Testing of the World Health Organization-recommended formulations for surgical hand preparation and proposals for increased efficacy

The 2009 World Health Organization (WHO) Guidelines on hand hygiene in health care recommend alcohol-based hand rubs for both hygienic and pre-surgical hand treatment. Two formulations based on ethanol 80% v/v and 2-propanol 75% v/v are proposed for local preparation in healthcare settings where commercial products are not available or too expensive. Both formulations and our suggested modifications (using mass rather than volume percent concentrations) were evaluated for their conformity with the efficacy requirements of the forthcoming amendment of the European Norm (EN) 12791, i.e. non-inferiority of a product when compared with a reference procedure (1-propanol 60% v/v for 3 min) immediately and 3 h after antisepsis. In this study, the WHO-recommended formulations were tested for 3 min and 5 min. Neither formulation met the efficacy requirements of EN 12791 with 3 min application. Increasing the respective concentrations to 80 w/w (85% v/v) and 75 w/w (80% v/v), together with a prolonged application of 5 min, rendered the immediate effect of both formulations non-inferior to the reference antisepsis procedure. This was not the case with the 3h effect, which remained significantly inferior to the reference. Although the original formulations do not meet the efficacy requirements of EN 12791, the clinical significance of this finding deserves further clinical trials. To comply with the requirement of EN 12791, an amendment to the formulations is possible by increasing the alcohol concentrations through changing volume into mass percent and prolonging the duration of application from 3 min to 5 min.

In vitro activity of fosfomycin alone and in combination with amoxicillin, clarithromycin and metronidazole against Helicobacter pylori compared with combined clarithromycin and metronidazole

In order to evaluate the suitability of fosfomycin in combination with other agents for the treatment of Helicobacter pylori infections, the susceptibility profiles of 65 H. pylori strains were determined against multiple antimicrobial agents and combinations thereof using the agar dilution method. For fosfomycin alone, the range of minimum inhibitory concentration (MIC) results and the MICs at which 50% and 90% of strains were inhibited were 0.5-32 microg/ml and 2 and 4 microg/ml, respectively. For the combination of fosfomycin with amoxicillin, clarithromycin or metronidazole, the means calculated for the minimum and maximum fractional inhibitory concentration index were 0.70-1.17 and 1.15-2.03, respectively, suggesting partial synergy or indifference in the majority of strains. The combination of clarithromycin and metronidazole showed synergistic activity against 14 of 28 H. pylori strains tested. The in vitro activity results suggest the combination of fosfomycin with either amoxicillin or clarithromycin may be a promising alternative for the treatment of H. pylori infection. However, the clinical efficacy of these regimens remains to be investigated.

European norms in hand hygiene

In the area of hand hygiene, European Norms exist, or are under development, with regard to protective gloves and for assessing the antimicrobial efficacy of hand disinfectants. Important norms for gloves are EN 420 (General requirements), EN 374 (Protective gloves against chemicals and microorganisms) and EN 455 (Medical gloves for single use). A suspension test for the demonstration of bactericidal activity (prEN 12054) is obligatory for hand disinfectants in all fields of application; a test to prove activity against yeasts applies only to hygienic hand rub. (Optional) Claims for virucidal activities can be substantiated by prEN 1476 and, in future, for mycobactericidal capacity by a test which is still under development. In vivo tests exist for post-contamination treatments, hygienic hand wash and hygienic hand rub (EN 1499 and EN 1500 respectively), and for the preoperative surgical hand rub/wash (prEN 12791). The two former tests employ artificially contaminated hands, the latter test is done with clean hands. All in vivo tests use reference hand treatments (with unmedicated soap or 2-propanol 60% (vol.) or 1-propanol 60% (vol.), respectively) against the results of which are compared with those achieved with the product under test and with the same volunteers. An antiseptic soap needs to be significantly more efficacious than unmedicated soap, a product for hygienic hand rub must not be inferior to the reference treatment with 2-propanol, and a surgical hand disinfectant must not cause a smaller bacterial reduction than the reference preparation with 1-propanol, immediately, and after 3 h. An (optional) claim for sustained activity of a surgical disinfectant needs to be demonstrated by achieving a significantly stronger bacterial reduction after 3 h than the reference preparation.

Risk factors for nasal carriage of Staphylococcus aureus in infectious disease patients, including patients infected with HIV, and molecular typing of colonizing strains

Nasal carriage is an important risk factor for Staphylococcus aureus infection, particularly in HIV-infected individuals. In this analytical cross-sectional study, a variety of probable risk factors associated with nasal carriage of Staphylococcus aureus were investigated. HIV-infected patients were examined within a larger cohort of infectious diseases patients. Staphylococcus aureus strains from HIV-infected and non-HIV-infected carriers were identified by molecular biological analysis. One hundred seventy infectious disease patients, 47 of them infected with HIV, were included. All patients were admitted to the University Hospital of Vienna, Austria, between January and July 1999. Independent significant effects on Staphylococcus aureus nasal carriage were found to be HIV status (OR 2.5, 95% CI 1.1-5.6; P=0.0303), history of operation or severe wound within 3 months prior to admission (OR 4.0, 95% CI 1.3-13.0; P=0.0208), presence of an intravenous device within 2 weeks prior to admission (OR 10.8, 95% CI 2.0-59.4; P=0.0065), and intake of antibiotics within 2 weeks prior to hospitalisation (OR 0.2, 95% CI 0.09-0.6; P=0.0016). Molecular analysis of the Staphylococcus aureus strains revealed that the strains in both groups resembled those of healthy nonhospitalized carriers in the community.

Urease prevents adherence of Helicobacter pylori to Kato III gastric epithelial cells

The role of urease in Helicobacter pylori adherence to and internalization by Kato III cells was investigated. Kato III cells were incubated with wild-type strains (N6 or P1), with isogenic mutants lacking urease (N6ureB::TnKm or P1ureA::TnMax5) or producing the inactive apoprotein (N6ureG::TnKm), and with urease-positive clones recovered after complementation of N6ureB::TnKm with ureAB. Bacteria were stained with the green fluorescent dye PKH2, and the bacteria load of cells was analyzed by flow cytometry. With mutants lacking urease, the bacteria load was considerably increased, in comparison with the corresponding parental strains (P<.001). With clone K2(3), producing larger amounts of urease than N6, a significant reduction of bacteria load was observed, in comparison with the wild type (P<.001). N6ureG::TnKm showed adherence characteristics similar to those of N6. The role of urease in internalization was not clear. Thus, urease significantly inhibits H. pylori adherence to Kato III cells by a mechanism largely independent of enzymatic activity.

Application of blood-based polymerase chain reaction for detection of Chlamydia pneumoniae in acute respiratory tract infections

The aim of this study was to investigate whether blood-based polymerase chain reaction could serve as a diagnostic tool to identify individuals with acute respiratory Chlamydia pneumoniae infection. Respiratory specimens and peripheral blood mononuclear cells of 58 patients were analyzed using nested polymerase chain reaction and cell culture. Fifteen patients were polymerase chain reaction-positive for Chlamydia pneumoniae. Nine patients were positive in only the respiratory specimen; two in both the respiratory and blood sample (time intervals between onset of symptoms and sample collection, 3-10 days and 3-4 weeks, respectively); and four in only the blood sample. Detection of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells does not seem to be a suitable marker for acute respiratory Chlamydia pneumoniae infection.

Arguments for alcoholic hand disinfection

The non-aqueous use of ethanol or propanols offers various advantages over washing hands with either unmedicated or medicated soap in both hygienic and surgical hand disinfection. Alcohols exert the strongest and fastest activity against a wide spectrum of bacteria and fungi (but not bacterial spores) as well as enveloped (but less so against non-enveloped) viruses, being little influenced by interfering substances. They are of low toxicity and offer acceptable skin tolerability when made up with suitable emollients. The mode of their application is simple and three to four times more economical of time than wash procedures, features which help to increase the compliance with the rules of hand hygiene.

Multicenter comparison trial of DNA extraction methods and PCR assays for detection of Chlamydia pneumoniae in endarterectomy specimens

The reported rate of detection of Chlamydia pneumoniae DNA within atherosclerotic lesions by PCR varies between 0 and 100%. In this study, identical sets of coded experimental atheroma samples (n = 15) and spiked controls (n = 5) were analyzed by 16 test methods in nine centers by means of PCR. The positive controls were correctly identified to levels of 1, 0.1, and 0.01 inclusion bodies of C. pneumoniae/ml of tissue homogenate by 16 (100%), 11 (69%), and 3 (19%) of the test methods, respectively. Three out of 16 negative controls (19%) were rated positive. Positivity rates for atheroma samples varied between 0 and 60% for the different test methods, with the maximum concordant result for positivity being only 25% for one carotid artery sample. There was no consistent pattern of positive results among the various laboratories, and there was no correlation between the detection rates and the sensitivity of the assay used.

Two enzyme immunoassays and PCR for detection of Helicobacter pylori in stool specimens from pediatric patients before and after eradication therapy

This study of pediatric patients was intended to determine the suitability of stool PCR and two antigen enzyme immunoassays (EIAs; Premier Platinum HpSA and the novel FemtoLab H. pylori), which detect Helicobacter pylori antigens in feces, as pretreatment diagnostic tools and especially as posttreatment control. Forty-nine H. pylori-infected children with dyspepsia received eradication therapy. Successful treatment was determined by a negative [(13)C]urea breath test 4 and 12 weeks after discontinuation of therapy. Fecal specimens were collected prior to eradication therapy as well as 4 weeks after the end of treatment. Successfully treated children delivered stool samples at 6, 8, and 12 weeks posttreatment also. Specimens were examined by seminested PCR and Premier Platinum HpSA and were reexamined by both EIAs as soon as FemtoLab H. pylori was available. In the first test series, the overall sensitivities of PCR and Premier Platinum HpSA were 93.0 and 91.1%, respectively. With specimens collected at 4 weeks after treatment, the respective specificities were 68.8 and 79.3%. After longer follow-up periods, however, they gradually increased to 100 and 96.9%, respectively. In the new test series, Premier Platinum HpSA delivered a considerably lower number of false-positive results (4 versus 18), indicating intertest variations. The overall test sensitivity was 94.6%, and the overall specificity was 97.5%. FemtoLab H. pylori showed an excellent performance with an overall sensitivity and specificity of 98.2 and 98.1%, respectively. Thus, in contrast to PCR, both EIAs were shown to be suitable for early posttreatment control.

In vitro activities of linezolid alone and in combination with amoxicillin, clarithromycin, and metronidazole against Helicobacter pylori

Linezolid was tested against 70 strains of Helicobacter pylori by the agar dilution method. The MIC range and MICs at which 50 and 90% of strains were inhibited were 8 to 64, 16, and 32 microgram/ml, respectively. With minimum and maximum fractional inhibitory concentration summation values of 0.31 and 2.50, respectively, the combination of linezolid with amoxicillin, clarithromycin, or metronidazole showed either partial synergy or indifference for the majority of strains.

Purification of surface-associated urease from Helicobacter pylori

Helicobacter pylori colonizes the human gastric mucosa and produces large amounts of urease. The enzyme was extracted from the bacteria by distilled water and purified by gel-permeation (Sephacryl S-300), anion-exchange chromatography (Mono Q) and a second gel-permeation (Superdex 200). Urease enzyme activity was detected with a spectrophotometic assay based on phenol red. The optimal pH for anion-exchange was 6.9. The recovery of urease was 55-75%, purity 93-98% and the overall protein recovery 0.8-1.4%. The urease in the final extract still had enzymatic activity and showed the typical subunits of Mr 66000 and Mr 30000 when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Helicobacter pylori urease significantly reduces opsonization by human complement

The role of Helicobacter pylori urease in opsonization by human complement was investigated. H. pylori wild type strain N6 and isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) were incubated with different sera. C3b bound to the bacteria was measured by specific staining and flow cytometry. As compared with opsonization of N6 and the UreG-lacking mutant, opsonization of the UreB-lacking mutant was significantly increased after incubation with sera from both H. pylori uninfected (P<.001) or infected (P<.05) persons. However, when sera from uninfected persons were used, effective opsonization of this mutant proved to be dependent mainly on the classical pathway of complement activation. Irrespective of the serum used, opsonization values were very low after selective inactivation of the classical or the alternative pathway. Reduced opsonization of the urease-expressing strains could, to some extent, result from degradation of bound C3b.

Surgical hand disinfection with alcohols at various concentrations: parallel experiments using the new proposed European standards method

OBJECTIVES

To establish the concentration of isopropanol that exerts the same immediate and sustained effects as n-propanol 60% v/v in surgical scrubbing, and to assess the performance of the test method proposed as the European standard in parallel experiments.

DESIGN

Isopropanol at concentrations of 70%, 80%, and 90% v/v was tested in comparison with n-propanol 60%, the proposed reference preparation, in the draft method proposed by the European standard. A Latin square design was used with four balanced blocks of five volunteers each in four experimental runs that were spaced by intervals of 1 week each. Volunteers were allotted randomly to one of the four blocks. Independently, the volunteers' right and left hands also were randomized into two groups for the assessment of either immediate or sustained effects.

SETTING

Two laboratories supervised by two investigators, one from Vienna, Austria, and one from London, The United Kingdom.

METHOD

The release of skin flora from the fingertips of clean hands was assessed before and after treatment by immediate sampling from one hand and by sampling of the other, gloved hand after 3 hours. The mean log10 reductions (RF) of bacterial release achieved by rubbing the alcoholic preparations for 3 minutes onto the hands were established.

RESULTS

For both experiments, the immediate effects of isopropanol 70% (RF, 2.0 and 2.1, respectively) were significantly smaller than those of the reference n-propanol 60% (RF, 2.4 and 2.6, respectively). This also was found with the sustained effects (RF, 0.7 and 1.1 vs 1.0 and 1.6, respectively). At 90%, isopropanol equalled the immediate effect of n-propanol 60%, whereas at 80% it proved slightly (although not significantly) less active. There were no significant differences in the results of both investigators. The sustained effects of isopropanol 80% and 90% were both larger than the reference in Vienna but were found smaller by the London investigator; none of the differences were significant. Mean RFs were significantly different between Vienna and London with n-propanol 60% and isopropanol 70%, but not with isopropanol at 80% or 90%.

CONCLUSIONS

At 90%, isopropanol is as effective as n-propanol 60%, which was proposed by the European Committee for Standardization as a reference in testing products for surgical hand disinfection. It could, therefore, serve as an alternative if the proposed agent is undesirable for any reason. In parallel experiments by two investigators, the proposed test method proved well workable; the results were very similar and the conclusions identical.

Detection of Helicobacter pylori in stool specimens by PCR and antigen enzyme immunoassay

A highly sensitive seminested PCR assay to detect Helicobacter pylori DNA in feces was developed. PCR with stool specimens and a novel antigen enzyme immunoassay (EIA) for H. pylori detection in feces were evaluated as diagnostic tools and in follow-up with samples from 63 infected and 37 noninfected persons. Infected individuals received eradication therapy followed by endoscopic follow-up 35 days after the start of treatment. At that time, a second stool specimen was obtained from 55 of these patients. Before eradication, the sensitivity of PCR was 93.7% and that of EIA 88.9%. Specificities were 100 and 94.6%, respectively. Of the 55 follow-up specimens, 41 originated from patients from whom H. pylori had been eradicated. Of these, 21 were still positive by PCR and 13 were positive by EIA, indicating that 1 month may be too short a period for follow-up evaluation of stool specimens by these tests.

Semmelweis' sesquicentennial: a little-noted anniversary of handwashing

This review describes Semmelweis' achievement 150 years ago. User acceptability of hand disinfectants has been improved, but Semmelweis' observation that handwashing, in contrast to hygienic hand disinfection, is not always sufficiently effective, is not yet generally acknowledged, and the compliance of medical personnel to the rules of hand hygiene still remains an educational problem to be solved.

Highly significant role of Helicobacter pylori urease in phagocytosis and production of oxygen metabolites by human granulocytes

The contribution of Helicobacter pylori urease, the vacuolating cytotoxin VacA, and the 128-kDa protein CagA to the stimulation of human granulocytes in terms of phagocytosis and oxidative burst was evaluated. Blood was incubated with H. pylori strains and corresponding isogenic mutants lacking either the large urease subunit (UreB) or an accessory urease protein (UreG) or VacA or CagA. Phagocytosis and oxidative burst were monitored by flow cytometry. The UreB-lacking mutant was phagocytosed more efficiently (P < .001) and induced significantly less oxidative burst (P < .001) than its parental strain or the UreG-lacking mutant, which produces an enzymatically inactive urease. Values of the other mutants did not differ greatly from those of their parental strain. These data indicate inflammatory effects of H. pylori urease causing inhibition of phagocytosis and stimulation of oxidative burst by a pathway being largely independent of ammonia production.

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.

Molecular typing of Acinetobacter baumannii from ten different intensive care units of a university hospital

Thirty-one isolates of Acinetobacter baumannii were collected from ten intensive care units of an Austrian university hospital. All isolates were typed by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Two strains colonizing 13 infants in the neonatal intensive care unit were identified by ERIC-PCR. All other Acinetobacter baumannii isolates had highly divergent ERIC-PCR patterns, despite having the same antibiogram. Thus, a hospital-wide clonal distribution, as suggested by identical antibiogram patterns, was excluded by ERIC-PCR.

Amoxicillin for the treatment of Helicobacter pylori infection

Amoxicillin is one of the most active antimicrobials against Helicobacter pylori in vitro, with a minimum inhibitory concentration (MIC) of < or = 0.01-0.1 mg/l. Thus far, neither primary nor secondary resistant strains have been found. Amoxicillin, which has a bactericidal effect on H. pylori, but is less inhibitory in the stationary growth phase and against cell-adherent or slowly growing H. pylori, probably has both topical and systemic activity. It is fairly acid stable and is less affected by gastric acidity than macrolides. Nevertheless, its activity in vivo is considerably enhanced when it is given concomitantly with proton pump inhibitors. Several amoxicillin-containing treatment regimes have yielded H. pylori eradication rates of > or = 90%. Of particular interest are 1-week treatment regimens containing amoxicillin + clarithromycin + omeprazole, or amoxicillin + metronidazole + omeprazole, as well as a 1-h topical therapy developed in Japan.

Serological tests for monitoring Helicobacter pylori eradication treatment

Serological tests for the detection of Helicobacter pylori-specific antibodies are useful in epidemiological studies, as a pre-endoscopic screening procedure, and as therapeutic follow-up. For the latter application, they represent an alternative to invasive and expensive diagnostic methods such as endoscopy and breath test, respectively. However, serological tests are suitable only for long-term treatment monitoring in adults. As the significant reduction of specific antibodies, and not seronegativity by itself, is regarded as a criterion of therapeutic success, it is always necessary to establish the antibody kinetics. Enzyme-linked immunosorbent assay (ELISA) based tests are best suited for this. The most relevant antibody class to be detected is H. pylori-specific IgG. The main indication for employing serology is the therapeutic follow-up of patients who, on the whole, are free of complaints.

Influence of zinc oxide on Aspergillus species: a possible cause of local, non-invasive aspergillosis of the maxillary sinus

Recently the appearance of radiopaque 'concrements' in the maxillary sinus was reported. These radiodense objects could be identified as root-filling material for teeth of the upper jaw containing zinc oxide. This suggested that excess root-filling material containing zinc oxide in the maxillary sinus could favour the formation of a local, non-invasive aspergillosis. To verify this hypothesis in vitro, we tested the influence of zinc oxide on Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, A. niger and A. niveus. A geometric series of zinc oxide diluted in 0.1 N H2SO4 was used. Czapek-Dox agar was inoculated with the six Aspergillus species. Circular cavities stamped into the centre of each agar plate were filled with an equal amount of the dilutions and all plates were then incubated for 7 days at 37 degrees C. Readings were taken on days 3, 5 and 7. Soluble zinc oxide promoted the growth of all the tested Aspergillus species, the effect diminishing with decreasing concentration. This effect could be observed on all days of measurement. Only with A. niger was stimulation of growth minimal, probably because this species already exhibits a high growth rate on Czapek-Dox agar. Therefore, overfilling of maxillary teeth with a zinc oxide-containing root-filling material may favour the formation of local aspergillosis.

[Effect of zinc oxide on Aspergillus species: a possible cause of local noninvasive aspergillosis of the maxillary sinus]

During the last years the appearance of radiopaque concrements in the maxillary sinus was reported. These could be identified as root-filling material for teeth of the upper jaw containing zinc oxide. This suggested that excess root-filling material containing zinc oxide in the maxillary sinus could favour the development of a local, non-invasive aspergillosis. Therefore, we tested Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans and A. niveus for the influence of zinc oxide. Cza-pek-Dox agar was inoculated with the six different Aspergillus strains. Circular cavities stamped into the agar's center of each plate were filled with aliquots of the dilutions of a geometric series of zinc oxide dissolved in 0,1n H2SO4. All plates were then incubated for seven days at 37 degrees C. Readings were taken on the 3rd, the 5th and the 7th day. It became obvious that solved zinc oxide promotes the growth of all the tested Aspergillus species. This influence diminished with decreasing concentration. This effect could be observed on all days of measurement. Only A. niger showed an attenuated dependence, probably due to the a priori high growth rate of this species on Czapek-Dox agar. It is concluded that overfilling of maxillary teeth with a zinc oxide containing root filling material favours the development of local aspergillosis.

Do 'chlorine covers' exert a sustained bactericidal effect on the bacterial hand flora?

Treatment of skin with chlorine generates 'chlorine covers' which, in a previous study, exerted significant sustained bactericidal effects against transient skin flora on the upper arm and forearm. In this investigation, this effect was studied on both the transient and resident flora of the hands using test models for the evaluation of hand disinfectants as agreed upon in Austria and Germany. Chlorine covers were generated by bathing hands in a solution of 2% sodium tosylchloramide for 1 min. Subsequently, this cover was destroyed on one, randomly selected, hand by bathing it in a solution of 0.5% sodium thiosulphate for 15 s. The amount of chlorine on the fingertips of chlorinated hands was 2.2 +/- 0.4 micrograms/cm2; that on subsequently dechlorinated hands was 0.2 +/- 0.1 microgram/cm2. In experiments with artificially contaminated hands (Escherichia coli), the kinetics of bacterial die-off were the same on both hands. Also, in experiments with resident flora, the kinetics of bacterial die-off did not suggest bacterial reductions that increase with the duration of contact with the chlorine cover. It was concluded that with the test models used, a significant sustained antimicrobial effect of the chlorine cover could not be demonstrated on hands.

Polymerase chain reaction for detection of Chlamydia pneumoniae in gargled-water specimens of children

The objective of the present study was to establish the occurrence of Chlamydia pneumoniae by direct detection in gargled-water specimens obtained from 193 children suffering from acute or chronic respiratory infections. Specimens were analyzed by an indirect immunofluorescence test (IIF), a genus-specific antigen enzyme immunosorbent assay (EIA) and the polymerase chain reaction (PCR). The pathogen was detected in three children by PCR only. As underlying disease, chronic obstructive bronchitis resistant to therapy was reported. In two of the children, the presence of pneumonia could be verified by X-ray. With a detection threshold of target DNA obtained from two inclusion forming units (IFU), the PCR proved clearly more sensitive than EIA becoming positive at levels of 100 IFU and above. No interpretable results could be obtained for the IIF.

Epidemiological analysis of Candida yeasts by pulsed-field gel electrophoresis

The purpose of this study was to determine whether yeast isolates from mothers and their new-borns are of the same genotype. In this investigation, 103 parturient mothers and their children were examined for colonization by yeasts by sampling the vaginal secretions at delivery and by taking swabs from the oral mucosa and the anus of the children on the third day after parturition. The samples were cultured on Sabouraud glucoseagar and incubated for 48 h at 37 degrees C. Differentiation of the isolates was achieved biochemically by means of the Vitek AMS system and morphologically on rice extract agar. Subsequently DNA fingerprinting analysis was carried out by means of pulsed-field gel electrophoresis (PFGE). In six cases we could prove the presence of Candida spp. in the mothers as well as in their children. In all cases the strains isolated from mother and child showed the same banding pattern. Likewise, the strains isolated from the vaginal secretion and the vaginal epithelium of individual women were identical. The differences observed between strains isolated from different women were small to middling. This shows PFGE to be an efficient procedure to demonstrate the relation between strains derived from mothers and their newborns.

Single and multiple strain colonization in patients with Helicobacter pylori-associated gastritis: detection by macrorestriction DNA analysis

Helicobacter pylori isolates from 18 patients were examined by macrorestriction DNA analysis to determine whether > or = 2 strains can coexist in the human stomach. Four biopsy samples from different sites in each patient's stomach were cultured, and 12-14 clones of H. pylori per patient were analyzed. DNA of 15 of the 18 isolates was digestible: 12 by NotI and 3 by NruI. Within 14 of these digestible isolates, the patterns of all clones were identical. The isolate of 1 patient showed two digestion patterns, a finding that was confirmed by arbitrary primer polymerase chain reaction. The typeable isolates of all patients, except 2 who underwent gastroscopy on the same day, differed markedly from each other. These results indicate a noticeable discrepancy between the pronounced interpatient heterogeneity and the rare intrapatient variation of H. pylori.

Kinetics of specific IgG antibodies for monitoring the effect of anti-Helicobacter pylori chemotherapy

A total of 104 patients with recurrent duodenal ulcer were treated with either ranitidine plus amoxicillin plus metronidazole or ranitidine plus placebo. To study the effect of the eradication of Helicobacter pylori on the systemic immune response in an IgG ELISA, sera were drawn from all patients before the onset of therapy and at 6, 16 +/- 2, 32 +/- 2, and 60 +/- 2 weeks after therapy. In patients with eradication of the organism, a significant (P < .001) reduction of the specific IgG titer occurred. This was not observed in patients without bacterial eradication. If a titer reduction of > 50% was taken as an indicator for eradication of H. pylori, the sensitivity of the serologic test was 97.6%-99.7%. Its specificity increased with the interval to the onset of chemotherapy from 56.3% to 97.6%. Serologic tests are simple to perform and cause very little discomfort to the patient.

Comparison of three methods for the determination of the sensitivity of Helicobacter pylori to metronidazole

A comparison of various methods for the determination of the sensitivity of Helicobacter pylori to metronidazole was undertaken. The validity of the agar dilution, the disc diffusion and the Epsilometer (E) test was studied using a total of 86 strains, 16 of which were known to be resistant to metronidazole. All tests were carried out on Mueller-Hinton agar with 5% sheep blood. The results of the disc diffusion and the E-test were highly significantly (P < 0.001) associated with those of the agar dilution test, which was taken as a standard (r = -0.96 and r = 0.96, respectively). Investigation of the accuracy of the repetitive (n = 10) testing ten sensitive and one resistant strains, showed that the disc diffusion test led to a systematic and significant (2p < 0.001) underestimation of the MIC values calculated from the inhibition zone diameters via linear regression. In contrast, the results of the E-test did not differ significantly from those of the agar dilution test. The precision of the agar dilution test was significantly worse (2p < 0.005) than the E-test and the disc diffusion test. Because of its accuracy and significantly better precision, the E-test is recommended as the best and simplest method for routine antibiotic sensitivity testing of H. pylori.

Test models for hygienic handrub and hygienic handwash: the effects of two different contamination and sampling techniques

Two methods for artificial contamination of hands and two sampling techniques to recover the test organisms were compared for their effects on the results of two post-contamination hand treatments: a handrub with two portions of 3 ml of 2-propanol 60% v/v for 1 min, and a handwash with liquid soap 20% w/v for 1 min followed by a 15 s rinse. The two contamination methods involved a short immersion of the hands (up to the middle of the mid-hand) in a suspension of the test organism followed by either air-drying (3 min) or drying by rubbing the hands' vigorously against each other (3 min) in a standardized way. The two sampling techniques consisted of rubbing the fingertips in either 10 ml trypticase soy broth (TSB) against the bottom of a Petri dish; or 100 ml TSB against glass beads contained in a bowl. Sixteen volunteers were randomly allotted to four blocks of four. They carried out the four possible combinations of two treatments and two contamination methods in a series of four tests arranged in a Latin-square design. In addition, the two sampling techniques were compared with each other concurrently by sampling of the right and left hand each with a different one of the two techniques. The alcoholic handrub reduced the release of test organisms significantly (2P less than 0.005) more effectively, by 1.1-1.3 x log10, than did the handwash with liquid soap, regardless of the contamination or sampling method. Whereas the two recovery techniques yielded virtually identical results in corresponding situations, the method of artificial contamination affected the mean reduction factors, strongly.(ABSTRACT TRUNCATED AT 250 WORDS)

A new plate medium for rapid presumptive identification and differentiation of Enterobacteriaceae

A new selective differential agar medium for rapid presumptive identification of Enterobacteriaceae from water and food samples is described (EMX ID agar). By a combination of fluorogenic and chromogenic substrates, the medium detects the presence of beta-D-glucuronidase, beta-D-galactosidase, beta-D-xylosidase, tryptophane deaminase and H2S; additionally, cytochrome-oxidase and indole production can be demonstrated. This medium provides an inexpensive means for simple and rapid presumptive identification of E. coli and coliforms and for the differentiation within the Klebsiella-Enterobacter and the Proteus-Providencia-Morganella group. Furthermore, it allows to distinguish between the H2S-positive Enterobacteriaceae Citrobacter freundii, Salmonella spp., S. arizonae, Edwardsiella, Proteus mirabilis, P. vulgaris and some oxidase-positive bacteria.

Evaluation of a commercial latex test for serological diagnosis of Helicobacter pylori infection in treated and untreated patients

The value of a commercially available latex test (Pyloriset) for the diagnosis of Helicobacter pylori infection by demonstration of specific antibodies was compared with that of direct diagnostic methods such as culture, biopsy-urease test and microscopy of fuchsin-stained smears. The sera were from 136 patients who prior to this study either had or had not been treated for Helicobacter pylori-infection simultaneously with amoxicillin (3 x 750 mg/day) and metronidazole (3 x 500 mg/day) for 12 days. On average, the sensitivity of the test was 90%. The specificity with sera from untreated patients was 75.9%; with sera from treated patients specificity was 22.2%, 28% and 20% 1, 3 and 6 months respectively after start of treatment. Only as late as one year after the onset of chemotherapy did the specificity return to 67%. Because of its low specificity this test does not offer any advantage over other tests in the detection of Helicobacter pylori-infection or in monitoring the chemotherapeutic success.

The influence of cosmetic additives on the acceptability of alcohol-based hand disinfectants

A prospective, randomized double-blind study with intra-individual comparison of the results was undertaken with 20 volunteers to assess the influence of cosmetic additives on the acceptability of a mixture of n-propanol (50% v/v) and isopropanol (30% v/v) for hand disinfection. Three to 5 ml of antiseptic was rubbed into the hands until dry 15 times a day, 5 days a week and for 2 weeks per preparation. For self-assessment the parameters 'appearance', 'intactness', 'turgor' and 'sensation' were evaluated weekly by visual analogue; for assessment by a dermatologist the same parameters except 'sensation' were used. Each score was compared before and after treatment. The antimicrobial efficacy of the alcoholic mixture was equivalent to or better than the standard (isopropanol 60% v/v, 1 min). The frequent application of these antiseptic preparations caused a slight but significant deterioration of the skin condition as judged by both self-assessment and dermatologist; however, this was significantly less when the antiseptic contained cosmetic additives. It is concluded that the addition of suitable emollients can significantly increase the acceptability of alcoholic disinfectants.

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.

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.

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.

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).

A comparison of the effects of preoperative whole-body bathing with detergent alone and with detergent containing chlorhexidine gluconate on the frequency of wound infections after clean surgery. The European Working Party on Control of Hospital Infections

In a prospective, randomized, double-blind, placebo-controlled study involving 27 surgical units in six European countries, the effect of preoperative whole-body bathing on two occasions with a detergent containing chlorhexidine (CHX+) on the incidence of wound infection in elective, clean surgery was compared with two bathings with a detergent without chlorhexidine (CHX-). In the CHX+ group 2.62% of 1413 patients and in the CHX- group 2.36% of 1400 patients subsequently became infected. The infection rate in the CHX+ group was 1.11 times that in the CHX- group with 95% confidence limits ranging between 0.69 and 1.82. Consequently, bathing patients twice preoperatively with chlorhexidine-detergent did not reduce the incidence of infection of clean wounds.

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.

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.

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.

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.

Evaluation of procedures for hygienic hand-disinfection: controlled parallel experiments on the Vienna test model

Controlled parallel experiments were performed on the Vienna test model for the evaluation of procedures for hygienic hand-disinfection in three laboratories (Vienna, Mainz, Birmingham). The degerming activity of four procedures, each taking 1 min, was assessed repeatedly and compared with that of a standard disinfection procedure (ST) using isopropanol 60% (v/v). The mean log reductions (mean log RF) for each procedure were as follows: n-propanol 50% (v/v) 4.85 and 5.14 in Vienna (V) and Mainz (M) respectively, ethanol 70% (v/v) + chlorhexidine-gluconate 0.5% (w/v), 4.01 (V), 3.76 (M) and 4.00 in Birmingham (B). Washing procedures were less effective, mean log RF's of 3.19 (V), 3.49 (M) and 3.04 (B) were obtained with povidone-iodine soap, and 2.91 (V), 3.37 (M) and 3.27 (B) with a liquid phenolic soap. Analysis of variance on the data from Vienna and Mainz revealed significant differences of means not only between procedures ('preparations') but also on repeat testing. To compensate for the influence of variables such as test subjects, laboratory and day, the Vienna test model provides a method of standardization by testing a ST in parallel with the test procedure (P). Standardization of the results was obtained by pair-wise substraction, log RFPi-log RFSTi. Analysis of variance on the resulting values demonstrated that comparability of the results between laboratories and on repeat testing was achieved. The relative variation of the measurements within the laboratories ranged from 0.9 to 4.2%. As assessed by power-analysis, a disinfection procedure will be detected as significantly (P = 0.1) inferior to the standard processes in 95 of 100 experiments if it produces a mean log RF that is at least 0.55-0.65 log units smaller than that of the standard.