ABSTRACT
Background & objectives: Ocular infection with Chlamydia trachomatis is a major public health problem in densely populated countries like India. The true prevalence of such infections is uncertain due to insufficient data available from India. The aim of this study was to do a retrospective analysis of C. trachomatis eye infections in patients attending the outpatient department of Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, over a period of 12 years. Methods: From 1997 to 2008, the Chlamydia laboratory received conjunctival swabs from 1281 consecutive patients for C. trachomatis detection after thorough clinical examination. Specimens were subjected to direct fluorescent antigen detection assay using monoclonal antibody based commercial kit to detect the presence of C. trachomatis antigen. Results: Antigen positivity varied between 22-28 per cent. Children below 11 yr and people above the age of 60 yr showed comparatively higher antigen positivity (25.7 and 27.8%, respectively). As compared to males significantly (P<0.05) higher number of females in the age group of 31-60 yr were positive for C. trachomatis antigen. Patients with the clinical diagnosis of follicular/allergic conjunctivitis and trachoma showed higher rate of antigen positivity. Interpretation & conclusions: Northern India having dry and arid climatic conditions in most parts of the year was considered in the past as one of the trachoma hyper-endemic foci. The study indicated that laboratory proven C. trachomatis eye infection still persisted in this part of the country throughout the study period of 12 years.
ABSTRACT
Background & objectives: Though not frequently but there are reports showing phacoemulsifiers as a potent source of infection in post-operative cases of endophthalmitis. This study was carried out to find antibiogram and genetic relatedness between Pseudomonas aeruginosa isolates from a post-cataract surgery endophthalmitis outbreak (3 patients) and internal tubings of 5 phacoemulsifiers. Methods: In vitro antimicrobial sensitivity patterns of the 8 bacterial isolates were observed. Genetic analysis of the bacterial isolates was done using random amplification of polymorphic DNA (RAPD) assay and PCR ribotyping. The resulting DNA band patterns were examined visually and by computer assisted analysis using unweighted pair group method. Results: The three P. aeruginosa patient isolates were found to be different from the five phacoemulsifier isolates in sensitivity towards 3 antibiotics and by genetic analysis (33 and 44% homology by RAPD assay and PCR ribotyping). Two of the patient isolates shared 100 per cent genetic homology by RAPD assay and another pair shared 100 per cent homology by PCR ribotyping. The five isolates from phacoemulsifiers did not share significant genetic homology. There was significant genetic variation between bacterial isolates from patients and phaco emulsifiers. Interpretation & conclusion: Though the three P. aeruginosa isolates obtained from the patients were phenotypically similar and genetically close, they differed from the phaco-machine isolates both genetically, and in their antibiogram profile. However, the five phacoemulsifier isolates were genetically diverse though they shared the same antibiogram profile. Therefore the Ringer’s lactate from phacomachines could not be conclusively proven to be the source of infection.