Differential expression of ompC and ompF in multidrug-resistant Shigella dysenteriae and Shigella flexneri by aqueous extract of Aegle marmelos, altering its susceptibility toward beta-lactam antibiotics

Diagn Microbiol Infect Dis. 2008 Jul;61(3):321-8. doi: 10.1016/j.diagmicrobio.2008.02.006. Epub 2008 Mar 21.

Abstract

Steadily increasing resistance among Shigella to beta-lactams, aminoglycosides, and tetracycline has compromised the utility of these commonly used antimicrobial agents. Also, undesirable side effects of certain antibiotics have triggered immense interest in search of alternative therapies using medicinal plants. One such medicinal plant used since ancient times to cure diarrhea is Aegle marmelos. The present study exemplifies the susceptibility of beta-lactam-resistant Shigella dysenteriae and Shigella flexneri toward beta-lactam antibiotics, when grown in the presence of aqueous extract of A. marmelos (AEAM), by altering porin channels. This was demonstrated by antibiotic sensitivity test using disc diffusion method and MIC test. Susceptibility toward beta-lactam antibiotic is associated with changes in outer membrane porins OmpC (approximately 42 kDa) and OmpF (approximately 38 kDa) and cytosolic proteins of approximately 26 kDa, OmpR, a transcriptional regulator. Expression of ompF is increased in S. dysenteriae and S. flexneri grown in the presence of AEAM due to down-regulation of ompR, which is conformed by reverse transcriptase polymerase chain reaction. In conclusion, AEAM influences susceptibility of beta-lactam-resistant Shigella toward beta-lactam antibiotics by altering porin channels. Hence, AEAM along with beta-lactam can be used for treatment of multidrug-resistant Shigella.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aegle / chemistry*
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / biosynthesis
  • Gene Expression Profiling
  • Microbial Sensitivity Tests
  • Plant Extracts / pharmacology*
  • Porins / biosynthesis*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Shigella dysenteriae / drug effects*
  • Shigella dysenteriae / metabolism
  • Shigella flexneri / drug effects*
  • Shigella flexneri / metabolism
  • beta-Lactam Resistance*
  • beta-Lactams / pharmacology

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • OmpC protein
  • OmpF protein
  • Plant Extracts
  • Porins
  • beta-Lactams