Carbapenem-Resistant Gram Negative Bacilli Are Predominantly Multidrug or Pan-Drug Resistant

Microb Drug Resist. 2021 Aug;27(8):1057-1062. doi: 10.1089/mdr.2020.0294. Epub 2021 Jan 8.


Carbapenems, although originally introduced against multidrug-resistant (MDR) Gram negative bacilli (GNB), are now advocated for initial empiric use resulting in increasing carbapenem-resistant (CR) GNB. In this study, we analyzed the frequencies of CR-GNB and compared their resistance patterns against other antibiotics. Overall, 42% (1,014/2,420) of CR-GNB were isolated (range: 29-59%), with similar frequencies among hospitalized and community-acquired infections. However, the CR frequencies in Acinetobacter baumannii were significantly higher in the hospitalized patients (>50%). In addition, the CR-GNB isolates showed significantly higher resistance to the other antibiotics-fluoroquinolones, aminoglycosides, sulfonamides, and ureidopenicillins compared to carbapenem-sensitive isolates, thereby limiting further treatment options. Majority of CR-GNB isolates were extended spectrum β-lactamase producers (38-72%) and MDR (19-61%). Pan-drug resistant (PDR) frequencies among these MDR isolates ranged from 21% (Proteus spp.) to 100% (A. baumannii). Overall, CR-GNB are predominantly MDR or PDR and so warrant continuous antibiotic surveillance to provide better management of the infectious diseases.

Keywords: Gram negative bacilli; carbapenem-resistant; colistin; multidrug-resistant; pan-drug resistant.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology*
  • Carbapenems / pharmacology*
  • Child
  • Child, Preschool
  • Drug Resistance, Multiple, Bacterial / physiology*
  • Female
  • Gram-Negative Bacteria / drug effects*
  • Gram-Negative Bacteria / isolation & purification
  • Humans
  • India / epidemiology
  • Infant
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Poverty
  • Tertiary Care Centers
  • Young Adult
  • beta-Lactamases / biosynthesis


  • Anti-Bacterial Agents
  • Carbapenems
  • beta-Lactamases