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Biomedical subjects

A M Hirschl

Publications and source records attributed to A M Hirschl.

At least 73 records · Page 4Linked to original sources

In vitro susceptibility of Campylobacter jejuni and Campylobacter coli isolated in Austria to erythromycin and ciprofloxacin.

More than 200 strains of Campylobacter (C.) jejuni/coli isolated in 1985 and 1987/88 from human fecal specimens were tested for their susceptibility to erythromycin and ciprofloxacin. Their MIC90 as assessed by agar dilution tests was 2.0 and 0.5 mg/l, respectively. Thus, all strains were regarded as susceptible to ciprofloxacin. With 2 out of 55 strains of C. coli the MIC of erythromycin was 8.0 mg/l. Therefore, only 3.6% of the C. coli strains were resistant to erythromycin. All 209 strains of C. jejuni proved to be susceptible to erythromycin.

Austria↗

Frequency of occurrence and characterization of catalase negative Campylobacter isolated from human feces in Vienna.

Of a total of 124 Campylobacter (C.) strains isolated 1988 from fecal specimens, 4 (3.2%) were catalase-negative. Two strains were catalase-negative variants of C. jejuni. The other two were identified as C. upsaliensis on the basis of their biochemical properties and of the results of DNA-DNA hybridization with biotinylated probes from C. upsaliensis and C. jejuni. Both had been isolated from patients after their return from Asia (India and Thailand, respectively). In one case, a significant decrease of the antibody titre was observed within 12 months when the patient strain was used as an antigen. Since this patient had been suffering from diarrhoea during her stay and since with the exception of amoebic cysts, no other intestinal pathogen was isolated, C. upsaliensis is thought to have been the reason for the diarrhoeal episode.

Adult↗

Comparison of ELISA antigen preparations alone or in combination for serodiagnosing Helicobacter pylori infections.

The immunoglobulin G antibody response to Helicobacter pylori was assessed in 78 patients with non-ulcer dyspepsia using five different antigen preparations. All patients were endoscoped and biopsied. The H pylori state was determined histologically on at least two endoscopic biopsy specimens using a modified Giemsa stain. The ultracentrifuged cell sonicate, acid glycine extract, and 120 kilodalton protein antigens were specific in diagnosing infection (95-98%), but had only moderate sensitivity (70-84%). By mixing either of the two complex antigens with the 120 kilodalton protein, the sensitivity of the test was increased to 97% without affecting the high specificity. The combination of ultracentrifuged sonicate or acid glycine extract with the 120 kilodalton protein therefore seems to be superior to the individual antigen preparations and is particularly suitable for the serodiagnosis of H pylori infection.

Antibodies, Bacterial↗

Bacterial contamination of dialysate in dialysis-associated endotoxaemia.

Bacteriological investigations and endotoxin (ET) determinations were performed during a routine haemodialysis session for six patients. The glucose free dialysate was prepared with untreated tap water. All patients were dialysed for 5 h. Pseudomonas aeruginosa was regularly isolated in numbers up to 10(7) cfu ml-1 from samples of the dialysate inflow, the dialysate site and the dialysate outflow. ET levels in the plasma of the patients increased continuously during haemodialysis and were always higher in the blood outflow line of the dialyzer than in the blood inflow. Despite the high bacterial counts in the dialysate and the increasing ET levels in the patients plasma neither bacteraemia nor fever was observed. The former is due to the impermeability of the dialyzer membrane for bacteria, the latter is explained by low pyrogenicity of P. aeruginosa endotoxin. Inspection of the dialyzer machines revealed that air-traps and heater-unit for the incoming (untreated) tap water before mixing with the dialysate concentrate were the only sites where high bacterial release was feasible, as this part of the machine escaped disinfection due to the construction of these devices. We recommend the regular disinfection of all parts of a dialyzer machine, including heating units, air traps and valves.

Dialysis Solutions↗

Comparison of different antigen preparations in an evaluation of the immune response to Campylobacter pylori.

This study presents a novel approach to the analysis of protein antigens of Campylobacter pylori for use in serology. Protein fractions of this bacterium were resolved in polyacrylamide gel electrophoresis, eluted from gel strips in an electric field and used for coating of microtiter plates in an ELISA-type assay run with a small set of sera from both infected and non-infected patients. Reactivity and discriminative power of the different fractionated antigens (1-9) and crude antigen preparations (A-C) were compared. Better discrimination was achieved between positive and negative sera with high molecular weight fractionated preparations (antigens 8 and 9) than with low molecular weight fractions. Among the crude antigen preparations, antigens A (sonicated whole cells) and C (ultracentrifugated sonicate) seem to have a better discriminative power than antigen B (acid glycin extract).

Antibodies, Bacterial↗

Effect of chlorhexidine-containing detergent, non-medicated soap or isopropanol and the influence of neutralizer on bacterial pathogenicity.

In handwashing experiments with Salmonella typhimurium the effect of chlorhexidine (CHX) on the pathogenicity of surviving bacteria was assessed with and without a neutralizer in a mouse model of infection. Without neutralizer the LD50 of CHX handwash fluids was raised. Neutralizer in suspensions of untreated bacteria caused a reduction of LD50 up to 1.2 logs. Thus, in contrast to soap or alcohol, CHX without neutralizer exerted a slight 'depathogenizing' action and neutralizer a slight 'pathogenizing' effect in the experimental model used. However, in comparison to the efficiency of handwashing procedures which reduce the number of bacteria available for transfer by at least 3.0 to 4.2 logs, the size of these effects seems to be negligibly small and unpredictable. Therefore, the single most important parameter in assessing the potency of disinfectants remains the reduction of viable counts with time.

1-Propanol↗

Efficacy of coumermycin, ofloxacin and vancomycin against methicillin-resistant Staphylococcus aureus in vitro and in experimental infections of mice.

In vitro, coumermycin (a bis-hydroxicoumarin gyrase inhibitor) proved significantly more active than ofloxacin and vancomycin against 100 strains of methicillin-resistant Staphylococcus aureus (MRSA). The MIC90 was 0.5 microgram/ml, whereas the corresponding figures for the other antimicrobials were 2.0 and 4.0 micrograms/ml. In vivo, an otherwise lethal septicemia, induced by intraperitoneal administration of a MRSA in mice, was "successfully treated" in 50% of the animals (ED50) with the following dosages (microgram/g b. wt.): coumermycin 0.9, ofloxacin 10.8, vancomycin 22.4. The ED50 of coumermycin was significantly (2 p less than 0.01) different from those of the other drugs. Renal infection as produced in mice by transcutaneous inoculation of the same MRSA was treated with either of the antimicrobials at different dosages (single doses of 0.0 or 1.6 or 6.3 or 25.0 micrograms/g b. wt., twice daily) during 6 days. The largest reductions of viable counts in the kidneys at each dosage as compared to the bacterial counts of untreated animals were achieved with coumermycin (3.4 or 5.5 or 7.7 log10). These reductions are significantly (2 p less than 0.01) different from those achieved with the comparable dosages of ofloxacin and vancomycin which were 0.1 or 1.8 or 2.8 and 0.4 or 1.4 or 3.0 log10 respectively. After a single subcutaneous injection of 250 micrograms mean concentrations in serum of mice for coumermycin were 6.2-5.0 micrograms/ml for 8 h, for ofloxacin 2.0-0.5 micrograms/ml for 2 h, and for vancomycin 14.7-2.5 micrograms/ml for 2 h. Coumermycin and ofloxacin could be alternatives to vancomycin in the therapy of human infections due to MRSA.

Aminocoumarins↗

[The antibacterial effect of ciprofloxacin, ofloxacin and norfloxacin in vitro].

MICs of ciprofloxacin (CIP), ofloxacin (OFL) and norfloxacin (NOR) were assessed with a total of 523 strains of 7 species (spp) of enterobacteriaceae, various pseudomonads, methicillin-susceptible and -resistant S. aureus, L. monocytogenes, Legionella species and C. difficile. In addition, the MBCs were assessed with S. aureus and E. coli. With break-points of less than or equal to 0.5 and greater than or equal to 4 mg/l all strains of E. coli, K. oxytoca, P. mirabilis and indole-positive Proteus spp. were susceptible to all 3 antibiotics. Proportions of susceptible strains almost as high were found with E. cloacae, S. marcescens, K. pneumoniae and methicillin-susceptible staphylococci. With Legionella spp. the MICs of CIP and OFL always indicated susceptibility, whereas with NOR only 62% of the strains were inhibited. Pseudomonads, especially others than P. aeruginosa, were only moderately susceptible to CIP and OFL, but never to NOR. Listeria monocytogenes was susceptible to OFL in 96%, to CIP in 56%, but never to NOR. C. difficile was always resistant. The MBC-values either equalled the MICs or surpassed them up to 2 times at maximum indicating a bactericidal mode of action. Despite of slightly lower MICs of CIP in vitro, OFL seems to be comparably effective. NOR is regarded less effective.

Bacteria↗

The efficacy of antimicrobial treatment in Campylobacter pylori-associated gastritis and duodenal ulcer.

The efficacy of various antimicrobial and anti-ulcer agents on the elimination of Campylobacter pylori in duodenal ulcer patients was investigated. Ranitidine, cimetidine, pirenzepine, aluminium phosphate gel as well as combinations of H2-receptor antagonists or pirenzepine + penicillin V, ciprofloxacin, ofloxacin, phenyl-mercuryborate or rifampicin had no influence on C. pylori in vivo. Short term elimination of C. pylori was achieved in 3/15 patients treated with ranitidine + bacampicillin and in 1/5 treated with cimetidine + metronidazole. This elimination was accompanied by a significant reduction of polymorphonuclear infiltration of the antral mucosa. Development of bacterial resistance was observed in patients with additional quinolones, metronidazole and rifampicin but not in patients treated with betalactam antibiotics.

Anti-Bacterial Agents↗

[Campylobacter pylori, gastritis and peptic ulcer].

In the course of routine gastroduodenoscopic examination of 218 patients bioptic mucosal specimens were examined bacteriologically for the presence of Campylobacter (C.) pylori. The organism was isolated from 52 out of 53 patients (98%) with duodenal ulcer, 7 out of 9 with gastric ulcer (78%), 24 out of 31 with mucosal erosions (77%), 10 out of 10 with duodenitis (100%), 16 out of 16 with chronic active gastritis (100%) and from 40 out of 73 patients (55%) with inactive chronic gastritis. By contrast, all specimens from 26 patients with endoscopically and histologically normal mucosa were negative for this bacterium. The rate of elimination of C. pylori from mucosal specimens was investigated as a first step towards studying the influence of antibiotic therapy upon healing of gastric and duodenal ulcers. For this purpose 30 patients with duodenal ulcers were treated either with ranitidine alone (15) or together with bacampicillin (15), which was shown to be highly active in studies with ampicillin in vitro. After 4 weeks the organism was still found in specimens from all patients treated with ranitidine alone, but also in 12 out of 15 patients given combined therapy. This result demonstrates that systemic antimicrobial chemotherapy with bacampicillin is insufficient to eradicate C. pylori from the stomach and the duodenum.

Adult↗

Occurrence, serotypes and biotypes of thermophilic Campylobacters isolated in Vienna.

During the 1982-1986 period of all bacterial pathogens found to have caused diarrhoea, 35% belonged to the genus Campylobacter (C). Approximately 70% of the strains were isolated from persons under the age of 30 years, with a distinct peak of occurrence in the autumn. Biotyping and serotyping according to Lior yielded the following results: C. jejuni biotype I: 32.9%, C. jejuni biotype II: 48.6%, C. coli biotype I: 10.3%, C. coli biotype II: 8.2%. From the 121 strains serotyped, 118 (97.5%) were typable. The serotypes most frequently encountered were type 1 (15.7%), 4 (9.9%), 2 and 11 (7.4% each). There were 2 familial outbreaks of Campylobacter enteritis which could be completely elucidated by biotyping and serotyping. One outbreak was caused by C. jejuni biotype I serotype 11, the other by C. jejuni biotype II serotype 6. Considering the frequent occurrence of Campylobacter infections, isolates should be routinely typed. The existing typing methods and schemes are highly developed.

Age Factors↗

Frequency of occurrence of Campylobacter pylori and analysis of the systemic and local immune response.

During gastroduodenoscopic examination of 225 patients, bioptic mucosal specimens were taken for bacteriological and histological examination (Table 1). Campylobacter (C.) pylori was isolated from 7 out of 9 patients (78%) with gastric ulcer, from 59 out of 60 (98%) with duodenal ulcer, from 24 out of 31 (77%) with gastric erosions, from 10 out of 10 (100%) with duodenitis, from 14 out of 16 (88%) with chronic active gastritis, from 40 out of 73 (55%) with chronic inactive gastritis and from none out of 26 patients (0%) with normal mucosa (Table 2). To study the immune response an ELISA was developed which proved to give well reproducible and specific test results (Fig. 1). IgA- and IgG-titres were strongly reduced after absorption with C. pylori, but not with other antigens (including C. jejuni and C. coli, Table 3). Some sera gave reactions at higher titres when tested with the patient's own strain than with the standard antigen which is a mixture of 4 strains (Table 4). This indicates differences of the antigen composition within the species C. pylori. Sera from patients with positive culture showed higher IgG- and IgA-titres than sera from patients without isolation of C. pylori. The IgM-titres, however, were comparable in both groups (Fig. 3). Partially, sera from patients without C. pylori also showed high IgG-titres which were positively correlated with the patient's age. About 60% of culturally positive patients had specific IgA in their gastric juice, whereas this was not so with patients without isolation of C. pylori (Fig. 6). Examination of sera from healthy children and blood donors revealed that IgG but not IgA or IgM rose significantly with increasing age (Figs. 7-9). As can be concluded from the results of cultural and serological tests, C. pylori seems to be responsible at least for a part of cases of gastritis and peptic ulcer.

Adult↗

Infections following tickbites. Tick-borne encephalitis and Lyme borreliosis--a prospective epidemiological study from Tyrol.

We present here a prospective study on infections following tickbites in military recruits in the province of Tyrol (Austria). 84 recruits experienced tickbites and underwent clinical and serological examination twice at four-week intervals for signs of tick borne encephalitis (TBE)-virus or Borrelia burgdorferi infections. 56 and 50 recruits could be evaluated for TBE-virus and Borrelia infection, respectively. Whereas no recruit was found with clinical or laboratory evidence of TBE-virus infection, two (4%) recruits showed an erythema chronicum migrans as primary manifestation of a Borrelia burgdorferi infection and 11 (20%) recruits had a significant increase in the titer of anti-Borrelia burgdorferi antibodies. Our results support the predominance of a subclinical course of a tick-transmitted borrelia infection in the population under observation, and shed some light on the epidemiological situation of tick-transmitted diseases in Tyrol.

Animals↗

Infant tuberculosis in Austria--trend reversal since 1990?

Since 1990 a relatively high number of cases of childhood tuberculosis has been observed in Austria, mainly occurring in the age-group of 0-4 years. Within this group most cases were registered in 1995. Since the beginning of 1995 the establishment of a lab-supported nationwide data collection system enables a more detailed recording of the cases diagnosed. Out of the 85 cases with infant tuberculosis registered in 1995 and 1996, 66 were diagnosed with pulmonary manifestation. In 45 cases tuberculosis was proven by culture. In nine (20%) of these cases the most likely route of infection has appeared to be direct transmission from an adult in the same household suffering from culture proven tuberculosis in the same year. For three of the cases the DNA of the isolated Mycobacterium tuberculosis strains from the adult and the infant was typed using RFLP analysis. In each case identical strains could be demonstrated.

Austria↗

[Incidence of increased serum Helicobacter pylori IgG antibodies in children with and without chronic abdominal pain].

The prevalence of Helicobacter pylori (HP) IgG antibodies was analysed in a group of 142 asymptomatic children (group A) and in 31 pediatric patients (group B) with recurrent abdominal pain. HP IgG antibodies were measured by a commercially available fluorescence-enzyme immuno-assay test (Heloritest IgG, Fa Eurospital). In asymptomatic children the prevalence of HP IgG antibodies increased significantly with age from 17% with 6 years to more then 40% with 14 years. A higher prevalence of HP IgG antibodies was found in children living in more crowded housing conditions. Comparing the number of HP IgG positive children in group B (58%) to a matched population from group A (35%) no statistically different prevalence rates were found. Thus HP IgG antibodies are found in similar frequencies, in both, symptomatic and asymptomatic children. Therefore the presence of HP-IgG antibodies does not necessarily indicate that the HP infection is the cause for the recurrent abdominal pain in these children.

Abdominal Pain↗