Bacterial keratitis is a devastating condition that can rapidly progress to serious complications if not treated promptly. Certain causative microorganisms such as Staphylococcus aureus and Pseudomonas aeruginosa are notorious for their resistance to antibiotics. Resistant bacterial keratitis results in poorer outcomes such as scarring and the need for surgical intervention. Thorough understanding of the causative pathogen and its virulence factors is vital for the discovery of novel treatments to avoid further antibiotic resistance. While much has been previously reported on P. aeruginosa, S. aureus has been less extensively studied. This review aims to give a brief overview of S. aureus epidemiology, pathophysiology and clinical characteristics as well as summarise the current evidence for potential novel therapies.

Purpose: To investigate the use of a corneal impression membrane (CIM) for the detection of Herpes Simplex Virus type 1 (HSV-1) in suspected Herpes Simplex Keratitis (HSK). Materials and Methods: In the laboratory study, swabs and CIMs made from polytetrafluoroethylene were spiked with different concentrations of HSV-1. DNA was extracted and real time PCR undertaken using 2 sets of primers. In the clinical study consecutive patients presenting with suspected HSK were included. For each patient, samples were collected from corneal lesions with a swab and a CIM in random order. Clinical details were collected using a standardised clinical form and patients were categorized into probable, presumed and possible HSK. Results: There was no difference in the performance of both primer sets for all HSV-1 dilutions (p=0.83) or between a CIM and a swab (p=0.18). 110 patients were included. Seventy-three patients (66.4%) had probable, 20 patients (18.2%) presumed, and 17 patients (15.5%) possible HSV-1 keratitis. The HSV-1 detection rate was significantly higher using a CIM (40/110, 36.4%) than a swab (28/110, 25.5%) (p=0.004). In the probable HSV keratitis group, the detection rate using a CIM was 43.8% compared to 27.4% for a swab (p=0.004). The Cp values obtained for the conjunctival swabs were higher than those obtained for the CIMs (p<0.001). Conclusions: In suspected HSK, a CIM is a useful alternative to a swab and more likely to detect the presence of HSV-1.