Livestock-Associated Methicillin-resistant Staphylococcus aureus (LA-MRSA) has emerged in pigs globally. Pig farms act as a reservoir of LA-MRSA. In the Netherlands, the prevalence of LA-MRSA in slaughter pigs was 99.5% in 2015. Through exposure to animals and dust, farms are at risk for acquiring LA-MRSA. In the Netherlands MRSA colonization in the general population and in hospitals is very low. Strict infection control measures are implemented in hospitals (‘search and destroy’) to prevent spread of MRSA of people who are at risk of being MRSA-positive. With the introduction of LA-MRSA, all people working with living pigs and veal calves are considered as risk for being LA-MRSA positive and are included in the search and destroy program with quarantine and additional diagnostics. Infections with multidrug-resistant microorganisms, including LA-MRSA are a burden for patients, health care staff, and finances of health care institutions.

 The recent adaptation of LA-MRSA to humans in Denmark, and the recently observed unexplained cases of LA-MRSA patients in Dutch hospitals, highlights the need to prevent LA-MRSA transmission. At this moment, there are no intervention measures in pig production to reduce LA-MRSA in pigs. In a pilot microbiome study, we identified several bacterial species negatively associated with colonization of LA-MRSA in piglets. To identify and isolate bacterial strains that will effectively outcompete LA-MRSA when used as a pre-colonization microflora, strain level metagenomics followed by high throughput strain identification will be used. Subsequently these competing strains should be produced and applied nasally as live bacteria in newborn piglets, in order to limit or eradicate LA-MRSA outgrowth in the piglet nasopharynx. Prevention of LA-MRSA colonization will reduce the transmission risk of LA-MRSA from piglets to farm workers through dust. We aim to study the effect of this bacterial inference on transmission of LA-MRSA from pigs to humans by i) identifying competing bacterial species that might be included in a microflora to be used in pigs, ii) studying the efficacy of pre-colonizing piglets, and iii) estimating the risk reduction for MRSA transmission to humans as a result of reduced environmental contamination.

In this project, an interdisciplinary group works together with an industrial partner to identify bacterial species that compete with LA-MRSA for production of a microflora that can be administered to pigs for modulation of the nasal microbiome. The outcome of this project will be a novel intervention procedure based on protecting the piglets for colonization with LA-MRSA by competitive-exclusion.

• dr. A. (Arie) van Nes
• dr. A Fluit
• dr. A.A. (Abel) Vlasblom
• prof. dr. J.A. (Jaap) Wagenaar
• dr. B. (Birgitta) Duim
• dr. A.L. (Aldert) Zomer

• Marjolein Kluytmans-van den Bergh
• Gerard van Eijden

In the Netherlands, there is an ongoing debate regarding environmental health risks of exposures from livestock farming, in particular from swine and poultry farms. Residents of many (new) urban areas, located at close proximity from commercial farming activities, usually less than a few hundreds meters to a few kilometers, may be exposed to potentially harmful infectious and resistant microorganisms, gases, and dust particles containing toxins. There is little scientific information about health risks for neighboring residents of livestock farms, but the available literature suggests several potential community health risks, like zoonoses and respiratory health effects. The overall objective of the VGO study is to investigate whether environmental exposure to livestock farm emissions in the Netherlands poses a health risk among neighbouring residents. 

Project leader of two work packages (Astma/COPD and Data Management). 

• dr. ir. I.M. (Inge) Wouters

Construction workers are at a high risk for developing skin disorders as a result of exposure to a wide variety of allergens and irritants. The social and economic impact of occupational contact dermatitis is high, because prognosis is poor, and changing jobs is sometimes the only option for affected workers. Besides exposure to irritants and allergens, individual susceptibility may influence the risk to develop occupational contact dermatitis. In spite of the impact and high prevalence of contact dermatitis in various occupations, actions to reduce the risk of skin disorders in the construction industry have thus far been restricted to a few hazardous agents. This study investigates risk factors for occupational contact dermatitis in the construction industry at large. New insights in risk factors will be used to develop tools that will help to reduce the burden of skin disease among construction workers. 

This research project investigates the possible impact of global climate change on reproductive health in Arctic and three local European populations. The key questions to be addressed are, first, how may climate change impact on human exposure to widespread environmental contaminants and, second, how may contaminants impact on occurrence of reproductive disorders as sensitive indicators of health.

To provide affirmative answers to these questions the project will

(i) identify and describe mechanisms by which a changing climate may affect the exposure of arctic and other human populations to contaminants through change in chemical use and emissions, delivery to the arctic ecosystem as well as processing within the arctic physical environment and human food chain. This work relies on modeling of existing data.

(ii) expand the existing knowledge database on human exposure to polybrominated diphenylethers, perfluorinated surfactants and phthalates by analyses of 1000 biobanked serum samples collected in the EU FP5 programme INUENDO

(iii) increase the limited knowledge on links between human exposure to contaminants and reproductive health. This work relies on a large existing parent-child-cohort, where a follow-up survey provide new data that are fed into risk assessment

(iv) perform reviews of experimental and epidemiological literature to identify critical reproductive effects and exposure response data for the selected compounds as input to the risk assesment

(v) integrate data on relative climate induced changes in contaminant mobility and distribution and links between contaminant exposure and reproductive health into a risk evaluation providing insight into possible future risk scenarios related to global climate change.

• prof. dr. ir. R.C.H. (Roel) Vermeulen

HLA is a principal candidate gene region for occupational asthma. Recently, HLA-DQ emerged from genome-wide association studies of late-onset asthma. The aim of this study is to further elucidate the role of HLA class II in adult-onset asthma, by taking occupational exposure into account.

Multi-center study on HLA variants, occupational exposure and adult-onset asthma.