Samina Thapa1, Nabaraj Adhikari2, Binod Dhungel2, Madhu Thapa3, Upendra Thapa Shrestha2, Megha Raj Banjara2, Komal Raj Rijal2* and Prakash Ghimire2
1Kantipur College of Medical Sciences, Sitapaila, Kathmandu, Nepal
2Central Department of Microbiology, Tribhuvan University, Kirtipur, Nepal
3BP Koirala Lions Center for Ophthalmic Studies, Institute of Medicine, Tribhuvan University, Kirtipur, Nepal
*Corresponding Author: Komal Raj Rijal, Associate Professor, Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal.
Received: April 05, 2020; Published: May 28, 2020
Introduction: Ocular infections constitute a significant portion of curable eye diseases. However, in developing countries like Nepal, bacterial and fungal spectrum is not well established for ocular infections. Therefore, ocular infections still remain as the major cause of blindness. This study was sought determine the bacterial and fungal etiology of various ocular infections and assess the antibiotic susceptibility pattern of the bacterial pathogens.
Methods: This cross-sectional study was conducted at BP Koirala Lions Center for Ophthalmic Studies, Kathmandu, Nepal from June 2012 through April 2013. Various ophthalmic specimens of clinical values such as the corneal scraps, conjunctival swab and eye pus and biopsy materials were collected aseptically and processed for culture. After sufficient incubation, isolates were identified by colony morphology, Gram staining and relevant biochemical tests. Identified bacteria; isolates were then subjected under Antibiotic Susceptibility test (AST) by modified Kirby-Bauer disc diffusion method to determine Multi Drug Resistant (MDR) isolates and Minimum Inhibitory Concentration (MIC).
Results: A total number of 810 ocular specimens, mainly from the case of conjunctivitis (644/810) were processed. Of which, 31.97% (270/810) showed growth on culture medium: 267 (98.85%) were bacterial, 2 (0.77%) were fungal (Penicillium spp and Fusarium spp) and 1 (0.38%) was yeast (Rhodotorula) isolate. Gram positives alone accounted for 96.25% (257/267) among bacterial isolates. Staphylococcus aureus (52.96%) and Escherichia coli (1.48%) were the most common Gram positive and Gram-negative isolates respectively. Gram positive isolates showed resistance to ciprofloxacin (39.29%), cephalexin (38.13%) and amikacin (31.52%) while gram negatives were resistant to cefazolin (80%). All isolates of E. coli, Hemophilus influenzae and Serratia spp together with 48.95% of S. aureus were MDR. Among 5 methicillin resistant S. aureus (MRSA) isolates, 2 isolates were vancomycin intermediate S. aureus (VISA). Further, the minimum inhibitory concentration (MIC) break points for S. aureus to chloramphenicol, ciprofloxacin and vancomycin were also determined.
Conclusion: Conjunctivitis among adults was the most prevalent case found so far, yielding higher culture positivity. Along with MDR bacterial agents, fungal agents were observed to be posing significant threat in the disease management. Early diagnosis, proper management and empirical treatment are advised to prevent infections related blindness.
Keywords: Ocular Infections; Conjunctivitis; AST; MDR; MRSA; VISA; MIC
Citation: Komal Raj Rijal., et al. “Etiology of Ocular Infections and Minimum Inhibitory Concentration of Multidrug- Resistant Staphylococcus aureus Isolates to Vancomycin, Ciprofloxacin and Chloramphenicol". Acta Scientific Microbiology 3.6 (2020): 134-145.
Copyright: © 2020 Komal Raj Rijal., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.