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Year : 2022  |  Volume : 15  |  Issue : 1  |  Page : 27-31  

A Study on bacteriological profile and the antibiotic susceptibility pattern in cases of chronic suppurative otitis media in Haroti region

1 Department of Microbiology, Government Medical College, Kota, Rajasthan, India
2 Department of Pathology, Government Medical College, Kota, Rajasthan, India
3 Department of Pathology, Government Medical College, Baripada, Odisha, India

Date of Submission21-May-2020
Date of Decision08-Feb-2021
Date of Acceptance26-Feb-2021
Date of Web Publication26-Feb-2021

Correspondence Address:
Lakshmi Agarwal
Department of Pathology, Government Medical College, Kota, Rajasthan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mjdrdypu.mjdrdypu_270_20

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Introduction: Chronic suppurative otitis media (CSOM) is one of the common hearing problems which can cause many complications if not treated properly. Hence, the study aims to identify the bacterial isolates causing CSOM and to study their antimicrobial susceptibility pattern. Materials and Methods: The study was carried out in a tertiary care hospital in Kota from May 2019 to January 2020. Three hundred and seventy patients of CSOM with discharge attending the ENT outpatient department were included in the study. Swabs were taken and sent immediately to the microbiology laboratory and processed. Bacterial isolates were identified using standard methods and antibiotic susceptibility testing was done. Results: Pseudomonas was the most predominant bacteria isolated followed by Staphylococcus aureus, Coagulase-negative Staphylococcus, Enterobacter spp., Proteus spp., Streptococcus pneumonia, Klebsiella spp., Enterococcus and Acinetobacter spp. Conclusions: The present study helped in knowing the bacteriological profile of the cases of CSOM. Empirical treatment may not be successful in all cases because of the emergence of resistant organisms. Hence, it is advisable to do an antibiogram before starting the treatment.

Keywords: Antibiotic susceptibility, bacterial isolates, chronic suppurative otitis media, complications

How to cite this article:
Garg A, Agarwal L, Gupta M, Mathur R. A Study on bacteriological profile and the antibiotic susceptibility pattern in cases of chronic suppurative otitis media in Haroti region. Med J DY Patil Vidyapeeth 2022;15:27-31

How to cite this URL:
Garg A, Agarwal L, Gupta M, Mathur R. A Study on bacteriological profile and the antibiotic susceptibility pattern in cases of chronic suppurative otitis media in Haroti region. Med J DY Patil Vidyapeeth [serial online] 2022 [cited 2022 Aug 20];15:27-31. Available from: https://www.mjdrdypv.org/text.asp?2022/15/1/27/321290

  Introduction Top

Chronic suppurative otitis media (CSOM) is a chronic inflammation of the middle ear and mastoid cavity, which presents with recurrent ear discharge through a tympanic membrane perforation due to various causes. It is one of the important causes for hearing loss and single major cause for conductive deafness (66.3%).[1] It is also responsible for 1.5% of speech disorders.[2]

The disease usually occurs after upper respiratory viral infections followed by the invasion of pyogenic organisms.[3] It is famous for its recurrence and persistent infection despite treatment. CSOM can cause severe adverse effects. It can damage ossicles, facial nerve, and cochlea resulting in permanent hearing loss. It can lead to intracranial and extracranial complications which can be life-threatening.

The incidence of CSOM is increasing in the developing countries because of the poor hygienic practices, overcrowding, lack of health education, and recurrent upper respiratory tract infections. It is a common problem for all age groups.[4] However, the infection is more severe in children causing conductive hearing loss which may lead to delayed development of speech and language in children. This is due to the shorter  Eustachian tube More Details, more horizontal position, flaccid cartilage, and low immunity.[4],[5]

Normal flora of the skin such as Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumonia, and  Escherichia More Details coli that can easily enter through perforated ear has been reported as the main agents of otitis media. The anaerobes such as Bacteroides, Peptostreptococcus, Proprionibacterium, and fungal pathogen such as Aspergillus and Candida also cause ear infection. The etiology and prevalence of ear infection differ with geographical and climate conditions and with different antibiotic sensitivity patterns.

The complications of CSOM have been reduced recently by early treatment and diagnosis. However, the irrational use of antibiotics has led to the emergence of resistant organisms to the commonly used drugs. This led to the recurrence and persistence of low-grade infections, which further increases the morbidity of the patient.

Hence this study is carried out to know the bacterial etiology of CSOM and their antibiotic susceptibility pattern. This knowledge is very important for appropriate management of the cases and to prevent or minimize the occurrence of complications. It will also help in preventing the emergence of resistant strains in the community. Hence, knowing the antibiotic sensitivity pattern before prescribing the drugs becomes very essential as the pattern of sensitivity and the organisms causing CSOM keeps changing.

  Materials and Methods Top

This study was carried out in a tertiary care hospital from May 2019 to January 2020. The approval of the Ethical Committee was obtained before the study [Letter of Director dated 01 April 2019]. A total of 370 patients with symptoms of CSOM were included in the present study. Ear discharge was collected under strict aseptic precautions using two sterile cotton swabs and processed immediately in the microbiology laboratory. The first swab was used for direct Gram stain and the second swab was cultured on blood agar, MacConkey agar, and Chocolate agar plates and incubated at 370°C for 24–48 h. The isolates grown were identified by their cultural characteristics, morphology, and biochemical reactions. Antibiotic susceptibility testing of the organisms diagnosed was done by Kirby–Bauer method in Mueller –Hinton agar. The plates were read after overnight incubation at 370°C by measuring the zone of inhibition around the antibiotic discs as per CLSI (Clinical Laboratory Standards Institute) guidelines.

Culture for anaerobic organisms was not performed in this present study.

Inclusion criteria

  1. Patients presenting with complaints of intermittent or persistent ear discharge in one or both ears for at least 3 weeks
  2. Patients of all age and both sexes
  3. Patients who have not taken any antibiotic treatment either systemically or locally for the past 1 week.

Exclusion criteria

  1. Patients receiving antibiotics at the time of presentation or previous 1 week
  2. Discharge with intact tympanic membrane (Otitis externa).

  Results Top

Three hundred and seventy patients were included in the study comprising 166 males and 204 females [Table 1].
Table 1: Sex distribution of cases

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Among the 370 samples, 353 (95.40%) were culture positive. Seventeen samples were culture negative. 13.51% of the samples showed mixed growth.

The most common organism isolated in this study was Pseudomonas species (28.37%) followed by S. aureus (12.43%), Enterobacter spp. (4.59%) Proteus spp. (4.32%), Klebsiella spp. (1.62%), and Coagulase Negative Staphylococcus (7.56%) were the other organisms isolated [Table 2].
Table 2: Organisms isolated from culture

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Among the S. aureus, 39.13% were methicillin-resistant S. aureus (MRSA) and 60.87% were methicillin-sensitive S. aureus. The organism was 100% sensitive to amikacin, chloramphenicol, vancomycin, and linezolid [Table 3].
Table 3: Antibiotic sensitivity pattern for Staphylococcus

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Pseudomonas spp. are highly sensitive to imipenem (93.4%), meropenem (93.4%), and doripenem (98.1%). It showed 92.39% susceptibility to amikacin, 90.48% susceptibility to gentamicin, and 80.96% to fluoroquinolones [Table 4].
Table 4: Antibiotic sensitivity pattern of Gram-negative bacilli

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Rest other Gram-negative bacteria were 100% susceptible to imipenem, meropenem, doripenem, piperacillin, tazobactam, and cefoperazone-sulbactum and 93%–100% susceptible to amikacin, gentamicin and 80%–100% susceptible to fluoroquinolones.

  Discussion Top

Suppurative otitis media is a common disease with approximately 5% global incidence.[6] CSOM is one of the common ear infections which is more commonly reported from the rural and lower socioeconomic status population.[7],[8] It is a chronic infection of middle ear having its onset in childhood and causing considerable morbidity into adulthood. There is recurrent ear discharge through a persistent perforated eardrum which can later lead to deafness. This recurrence is characterized by osteogenesis, bony erosions, and osteitis in the temporal bone and ossicles.[9] Bacteria are believed to gain access to the middle ear cleft either from the external auditory canal through the perforation or from the nasopharynx through the eustachian tube or both. Regardless of the entry mechanism, biofilm formation has been suggested to explain the recalcitrant nature of CSOM.[10]

Various risk factors have been quoted in the literature for the development of CSOM including frequent upper respiratory tract infections, nasal disease, inadequate antibiotic treatment, poor living conditions with poor nutrition, and hygiene. These risk factors weaken the immunological defenses leading to early infection.[11]

Poorly treated or untreated CSOM can lead to many complications such as mastoiditis, meningitis, and brain abscess. Hence, the diagnosis of the causative organism is necessary for proper management of CSOM cases.

In CSOM, the causative bacteria may be aerobic (e.g., Pseudomonas aeruginosa, E. coli, S. aureus, Streptococcus pyogenes, Proteus mirabilis, Klebsiella species) or anaerobic (e.g., Bacteroides, Peptostreptococcus, Propionibacterium). The bacteria are infrequently found in the skin of the external auditory canal and may proliferate in the presence of trauma, inflammation or high humidity. These bacteria may gain entry into the middle ear through a chronic perforation. Among these bacteria, P. aeruginosa is known to cause deep-seated and progressive destruction of the middle ear and mastoid structures through its toxins and enzymes.[12]

In our study, 45% were males and 55% were females. Thus, females were affected more in our study which is the same as Loy et al.,[13] but differs from Ahmed et al.[14] His study showed 57.3% male and 42.7% female. As this study involved a random selection of cases, the prevalence of male patients over female patients may be only an incidental finding.

Monomicrobial growth was seen in 81.89% of cases, which is similar to the study done by Agarwal et al.[15] This observation was also supported by various other studies.[16],[17],[18],[19],[20],[21]

In the present study, multiple bacteria were isolated from 50 samples (13.5%).

Seventeen of the samples (4.5%) showed no growth. This is in accordance with Vijaya et al.[22] who found 5.28% sterile samples whereas Fatma et al.[23] (16.9%) and Chakraborty et al.[24] (12.6%) found a higher percentage of culture-negative samples in their studies. Gram-negative bacteria (40.27%) were the dominant isolates compared to Gram-positive bacteria (23.78%).

Among the aerobic bacterial isolates, P. aeruginosa was predominant, followed by S. aureus, Coagulase-negative Staphylococcus, Enterobacter spp, Proteus spp., Streptococcus pneumonia, Klebsiella spp., Enterococcus, and Acinetobacter spp.

Aspergillus spp. was the predominant fungus followed by Candida spp.

S. aureus and Pseudomonas spp. together account for the majority (40.81%) of cases. Shyamala et al.,[16] Iseh and Adegbite et al., Aslam et al.[25],[26],[27] also found the similar findings.

The results showed that overall P. aeruginosa was the most common aerobic isolate followed by S. aureus which is in agreement with the reports of some other investigators in different parts of the worlds.[28],[29],[30]

Among the Gram-negative pathogens, next to Pseudomonas is Enterobacter (4.59%) and Proteus (4.32%) followed by Klebsiella pneumoniae (1.62%).

Staphylococcus was isolated in 12.43%, MRSA in 39.13%, CONS (Coagulase negative S. aureus) in 7.56%, S. pneumoniae in 2.43% and enterococcus in 1.35% of cases. Coagulase-negative Staphylococcus usually considered as the commensal organism of the skin, but rarely can become an opportunistic pathogen.

Out of 370 culture positives, 66 were fungal isolates. Among the fungal isolates, Aspergillus spp. was isolated in 11.89% followed by Candida spp. in 5.94% cases.

The variation in climatic and geographic could be the possible reasons for the difference in the distribution of the bacteria.

Antibiotic susceptibility pattern was tested for all the bacterial isolated organisms.

The antibiotics susceptibility pattern of P. aeruginosa showed that the isolates were highly sensitive to doripenem, meropenem, imipenem, tobramycin, amikacin, piperacillin-tazobactum followed by aztreonam, gentamicin, cefipime as shown in [Table 4]. They were a little less sensitive to fluoroquinolones and least sensitive to ceftazidime in our study.

Staphylococcus isolates were 100% sensitive to vancomycin, linezolid, and amikacin. They were highly sensitive to doxycycline, chloramphenicol followed by gentamicin. They showed less sensitivity against commonly used antibiotics such as cefoxitin, erythromycin, ciprofloxacin, clindamycin, and cotrimoxazole. They were least sensitive to fluoroquinolones as shown in [Table 3].

Gram-negative isolates other than Pseudomonas showed 100% sensitivity to carbapenems, piperacillin-tazobactam and cefoperazone-sulbactam. They were highly sensitive to amikacin, gentamicin followed by moderately sensitive to ciprofloxacin, levofloxacin, co-trimoxazole, amoxiclav, ampi-sulbactam, and doxycycline. They were less sensitive to third-generation cephalosporins as shown in [Table 4].

In this study, most of the organisms were found to be resistant to regularly used cell wall inhibitors like penicillin group of drugs and cephalosporins.

The clinician should be aware of the fact that the antibiotic susceptibility pattern of the CSOM causing organisms keeps changing. This variation is even worsened by misuse of antibiotics, which tend to create multidrug resistance among the organisms, thereby making the management of CSOM more difficult.

Hence for rational antibiotic use and success of treatment of CSOM, appropriate knowledge of antibacterial susceptibility of causative microorganisms is imperative.

  Conclusions Top

A continuous and periodic evaluation of microbiological pattern and their antibiotic sensitivity pattern in the local area helps build an antibiotic policy, prescribe empirical antibiotics for successful treatment of otitis media, and minimizing its complications and emergence of resistant strains as well as in long term, reduces the burden of the infection and cost of treatment on the patient.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Shenoi PM. Management of chronic suppurative otitis media. In: Scott Brown's Textbook of Otorhinolaryngology. 5th ed., Vol. 3. Oxford: Butterworth, Heinemann; 1988. p. 215.  Back to cited text no. 1
Rama Rao MV, Jayakar PA. Bacteriological study of chronic suppurative otitis media. Indian J Med Assoc 1980;75:30-3.  Back to cited text no. 2
Fliss DM, Shoham I, Leiberman A, Dagan R. Chronic suppurative otitis media without cholesteatoma in children in southern Israel: Incidence and risk factors. Pediatr Infect Dis J 1991;10:895-9.  Back to cited text no. 3
Bluestone CD, Klein JO, editors. Microbiology. In: Otitis Media in Infants and Children. 3rd ed. Philadelphia: P A W B. Saunders; 2002. p. 79-1014.  Back to cited text no. 4
Weiner R, Collison PJ. Middle Ear pathogens in Otitis prone children. S D J Med 2003;56:103-7.  Back to cited text no. 5
Monasta L, Ronfani L, Marchetti F, Montico M, Vecchi Brumatti L, Bavcar A, et al. Burden of disease caused by otitis media: Systematic review and global estimates. PLoS One 2012;7:e36226.  Back to cited text no. 6
Anifasi WB, Tumushime-Buturo CG. Bacteriology and drug sensitivity of chronic suppurative otitis media at a central hospital in Zimbabwe. Cent Afr J Med 1989;35:481-3.  Back to cited text no. 7
Fairbanks D. Pocket Guide to antimicrobial therapy in otolaryngology-head and neck surgery. In: Alexendria VA, editor. The American Academy of Otolaryngology-Head and Neck Surgery Foundation. 8th ed. St Louis: Mosby; 1996. p. 1-91.  Back to cited text no. 8
Meyerhoff W. Pathology of chronic suppurative otitis media. Ann Otol Rhinol Laryngol Head Neck Surg 1988;97 Suppl 130:21-4.  Back to cited text no. 9
Madana J, Yolmo D, Kalaiarasi R, Gopalakrishnan S, Sujatha S. Microbiological profile with antibiotic sensitivity pattern of cholesteatomatous chronic suppurative otitis media among children. Int J Pediatr Otorhinolaryngol 2011;75:1104-8.  Back to cited text no. 10
Berman S. Otitis media in children. N Engl J Med 1995;332:1560-5.  Back to cited text no. 11
Acuin J. Chronic Suppurative Otitis Media- Burden of Illness and Management Options. Geneva: World Health Organisation; 2004. Available from: http://www.who.int/pbd/publications/Chronicsuppurativeotitis_media.pdf. [Last accessed on 12 Nov 20].  Back to cited text no. 12
Loy AH, Tan AL, Lu PK. Microbiology of chronic suppurative otitis media in Singapore. Singapore Med J 2002;43:296-9.  Back to cited text no. 13
Ahmed A, Usman J, Hashim R. Isolates from chronic suppurative otitis media and their antimicrobial sensitivity. Pak Armed Forces Med J 1999;49:82-5.  Back to cited text no. 14
Agrawal A, Kumar D, Goyal A, Goyal S, Singh N, Khandelwal G. Microbiological profile and their antimicrobial sensitivity pattern in patients of otitis media with ear discharge. Indian J Otol 2013;19:5-8.  Back to cited text no. 15
  [Full text]  
Shyamla R, Reddy SP. The study of bacteriological agents of chronic suppurative otitis media–aerobic culture and evaluation. J Microbiol Biotechnol Res 2012;2:152-62.  Back to cited text no. 16
Osazuwa F, Osazuwa E, Osime C, Igharo EA, Imade PE, Lofor P, et al. Etiologic agents of otitis media in Benin city, Nigeria. North Am J Med Sci 2011;3:95-8.  Back to cited text no. 17
  [Full text]  
Mansoor T, Musani MA, Khalid G, Kamal M. Pseudomonas aeruginosa in chronic suppurative otitis media: Sensitivity spectrum against various antibiotics in Karachi. J Ayub Med Coll Abbottabad 2009;21:120-3.  Back to cited text no. 18
Ettehad GH, Refahi S, Nemmati A, Pirzadeh A, Daryani A. Microbial and antimicrobial susceptibility patterns from patients with chronic otitis media in Ardebil. Int J Trop Med 2006;1:62-5.  Back to cited text no. 19
Nwokoye NN, Egwari LO, Coker AO, Olubi OO, Ugoji EO, Nwachukwu SCU, et al. Predisposing and bacteriological features of otitis media. Afr J Microbiol Res 2012;6:520-5.  Back to cited text no. 20
Rao R, Bhaskaran CS. Bacteriology of chronic suppurative otitis media with special reference to anaerobes. Indian J Pathol Microbiol 1984;27:341-6.  Back to cited text no. 21
Vijaya D, Nagarathnamma T. Microbiological study of chronic suppurative otitis media. Indian J Otol 1998;4:172-4.  Back to cited text no. 22
Fatma AA, Assiry S, Siraj MZ. Microbiological evaluation and aspects on the management of chronic suppurative otitis media in Riyadh. Indian J Otol 1998;4:115-20.  Back to cited text no. 23
Chakraborty A, Bhattacharjee A, Purkaystha P. Microbiological profile of chronic suppurative otitis media: Its significance in North-East India. Indian J Otol 2005;11:39-44.  Back to cited text no. 24
Iseh KR, Adegbite T. Pattern and bacteriology of acute suppurative otitis media in Sokoto, Nigeria. Ann Afri Med 2004;3:164-6.  Back to cited text no. 25
Aslam MA, Ahmed Z, Azim R. Microbiology and drug sensitivity patterns of chronic suppurative otitis media. J Coll Physicians Surg Pak 2004;14:459-61  Back to cited text no. 26
Weckwerth PH, Lopes CA, Duarte MA, Weckwerth AC, Martins CH, Neto DL, et al. Chronic suppurative otitis media in cleft palate: Microorganism aetiology and susceptibilities. Cleft Palate Craniofac J 2009;46:461-7.  Back to cited text no. 27
Maji PK, Chatterjee TK, Chatterjee S, Chakrabarty J, Mukhopadhyay BB. The investigation of bacteriology of chronic suppurative otitis media in patients attending a tertiary care hospital with special emphasis on seasonal variation. Indian J Otolaryngol Head Neck Surg 2007;59:128-31.  Back to cited text no. 28
Dayasena R, Dayasiri M, Jayasuriya C, Perera D. Aetiological agents in chronic suppurative otitis media in Sri Lanka. Australas Med J 2011;4:101-4.  Back to cited text no. 29
Deb T, Ray D. A study of the bacteriological profile of chronic suppurative otitis media in Agartala. Indian J Otolaryngol Head Neck Surg 2012;64:326-9.  Back to cited text no. 30


  [Table 1], [Table 2], [Table 3], [Table 4]


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