Severe Acute Otitis Media Caused by Mucoid<i> Streptococcus Pyogenes</i> in a Previously Healthy Adult

Abstract

JapanStreptococcus (S.) pyogenes is well recognized as the most common pathogen causing pharyngotonsillitis in school-age children. In Japan, mucoid Streptococcus pneumoniae is well known as a causative agent of severe acute otitis media (AOM); however, mucoid S. pyogenes has rarely been reported. To the best of our knowledge, this is the first report of an AOM patient caused by mucoid S. pyogenes in Japan. A 36-year-old previously healthy female was referred to our hospital with suspicion of cerebrospinal otorrhea due to increasing otalgia accompanied by headache following myringotomy. Bacterial cultures of middle ear secretions were performed, and mucoid-form colonies surrounded by zones of complete β-hemolysis were produced on sheep's blood agar. Antigen-agglutination test results were positive for S. pyogenes, and thus the patient received treatment with panipenem-betamipron 2.0 g/day for 10 days, which resolved nearly all symptoms. The bacteriological features of this strain were then investigated. The M-protein genotype encoded by the emm gene, the major virulence factor of S. pyogenes, was determined to be emm75. Generally, S. pyogenes forms colonies having non-mucoid matt appearances based on β-hemolysis of sheep's blood agar. The mucoid phenotype results from abundant production of hyaluronic acid capsular polysaccharide, a key virulence determinant. emm75 is common in noninvasive, but less common in invasive disease. In conclusion, mucoid S. pyogenes can cause severe infection even in previously healthy persons. Emergence of mucoid S. pyogenes and drug resistance trends should be monitored in the future.

Species Identification of β-Hemolytic Streptococci from Diseased Companion Animals and Their Antimicrobial Resistance Data in Japan (2017)

“…Determination of species identification: DNA was extracted from the β-hemolytic streptococcal isolates by suspending in TE buffer and boiling at 97°C for 10 min as previously described (14). We identified the βhemolytic streptococcal strains at the species-level based on 16S rRNA sequencing data (13,15) (Table 1). The isolates identified were unambiguously identified, with ≥ 98.7% similarity to the 16S rRNA sequence of the corresponding strain.…”

Prevalence of M75 Streptococcus pyogenes Strains Harboring slaA Gene in Patients Affected by Pediatric Obstructive Sleep Apnea Syndrome in Central Italy

“…This very low macrolide resistance rate was further confirmed by a recent study conducted in the same area (Olivieri et al, 2015 ). In a study conducted in Portugal between 2,000 and 2,005, the genotype emm75/ST150 was significantly associated with pharyngitis (Friaes et al, 2012 ); however, interestingly, a mucoid form of a GAS strain M75/ST49 has recently been reported to cause a severe acute otitis media (Kakuta et al, 2014 ).…”

Characterization of Mucoid and Non-MucoidStreptococcus pneumoniaeIsolated From Outpatients

“…The capsule polysaccharide is the major virulence determinant of S. pneumoniae [ 11 ], particularly in hosts lacking type-specific antibodies of sufficient quantity or avidity [ 12 ]. Moreover, previous studies demonstrated that the mucoid phenotype, which is characterized by the presence of hyaluronic acid capsular polysaccharide in Streptococcus pyogenes , is a key virulence determinant associated with severe S. pyogenes infections [ 13 , 14 ]. The mucoid phenotype of S. pneumoniae may also show higher pathogenicity than the non-mucoid phenotype; therefore, it is important to characterize S. pneumoniae , especially the mucoid phenotype, with regard to antibiotic susceptibility.…”