title: [Megaesophagus microbiota and carcinogenesis].
abstract: BACKGROUND
  The risk of development of spin cell carcinoma of the esophagus is 33 times higher in patients with chagasic achalasia. It is possible that the production of N-nitroso compounds in the esophageal lumen by of bacterial action in the stasis liquid that reduce nitrates from diet into nitrites may play a role in this process.
  
  
  OBJECTIVE
  To analyze qualitatively and quantitatively the microbiota in chagasic megaesophagus with special attention to bacteria capable of transforming nitto reduction.
  
  
  METHODS
  Fifteen patients (six men and nine women) were prospectively studied, with ages varying from 28 to 73 years. Patients were divided into three sub-groups according to Rezende et al. classification of esophageal dilation (grade I, grade II and grade III).
  
  
  METHODS
  The sample collection was performed using a method specially developed to avoid contamination with microorganisms of the oral cavity and oropharynx, using a Levine catheter n 14 and a 7,5 oro-traqueal tube.
  
  
  RESULTS
  Ninety three point three percent of the cultures were positive, with great bacterial variability and predominance of a variety of aerobic Gram-positive and anaerobic bacteria. The bacterial concentrations were generally more elevated in grade III in comparison to grade I and grade II. Among the microorganisms found, Staphylococcus sp, Corynebacterium sp, Peptostreptococcus sp e a Veillonella sp were those with the capability of nitrate reduction.
  
  
  CONCLUSIONS
  It was concluded that patients with megaesophagus present some bacteria in the esophageal lumen that are able to reduce nitrates intro nitrites, an important step in the formation of N-nitroso compounds.
authors.affiliation: Disciplina de Cirurgia do Aparelho Digestivo, Departamento de Gastroenterologia, Faculdade de Medicina, Universidade de São Paulo, Belo Horizonte, MG, Brasil. pajecki@netpoint.com.br
authors.forename: Denis
authors.initials: D
authors.lastname: Pajecki
authors.forename: Bruno
authors.initials: B
authors.lastname: Zilberstein
authors.forename: Manoel Armando Azevedo
authors.initials: MA
authors.lastname: dos Santos
authors.forename: Alina Guimarães
authors.initials: AG
authors.lastname: Quintanilha
authors.forename: Ivan
authors.initials: I
authors.lastname: Cecconello
authors.forename: Joaquim
authors.initials: J
authors.lastname: Gama-Rodrigues
mesh_terms: D000328:Adult; D000368:Aged; D001420:Bacteria, Aerobic / Q000302:isolation & purification; D001421:Bacteria, Anaerobic / Q000302:isolation & purification; D014355:Chagas Disease / Q000150:complications / Q000382:microbiology*; D015169:Colony Count, Microbial; D004108:Dilatation, Pathologic; D004931:Esophageal Achalasia / Q000209:etiology / Q000382:microbiology*; D004938:Esophageal Neoplasms / Q000209:etiology / Q000382:microbiology*; D004947:Esophagus / Q000382:microbiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000378:metabolism; D009603:Nitroso Compounds / Q000378:metabolism; D011446:Prospective Studies
chemical_list: D009566:Nitrates; D009603:Nitroso Compounds