Microbiota in chagasic megaesophagus / Microbiota no megaesôfago chagásico.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

The stasis of saliva and swallowed food in the esophageal lumen of patients with chagasic megaesophagus causes: (1) bacterial overgrowth in the esophageal lumen, (2) recurring pulmonary aspirations and respiratory infections, (3) increased risk of surgical or endoscopic procedures if perforation occurs by the major possibility of contamination, and (4) the development of chronic inflammatory process in esophageal mucosa, that can predispose to the development of dysplasia and cancer. In spite of this, esophageal microbiota in the megaesophagus has never been studied. The aim of this study was to analyze qualitatively and quantitatively the microbiota in chagasic megaesophagus in comparison to the normal esophagus. Twenty-five patients (10 men and 15 women) were prospectively studied, with ages varying from 24 to 74 years (=49,1), from March to September 2000. Fifteen patients with chagasic megaesophagus (MG), were divided into three sub- groups according to the grade of esophageal dilation: MG1 – 5 patients with megaesophagus grade I; MG2- 5 patients with megaesophagus grade II; MG3- 5 patients with megaesophagus grade III. Another group of ten patients without any esophageal disease was constituted in the Control Group (CG). The sample collection was performed using a method specially developed to avoid contamination with microorganisms of the oral cavity and oropharynx. After qualitative and quantitative analysis, the microorganisms found were described and classified as Gram positive aerobes, Gram negative aerobes, anaerobes and fungus. Statistical analysis using Kruskal-Wallis non-parametric test was performed in order to find quantitative differences of microorganisms in the different groups. In CG 40% of the cultures were positive with predominance of the genus Streptococcus sp, in concentrations that varied from 101 to 102 cfu/ml. In MG, 93,3% of the cultures were positive, with great bacterial variability and predominance of a variety of aerobic Gram-positive (Streptococcus sp was the most common) and anaerobic bacteria (Veillonella sp was the most frequent), in concentrations that varied from 101 to 105 cfu/ml. The bacterial concentrations were generally more elevated in MG3 in comparison to MG1, MG2 and CG (p<0,05). It was concluded that patients with megaesophagus present a varied microbiota constituted mostly of aerobic Gram positive and anaerobic bacteria, in concentrations that vary with the megaesophagus dilatation degree. Some of the bacteria found in MG are able to metabolize nitrates intro nitrites, an important step in the formation of nitrosamines.

ASSUNTO(S)

megaesôfago achalasia composto nitroso/análise chagas disease/ethiology esophageal achalasia/microbiology nitroso compounds/analysis microbiologia megaesophagus doença de chagas/etiologia acalasia esofágica/microbiologia microbiology nitrate reductases/analysis acalasia nitrato reductases/análise

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