Antibiotic resistance to available microorganisms has been constant since the introduction of sulfonamides in the 1930s. Multidrug resistant Pseudomonas aeruginosa and β-lactamase producing Staphylococcus aureus become a matter of great concern now because of the importance of these pathogens in middle ear infection of infants and children.
The risk factors for the development of resistance in otitis media include improper and indiscriminate use of antimicrobial, young age, tobacco smoke, male gender, day-care attendance and immunodeficiency. The understanding of the pathogenesis of acute otitis media (AOM) was the basis of discovering effective strategies in the management of this disease. According to Lim et al. in 2000and the sterility become maintained by the mucociliary system and by the enzymes and antibodies secreted by the epithelial cells of the Eustachian tube and the middle ear. Henderson et al. in 1982 and Heikkinen et al. in 1995 reported that although AOM is usually a bacterial infection but often proceeded by a respiratory viral infection. The same otitis pathogens that were found in middle ear effusion also found in the nasopharynx (Loos et al. 1989). Although AOM can occur at any age, it is most common in young children, particularly at the age of 6–24 months (Pukander et al 1982; Lundgren and Ingvarsson 1983; Teele et al. 1989). A genetic component engrossed in the predisposition to middle ear infections (Casselbrant and Mandel 2001).
Cefepime, the fourth generation cephalosporin has provided a new therapeutic possibility, offering a wide range of antibacterial activity and proven concentration in the middle ear.
Amoxicillin also used for treatment of otitis media but its major drawback was limited efficacy when β-lactamase producing bacteria were the major causative microorganisms. Klebsiella pneumoniae and Bacteroide spp. rarely caused acute otitis media (Robert 1992). Despite the availability of many other drugs, amoxicillin is still the drug of first choice in most cases (Klein 1994; McCracken 1994). In 1989, Brook and Yocum found that in suppurative otitis media, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus were the most common bacteria. Mozafari Nia et al. in 2011 reported that the Staphylococcus aureus was the commonest aerobic isolate in CSOM. Pseudomonas isolates also showed complete (100%) resistance to amoxicillin/clavulanate. Our findings also correlate with Mozafari findings.
In 2002, AHC Loy et al. found that the most common causative organism of chronic suppurative otitis media are Pseudomonas aeruginosa (33.3%) and Staphylococcus aureus (33.3%) followed by coagulase negative Staphylococcus aureus (21.1%). Oni et al. (2001) reported that Pseudomonas aeruginosa was the predominant agent of chronic supprative otitis media and acute supprative otitis media. This was followed by Staphylococcus aureus. Kenna et al. (1986) reported that in chronic suppurative otitis media, the most common organisms are Pseudomonas aeruginosa and Staphylococcus aureus. According to Aslam et al. (2004) The commonest microorganisms isolated from chronic discharging ears were Pseudomonas aeruginosa and Staphylococcus aureus. This was also confirmed from our findings.
Among the cephalosporins, cefepime was used in the present study. All isolates of Pseudomonas aeruginosa were resistant to cefepime while only 12% isolates of Staphylococcus aureus (were resistant to cefepime. Ale Zehra et al. 2010) also found cefepime effective against Pseudomonas aeruginosa. Pseudomonas aeruginosa and Staphylococcus aureus are the most frequently isolated pathogens in patients with acute otitis media. The recent emergence of multidrug-resistant Pseudomonas aeruginosa and increasing frequency of β-lactamase producing strains of Staphylococcus aureus are creating problem regarding the use of amoxicillin as first line empiric therapy for acute otitis media in young children. The new fourth generation cephalosporin, cefepime is effective against multidrug -resistant Pseudomonas aeruginosa and β-lactamase producing strains of Staphylococcus aureus.