Spectrum and Antibiogram of Bacteria in Chronic Suppurative Otitis Media and Biofilm Formation

Abstract

Context: Chronic suppurative otitis media (CSOM) is a common infection having a high prevalence rate of 7.8-16% in India and is one of the leading causes of conductive deafness particularly in the adolescent age group [1]. CSOM is frequently associated with multidrug-resistant organisms with the ability to form biofilm, which is an important virulence factor and results in treatment failure. Aims:The main objectives of the study are to identify the spectrum of bacteria associated with CSOM, their antibiotic sensitivity pattern, and to detect the biofilm formation.Methods: This was a prospective cross-sectional study at a tertiary care hospital. Patients upto the age of 80, having otorrhea for more than 6-12 weeks [2,3] and attending the ENT outpatient department were included. Samples of pus were collected from the deeper aspect of external auditory meatus and processed using standard techniques for culture and sensitivity. Biofilm detection was done. Results were compiled and statistically analysed.Results: Sixty samples were processed and 43 yielded positive cultures. Staphylococcus aureus was the predominant organism, followed by Pseudomonas aeruginosa. Biofilm formation was seen in 19 (44.84 per cent) of the organisms. Biofilms were formed predominantly by Staphylococcus aureus (47.36 per cent). Conclusion:Multidrug resistance has become increasingly common amongst the causative organisms of CSOM, this trend being particularly evident among biofilm producers. Therefore, screening for biofilm formation, along with the usual antibiogram, needs to be performed as a routine procedure in CSOM to effectively manage the situation by choosing an appropriate modality of treatment.

Microbiology of Chronic Suppurative Otitis Media: An update from a Tertiary Care Hospital in Bangladesh

“…Gram-negative bacteria accounted for higher isolation rate than gram-positive (55% vs 45%), which corroborates with many other studies. 5 , 6 , 17 , 18 The reason for higher prevalence could be the chronic nature of infection where gram-negative bacteria from external sources get access into the auditory canal, suppressing the gram-positive normal flora and eventually become predominant. The leading bacterial pathogen was S. aureus including 15% MRSA that corroborates well with a few studies.…”

“…Likewise, Ciprofloxacin, a frequently used fluroquinolone was also found to be less efficacious with resistance ranging from 35 to 50% against both gram-positive and negative isolates, which coincides to some but contradicts others. 6 , 11 , 19 Further, both gram-positive and gram-negative isolates showed 50 to 75% resistance against Amoxicillin/Clavulanate, which has long been used as the empirical drug of choice for CSOM. In a systematic review and meta-analysis, Tesfa et al .…”

“…2 , 3 In Bangladesh, the prevalence of CSOM was found to be 7.4 to 39.5% and it was 7.8 to 16% in India reported in recent studies. 4 - 6 Dispersal of bacteria from a biofilm in the middle ear could serve as a potential reservoir and explain the recurrent and chronic nature of CSOM with reduce efficacy of antibiotic treatment. 7 …”

Microbiology and Drug Susceptibility Pattern of Bacterial Isolates from Patients with Chronic Suppurative Otitis Media at a Tertiary Care Hospital in Somalia

“…14,17,18 Gram-negative bacterial growth was observed in 77.3% of the samples, similar to the rates reported in the literature. [19][20][21][22] Looking at the studies from African countries, Proteus species were the most common isolates, followed by Staphylococcus aureus. 14 In a study from Nigeria, Pseudomonas aeruginosa was isolated predominantly, followed in decreasing frequency by Staphylococcus aureus, Klebsiellaspp.…”