Keratitis due to a coelomycetous fungus: case reports and review of the literature.

PURPOSE: To describe a series of 7 patients with ulcerative keratitis caused by species of Colletotrichum, which are coelomycetous fungal pathogens. METHODS: The patients presented with keratitis of varying degrees of severity. Multiple scrapes from the corneal lesions of 6 of the 7 patients were used for microbiological investigations by a standard protocol. In the seventh patient, scraping was not performed due to the presence of deep infiltration and a descemetocele at presentation. All 7 patients were hospitalized and treatment was initiated with topical applications of natamycin (5%) and ciprofloxacin (0.3%) every hour and cyclopentolate (1%) drops 3 times daily. An emergency therapeutic penetrating keratoplasty was performed after 48 hours in the patient who had presented with a descemetocele and for another patient whose keratitis did not respond to 10 days of medical therapy. RESULTS: The corneal samples of all 7 patients yielded significant growth of filamentous fungi in culture. On the basis of macroscopic and microscopic characteristics, the fungal isolates were identified as Colletotrichum spp. Corneal lesions completely resolved with medical therapy alone in 5 patients. In the 2 patients who had undergone therapeutic penetrating keratoplasty, the infection was eradicated and the corneal graft remained clear even after several months of follow-up. CONCLUSION: Colletotrichum spp may be more frequent causes of keratitis than previously thought. Keratitis due to Colletotrichum spp frequently responds to medical therapy alone, although surgery may be indicated in a small proportion of patients.

Comparison of in vitro characteristics of and experimental lesions produced by a clinical and an environmental isolate of Aspergillus flavus.

In the present study, two strains of Aspergillus flavus (one from a human corneal ulcer and one from the environment) were found to be strikingly similar in vitro in terms of thermotolerance, inability to grow in an anaerobic environment and in secreting proteinases; however, one obvious difference was that the clinical isolate produced 120 ppb of aflatoxin B1 in glucose salt medium while the environmental isolate did not produce this toxic metabolite. Alterations in the activities of acid phosphatase (ACP), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and glutathione-S-transferase were observed in the liver, kidney and serum in an experimental rat model, irrespective of whether the animal had been challenged with the clinical isolate or the environmental isolate of A. flavus. In rats that had been challenged with the clinical isolate, a significant decrease in the activity of kidney ALP was noted, whereas in rats that had been challenged with the environmental isolate, the reverse was observed. While these differential alterations may have occurred due to differences in the toxin-producing ability of the two isolates, further investigation is warranted to clarify whether other phenotypic, or genotypic, differences are also involved.

Microbiological profile of bacterial pathogens from diabetic foot infections in tertiary care hospitals, Salem.

BACKGROUND: Worldwide, diabetic foot infections are one of the most serious complications resulting in long term hospitalization among the diabetic patients. AIM: The aim of this study was to determine the microbial profile and the antibiogram pattern of the patients with diabetic foot infections. METHODS: Pus samples were taken from 50 patients presenting with diabetic foot infections over a period of 10 months. The samples were processed by standard microbiological methods. RESULTS: A total of 51 bacterial isolates were obtained from 50 patients with diabetic foot infections. The age group of these patients ranged from 30 to 80 years and the maximum number of patients were in the age group of 51-60 years. Gram negative (51%) were more prevalent than Gram positive (49%) organisms in this study. The commonest isolate was Staphylococcus aureus (41%) followed by Pseudomonas aeruginosa (35%), Enterococcus spp., (4%), Escherichia coli, (4%), Salmonella spp., (4%), Bacillus spp., (4%), Micrococcus spp., (2%), Listeria spp., (2%), Shigella spp., (2%) and Proteus spp., (2%). The antibiotic sensitivity pattern showed Meropenem, Piperacillin, Cefoperazone/Sulbactam, Piperacillin/Tazobactam and Amikacin as the most effective antimicrobial agents for the gram positive and Gram negative bacterial species. In this study, 8(44%) isolates of Gram negative bacilli were ESBL producers and 4 (19%) isolates were MRSA strains. CONCLUSION: The results of the study indicate that effective planning of therapy is very essential for the prevention of drug resistant organisms.