Experimental Simulation of the Effects of an Initial Antibiotic Treatment on a Subsequent Treatment after Initial Therapy Failure

General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Received: 24 October 2013; in revised form: 23 January 2014 / Accepted: 29 January 2014 / Published: 17 February 2014 Abstract: Therapy failure of empirical antibiotic treatments prescribed by primary care physicians occurs commonly. The effect of such a treatment on the susceptibility to second line antimicrobial drugs is unknown. Resistance to amoxicillin was rapidly induced or selected in E. coli at concentrations expected in the patient's body. Strains with reduced susceptibility outcompeted the wild-type whenever antibiotics were present, even in low concentrations that did not affect the growth rates of both strains. Exposure of E. coli to amoxicillin caused moderate resistance to cefotaxime. The combined evidence suggests that initial treatment by amoxicillin has a negative effect on subsequent therapy with beta-lactam antibiotics

Effects of Therapeutical and Reduced Levels of Antibiotics on the Fraction of Antibiotic-Resistant Strains of Escherichia coli

Development of antibiotic resistance in the microbiota of farm animals and spread of antibiotic-resistant bacteria in the agricultural sector not only threaten veterinary use of antibiotics, but jeopardize human health care as well. The effects of exposure to antibiotics on spread and development of antibiotic resistance in Escherichia coli from the chicken gut were studied. Groups of 15 pullets each were exposed under strictly controlled conditions to a 2-day course of amoxicillin, oxytetracycline, or enrofloxacin, added to the drinking water either at full therapeutic dose, 75% of that, or at the carry-over level of 2.5%. During treatment and for 12 days afterwards, the minimal inhibitory concentration (MIC) for the applied antibiotics of E. coli strains isolated from cloacal swabs was measured. The full therapeutic dose yielded the highest percentage of resistant strains during and immediately after exposure. After 12 days without antibiotics, only strains from chickens that were given amoxicillin were significantly more often resistant than the untreated control. Strains isolated from pullets exposed to carry-over concentrations were only for a few days more often resistant than those from the control. These results suggest that, if chickens must be treated with antibiotics, a short intensive therapy is preferable. Even short-term exposure to carry-over levels of antibiotics can be a risk for public health, as also under those circumstances some selection for resistance takes place

Evaluation of the application for a new alternative processing method for animal by-products of Category 3 material (ChainCraft B.V.)

EFSA received an application from the Dutch Competent Authority, under Article 20 of Regulation (EC) No 1069/2009 and Regulation (EU) No 142/2011, for the evaluation of an alternative method for treatment of Category 3 animal by‐products (ABP). It consists of the hydrolysis of the material to short‐carbon chains, resulting in medium‐chain fatty acids that may contain up to 1% hydrolysed protein, for use in animal feed. A physical process, with ultrafiltration followed by nanofiltration to remove hazards, is also used. Process efficacy has been evaluated based on the ability of the membrane barriers to retain potential biological hazards present. Small viruses passing the ultrafiltration membrane will be retained at the nanofiltration step, which represents a Critical Control Point (CCP) in the process. This step requires the Applicant to validate and provide certification for the specific use of the nanofiltration membranes used. Continuous monitoring and membrane integrity tests should be included as control measures in the HACCP plan. The ultrafiltration and nanofiltration techniques are able to remove particles of the size of virus, bacteria and parasites from liquids. If used under controlled and appropriate conditions, the processing methods proposed should reduce the risk in the end product to a degree which is at least equivalent to that achieved with the processing standards laid down in the Regulation for Category 3 material. The possible presence of small bacterial toxins produced during the fermentation steps cannot be avoided by the nanofiltration step and this hazard should be controlled by a CCP elsewhere in the process. The limitations specified in the current legislation and any future modifications in relation to the end use of the product also apply to this alternative process, and no hydrolysed protein of ruminant origin (except ruminant hides and skins) can be included in feed for farmed animals or for aquaculture

Sickle cell trait (HbAS) and stunting in children below two years of age in an area of high malaria transmission

<p>Abstract</p> <p>Background</p> <p>While the protective effects of sickle cell trait (HbAS) against severe malaria and the resulting survival advantage are well known, the impact on the physical development in young children remains unclear. This study was aimed to investigate the relationship between HbS carriage and stunting in children below two years of age in a cohort from the Ashanti Region, Ghana.</p> <p>Methods</p> <p>1,070 children were recruited at three months of age and followed-up for 21 months with anthropometric measurements performed every three months. Incidence rate ratios with 95% confidence intervals were calculated by Poisson regression to estimate the association of β-globin genotypes with the number of malaria episodes. Odds ratios (OR) were calculated for the association between the occurrence of β-globin genotypes and/or malaria episodes and stunting. The age-dependent between-group and within-group effects for the β-globin genotypes were assessed by population-averaged models estimated by generalized estimation equation with autoregressive correlation structure.</p> <p>Results</p> <p>Analyses showed a significantly lower age-dependent risk of stunting (OR 0.56; 95% CI 0.33–0.96) in carriers of the HbAS genotype (n = 102) in comparison to those with HbAA (n = 692). This effect was restricted to children who experienced malaria episodes during the observation period suggesting that the beneficial effect of the β-globin HbS variant on the incidence of stunting is closely linked to its protection from mild malaria episodes.</p> <p>Conclusion</p> <p>The lower risk of chronic malnutrition in early childhood, mediated by protection against mild malaria episodes, may contribute to the survival advantage of HbAS carriers in areas of high malaria transmission.</p