Journal of Mazandaran University of Medical Sciences (Oct 2024)
Investigating the Microbiological Spectrum in Patients with Chronic Nasolacrimal Duct Obstruction in Bu-Ali Sina Hospital in 2023
Abstract
Background and purpose: Infection of the lacrimal sac (dacryocystitis) can lead to serious complications, including orbital cellulitis, orbital abscess, meningitis, and cavernous sinus thrombosis, all of which pose significant threats to human health. This condition is often associated with nasolacrimal duct obstruction, which prevents normal tear drainage and creates an environment conducive to microbial growth. Timely identification of the causative agents of dacryocystitis is critical, as untreated or improperly managed infections can rapidly worsen, leading to systemic infections or even life-threatening conditions. This study aims to investigate the spectrum of microbiological agents causing dacryocystitis to control infection and provide appropriate treatment for patients with chronic nasolacrimal duct obstruction. Materials and methods: This cross-sectional study included patients diagnosed with chronic dacryocystitis who candidated for dacryocystorhinostomy (DCR) surgery. Routine ophthalmic examinations, including visual acuity, slit-lamp examination, and fundoscopy, were performed for all patients. Ocular discharge samples were sent to the laboratory at the Pediatric Infectious Disease Research Centre, Bu-Ali Sina Hospital, Sari. Each sample was incubated in blood agar, chocolate agar, EMB, and Sabouraud dextrose agar under aerobic conditions at 37°C for 24 hours and simultaneously in chocolate agar and blood agar under anaerobic conditions at 37°C for 48 hours. Catalase tests were used to distinguish Staphylococcus from Streptococcus bacteria, coagulase tests to differentiate Staphylococcus aureus from other Staphylococcus species, and oxidase tests to identify Pseudomonas and other Gram-negative bacteria. For detecting fungal infections, samples were stored on Sabouraud dextrose agar at 25-27°C for two weeks. Gram staining was performed on observed colonies, followed by microbiological diagnostic and differential tests based on bacterial species. Data were analyzed using SPSS software, described as means, and compared using the chi-squared test. Results: Of the 50 patients with chronic dacryocystitis included in the study, with a mean age of 56.9±15.28 years (range, 31 to 86 years), 34(68%) were female, and 16(32%) were male. Gram-positive bacteria accounted for 42 cases (84%) of isolated organisms, while gram-negative bacteria accounted for 8 cases (16%). Pus reflux was detected in 84% of cases, significantly more often with gram-positive organisms(P=0.03). The most common pathogens were Staphylococcus epidermidis (22 cases, 44%), Staphylococcus aureus (10 cases, 20%), and Streptococcus pneumoniae (6 cases, 12%). No significant correlations were found between sex and age with the number and type of organisms (P=0.77). Conclusion: Gram-positive bacteria are the main cause of chronic dacryocystitis infections, and demographic factors such as age and gender do not influence the type of infection. Staphylococcus epidermidis and Staphylococcus aureus have been identified as the predominant pathogens responsible for this condition. Understanding the microbiological spectrum can improve disease diagnosis and lead to more effective treatment strategies. This information is essential to help clinicians select appropriate, targeted antimicrobial treatments to more effectively control infections, reduce the risk of antimicrobial resistance, prevent serious complications and systemic infections, and ultimately improve patient outcomes.
