Emergence of antimicrobial resistance (AMR) in the animal reservoir forms a risk for human health. The use of antimicrobials in animals is the major cause of development of AMR in bacteria in animals. In the 1990s, the use of antimicrobials in animals, particularly as a growth promoter, led to alarming levels of AMR in many countries. This paper analyses the emergence of AMR in Denmark in terms of contributing factors that formed fertile ground from which AMR could develop. New technologies in combination with scientific unknowns led to the unexpected development of cross-resistance and an uncertainty about transmission to and risk for humans. Conflict of interests and varying susceptibility to risk between agriculture, health and commercial stakeholders complicated intervention. In addition, unintended economic incentives from old legislation resulted in a situation where the use of antimicrobials in general was stimulated. Complications of alarming high levels of AMR in animals, and a general discontent about this situation (including with farmers and vets) demanded a solution. National surveillance in DANMAP involving all stakeholders from the farm-to-fork food chain was setup to counteract scientific unknowns and conflicts of interest; new legislation was developed; and unintended economic incentives reduced. The current analysis may help to better understand the AMR problem in general and what may be done to counteract it.
Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and ScienceVol. 11, No. S1 DetectionOpen AccessDetecting Bioterrorism: How to Detect the Unexpected?Peter R. WielingaPeter R. WielingaSearch for more papers by this authorPublished Online:24 Aug 2013https://doi.org/10.1089/bsp.2013.0863AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail Terrorism works because its actions happen when and where they are not expected. In that sense, it works like a natural disease outbreak: One cannot predict when it will come, who it will affect, or which disease will strike again. We have learned to live with this uncertainty and risk and found ways to protect ourselves against such disease outbreaks. To do so, most, if not all, countries in the world have active surveillance programs for a list of the most endemic diseases.Bioterrorism is a term used for terrorism using biological weapons, such as infectious diseases or biological toxins. Having normal surveillance programs in place, we have the necessary tools to detect and act against many biological weapons and diseases that may be used by terrorists. However, some diseases are not included in the active surveillance programs of many countries, because they do not cause problems in the specific country, either because they never have been endemic or they have been eradicated in the past. Two important infectious diseases for which this is the case are anthrax and botulism, caused by Bacillus anthracis and Clostridium botulinum, respectively. Both are zoonotic and may live in all kinds of animals, including the animals used for consumption. In addition, these infectious diseases form spores that are difficult to kill and easily survive standard food treatments. This puts these pathogens at the top of the list of most feared diseases and biological weapons. However, these diseases have been dealt with efficiently in many countries in the past and have not caused major outbreaks in many western countries recently. This has allowed some countries to loosen the surveillance and research on these diseases. Because of the anthrax letters in the United States, the failed anthrax attack in the streets of Japan, and the increased global will to have preventive tools in place for possible terror attacks, the research into anthrax and botulism, as well as several other potential biological weapons, has been revived.The articles in this section deal with methods to detect anthrax and botulism in settings that are relevant when used in terrorist actions. They describe several new and improved methods and discuss approaches to best look and sample for the diseases. Specifically, the use of whole-genome sequencing techniques deserves attention, as it will be an important tool in future bioterrorism and also normal surveillance research. Whole-genome sequencing can be used to detect any microorganism in a sample with 1 analysis, thus making it truly a technique to detect the unexpected. It can be foreseen that the introduction of whole-genome sequencing, not only in the field of bioterrorism, but also in the fields of public human health and animal health or as a diagnostic tool used by hospitals and general practitioners, will greatly advance treatment of infectious diseases and human health.FiguresReferencesRelatedDetails Volume 11Issue S1Sep 2013 InformationCopyright 2013, Mary Ann Liebert, Inc.To cite this article:Peter R. Wielinga.Detecting Bioterrorism: How to Detect the Unexpected?.Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science.Sep 2013.S123-S123.http://doi.org/10.1089/bsp.2013.0863creative commons licensePublished in Volume: 11 Issue S1: August 24, 2013PDF download
Food Safety is at the center of One Health. Many, if not most, of all important zoonoses relate in some way to animals in the food production chain. Therefore, the food becomes an important vehicle for many, but not all, of these zoonotic pathogens. One of the major issues in food safety over the latest decennia has been the lack of cross-sectoral collaboration across the food production chain. Major food safety events have been significantly affected by the lack of collaboration between the animal health, the food control, and the human health sector. Examples range from BSE and E. coli outbreaks over dioxin crises to intentional melamine contamination. One Health formulates clearly both the need for and the benefit of cross-sectoral collaboration. In this chapter, we will focus on the human health risk related to zoonotic microorganisms present both in food animals and food from these animals, and typically transmitted to humans through food. We focus on these issues because they are very important in relation to the human disease burden, but also because this is the area where some experience of cross-sectoral collaboration already exist. Food related zoonoses can be separated in three major classes: parasites, bacteria, and viruses. While parasites often relate to very specific animal hosts and contribute significantly to the human disease burden, virus have often been related to major, well-published global outbreaks, e. g. SARS and avian-and swine-influenza. The bacterial zoonoses on the other hand often result in sporadic, but very wide-spread disease cases, resulting in a major disease burden in all countries, e. g. Salmonella and Campylobacter. Next to these traditional zoonotic problems, the use of antimicrobials in (food) animals has also caused the emergence of antimicrobial resistant (AMR) zoonotic bacteria. It is important to realize the difference in the nature of disease epidemiology, as well as, in society's reaction to these diseases in different socio-economic settings. Some diseases have global epidemic-or pandemic-potential, resulting in dramatic action from international organizations and national agricultural-and health authorities in most countries, for instance as was the case with avian influenza. Other diseases relate to the industrialized food production chain and have been-in some settings-dealt with efficiently through farm-to-fork preventive action in the animal sector, e. g. Salmonella. Finally, an important group of zoonotic diseases are 'neglected diseases' in poor settings, while they have been basically eradicated in affluent economies through vaccination and culling policies in the animal sector, e. g. Brucella.
ABSTRACT Q fever, caused by Coxiella burnetii , is a zoonosis with a worldwide distribution. A large rural area in the southeast of the Netherlands was heavily affected by Q fever between 2007 and 2009. This initiated the development of a robust and internally controlled multiplex quantitative PCR (qPCR) assay for the detection of C. burnetii DNA in veterinary and environmental matrices on suspected Q fever-affected farms. The qPCR detects three C. burnetii targets ( icd , com1 , and IS 1111 ) and one Bacillus thuringiensis internal control target ( cry1b ). Bacillus thuringiensis spores were added to samples to control both DNA extraction and PCR amplification. The performance of the qPCR assay was investigated and showed a high efficiency; a limit of detection of 13.0, 10.6, and 10.4 copies per reaction for the targets icd , com1 , and IS 1111 , respectively; and no cross-reactivity with the nontarget organisms tested. Screening for C. burnetii DNA on 29 suspected Q fever-affected farms during the Q fever epidemic in 2008 showed that swabs from dust-accumulating surfaces contained higher levels of C. burnetii DNA than vaginal swabs from goats or sheep. PCR inhibition by coextracted substances was observed in some environmental samples, and 10- or 100-fold dilutions of samples were sufficient to obtain interpretable signals for both the C. burnetii targets and the internal control. The inclusion of an internal control target and three C. burnetii targets in one multiplex qPCR assay showed that complex veterinary and environmental matrices can be screened reliably for the presence of C. burnetii DNA during an outbreak.
A real-time PCR method for detection and typing of BoNT-producing Clostridia types A, B, E, and F was developed on the framework of the European Research Project "Biotracer". A primary evaluation was carried out using 104 strains and 17 clinical and food samples linked to botulism cases. Results showed 100% relative accuracy, 100% relative sensitivity, 100% relative specificity, and 100% selectivity (inclusivity on 73 strains and exclusivity on 31 strains) of the real-time PCR against the reference cultural method combined with the standard mouse bioassay. Furthermore, a ring trial study performed at four different European laboratories in Italy, France, the Netherlands, and Sweden was carried out using 47 strains, and 30 clinical and food samples linked to botulism cases. Results showed a concordance of 95.7% among the four laboratories. The reproducibility generated a relative standard deviation in the range of 2.18% to 13.61%. Considering the high level of agreement achieved between the laboratories, this real-time PCR is a suitable method for rapid detection and typing of BoNT-producing Clostridia in clinical, food and environmental samples and thus support the use of it as an international standard method.
A next frontier of the global food safety agenda has to consider a broad spectrum of bio-risks, such as accidental and intentional contaminations in the food and feed chain. In this article, the background for the research needs related to biotraceability and response to bioterrorism incidents are outlined. Given the current scale of international trade any response need to be considered in an international context. Biotraceability (e.g. the ability to use downstream information to point to processes or within a particular food chain that can be identified as the source of undesirable agents) is crucial in any food-born outbreak and particular in the response to bioterrorism events. In the later case, tested and proven biotraceability improves the following: (i) international collaboration of validated tracing tools and detection methods, (ii) multi-disciplinary expertise and collaboration in the field of food microbiology and conceptual modeling of the food chain, (iii) sampling as a key step in biotracing (iv) optimized sample preparation procedures, including laboratory work in Biosafety level 3 (BSL-3) laboratories, (v) biomarker discovery for relevant tracing and tracking applications, and (vi) high-throughput sequencing using bio-informatic platforms to speed up the characterization of the biological agent. By applying biotraceability, the response phase during a bioterrorism event may be shortened and is facilitated for tracing the origin of biological agent contamination.
The DNA extraction efficiency from milk, whey, soy, corn gluten meal, wheat powders and heat-treated corn grain that were spiked with Bacillus anthracis and Bacillus thuringiensis spores was determined. Two steps were critical: lysis of the spores and binding of the free DNA to the DNA binding magnetic beads in the presence of the interfering powders. For the guanidine-thiocyanate based Nuclisens lysis buffer from Biomerieux we found that between 15 and 30% of the spores survived the lysis step. As most lysis buffers in DNA/RNA extraction kits are guanidine based it is likely that other lysis buffers will show a similar partial lysis of the Bacillus spores. Our results show that soybean flour and wheat flour inhibited the DNA extraction process strongest, leading to unreliable DNA extractions when using too much of the matrix. For corn gluten meal, heat-treated corn grain and milk powders, DNA extraction efficiencies in the presence of 100mg and 10mg of powder resulted in 70%–95% reduced DNA recoveries. The inhibition was, however, reliable and intermediate compared to the inhibition by soy and wheat. Whey powder had the lowest inhibitory effect on DNA-extraction efficiency and recoveries of 70–100% could be reached when using 10mg of powder. The results show that reducing the amount of matrix leads to better DNA-extraction efficiencies, particularly for strongly inhibiting powders such as soy and wheat. Based on these results, a standard protocol to directly isolate DNA from micro-organisms present in complex matrixes such as food and feed powders was designed.
The rapid technological development in the field of parallel sequencing offers new opportunities when tracing and tracking microorganisms in the food and feed chain. If a bioterror organism is deliberately spread it is of crucial importance to get as much information as possible regarding the strain as fast as possible to aid the decision process and select suitable controls, tracing and tracking tools. A lot of efforts have been made to sequence multiple strains of potential bioterror organisms so there is a relatively large set of reference genomes available. This study is focused on how to use parallel sequencing for rapid phylogenomic analysis and screen for genetic modifications. A bioinformatic methodology has been developed to rapidly analyze sequence data with minimal post-processing. Instead of assembling the genome, defining genes, defining orthologous relations and calculating distances, the present method can achieve a similar high resolution directly from the raw sequence data. The method defines orthologous sequence reads instead of orthologous genes and the average similarity of the core genome (ASC) is calculated. The sequence reads from the core and from the non-conserved genomic regions can also be separated for further analysis. Finally, the comparison algorithm is used to visualize the phylogenomic diversity of the bacterial bioterror organisms Bacillus anthracis and Clostridium botulinum using heat plot diagrams.
Bacillus anthracis is closely related to the endospore forming bacteria Bacillus cereus and Bacillus thuringiensis. For accurate detection of the life threatening pathogen B. anthracis, it is essential to distinguish between these three species. Here we present a novel multiplex real-time PCR for simultaneous specific identification of B. anthracis and discrimination of different B. anthracis virulence types. Specific B. anthracis markers were selected by whole genome comparison and different sets of primers and probes with optimal characteristic for multiplex detection of the B. anthracis chromosome, the B. anthracis pXO1 and pXO2 plasmids and an internal control (IC) were designed. The primer sets were evaluated using a panel of B. anthracis strains and exclusivity was tested using genetically closely related B. cereus strains. The robustness of final primer design was evaluated by laboratories in three different countries using five different real-time PCR thermocyclers. Testing of a panel of more than 20 anthrax strains originating from different locations around the globe, including the recent Swedish anthrax outbreak strain, showed that all strains were detected correctly.
Rapid and specific detection of botulinum neurotoxin (BoNT) producing Clostridia is a priority for public health authorities, in case of both natural and intentional botulism outbreaks. This study reports on the evaluation of a detection system based on the GeneDisc Cycler designed for simultaneously testing the bont/A, bont/B, bont/E and bont/F genes encoding for the botulinum neurotoxins types A, B, E and F. BoNT-producing Clostridia (n = 102) and non-BoNT-producing bacteria (n = 52) isolated from clinical, food and environmental samples were tested using this macro-array and results were compared to the reference lethality test on mice. The bont genes were correctly detected in all C. botulinum type A, B, E and F strains available, as well as in toxigenic C. baratii type F and toxigenic C. butyricum type E. No cross reactivity was observed with non human-toxigenic bacteria, C. botulinum types C, D and G. The identification of the bont genotype using the macro-array was correlated to toxino-typing of the BoNTs as determined by the mouse bioassay. An "evaluation trial" of the GeneDisc array performed blind in four European laboratories with 77 BoNT-producing Clostridia as well as 10 food and clinical samples showed that the developed macro-array is specific and reliable for identifying BoNT/A-, BoNT/B-, BoNT/E- and BoNT/F-producing clostridial strains and for screening naturally contaminated food and fecal samples. The test is robust, has a low detection limit (c.a. 5 to 50 genome copies in the PCR reaction microwell) and is promising for monitoring BoNT-producing Clostridia in different kinds of samples including food and clinical samples.
Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus , the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp . related to the typhus group were also detected in I. ricinus . The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica , unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica , and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.
OBJECTIVE:To investigate the percentage of ticks infected with Borrelia burgdorferi on the Dutch North Sea island of Ameland, and the risk of developing Lyme disease following tick bite on the island.DESIGN:Prospective, observational.METHOD:Ticks were collected from patients who visited a general practitioner and were tested for the DNA of B. burgdorferi. After 6 months the patients were interviewed by phone using a standardised questionnaire.RESULTS:From 2004-2006, 216 ticks were collected from 167 persons. Most ticks were removed within 24 hours. In 44 ticks (20.4%) B. burgdorferi DNA was detected. Follow up information was available on 146 persons, 41 (28.1%) of whom had been bitten by a Borrelia-positive tick. None of the persons developed a typical erythema migrans. From the 13 persons (9%) reporting a non-specific redness of the skin (diameter less than 5 cm) at the site of the tick bite, 5 had been bitten by a positive tick and 8 by a negative tick. One patient bitten by a positive tick reported systemic symptoms related to Lyme borreliosis, namely fatigue, perspiration and joint ache, without local redness.CONCLUSION:The probability of developing Lyme borreliosis was low even though a relatively large percentage of the ticks collected were positive for B. burgdorferi. This is probably connected to the fact that in the majority of cases the tick had been removed within 24 hours.
The protozoan parasite Cryptosporidium is found world-wide and can cause disease in both humans and animals. To study the zoonotic potential of Cryptosporidium in The Netherlands we isolated this parasite from the faeces of infected humans and cattle and genotyped those isolates for several different markers. The overall genotyping results showed: for humans isolates, 70% Cryptosporidium hominis, 19% Cryptosporidium parvum, 10% a combination of C. hominis and C. parvum, and 1% Cryptosporidium felis; and for cattle isolates 100% C. parvum. Analysis of the genetic variants detected for the HSP70, ML1 and GP60 markers showed: for human isolates, one C. hominis and two C. parvum variants (C. parvum and C. parvum NL) for HSP70, one C. hominis and five C. parvum variants (C1, C2, C3, and C2 NL1 and C2 NL2) for ML1, four C. hominis (mainly IbA10G2) and four C. parvum variants (mainly IIaA15G2R1) for GP60; and the cattle isolates only C. parvum (not C. parvum NL1) for HSP70, C1 and C2 for ML1, and 17 different IIa sub-types (mainly IIaA15G2R1) for GP60. Molecular epidemiological analysis of the human data showed a C. hominis peak in autumn. The majority (80%) of the human cases were children aged between 0 and 9 years and >70% of these were caused by C. hominis. Patients >25 years of age were infected mainly with C. parvum. We conclude that C. hominis IbA10G2 is found at high frequencies in autumn in humans and not in cattle. The high prevalence of C. parvum IIaA15G2R1 in both humans and cattle indicates that cattle may be a reservoir for this sub-type in The Netherlands.
We report the finding of Babesia EU1 and Babesia microti in Ixodes ricinus ticks in the Netherlands. During 5 years of surveillance between 2003 and 2007, 1488 ticks were collected in a dune forest area near the North Sea and were screened for Babesia infections. In 17 ticks, DNA of the protozoan parasite genus Babesia was detected using a Babesia-specific 18S rRNA polymerase chain reaction. Further, reverse line blot analysis and DNA sequence analysis showed that 13 of these ticks carried Babesia EU1, two ticks carried B. microti, and one tick carried B. divergens. This study shows that the human pathogenic species Babesia EU1 and B. microti can complete their life cycle in the Netherlands.
cGMP secretion from cells can be mediated by ATP-binding cassette (ABC) transporters ABCC4, ABCC5, and ABCC11. Indirect evidence suggests that ABCC4 and ABCC5 contribute to cGMP transport by erythrocytes. We have re-investigated the issue using erythrocytes from wild-type and transporter knockout mice. Murine wild-type erythrocyte vesicles transported cGMP with an apparent Km that was 100-fold higher than their human counterparts, the apparent Vmax being similar. Whereas cGMP transport into human vesicles was efficiently inhibited by the ABCC4-specific substrate prostaglandin E1, cGMP transport into mouse vesicles was inhibited equally by Abcg2 and Abcc4 inhibitors/substrates. Similarly, cGMP transport into vesicles from Abcc4-/- and Abcg2-/- mice was 42% and 51% of that into wild-type mouse vesicles, respectively, whereas cGMP transport into vesicles from Abcc4(-/-)/Abcg2(-/-) mice was near background. The knockout mice were used to show that Abcg2-mediated cGMP transport occurred with lower affinity but higher Vmax than Abcc4-mediated transport. Involvement of Abcg2 in cGMP transport by Abcc4-/- erythrocyte vesicles was supported by higher transport at pH 5.5 than at pH 7.4, a characteristic of Abcg2-mediated transport. The relative contribution of ABCC4/Abcc4 and ABCG2/Abcg2 in cGMP transport was confirmed with a new inhibitor of ABCC4 transport, the protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride.