Dacryocystitis is an inflammation of the lacrimal sac. It occurred due to obstruction of the nasolacrimal duct.[1] The obstruction may be related to trauma, infection, inflammation, tumour, or mechanical obstruction (secondary acquired lacrimal drainage obstruction) [2], or it may be an idiopathic inflammatory stenosis (primary acquired nasolacrimal duct obstruction) [3]. Obstruction causes tears to become stuck in a pathologically closed lacrimal drainage system. This can lead to an infection of the sac.

There have also been reports of more severe cases, including meningitis, superior ophthalmic vein thrombosis, cavernous sinus thrombosis, orbital cellulitis with orbital abscess, necrotizing fasciitis, and complete blindness secondary to dacryocystitis. [4-6] Dacryocystitis has a variable etiology and epidemiological pattern depending on the period of time, place, and climate. It is essential to carry out comprehensive laboratory testing to identify the etiologic organism before beginning a specific course of antibiotics. Antibiotic resistance developed as a result of the widespread and indiscriminate use of antimicrobial drugs.

The antibiotic treatment for dacryocystitis varies from patient to patient based on age, disease stage, aetiological agent, and drug resistance pattern. Antibacterial resistance varies by location, depending on the spread of resistant strains and the use of antimicrobial treatments. [7] The selection of appropriate treatment and the reduction of the overuse of antimicrobial medicines would benefit from understanding the causes of dacryocystitis. As a result, the findings of this study will be useful to clinicians. This study's objectives were to isolate and identify the etiological agents from patients with dacryocystitis, identifying the antimicrobial susceptibility patterns of the isolated organisms

Study Type: Cross-sectional study.

Study Population: Patients attending the institute of ophthalmology and those admitted in IPD during the study duration were included in the study.

Study Area: The study was carried out in the Institute of Ophthalmology & Department of Microbiology, Jawaharlal Nehru Medical College, AMU, Aligarh.

Study Duration: From October 2018 to December 2020.

Data Collection: All the patients were examined by a group of ophthalmologists. Purulent materials expressed from the infected lacrimal sac were collected with the help of sterile cotton swab.  The clinical specimens were processed in the laboratory. Direct microscopy of Gram-stained smear was performed for all the collected specimens to differentiating between Gram positive and Gram-negative organisms, which were inoculated onto 5% Blood agar (BA), Chocolate agar (CA), MacConkey agar (MCA), Thioglycolate medium, and Brain-heart infusion broth (BHI). These were incubated at 37°C for 18-24 hours. The organism was identified based on morphology, culture characteristics, and various biochemical tests like Catalase, Oxidase, Tube and Slide coagulase, Hugh and Leifson (O/F), Voges-Proskauer, Methyl red, Nitrate reduction, Citrate utilisation, Urease production, Kligler iron, Indole and Phenylpyruvic acid tests.

Antibiotic susceptibility testing

The antibiotic susceptibility testing was done by the Kirby Bauer Disc diffusion method as per the Clinical and Laboratory Standards Institute (CLSI) guidelines, using the commercially available antibiotic discs from HiMedia (Mumbai, India).The antibiotics used for Gram-negative bacilli were amikacin (30μg), amoxicillin-clavulanic acid  (20/10 μg), cotrimoxazole (trimethoprim-sulphamethoxazole1.25/23.75μg), ceftriaxone (30 μg), meropenem (10μg), ceftazidime (30 μg), cefixime(15μg), cefoperazone (75 μg), cefepime (30 μg), pipercillin-tazobactum (100/10 μg), ceftazidime-clavulanic acid (30/ 10 μg). The antibiotics used for Gram-positive cocci included amikacin (30 μg), ampicillin (10 μg), cotrimoxazole (trimethoprim-sulphamethoxazole, 25/23.75 μg), clindamycin (2 μg), cefoxitin (30 μg), azithromycin(15  μg) and vancomycin (30 μg) for Staphylococcus species, and gentamicin (10 μg), amikacin (30 μg), ampicillin (10 μg), ciprofloxacin (5 μg), erythromycin (15 μg), gentamicin (120 μg), streptomycin (300 μg), and vancomycin (30 μg) for Streptococcus species. Cefoxitin (30μg) was used for the detection of MRSA.

Ethics: The Institutional Ethics Committee of Jawaharlal Nehru Medical College, Aligarh Muslim University, approved the study. Prior to their enrolment in the study, patients or their legal guardians (if applicable) gave their informed consent.

Data Management: IBM SPSS version 20.0 was used to analyse the data after it was imported from MS Excel (2010). The collected results are presented as frequencies and percentages.

Patient distribution: The age group of the patients in our study is presented in Table 1

Table 1: Distribution of Patients in the different Age groups

Bacteriological Profile: The study consisted of 67 patients in total. Out of the 67 samples collected, 53 (79.1%) showed positive microbial growth. A total of 55 microorganisms were isolated, with two specimens showing mixed growth. Most of the microorganisms found were Gram-positive bacteria. Staphylococcus aureus was the most commonly isolated species. There were 18 (32.72%) isolates of Gram-negative bacteria, with Pseudomonas aeruginous and Escherichia coli representing the most frequent Gram-negative bacteria. [Table 2]

Table 2: Bacteriological Profile of the Patient with Dacryocystitis

Antimicrobial susceptibility pattern:

For Gram-positive cocci

The antimicrobial susceptibility pattern of isolates is shown in graphs 1 &2. All Gram-positive isolates showed good susceptible to vancomycin (100%) and amikacin (85%). Among the Staphylococcus species, 69% were identified as MRSS (Methicillin-resistant Staphylococcus species). (Graph1)

For Gram-negative bacilli

Among all Gram-negative isolates, 71% were susceptible to meropenem, ceftriaxone-sulbactam and piperacillin-tazobactam, and susceptibility of levofloxacin, cotrimoxazole, and ceftriaxone was 42.9 %. (Graph 2)

Acquired nasolacrimal duct obstruction is commonly seen in elderly or middle-aged patients as reported in various previous studies. [8, 9] In the present study, the most common age group was over the middle-aged group, which accounted for 54.3 % of patients.

Out of 67 samples collected, 14 (20.89 %) cultures tested negative for microbial growth, various factors may be responsible, like the probability of anaerobic etiological agents, and other possible reasons may be the hidden use of antibiotics and unknown medications for negative culture.

Our study found different types of bacteria, including Gram-positive cocci, and Gram-negative species from positive culture. This variation was in accordance with previous studies on dacryocystitis microbiological analysis. [7, 9, 10].

In our study, the predominant causative agent is Staphylococcus aureus (40%: 22/55). The second most common cause is Streptococcus species, (21.8%: 12/55).  Other bacterial species like CONS 5.4% (3/55), Escherichia coli 9% (5/55), Pseudomonas aeruginosa 9% (5/55), Pseudomonas species 5.4% (3/55)  Klebsiella pneumoniae 7.2% (4/55), and  Klebsiella oxytoca 1.8% (1/55)  were also isolated.

In previous studies including Huber-Spitzy et al. (1992),  Chaudhry et al. (2005), Mills et al. (2007),  Bharathi et al. (2008), Ali et al. (2013), and Assefa et al. (2015) found that Gram-positive organisms dominate over Gram-negative organism in dacryocystitis.[7,11-15]

A surgical procedure dacryocystorhinostomy is used to treat nasolacrimal duct obstruction in dacryocystitis. Despite the surgical treatments, the risk of soft tissue infection increases fivefold in the absence of systemic antibiotics, which demonstrates the importance of antibiotics in the management of dacryocystitis. [16] The most susceptible antibiotics in the study by Assefa et al. were ceftriaxone (95.3%), erythromycin (84.2%), nalidixic acid (87.1%), and gentamicin (83.3%).[7] The antibiotics with the highest effects in the study by Kebede et al. were tetracycline (61.5%), erythromycin (68.1%), gentamicin (79.1%), and chloramphenicol (82.4%).[16] In this study, the most effective antibiotics were vancomycin (100%), followed by amikacin (85%), levofloxacin (54%), and cotrimoxazole for Gram-positive organisms. For Gram-negative organism meropenem (71%), ceftriaxone-sulbactam (71%), piperacillin-tazobactam(71%), and amikacin(57%). The disparity between studies suggests that there are significant differences in antibiotic susceptibility patterns across geographic areas due to regional pathogens.

According to available studies, the bacteria identified from patients with dacryocystitis vary based on their local distribution, prevalence, and antibiotic susceptibility patterns in distinct geographical regions. Our study identified Staphylococcus aureus as a prominent contributor to dacryocystitis. The susceptibility of antibiotics varied, demonstrating that vancomycin, levofloxacin, and amikacin were notably effective against gram-positive isolates, while meropenem, ceftriaxone-sulbactam, piperacillin-tazobactam, and amikacin exhibited susceptible against gram-negative isolates. This information is instrumental in establishing an informed and region-specific approach to the selection of antibiotics for the systemic treatment of dacryocystitis.

Limitations

This was a hospital-based study conducted at a tertiary care center; therefore, the findings may not be generalizable to the community , as the patient population in tertiary centers often represents more severe or referred cases. Consequently, the study is subject to selection bias. Furthermore, the relatively small sample size limits the statistical power of the study and may affect the precision of the results. Larger, multicentric studies are required to validate these findings and provide a more comprehensive understanding of the antimicrobial susceptibility patterns.

1. Iliff NT. Infections of the lacrimal drainage system. In: Peopse JS, Holland GN, Wilhelmus KR, editors. Ocular Infection and Immunity. St. Louis (MO): Mosby; 1996. p. 1346–1355.
2. Bartley GB. Acquired lacrimal drainage obstruction: an etiologic classification system, case reports, and a review of the literature. Part 1. Ophthal Plast Reconstr Surg. 1992; 8:237–242.
3. Linberg JV. Disorders of the lower excretory system. In: Milder B, Weil BA, editors. The Lacrimal System. New York: Appleton-Century-Crofts; 1983. p. 1–134.
4. Mauriello JA, Wasserman BA. Acute dacryocystitis: an unusual case of life-threatening orbital intraconal abscess with frozen globe. Ophthal Plast Reconstr Surg. 1996; 12:294–295.
5. Maheshwari R, Maheshwari S, Shah T. Acute dacryocystitis causing orbital cellulitis and abscess. Orbit. 2009; 28:196–199.
6. Schmitt NJ, Beatty RL, Kennerdell JS. Superior ophthalmic vein thrombosis in a patient with dacryocystitis-induced orbital cellulitis. Ophthal Plast Reconstr Surg. 2005; 21:387–389.
7. Assefa Y, Moges F, Endris M, et al. Bacteriological profile and drug susceptibility patterns in dacryocystitis patients attending Gondar University Teaching Hospital, Northwest Ethiopia. BMC Ophthalmol. 2015; 15(1):1–8.
8. Eshraghi B, Abdi P, Akbari M, Fard MA. Microbiologic spectrum of acute and chronic dacryocystitis. Int J Ophthalmol. 2014; 7(5):864–867.
9. Sun X, Liang Q, Luo S, Wang Z, Li R, Jin X. Microbiological analysis of chronic dacryocystitis. Ophthalmic Physiol Opt. 2005; 25(3):261–263.
10. Eslami F, Ghasemi Basir HR, Moradi A, Heidari Farah S. Microbiological study of dacryocystitis in northwest of Iran. Clin Ophthalmol. 2018; 12:1859–1864.
11. Chaudhry IA, Shamsi FA, Al-Rashed W. Bacteriology of chronic dacryocystitis in a tertiary eye care center. Ophthalmic Plast Reconstr Surg. 2005; 21(3):207–210.
12. Bharathi MJ, Ramakrishnan R, Maneksha V, Shivakumar C, Nithya V, Mittal S. Comparative bacteriology of acute and chronic dacryocystitis. Eye (Lond). 2008; 22(7):953–960.
13. Huber-Spitzy V, Steinkogler FJ, Huber E, Arocker-Mettinger E, Schiffbänker M. Acquired dacryocystitis: microbiology and conservative therapy. Acta Ophthalmol (Copenh). 1992; 70(6):745–749.
14. Mills DM, Bodman MG, Meyer DR, Morton AD; ASOPRS Dacryocystitis Study Group. The microbiologic spectrum of dacryocystitis: a national study of acute versus chronic infection. Ophthalmic Plast Reconstr Surg. 2007; 23(4):302–306.
15. Ali MJ, Joshi SD, Naik MN, Honavar SG. Clinical profile and management outcome of acute dacryocystitis: two decades of experience in a tertiary eye care center. Semin Ophthalmol. 2015; 30(2):118–123.
16. Kebede A, Adamu Y, Bejiga A. Bacteriological study of dacryocystitis among patients attending in Menelik II Hospital, Addis Ababa, Ethiopia. Ethiop Med J. 2010; 48(1):29–33.