Ear discharge is a prevalent otologic symptom associated with conditions such as acute otitis media, chronic otitis media (COM), and otitis externa. Among these, COM is a significant public health concern, particularly in developing countries, due to its association with long-term hearing impairment and intracranial complications if inadequately managed [1]. The condition is characterized by persistent or recurrent ear discharge through a perforated tympanic membrane lasting more than two weeks [2].

The etiological agents responsible for ear infections vary based on geographic region, environmental factors, and antibiotic prescribing patterns. Commonly implicated organisms include Pseudomonas aeruginosa, Staphylococcus aureus, Proteus species, and Escherichia coli [3,4]. In recent years, the emergence of antimicrobial resistance among these pathogens has complicated treatment, necessitating periodic surveillance of local bacterial profiles and susceptibility trends to guide empirical therapy effectively [5].

Additionally, the presence of comorbidities such as diabetes, hypertension, and thyroid disorders has been found to influence the pattern and severity of infection in COM patients [6]. These conditions may compromise host immunity, thereby increasing susceptibility to persistent infections and resistant bacterial strains [7].

Despite global efforts, data specific to certain regions—such as North Maharashtra—remain scarce. Therefore, the current study was undertaken to assess the bacteriological profile of discharging ear cases in this population, evaluate the antibiotic resistance patterns, and examine the relationship between bacterial isolates and underlying comorbidities.

Study Design and Setting

This was a cross-sectional observational study conducted over a period of six months at a tertiary care hospital located in North Maharashtra. The hospital serves as a referral centre for a wide range of otolaryngological disorders, particularly chronic ear infections.

Study Population

The study included 144 patients presenting to the ENT outpatient department with complaints of ear discharge. Participants of all age groups and genders who provided informed consent were considered eligible.

Inclusion Criteria

• Patients with active ear discharge at the time of presentation.
• Willingness to participate in the study.

Exclusion Criteria

• Patients who had received systemic or topical antibiotics within the previous one month.
• Patients with incomplete clinical records or who were unwilling to participate.

Clinical Assessment

Each patient underwent a detailed evaluation, including medical history, general examination, and local examination of the ear. Relevant findings such as duration of discharge, laterality, and presence of symptoms like hearing loss or pain were recorded.

Sample Collection and Processing

Using sterile cotton swabs, pus samples were collected aseptically from the discharging ear under otoendoscopic guidance. The samples were immediately transported to the microbiology laboratory for culture and sensitivity analysis.

Bacterial Culture and Identification

Swabs were inoculated on MacConkey agar and blood agar plates and incubated aerobically at 37°C for 24 hours. Bacterial growth was assessed, and isolates were identified using standard microbiological procedures, including colony morphology, Gram staining, and biochemical tests.

Antibiotic Susceptibility Testing

All isolates were subjected to antimicrobial sensitivity testing using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar. The results were interpreted in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines.

Statistical Analysis

Data were entered and analyzed using appropriate statistical software. Descriptive statistics were used to summarize demographic characteristics and bacteriological findings. The association between comorbidities and bacterial isolates was analyzed using the Chi-square test, with a p-value of <0.05 considered statistically significant.

A total of 144 patients with ear discharge were included in the study. The demographic distribution, bacterial isolates, antimicrobial resistance patterns, and association with comorbidities are summarized below.

Demographic Profile

Out of the 144 participants, 81 (56.3%) were male and 63 (43.7%) were female. The mean age of the patients was 39.67 ± 16.2 years. The highest incidence was observed in the 31–45 years age group (32.6%), followed by 16–30 years (27.8%) and 46–60 years (21.5%) (Table 1).

Table 1: Distribution of Patients by Age and Gender

Bacteriological Profile of Ear Discharge

Among the 144 samples, Pseudomonas aeruginosa was the most frequently isolated organism, identified in 66 cases (45.8%). Staphylococcus aureus was isolated in 27 cases (18.8%). Other bacteria included Proteus spp. (2.1%), Escherichia coli (2.1%), and Enterobacter spp. (2.1%). No growth was observed in 15 cases (10.4%) (Table 2).

Table 2: Frequency of Bacterial Isolates in Ear Discharge

Antibiotic Resistance Pattern

Resistance testing revealed that Pseudomonas aeruginosa showed high resistance to amoxicillin-clavulanic acid (84.8%), ciprofloxacin (60.6%), and ceftriaxone (57.6%). However, it remained sensitive to piperacillin-tazobactam, imipenem, and meropenem. Staphylococcus aureus demonstrated resistance to erythromycin (66.7%) and cefotaxime (48.1%) but was largely sensitive to linezolid, methicillin, and gentamicin (Table 3).

Table 3: Antibiotic Resistance Profile of Common Isolates

Association with Comorbidities

Among patients with comorbid conditions such as diabetes, hypertension, or thyroid dysfunction, Pseudomonas aeruginosa (53.1%) and Staphylococcus aureus (25.0%) remained the dominant isolates. A statistically significant association was found between the presence of comorbidities and specific bacterial isolates (P = 0.020) (Table 4).

Table 4: Bacterial Isolates among Patients with Comorbidities

Chronic otitis media (COM) remains a significant cause of preventable hearing loss globally, particularly in developing countries where limited healthcare access and delayed treatment are common issues [1]. This study aimed to evaluate the bacteriological profile and antibiotic susceptibility patterns in patients with discharging ears at a tertiary care hospital in North Maharashtra.

The majority of patients in the current study were male (56.3%), with a mean age of 39.67 years. These findings are consistent with previous research indicating that CSOM tends to be more prevalent in males and among individuals in the third and fourth decades of life [2,3]. The higher prevalence in males may be related to greater occupational exposure to environmental irritants among men and less frequent healthcare-seeking behaviour among females [4].

Pseudomonas aeruginosa was the most frequently isolated organism, found in 45.8% of samples. This aligns with previous studies from different regions of India and Africa, where P. aeruginosa is often reported as the predominant pathogen in CSOM [5–7]. The organism’s ability to form biofilms and thrive in moist environments contributes to its persistence and pathogenicity in chronic ear infections [8]. Staphylococcus aureus, the second most common isolate in our study (18.8%), has also been widely reported as a major contributor to ear infections [9].

Antibiotic resistance remains a growing concern. In the present study, P. aeruginosa showed high resistance to commonly used agents such as amoxicillin-clavulanic acid and ciprofloxacin, but retained sensitivity to piperacillin-tazobactam, imipenem, and meropenem. These findings are in line with previous surveillance studies indicating that P. aeruginosa has developed multidrug resistance in many tertiary care settings [10,11]. Similarly, S. aureus exhibited resistance to erythromycin and cefotaxime but was sensitive to linezolid and gentamicin, consistent with earlier reports [12].

The association between comorbidities and specific bacterial isolates observed in our study is notable. Patients with diabetes, hypertension, and thyroid disorders were more likely to harbor Pseudomonas and Staphylococcus species, with a statistically significant correlation (P = 0.020). This supports prior evidence suggesting that metabolic and immune-modulatory conditions predispose individuals to chronic and persistent infections [13]. Diabetic individuals, in particular, have altered host immunity, which may contribute to increased bacterial colonization and delayed healing [14].

The findings underscore the importance of continuous regional surveillance of bacterial pathogens and their resistance profiles. Empirical therapy should be guided by updated antibiograms to minimize treatment failure and prevent the development of further resistance [15]. Incorporating antibiotic stewardship programs and educating healthcare providers about rational antibiotic use is crucial in controlling resistance trends.

The study highlights Pseudomonas aeruginosa and Staphylococcus aureus as the predominant pathogens in patients with discharging ears, with notable resistance to commonly used antibiotics. The presence of comorbidities significantly influenced bacterial distribution. These findings emphasize the need for region-specific antibiotic policies and targeted therapy to ensure effective management of COM and prevent antimicrobial resistance.

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