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Biomedical subjects

F Allerberger

Publications and source records attributed to F Allerberger.

At least 73 records · Page 4Linked to original sources
PubMed1998

Dynabeads plus 3 M Petrifilm HEC versus Vitek Immunodiagnostic Assay System for detection of E. coli O157 in minced meat.

The potentially low infective dose of Escherichia coli O157 makes it necessary to be able to detect low numbers in food, and the lack of sensitivity of direct plating has led to the development of various enrichment and detection methods. Until now, the most selective procedure for detection of E. coli O157 isolates was the immunomagnetic separation (IMS) method. The number of sorbitol non-fermenting micro-organisms other than E. coli O157 that adhere non-specifically to the magnetic beads hampers the application of IMS. The use of IMS in conjunction with 3 M Petrifilm-HEC yielded EHEC O157 in 21 of 165 samples of minced meat (12.7%). Without advance application of IMS, Petrifilm plates often yield confluent growth and colonies too numerous to count. The Vitek Immunodiagnostic Assay System (VIDAS-ECO) showed good sensitivity when testing artificially contaminated beef samples, but only four of 21 naturally contaminated samples were recognized. The addition of 3 M Petrifilm to IMS resulted in less growth of contaminants and eliminated much of the need to test presumed colonies for confirmation. The combination of IMS and 3 M Petrifilm-HEC is a fast and efficient screening procedure for E. coli O157 in minced meat.

Animals↗
PubMed1998

Evaluation of four methods for detection of Clostridium difficile or C. difficile toxin: cytotoxin assay, culture, latex agglutination, and a new rapid immunoassay (C. difficile toxin A test).

The performance of C. difficile toxin A test (Oxoid, Basingstoke, UK), an immunoassay for the detection of C. difficile toxin A in fecal samples, for the diagnosis of C. difficile-associated diarrhea was compared with those of cytotoxin assay, culture, and a latex agglutination assay (Culturette Brand CDT Rapid Clostridium difficile test; Becton Dickinson, Cockeysville, MD). A total of 105 stool specimens from 71 patients were tested. Of the 105 specimens analyzed, 6 (5.7%) samples were positive by all four methods, 66 samples (62.9%) were concordant negative. Two patients fulfilled all clinical criteria for C. difficile-associated diarrhea but had negative results in the cytotoxicity tests. The sensitivity and specificity, as determined against cytotoxin assay results, were, respectively 52.4% and 93.9% for latex agglutination, 68.2% and 84.3% for rapid immunoassay and 36.4% and 92.8% for culture. No single laboratory test yields a definitive diagnosis of C. difficile-associated diarrhea at present. Test results by any of these methods must be used in conjunction with patient history when making the diagnosis to avoid indiscriminate treatment of individuals without disease or the lack of treatment for individuals with a serious infection. We consider the rapid and easy-to-perform C. difficile toxin A test not to be an essential adjunct for the diagnosis of C. difficile-associated diarrhea.

Adolescent↗
PubMed1998

E-test for susceptibility testing of Mycobacterium tuberculosis.

SETTING: Initial isolates should be tested for drug susceptibility to confirm the anticipated effectiveness of chemotherapy. OBJECTIVE: To evaluate E-test strips for susceptibility testing of Mycobacterium tuberculosis. DESIGN: A proportion method using Lowenstein-Jensen medium and the Bactec radiometric system were compared with the E-test (isoniazid [INH], rifampicin [RMP], ethambutol [EMB] and streptomycin [SM]). RESULTS: For 73 of the 81 M. tuberculosis isolates (90.1%) the proportion and E-test methods yielded concordant susceptibility results against all four antimicrobial agents tested. Of these 73 strains, 69 were fully susceptible; the four isolates showing resistance to antimicrobial drugs by both methods were also resistant when tested by Bactec 460TB. While the proportion method indicated susceptibility for the eight remaining strains, E-test results showed mono EMB resistance in five strains, INH resistance for two isolates (including one isolate resistant to EMB plus INH), and for one strain E-test yielded resistance to EMB and SM. Using Bactec as the reference method, the E-test resulted in false resistance in eight strains and no false susceptibility. CONCLUSION: Due to a substantial rate of false resistance, this method cannot be recommended at present for practical use in clinical laboratories.

False Negative Reactions↗
PubMed1997

[Enterohemorrhagic Escherichia coli and hemolytic-uremic syndrome].

Enterohemorrhagic Escherichia coli (EHEC) are increasingly identified as the cause of diarrhea and hemorrhagic colitis in countries with highly developed livestock. In 5-10% of patients, full-blown hemolytic uremic syndrome (HUS) occurs as a postinfectious life-threatening complication. Up to 1996, 5 out of 39 patients (12.8%) with EHEC O157 infections in Austria developed HUS. Acute complications of HUS such as brain edema may also lead to death; one fatal outcome has been observed so far in Austrian patients. Aside from the cytotoxic Shiga toxins, other different pathogenic factors are often found in clinical EHEC isolates. These include a cytolysin termed EHEC-hemolysin and a low molecular heat-stabile enterotoxin. Furthermore, most EHEC strains express an important surface protein, intimin, which is important for adherence to intestinal epithelial cells. EHEC are heterogeneous in their antigenic structure (O-, H-antigens). In Austria O157:H7 and O157:H- are the dominating serogroups; in 1997 the first Austrian case of HUS due to EHEC O26:H11 was documented. Because there are no known reliable phenotypical markers for EHEC, diagnostic strategies should focus on the demonstration of Shiga toxins or Shiga toxin genes. For epidemiological purposes it is also important to attempt to isolate the causative agent. Cows and other ruminants are reservoirs for EHEC. In the Tyrol 3% of unpasteurised milk samples, up to 10% of minced beef samples, and 6% of calves yield EHEC O157. Aside from transmission via contaminated food, direct transmission from person to person also plays a major role in the chain of EHEC infection. In contrast to Italy and Bavaria, Austria has not experienced a major outbreak due to this organism so far. A nationwide surveillance system of HUS has shown an incidence of 0.37 HUS cases per 100,000 residents in the age group 0-14 years for 1995 (Italy: 0.2 cases per 100,000; Bavaria: approx. 1.5 cases per 100,000).

Animals↗
PubMed1997

[Vancomycin resistant enterococci in Austria].

This study reports pheno- and genotypical analysis of 9 isolates of vancomycin-resistant enterococci (VRE) and 5 vancomycin-sensitive enterococci (VSE) in Austria: 5 E, faecium isolates of 4 patients (the sole patients demonstrating VRE at the University Hospital of Innsbruck in 1994 and 1995), 3 glycopeptide-sensitive isolates collected in Innsbruck in February 1996 for epidemiological analysis, and 6 enterococcus isolates from the University Hospitals of Vienna and Graz. The pheno- and genotypical analyses of all glycopeptide highly resistant E. faecium and E. faecalis isolates indicated the presence of VanA type resistance. One E. casseliflavus strain with intrinsic VanC-1 resistance showed a characteristic constitutive low-level resistance to vancomycin and susceptibility to teicoplanin. Genotyping with macro-restriction analysis demonstrated that 3 VRE isolates of the 5 E. faecium specimens were identical; the same applied to 2 VSE isolates. The two patients with VRE had been cared for at the same time in a surgical ICU and likewise, the two patients with VSE were simultaneously treated at a neurological ICU. The genotyping of E. faecalis strains showed that two strains of the three VRE isolates exhibited identical patterns. Epidemiological investigation did not reveal a mode of transmission for this cluster. Two of the 8 patients with VRE died within 60 days after isolation of the bacteria; the doctors in charge did not consider that the enterococci had been the cause of death. The results of our study indicate that oral vancomycin administration to humans is a primary cause of VRE in Austrian hospitals. In Austria approximately 66 kg vancomycin, 20% of it given orally, are administered to patients per year. Approx. 18-20 tons Avotan (active ingredient Avoparcin-10%)/year were used in Austria; as of April 1, 1997 the use of this animal foodstuff supplement is prohibited by the European Commission.

Administration, Oral↗
PubMed1997

Alveolar echinococcosis of the liver in a six-year-old girl with acquired immunodeficiency syndrome.

A 6-year-old girl with acquired immunodeficiency syndrome (AIDS) had extensive alveolar echinococcosis. Diagnosis was proved by needle biopsy of a specimen from affected liver tissue. The case was characterized by the unusually young age of the patient and more specifically by the absence of any detectable parasite-specific humoral and cellular immune response at diagnosis or later. Thus the present case indicates that a marked immunodeficiency caused by AIDS may substantially contribute to the rapid proliferation and early manifestation of the disease. In patients with pediatric AIDS and living in areas endemic for Echinococcus multilocularis, alveolar echinococcosis should be considered in intrahepatic tumor-like lesions even if the result of immunodiagnostic testing is negative.

AIDS-Related Opportunistic Infections↗
PubMed1997

Typing of Austrian Listeria monocytogenes isolates by automated laser fluorescence analysis of randomly amplified polymorphic DNA.

We used automated laser fluorescence analysis of randomly amplified polymorphic DNA (RAPD-Alfa) to study the epidemiology of listeriosis in western Austria. There were no discrepancies between RAPD-Alfa patterns and serotypes found in 18 food isolates and 18 clinical isolates. The results of our study suggest that the food isolates typed were not at the origin of the human cases in western Austria. Using RAPD-Alfa, it was possible to link 9 out of 16 "sporadic" Listeria infections (mother-child cases counted as one) to the occurrence of other cases. Our results underline the necessity of epidemiological clarification of listeriosis cases as a prerequisite for specific preventive measures by public health services (e.g. confiscation of contaminated food products, issue of public warnings). To establish the chain of infection, more is needed than just speciation of bacteria in incriminated food products. Automated laser fluorescence analysis of randomly amplified polymorphic DNA seems a suitable, easy and rapid method for the typing of Listeria monocytogenes strains.

Adult↗
PubMed1997

Cryptosporidiosis after CD34-selected autologous peripheral blood stem cell transplantation (PBSCT). Treatment with paromomycin, azithromycin and recombinant human interleukin-2.

We report two cases of cryptosporidiosis after CD34-selected PBSCT for lymphoma. While the first patient died of pulmonary cryptosporidiosis, treatment with paromomycin, azithromycin and subcutaneous low-dose rhIL-2 to improve numerical and functional T lymphocyte defects completely eliminated infection in the second patient. We conclude, that the removal of mature T lymphocytes by positive selection of CD34+ cells bears the risk of a delayed immune reconstitution resulting in an increased incidence of severe and sometimes fatal opportunistic infections. IL-2 might be useful in this situation by accelerating immune reconstitution and reducing the danger of opportunistic infections.

Adult↗
PubMed1997

Nonhemolytic strains of Listeria monocytogenes detected in milk products using VIDAS immunoassay kit.

In December 1995 detection of Listeria monocytogenes Sv 1/2a in milk products that were routinely sampled for investigation at the Austrian Federal Food Inspection Laboratory (Vienna) led the food manufacturer in question to withdraw his product from the market. While one of seven Listeria strains isolated from this food product using "VIDAS L. monocytogenes kit" was undoubtedly L. monocyotogenes, six strains were nonhemolytic. In classical bacteriology haemolysin is used as an important phenotypic property to differentiate L. monocytogenes from the apathogenic L. innocua species. Species identification by PCR and by Western blotting confirmed that all nonhemolytic strains were indeed L. monocytogenes. Our confirmation of nonhemolytic isolates as true L. monocytogenes strains underlines the considerable potential of the VIDAS system as a specific immunological easy-to-use and automated test kit for detection of L. monocytogenes in food products. Whether or not the presence of non-hemolytic Listeria monocytogenes in food products justifies legal actions should be addressed by the proper authorities.

Austria↗
PubMed1996

Prevalence and clinical manifestations of Shiga toxin-producing Escherichia coli infections in Austrian children.

The prevalence and clinical manifestations of infections associated with Shiga toxin-producing Escherichia coli (STEC) among Austrian children were assessed. Stool samples from 280 pediatric patients were analyzed by enzyme immunoassay (EIA) for the presence of free fecal Shiga toxin (Stx) 1 and 2, and by culture on sorbitol MacConkey agar. Specimens testing positive by the EIA were subjected to a cytotoxicity assay, polymerase chain reaction analysis, and a colony hybridization test. Direct culture on MacConkey agar demonstrated the presence of three Escherichia coli O157:H7-positive stools. These were also positive by EIA and by the DNA-based methods. An additional six samples were positive by EIA, and in four of these, non-O157 STEC of serotypes O111H-, O146:H-, and O113:H53 could be isolated. Analysis of stools for a variety of enteric pathogens demonstrated that STEC was the third most common bacterial pathogen. The clinical manifestations of STEC infections were difficult to distinguish from those of infections caused by other enteric pathogens, as most patients presented with watery diarrhea. The median age of children with STEC infections was 27.6 months (range, 7 months to 5.75 years); children with Salmonella or Campylobacter infections were younger on average, while those with Rotavirus infections were older. This study demonstrated that although Escherichia coli O157:H7 could be identified with the same sensitivity by both EIA or agar-based methods, the identification of non-O157 STEC strains was enhanced by the use of EIA followed by colony hybridization. Analysis of overnight cultures from 53 STEC isolates revealed that all strains producing Stx1, Stx2, or Stx2c reacted in the EIA. However, culture supernatants from Stx2e-producing Escherichia coli O101 were negative in the EIA. Despite this disadvantage, the EIA is easy to perform and time efficient and can be recommended as a screening test for non-O157 STEC in children with diarrhea.

Age Factors↗
PubMed1996

Minimal chronic inactive gastritis: indicator of pre-existing helicobacter pylori gastritis?

Minimal chronic inactive gastritis is regularly observed in routine histopathology. Presently, it is not clear whether this type of gastritis should be regarded as a histopathological entity or a normal variant. The similarity to lesions observed after H.pylori eradication prompted us to look for an association between minimal chronic inactive gastritis and status post H.pylori eradication. In a prospective study of 110 consecutive patients undergoing upper gastrointestinal endoscopy, at least two mucosal biopsies were taken from the gastric antrum and body. Gastritis was classified according to the Sydney System. Antibodies to H.pylori were determined serologically by immunofluorescence test, ELISA, and complement binding reaction. A status post eradication of H.pylori was revealed by medical history and/or positive serology; H.pylori gastritis was found in 39.1%, reactive gastritis in 12.7%, and minimal chronic inactive gastritis in 29.1%. In 19.1% a combination of reactive/ minimal chronic gastritis was diagnosed according to morphology. Status post eradication was observed significantly more often in cases with minimal chronic inactive gastritis (43.8%) than in cases with reactive gastritis (7.1%, p < 0.004). Furthermore, positive ELISA and/or status after eradication was found in 50% of the cases with minimal chronic inactive gastritis (p < 0.005 vs reactive gastritis), in 42.9% of the cases with mixed reactive/chronic inactive gastritis (p < 0.03 vs reactive gastritis), and in 7.1% of the cases with reactive gastritis. Lymphoid aggregates, considered another sign of former H.pylori presence, were found significantly more often in minimal chronic inactive gastritis than in reactive gastritis (50% versus 7.1%, p < 0.005). Minimal chronic inactive gastritis is significantly associated with both positive H.pylori serology and status post eradication and is, therefore, an indicator of pre-existing H.pylori gastritis.

Biomarkers↗
PubMed1996

[Mycotic aortic aneurysm after appendectomy].

Mycotic aneurysms are a rare complication of septic diseases. Frequently they are recognized only in an advanced stage, with resulting poor prognosis. This case report describes a perforated mycotic abdominal aortic aneurysm following appendectomy. Bacterial culture revealed the presence of streptococcus zooepidemicus, an unusual finding in humans.

Aged↗
PubMed1996

[Cryptosporidia associated gastroenteritis: epidemiologic study of children in Tyrol and Vorarlberg].

Stool samples from 523 children aged between 3 months and 6 years were examined for Cryptosporidium parvum by means of the direct immunofluorescence technique in March 1996. The specimens were sent to the Federal Public Health Laboratory in Innsbruck from general practitioners and pediatricians and from hospitals in Tyrol and Vorarlberg. The study was performed during the cold season in an area that does not employ surface water for the production of drinking water. Oocysts of cryptosporidia were detected as the sole agent in 4 out of 294 samples (1.4%) taken from children suffering from diarrheal disease, as well as in 1 out of 229 samples (0.4%) of children in the control group. Duration of diarrheal disease varied from 2 days to 4 weeks. In addition, a 75 stool samples from Tyrolean calves were examined for cryptosporidia. Oocysts were detected in 3 out of 75 stool samples (4.0%). Routine examinations for Cryptosporidium parvum in stool specimens of immunocompetent children with diarrhea do not seem to be necessary in Western Austria during the cold season due to the self-limiting course of the infection.

Animals↗