the brain for both viruses, including induction of mRNA for myosin light chain-2 (Mly2), and numerous antiviral and inflammatory genes. Notably, mRNA for multiple complement proteins were induced, but C2 and C4a were uniquely induced by ZIKV but not DENV. Consistent with the viral infection in the eye, DENV induced few responses while ZIKV induced substantial inflammatory and antiviral responses. Compared to the brain, ZIKV in the eye did not induce mRNAs such as C3, downregulated Retnla, and upregulated CSF-1. Morphologically, the ZIKV-infected retina demonstrated reduced formation of specific retinal layers. Thus, although ZIKV and DENV can both infect the eye and brain, there are distinct differences in host cell and tissue inflammatory responses that may be relevant to ZIKV replication and disease.

Development of anti-acanthamoebic approaches

Acanthamoeba keratitis is a sight-endangering eye infection, and causative organism Acanthamoeba presents a significant concern to public health, given escalation of contact lens wearers. Contemporary therapy is burdensome, necessitating prompt diagnosis and aggressive treatment. None of the contact lens disinfectants (local and international) can eradicate Acanthamoeba effectively. Using a range of compounds targeting cellulose, ion channels, and biochemical pathways, we employed bioassay-guided testing to determine their anti-amoebic effects. The results indicated that acarbose, indaziflam, terbuthylazine, glimepiride, inositol, vildagliptin and repaglinide showed anti-amoebic effects. Compounds showed minimal toxicity on human cells. Therefore, effects of the evaluated compounds after conjugation with nanoparticles should certainly be the subject of future studies and will likely lead to promising leads for potential applications.

Evaluation of full-length nanopore 16S sequencing for detection of pathogens in microbial keratitis

BACKGROUND

Microbial keratitis is a leading cause of preventable blindness worldwide. Conventional sampling and culture techniques are time-consuming, with over 40% of cases being culture-negative. Nanopore sequencing technology is portable and capable of generating long sequencing reads in real-time. The aim of this study is to evaluate the potential of nanopore sequencing directly from clinical samples for the diagnosis of bacterial microbial keratitis.

METHODS

Using full-length 16S rRNA amplicon sequences from a defined mock microbial community, we evaluated and benchmarked our bioinformatics analysis pipeline for taxonomic assignment on three different 16S rRNA databases (NCBI 16S RefSeq, RDP and SILVA) with clustering at 97%, 99% and 100% similarities. Next, we optimised the sample collection using an ex vivo porcine model of microbial keratitis to compare DNA recovery rates of 12 different collection methods: 21-gauge needle, PTFE membrane (4 mm and 6 mm), Isohelix™ SK-2S, Sugi® Eyespear, Cotton, Rayon, Dryswab™, Hydraflock®, Albumin-coated, Purflock®, Purfoam and Polyester swabs. As a proof-of-concept study, we then used the sampling technique that provided the highest DNA recovery, along with the optimised bioinformatics pipeline, to prospectively collected samples from patients with suspected microbial keratitis. The resulting nanopore sequencing results were then compared to standard microbiology culture methods.

RESULTS

We found that applying alignment filtering to nanopore sequencing reads and aligning to the NCBI 16S RefSeq database at 100% similarity provided the most accurate bacterial taxa assignment. DNA concentration recovery rates differed significantly between the collection methods (p < 0.001), with the Sugi® Eyespear swab providing the highest mean rank of DNA concentration. Then, applying the optimised collection method and bioinformatics pipeline directly to samples from two patients with suspected microbial keratitis, sequencing results from Patient A were in agreement with culture results, whilst Patient B, with negative culture results and previous antibiotic use, showed agreement between nanopore and Illumina Miseq sequencing results.

CONCLUSION

We have optimised collection methods and demonstrated a novel workflow for identification of bacterial microbial keratitis using full-length 16S nanopore sequencing.

Smart polymeric eye gear: A possible preventive measure against ocular transmission of COVID-19

The angiotensin-converting enzyme 2(ACE-2) receptors with approx. 0.8% congestion in conjunctival surface, leads to increase susceptibility of Covid-19 transmission through ocular surface. It has been observed that prophylactic measures such as goggle or face shield are unable to offer complete protection against ocular transmission of SRS-CoV-2. Hence, it is hypothesized that topical ocular prophylaxis using biocompatible polymers with reported in-vitro and in-vivo evidence of ACE inhibition and antiviral activity appears to be a promising strategy for preventing ocular transmission of Covid-19 to healthcare workers. They are capable of binding to ACE-2 receptors which may provide highly potential trails to block virus entry to host cells. Further biopolymers imparting antiviral activities greatly improve their protective performance. They not only provide prolong protection but also are safe for long-term use. This article discusses the description of structural and functional attributes of ACE-2 to identify appropriate polymer with better binding affinity. Furthermore, potential polymers with appropriate concentration are suggested for evaluation through a hypothesis to consider them for Covid-19 implication.

Risk of eye infections in dental personnel and the need for its prevention: a case report

A lot of dentists and dental personnel are at high risk of contracting eye infections during operative procedures involving aerosols. As many may not be aware of it, they often ignore the precautions to be taken for prevention of such infections. This is one such case report of a dental intern where an eyelid infection arose shortly after she treated a patient with an infected tooth in an operative procedure. This case report emphasizes the importance of preventive barriers for the dentist, and that how special protective gear is required for doing restorative cases which involve dealing with infection.

Management of preseptal and orbital cellulitis for the primary care physician

Preseptal cellulitis and postseptal (orbital) cellulitis represent a spectrum of orbital infections which a primary care provider and ophthalmologist may see during practice. Most often these conditions occur through spread from the sinuses, though there are a variety of other inciting factors. These conditions can both present with erythema and edema, but a complete and thorough exam can help a practitioner differentiate the two. Patients should be treated with targeting the most common pathogens and followed very closely by their providers. This article will discuss the anatomy, pathogenesis, risk factors, diagnosis, management and prognosis of preseptal and orbital cellulitis.

Delayed intraorbital infection after craniofacial bone surgery

Intraorbital infection shows a low incidence, but it might cause blindness or even death. This case is unusual in that its origin from a craniofacial bone fracture prior to infection of the maxillary sinus. A 33-year-old female patient was referred for right cheek swelling. When she visited the emergency room, we removed right cheek hematoma and bacterial examination was done. In the past, she had craniofacial bone surgical history due to a traffic accident 6 years ago. Next day, the swelling had remained with proptosis and pus was recognized in the conjunctiva. We planned an emergency operation and removed the pus which was already spread inside the orbit. And the evaluation for sinusitis was consulted to the otorhinolaryngology department simultaneously. There were Prevotella oralis and methicillin-resistant Staphylococcus epidermidis bacterial infection in the intraorbital and sinus respectively. Afterwards, the vigorous dressing was done for over a month with intravenous antibiotics. Though the intraorbital infection was resolved, blindness and extraocular movement limitation were inevitable. In conclusion, close follow up of the maxillary sinus in facial bone fracture patients is important and aggressive treatment is needed when an infection is diagnosed.

Helcococcus ovis in a patient with an artificial eye: a case report and literature review

BACKGROUND

Helcococcus ovis, belonging to the genus of Helcococcu in Peptostreptococcaceae, is one kind of facultative anaerobic and gram-positive cocci, which was first isolated from a mixed infection in sheep in 1999. To our knowledge, it's known as an invasive pathogen in animals, and never been reported as a human pathogen in published literature. The aims of this work are to describe the first report of H. ovis which was recovered from the artificial eye of human case and perform a literature review.

CASE PRESENTATION

A 26 year-old man reporting pyogenic infection with an artificial eye attended ophthalmic ward in Tongji hospital. After physical examination, clinical and laboratory investigations, the diagnosis of eye infection caused by Helcococcus ovis and Staphylococcus aureus was established. Receiving a medico-surgical approach, the patient was successfully treated. The treatment consisted in intravenous cefotaxime and ornidazole, levofloxacin eye drops during two weeks and removing of right artificial eye with debridement.

CONCLUSIONS

We describe here the first known case of H. ovis which was recovered from human artificial eye. This report different from previous data found in the literature emphasizes the invasive potential of this bacterial species as a pathogen in human. Prospectively, the application of next generation sequencing tools would contribute to a more accurate classification of clinical strains.

Periorbital infections and conjunctivitis due to Panton-Valentine Leukocidin (PVL) positive Staphylococcus aureus in children

Background

Colonisation with Panton-Valentine Leukocidin expressing strains of Staphylococcus aureus (PVL + SA) is characterised by recurrent skin and soft tissue infections. While periorbital and orbital infections are common in children and frequently caused by S. aureus the role of PVL + SA in recurrent eye infections has not been studied.

This study aimed to detect and report frequency and recurrence of periorbital or orbital infections as additional symptoms of PVL + SA colonisation in children.

Methods

We conducted a retrospective cohort study of pediatric patients who were treated for PVL + SA skin and soft tissue infection in our in- and outpatient clinics in Berlin, Germany from January 2012 to January 2017. We identified cases with periorbital or orbital infections in the year prior to the first PVL + SA evidence. In these cases, we conducted follow-up interviews by phone to determine recurrence of symptoms after the completion of decolonisation procedures.

Results

Fifty pediatric patients (age range: one week to 17 years) were evaluated and treated for PVL + SA infections in the reported time period. 19 patients (38%) reported periorbital infection or conjunctivitis, with recurrent hordeola as the most frequent finding (n = 9; 18%). Reappearance of hordeola (n = 5) was associated with recurrence of skin and soft tissue infections and/or de novo detection of PVL + SA. No further hordeola or other eye infections occurred after successful decolonisation.

Conclusion

Our findings suggest a frequent involvement of periorbital skin in children with PVL + SA infections. Pediatric patients with recurrent periorbital infections might benefit from PVL + SA screening and consecutive decolonisation procedures.

Detection of methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples of patients with external ocular infection

BACKGROUND AND OBJECTIVES

Staphylococcus aureus is the main Gram-positive bacteria isolated from patients with ocular infections. Herein, we describe the pattern of antibiotic resistance, presence of resistance genes including ermA, ermB, ermC, msrA, mecA and the pvl cytotoxin gene in S. aureus isolates collected from patients with external ocular infection.

MATERIALS AND METHODS

In this study, 8 S. aureus isolates were collected from 81 patients that suffered from eye damage. Antibacterial susceptibility of isolates was determined using the Kirby-Bauer disk diffusion method. Resistance genes including ermA, ermB, ermC, msrA, mecA and the pvl virulence gene were detected by PCR method. Staphylococcal cassette chromosome mec (SCCmec) in MRSA isolates were detected by the multiplex-PCR method.

RESULTS

Three isolates were resistant to cefoxitin which is considered MRSA. The mecA gene was identified in MRSA isolates. SCCmec type IV and the pvl gene were detected in one of the MRSA isolates that was recovered from a diabetic patient.

CONCLUSION

The emergence of S. aureus isolates belonging to SCCmec type IV and pvl gene among patients with ocular infection is very serious; therefore, identify genetic characterization of MRSA isolates for empirical therapy and infection control is very important.

[A series of 20 cases of endogenous endophthalmitis]

BACKGROUND

The purpose of this case series was to evaluate both the visual and systemic prognosis of patients with endogenous endophthalmitis.

MATERIAL AND METHODS

We reported a series of 20 cases of endogenous endophthalmitis occurring between 2012 and 2015 at the university medical center in Toulouse.

RESULTS

The mean age was 67 (±43.3) years with a male predominance (n=11). The site of entry was found in 14 cases (87.5%). In 11 cases (69%), the causative agent was a bacterium; a fungal infection was found in five cases. Visual acuity after maximal medical and surgical treatment was limited to "no light perception" in 7 cases (35%), "hand motion" in 2 cases (10%), "finger counting" in 3 cases (15%) and 10/10 in 2 cases (10%). One case had no final data. The main site of entry was found to be associated endocarditis (n=7), central venous line or venipuncture (n=6). The main local complications were retinal detachment (n=6), cataract (n=5) and choroidal neovascularization secondary to scarring (n=2).

CONCLUSIONS

Endogenous endophthalmitis is associated with poor visual prognosis. It is also often associated with systemic complications that may be life-threatening.

Eye-related trauma and infection in dentistry

Despite numerous technological and medical developments achieved in recent years, a significant amount of occupational health problems still exist in modern dentistry. The risk of eye injury is mostly attributed to the use of high-speed hand pieces and ultrasonic devices. A dental clinic may be the source of eye-related infection and injury because of mechanical, chemical, microbiological and electromagnetic irritants. Accidents may cause facial injuries that involve eyes of the clinicians, patients as well as dental assistants. Eye injuries can vary from mild irritation to blindness. The use of eye protection tools, such as protective goggles and visors, reduces the risk of eye damage or complete loss of vision while working with dangerous and floating materials. Therefore, all precautions should be taken, even when performing common procedures for which the risk expectancy is relatively low. Clinicians should be aware that they are also responsible for providing adequate protection for their assistants and patients, as well as themselves.

[Endogenous bacterial and fungal endophthalmitis at Nice University Medical Center: A 15-year case review]

PURPOSE

To evaluate epidemiology, diagnostic and therapeutic management strategies and visual outcomes of cases of bacterial and fungal endogenous endophthalmitis managed in the Nice University Medical Center between January 2000 and June 2015.

METHODS

Three hundred twenty-three charts of patients with endophthalmitis treated at the Nice University Medical Center over this period were retrospectively reviewed to select the ones with endogenous endophthalmitis. Demographic characteristics, medical history, clinical presentation, diagnostic and therapeutic management, microbiology, and final outcomes were analyzed.

RESULTS

Twenty-two eyes of 20 patients were selected, constituting 6.20% of all cases of endophthalmitis. The mean age was 69years, and 75% of patients were male. The most common risk factors were diabetes, malignancies and cardiac diseases. Bacterial isolates were found in 16 cases (80%), fungal isolates in 3 (15%) and co-infection in 1 case. Gram-positive organisms accounted for 70.6% of cases (mostly Staphylococcus aureus [25%], Streptococcus agalactiae [25%] and Streptococcus pneumoniae [16.7%]). Candida albicans was the most common fungal organism. There was one bacterial and fungal co-infection. Two patients died, 4 eyes were enucleated or eviscerated (20%), and 4 patients (20%) attained a final visual acuity of 1/10 or better.

CONCLUSION

Endogenous endophthalmitis is a rare and serious condition with a poor prognosis. Gram-positive microorganisms, mostly S. aureus, were the main causative pathogens found.

Burden of acute infections (except respiratory and diarrheal) and its risk factors among under-five children in India: A systematic review and meta-analysis

CONTEXT

Acute infections of eyes, ears, skin, and others are a common cause of morbidity in under-five children. The overall burden of other infections and their risk factors is not known.

EVIDENCE ACQUISITION

Available literature was searched comprehensively using PubMed for acute infections (except acute respiratory and diarrheal diseases) using the relevant medical subject heading terms. Extracted articles were independently reviewed against inclusion/exclusion criteria and rated for quality. 10 articles were abstracted and reviewed to identify the reported prevalence and risk factors for acute infections among children.

RESULTS

The pooled prevalence of infections (not including acute respiratory and diarrhea) between 2002 and 2013 was 18.42 (95% confidence interval: 9.30-30.62), with reported range of 3.7-50.8%. The significantly positively associated factors reported in single studies were young age of the child, malnutrition, poor breastfeeding, low socio-economic status, animal rearing near household and mothers' illiteracy for independent morbidities.

CONCLUSION

The evidence on risk factors including breastfeeding, vaccination, age, and sex that predispose under-five Indian children to different infections is inconclusive. There is a need to conduct more studies on acute infections other than acute respiratory and diarrhea, to establish their determinants in Indian children.

Balancing antimicrobial efficacy and toxicity of currently available topical ophthalmic preservatives

Medical treatment of ophthalmic diseases relies primarily on the use of multidose drugs. Short term use is highly effective usually with little local toxicity. However, chronic use of these preparations not only increases the likelihood of microbial contamination and secondary ocular infection, but also of toxicity from the drug formulation itself. Increasing awareness of the toxicity of ophthalmic preservatives has led to an increasing variety of preservative schemes ranging from "self-preservation" to ionic buffer systems. Beyond outdated testing methods, the anti-microbial efficacy of most of these systems is poorly defined, potentially placing these preparations at an unknown risk of contamination by unmonitored, untested organisms. No uniformity in toxicity testing exists which further complicates the clinician's judgment of the risk-benefit of using a particular drug formulation. In this manuscript we examine in detail each of the current employed ophthalmic preservative regimens with respect to their known antimicrobial activity and potential toxicity, where known. We also survey the most popular ophthalmic preparations, detailing their preservation schemes as well as concentrations to help the clinician in choosing an appropriate formulation for the treatment of various ophthalmic diseases.