Geographical and temporal variation in the frequency and antimicrobial susceptibility of bacteria isolated from patients hospitalized with bacterial pneumonia: results from 20 years of the SENTRY Antimicrobial Surveillance Program (1997-2016)

Background: The SENTRY Antimicrobial Surveillance Program monitors the frequency of occurrence and antimicrobial susceptibility of organisms from various infection types worldwide. Methods: A total of 102 995 bacterial isolates were consecutively collected (one per patient) in 1997-2016 from 258 medical centres in North America (n=44 999; 113 centres), Europe (n=30 988; 61 centres from 22 nations), the Asia-Pacific region (APAC; n=16 503; 67 centres from 12 nations) and Latin America (n=10 505; 17 centres from 7 nations). Organisms were isolated from respiratory tract specimens and tested for susceptibility by broth microdilution methods in a central laboratory. Results: Staphylococcus aureus (n=24 351) and Pseudomonas aeruginosa (n=22 279) were the most common organisms overall. Klebsiella spp. (n=10 565) ranked third in North America, Europe and APAC. The proportion of Gram-negatives increased from 70.0%-74.7% to 80.9%-82.6% in Europe, APAC and Latin America, and remained stable (65.5%-66.1%) in North America. Methicillin resistance rates decreased substantially in all four regions from 2005-06 to 2015-16 among S. aureus isolates. P. aeruginosa susceptibility to meropenem decreased overall in the initial years, but increased in the last years of the investigation. Among Klebsiella spp. isolates, susceptibility to ceftriaxone/meropenem decreased from 85.9%/99.3% to 58.6%/85.8% in Europe and from 91.8%/99.5% to 81.6%/93.9% in APAC during the study period. Conclusions: Rank order and susceptibility rates varied widely by geographical region and over time. The occurrence of some resistance phenotypes increased, though others decreased over the 20 years of the SENTRY Antimicrobial Surveillance Program.