Determination of the intramammary dose of benzylpenicillin required to maintain an adequate concentration in the milk to inhibit Gram-positive bacteria in the clinically normal udder for 24 hr

The aim of this study was to determine the intramammary dose of benzylpenicillin required to maintain a concentration in the milk above the MIC for the Gram-positive bacteria that cause mastitis. The product used in this study was a commercially available procaine benzylpenicillin in an oily suspension with micronized particles. Three dose levels were used: 200,000, 300,000, and 600,000IU. Concentrations of benzylpenicillin in cow milk and plasma were determined after a single intramammary dose was administered into one quarter of each of the five cows in each treatment group. Samples were analyzed using an HPLC-MS/MS method, which was validated during the study. Concentrations in the milk were well above the MIC for the target pathogens for all doses tested. There was a linear dose-dependent increase in the mean AUCs of benzylpenicillin concentrations in plasma and milk. At the first milking, 12hr after dosing, there was a significant difference between the mean milk benzylpenicillin concentrations in cows treated with a dose of 600,000IU, and those treated with 200,000 or 300,000IU. Although this study shows a linear relationship between the dose of procaine benzylpenicillin administered and the concentration in the milk in the healthy udder, it would be useful to conduct studies on cows with mastitis to define the optimum dose and duration of intramammary treatment with benzylpenicillin.Peer reviewe

Prevention of urinary tract infections in nursing homes: lack of evidence-based prescription?

<p>Abstract</p> <p>Background</p> <p>Urinary tract infections (UTIs, including upper and lower symptomatic) are the most common infections in nursing homes and prevention may reduce patient suffering, antibiotic use and resistance. The spectre of agents used in preventing UTIs in nursing homes is scarcely documented and the aim of this study was to explore which agents are prescribed for this purpose.</p> <p>Methods</p> <p>We conducted a one-day, point-prevalence study in 44 Norwegian nursing homes during April-May 2006. Nursing home residents prescribed any agent for UTI prophylaxis were included. Information recorded was type of agent and dose, patient age and gender, together with nursing home characteristics. Appropriateness of prophylactic prescribing was evaluated with references to evidence in the literature and current national guidelines.</p> <p>Results</p> <p>The study included 1473 residents. 18% (n = 269) of the residents had at least one agent recorded as prophylaxis of UTI, varying between 0-50% among the nursing homes. Methenamine was used by 48% of residents prescribed prophylaxis, vitamin C by 32%, and cranberry products by 10%. Estrogens were used by 30% but only one third was for vaginal administration. Trimethoprim and nitrofurantoin were used as prophylaxis by 5% and 4%, respectively.</p> <p>Conclusions</p> <p>The agents frequently prescribed to prevent UTIs in Norwegian nursing homes lack documented efficacy including methenamine and vitamin C. Recommended agents like trimethoprim, nitrofurantoin and vaginal estrogens are infrequently used. We conclude that prescribing of prophylactic agents for UTIs in nursing homes is not evidence-based.</p

Antimicrobial resistance monitoring and surveillance in the meat chain: A report from five countries in the European Union and European Economic Area

Background The emergence of antimicrobial resistance (AMR) in zoonotic foodborne pathogens (Salmonella, Campylobacter) and indicator microorganisms (E. coli, enterococci) is a major public health risk. Zoonotic bacteria, resistant to antimicrobials, are of special concern because they might compromise the effective treatment of infections in humans. Scope and approach In this review, the AMR monitoring and surveillance programmes in five selected countries within European Union (EU) and European Economic Area (EEA) are described. The sampling schemes, susceptibility testing for AMR identification, clinical breakpoints (clinical resistance) and epidemiological cut-off values (microbiological resistance) were considered to reflect on the most important variations between and within food-producing animal species, between countries, and to identify the most effective approach to tackle and manage the antimicrobial resistance in the food chain. Key findings and conclusions The science-based monitoring of AMR should encompass the whole food chain, supported with public health surveillance and should be conducted in accordance with ‘Zoonoses Directive’ (99/2003/EC). Such approach encompasses the integrated AMR monitoring in food animals, food and humans in the whole food (meat) chain continuum, e.g. pre-harvest (on-farm), harvest (in abattoir) and post-harvest (at retail). The information on AMR in critically important antimicrobials (CIA) for human medicine should be of particular importance

Antibiotics to outpatients in Norway—Assessing effect of latitude and municipality population size using quantile regression in a cross-sectional study.

High antibiotic consumption rates are associated to high prevalence of antimicrobial resistance. Geographical differences in dispensing rates of antibiotics are frequently analysed using statistical methods addressing the central tendency of the data. Yet, examining extreme quantiles may be of equal or greater interest if the problem relates to the extremes of consumption rates, as is the case for antimicrobial resistance. The objective of this study was to investigate how geographic location (latitude) and municipality population size affect antibiotic consumption in Norway. We analysed all outpatient antibiotic prescriptions (n > 14 000 000) in Norway between 2004 and 2010 using quantile regression. Data were stratified by year, and we aggregated individual data to municipality, county, or latitudinal range. We specified the quantile regression models using directed acyclic graphs and selected the model based on Akaike information criteria. Yearly outpatient antibiotic consumption in Norway varied up to 10‐fold at municipality level. We found geographical variation to depend on the number of inhabitants in a municipality and on latitude. These variables interacted, so that consumption declined with increasing latitude when municipality population sizes were small, but the effect of latitude diminished as the number of inhabitants increased. Aggregation to different levels of spatial resolution did not significantly affect our results. In Norway, outpatient antibiotic dispensing rates decreases with latitude at a rate contingent on municipality population size. Quantile regression analysis provides a flexible and powerful tool to address problems related to high, or low, dispensing rates