Back to the Future: Penicillin-Susceptible Staphylococcus Aureus.
Am J Med. 2016 Feb 25;
Authors: Cheng MP, René P, Cheng AP, Lee TC
BACKGROUND: Widespread penicillin usage rapidly resulted in the emergence of penicillin resistance in Staphylococcus aureus. However, new data suggests that penicillin susceptibility may be in a period of renaissance. The objective of our study was to quantify penicillin resistance in methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.
METHODS: We retrospectively reviewed all adult MSSA bacteremia from April 2010 to April 2015 at the McGill University Health Centre (Montreal, Canada). Susceptibility to penicillin, erythromycin, clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX) were determined in accordance with the Clinical & Laboratory Standards Institute guidelines.
RESULTS: There were 324 unique episodes of MSSA bacteremia. 90 (28%) isolates were susceptible to penicillin, 229 (71%) to erythromycin, 239 (74%) to clindamycin and 317 (98%) to TMP-SMX. Isolates that were penicillin resistant were more likely to also be resistant to other antibiotics, but a statistically significant association was apparent only for erythromycin resistance (76/234, 32.2% vs. 19/90, 21.1%, p=0.04). The median age of patients was 67.5 years (IQR 52-78) and overall in-hospital 30-day mortality was 16.3% (53 deaths). After adjustment for patient age, there was no association between penicillin resistance and either ICU admission or death.
CONCLUSION: More than one quarter of patients with MSSA bacteremia could potentially be treated with parenteral penicillin, which may offer pharmacokinetic advantages over other beta-lactam drugs and potentially improved outcomes.
PMID: 26924388 [PubMed - as supplied by publisher]