title: Multi drug resistance and Extended Spectrum Beta Lactamases in clinical isolates of Shigella: A study from New Delhi, India.
abstract: BACKGROUND
  Shigella is an important cause of gastroenteritis in local Indian population, as well as of traveler's diarrhea in the international visitors to India. These patients often require appropriate antimicrobial therapy; however, rapid development of antimicrobial resistance poses a major hurdle in achieving this goal.
  
  
  METHODS
  A prospective study was conducted during 2009-12 in New Delhi, India, including 6339 stool samples from gastroenteritis patients. 121 Shigella strains were identified on the basis of colony morphology, biochemical reactions, serotyping and ipaH gene based PCR. Antimicrobial susceptibility testing by disc diffusion, MIC determination by Vitek(®) 2 and phenotypic tests for ESBL/AmpC production were done.
  
  
  RESULTS
  Nineteen percent strains (23/121) were found to be resistant to third generation cephalosporins and all were phenotypically confirmed to be ESBL producers; one strain was positive for AmpC. ESBL producing strains were also found to be significantly more resistant (p < 0.05) to several other antimicrobials agents in comparison to ESBL non-producers, [ampicillin (100% vs. 62.2%), ampicillin/sulbactam (100% vs. 30.6%), cotrimoxazole (100% vs. 77.6%), ciprofloxacin (87.0% vs. 49.0%), ofloxacin (87.0% vs. 52.0%) and gentamicin (30.4% vs. 7.1%)]. Multidrug resistance was seen in 76% strains.
  
  
  CONCLUSIONS
  Inappropriate use of antimicrobial agents puts high selection pressure on the higher-end antibiotics. Multi-drug resistance and high rates of ESBL production by Shigella is a matter of concern for the local population as well as international travelers. Therefore, better national level antimicrobial management programs are the priority needs.
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India. Electronic address: prabhavaggarwal@yahoo.co.in.
authors.forename: Prabhav
authors.initials: P
authors.lastname: Aggarwal
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: Beena
authors.initials: B
authors.lastname: Uppal
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: Roumi
authors.initials: R
authors.lastname: Ghosh
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: S
authors.initials: S
authors.lastname: Krishna Prakash
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Chakravarti
authors.affiliation: Department of Microbiology, Maulana Azad Medical College, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Jha
authors.affiliation: Department of Pediatrics, Maulana Azad Medical College and Associated Lok Nayak Hospital, Bahadur Shah Zafar Road, New Delhi 110002, India.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Rajeshwari
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004405:Dysentery, Bacillary / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007194:India / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012703:Serotyping; D012760:Shigella / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D014195:Travel; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C063500:ipaH protein, Shigella flexneri; D001618:beta-Lactamases
keywords: Antimicrobial susceptibility testing; Diarrhea; Dysentery; Minimum inhibitory concentration