Selection between aztreonam and cephalosporins for treatment of infections with pseudomonads needs more caution

• Main Author: Singh BR
• Format: Article
• Language: English
• Published: Dove Medical Press 2019-01-01
• Series: Infection and Drug Resistance
• Subjects: Aztreonam; Empiric antibiotic therapy; ESBL; Cephalosporins; AMR
• Online Access: https://www.dovepress.com/selection-between-aztreonam-and-cephalosporins-for-treatment-of-infect-peer-reviewed-article-IDR

Bhoj R Singh Division of Epidemiology, ICAR-Indian Veterinary Research Institute, Izatnagar, IndiaIn the recently published study1 to evaluate the use of aztreonam as an active empiric therapy against subsequent culture of Pseudomonas aeruginosa, empiric therapy failure using aztreonam is reported more common than on using β-lactam antibiotics in patients suffering P. aeruginosa infection. Though the study is interesting and revealing important findings regarding antibiotic use for treatment of P. aeruginosa infection, it should be accepted with caution as suggested by the authors1 repeatedly due to limited number of cases. In our observations on P. aeruginosa (95) and other pseudomonads (40) isolates from veterinary clinical cases we found that instead of generalizing the lesser efficacy of aztreonam in-depth studies are required. Although insignificant, aztreonam inhibited more numbers of extended spectrum β-lactamase (ESBL) producing (57) P. aeruginosa strains (56.1%) than most of the β-lactams including cefotaxime, ceftriaxone and piperacillin (53.3%). However, on non-ESBL producing (37) strains aztreonam inhibited 42.1% isolates, much less than cefepime (68%), ceftriaxone (50%) and piperacillin + tazobactam (61.1%). Therefore, it is suggested to use the two classes of antibiotics (aztreonam and β-lactams) judiciously based on antibiotic stewardship principle1 instead of following some general rule for infections with pseudomonads. Authors’ reply Michael Hogan,1 Mary Barna Bridgeman,1 Gee Hee Min,1 Deepali Dixit,1 Patrick J Bridgeman,1 Navaneeth Narayanan1,21Department of Pharmacy Practice and Administration, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA; 2Division of Infectious Diseases, Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA We appreciate the author of this letter reading our article with such great interest. We believe, however, in this response that here is limited application to the context and overall content of our clinical study of human patients. First, the data cited n this response are from veterinary clinical cases. Though general principles of understanding of antibiotic sensitivity testing and resistance mechanisms apply regardless of species, there are major differences that impede reasonable comparisons between the assertions in this letter and findings of our original study. View the original paper by Hogan and colleagues