The hypothesis that Helicobactermight be a risk factor for human liver diseases has arisen after the detection of Helicobacter DNA in hepatic tissue of patients with hepatobiliary diseases. Nevertheless, no explanation that justifies the presence of the bacterium in the human liver has been proposed. We evaluated the presence of Helicobacterin the liver of patients with hepatic diseases of different aetiologies. We prospectively evaluated 147 patients (106 with primary hepatic diseases and 41 with hepatic metastatic tumours) and 20 liver donors as controls. Helicobacter species were investigated in the liver by culture and specific 16S rDNA nested-polymerase chain reaction followed by sequencing. Serum and hepatic levels of representative cytokines of T regulatory cell, T helper (Th)1 and Th17 cell lineages were determined using enzyme linked immunosorbent assay. The data were evaluated using logistic models. Detection of Helicobacter pylori DNA in the liver was independently associated with hepatitis B virus/hepatitis C virus, pancreatic carcinoma and a cytokine pattern characterised by high interleukin (IL)-10, low/absent interferon-γ and decreased IL-17A concentrations (p < 10-3). The bacterial DNA was never detected in the liver of patients with alcoholic cirrhosis and autoimmune hepatitis that are associated with Th1/Th17 polarisation. H. pylori may be observed in the liver of patients with certain hepatic and pancreatic diseases, but this might depend on the patient cytokine profile.

O tecido perirradicular de 30 casos cirúrgicos foi submetido a exame microbiológico e histopatológico. Foram isoladas 137 cepas bacterianas das 30 lesões periapicais estudadas. Do total de bactérias isoladas, 90 (65,7%) foram caracterizadas como anaeróbias estritas, 40 (29,2%) como anaeróbias facultativas e 7 (5,1%) como aeróbias estritas. Fusobacterium nucleatum, bacilos Gram-negativos pigmentados anaeróbios estritos, Peptostreptococcus sp, Streptococcus mitis e bacilos Gram-positivos não esporulados anaeróbios estritos foram, em ordem decrescente de freqüência, as bactérias mais comumente isoladas das lesões periapicais. A análise histopatológica demonstrou prevalência de granuloma periapical. O estudo de sensibilidade a antimicrobianos foi realizado em 16 cepas de Fusobacterium nucleatum. Os antimicrobianos utilizados foram penicilina, cefoxitina, eritromicina, metronidazol e tetraciclina. Todas as amostras apresentaram suscetibilidade à cefoxitina, tetraciclina e metronidazol; os percentuais de resistência à penicilina e à eritromicina foram 12,5 e 68,8, respectivamente. Os percentuais de resistência de Fusobacterium nucleatum, uma espécie bacteriana importante na patogênese das lesões periapicais, à penicilina e à eritromicina, enfatizam a necessidade de outros estudos de resistência a antimicrobianos de bactérias isoladas em infecções odontogênicas.

Periapical tissue from 30 individuals requiring dental surgery was examined histologically and cultured for the presence of bacteria. A total of 137 strains of bacteria were isolated and of the isolates, 65.7% were strict anaerobes, 29.2%, facultative anaerobes and 5.1%, strict aerobes. Fusobacterium nucleatum was the species most frequently isolated, followed by pigmented strict anaerobes, Peptostreptococcus sp and Streptococcus mitis. In all cases more than one bacterial species was found. The histological analysis demonstrated prevalence of periapical granuloma. Fusobacterium nucleatum isolated from 16 patients was tested for susceptibility to penicillin, cefoxitin, erythromycin, metronidazole and tetracycline. All strains were susceptible to cefoxitin, metronidazole and tetracycline and the resistance rates to penicillin and erythromycin were 12.5 and 68.8% respectively. The resistance rates of F. nucleatum, an important bacterium in periapical infection to penicillin and erythromycin emphasize the need to further study antimicrobial resistance of bacteria isolated from odontogenic infections.