A Prospective Microbiological Study on Suppurative Corneal Ulcer at a Tertiary Teaching Hospital in Bhavnagar , Gujarat , India

It is important to study the epidemiological features and predisposing factors of suppurative corneal ulcers. Subsequently, it is also important to find out its causative microbial agents and their antimicrobial sensitivity-resistance patterns in a particular climate and culture of a particular region of a country. This prospective study was carried out on patients suffering from suppurative corneal ulcer to know the particular bacterial and fungal (not viruses) prevalence as a causative microbial agent for these suppurative corneal ulcers at a particular region of Gujarat and the distribution this disease among the people of different age, sex and occupational group in this region. It is a prospective study on 112 patients suffering from suppurative corneal ulcers. All the patients are examined thoroughly by ophthalmologist on slitlamp biomicroscope. After proper clinical examination of every patient and before any treatment was initiated, the samples were taken from all the clinically suspected suppurative corneal ulcers, using standard technique, by swabs and scrapings under strict aseptic condition. The scraping procedure was performed using Bard Parker blade, under magnification of slitlamp microscope or operating microscope, after instillation of 2% lignocaine without preservative. The specimen material was scraped from the edge and the base of the ulcers. The swabs were directly inoculated on to the surface of solid medias, such as blood, Mac Conkey and Sabourad,s dextrose agar media. The scraping materials were used for preparation of smear for Gram stain and 10% KOH wet mount. The bacterial growths were identified by colony morphology, smear preparation from colony, followed by Gram stain and microscopy, followed by standard biochemical tests. The fungal growths were also identified by colony morphology, Gram stain for yeast and yeast like group of fungi and LPCB wet mount preparation for mycelial group of fungi. For diagnosis of fungi the help of biochemical and immunological tests was also taken. Out of total 112 specimens of suppurative corneal ulcers, only 76 specimens were found to be culture positive in which bacteria were isolated more frequently than fungi. The coagulase negative staphylococcus (CONS) were the most frequently isolated bacteria and the genus Aspergilous were the most frequently isolated fungi. All the bacterial isolates, not the fungi, were passed through antibiotic sensitivity testing (ABST) by KirbyBauer disk diffusion method. The incidences of suppurative corneal ulcers were higher in males than females. Patients between 40 to 50 Years of age group were most affected. Ocular trauma, predisposing to suppurative corneal ulcer was identified as the major risk factor, compared to other predisposing factors. The epidemiology, the predisposing factors, the causative microbial agents and their antimicrobial pattern of suppurative corneal ulcer vary geographically. The CONS and the Aspergillous spp. were the most frequent isolates from suppurative corneal ulcer in our institution. The incidences were higher among rural population, especially among labourers who were constantly exposed to different types of vegetative and nonvegetative traumatic matters.