title: Post Neurosurgical Meningitis due to Colistin Heteroresistant Acinetobacter baumannii.
abstract: BACKGROUND
  Recently Acinetobacter baumannii isolates have emerged as a problematic infectious agent that causes meningitis in neurosurgical patients. Colistin has been used successfully for the treatment of A. baumannii meningitis but colistin resistant isolates have been reported worldwide.
  
  
  METHODS
  Two isolates of A. baumannii were cultured during a five-day period from cerebrospinal fluid (CSF) samples of a 20-year-old man with a gunshot trauma in the abdomen, which had exited from his back. Antimicrobial susceptibility tests of isolates were performed. Multiplex PCR was performed for detection of bla OXA-23-like, bla OXA-24-like and bla OXA-58-like genes. Metallo-β-lactamase genes such as: bla VIM, bla IMP, bla SPM and bla NDM were sought by singleplex PCR. In order to evaluate the genetic relationship, two isolates were examined by the repetitive extragenic palindromic-polymerase chain reaction (REP_PCR) method.
  
  
  CONCLUSIONS
  E-test results showed that the isolates were sensitive to colistin and tigecycline with minimum inhibitory concentration of (MIC) 0.25 µg/mL and 1.5 µg/mL, respectively. Secondly the isolates were resistant to colistin with MIC > 256 µg/mL but remained sensitive to tigecycline with MIC 1.5 µg/mL. On the basis of the multiplex PCR, both of the isolates were positive for bla OXA-23-like. Other investigated genes such as bla OXA-24-like, bla OXA-58-like, bla VIM, bla IMP, bla SPM and bla NDM were negative. REP-PCR results showed that two isolates were derived from a single strain and both were the same. The results of our study revealed that the firs isolate of A. baumannii was colistin heteroresistant and was changed to completely resistant during therapy. Diagnosis and treatment of A. baumannii meningitis is very important and to avoid treatment failure we suggest that all A. baumannii isolates obtained from CSF should be evaluated properly for colistin heteroresistance.
authors: Microbiology Department, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors: Mojtaba
authors: M
authors: Moosavian
authors: Microbiology Department, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Infectious and Tropical Diseases Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, IR Iran.
authors: Saeed
authors: S
authors: Shoja
authors: Infectious and Tropical Diseases Research Center, Razi Hospital, Infectious and Tropical Disease Ward, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors: Roohangiz
authors: R
authors: Nashibi
authors: Microbiology Department, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors: Nasim
authors: N
authors: Ebrahimi
authors: Genetic Department, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors: Mohammad Amin
authors: MA
authors: Tabatabaiefar
authors: Microbiology Department, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors: Soodabeh
authors: S
authors: Rostami
authors: Microbiology Department, Qazvin University of Medical Sciences, Qazvin, IR Iran.
authors: Amir
authors: A
authors: Peymani
keywords: Acinetobacter baumannii; Colistin; Meningitis; Neurosurgery
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