Prevalence of Gram-positive and negative bacteria associated with external ocular infection in Wasit province, Iraq

Abstract

Background: In developing countries, ocular infections are a significant public health concern, particularly bacterial infections, which are common. This research aimed to estimate how often Gram-positive and negative bacteria are present in individuals who have external ocular infections in Wasit province. Materials and Methods: One hundred twenty-one eye swabs were gathered from patients with various eye infections in the consulting clinics of AL-Zahra Hospital between October 1, 2021, and March 1, 2022. Various bacterial colonies with different morphological and biochemical characteristics were detected through growth testing. Results: Of all the external ocular samples collected, 56 (46.2%) had a positive culture for bacterial pathogens. Most of the isolated bacteria were Gram-positive, accounting for 73.2% (41 cases) of the total. Coagulase-negative Staphylococci (CoNS) were the most commonly identified Gram-positive bacteria, followed by Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus aureus, Staphylococcus lentus, Staphylococcus hominis spp. Novobiosepticus, Staphylococcus pseudintermedius, Staphylococcus lugdunesis, Staphylococcus gallinarum, Staphylococcus vitulinus, Staphylococcus cohnii, Streptococcus pneumoniae, Kocuria rosea, Micrococcus luteus, Leuconostoc mesenteroides, and, among which, Gram-negative bacteria accounted for 26.8% such as Klebsiella pneumonia, Proteus mirabilis, Enterobacter aerogenes, Pantoea spp., Yersinia enterocolitica, Citrobacter sedlakii, Pseudomonas aeruginosa, Pseudomonas oryzihabitans, and Sphingomonas paucimobilis. DNA extraction and their purity and concentration were confirmed using Nanodrop. A monoplex pattern of polymerase chain reaction (PCR) was employed to detect Gram-positive specific 16S rRNA. Conclusion: A majority of the bacterial strains identified in patients with ocular infections, particularly Gram-positive bacteria, also concluded that the largest percentage of eye infections was for patients who lived in rural areas, this explains the reason for the isolation of some bacterial species that inhabit animals such as S. lentus, S. gallinarum, S. pseudintermedius, S. vitulinus, S. cohnii, and L. mesenteroides. In addition, most of the bacterial species found in patients with eye infections were resistant to multiple drugs, indicating the development of multidrug-resistant bacteria in the study population, also concluded that the most prevalent forms of external ocular infections were blepharitis, followed by conjunctiva.