Butyrate Disc Test

 The Butyrate Disc Test is to used to detect the presence of butyrate esterase in bacterial colonies isolated on culture media for the presumptive identification of Moraxella (Branhamella) catarrhalis. 

 

Moraxella (Branhamella) catarrhalis once thought to be a non-pathogenic organism is now considered a possible agent in respiratory infections.  M.catarrhalis can be found at the same sites as pathogenic Neisseria spp. and shares some similar physiological and biochemical characteristics, it is important to have a screening test for the differentiation of Moraxella catarrhalis2.  The Butyrate Disc Test demonstrates the enzymatic hydrolysis of bromo-chloro-indolyl butyrate, which creates a blue color reaction.  Neisseria spp. do not hydrolyze so this substrate and will remain colorless. 

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Infections of the respiratory tract account for the majority of clinical conditions involving M.catarrhalis as an etiologic agent.  These infections include otitis media, sinusitis, bronchitis, and pneumonia. Although otitis media caused by this organism may occur at any age, most studies show that infections are prevalent in the pediatric population.

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In one study the prevalence of M.catarrhalis in children with respiratory tract infections was 68%. A Study of nasopharyngeal colonization with M.catarrhalis during the first two years of life showed that 66% of 120 cultures obtained from children become colonized during the first year and that 77.5% were colonized by the end of the second year.  Higher colonization rates have also been seen in preschool children with asthma (70%) than in healthy children (33%).(1)

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SDS   |   Package Insert

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(1) Riou, J.Y. et al.:”Hydrolyse de la tributyrine par les Neisseria et les Branhamella”. (French). Ann.Microbiol. (Ins.Pasteur) 132A, 159-169 (1981).