The role of IFN-gamma and IL-4 in gastric mucosa inflammation associated with Helicobacter heilmannii type 1 infection

Although Helicobacter heilmannii infection is less common than H. pylori infection in humans, it is considered to be of medical importance because of its association with gastritis, gastric ulcer, carcinoma, and mucosa-associated lymphoid tissue lymphoma of the stomach. However, there have been no studies evaluating the role of the Th cell response in H. heilmannii gastric infection. We evaluated the participation of pro-inflammatory and anti-inflammatory cytokines, IFN-gamma and IL-4, in H. heilmannii gastric infection in genetically IFN-gamma- or IL-4-deficient mice. The serum IFN-gamma and IL-4 concentrations were determined by ELISA. The gastric polymorphonuclear infiltrate was higher (P = 0.007) in H. heilmannii-positive than in H. heilmannii-negative wild-type (WT) C57BL/6 mice, whereas no significant inflammation was demonstrable in the stomach of H. heilmannii-positive IFN-gamma-/- C57BL/6 mice. The degree of gastric inflammatory cells, especially in oxyntic mucosa, was also higher (P = 0.007) in infected IL-4-/- than in WT BALB/c mice. Serum IFN-gamma levels were significantly higher in IL-4-/- than in WT BALB/c mice, independently of H. heilmannii-positive or -negative status. Although no difference in serum IFN-gamma levels was seen between H. heilmannii-positive (11.3 ± 3.07 pg/mL, mean ± SD) and -negative (11.07 ± 3.5 pg/mL) WT BALB/c mice, in the group of IL-4-/- animals, the serum concentration of IFN-g was significantly higher in the infected ones (38.16 ± 10.5 pg/mL, P = 0.04). In contrast, serum IL-4 levels were significantly decreased in H. heilmannii-positive (N = 10) WT BALB/c animals compared to the negative (N = 10) animals. In conclusion, H. heilmannii infection induces a predominantly Th1 immune response, with IFN-gamma playing a central role in gastric inflammation.

Hepatic changes in mice chronically infected with Helicobacter trogontum

We infected NIH germ-free female mice with Helicobacter trogontum, a recently described intestinal bacterium of rats, in order to study the lesions it induced in the liver of this host. Fifteen mice were challenged with a single dose of H. trogontum (test group) and killed 6, 12 and 18 months after inoculation (5 animals/group). Nine animals were challenged with 0.85 percent saline alone (control group) and killed at the same times. Fragments from the liver, cecum and colon were obtained for microbiologic and histologic examination. Stool samples were also collected. H. trogontum was detected in the cecum, colon and/or stool samples of all test mice. As expected, the bacterium was not isolated from any specimen obtained from the control animals. On the other hand, although we could not cultivate the bacterium from the liver, 13 test animals (86.7 percent) presented histological changes in this organ. The 6-month group presented infiltration of mononuclear and polymorphonuclear cells in the hepatic parenchyma and the two other groups presented foci of mononuclear cells. The results suggest that H. trogontum can elicit a hepatic inflammatory response in mice since the only difference between control and test animals was the presence of H. trogontum in the latter. This result, together with the growing number of related reports in the literature, reinforces the possible role of Helicobacter infection in the pathogenesis of hepatobiliary diseases

Serodiagnosis of Helicobacter pylori infection by Cobas Core ELISA in adults from Minas Gerais, Brazil

We evaluated the accuracy of a 2nd generation ELISA to detect Helicobacter pylori infection in adults from a developing country in view of variations in sensitivity and specificity reported for different populations. We studied 97 non-consecutive patients who underwent endoscopy for evaluation of dispeptic symptoms. The presence of H. pylori was determined in antral biopsy specimens by culture, by the preformed urease test and in carbolfuchsin-stained smears. Patients were considered to be H. pylori positive if at least two of the three tests presented a positive result or if the culture was positive, and negative if the three tests were negative. Sixty-five adults (31 with peptic ulcer) were H. pylori positive and 32 adults were H. pylori negative. Antibodies were detected by Cobas Core anti-H. pylori EIA in 62 of 65 H. pylori-positive adults and in none of the negative adults. The sensitivity, specificity and positive and negative predictive values of the test were 95.4, 100, 100 and 91.4 per cent, respectively. The Cobas Core anti-H. pylori EIA presented high sensitivity and specificity when employed for a population in Brazil, permitting the use of the test both to confirm the clinical diagnosis and to perform epidemiologic surveys.

Mouse inoculation for the detection of non-cultivable gastric tightly spiralled bacteria

In the present study we compared the inoculation of swine gastric mucus into the stomach of mice, the urease test and carbolfuchsin-stained smears for the diagnosis of the infection with "Gastrospirillum suis" ("Helicobacter heilmmannii" type 1), an uncultivated tightly spiralled gastric bacterium. Fragments obtained from the antral and oxyntic mucosa of the stomach of 50 slaughtered pigs were used for urease test, for carbolfuchsin-stained smears and for obtaining scrapings of mucus for mouse inoculation. The mice were killed by spinal dislocation 10 days after inoculation and fragments of the antral and oxyntic mucosa were used for spiral bacterium identification (urease test and carbolfuchsin-stained smears).Among the method employed for the diagnosis of "H. heilmannii" infection, the inoculation of gastric mucus into the stomach of mice was the most sensitive and demonstrated bacterial positivity in 31 (62.0 percent) swine. Direct examination showed tightly spiralled bacteria in the gastric mucosa of only 4 (8.0 percent) of the 50 pigs studied. Among them, 3 (6.0 percent) presented a positive preformed urease test. Spiral bacteria were not seen in the gastric mucosa of any control mice. These results show that the use of the mouse inoculation method improved the detection of "H. heilmannii" in swine.

Comparison of the urease test and of direct smear examination in the control of treatment of Helicobacter pylori-induced infection

The sensitivity and specificity of the preformed urease test and of carbolfuchsin-stained smears for the diagnosis of the presence of Helicobacter pylori in gastric mucosa were evaluated before and after antimicrobial treatment. The results obtained by culture were used as the reference point. We studied 41 patients with endoscopically diagnosed duodenal ulcer. Twenty-five of these were treated with furazolidone (100 mg t.i.d.), amoxicillin (500 mg t.i.d.) and metronidazole (250 mg t.i.d.) for 5 days and then with only furazolidone (100 mg t.i.d.) for an additional 25 days. The 16 control patients were treated with cimetidine (800 mg, 4 times a day). The sensitivity of the urease test and of direct smear examination was 100 per cent before treatment and 84.6 per cent and 92.3 per cent , respectively, after treatment. We conclude that the urease test and carbolfuchsin-stained smears, which are highly sensitive for H. pylori diagnosis, present reduced sensitivity when they are employed for the follow-up of patients treated with antimicrobials

Chronic gastritis and Helicobacter pylori in digestive form of Chagas' disease

Patients with the digestive form of Chagas' disease frequently present chronic gastritis. As the microorganism Helicobacter pylori is now accepted as the most common cause of human chronic gastritis, the present work was undertaken to verify a possible relationship between the presence of this bacterium and inflammatory changes of antral mucosa in chagasic patients. Seventeen chagasics, with megaesophagus and or megacolon were studied. Fragments from two different regions of antral mucosa were obtained by endoscopy, fixed in 4 neutral formaldehyde and embedded in paraffin. The sections were stained by haematoxylin and eosin for histology analysis, and by carbolfuchsin for H. pylori identification. H. pylori was found in 16 (94.1) chagasic patients, all of them presenting chronic gastritis. Superficial gastritis was seen in 9 (52.9) while atrophic gastritis was present in 8 (47.1) patients. H. pylori was present on gastric mucosa of 8 (100) patients with atrophic gastritis and of 8 (88.8) patients with superficial gastritis. We concluded that the microorganism H. pylori should be considered a possible factor connected with the etiopathogenesis of chronic superficial and atrophic gastritis frequently observed in patients with the digestive form of Chagas' disease.

Indirect immunofluorescence determination of the frequency of anti-H. pylori antibodies in brazilian blood donors

The accuracy of an indirect immunofluorescence (IIF) test for the serodiagnosis of Helicobacter pylori infections was evaluated in adult patients and compared with culture, preformed urease test and smears stained with carbolfuchsin. We studied 80 consecutive patients submitted to gastroduodenioscopy (17 of whom were found to have duodenal ulcer) plus 57 patients with duodenal ulcer. H. pylori was identified by microbiological mehtods in 65 of the 80 consecutive patients and in all 57 patients with duodenal ulcer. Among the 74 patients with duodenal ulcer, 71 presented antibody titers *1:20 and 46 of the 48 H. pylori-positive patients without duodenal ulcer presented antibody titers *1:20. Thirteen of the 15 H. pylori-negative patients presented antibody titers *1:10. The sensitivity,m specificity and positive predictive value of the IIF test were 95.9%, 88.8% and 98.4%, respectively. The seroprevalence of H. pylori in 380 asymptomatic Brazilian was also studied by the IIF teset. The presence of IgG antibodies against H. pylori was observed in 62.1% of the individuals. The prevalence of H. pylori infection increased with age and no difference was observed between males (60.3%) and females (66.6%)

Diagnosis and distribution of Helicobacter pylori in the gastric mucosa of symptomatic children

The demonstration of the association of H, pylori with gastritis and peptic ulcer has been of increasing interest to gastroenterologists, microbiologists, and histopathologists. In this study, the presence of H, pylori in the gastric mucosa of children was investigated by culture, preformed urease test, and carbolfuchsin staining of biopsy smears. The organism was detected in 44,9% of the children studied, and found to be distributed equaly on the antral and fundic mucosa. Compared to culture, the urease test and carbolfuchsin staining proved to be of higher sensitivity and specificity in detecting H, pylori