Abstract
Inadequate antibiotic treatment, misuse/improper choice of antibiotic and poor compliance of patients have resulted in changes in susceptibility to antibiotics of the causative organisms and also development of resistance to commonly used antibiotics. Thus, this study aimed to identify the bacteriological profile and determine antibiotic susceptibility pattern in CSOM patients. This 1-year cross-sectional study was conducted on 120 clinically diagnosed cases of CSOM attending ear, nose, and throat outpatient department. Ear discharges obtained were processed for bacterial culture (aerobic and anaerobic). Antimicrobial susceptibility testing was done by Kirby–Bauer disc diffusion method. Demographic and clinical characteristics of the patients were recorded. Of total 120 cases, pathogens were isolated from 116 cases. The commonest aerobic organism isolated was Pseudomonas aeruginosa (38.79%) followed by Staphylococcus aureus (32.75%). Staphylococcus aureus showed maximum sensitivity to erythromycin (71.05%), followed by cotrimoxazole (63.15%) and ampicillin (55.26%). Maximum resistance was observed for ciprofloxacin (78.9%), followed by amoxiclave (55.26%). Pseudomonas aeruginosa showed maximum sensitivity to piperacillin (91.11%) followed by gentamicin (71.11%), amikacin (71.11%), moderate sensitivity to ceftazidime (51.11%); however resistance to carbpenicillin (60%). Ciprofloxacin was the most prescribed topical agent showing an increase in resistance to common organisms of CSOM. Hence, it is mandatory to study each case of CSOM bacteriologically to formulate local antibiotic policy for appropriate use of antibiotics. This will certainly help in achieving a safe ear and to control the organisms developing resistance to prevalent antibiotics.
Keywords: Antimicrobial susceptibility pattern, Bacteriological profile, Chronic suppurative otitis media, Resistance, Sensitive
Introduction
Chronic suppurative otitis media (CSOM) is a chronic inflammation or persistent infection of the middle ear cleft—the Eustachian tube, middle ear, and mastoid air cells [1, 2]. It is the most commonly occurred infectious ear disease in children, as well as in young adults [3]. It is characterized by chronic, intermittent or persistent otorrhea or ear discharge for at least 2 weeks or more through a perforated tympanic membrane [4].
Although the ear infection affects all age-groups, owing to shorter Eustachian tube, more horizontal position and with a more flaccid cartilage and low immunity have made this bacterial infection more severe in children [5]. The most common causative organisms associated with CSOM include Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophillus influenzae. Other organisms include Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Proteus species [6]. However, type of organism involved in CSOM depends upon climatic conditions and geographical areas [7, 8]. Low socioeconomic status, poor living conditions, inadequate hygiene, malnutrition, overcrowding, inadequate antibiotic treatment, improper antibiotic choice, and misuse of antibiotics are the prime factors for the prevalence of CSOM in developing nations [9]. The poorer rural community has a significantly higher prevalence rate of CSOM than the urban community [10].
Changes in the microbial flora following the advent of sophisticated synthetic antibiotics increase the relevance of reappraisal of modern day flora of CSOM. Their in-vitro antibiotic susceptibility pattern is very important to the clinician to initiate an appropriate treatment and prevent the complications of CSOM [11, 12]. The altering flora of CSOM and emergence of strains resistant to the commonly employed antibiotics stimulated to conduct the study. Hence, the current study was undertaken to identify the bacteriological profile in CSOM patients and determine the antibiotic susceptibility pattern.
Materials and Methods
Study Design
A 1-year cross-sectional study was conducted at ear, nose, and throat (ENT) department. A total of 120 clinically diagnosed cases of CSOM attending ENT, OPD, and admitted in ENT wards were included for the study. Ethical clearance was obtained from Institutional Ethical Committee prior to the study. A written consent was also obtained from the patients before their participation in the study. The sample size was calculated using the formula, n = 4 pq/d2.
Sample Collection and Processing
Demographic data such as patient’s name, age, sex, and clinical characteristics of the patients were recorded standard proforma. Ear discharge was collected using a cotton swab under aseptic precautions after mopping out excess discharge from external auditory canal by an otorhinolaryngologist. Two out of four samples were transported in thioglycollate medium for anaerobic culture and two swabs transported in sterile containers for aerobic culture. Antimicrobial susceptibility profile of the bacterial isolates to the commonly used antibiotics was determined by Kirby–Bauer disc diffusion method, as per Clinical Laboratory Standard Institute (CLSI) guidelines.
Statistical Analysis
Data were pooled and analyzed using SPSS v20 software.
Results
Age of the patients ranged from 3 to 85 years with male predilection (55.83%). Maximum incidence was observed during second decade (29.16%) of life and the incidence decreased as the age advanced. The demographic including clinical characteristics of the study sample are shown in Table 1.
Table 1.
Demographic including clinical characteristics of the study population
| Variable | n (%) |
|---|---|
| Sex | |
| a. Male | 55.83 |
| b. Female | 44.17 |
| Age in years | |
| a. 1–10 | 19 (15.83) |
| b. 11–20 | 35 (29.16) |
| c. 21–30 | 19 (15.83) |
| d. 31–40 | 14 (11.67) |
| e. 41–50 | 17 (14.16) |
| f. 51–60 | 11 (9.16) |
| g. 61–70 | 3 (2.5) |
| h. 71–80 | 1 (0.8) |
| i. > 80 | 1 (0.8) |
| Socioeconomic status | |
| a. Lower class | 48.3 |
| b. Middle class | 33.3 |
| c. Upper class | 18.3 |
| Infection | |
| a. Unilateral ear | 27 (22.5) |
| b. Bilateral ear | 93 (77.5) |
| Clinical type of CSOM | |
| a. Tubotympanic | 104 (86.67) |
| b. Atticoantral | 16 (13.33) |
Out of 120 cases, 116 were culture positive and the total number of bacterial isolates was 116. The bacteriological profile in this study showed aerobic growth in 105 (90.5%) cases and anaerobic growth in 11 (9.5%) cases. All the cases had monomicrobial growth. The most common aerobic organism isolated was Pseudomonas aeruginosa (38.79%) and the most common anaerobic organism isolated was Prevotella intermedia (4.3%). Also, out of 116 isolates identified, 60.49% cases were of gram-negative organisms and 39.51% cases were of gram-positive organisms (Table 2).
Table 2.
Distribution of aerobic and anaerobic isolates
| Organisms isolated | No. of isolates, n (%) |
|---|---|
| Aerobic organisms | |
| Pseudomonas aeruginosa | 45 (38.79) |
| Staphylococcus aureus | 38 (32.75) |
| Methicillin resistant staphylococcus aureus | 6 (5.17) |
| Citrobacter freundii | 4 (3.5) |
| Proteus mirabilis | 3 (2.58) |
| Escherichia coli | 3 (2.58) |
| Klebsiella pneumoniae | 2 (1.72) |
| Acinetobacter | 1 (0.8) |
| Citrobacter koseri | 1 (0.8) |
| Streptococcus pneumoniae | 1 (0.8) |
| Coagulase negative staphylococcus | 1 (0.8) |
| Anaerobic organisms | |
| Prevotella intermedia | 5 (4.3) |
| Bacteroides fragilis | 4 (3.5) |
| Porphyromonas | 2 (1.7) |
The sensitivity and resistance of all gram-positive and gram-negative organisms to different antibiotics is summarized in Table 3. Among the gram-positive organisms, Staphylococcus aureus showed maximum sensitivity to erythromycin (71.05%), followed by cotrimoxazole (63.15%), and ampicillin (55.26%). Maximum resistance was observed for ciprofloxacin (78.9%), followed by amoxiclave (55.26%). Among gram-negative organisms, Pseudomonas aeruginosa showed maximum sensitivity to piperacillin (91.11%), followed by gentamicin (71.11%), amikacin (71.11%), moderate sensitivity to ceftazidime (51.11%), and resistant to carbpenicillin (60%; Table 3).
Table 3.
Antimicrobial sensitivity and resistance pattern of bacteria isolated from chronic suppurative media patients
| Organism | S/R n (%) | AMP, n (%) | COT, n (%) | CIP, n (%) | E, n (%) | PIP, n (%) | GEN, n (%) | AK, n (%) | LEV, n (%) | CF, n (%) | CBP, n (%) | AMC, n (%) | CFZ, n (%) | KM, n (%) | VM, n (%) | CL, n (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PA | S | – | – | – | – | 41 (91.1) | 32 (71.11) | 32 (71.11) | – | 23 (51.11) | 18 (40) | – | – | – | – | – |
| R | – | – | – | – | 4 (8.89) | 13 (28.89) | 13 (28.89) | – | 22 (48.89) | 27 (60) | – | – | – | – | – | |
| SA | S | 21 (55.26) | 24 (63.15) | 8 (21.1) | 27 (71.05) | – | – | – | – | – | – | 17 (44.74) | – | – | – | – |
| R | 17 (44.74) | 14 (36.85) | 30 (78.9) | 11 (28.95) | – | – | – | – | – | – | 21 (55.26) | – | – | – | – | |
| MRSA | S | 3 (50) | 4 (66.67) | 1 (16.7) | 5 (83.3) | – | – | – | – | – | – | 3 (50) | – | – | – | – |
| R | 3 (50) | 2 (33.33) | 5 (83.3) | 1 (16.7) | – | – | – | – | – | – | 3 (50) | – | – | – | – | |
| CF | S | 1 (25) | 4 (100) | 4 (100) | – | 4 (100) | 3 (75) | – | 4 (100) | – | – | – | ||||
| R | 3 (75) | 0 | 0 | – | 0 | 1 (25) | – | 0 | – | – | – | |||||
| PM | S | – | – | – | – | 3 (100) | 2 (66.6) | 2 (66.6) | – | 1 (33.4) | 2 (66.6) | – | – | – | – | – |
| R | – | – | – | – | 0.00 | 1 (33.4) | 1 (33.4) | – | 2 (66.6) | 1 (33.4) | – | – | – | – | – | |
| EC | S | 1 (33.3) | 1 (33.3) | 1 (33.3) | – | 1 (33.3) | 3 (100) | – | – | – | – | 0.00 | – | – | – | |
| R | 2 (66.7) | 2 (66.7) | 2 (66.7) | – | 2 (66.7) | 0 | – | – | – | – | 3 (100) | – | – | – | ||
| KP | S | 1 (50) | 1 (50) | 1 (50) | – | – | – | 0 | – | 1 (50) | 0 | – | – | – | ||
| R | 1 (50) | 1 (50) | 1 (50) | – | – | – | 2 (100) | – | 1 (50) | 2 (100) | – | – | – | |||
| A | S | – | – | – | – | 1 (100) | 1 (100) | 1 (100) | – | 0 | 1 (100) | – | – | – | – | – |
| R | – | – | – | – | 0 | 0 | 0 | – | 1 (100) | 0 | – | – | – | – | – | |
| CK | S | 1 (100) | – | – | – | 1 (100) | 1 (100) | – | – | – | 1 (100) | – | 0 | – | – | – |
| R | 0 | – | – | – | 0 | 0 | – | 0 | – | 1 (100) | – | – | – | |||
| SP | S | – | – | – | 0 | 1 (100) | 0 | 1 (100) | 0 | – | – | – | – | |||
| R | – | – | – | 1 (100) | – | 0 | – | 1 (100) | 0 | 1 (100) | – | – | – | – | ||
| CONS | S | 1 (100) | 0 | 0 | 0 | – | – | – | – | – | – | 0 | – | – | – | – |
| R | 0 | 1 (100) | 1 (100) | 1 (100) | – | – | – | – | – | – | 1 (100) | – | – | – | – | |
| PI | S | – | – | – | – | – | – | – | – | – | – | – | – | 4 (80) | 1 (20) | 5 (100) |
| R | – | – | – | – | – | – | – | – | – | – | – | – | 1 (20) | 4 (80) | 0 | |
| BF | S | – | – | – | – | – | – | – | – | – | – | – | – | 2 (50) | 1 (25) | 2 (50) |
| R | – | – | – | – | – | – | – | – | – | – | – | – | 2 (50) | 3 (75) | 2 (50) | |
| PPM | S | – | – | – | – | – | – | – | – | – | – | – | – | 2 (100) | 0 | 0 |
| R | – | – | – | – | – | – | – | – | – | – | – | – | 0 | 2 (100) | 2 (100) |
S sensitive; R resistant
PA Pseudomonas aeuroginosa; SA Staphylococcus aureus; MRSA Methicillin resistant Staphylococcus aureus; CF Citrobacter freundii; PM Proteus mirabilis; EC Escherichia coli; KP Klebsiella pneumonia; A Acinetobacter; CK Citrobacter koseri; SP Streptococcus pneumonia; CONS Coagulase negative staphylococcus; PI Prevotella intermedia; BF: Bacteroides fragilis; PPM Porphyromonas
AMP ampicillin; COT cotrimoxazole; CIP ciprofloxacin; E erythromycin; PIP piperacillin; GEN gentamicin; AK amikacin; LEV levofloxacin; CF ceftriaxone; CBP carbpenicillin; AMC amoxiclave; CFZ ceftazidime; KM kanamycin; VM vancomycin; CL colistin
Discussion
CSOM and complications associated with this are the most common conditions seen by the otologist, pediatrician, and the general practitioners [13]. It is a persistent disease with great risk of irreversible complications. Early bacteriological diagnoses of all the cases will assume accurate and appropriate effective therapy [14].
In this study most of the patients were in the age-group of 11–20 years. These findings are in correlation with that of Kumar et al. [15], Parween et al., and Deb et al. [16]. Studies conducted by Poorey et al. [13] and Saraswati et al. [17] showed that maximum number of patients were below 20 years of age. Whereas, Vishwanath et al. [18] and Loy et al. [19] had reported maximum number of patients in third decade. Male predominance was slightly high in this study. This finding was similar to the studies conducted by Deb et al. [16], Sharma et al. [20], Hiremath et al. [21]. The unilateral infection (77.5%) was more common compared to bilateral infection (22.5%). This findings were similar to the results of study conducted by Kumar et al. [15] and Sharma et al. [22]. CSOM was a disease among the lower (48.3%) and middle (33.3%) class of the individuals in the present study. Similar results were observed in the studies of Gulati et al. [23] and Hiremath et al. [21].
In the present study, 96.67% of samples were positive and 3.33% were negative for the culture. The positivity of culture growth was similar to the results of the studies conducted by Saraswati et al. [17] (83%), Vishwanath et al. [18] (88.3%), and Hiremath et al. [21] (84%). Among 116 isolates, the bacteriological profile in this study showed aerobic growth in 105 (90.5%) cases and anaerobic growth in 11 (9.5%) cases. A study by Vishwanath et al. [18] showed 74.8% of aerobic growth and 15.6% of anaerobic growth. In a similar study by Loy et al.’s [19] 66.6% of samples showed aerobic growth and 6% showed anaerobic growth. The gram-negative organisms (60.49%) outnumbered the gram-positive organisms (39.51%) in this study [24].
The occurrence of Pseudomonas aeruginosa as the predominant organism in this study could be attributed to numerous factors. Pollock [25] stated that Pseudomonas aeruginosa survives competition with other pathogens due to its minimum nutritional requirements, its relative resistance to antibiotics, and its armamentarium of antibacterial products—pyocyanin and bacteriocin. Apart from these reasons, it uses the pili to attach to the necrotic or diseased epithelium of the middle ear. Once attached, the organism produces enzymes such as proteases and lipopolysaccharides to elude from normal defense mechanism of the body required for fighting infections. In addition, the organism acts as an opportunistic pathogen, which flourishes in the external auditory canal and causes suppurative otitis media. Similarly, studies conducted by Vishwanath et al. [18] (32.2%), Kumar et al. [15] (46%), Deb et al. [16] (79%) and Poorey et al. [13] (35.2%)7 also reported Pseudomonas aeruginosa as the predominant organism.
The second most common organism isolated was Staphylococcus aureus (32.75%), which was comparable to the studies conducted by Deb et al. (20%) [16] and Kumar et al. (33%) [15]. The high incidence of resistant strains in external auditory canal as well as upper respiratory tract have increased the incidence of Staphylococcus aureus in the middle ear. In contrast, a study conducted by Prakash et al. [26] reported staphylococcus aureus (41.25%) as the predominant isolate.
Methicillin-resistant staphylococcus aureus, Proteus mirabilis, Citrobacter freundii, Klebsiella pneumonia, Escherichia coli, Streptococcus pneumoniae, Acinetobacter, Enterococcus, Citrobacter koseri, and Coagulase negative staphylococcus were the other organisms isolated in patients with CSOM. Similar organisms have been found to be associated with CSOM in studies conducted by Kumar et al. [15], Sharma et al. [20], Vishwanath et al. [18], and Poorey et al. [13].
With regard to antibiotic susceptibility for organisms, Staphylococcus aureus showed maximum sensitivity to erythromycin, followed by cotrimoxazole, and moderate sensitivity to ampicillin. Whereas, maximum resistance was seen for ciprofloxacin, followed by amoxiclave. Similarly, in a study conducted by Vishwanath et al. [18], staphylococcus aureus showed maximum sensitivity to erythromycin (75%), cotrimoxazole (95%), moderate sensitivity to ampicillin (55%), and ciprofloxacin (45%). A study by Deb et al. [16] showed 50% resistance to ciprofloxacin. In contrast, In a study by Sharma et al. [22], Staphylococcus aureus showed sensitivity to ciprofloxacin (81%) and erythromycin (75%).
Ciprofloxacin is considered as an potential drug in the management of CSOM, as it is economical, less ototoxic, and most widely available in the form of topical preparations [27]. Although, studies have shown sensitivity to the organisms; however, recent studies have shown increase in resistance of ciprofloxacin to commonly causing organisms of CSOM [28], which coincided with our study.
Antibiotic susceptibility pattern for Pseudomonas aeruginosa was determined for gentamicin, amikacin, ceftazidime, piperacillin, and carbpenicillin. Pseudomonas aeruginosa showed maximum sensitivity to piperacillin (91.11%), followed by gentamicin (71.11%), amikacin (71.11%), moderate sensitivity to ceftazidime (51.11%), and resistance to carbpenicillin (60%). According to study by Vishwanath et al. [18], Pseudomonas aeruginosa showed maximum sensitivity to piperacillin (97.3%), followed by gentamicin (73%), amikacin (78.4%), ceftazidime (91.2%), and resistance to netilmycin (2.7%). which correlates with our study. According to Sharma et al. [20], Pseudomonas aeruginosa showed sensitive to piperacillin (25%), gentamicin (30%). which differs from our study. Gentamicin and amikacin were found to be the most effective aminoglycoside; however, the risk of ototoxicity by using aminoglycoside preparations remains a subject of discussion and prevents their routine use.
The Prevotella intermedia showed maximum sensitivity to colistin (100%), followed by kanamycin (80%), and showed resistance to vancomycin (80%). Bacteroides fragilis showed sensitivity to colistin (50%), kanamycin (50%), and resistance to vancomycin (75%). Porphyromonas showed sensitivity to kanamycin (100%), and resistance (100%) to vancomycin, and colistin. Although anaerobes play a pathogenic role in CSOM, the large variability in their isolation rates among different studies may be due to differences in sampling time and difference in prior use of antibiotics during the study course.
Conclusion
Overall, gram-positive aerobic organisms showed sensitivity to erythromycin, cotrimoxazole, and ampicillin, whereas maximum resistance was seen for ciprofloxacin followed by amoxiclave. Gram-negative aerobic organisms showed sensitivity to piperacillin, gentamicin, amikacin, ceftazidime, and resistance to carbpenicillin. Anaerobic organisms showed sensitivity to colistin, kanamycin and showed resistance to vancomycin. Ciprofloxacin, the most prescribed topical agent, showed an increase in resistance to common organisms of CSOM. In the present era, the emergence of antibiotic resistance is becoming more common due to human negligence of stopping antibiotics before completion of course as symptoms subside and allow partially resistant microbes to flourish. Such practice should be discouraged strongly and patients should be educated to avoid the same. Therefore, it becomes crucial to study each case of CSOM bacteriologically to formulate local antibiotic policy for appropriate use of antibiotics. This will certainly help in achieving a safe ear and to control the organisms developing resistance to prevalent antibiotics.
Contributor Information
Basavaraj Hiremath, Email: h_basavaraj@yahoo.com.
R. S. Mudhol, Email: rsmudhol@yahoo.co.in
Manjula A. Vagrali, Email: drmanjulavagrali@yahoo.com
References
- 1.Indudharan R, Haq JA, Aiyar S. Antibiotics in chronic suppurative otitis media: a bacteriologic study. Ann Otol Rhinol Laryngol. 1999;108:440–445. doi: 10.1177/000348949910800504. [DOI] [PubMed] [Google Scholar]
- 2.Acuin J. Chronic suppurative otitis media. BMJ Clin Evid. 2007;2007:0507. [PMC free article] [PubMed] [Google Scholar]
- 3.Adhikari P, Joshi S, Baral D, Kharel B. Chronic suppurative otitis media in urban private school children of Nepal. Braz J Otorhinolaryngol. 2009;75:669–672. doi: 10.1016/S1808-8694(15)30516-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Varshney S, Nangia A, Bist S, Singh R, Gupta N, Bhagat S. Ossicular chain status in chronic suppurative otitis media in adults. Indian J Otolaryngol Head Neck Surg. 2010;62:421–426. doi: 10.1007/s12070-010-0116-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Wasihun AG, Zemene Y. Bacterial profile and antimicrobial susceptibility patterns of otitis media in Ayder Teaching and Referral Hospital, Mekelle University, Northern Ethiopia. Springerplus. 2015;4:701. doi: 10.1186/s40064-015-1471-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Sena RB, Gandham P. Antibiotic susceptibility pattern among CSOM patients attending AIMSR. Natl J Integr Res Med. 2016;7:108–111. [Google Scholar]
- 7.Okesola A, Fasina O. Trends in the resistance pattern of bacterial pathogens of otitis media in Ibadan, Nigeria. Afr J Clin Exp Microbiol. 2012;13:416–450. [Google Scholar]
- 8.Brook I, Frazier EH. Microbial dynamics of persistent purulent otitis media in children. J Pediatr. 1996;128:237–240. doi: 10.1016/S0022-3476(96)70397-9. [DOI] [PubMed] [Google Scholar]
- 9.Yogeesha B, Venkatesha B. Study of bacteriological profile and antibiotic sensitivity pattern in chronic otitis media-mucosal type in tertiary care hospital. IOSR J Dent Med Sci. 2016;1:82–86. [Google Scholar]
- 10.Smith JA, Danner CJ. Complications of chronic otitis media and cholesteatoma. Otolaryngol Clin North Am. 2006;39:1237–1255. doi: 10.1016/j.otc.2006.09.001. [DOI] [PubMed] [Google Scholar]
- 11.Mane PM, Basawraju A. Clinical significance of microbial flora in middle ear infections and its implications. Trop J Med Res. 2016;19:128. doi: 10.4103/1119-0388.185437. [DOI] [Google Scholar]
- 12.Kumar D, Agarwal M, Prakash P. Bacteriological profile of chronic suppurative otitis media in patients at a tertiary level hospital. Eastern J Med Sci. 2016;1:5–7. [Google Scholar]
- 13.Poorey V, Lyer A. Study of bacterial flora in CSOM and its clinical significance. Indian J Otolaryngol Head Neck Surg. 2002;54:91–95. doi: 10.1007/BF02968724. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Mohammad AH. Chronic suppurative otitis media: microbial and antimicrobial findings. Int J Adv Res. 2016;4:1315–1320. doi: 10.21474/IJAR01/707. [DOI] [Google Scholar]
- 15.Kumar R, Srivastava P, Sharma M, Rishi S, Nirwan S, Hemwaniand K. Isolation and antimicrobial sensitivity profile of bacterial agents in chronic suppurative otitis media patients at NIMS Hospital. Int J Pharm Biol Sci. 2013;3:265–269. [Google Scholar]
- 16.Deb T, Ray D. A study of the bacteriological profile of chronic suppurative otitis media in agartala. Indian J Otolaryngol Head Neck Surg. 2012;64:326–329. doi: 10.1007/s12070-011-0323-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Saraswati JR, Venkatesh R, Jeya M. Study of aerobic bacterial and fungal etiology of chronic suppurative otitis media in tertiary care hospital in out skirts of Chennai, India. Int J Health Sci Res. 2013;1:199–201. [Google Scholar]
- 18.Vishwanath S, Mukhopadhyay C, Prakash R, Pillai S, Pujary K, Pujary P. Chronic suppurative otitis media: optimizing initial antibiotic therapy in a tertiary care setup. Indian J Otolaryngol Head Neck Surg. 2012;64:285–289. doi: 10.1007/s12070-011-0287-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Loy A, Tan A, Lu P. Microbiology of chronic suppurative otitis media in Singapore. Singapore Med J. 2002;43:296–299. [PubMed] [Google Scholar]
- 20.Sharma K, Aggarwal A, Khurana PMS. Comparison of bacteriology in bilaterally discharging ears in chronic suppurative otitis media. Indian J Otolaryngol Head Neck Surg. 2010;62:153–157. doi: 10.1007/s12070-010-0021-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Hiremath S, Kanta R, Yeshwanathrao M, Vasantha Kumar C. Aerobic bacterial isolates of CSOM and their antibiotic sensitivity pattern. Indian Pract. 2001;54:486–489. [Google Scholar]
- 22.Sharma V, Kaur G. Microbiology and antimicrobial susceptibility pattern of cases of chronic suppurative otitis media in a tertiary care teaching hospital. Int J Bioassays. 2014;3:3033–3035. [Google Scholar]
- 23.Gulati SK. Investigative profile in patients of chronic suppurative otitis media. Indian J Otol. 1997;3:59–62. [Google Scholar]
- 24.Seid A, Deribe F, Ali K, Kibru G. Bacterial otitis media in all age group of patients seen at Dessie referral hospital, North East Ethiopia. Egyptian J Ear, Nose, Throat Allied Sci. 2013;14:73–78. doi: 10.1016/j.ejenta.2013.02.005. [DOI] [Google Scholar]
- 25.Pollock M. Special role pseudomonas aeruginosa in CSOM: workshop on CSOM etiology and management. An Otorhinolaryngol. 1996;17:6. [Google Scholar]
- 26.Prakash SK. Aerobic bacteriology of chronic suppurative otitis media (CSOM) in a tertiary care hospital in North India. J Med Sci clin Res. 2014;2:395–398. [Google Scholar]
- 27.Samarei R. Comparison of local and systemic ciprofloxacin ototoxicity in the treatment of chronic media otitis. Glob J Health Sci. 2014;6:144. doi: 10.5539/gjhs.v6n7p144. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Ali SQ, Zehra A, Naqvi BS, Shah S, Bushra R. Resistance pattern of ciprofloxacin against different pathogens. Oman Med J. 2010;25:294–298. doi: 10.5001/omj.2010.85. [DOI] [PMC free article] [PubMed] [Google Scholar]