Cause Of Deafness Research Articles

The Genetic Basis of Nonsyndromic Hearing Loss in Indian and Pakistani Populations.

Deafness encompasses a series of etiologically heterogeneous disorders with mutations in more than 400 independent genes. However, several studies indicate that a large proportion of both syndromic and nonsyndromic forms of deafness in the racially diverse Indian and Pakistani populations are caused by defects in just a few genes. In these countries, there is a strong cultural preference for consanguineous marriage and an associated relatively high prevalence of genetic disorders. The current Indian population is approximately 1.2 billion and it is estimated that 30,000 infants are born with congenital sensorineural hearing loss (HL) each year. The estimated rate of profound bilateral HL is 1.6 per 1000 in Pakistan and 70% of this HL arises in consanguineous families. Knowledge of the genetic cause of deafness within a distinct population is important for accurate genetic counseling and early diagnosis for timely intervention and treatment options. Many sources and technologies are now available for the testing of hearing efficiency. Population-based screening has been proposed as one of the major strategies for translating genetic and genomic advances into population health gains. This review of the genetics of deafness in Indian and Pakistani populations deals with the major causes of deafness in these countries and prospectives for reducing the incidence of inherited deafness.

Effect of Growth Factor Supplementation on the Hair Cell Specific Markers of Cells Harvested from Basilar Membrane.

Loss of auditory hair cells is a major cause of deafness. The presence of auditory progenitor cells in the inner ear raises the hope for mammalian inner ear cell regeneration. In this study, we aimed to investigate the effect of growth factor supplementations, namely a combination of epidermal growth factor (EGF), insulin-like growth factor (IGF), and beta (β)-fibroblast growth factor (βFGF), on the expression of hair cell-specific markers by cells harvested from the cochlear membrane. This would provide an insight into the capability of these cells to differentiate into hair cells. EGF, IGF, and βFGF were supplemented into the culture medium. The cells were evaluated by morphology, growth kinetic, gene expression, and protein expression. The cultured cells of mouse basilar membrane were spindle shaped. Growth factors-enriched medium promotes a significantly higher proliferative activity than the basic culture medium but did not alter the cell morphology. Growth factors-enriched medium did not show any significant differences in the protein expression of the hair cell-specific markers myosin VIIa and calretinin and the stem-cell marker nestin. Gene expression analysis showed that the expression of the hair cell-specific genes myosin VIIa and calretinin as well as the stem cell genes nestin, Rex1, and Sox2 was reduced after the cells were passaged in the growth factor-supplemented medium. Cells in the basic medium expressed a significantly higher level of hair cell-specific genes at certain passages. Growth factor supplementation could not maintain the expression of hair cell-specific markers by cells obtained from the cochlear membrane.

Large vestibular aqueduct syndrome: Impedance changes over time with different cochlear implant electrode arrays

ObjectivesThe aim of this study was to assess if large vestibular aqueduct syndrome (LVAS), with the increase in perilymphatic pressure, affects impedance changes over time with different types of Cochlear® implant electrode arrays Contour, Straight, and CI 422. To report speech perception outcomes for these cochlear implant recipients.MethodsRetrospective case review of impedance levels and categories of auditory performance. Impedance data were collected at switch on, 1 month, 3, 6, 12, and 24 months after cochlear implantation and compared with control (non-LVAS cochlear implant recipient) data for each array type. Forty-seven patients with exclusive LVAS and no other vestibulocochlear abnormalities or other identifiable cause of deafness were eligible for inclusion in the study.ResultsIn LVAS patients, there was a significant difference in impedance between the three types of device (P < 0.0001). Time since switch on was associated with a decrease in impedance for all three devices (P < 0.0001). The mean impedance reduced between switch on and 1 month and remained relatively constant thereafter. Sound variation with softening of sounds was seen in four CI 422 (Straight Research Array) recipients due to ongoing fluctuations in electrode compliance.DiscussionFor all three array types, there was no significant difference in the mean impedance between the LVAS patients and controls over the first 12 months. In keeping with previous studies cochlear implant recipients with LVAS hear very well through the cochlear implant.

C-Raf deficiency leads to hearing loss and increased noise susceptibility.

The family of RAF kinases transduces extracellular information to the nucleus, and their activation is crucial for cellular regulation on many levels, ranging from embryonic development to carcinogenesis. B-RAF and C-RAF modulate neurogenesis and neuritogenesis during chicken inner ear development. C-RAF deficiency in humans is associated with deafness in the rare genetic insulin-like growth factor 1 (IGF-1), Noonan and Leopard syndromes. In this study, we show that RAF kinases are expressed in the developing inner ear and in adult mouse cochlea. A homozygous C-Raf deletion in mice caused profound deafness with no evident cellular aberrations except for a remarkable reduction of the K+ channel Kir4.1 expression, a trait that suffices as a cause of deafness. To explore the role of C-Raf in cellular protection and repair, heterozygous C-Raf+/− mice were exposed to noise. A reduced C-RAF level negatively affected hearing preservation in response to noise through mechanisms involving the activation of JNK and an exacerbated apoptotic response. Taken together, these results strongly support a role for C-RAF in hearing protection.Electronic supplementary materialThe online version of this article (doi:10.1007/s00018-015-1919-x) contains supplementary material, which is available to authorized users.

Sphingosine 1-phosphate signaling pathway in inner ear biology. New therapeutic strategies for hearing loss?

Hearing loss is one of the most prevalent conditions around the world, in particular among people over 60 years old. Thus, an increase of this affection is predicted as result of the aging process in our population. In this context, it is important to further explore the function of molecular targets involved in the biology of inner ear sensory cells to better individuate new candidates for therapeutic application. One of the main causes of deafness resides into the premature death of hair cells and auditory neurons. In this regard, neurotrophins and growth factors such as insulin like growth factor are known to be beneficial by favoring the survival of these cells. An elevated number of published data in the last 20 years have individuated sphingolipids not only as structural components of biological membranes but also as critical regulators of key biological processes, including cell survival. Ceramide, formed by catabolism of sphingomyelin (SM) and other complex sphingolipids, is a strong inducer of apoptotic pathway, whereas sphingosine 1-phosphate (S1P), generated by cleavage of ceramide to sphingosine and phosphorylation catalyzed by two distinct sphingosine kinase (SK) enzymes, stimulates cell survival. Interestingly S1P, by acting as intracellular mediator or as ligand of a family of five distinct S1P receptors (S1P1–S1P5), is a very powerful bioactive sphingolipid, capable of triggering also other diverse cellular responses such as cell migration, proliferation and differentiation, and is critically involved in the development and homeostasis of several organs and tissues. Although new interesting data have become available, the information on S1P pathway and other sphingolipids in the biology of the inner ear is limited. Nonetheless, there are several lines of evidence implicating these signaling molecules during neurogenesis in other cell populations. In this review, we discuss the role of S1P during inner ear development, also as guidance for future studies.

Non-manifesting AHI1 truncations indicate localized loss-of-function tolerance in a severe Mendelian disease gene.

Determination of variant pathogenicity represents a major challenge in the era of high-throughput sequencing. Erroneous categorization may result if variants affect genes that are in fact dispensable. We demonstrate that this also applies to rare, apparently unambiguous truncating mutations of an established disease gene. By whole-exome sequencing (WES) in a consanguineous family with congenital non-syndromic deafness, we unexpectedly identified a homozygous nonsense variant, p.Arg1066*, in AHI1, a gene associated with Joubert syndrome (JBTS), a severe recessive ciliopathy. None of four homozygotes expressed any signs of JBTS, and one of them had normal hearing, which also ruled out p.Arg1066* as the cause of deafness. Homozygosity mapping and WES in the only other reported JBTS family with a homozygous C-terminal truncation (p.Trp1088Leufs*16) confirmed AHI1 as disease gene, but based on a more N-terminal missense mutation impairing WD40-repeat formation. Morpholinos against N-terminal zebrafish Ahi1, orthologous to where human mutations cluster, produced a ciliopathy, but targeting near human p.Arg1066 and p.Trp1088 did not. Most AHI1 mutations in JBTS patients result in truncated protein lacking WD40-repeats and the SH3 domain; disease was hitherto attributed to loss of these protein interaction modules. Our findings indicate that normal development does not require the C-terminal SH3 domain. This has far-reaching implications, considering that variants like p.Glu984* identified by preconception screening ('Kingsmore panel') do not necessarily indicate JBTS carriership. Genomes of individuals with consanguineous background are enriched for homozygous variants that may unmask dispensable regions of disease genes and unrecognized false positives in diagnostic large-scale sequencing and preconception carrier screening.

A study of deafness-related genetic mutations as a basis for strategies to prevent hereditary hearing loss in Hebei, China.

Hearing loss is the most common sensory disorder, and at least 50% of cases are due to a genetic etiology. Two-thirds of individuals with congenital deafness are nonsyndromic. Among the nonsyndromic forms, the large majority are monogenic autosomal recessive traits. The current work summarizes mutations in the GJB2, SLC26A4, 12SrRNA, and GJB3 and their prevalence in 318 students with autosomal recessive nonsyndromic hearing loss at schools for the deaf or special needs schools in 9 cities in Hebei Province, China. Deafness gene mutations were identified in 137 students via a gene chip, time-of-flight mass spectrometry, fluorescence quantitative PCR, and gene sequencing. Mutations were detected at a rate of 43.08%. A homozygous mutation of the GJB2 gene was found in 16 students (5.03%), a heterozygous mutation of that gene was found in 38 (11.95%), a homozygous mutation of the SLC26A4 gene was found in 22 (6.92%), a heterozygous mutation of that gene was found in 59 (18.55%), and a heterozygous mutation of the mitochondrial 12SrRNA gene was found in 2 (0.63%). In addition, there were 15 families in which a student's parents had normal hearing. Compound heterozygous mutations of the GJB2 gene were found in 3 families (20%) and mutations of the SLC26A4 gene were found in 9 (60%). Thus, this study has provided a molecular diagnostic basis for the causes of deafness, and this study has also provided a scientific basis for the early prevention of and intervention in deafness.

Temporalis muscle fascia and cartilage palisade technique of type 1 tympanoplasty: A comparison

Background: Chronic suppurative otitis media is one of the common causes of deafness in india and occupies a considerable amount of clinic and operating time of otolaryngologists. Materials and Methods: This was a prospective study containing 50 patients, which was further divided into two groups of 25 patient each. One group was cartilage palisade technique group and other was temporalis fascia technique group (TFT group). Detailed history and examination along with pure tone audiometry was performed. Pre- and postoperative hearing results and graft uptake were compared. All surgeries were performed through the post aural approach. Cartilage was harvested from cymba concha and fascia from temporalis muscle. Results: Hearing improved significantly when either of the technique was used. Though this was slightly better, but stastically insignificant in TFT. there was no significant difference in the graft uptake rates, but it was better in cases of Eustachian tube dysfunction when cartilage palisades were used. Conclusion: There was no statistically significant difference in results in terms of success and auditory function but cartilage palisade technique gave better results in specific conditions like Eustachian tube dysfunction.

Etiology Profile of the Patients Implanted in the Cochlear Implant Program

Hearing loss in children constitutes a considerable handicap because it is an invisible disability and compromises optimal development and personal achievement of a child. The period from birth to 5 years of life is critical for the development of speech and language; therefore, there is need for early identification and assessment of hearing loss and early rehabilitation in infants and children. Cochlear implants are the treatment of choice for patients with severe to profound sensorineural hearing loss. The goal of the present study was to investigate the different hearing impairment etiologies of patients implanted in cochlear implant program. The hospital based interventional study was conducted in the Department of Otorhinolaryngology, SMS Medical College, Jaipur from July 2011 to Dec. 2013. Present study included 60 prelingually deafened patients who attended ENT OPD and underwent cochlear implant. The most common cause of deafness in our study was acquired (56.66%), which predominantly included perinatal risk factors (64.70%), followed by prenatal risk factors (41.17%). The second common cause was hereditary (26.66%), followed by unknown (16.66%). Infection and ototoxic drug history were the most common risk factors in prenatal and postnatal group. The most common perinatal cause was low birth weight and prematurity.

Mitochondrial m.1584A 12S m62A rRNA methylation in families with m.1555A>G associated hearing loss.

The mitochondrial DNA mutation m.1555A>G predisposes to hearing loss following aminoglycoside antibiotic exposure in an idiosyncratic dose-independent manner. However, it may also cause maternally inherited hearing loss in the absence of aminoglycoside exposure or any other clinical features (non-syndromic hearing loss). Although m.1555A>G was identified as a cause of deafness more than twenty years ago, the pathogenic mechanism of this mutation of ribosomal RNA remains controversial. Different mechanistic concepts have been proposed. Most recently, evidence from cell lines and animal models suggested that patients with m.1555A>G may have more 12S rRNA N6, N6–dimethyladenosine (m62A) methylation than controls, so-called ‘hypermethylation’. This has been implicated as a pathogenic mechanism of mitochondrial dysfunction but has yet to be validated in patients. 12S m62A rRNA methylation, by the mitochondrial transcription factor 1 (TFB1M) enzyme, occurs at two successive nucleotides (m.1584A and m.1583A) in close proximity to m.1555A>G. We examined m62A methylation in 14 patients with m.1555A>G, and controls, and found all detectable 12S rRNA transcripts to be methylated in both groups. Moreover, different RNA samples derived from the same patient (lymphocyte, fibroblast and lymphoblast) revealed that only transformed cells contained some unmethylated 12S rRNA transcripts, with all detectable 12S rRNA transcripts derived from primary samples m62A-methylated. Our data indicate that TFB1M 12S m62A rRNA hypermethylation is unlikely to be a pathogenic mechanism and may be an artefact of previous experimental models studied. We propose that RNA methylation studies in experimental models should be validated in primary clinical samples to ensure that they are applicable to the human situation.

C.G2114A MYH9 mutation (DFNA17) causes non-syndromic autosomal dominant hearing loss in a Brazilian family.

We studied a family presenting 10 individuals affected by autosomal dominant deafness in all frequencies and three individuals affected by high frequency hearing loss. Genomic scanning using the 50k Affymetrix microarray technology yielded a Lod Score of 2.1 in chromosome 14 and a Lod Score of 1.9 in chromosome 22. Mapping refinement using microsatellites placed the chromosome 14 candidate region between markers D14S288 and D14S276 (8.85 cM) and the chromosome 22 near marker D22S283. Exome sequencing identified two candidate variants to explain hearing loss in chromosome 14 [PTGDR – c.G894A:p.R298R and PTGER2 – c.T247G:p.C83G], and one in chromosome 22 [MYH9, c.G2114A:p.R705H]. Pedigree segregation analysis allowed exclusion of the PTGDR and PTGER2 variants as the cause of deafness. However, the MYH9 variant segregated with the phenotype in all affected members, except the three individuals with different phenotype. This gene has been previously described as mutated in autosomal dominant hereditary hearing loss and corresponds to DFNA17. The mutation identified in our study is the same described in the prior report. Thus, although linkage studies suggested a candidate gene in chromosome 14, we concluded that the mutation in chromosome 22 better explains the hearing loss phenotype in the Brazilian family.

Noise-induced hearing loss in small-scale metal industry in Nepal.

There has been no previous research to demonstrate the risk of noise-induced hearing loss in industry in Nepal. Limited research on occupational noise-induced hearing loss has been conducted within small-scale industry worldwide, despite it being a substantial and growing cause of deafness in the developing world. The study involved a cross-sectional audiometric assessment, with questionnaire-based examinations of noise and occupational history, and workplace noise level assessment. A total of 115 metal workers and 123 hotel workers (control subjects) were recruited. Noise-induced hearing loss prevalence was 30.4 per cent in metal workers and 4.1 per cent in hotel workers, with a significant odds ratio of 10.3. Except for age and time in occupation, none of the demographic factors were significant in predicting outcomes in regression analyses. When adjusted for this finding, and previous noise-exposed occupations, the odds ratio was 13.8. Workplace noise was significantly different between the groups, ranging from 65.3 to 84.7 dBA in metal worker sites, and from 51.4 to 68.6 dBA in the control sites. Metal workers appear to have a greater risk of noise-induced hearing loss than controls. Additional research on occupational noise-induced hearing loss in Nepal and small-scale industry globally is needed.

Experiences and Results from Cochlear Implantation in Patients with Long Duration of Deafness

Objective: The aim of the present study was to gauge factors that influence the outcome of cochlear implants (CI) in patients who have been deaf for an extended period. Patients and Methods: Twelve adult cases (13 ears) were operated on at the CI unit in Uppsala during the period of 2002-2013. These patients had a deafness duration ranging between 20 and 72 years in the implanted ear and severe to profound hearing loss or deafness in the other ear. Data concerning pre- and postoperative speech perception, deafness duration, hearing/deafness duration in the contralateral ear, age at implantation, intraoperative electrophysiological measurements, cause of deafness, and user status were collected. Results: Eleven of 12 patients (13 ears) benefitted from CI treatment. Conclusion: The overall hearing experience, deafness duration, and age at onset of deafness are important issues to consider prior to CI.

Connexin gene mutations among ugandan patients with nonsyndromic sensorineural hearing loss

Congenital deafness occurs in approximately 1 in 1,000 live births, and 50% of these cases are hereditary. Connexin mutations have been identified as the most common cause of hereditary hearing loss in many populations. The prevalence of this mutation in African patients has not been adequately studied. The objective of this study was to determine the prevalence of connexin 26 and 30 mutations in a population of hearing-impaired patients from Uganda. This is an observational study. Coding regions of both GJB2 and GJB6, noncoding exon 1 of GJB2, and 30 nucleotides of intronic sequence bordering the exons were analyzed in 126 subjects from Uganda with confirmed bilateral, severe-to-profound sensorineural hearing loss. All variants were analyzed for possible clinical significance using a combination of database searches and in silico tools. Complete sequence data were obtained on 115/126 individuals; 11 had only partial or no results. Only one reported pathogenic variant was found in GJB2 (c.208C>G; p.Pro70Ala) and none in GJB6. Three reported variants and two novel variants within intron 1 of GJB2 and two variants within exon 3 of GJB6 were also found. None of the most common types of deletions in the GJB2 gene (c.35delG, c.167delT or c.235delC) were found in this large cohort of deaf children from Uganda. This prompts a search for genetic causes of deafness among this and other previously studied African populations.

Computed tomography features of luetic osteitis (otosyphilis) of the temporal bone

We report a missed case of otosyphilis presenting as otic capsule lucencies on temporal bone computed tomography. A 58-year-old woman presented with a 15-year history of bilateral, mixed hearing loss together with otic capsule lucencies, subsequently confirmed as otosyphilis. A literature review of otosyphilis was undertaken based on a PubMed search of studies published between 1988 and 2012, using the key words 'otosyphilis', 'otodystrophy', 'otic capsule lucencies' and 'luetic osteitis'. Although rare, otosyphilis is important to recognise as it is one of the few treatable causes of deafness when diagnosed early. The differentiating computed tomography features of luetic osteitis (otosyphilis) of the temporal bone have only rarely been described. We emphasise how these imaging features can be used to distinguish the rare but treatable condition of luetic osteitis from other, more common conditions with similar imaging findings.

Noise-induced hearing loss

Noise-induced hearing loss is the permanent hearing impairment that results from prolonged exposure to high levels of noise. Hearing loss caused by recreational and occupational noise exposure is the second-most-common cause of sensorineural hearing loss after presbycusis. Noise exposure is a potentially avoidable cause of deafness and the World Health Organisation recommends integrating elements of prevention, diagnosis, education, hearing promotion and conservation into primary care.

Chapter 15 - Congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infection, the most common congenital viral infection worldwide, occurs in approximately 1% of infants. Most congenitally infected infants have no long-term sequelae related to CMV infection. Approximately 10% have sensorineural hearing loss or neurologic deficits, including cerebral palsy, epilepsy, and cognitive impairment. Because of the high prevalence of congenital CMV infection, CMV is the most common non-genetic cause of deafness in children and an important cause of permanent neurodevelopmental disabilities. Treatment with ganciclovir has modest beneficial effects on outcome; no vaccine is currently available to prevent congenital CMV infection.

Endogenous Differences in Cochlear Sensory and Supporting Cell Mitochondrial Metabolism Bias Free Radical Production during Ototoxin Exposure

Aminoglycosides, including gentamicin (GM), are the most frequently used antibiotics in the world despite irreversible cochlear damage and hearing loss associated with their use. Although there are numerous causes of deafness, reactive oxygen species (ROS) are key regulators of multiple pathologies including: ototoxicity, noise-induced and age-related hearing loss. Unfortunately, the source of these cell-damaging ROS remains controversial. Given that ROS are normal byproducts of ATP synthesis, intrinsic differences in cochlear sensory (inner and outer hair cell, I/OHC) and supporting (pillar) cell mitochondrial metabolism may explain why high-frequency OHCs are profoundly sensitive to a host of challenges. Mitochondrial metabolism was compared in low-frequency and high-frequency IHCs, OHCs and pillar cells from acutely cultured cochlear explants. Intensity-based changes in the metabolic intermediate, nicotinamide adenine dinucleotide (NADH), were used to measure endogenous, mitochondrial toxin and GM-induced differences in sensory and supporting cell mitochondrial metabolism. Sensory cell mitochondrial metabolism was significantly enhanced relative to supporting cells. Despite similar amounts of mitochondria in IHCs and OHCs, endogenous levels of NADH were greatest in high-frequency OHCs. Metabolic profiling of NADH metabolism revealed basal turn, high-frequency OHCs to be metabolically responsive to a number of changes in their microenvironment including metabolic toxins and GM, while high-frequency IHCs, low-frequency I/OHCs and, pillar cells are substantially less sensitive. DHR-123 was used to detect sensory and supporting cell ROS production during GM exposure. Within 30 minutes of GM application, ROS are dramatically and specifically increased in high-frequency sensory cells. GM-induced changes in mitochondrial metabolism and cell-damaging free radical production were greatest in high-frequency OHCs. This metabolic predisposition biases basal turn OHC responses to a variety of cochlear insults, particularly those involving energy metabolism and ROS production.

Mutations in TBC1D24, a Gene Associated With Epilepsy, Also Cause Nonsyndromic Deafness DFNB86

Inherited deafness is clinically and genetically heterogeneous. We recently mapped DFNB86, a locus associated with nonsyndromic deafness, to chromosome 16p. In this study, whole-exome sequencing was performed with genomic DNA from affected individuals from three large consanguineous families in which markers linked to DFNB86 segregate with profound deafness. Analyses of these data revealed homozygous mutation c.208G>T (p.Asp70Tyr) or c.878G>C (p.Arg293Pro) in TBC1D24 as the underlying cause of deafness in the three families. Sanger sequence analysis of TBC1D24 in an additional large family in which deafness segregates with DFNB86 identified the c.208G>T (p.Asp70Tyr) substitution. These mutations affect TBC1D24 amino acid residues that are conserved in orthologs ranging from fruit fly to human. Neither variant was observed in databases of single-nucleotide variants or in 634 chromosomes from ethnically matched control subjects. TBC1D24 in the mouse inner ear was immunolocalized predominantly to spiral ganglion neurons, indicating that DFNB86 deafness might be an auditory neuropathy spectrum disorder. Previously, six recessive mutations in TBC1D24 were reported to cause seizures (hearing loss was not reported) ranging in severity from epilepsy with otherwise normal development to epileptic encephalopathy resulting in childhood death. Two of our four families in which deafness segregates with mutant alleles of TBC1D24 were available for neurological examination. Cosegregation of epilepsy and deafness was not observed in these two families. Although the causal relationship between genotype and phenotype is not presently understood, our findings, combined with published data, indicate that recessive alleles of TBC1D24 can cause either epilepsy or nonsyndromic deafness.

Aerobic bacteriological profile and their antibiotic susceptibility in Chronic Suppurative Otitis Media in patients from Mangalore, Karnataka State

Chronic suppurative otitis media is an infection of the middle ear and mastoid cavity. It is one of the most common causes of deafness. Low social-economic status, overcrowding, malnutrition and poor hygiene are the common risk factors and it commonly affects infants and children. The common pathogens responsible are Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Aspergillus species, Candida species etc. Several studies similar to this have been done previously from various regions of our country and also from several parts of the world. There are no studies done recently from this region to determine the bacteriological profile of aerobic bacteria and their antibiotic susceptibility in this region. The study was done for six months and the sample size was 80. Ear swab culture was done on blood agar, MacConkey agar, and chocolate agar. The culture plates were processed and identification of the isolates and antibiotic susceptibility were done as per standard methods. Samples with bacterial growth were 66 (82.5%), fungal growth were 10 (12.5%) and 4 (5%) samples had no growth. There were 82 isolates of bacteria and fungi from 80 patients. The predominant bacteria were Pseudomonas aeruginosa with 31 (37.80%) isolates followed by Staphylococcus aureus 25 (30.49%). All 31(100%) P. aeruginosa isolates were sensitive to colistin and polymixin B, while 30 (96.8%) isolates showed sensitivity to piperacillin-tazobactam, cefoperazone-sulbactam and aztreonam. Only 21 (67.7%) isolates were sensitive to gentamicin, 23 (74.2%) isolates were sensitive to ciprofloxacin, whereas 24 (77.4%) isolates were sensitive to levofloxacin. All 25 (100%) S. aureus isolates showed sensitivity to vancomycin, teicoplanin and linezolid whereas 23 (92%) isolates showed sensitivity to amikacin, doxycycline and clindamycin. Only one isolate (4%) was sensitive to ampicillin whereas 8 (32%) were sensitive to amoxicillin-clavulanic acid in vitro. P. aeruginosa and S. aureus are the most common aerobic bacterial pathogens in chronic suppurative otitis media. P. aeruginosa showed 100% sensitivity to Colistin and Polymixin B followed by Piperacillin-tazobactam (96.8%), Cefoperazone-sulbactam (96.8%) and Aztreonam (96.8%). S. aureus showed 100% sensitivity to Vancomycin, Teicoplanin and Linezolid followed by Amikacin, Doxycycline and Clindamycin (92% each). Culture and sensitivity should be done in chronic suppurative otitis media before initiating antibiotic therapy.