AEROBIC FLORA OF THE NORMAL HUMAN
PURPOSE: The aim of this study was to evaluate the prevalence of conjunctival flora and
identify its types in normal conjunctiva.
METHOD: This study was carried out by the Department of Pathology at Civil Hospital
Hyderabad. The aim was to identify the presence of normal flora and distinguish the bacterial
types, in population sample of 1000 subjects.
Swabs were taken from conjunctiva of those patients who had no infection or redness in
Culture media used were sheep blood agar, chocolate agar, MacConkeys agar, fungal media,
mycobiotic agar and Sabouraud 4% dextrose agar.
The Gram-staining was done for each swab.
RESULTS: There were 475 Males and 525 Females patients from which swabs were taken.
Out of 1000 swab tests, 850 (85%) showed no growth, while 110 (10.1%) cases showed the
presence of normal bacterial flora in the conjunctiva, whereas 40 (4%) cases showed presence
of pathogenic organisms.
In 110 cases of normal flora, we found Staphylococcus epidermis (54.5%) as predominant
organism followed by Diphtheroids (23.6%).
No growth result indicates the absence of both useful flora as well as other pathogenic
CONCLUSIONS: In our study it was observed that amongst the normal conjunctival flora,
Staphylococcus epidermidis was the most common organism and may produce endophthalmitis.
Mixed cultures were also observed and some cases showed presence of pathogenic organisms
with normal looking eyes,
All these factors can lead to postoperative endophthalmitis. Hence prior elimination of
pathogens is necessary to prevent postoperative endophthalmitis.
Bacterial culture test must be practice to achieve safe surgery thereby preventing postoperative
KEY WORDS: Aerobic Flora, Conjunctival Sac.
The term “normal microbial flora” refers to population of microorganisms that dwell within
the eyes of healthy individuals. These microorganisms play an important and specific role
in maintaining health and normal conjunc