Spectrum and antibiotic resistance of uropathogens from hospitalised patients with urinary tract infections: 1994-2005.

From 1994-2005, all uropathogens cultured from the urine of hospitalised urological patients were identified and their sensitivity was tested against the most important antibiotics for the treatment of urinary tract infection (UTI). Duplicate isolates were eliminated. The following results were obtained: (i) there was no general trend of increase in resistance; (ii) certain uropathogens developed resistance to some antibiotics; (iii) vancomycin- or linezolid-resistant staphylococci or enterococci did not play a role; (iv) the lowest overall rates of resistance were found with piperacillin/tazobactam; and (v) ciprofloxacin and trimethoprim/sulfamethoxazole showed the next favourable overall activity. Adequate initial antibiotic therapy is critical in the treatment of severe UTI. Therefore, ongoing surveillance of antibiotic resistance must be performed in every institution. Additionally, it reflects antibiotic and hospital infection policies in a defined department or institution.

Implementation of an interactive computer-assisted infection monitoring program at the bedside.

A new computer-assisted infection monitoring (CAI) software program has been developed for use in an intensive-care unit (ICU). By means of an interactive dialogue with physicians at the bedside, infection diagnoses and therapeutic decisions were recorded prospectively during a 3-month test period. By linking epidemiological data with information about therapeutic decisions, CAI could assess the quality of the therapeutic decisions. Antibiotics chosen empirically before the availability of any culture results, matched the antibiotic susceptibility patterns of the subsequently identified pathogens in 74% of the cases. Therapy chosen in collaboration with the computer after the pathogen was known, but before sensitivity results were available, corresponded with the eventual antibiograms of the microorganisms in 90% of the cases. Data analysis by CAI allowed us to assess critically the diagnostic and therapeutic habits in our ICU. Using the query-by-example method, CAI automatically calculated device-associated infection rates.

Antibody response to somatic antigen of Salmonella typhi in areas endemic and non-endemic for typhoid fever.

In sera obtained between the 6th and the 30th day from 16 Austrian and 26 Hong Kong patients with culturally verified typhoid fever, agglutinating antibodies (microagglutination test) at significant titers were detected in 93% of the Austrian (median titer: 640) but in only 50% of the Hong Kong patients (median titer: 240). Similar results (93% and 54% positive sera respectively) were obtained for specific IgM as assessed by the enzyme-linked immunosorbent assay (ELISA) using lipopolysaccharide of S. typhi as antigen (median relative titer: 0.32 and 0.21 respectively). In contrast, specific IgG at significant concentrations were found in only 69% of the Austrian (median relative titer: 0.16) but 88% of the Hong Kong sera (median relative titer: 0.71). The (IgM-detecting) microagglutination test may be sufficiently diagnostic for typhoid fever in nonendemic areas such as Austria. In endemic regions like Hong Kong, however, tests indicative for early specific IgG are indispensable for serological diagnosis of the disease. The ELISA proved useful and is an example for such tests.

[Comparison of the ELISA (lipopolysaccharide) and Widal reactions (O antigen) in the diagnosis of Salmonella infections]. / Vergleich von ELISA (Lipopolysaccharid) und Widal-Reaktion (O-Antigen) in der Diagnose von Salmonellen-Infektionen.

At various times after the onset of disease 50 sera of patients with bacteriologically proven salmonella infections were investigated for O-antigen specific antibodies in ELISA and Widal-tests. 21 of these sera were derived from patients with typhoid fever, 10 from patients with gastroenteritis due to various species of salmonella group D and 19 from patients with group B salmonella-gastroenteritis. Additional 44 sera stemming from patients without such infection were included in the investigation as a control. With ELISA the sera were examined for antibodies of the IgM- and IgG-class separately. As antigens lipopolysaccharide W-preparations from S. typhi ("group D-antigen") and S. typhimurium ("group B-antigen") were used in the ELISA. High reciprocal titers (geometric means: 1404, 2560, and 1020) of IgM were demonstrable in sera drawn 11-30 days after onset of the disease with group D- and group B-antigen respectively (Fig. 1, Table 1 and Table 2). With increasing distance of time from the onset of the disease these titers decreased rapidly. The titers of agglutinating antibodies as measured in the Widal-test behaved similarly to those of IgM (Fig. 1, Table 1 and 2), and the correlation between both was high (r = +0.93, Fig. 2). In contrast, titers of IgG-antibodies reached their maximum later, namely 31-60 days after onset of the disease (Table 1), and the correlation to the agglutinin-titers (r = +0.33, Fig. 3) was much lower. In sera of patients with typhoid fever reciprocal titers of IgM against the homogeneous group antigen surmounted those of IgG at the average by about 5 log2-step (mean g: 1404 and 79 respectively) between the 11th and 30th day of disease. At this stage of the disease also sera from patients with gastroenteritis due to both salmonella D or B demonstrated clearly an IgM-dominated ratio. After a period of more than 2 month this ratio was about 1:1 in sera of patients with typhoid fever or with salmonella group D-gastroenteritis, but was clearly IgG-dominated in sera obtained from patients with group B-gastroenteritis. This might be due to the fact that most of the sera classified as "obtained greater than 2 months after onset" stemmed from excreters of salmonella B species.(ABSTRACT TRUNCATED AT 400 WORDS)

Fluorescent bacterial rosetting of lymphocyte subpopulations. I. Methodology.

Fluorochrome-labelled bacteria were tested for their rosette-forming properties with human lymphocytes in suspension. Acridine orange stained human buffy coat cells or isolated mononuclear cells are rosetted with tetramethyl-rhodamine-isothiocyanate (TRITC)-labelled bacterial strains alone (mono-bacterial rosetting test) or simultaneously with a TRITC-labelled strain and a mutant or taxonomically different strain, labelled with fluorescein-isothiocyanate (double bacterial rosetting test [D-BRT]). Suspensions are centrifuged, washed, finally counterstained with ethidium bromide and examined by fluorescence microscopy. The bacterial binding properties of B cells may be studied by using anti-Ig pretreated mononuclear cells and TRITC bacteria (anti-Ig/BRT). In this study the methodology for bacterial staining, mono-, double- and anti-Ig/BRT is given. Estimation of rosette-forming cells is very accurate, easy and quick due to the bright fluorescence of the bacterial 'beads'. Furthermore, broad applicability of the bacterial rosetting phenomenon to study lymphocyte heterogeneity is gained with the fluorescent assay system.

Fluorescent bacterial rosetting of lymphocyte subpopulations. II. Identification of human lymphocyte subpopulations.

In a previous study, fluorochrome-labelled bacteria were found to be a very objective tool to investigate human lymphocyte heterogeneity with regard to bacterial rosette formation. The application of these assay systems (mono-, double- and anti-Ig/bacterial rosetting test) to identify lymphocyte subpopulations is given.

Species specificity in the binding of IgG to macrophages.

The binding of human IgG1 and IgG3 and rabbit IgG to guinea-pig peritoneal macrophages was examined, and differences between the species, in terms of their binding mechanisms, were characterized. Rabbit IgG bound with high affinity (Kass = 3.11 +/- 0.45 x 10(6) M-1) to a finite number of receptor sites per cell (1.26 +/- 0.29 x 10(6)) and competitively inhibited the binding of guinea-pig IgG2. Heterogeneity in binding, with distinct high and low affinity components, was observed when human IgG3 was reacted with guinea-pig macrophages, while human IgG1 exhibited only low affinity binding. Neither human IgG subclass competed effectively with guinea-pig IgG2 for its cell receptor. Thus, rabbit IgG appeared to cross-react with a macrophage receptor for guinea-pig immunoglobulin, whereas the human IgG subclasses bound to macrophage membrane components that remained undefined.