| prevalence of beta-lactamases among 1,072 clinical strains of proteus mirabilis: a 2-year survey in a french hospital. | beta-lactam resistance was studied in 1,072 consecutive p. mirabilis clinical strains isolated at the clermont-ferrand teaching hospital between april 1996 and march 1998. the frequency of amoxicillin resistance was 48.5%. among the 520 amoxicillin-resistant isolates, three resistance phenotypes were detected: penicillinase (407 strains [78.3%]), extended-spectrum beta-lactamase (74 strains [14. 2%]), and inhibitor resistance (39 strains [7.5%]). the penicillinase phenotype isolates were divided ... | 2000 | 10858357 |