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Biomedical subjects

H Rautelin

Publications and source records attributed to H Rautelin.

At least 73 records · Page 4Linked to original sources

Adhesion to and invasion of HeLa cells by Helicobacter pylori.

Eight clinical isolates and two reference strains of Helicobacter pylori were studied with regard to their interactions with HeLa cells. All the isolates adhered poorly to HeLa cells and the number of invasive bacteria was very low. No correlation was found between the adherence and invasiveness of the isolates on one hand, and the corresponding patients having ulcer or non-ulcer disease, or the ability of the strains to produce cytotoxin and to induce an oxidative burst of human polymorphonuclear leukocytes without opsonins, on the other. These results indicate that invasion of epithelial cells would play no important role in the pathogenesis of infections caused by H. pylori.

Bacterial Adhesion↗

Role of aeromonas isolated from feces of Finnish patients.

Aeromonas species were isolated from 249/13,027 (1.9%) stool samples submitted to the Dept. of Bacteriology and Immunology, University of Helsinki, during 1 year, to be cultured for bacterial enteropathogens. Aeromonas was the third most common enteropathogen isolated, after campylobacter (3.6%) and salmonella (3.3%). Isolates and clinical information from 234 Aeromonas patients were available for further study. A. caviae (41%), A. hydrophila (27%), and A. veronii biovar sobria (22%) were the most frequent isolates. In 15% of the patients, other enteropathogens were found along with aeromonas. Only 2% of all aeromonas-positive patients were found to be asymptomatic, whereas no aeromonas isolates were detected in the stools of 343 asymptomatic individuals. Almost all (96%) patients with aeromonas in their feces had gastroenteritis. Patients infected with A. veronii biovar sobria had a shorter illness course and had more often travelled abroad. In conclusion, Aeromonas spp. were found to be a potential cause of diarrhea in Finnish patients.

Adult↗

Enteric Plesiomonas shigelloides infections in Finnish patients.

Plesiomonas shigelloides was isolated from 20/13,027 stool samples submitted for culture to the Department of Bacteriology and Immunology, University of Helsinki, in 1990. All except 2/20 Plesiomonas-positive patients had diarrhea; 13 patients had acute onset of illness after foreign travel and 5 patients had chronic diarrhea with symptoms lasting > or = 2 months. Travel destinations were outside Europe in most cases. In 12 cases Plesiomonas was isolated in pure culture and in 8 cases together with other enteropathogens. All isolates were susceptible to ciprofloxacin, doxycycline, trimethoprim and sulfamethoxazole, gentamicin, cephalexin, cefuroxime, ceftriaxone and cefixime.

Adolescent↗

Ribotyping patterns and emergence of metronidazole resistance in paired clinical samples of Helicobacter pylori.

Metronidazole-susceptible pretreatment isolates and metronidazole-resistant posttreatment isolates of Helicobacter pylori from 11 patients before and after unsuccessful triple therapy consisting of metronidazole, amoxicillin, and colloidal bismuth subcitrate were studied. Ribotyping (rRNA gene restriction pattern analysis) of the isolates demonstrated that all patients except one had identical digest patterns for pre- and posttreatment isolates.

Amoxicillin↗

Ultrastructural study of two patterns in the interaction of Helicobacter pylori with neutrophils.

As evidenced by electron microscopy, unopsonised bacteria of some Helicobacter pylori strains were readily taken into cytoplasmic vacuoles of human neutrophils; those of other strains were only rarely absorbed. The strains engulfed like this also induced strong oxidative burst reactions in neutrophils, as measured by chemiluminescence. This has been associated with peptic ulcer disease, in the past. The ultrastructural interaction patterns agreed with the reaction patterns shown by chemiluminescence.

Bacterial Adhesion↗

Nonopsonic activation of neutrophils and cytotoxin production by Helicobacter pylori: ulcerogenic markers.

Fifty-four clinical isolates of Helicobacter pylori from human gastric biopsy specimens were tested for cytotoxin production, as determined by intracellular vacuolization of HeLa cells, and for the induction of oxidative burst in human polymorphonuclear leukocytes (PMNLs), as measured by luminol-enhanced chemiluminescence (CL). Nonopsonized, 20 of the H. pylori strains induced a rapid and strong CL response, in contrast to 30 other strains, which showed only weak and slow responses. Another four strains gave inconclusive results. Cytotoxin production was demonstrated in 10 of the 20 strains with rapid responses but only in 3 of the 30 strains with slow and low responses (p = 0.0027, Fisher's exact test, two-tailed). Eleven of the 15 cytotoxin-producing strains (p = 0.0135) and 13 of the 20 strains with strong CL responses (p = 0.0209) were from 22 patients with peptic ulcer disease (PUD). The ability of some nonopsonized H. pylori to activate PMNLs showed co-variation with their ability to produce cytotoxin, but these two properties seem to be independent markers of PUD.

Adult↗

Azithromycin resistance in Campylobacter jejuni and Campylobacter coli.

The MICs of erythromycin, azithromycin and ciprofloxacin were determined for 60 human fecal isolates of Campylobacter. Of these, 30 strains selected on the basis of their resistance to erythromycin by disk diffusion were highly resistant to both erythromycin and azithromycin. Nine of these selected isolates were resistant to ciprofloxacin. The remaining 30 strains were non-selected, consecutive isolates of Campylobacter susceptible to erythromycin by disk diffusion and were shown to be two- to five-fold more susceptible to azithromycin than to erythromycin as determined by MIC testing.

Azithromycin↗

Incidence of Helicobacter pylori strains activating neutrophils in patients with peptic ulcer disease.

A total of 61 human gastric isolates of Helicobacter pylori were studied for their ability to induce an oxidative burst in human neutrophils measured by luminol enhanced chemiluminescence. About one third of the strains induced strong and rapid chemiluminescence in neutrophils even without serum opsonins and agglutinated these cells on glass slides within two minutes. For other strains complement was required, although even then the reactions remained at a lower level. The activating and agglutinating property was bound to the cells, heat labile, and sensitive to several enzymes but resistant to acid. Strains possessing such activity were more common in patients with peptic ulcer disease than in patients with active chronic gastritis only (p = 0.0261, Fisher's exact test, two tailed). The activity shown might be a new indicator for ulcerogenic strains and could also partly explain the accumulation of neutrophils in the gastric mucosa during H pylori infection.

Agglutination↗

Evaluation of the E test in testing susceptibility of Pseudomonas aeruginosa to tobramycin.

The E test, a new technique for measuring MICs of antimicrobial agents with the ease of disc diffusion tests, was evaluated in testing the susceptibility of 94 clinical isolates of Pseudomonas aeruginosa to tobramycin. The use of the E test was found acceptable; 93% of the MIC results were within one log2 dilution step and 100% were within two log2 dilution steps when the MICs obtained by the E test were compared to those obtained by the conventional agar dilution method. When the E test was compared to the broth microdilution method the corresponding figures were 84% and 100%, respectively.

Colony Count, Microbial↗

Role of metronidazole resistance in therapy of Helicobacter pylori infections.

Susceptibility to metronidazole was determined by disk diffusion tests for 559 strains of Helicobacter pylori isolated from patients. The overall metronidazole resistance was 26%. In males metronidazole-resistant strains made 18% of all H. pylori strains, and in females the corresponding figure was 40% (P less than 0.001). MICs of metronidazole were determined for H. pylori strains from 86 patients undertaking triple therapy, i.e., treatment with colloidal bismuth subcitrate, amoxicillin, and metronidazole. Of the nonresponders who remained culture positive despite the therapy, 69% had strains with metronidazole MICs of greater than or equal to 32 micrograms/ml before the therapy, and all nonresponders had metronidazole-resistant strains after the therapy. Metronidazole resistance was, however, also found in 27% of responders before therapy. To find whether the MICs of metronidazole for H. pylori strains remained constant for longer periods, consecutive isolates sampled several years apart from the same patients were tested in parallel and no changes in the MICs were found. H. pylori was successfully eradicated by the triple therapy from 91% of patients with metronidazole-susceptible pretreatment strains and from 63% of patients with metronidazole-resistant strains before the therapy (P less than 0.01). Although resistance to metronidazole has a significant role in treatment failures in H. pylori infections, high eradication rates can be achieved with the use of the present triple therapy even in populations with a high overall metronidazole resistance rate.

Adult↗

Triple therapy of Helicobacter pylori infection in peptic ulcer. A 12-month follow-up study of 93 patients.

This study was undertaken to evaluate the success of triple therapy in peptic ulcer patients and ulcer relapses. One hundred and one consecutive Helicobacter pylori-positive peptic ulcer patients were assigned to an open trial with 2 weeks of treatment with colloidal bismuth subcitrate, amoxicillin, and metronidazole. At the 6-week follow-up only 1 duodenal ulcer was unhealed of 57 active ulcers, and H. pylori was found to be eradicated in 84% of the 100 subjects. The sensitivity to metronidazole was determined from 71 pretreatment strains of H. pylori. Eradication of H. pylori succeeded in 89% of the patients with metronidazole-susceptible strains and in 61% of patients with metronidazole-resistant strains (p < 0.03). All 16 patients in whom the treatment failed to eradicate the organism had metronidazole-resistant strains after treatment. The ulcer relapse rate was low. At the 12-month follow-up of 93 patients only 1 of the 84 H. pylori-negative patients (including 4 patients after new successful therapy) had relapsing ulcers (2 asymptomatic episodes), and 1 had H. pylori reinfection, whereas 3 of the 9 bacteria-positive patients relapsed (p = 0.002); at the 2-year control 2 more patients had ulcer relapses. The eradication of H. pylori infection clearly prevents relapses of peptide ulcer, but the success of triple therapy depends on the frequency of pretreatment metronidazole-resistant H. pylori strains.

Administration, Oral↗

Emergence of fluoroquinolone resistance in Campylobacter jejuni and Campylobacter coli in subjects from Finland.

The in vitro susceptibilities of 102 human campylobacter strains isolated between 1978 and 1980 and 100 strains isolated in 1990 to ciprofloxacin, norfloxacin, erythromycin, gentamicin, and doxycycline were examined. The biotypes and heat-stable serotypes of the strains as well as antimicrobial treatments and travel history of the campylobacter-positive patients were also studied. The results indicated that susceptibility to erythromycin, gentamicin, and doxycycline has remained the same during the past 10 years. No gentamicin-resistant strains were found. Resistance to erythromycin was 3% in both groups of strains. However, the number of norfloxacin-resistant strains increased from 4 to 11% in the follow-up period, and ciprofloxacin-resistant strains, which had not occurred 10 years ago, composed 9% of the strains isolated in 1990. Thus, the increase of fluoroquinolone resistance in Campylobacter jejuni and Campylobacter coli has been significant in Finland in the past 10 years.

4-Quinolones↗

Helicobacter pylori and associated gastroduodenal diseases. Review article.

Helicobacter pylori is a microaerophilic, Gram-negative, spiral rod, the role of which in different gastric diseases has been investigated worldwide since the beginning of the 1980s. H. pylori has been shown to be the causative agent in active chronic gastritis, and it is regularly found in patients endoscopied for duodenal ulcer. The bacterium is also frequently isolated from persons with gastric ulcer, gastric carcinoma and non-ulcer dyspepsia. Apart from cultivation of the bacterium, other diagnostic procedures include various staining methods and urease tests of gastric biopsy samples. The application of non-invasive diagnostic methods, serology and urea breath tests, is rapidly increasing. H. pylori is susceptible to several antimicrobials in vitro, but eradication of the bacterium from the gastric mucosa is not always achieved. The best results until now have been obtained with the combined use of bismuth salts and two antibiotics. In active chronic gastritis and duodenal ulcer patients, eradication of the bacteria has resulted in healing of the disease with permanent decrease of circulating antibodies and negative urease tests. H. pylori has been found worldwide and the infection shows an age-dependent increase. Man, apparently, is the reservoir of the bacterium, but the exact mechanisms of interhuman transmission are still not defined.

Duodenal Diseases↗

Waterborne Campylobacter jejuni epidemic in a Finnish hospital for rheumatic diseases.

A waterborne Campylobacter jejuni outbreak in the Rheumatism Foundation Hospital in Heinola, Finland, in November-December 1986 is described. 32 patients and 62 members of the staff developed gastrointestinal symptoms. C. jejuni heat-stable serotype 45 was isolated from the faeces of 32 enteritis patients and from none of the controls. No other enteropathogens were found. Positive serological responses to C. jejuni acid extract antigen were detected by enzyme immunoassay in 34% of the symptomatic hospital patients, in 40% of the symptomatic staff members, and in 10% of the controls. The clinical course of the illness was mostly mild and self-limited. No striking progress in the arthritis symptoms of the patients was found after the outbreak. The hospital has its own water supply. C. jejuni of the same serotype as the epidemic strain was isolated from the water of the pipeline system. After a careful examination some aged components of the waterworks were found to be responsible for leaks that resulted in the contamination of the water.

Adult↗

Waterborne outbreak of Campylobacter enteritis after outdoors infantry drill in Utti, Finland.

Diarrhoea, abdominal pain, malaise and fever affected 75 of the 88 conscript soldiers in Utti, Finland after an outdoors infantry drill. Campylobacter jejuni, heat-stable serotype 3/43/59, was isolated from 37 out of 63 men investigated. A clear serological response was evident in the risk group and negligible in the control group. The entire population at risk was interviewed. The outbreak was associated with the consumption of untreated surface water. C. jejuni, heat-stable serotype 3/43/59, was isolated on two occasions from the water source.

Adult↗