title: [Features of resistance formation to beta-lactam antibiotics in Francisella tularensis subsp. mediasiatica].
abstract: OBJECTIVE
  Determination of penicillin resistance features in tularemia causative agents of the mediasiatica subspecies, stability evaluation of differences in strains of various taxa and development of a rapid method of F. tularensis intraspecies differentiation.
  
  
  METHODS
  Beta-lactamase activity was determined in 30 strains of Francisella genus bacteria by quantitative iodometric method.
  
  
  RESULTS
  All the strains regardless of subspecies membership were characterized by high resistance to beta-lactam antibiotics, and bacteria of the mediasiatica subspecies in contrast to other francisella did not synthesize beta-lactamase. Our attempts to induce beta-lactamase activity in vitro and in vivo in strains of this subspecies did not succeed. A method of intraspecies differentiation of F. tularensis by nitorcefin disks is proposed based on the distinctive feature.
  
  
  CONCLUSIONS
  A high level of F. tularensis subsp. mediasiatica resistance to beta-lactams in vitro and their inefficiency during therapy of experimental tularemia due to a beta-lactamase negative strain suggests that F. tularensis beta-lactamase is not the leading factor in formation of native penicillin resistance of tularemia causative agent.
authors.forename: M V
authors.initials: MV
authors.lastname: Tsimbalistova
authors.forename: N V
authors.initials: NV
authors.lastname: Pavlovich
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D005604:Francisella tularensis / Q000201:enzymology* / Q000235:genetics; D014406:Tularemia / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D018440:beta-Lactam Resistance / Q000187:drug effects* / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D047090:beta-Lactams; D001618:beta-Lactamases