Staphylococcus Epidermidis is the Main Causative Agent of Conjunctivitis

Abstract

Background: Staphylococcus epidermidis is a gram-positive coccus, catalase positive, coagulase negative and non manittol fermenter, it is one of the main commensal microorganisms that colonizes the skin, nose and other sites in the body. It is considered nonpathogenic normal flora but when dislodged to other areas become opportunistic and causes severe infections due to biofilm formation particularly on extraordinary sites like urinary tract infections after catheter acquired infections Purpose: To determine the role of Staphylococcus epidermidis as one of the main causative agents of chronic conjunctivitis and its essential factor in increase antibiotic resistance and strong biofilm production in those patients. Objective: This study investigates the correlation between the colonization of Staphylococcus epidermidis in the body and chronic eye infections in patients with conjunctivitis. Methods: A total of 100 eye swab samples were enrolled in this study, collected from patients with conjunctivitis (n=50) and healthy individuals (n=50). Staphylococcus epidermidis was isolated from the eyes of those groups cultured on special media following standard operating procedures. Antibiotic susceptibility tests against 5 antibiotics by using disk diffusion method were done and biofilm was measured to all groups by using tissue culture plate method. Results: In this study, out of 100 samples, there were 36% males and 64% females respectively. A total of 81(81%) were colonized with Staphylococcus epidermidis includes, 31(38.2%) from healthy individuals and 50(61.8%) from patients with conjunctivitis while only 12(12%) were colonized with Staphylococcus aureus includes 8(8%) in healthy individuals and 4(4%) in conjunctivitis patients. Results of antibiotic sensitivity tests to 5 antibiotics revealed all Staphylococcus epidermidis isolates were MDR and high resistant to Methicillin (100%) and sensitive to Vancomycin (100%), also all Staphylococcus epidermidis mainly in conjunctivitis patients were strong biofilm producers much higher than Staphylococcus aureus and Staphylococcus epidermidis isolates in the healthy persons. Conclusions: Coagulase negative staphylococci represented by Staphylococcus epidermidis was the most common agent isolated from conjunctiva of Baghdad patients and the most common cause of these chronic infections in those patients accompanied with increase antibiotic resistance rates and strong biofilm production more than coagulase positive Staphylococcus aureus in healthy and infected persons.