https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/57 Tue, 02 Aug 2016 11:30:40 +0000 Conjunctival flora refers to population of microorganisms that dwell within the eyes of healthy individuals and is important in maintaining a healthy ocular surface and normal conjunctival function. Conjunctival flora may be altered by a variety of factors that include age, immunosuppression and geography. Immune function is compromised in diabetes mellitus. The aim of the present study was to see the pattern of conjunctival bacterial flora in diabetic and non-diabetic patients. This cross sectional study was carried out in BSMMU during the period of January 2011 to December 2011. Total 500 conjunctival swabs were collected from both eyes of 50 diabetic patients attending OPD of Endocrinology Department of BSMMU and 200 non-diabetic individuals. Significant number of culture was positive in diabetic patients (64.0%) compared to that of non-diabetic individuals (38.0%). Staphylococcus epidermidis was predominant  in both study groups (diabetic vs non-diabetic: 41.3% vs 65.26%). Staphylococcus aureus (15.22%), Escherichia coli (6.52%) and Enterobacter (8.33%) were isolated in diabetic patients. Rate of positive culture in both and single eyes were higher in diabetic (28%, 36.0%) than that of non-diabetic individuals (9.5%, 28.5%). Introduction In a healthy person, surface tissues such as skin and mucous membranes are constantly in contact with environmental organisms and becomes colonized by various micro-organisms which are referred to as normal flora.3 Bacteria and fungi are considered as normal flora of conjunctiva whereas viruses and parasites are not considered as the members of the normal flora.4 Normal conjunctival flora remains relatively consistent among human populations. However, it may be altered by a variety of factors including age, immunosuppression, ocular inflammation, dry eye, use of contact lens use, antimicrobials, surgery, external exposure, climate and geography. Some members of the conjunctival flora play a pathogenic role in diabetes mellitus when immune function is compromised, which may lead to serious infection.6 As such, the present study was designed to see the pattern of conjunctival bacterial flora in healthy individuals and diabetic patients. Materials and Methods   Total 250 patients attending Eye OPD of BSMMU with complaints other than eye infections, mostly refractive error, were enrolled in the study. On the basis of history and glycemic status 50 patients were included in the diabetic group and another 200 were non-diabetics. Slit lamp examination was performed on each patient to find out any evidence of infection or inflammation. Sample collection   Smear was prepared with one swab from each sample and Gram staining was performed to demonstrate pus cells to exclude infection. Second swab was inoculated onto blood agar, chocolate agar, MacConkey agar, blood tellurite agar and Haemophilus selective agar media and were incubated at 37ºC aerobically for 48 hours. Chocolate agar and Haemophilus selective agar plates were incubated in candle extinction jar. After 48 hours, all the organisms were identified by standard microbiological procedures namely colony morphology, Gram staining, pigment production and relevant biochemical tests (catalase, coagulase, novobiosin sensitivity, oxidase, MIU, mannitol fermentation, bile solubility, bile esculin test, rapid carbohydrate utilization test, growth factor requirement test, Haemophilus satellitism and butyrate esterase test).9,10 All data were collected in a predesigned data sheet and checked, edited and analyzed using SPSS (Statistical Package of Social Science) software. The data obtained from healthy individuals and diabetic patients were compared by Chi-square (χ2) test. Results     Among the culture positive samples, different bacterial species were isolated from conjunctival swabs of diabetic and non-diabetic patients. S. epidermidis was the most commonly isolated bacteria in both the study population but it washigher in non-diabetics (65.26%). Other isolated bacteria were S. aureus, S. saprophyticus, viridans streptococci, Moraxella sp, H. influenzae and Pseudomonas sp in different percentages among the both groups (Table-2). S. saprophyticus (4.21%) and Diphtheroids (2.11%) were isolated only in non-diabetic patients while S. pneumoniae (2.17%), Esch. coli (6.52%) and Enterobacter sp (8.3%) were isolated in diabetic patients only (Table-2). Table 2: Pattern of bacteria isolated from conjunctival swabs   The conjunctival sac is parasitized with microflora that changes dynamically throughout the life time because of its long-term exposure to the environment and these flora are part of the defense mechanism of the eye in preventing colonization by more pathogenic microorganisms.11 In the present study, conjunctival bacterial flora was isolated more frequently in diabetic patients (64%) than the non-diabetics (38%). Martin et al. (2004) also observed higher frequency of conjunctival culture positivity in diabetic group than those of nondiabetic group (94.18% vs. 73.33%).13 In their study, they have correlated the frequency of culture positivity with diabetic retinopathy and the frequent bacterial isolation in those patients indicated that retinopathy might be a factor for altered conjunctival flora.   1.    Snell RS and Lemn MA. Conjunctiva. In: Clinical anatomy of eye. 2nd edition. Blackwell Science, USA. 1998; 108-112. 3.    Todar K. The normal bacterial flora of humans, Online Text Book of Bacteriology. 2009; Available at kentodar@textbookofbacteriology.net. Accessed on 2/01/2012. 5.    Therese KL & Madhavan HN. Microbiological procedures for diagnosis of ocular infections, L & T Microbiology Research Centre, Vision Research Foundation l8, College Road, Chennai 600 006. 2004. 7.    Skarbez K, Priestley Y, Hoepf M and Koevary SB. Comprehensive review of the effects of diabetes on ocular health. Expert Rev Ophthalmology 2010; 5:   557–577. 9.    Cheesbrough M. Microbiological tests. In: District Laboratory Practice in Tropical Countries. Cambridge University Press 2000; 64-404. 11.  Liu J, Li J, Hu J and Xie H. Identification and quantitation of conjunctival aerobic bacterial flora from healthy residents at different ages in Southwest China. African J Microbiol Res 2011; 5: 192-197.       Impaired leucocyte functions in diabetic patients. Diabet Med 1997; 14: 29-34. 2026 Ibrahim Medical College. All rights reserved.