Chronic suppurative otitis media (CSOM) is an important cause of preventable hearing loss, particularly in the developing world which is also a reason of serious concern particularly in children because of long term effects on early communication, language development, auditory processing, educational process and physiological and cognitive development. Further CSOM can also progress and lead to the complications like intracranial or extracranial extension which needs an emergency mastoidectomy accounting for additional costs and expenditures for the patient and if not taken appropriate care might also take a death toll. Hence early microbiological diagnosis and testing for antibiotic susceptibility for bacterial isolates aids in initiating early prompt and effective treatment.¹¹

Rani RU et al., has reported that the majority of the participants were in the age group 0-15 yrs and the age of the study participants ranged from 3-70 yrs and 47% of them were males and 53.0% were females which are similar to the current study where majority were in the age group 0-20 yrs.¹² Similarly the disease was more common in the first and second decades of life as reported by Poorey VK and Iyer A.¹³

Prakash R et al., has observed mono-microbial growth in 57.8% samples, followed by 33.3% samples yielded polymicrobial growth, whereas, 8.82% samples showed no growth¹⁴ and Rangaiah ST et al., in their study single microbial isolate was found in 80%, multiple bacteria were isolated in 5.2% and 14.8% were reported with sterile culture or no growth of microbes similarly in the current study, 76.0% yielded single isolate, 18.0% yielded multiple isolates and remaining 6.0% of the cases reported with sterile culture or no growth of microbes.¹⁵

The study by Chandrashekhar M R et al., has reported in their study that Pseudomonas aeruginosa predominated (46.7%) the growth followed by Staphylococcus aureus 17.9%, Klebsiella species 12.2% and citrobacter species 11.51%. similar to the current study findings.¹⁶

Various studies have reported varied results with respect to the microbial culture. Some studies have reported Pseudomonas aeruginosa as the most commonly isolated organism in CSOM in few studies and Staphylococcus aureus as the most commonly isolated organism in CSOM in some other studies.^14-23

Rangaiah ST et al., have found no anaerobes in the culture which is similar to the present study findings and similarly, studies by Maji et al., Ibekwe et al., and Indudharan et al., also showed negligible anaerobic isolates in their study.^{15. 24-26}

In the current study, the most common species (27.7%) identified among the multiple isolates was Proteus and Klebsiella species, however in a study conducted by Garima et al.,the most common (75.0%) species were the combination of Pseudomonas and Klebsiella species. The proportions (14.0%) of Proteus and Klebsiella species identified by Garima et al., were less compared to the current study.²⁷ The disparity could be attributed to difference in methodology, sample size and prior use of antibiotics and also it is noted that different pathogens cause otitis media in different geographic localities.²⁸

Aspergillus species predominated of the fungal isolates, which was similar with the study findings conducted by Vaidya K et al and Shrestha et al. ^29,30

Pseudomonas aeruginosa was found to be the most common isolate in CSOM with cholesteatoma in a study by Rathore VS et al., similarly in the current study Pseudomonas aeruginosa was the only isolated organism among cases of CSOM with cholesteatoma^{. 31}

Upon analyzing the antibiotic sensitivity results it was evident that the antibiotics with the highest bacterial susceptibility in this study were gentamycin followed by ciprofloxacin and cefotaxime: this is in line with a study conducted by Garba BI et al who found highest bacterial susceptibility rate in this study were ciprofloxacin, ofloxacin and gentamicin. ²⁸

Most common organisms isolated were Pseudomonas aeruginosa followed by Staphylococcus aureus. Among them, Pseudomonas aeruginosa had highest sensitivity to Piperacillin (94.6%) followed by Gentamycin and Ciprofloxacin. The findings were similar to various studies by Garima et al (80%)²⁸, Malkappa et al (83%)³², Agarwal et al (85.4%)³³ which showed high sensitivity to betalactam and beta-lactamase inhibitors whereas according to the study findings of Kumar S et al³⁴ and Chakraborty et al³⁵, Pseudomonas aeruginosa isolates had shown resistance to piperacillin but sensitivity was moderately good for Gentamicin, and ciprofloxacin. The difference in the antibiotic susceptibility pattern may be due to prior antibiotic therapy which might have caused antibiotic resistance.

Staphylococcus aureus was highly susceptible to Gentamycin and Cotrimoxazole which is similar to the findings of Malkappa SK et al³², Gulati et al.,³⁶ and Mishra et al.³⁷ who also found Staphylococcus aureus sensitive to gentamicin.³² In the present study, gentamicin with high susceptibility pattern is more effective in treating CSOM as majority of pathogens in CSOM cases are susceptible to it.³⁸