Presence of metallo-beta-lactamases (MBL), extended-spectrum beta-lactamase (ESBL) & AmpC positive non-fermenting gram-negative bacilli among intensive care unit patients with special reference to molecular detection of blaCTX-M & blaAmpC genes

Richa Gupta, Abida Malik*, Meher Rizvi, Moied Ahmed

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


Background & objectives: Non-fermenting Gram-negative bacilli (NFGNB) including Pseudomonas aeruginosa and Acinetobacter baumannii have been implicated in a variety of infections, particularly in the Intensive Care Units (ICUs). This study was aimed to overview the burden of multidrug-resistant NFGNB causing infections in ICU and also to assess the occurrence of extended-spectrum beta-lactamases (ESBLs), AmpC and metallo-beta-lactamases (MBLs) among these isolates. Methods: Bacterial culture, identification and antibiotic susceptibility were carried out. ESBLs and AmpC were detected both phenotypically and genotypically. MBL was detected by modified Hodge and imipenem-ethylenediaminetetraacetic acid double-disc synergy test. Results: NFGNB represented 45 (37%) of total 121 Gram negative isolates. Multidrug resistance was observed in 66.9 per cent and 72.5 per cent isolates of P. aeruginosa and A. baumannii, respectively. Detection by phenotypic methods showed presence of ESBL, AmpC and MBL in 21.4, 51.1 and 21.4 per cent isolates, respectively. When detected genotypically by polymerase chain reaction, ESBL and AmpC were detected in 21.4 and 41.4 per cent of NFGNB isolates, respectively. BlaCTX-M (21.4%) was the most prevalent gene responsible for ESBL production. Interpretation & conclusions: Most of the NFGNB isolated from ICU patients were multidrug-resistant and producers of ESBL, AmpC and MBL. A regular surveillance is required to detect ESBL, AmpC and MBL producers, especially in ICU patients.

Original languageEnglish
Pages (from-to)271-275
Number of pages5
JournalIndian Journal of Medical Research
Issue numberAugust
Publication statusPublished - 2016
Externally publishedYes


  • Acinetobacter baumannii
  • Intensive care unit
  • Multidrug-resistance
  • Pseudomonas aeruginosa

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this