Biomedical subjects

F Allerberger

Publications and source records attributed to F Allerberger.

135 records · Page 8Linked to original sources

PubMedDate not supplied

Campylobacter bacteremia: clinical experience with three different blood culture systems at Mayo Clinic 1984-1990.

The efficiency of three commercially available blood culture systems for isolating Campylobacter sp. was investigated. Thirteen of 189,688 blood cultures from patients seen at the Mayo Clinic from 1984 through 1990 were positive for Campylobacter sp. Eleven out of 13 blood cultures positive for Campylobacter sp. were part of a complete three bottle set of cultures (Isolator from Du Pont, Roche Septi-Chek from Hoffman-La Roche, and non-vented Tryptic Soy Broth from Difco), none of them providing a specific microaerophilic mileu. The aerobic Roche Septi-Chek seems to be more efficient for the detection of Campylobacter sp. in blood cultures than either the anaerobic Tryptic Soy Broth (Difco) or the Isolator (Du Pont) using the incubator condition of 5% CO2.

Aged↗

PubMedDate not supplied

Enterohemorrhagic Escherichia coli (EHEC) in pediatric hemolytic-uremic syndrome: a prospective study in Germany and Austria.

Studies from Europe indicate that infections with enterohemorrhagic Escherichia coli (EHEC) non-O157:H7 strains are increasing in frequency as a cause of hemolytic-uremic syndrome (HUS). In 1997 a prospective study was performed in Germany and Austria to assess the distribution of EHEC serotypes, to characterize the clinical course and to examine environmental aspects. 95 children with a diagnosis of HUS were evaluated in Germany and Austria. Diarrhea, which was bloody in 67%, was reported in 97% of patients. Oligo-/anuria occurred in 76% of patients, of which 63% required dialysis. Two patients showed neurological sequelae at the 2-month follow-up, both of them were infected with non-O157:H7 serotypes. Case fatality in the acute stage was 3/95, in two of these patients EHEC was isolated. Stool and serum specimens were analyzed for the presence of EHEC and antibodies against O157 lipopolysaccharide (LPS). Serotype O157:H7 was identified in 36/58 (62%) isolates, 22 strains (38%) belonged to non-O157:H7. Combining stool culture with serology, EHEC infection was documented in 88% of patients, including three patients without diarrhea. Non-O157:H7 serotypes occurred in 77% of children up to 36 months of age and were the most prevalent serotype in children up to 12 months of age.

Antibodies, Bacterial↗

PubMedDate not supplied

In vitro susceptibility of Candida albicans, Austria 1992.

A total of 38 isolates of Candida albicans were collected from clinical specimens and tested for minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of amphotericin B, flucytosine and fluconazole. For amphotericin B and flucytosine all patients had isolates with MICs < or = 2 micrograms ml-1 and < or = 8 micrograms ml-1 respectively. For fluconazole all but two isolates had MICs < or = 16 micrograms ml-1. In vitro susceptibility testing remains problematic since standardized methods have not been established and the susceptibility and resistance ranges of MIC/MFC values still have to be defined in relation to in vivo data. Nevertheless, these results indicate that topical application of amphotericin B (more than 1 kg of amphotericin B per year at an intensive care unit performing selective digestive tract decontamination on certain trauma patients) had no major impact on the resistance patterns of C. albicans. In contrast, in this study both fluconazole-resistant isolates were from AIDS patients who were known to have received fluconazole therapy. Treatment with fluconazole--quite common in patients with AIDS--may produce resistant fungal isolates.

Amphotericin B↗

PubMedDate not supplied

Antibacterial activity of peritoneal exudate in patients treated with 2 g cefotiam for surgical anti-microbial prophylaxis.

The objective of this study was to investigate the presence of antibacterial activity in peritoneal exudate (PE) of patients treated with cefotiam (CFT). CFT (2 g) was administered as a 'single-shot' antimicrobial prophylaxis to 6 patients at the beginning of colorectal resection. Samples of PE were collected from each patient on days 1, 2 and 3 after surgery. CFT was detectable in the samples of day 1 for 5 of the 6 patients. The influence of PE on antibacterial activity of the antimicrobial drug was evaluated carrying out the MICs of CFT against Escherichia coli K-12, E. coli (ATCC 10798), Klebsiella pneumoniae (ATCC 1003), Proteus rettgeri (Sanelli) and Staphylococcus aureus (ATCC 29213) with and without the addition of PE. The presence of PE enhanced the antimicrobial activity of CFT against gram-negative strains, but not against S. aureus (ATCC 29213). These results suggest the presence of substances in PE that possess endogenous antibacterial activity. Thus, antimicrobial activity in PE cannot be predicted by evaluating pathogen sensitivity in vitro only.

Antibiotic Prophylaxis↗

PubMedDate not supplied

In vitro experiments on catheter-related infections due to gram-negative rods.

Although many complications may arise with the use of central venous catheters, catheter-related bacteremia is considered to be the most serious complication. Microflora on the patient's skin (coagulase-negative staphylococci, Staphylococcus aureus) is thought to represent the major source of microorganisms causing catheter-related infections. Gram-negative rods are increasingly observed as causative agents. We therefore performed an in vitro study to elucidate the pathogenesis of polymer-associated infections caused by enterobacteriaceae and nonfermenters and to study the resistance of polymer surface-grown gram-negative rods against antibiotics. Using a modification of the semiquantitative method for culturing vascular cannulas on solid media described by Maki et al., we studied the adherence of various gram-negative rods to 1-cm segments of silastic catheters, a material used for Port-A-Cath-systems. Organisms were obtained from the American Type Culture Collection (Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, Enterobacter cloacae). All organisms but Klebsiella showed extensive irreversible adherence. Production of an extracellular slime substance was observed only with antimicrobially treated Pseudomonas. After 'infection', the silastic catheter segments were treated with various antimicrobial agents. The following antibiotics were used either individually or in combination: cefotaxime, ciprofloxacin, imipenem, fosfomycin and gentamicin. Despite the fact that the antibiotic concentrations used were many times greater than the respective MICs of the various antibiotics, none of the antibiotics tested succeeded in eliminating the organisms. E. coli was found to be the most susceptible organism. These in vitro data substantiate our clinical impression that it is hardly possible to successfully eliminate the colonization of central venous catheters with gram-negative rods by using the antimicrobial agents employed here.

Anti-Bacterial Agents↗

PubMedDate not supplied

In vitro susceptibility of Listeria monocytogenes: comparison of the E test with the agar dilution test.

In vitro susceptibility testing was performed on 66 strains of Listeria monocytogenes. Recently obtained clinical isolates from Austria, France, Norway and Switzerland and 17 reference strains from three type culture collections were tested against ampicillin, gentamicin, trimethoprim-sulfamethoxazole, ampicillin-sulbactam, meropenem, and first-, second-, third- and fourth-generation cephalosporins. All isolates were susceptible to ampicillin, gentamicin, and trimethoprim-sulfamethoxazole, ampicillin-sulbactam, and meropenem and more than 86% of the minimal inhibitory concentration E test values were within plus/minus one dilution step of the agar dilution test. In vitro susceptibility of L. monocytogenes has not changed markedly during the last decades; the level of susceptibility of old reference strains did not differ from that of recently encountered clinical isolates. The E test seems to be a suitable method for Listeria.

Anti-Bacterial Agents↗

PubMedDate not supplied

[Lyophilized cartilage--an antibiotic carrier].

Human lyophilized bruised costal cartilage was tested in vitro for its ability to act as a carrier medium for antibiotics. A remarkable capacity of accumulating streptomycin, gentamicin, tobramycin, vancomycin and ciprofloxacin was observed; whereas beta-lactum antibiotics and fosfomycin were released at a high rate. This release pattern was not influenced by the sterilization procedure, but rather by the size of the cartilage granula. Lyophilized cartilage--rehydrated in antibiotic-solutions--be helpful adjunct in the surgical management of osseous infections.

Anti-Bacterial Agents↗

PubMedDate not supplied

[Effect of Listeria on contractibility of human uterine muscle].

In Austria the prevalence of listeriosis is 2.6 cases per million inhabitants yearly, hence rather rarely the cause of spontaneous abortion or premature birth. On the other hand, Listeria monocytogenes is found in 1% of the asymptomatic population as a component of stool flora. Since the cause of premature labour contractions remains unclear in about half of all cases, we examined 29 listeria strains for their ability to cause myometrial contraction by direct contact using an in-vitro uterine strip-model. Seven of nine L. monocytogenes strains were able to cause contractions; contractions were not inducible by an nonhaemolytic mutane (SLCC 53, avirulent) nor by a rough strain (SLCC 5779, only slightly virulent). Three of six L. ivanovii isolates also exhibited the ability to induce contractions. None of the apathogenic species (L. innocua, L. seeligeri, L. welshimeri, L. grayi and L. murrayi) was capable of activating contractions in our in-vitro model. Only L. monocytogenes and L. ivanovii cause conjunctivitis after being dropped in rabbit's eyes (positive Anton Test). The influence of listeria on uterine activity as found in our in-vitro model thus correlates with the classical pathogenicity test. We consider these in-vitro results as an additional argument to oppose the presence of L. monocytogenes in ready-to-eat foods.

Adult↗

PubMedDate not supplied

Detection of Helicobacter pylori infection using single serum specimens: comparison of five commercial serological tests.

BACKGROUND/AIMS: Various commercial kits have been developed for serological diagnosis of Helicobacter pylori infection, but data on their diagnostic accuracy and direct comparisons between the tests are often lacking. We evaluated the sensitivity, specificity and relative agreement of three assay kits which have not been evaluated in published studies so far. MATERIAL AND METHODS: We examined a self-contained card-based enzyme immunoassay (ImmunoCardR H. pylori IgG; Meridian Diagnostics, Milano, Italy), a microwell-based enzyme immunoassay (Enzygnost Anti-Helicobacter pylori/IgG; Behringwerke, Marburg, Germany), and an indirect immunofluorescence test (Immunfluoreszenz IgG Test; Bios, Graefelfing, Germany). We also examined a latex agglutination test (PylorisetR Dry; Orion Diagnostica, Espoo, Finland) and a complement fixation test (CFT H. pylori; Institute Virion, Rueschlikon, Switzerland) which have been evaluated by others previously. Sera originated from 110 patients, sent to the outpatient clinic of a large tertiary hospital for gastrointestinal endoscopy. RESULTS: We found that the latex agglutination test, card-based enzyme immunoassay, and microwell-based enzyme immunoassay had overall sensitivities of 74.4%, 95.4%, and 90.7%, and specificities of 94%, 76.1%, and 79.1% respectively. Indirect immunofluorescence test and complement fixation test yielded sensitivities/specificities of 62.8%/86.6%, and 74.4%/77.6%, respectively, when compared with gastric biopsy findings. Combining two tests did not increase the diagnostic yield. The relative agreement of the latex test, card-based enzyme immunoassay, microwell-based immunoassay, immunofluorescence test, and complement fixation test was 86.4%, 83.6%, 83.6%, 77.3%, and 76.4%, respectively. CONCLUSIONS: We conclude that for serology based on single serum specimens the enzyme immunoassays and the commercial latex test represent helpful noninvasive tools for the diagnosis of Helicobacter pylori infection. Complement fixation test and IIFT might be more suitable for serological tests on multiple serum specimens, e.g. monitoring the effect of antimicrobial eradication therapy.

Adult↗