Insights into Livestock-Related Microbial Concentrations in Air at Residential Level in a Livestock Dense Area

Abstract

Microbial air pollution from livestock farms has raised concerns regarding public health. Little is known about airborne livestock-related microbial levels in residential areas. We aimed to increase insights into this issue. Air measurements were performed in 2014 and 2015 at 61 residential sites in The Netherlands. Quantitative-PCR was used to assess DNA concentrations of selected bacteria (commensals: Escherichia coli and Staphylococcus spp.; a zoonotic pathogen: Campylobacter jejuni) and antimicrobial resistance (AMR) genes (tetW, mecA) in airborne dust. Mixed models were used to explore spatial associations (temporal adjusted) with livestock-related characteristics of the surroundings. DNA from commensals and AMR genes was detectable even at sites furthest away from farms (1200 m), albeit at lower levels. Concentrations, distinctly different between sites, were strongly associated with the density of farms in the surroundings especially with poultry and pigs. C. jejuni DNA was less prevalent (42% of samples positive). Presence of C. jejuni was solely associated with poultry (OR: 4.7 (95% CI: 1.7–14), high versus low poultry density). Residential exposure to livestock-related bacteria and AMR genes was demonstrated. Identified associations suggest contribution of livestock farms to microbial air pollution in general and attribution differences between farm types. This supports the plausibility of recent studies showing health effects in relation to residential proximity to farms.

Comparison of culturable antibiotic-resistant bacteria in polluted and non-polluted air in Beijing, China

“…Here, the quantity and composition of culturable airborne bacteria in the ambient air along with their antibiotic resistance patterns in polluted and non-polluted weathers were surveyed in Beijing. Many studies including airborne bacteria have been carried out in different environments in the past (Cao et al, 2014;de Rooij et al, 2019;Fang et al, 2006Fang et al, , 2007Gao et al, 2018;He et al, 2017;Xie et al, 2019). Yet this is the first observation of the existence and composition analysis of culturable antibiotic-resistant bacteria in the ambient air from polluted and non-polluted weather conditions in Beijing using bacterial culture Fig.…”

Spatial Effects of Livestock Farming on Human Infections With Shiga Toxin‐Producing Escherichia coli O157 in Small but Densely Populated Regions: The Case of the Netherlands

“…The last steps involved the spatial regression analysis and calculation of the population attributable fraction (PAF). We used the statistical software environment R (version 3.6.0) (RCT, 2015) and several R packages and functions for data processing and analysis (Arya et al, 2015;Bates et al, 2019;Bivand et al, 2019;De Jonge & Houweling, 2019;Grolemund & Wickham, 2011;Keitt, 2010;Neuwirth, 2015;Pebesma, 2019;Pebesma, Bivand, Racine, et al, 2019;Pebesma, Bivand, Rowlingson, et al, 2019;R-Core, 2017;Rue, 2019;Wickham, 2019;Wickham, Averick, et al, 2019;Wickham, Francois, et al, 2019;). An overview is provided in supporting information Table S1.…”

“…This could be tested with different methods, of which examples are: (i) spatial regression analysis to determine the probability of exposure (Elson et al, 2018; Friesema et al, 2011; ÓHaiseadha et al, 2017) or (ii) classical case–control studies including relevant spatial variables to determine the importance of particular types of exposure (e.g. number of animals/km 2 ) (de Rooij et al, 2019).…”

A Review of Potential Public Health Impacts Associated With the Global Dairy Sector

“…Residential exposure to livestock‐related bacteria and AMR genes (i.e., tetW and mecA) was recently demonstrated through air measurements at residential sites in the Netherlands (de Rooij, Hoek, et al, ). Specifically, AMR genes were detected in bioaerosols at sites up to 1200 meters away from livestock farms (de Rooij, Hoek, et al, ). However, there are still knowledge gaps surrounding the potential transmission routes between dairy cattle, humans, and the environment (Burgess & French, ).…”

“…Antibiotic‐resistant bacteria from livestock operations (e.g., beef, dairy, and pig) can also become airborne, especially on high intensity farms or confined feed lots (Chapin et al, ; de Rooij et al, ; McEachran et al, ; Navajas‐Benito et al, ). Residential exposure to livestock‐related bacteria and AMR genes (i.e., tetW and mecA) was recently demonstrated through air measurements at residential sites in the Netherlands (de Rooij, Hoek, et al, ). Specifically, AMR genes were detected in bioaerosols at sites up to 1200 meters away from livestock farms (de Rooij, Hoek, et al, ).…”