Lipid A-Ara4N as an alternate pathway for (colistin) resistance in Klebsiella pneumonia isolates in Pakistan

Kiran Iqbal Masood, Seema Umar, Zahra Hasan, Joveria Farooqi, Safina Abdul Razzak, Nazish Jabeen, Jason Rao, Sadia Shakoor, Rumina Hasan

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Objectives: This study aimed to explore mechanism of colistin resistance amongst Klebsiella pneumoniae isolates through plasmid mediated mcr-1 gene in Pakistan. Carbapenem and Colistin resistant K. pneumoniae isolates (n = 34) stored at − 80 °C as part of the Aga Khan University Clinical Laboratory strain bank were randomly selected and subjected to mcr-1 gene PCR. To investigate mechanisms of resistance, other than plasmid mediated mcr-1 gene, whole genome sequencing was performed on 8 clinical isolates, including 6 with colistin resistance (MIC > 4 μg/ml) and 2 with intermediate resistance to colistin (MIC > 2 μg/ml). Results: RT-PCR conducted revealed absence of mcr-1 gene in all isolates tested. Whole genome sequencing results revealed modifications in Lipid A-Ara4N pathway. Modifications in Lipid A-Ara4N pathway were detected in ArnA_ DH/FT, UgdH, ArnC and ArnT genes. Mutation in ArnA_ DH/FT gene were detected in S3, S5, S6 and S7 isolates. UgdH gene modifications were found in all isolates except S3, mutations in ArnC were present in all except S1, S2 and S8 and ArnT were detected in all except S4 and S7. In the absence of known mutations linked with colistin resistance, lipid pathway modifications may possibly explain the phenotype resistance to colistin, but this needs further exploration.

Original languageEnglish
Article number449
JournalBMC Research Notes
Issue number1
Publication statusPublished - Dec 2021


  • Antimicrobial drug resistance
  • Klebsiella pneumonia
  • mcr-1 gene


Dive into the research topics of 'Lipid A-Ara4N as an alternate pathway for (colistin) resistance in Klebsiella pneumonia isolates in Pakistan'. Together they form a unique fingerprint.

Cite this