Rose Bengal-Mediated Photodynamic Antimicrobial Treatment of Acanthamoeba Keratitis.

Purpose: To evaluate the in vivo efficacy of rose bengal (RB)-mediated photodynamic antimicrobial therapy (PDAT) for treatment of Acanthamoeba castellanii keratitis (AK). Materials and Methods: An animal (rabbit) AK model was successfully achieved via intrastromal inoculation of a suspension of A. castellanii cells and trophozoites. Prior to RB-PDAT (pre-treatment, day-5), the severity of the induced corneal infection was graded numerically for epithelial defects, stromal edema, neovascularity, and stromal opacity/infiltration. The right eyes of rabbits (n = 18) were divided equally into three groups (n = 6/group): control (no treatment); 0.1% RB+518 nm irradiation (5.4 J/cm2); and 0.2% RB+518 nm irradiation (5.4 J/cm2). On post-treatment day-5, animals were euthanized, after which corneal buttons were excised and submitted for real-time polymerase chain reaction (RT-PCR) analysis. Results: Post-treatment clinical scores of the 0.1 and 0.2% RB groups indicated significant improvement compared to control group scores (pre-treatment clinical scores; 5.17 ± 0.98, 7.50 ± 0.62, and 6.17 ± 0.70 and post-treatment clinical scores; 4.50 ± 0.56, (p = .043), 3.50 ± 0.99 (p = .039), 6.83 ± 1.66 (p = .34), respectively). RT-PCR analysis revealed that the mean cycle threshold (Ct) values were significantly higher in treated-group corneas compared to control-group corneas, with no significant differences between treated-groups (Mean Ct values; 34.33, 34.5, and 29.67 for 0.1 and 0.2% RB, and control groups). There was a statistically significant negative correlation between post-treatment clinical scores and Ct values (r = -0.474, p-value 0.047). Conclusions: Our results demonstrate that RB-PDAT is effective in decreasing the parasitic load and clinical severity of AK.

[Microsporidium spp. infection in an immunocompromised child diagnosed by polymerase chain reaction]. / Immün sistemi baskilanmis bir çocukta Microsporidium spp. Enfeksiyonunun polimeraz zincir reaksiyonu ile tanimlanmasi

Microsporidium spp. may lead to a variety of clinical pictures like sinusitis, keratoconjunctivitis, hepatitis, myositis, peritonitis, nephritis, encephalitis and pneumonia in case of immune deficiencies. In this report, a case of diarrhea due to Microsporidium spp. has been presented. A four years old male patient who was followed with the diagnosis of myotonic dystrophia, was admitted to the hospital with the complaints of respiratory distress and fever. Due to the history of recurrent infections, further investigations was carried out to clarify the immunological status of the patient, and the total IgA and IgM levels were found as 14 mg/dl and 30 mg/dl, respectively (normal values were; 18-160 and 45-200 mg/dl, respectively). Following bronchoscopy done to enlighten respiratory distress, the patient developed high fever and watery diarrhea. Since bacteriological cultures of the stool yielded Shigella spp., antimicrobial therapy with ciprofloxacin was initiated. Parasitological examination of the stool done by Weber's modified trichrome dye, yielded Microsporidium spp. microscopically and albendazole was added to the treatment. Presence of Microsporidium spp. was confirmed by polymerase chain reaction with the use of C1 and C2 primers (Metabion, Germany) targeted to Microsporidium spp. and besides a 270 bp band specific for Encephalitozoon intestinalis was also obtained. This case emphasized that in case of diarrhea the stool samples of the immunocompromised patients should be evaluated in terms of Microsporidium spp. in addition to the routine parasitologic examinations.