Endophthalmitis: Microbiology and Organism Identification Using Current and Emerging Techniques.

Endophthalmitis is an ophthalmological emergency requiring timely and appropriate diagnosis and treatment. Microbiological methods of microscopy (Gram's staining) and culture are the current gold standard for organism identification. However, a significant proportion of endophthalmitis remains culture-negative-perhaps the inflammation is non-infectious in origin, results from a novel organism are unidentifiable or because the causative organism is non-culturable often due to pre-treatment with antibiotics. This review outlines the microbiological profile of endophthalmitis, current clinically used methods for organism identification, and the newer molecular techniques of polymerase chain reaction (PCR) and next-generation sequencing (NGS) technology as diagnostic tools for endophthalmitis. They offer the potential to improve organism identification rates and clinical outcomes in infectious diseases, representing an exciting future direction for organism identification in endophthalmitis. Based on the largest ophthalmic hospital in Australia, we highlight the key practical challenges faced by Australian diagnostic laboratories for their use in a clinical setting.

Where Have All the Diagnostic Morphological Parasitologists Gone?

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices. Recently, the introduction of multiplex panels for human gastrointestinal infections has enhanced the identification of common intestinal protozoa in feces along with bacterial and viral pathogens. Despite the benefits provided by novel diagnostics, increased reliance on nonmicroscopy-based methods has contributed to the progressive, widespread loss of morphology expertise for parasite identification. Loss of microscopy and morphology skills has the potential to negatively impact patient care, public health, and epidemiology. Molecular- and antigen-based diagnostics are not available for all parasites and may not be suitable for all specimen types and clinical settings. Furthermore, inadequate morphology experience may lead to missed and inaccurate diagnoses and erroneous descriptions of new human parasitic diseases. This commentary highlights the need to maintain expert microscopy and morphological parasitology diagnostic skills within the medical and scientific community. We proposed that light microscopy remains an important part of training and practice in the diagnosis of parasitic diseases and that efforts should be made to train the next generation of morphological parasitologists before the requisite knowledge, skills, and capacity for this complex and important mode of diagnosis are lost. In summary, the widespread, progressive loss of morphology expertise for parasite identification negatively impacts patient care, public health, and epidemiology.

A Case of Trauma-Induced Falciformispora lignatilis Eumycetoma in a Renal Transplant Recipient.

Mycetoma is a chronic, granulomatous, subcutaneous infection caused by several species of fungi and soil-inhabiting bacteria, and is divided into eumycetoma and actinomycetoma, respectively. Endemicity is described with worldwide distribution within the "mycetoma belt"; however, the global burden is ill-defined. Mycetoma is rare in Australia, with only a few published case reports. Over time, the breadth of eumycetoma pathogens has expanded with local epidemiology accounting for variations in regional prevalence. Direct inoculation of pathogens typically heralds the triad of subcutaneous mass, sinus formation and discharging grains. We describe a case of eumycetoma in a 48-year-old male Filipino renal transplant recipient who presented with a painless slow-growing elbow lesion. Ultrasonography revealed two ovoid masses and surgical excision ensued. Histopathology revealed necrotising granulomata with numerous chestnut-brown thick-walled cells, septate hyphae, and occasional grains. On suspicion of localised chromoblastomycosis, the isolate was sent to a reference laboratory which identified the fungus as Falciformispora lignatilis, an organism not hitherto associated with human infection. Amongst the solid organ transplant cohort, similar atypical presentations have been described. Clinicians need to consider eumycetoma where an epidemiological link with the tropics exists, especially in atypical presentations in transplant recipients, including absent preceding trauma.

Ocular Filariasis in Human Caused by Breinlia (Johnstonema) annulipapillata Nematode, Australia.

We report a human case of ocular filariasis, caused by a species of Breinlia nematode, from Queensland, Australia. Morphological and molecular evidence indicated that the nematode Breinlia (Johnstonema) annulipapillata, or a closely related taxon, likely transmitted from a macropodid marsupial host was involved, which might represent an accidental finding or an emerging zoonosis.

Gram-negative endophthalmitis: A prospective study examining the microbiology, clinical associations and visual outcomes following infection.

IMPORTANCE: This is the largest Gram-negative endophthalmitis specific series and provides important evidence to guide management. BACKGROUND: Endophthalmitis is a sight-threatening emergency. Gram-negative infections are associated with poorer visual outcomes; however, there is limited literature pertaining to this uncommon condition. DESIGN: Prospective case series. PARTICIPANTS: All patients presenting with endophthalmitis to a tertiary institution over a 20-year period. METHODS: Data were collected prospectively and entered into a registry. Patients with microbiological evidence of Gram-negative infection were included in the analysis. MAIN OUTCOMES MEASURES: Final visual acuity (VA), precipitating events, causative organisms, antibiotic sensitivity profiles and risk factors for poor visual outcomes were reported. RESULTS: One hundred Gram-negative organisms were isolated in 97 eyes. Final VA was worse than 6/60 in 65 (67.0%) eyes at follow-up and 29 (29.9%) eyes were eviscerated or enucleated. Microbial keratitis (26.8%, n = 26) and Pseudomonas aeruginosa (34.0%, n = 34) were the most common precipitating event and causative organism, respectively. Eight (8.0%) isolates were third-generation cephalosporin resistant; of which, 7 (88.0%) were sensitive to ciprofloxacin. Preceding microbial keratitis (OR = 13.16, P = .015) or P. aeruginosa infections (OR = 3.40, P = .045) were strongly associated with poorer visual outcomes (worse than 6/60). CONCLUSIONS AND RELEVANCE: Visual outcomes following Gram-negative endophthalmitis are extremely poor, with almost 30% of patients being eviscerated or enucleated. A majority of ceftazidime resistant organisms are sensitive to ciprofloxacin, providing evidence to support the empirical use of quinolones. Clinicians should be mindful that infections secondary to P. aeruginosa or microbial keratitis carry a particularly poor prognosis.

Australian consensus statements for the regulation, production and use of faecal microbiota transplantation in clinical practice.

OBJECTIVE: Faecal microbiota transplantation (FMT) has proved to be an extremely effective treatment for recurrent Clostridioides difficile infection, and there is interest in its potential application in other gastrointestinal and systemic diseases. However, the recent death and episode of septicaemia following FMT highlights the need for further appraisal and guidelines on donor evaluation, production standards, treatment facilities and acceptable clinical indications. DESIGN: For these consensus statements, a 24-member multidisciplinary working group voted online and then convened in-person, using a modified Delphi approach to formulate and refine a series of recommendations based on best evidence and expert opinion. Invitations to participate were directed to Australian experts, with an international delegate assisting the development. The following issues regarding the use of FMT in clinical practice were addressed: donor selection and screening, clinical indications, requirements of FMT centres and future directions. Evidence was rated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. RESULTS: Consensus was reached on 27 statements to provide guidance on best practice in FMT. These include: (1) minimum standards for donor screening with recommended clinical selection criteria, blood and stool testing; (2) accepted routes of administration; (3) clinical indications; (4) minimum standards for FMT production and requirements for treatment facilities acknowledging distinction between single-site centres (eg, hospital-based) and stool banks; and (5) recommendations on future research and product development. CONCLUSIONS: These FMT consensus statements provide comprehensive recommendations around the production and use of FMT in clinical practice with relevance to clinicians, researchers and policy makers.

E-Diagnosis in Medical Parasitology.

Over the past decade or two, the teaching of laboratory diagnostic parasitology has been neglected in Australasia, as parasitic infections are relatively uncommon. As a consequence, expertise in medical parasitology is dwindling. A team of international experts (including Professor John Goldsmid) has been formed to help in the diagnosis of human parasitic infections. The team includes experts from Australia, Europe, South Africa and the USA. Some senior members of the team are excellent morphologists, and we have both human and veterinary parasitologists who help with molecular diagnosis in difficult cases.

PCR-coupled sequencing achieves specific diagnosis of onchocerciasis in a challenging clinical case, to underpin effective treatment and clinical management.

This study demonstrates the utility of a PCR-based DNA sequencing approach to make a specific diagnosis of onchocerciasis in a returned traveller. Although a clinical diagnosis was not possible, the surgical excision of a suprascapular nodule from this patient, combined with an histological examination of this nodule and PCR-based sequencing of DNA from a nematode from this lesion solved the case. The analysis of DNA sequence data confirmed the presence of Onchocerca volvulus infection, supporting an effective treatment-clinical management strategy for the patient.

Seafood-borne parasitic diseases in Australia: are they rare or underdiagnosed?

Australia is a multicultural country surrounded by water where seafood is regularly consumed. Literature suggests that some popular edible fish sold in fish markets may be infected with parasites transmissible to humans (notably, anisakids and other helminths); however the number of reported human cases due to these parasites is low. In this article we critically review topical publications to understand whether the low number of human infection is due to lack of expertise in Australia to identify and diagnose accurately seafood-borne parasitic infections. The risk these parasites pose to humans may be underestimated due to: (i) errors or inability of diagnosing these infections, primarily due to less sensitive and specific serological tests and misidentifying parasites without a taxonomist in the diagnostic team; and (ii) medical practitioners not being aware of these parasites or not considering them in the differential diagnosis even in patients with history of regular raw or undercooked seafood consumption.

Unusual clinical presentations of new-onset herpetic eye disease after ocular surgery.

PURPOSE: To report five cases of new-onset herpetic eye disease with unusual presentation after ocular surgery. METHODS: Herpetic eye disease was suspected in five cases, three after cataract surgery and two after lamellar corneal transplantation surgery. Of these, four cases presented within 2-6 weeks of surgery. The clinical presentation was in the form of an epithelial defect, suspected epithelial down growth, graft oedema with unexplained anterior chamber inflammation and graft-host interface infection. A swab for viral detection with real-time polymerase chain reaction was performed in all the described cases. RESULTS: Herpes simplex disease was detected in all cases. All cases responded to the antiherpetic medications. CONCLUSIONS: Our study shows that new-onset herpetic eye disease may occur after cataract surgery and lamellar corneal transplantation, and a high index of suspicion may be necessary for the diagnosis in such cases.

Scedosporium scleritis or keratitis or both: case series.

PURPOSE: To report case series of infectious scleritis or keratitis or both caused by Scedosporium fungal species. METHODS: Medical records of patients presenting with infectious scleritis or keratitis or both caused by Scedosporium were retrospectively reviewed at a tertiary care hospital. Nine culture-proven cases of Scedosporium corneal and scleral infection that were treated medically or surgically or both were enrolled for the study. The main parameters evaluated were the predisposing factors, clinical presentation, and the success of various treatment modalities. RESULTS: The most common mode of presentation was scleritis (six cases, 67%), followed by sclerokeratitis (two cases, 22%) and keratitis (one cases, 11%). The risk factors included a previous pterygium excision with or without beta-radiation (six cases, 67%) and trauma (two cases, 22%). One patient had no identifiable risk factor. Mean duration between the time of pterygium excision and onset of infectious scleritis or keratitis or both was 7.6 +/- 3.3 years (range, 5-12 years). Voriconazole was the most commonly used antifungal medication in the form of drops (five cases, 56%) or tablets (five cases, 56%). Medical therapy alone could successfully resolve infection in six cases. Penetrating keratoplasty was performed in one eye, and two eyes were enucleated. CONCLUSIONS: Corneal and scleral infection caused by Scedosporium may occur many years after pterygium surgery. Although newer antifungal agents like voriconazole are effective in management of such cases, severe infections may result in the loss of eye.

Searching for Salmonella.

BACKGROUND: Salmonella species are responsible for two distinct syndromes. Nontyphoidal Salmonella are common causes of food borne gastroenteritis. Typhoidal Salmonella cause enteric fever; an important differential diagnosis in any traveller returning from a tropical country with fever. OBJECTIVE: This article describes the spectrum of disease that occurs with Salmonellosis infections and particular subgroups of patients who are more susceptible to severe disease. An appreciation of this will allow the clinician to manage these infections appropriately. DISCUSSION: Nontyphoidal Salmonellosis infections causing gastroenteritis are common in our community. Infection is caused by ingesting contaminated food or water, or occasionally by contact with an infected person. Most cases are self limiting and the focus of management is effective rehydration. Antibiotic therapy is seldom warranted but important exceptions exist including neonates, the immunocompromised, and in particular circumstances, the elderly. Enteric fever always warrants antibiotic treatment. Notification to the appropriate health authority assists with investigating possible outbreaks.

Association between cultures of contact lens and corneal scraping in contact lens related microbial keratitis.

OBJECTIVE: To study the association between cultures of contact lens and corneal scraping in contact lens-related microbial keratitis. METHODS: A retrospective analysis of the culture results of corneal scrapings and contact lenses of patients with contact lens-related microbial keratitis who were initially seen at Royal Victorian Eye and Ear Hospital, Melbourne, Australia, between January 1, 2001, and December 31, 2004, was conducted. RESULTS: Fifty eye specimens of 49 patients were included in the study. Corneal scrapings and contact lenses were culture positive in 17 eyes (34%) and in 35 eyes (70%), respectively. In 13 eyes, corneal scrapings and contact lenses yielded identical organisms. Serratia marcescens was the most common organism isolated from the corneal scrapings and from the contact lenses. CONCLUSION: Contact lens culture may sometimes give a clue to the organism involved in cases of microbial keratitis in which the corneal scraping is culture negative and may help in choosing the appropriate antimicrobial therapy.