. 2016 Jun 3;21(3):286–296. doi: 10.1055/s-0036-1584294

Table 2. Prevalence of beta-lactamase–producing bacteria in excised tonsils.

Investigators (country, year)	No. of Patients	% β lactamase producing bacteria
Brook et al ²⁴ (USA, 1981)	50	74
Reilly et al ²⁵ (UK, 1981)	41	78
Tuner and Nord ²⁶ (Sweden, 1982)	167	73
Chagollan et al ²⁷ (Mexico, 1984)	10	80
Kielmovitch et al ²⁸ (USA, 1989)	25	100
Brook et al ²⁹ (USA, 1995)	50	94