A new method for normalized interpretation of antimicrobial resistance from disk test results for comparative purposes.

Objective To evaluate a calibration method for disk diffusion antibiotic susceptibility tests, using zone diameter values generated in the individual laboratory as the internal calibrator for combinations of antibiotic and bacterial species. Methods The high-zone side of zone histogram distributions was first analyzed by moving averages to determine the peak position of the susceptible population. The accumulated percentages of isolates for the high zone diameter values were calculated and converted into probit values. The normal distribution of the ideal population of susceptible strains was then determined by using the least-squares method for probit values against zone diameters, and the ideal population was thereby defined, including mean and standard deviation. Zone diameter values were obtained from laboratories at the Karolinska Hospital (KS) and Växjö Hospital (VX), and from two laboratories (LabA, LabB) in Argentina. The method relies on well standardized disk tests, but is independent of differences in MIC limits and zone breakpoints, and does not require the use of reference strains. Resistance was tentatively set at below 3 SD from the calculated, ideal mean zone diameter of the susceptible population. Results The method, called normalized interpretation of antimicrobial resistance, was tested on results from the KS and VX clinical microbiology laboratories, using the disk diffusion method for antimicrobial susceptibility tests, and for two bacterial species, Staphylococcus aureus and Escherichia coli. In total, 114 217 test results were included for the clinical isolates, and 3582 test results for control strains. The methodology at KS and VX followed the standard of the Swedish Reference Group for Antibiotics (SRGA). Zone diameter histograms for control strains were first analyzed to validate the procedure, and a comparison of actual means with the calculated means showed a correlation coefficient of r = 0.998. Results for clinical isolates at the two laboratories showed an excellent agreement for 54 of 57 combinations of antibiotic and bacterial species between normalized interpretations and the interpretations given by the laboratories. There were difficulties with E. coli and mecillinam, and S. aureus and tetracycline and rifampicin. The method was also tested on results from two laboratories using the NCCLS standard, and preliminary results showed very good agreement with quality-controlled laboratory interpretations. Conclusions The normalized resistance interpretation offers a new approach to comparative surveillance studies whereby the inhibition zone diameter results from disk tests in clinical laboratories can be used for calibration of the test

Droner som FKT - bruk av droner som forebyggende tiltak i beitenæringen

Utmarksbeitende dyr er utsatt for angrep fra fredet rovvilt. I oppdrag fra rovviltnemnda i region 6 Midt-Norge undersøker vi den mulige nytteverdien av droner i åpen kategori som forebyggende- og konfliktdempende tiltak (FKT). Utredningen er basert på informasjon fra intervjuer, faglitteratur og dronetestflygninger.Droner som FKT kan brukes under (1) tilsyn, (2) flytting av dyr fra rovdyrutsatte områder, (3) automatisk gjenkjenning og telling av dyr, (4) overvåkning av rovdyrutsatte områder, (5) kadaversøk, (6) søk av skadete eller skremte beitedyr og (7) sporing av rovdyr. Dronebruk i åpen kategori er delvis mulig for (1) – (3) så lenge dronen er innen synsrekkevidden. Slike operasjoner kan ikke skilles fra vanlig drift. Operasjoner under (4) – (7) må dekke større områder og må utføres i spesifikk kategori. Effektiviteten av slike droneoperasjoner er ukjent. Droner kan brukes i alle typer habitat ved å tilpasse sensorene for fjernmåling. Regelverket, signaldekning, vær- og lysforhold setter begrensninger. Dronesystemer i åpen kategori er lett, enkle å bruke, transportere og lade. Mer avanserte droner (<25 kg) er dyre og vanskelig å transportere og lade og brukes best i spesifikk kategori for mer varierte FKT-formål. I nær framtid kan droner f.eks. brukes til sporing av beite- og rovdyr, kadaversøk og skremming, samt innhenting av data fra elektroniske sporingsenheter på dyr. Til og med selvgående droner som rykker ut når en nødsituasjon oppstår er mulig. Effektiviteten bør testes under norske lys- og værforhold. I samsvar med en rask teknologiutvikling krever økt dronebruk i utmark økt oppmerksomhet omkring konsekvensene med hensyn til offentlig sikkerhet, personvern og ikke minst dyreliv.Droner som FKT - bruk av droner som forebyggende tiltak i beitenæringenpublishedVersio

Biological weapons inspections - The Iraq experience

Prior to the 1990 Iraq-Kuwait conflict it was well known that Iraq had developed weapons of mass destruction but the extent of its programs were unclear. After the Iraqi defeat in the ensuing Gulf war 1991 the UN Security Council authorized the creation of UN Special Commission for Iraq (UNSCOM) with the purpose of ridding Iraq permanently of weapons of mass destruction. Several conclusions can be drawn from more than ten years of biological weapons inspections in Iraq. Firstly, UNSCOM managed to get a rather clear picture of the past weapons programs. Secondly, it was not possible for Iraq to restart a substantial program with UNSCOM being present in the country. Thirdly, a full and final and complete account of the weapons program could not be established despite the use of the best intellectual and technical capabilities available at the time

Specificity of Fc receptors induced by herpes simplex virus type 1: comparison of immunoglobulin G from different animal species

Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind the Fc portion of immunoglobulin G (IgG). Of the four human IgG subclasses, the HSV-1 Fc receptor, like staphylococcal protein A, binds to all except IgG3. In this paper, we describe the binding of a number of animal IgG and IgG subclass molecules to HSV-1-infected cells and compare this binding to that of protein A. Although only few representatives from each animal order were tested, we found that IgG from Carnivora and Rodentia did not bind or bound only slightly to the HSV-1 receptor, whereas IgG from Primates, Lagomorpha, and Artiodactyla bound well. This pattern was clearly different from the species spectrum of IgG binding of protein A. Differences between the two receptors were also found when animal IgG subclasses were tested. The pronounced differences in affinity for the HSV-1 Fc receptor between immunoglobulins from, for example, mouse and rabbit may influence the interpretation of animal studies with this virus

Clinical and Serological Variation between Patients Infected with Different Hepatitis B Virus Genotypes

Hepatitis B virus (HBV) has eight genotypes which have distinct geographical distributions. Studies comparing differences in the clinical outcomes of infections caused by strains with genotype-related variations in the HBV genome have largely compared genotypes B and C and genotypes A and D but not all four genotypes. The present study included 196 HBV-infected patients attending an infectious diseases outpatient clinic in Sweden. The age and geographic origin, liver function, HBeAg and anti-HBe status, and the presence or absence of HBV DNA were analyzed for each patient. HBV DNA was detected in 144 patients, and the HBV genotype and the core promoter and precore sequences were determined for the isolates from 101 of these patients. Among the patients who might be considered most likely to be nonviremic, namely, anti-HBe-positive HBV carriers with normal alanine aminotransferase (ALT) levels, 65% had detectable HBV DNA and were thus viremic. Among the viremic patients, HBeAg-positive patients were more likely to have elevated ALT levels than anti-HBe-positive patients. HBV genotypes A to F were represented in the study, and their distributions coincided accurately with the origin of the patient. A significantly higher number of genotype D-infected patients were anti-HBe positive and had elevated ALT levels (42% of genotype D-infected patients but 0% of patients infected with genotypes B and C). Genotype D strains with mutations in the core promoter and precore regions were significantly correlated with elevated ALT levels in the patients. The differences were not age related. Therefore, in this large-scale cross-sectional study, genotype D appears to be associated with more active disease

Fractionation of rat IgG subclasses and screening for IgG Fc-binding to bacteria

The four IgG subclasses of the rat, IgGl, IgG2a, IgG2b and IgG2c, were purified from normal serum by a combination of protein A-affinity chromatography and DEAE-cellulose chromatography. Purified, radiolabelled preparations of IgG were tested for binding to Gram-positive bacteria representing five different Fc-receptor (FcR) types. Distinct rat subclass-specific Fc-binding was noted to bacterial species belonging to different Fc-receptor types. Staphylococcus aureus (FcR I) strains bind IgGl and IgG2c as shown by others. Group C and G Streptococci (FcR III) bind all four subclasses of rat IgG. Streptococcus zooepidemicus strains (FcR V) also bind all four subclases but only to a lower degree. Human group A Streptococci (FcR II) and bovine group G Streptococci (FcR IV) do not bind any of the rat IgG subclasses. Elution studies on two strains. Staphylococcus aureus, Cowan I, and human group G Streptococcus, G 148, showed that both thiocyanate and pH-elution might be useful for the fractionation of IgG subclasses bound to bacterial cells. The present work indicates the possible use of bacterial cells as solid-phase absorbents in immunological studies of rat IgG