Pythium keratitis in South India: Incidence, clinical profile, management, and treatment recommendation

Purpose: To study the demographic profile, clinical features, treatment outcome, and ocular morbidity of microbiologically proven Pythium keratitis in South India. Methods: A retrospective analysis of clinical records of microbiologically proven Pythium keratitis at a tertiary eye care referral center in South India from January 2016 to November 2017 was performed. Demographic details, predisposing risk factors, microbiological investigations, clinical course, and visual outcome were analyzed. Results: Seventy-one patients with microbiologically proven Pythium keratitis were identified. The mean age was 44(±18.2) years with an increase in male preponderance and 50% were farmers. Duration of delay at time of presentation to the hospital was a mean of 14(±7.2) days. The visual acuity at baseline ranged from 6/6 to no light perception (median 2.1 logMAR). A combination of 5% natamycin and 1% voriconazole was given to 42% patients, and natamycin alone was given to 39.4% patients. 1% itraconazole eye drops alone was initiated in 7 (10%) patients and 3 among this group responded. Therapeutic keratoplasty (TPK) was performed in 48 (67.6%) patients. None of the primary grafts remained clear after a period of 1 month. Twenty-six eyes (54.2%) had graft reinfection and all these eyes either developed anterior staphyloma (4) or were eviscerated (3) and 13 eyes became phthisical. The remaining 22 patients who had TPK resulted in failed graft. Among these, re-grafts were performed in 6 patients, of which 5 were doing well at the last follow-up. Conclusion: We report a large series of patients with Pythium keratitis. Promoting early and differential diagnosis, awareness of clinicians and specific treatment options are needed for this devastating corneal disease.

Fungal keratitis caused by Podospora austroamericana: A first case report

We report a case of keratitis caused by a rare fungus Podospora austroamericana. Clinical and microbiological evaluation of the corneal ulcer was done and the treatment outcome was studied. The fungus was grown from the corneal scraping, and it was identified as P. austroamericana based on DNA sequence and analysis of the internal transcribed spacer region. The patient was treated with topical azithromycin, natamycin and voriconazole. Despite maximum medical therapy, the ulcer progressed very rapidly and the patient developed panophthalmitis and evisceration of the eye had to be done. This is the first reported case of keratitis caused by P. Austroamericana.

Phyto-assisted synthesis and characterization of silver nanoparticles from amaranthus dubius.

The aqueous extract of Amaranthus dubius was used for the green synthesis of silver nanoparticles from silver nitrate solution under various conditions. The silver nanoparticles were characterized by spectrophotometric, physical and theoretical methods. The size of silver nanoparticles ranged from 10-70nm. The present approach of biosynthesis of silver nanoparticles using aqueous extract of A.dubius appears to be cost efficient, eco-friendly and an easy alternative to conventional chemical method of synthesis.

Detection of Cryptosporidium parvum in HIV-infected patients in Malaysia using a molecular approach.

This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.

Susceptibility trends of pseudomonas species from corneal ulcers.

PURPOSE: To assess the changing trends in the antibiotic susceptibility of Pseudomonas spp . isolated from bacterial keratitis over a nine year period with special emphasis on fluoroquinolone susceptibilities. METHODS: All corneal scraping cultures positive for Pseudomonas spp. (n=585) isolated from patients with bacterial keratitis at the Aravind Eye Hospital, Madurai from 1995-2003 were evaluated. Cultures were performed in liquid and solid media and susceptibility testing was done against amikacin, gentamicin, tobramycin, ciprofloxacin and ofloxacin by Kirby-Bauer disc diffusion method. RESULTS: The susceptibility of Pseudomonas spp. was over 90% from 1995-1998 to ciprofloxacin which decreased to 83% from 1999-2003. The total number of isolates resistant to ciprofloxacin was 51 (9.4%). No statistically significant increase in the number of isolates resistant to ciprofloxacin was noted. Ofloxacin showed 54% susceptibility from 1995-1998 but increased to 64% from 1999-2003. Analysis of in vitro activity of amikacin reveals that there was 43% sensitivity from 1995-1998 but later it increased to 76% from 1999-2003. In case of gentamicin, the sensitivity decreased marginally from 80% to 70% through the years. Tobramycin showed 45% sensitivity from 1995-1998 but increased to 75% from 1999-2003. CONCLUSIONS: The fluoroquinolones remain a good choice in the treatment of ocular infections, with high susceptibility of Pseudomonas spp. Among the aminoglycosides, gentamicin was found to be highly effective against Pseudomonas corneal ulcers when compared to amikacin and tobramycin. The results show a need for continuous monitoring of bacterial resistance trends.

Ocular infections due to non-tuberculous mycobacteria.

PURPOSE: To investigate the types and causes of non-tuberculous ocular infections and study their response to topical antibiotic therapy. METHOD: A single center, retrospective review of 18 patients with non-tuberculous mycobacterial ocular infections, seen over a 3 year period was done. Laboratory diagnosis was established by growth on blood agar, LJ medium and Ziehl-Nielsen acid fast stain. RESULTS: Out of 18 patients, six had post corneal graft infection, six had corneal ulcers, three had endogenous endophthalmitis, one had post operative endophthalmitis and two cases were of post surgical wound infection. History of trauma was reported in two cases and surgery in nine cases. M.chelonae was grown in blood agar for all patients. For corneal infections fortified genatmicin and fortified amikacin topical eye drops were given while the cases of endophthalmitis received intravitreal amikacin. Response to treatment was poor in 16 cases (88.9%). Only two cases of corneal ulcer improved after prolonged treatment. There was a misdiagnosis of Corynebacterium spp. on Gram stain in the initial cases. Majority of the isolates were sensitive to gentamicin (72.2%) followed by amikacin (44.4%). CONCLUSIONS: Early clinical recognition and prompt laboratory diagnosis together with aggressive topical antibiotic therapy may shorten morbidity and improve the clinical outcome of non-tuberculous mycobacterial ocular infection.

Optimisation of immunoaffinity purification of Wuchereria bancrofti specific antibodies from human sera.

Immunoaffinity column using Setaria digitata antigens coupled to cyanogen bromide activated Sepharose 4B beads were developed to purify antibodies from sera of filarial patients. Chaotropic (KSCN) ion elution was more efficient for purifying specific antibodies from the column in comparison to ]c elution. Dot blot analysis indicated that purified antibodies showed a high degree of reactivity with cattle filarial antigen and recombinant filarial protein but not with bacterial proteins of E. coli suggesting that the antibodies are specific.

Do silver stained structures in vaginal parabasal cells identify a different population of cells in buffaloes?

A modified single step silver colloidal staining method for interpretation of routine vaginal smears of buffaloes which aids in analysing every component under light microscope with minimum efforts has been suggested, and it can be adopted in all clinical laboratories. A novel population of parabasal cells has been described which was distinct in morphology and nuclear distribution of silver stained structures (SSS). These SSS has been designated as the 'parabasal dots'. The significance of these cells needs further investigation and confirmation.