The European Parliament has asked EFSA’s Biological Hazards Panel (BIOHAZ) to issue an opinion on the transmission of antimicrobial resistance (AMR) during live animal transport.
The opinion covers ARBs(antimicrobial-resistant bacteria) of public health importance, including foodborne pathogens and indicator bacteria(Salmonella spp, Campylobacter spp., Escherichia coli, Enterococcus spp., MRSA) and on ARGs(antimicrobial resistance genes). The EFSA opinion, delivered to the European Commission along with five other scientific opinions, is intended to assist the ongoing review of animal welfare legislation in the European Union (EU), a cornerstone of the EU’s #FarmtoFork strategy.
Main risk factors for the transmission of antimicrobial resistance
Before loading, animals harbor a specific microbiota with a number of ARBs/ARGs found within or on the surface of the animal at different sites in the organism.
EFSA’s evaluation focused on the change in ARB/ARG ratio at the end of short or long transport (less than or more than 8 h). The first three risk factors identified are more related to the animal, and the last four to the environment. All these factors can be interconnected.
1) The ARB/ARGs status of the microbiota of animals before transport.
If ARBs/ARGs are not present among animals, transmission and contamination of surfaces and transport equipment will not occur. Resistance status before transport depends on all factors that influence the presence of ARB/ARG in animals on farms (EMA and EFSA, 2017).
Another important element is the different level of ARB/ARGs that can be found depending on age (Hoyle et al., 2004; Bastard et al., 2021; Masse et al., 2021) and animal species (EFSA, 2020, 2022; Lynch et al., 2022).
2) Factors affecting the microbiota of animals during transport.
Intrinsic changes in antimicrobial resistance in the individual animal can be induced by selection pressure through the use of antimicrobials prior to the arrival of ARBs.
Other factors that may affect the microbiota of animals during transport include:
- Feed withdrawal (Joat et al., 2021; Mahmood et al., 2007).
- Stress factors (such as animal handling, heat stress, starvation, loading/unloading)
- Environmental conditions (Woldehiwet et al., 1990; Sepulveda and Moeller, 2020)
- General health status of the animal.
3) Factors influencing ARB/ARG shedding by individual animal.
The primary factor for transmission of bacteria (mainly Salmonella and Campylobacter) is fecal-oral transmission (Quintana-Hayashi and Thakur, 2012; Greening et al., 2021).
Animals release ARBs/ARGs with their feces, which can be ingested by other animals on the same transporter or can contaminate the vehicle.
4) Environmental exposure to ARBs/ARGs.
Exposure to ARBs/ARGs in the environment can occur at all the different stages of transport. Residual environmental contamination can cause indirect transmission of ABR/ARG to other groups of animals transported by the same vehicle or coming into contact with the same premises (Quintana-Hayashi and Thakur, 2012). Environmental conditions, such as humidity and temperature, can affect ARB survival in the environment.
ARBs could also be transmitted through the air, such as attached to dust particles from dried feces, skin particles, and feathers.
5) Exposure to other animals that carry and/or spread ARB/ARG.
Animals can be exposed to ARBs/ARGs carried by other animals, either shed or present on their skin or mucosal surfaces via bacteria-containing materials such as feces, exhaust air, saliva, urine, and milk.
It is a major source of contamination for other animals during transport. The stocking density and division into groups or compartments may influence the likelihood of ARB/ARG transmission among animals (EFSA, 2010)
6) Environmental and transportation conditions
Unfavorable environmental conditions (high temperature/humidity) are associated with the survival and multiplication rate of bacteria in the environment, including ARBs/ARGs; humidity and warm temperatures can increase the survival rate and multiplication of bacteria in the environment. Poor ventilation increases the concentration of bacteria in the air.
7) Duration of transportation (travel/transit)
The duration of transport has a potentially significant impact on both bacterial multiplication and animal exposure to ARB/ARG bacteria. Also because of their in the environment (Padalino et al., 2021)
Attenuation measurements
In light of the above, EFSA has identified some measures to mitigate the risk factors associated with AMR transmission during animal transport.
Mitigation measures were ranked according to their likely effectiveness:
- Any measures that improve animal health and welfare and/or biosecurity immediately before and during transport–e.g., good husbandry and handling practices in preparation for transport, segregation of animals (by species, stage of production, or age), hygiene (of vehicles and cages, surfaces, and equipment), climatic comfort–have a high likelihood of mitigating the risk of AMR transmission,
- followed by reducing the density of animals and the number of animals in contact, as well as avoiding the transport of sick animals,
- On the other hand, the use of bedding of various types can have both positive and negative effects on the likelihood of ARB/ARG transmission.
One Health
The impact of this assessment goes beyond animal health and welfare, as many antibiotic-resistant bacteria can be transmitted from animals to humans. EFSA has also launched a public consultation on the approach to be taken in upcoming scientific opinions on farm animal welfare, expected by March 2023.
Notes
The limitations of the EFSA assessment are found in the substantial lack of specific studies on the spread of antimicrobial resistance among animals during transport. Reducing antibiotic use in animal husbandry therefore remains a public health priority and can be achieved with solutions (e.g., Algatan) already successfully tested in Italy itself (Dongo, Della Penna, 2020).
Bibliography
EFSA (European Food Safety Authority), Koutsoumanis K, Allende A, Alvarez-Ordonez A, Bolton D,Bover-Cid A,Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M,Ru G, Simmons M, Skandamis P, Suffredini E, Arguello-Rodrıguez H,Dohmen W,Magistrali C, Padalino B, Tenhagen B, Threlfall J, Garcıa-Fierro R, Guerra E, Liebana E, Stella P,Peixe L,2022. Transmission of antimicrobial resistance (AMR) during animal transport EFSA Journal 2022;20( 10):7586, 83 pp. https://doi.org/10.2903/j.efsa.2022.7586
Bastard J, Haenni M, Gay E, Glaser P, Madec JY, Temime L and Opatowski L, 2021. Drivers of ESBL-producing Escherichia coli dynamics in calf fattening farms: a modelling study. One Health, 12, 100238
Beloeil PA, Fravalo P, Fablet C, Jolly JP, Eveno E, Hascoet Y, Chauvin C, Salvat G and Madec F, 2004. Risk factors for Salmonella enterica subsp.enterica shedding by market-age pigs in French farrow-to-finish herds. Preventive Veterinary Medicine, 63, 103-120;
Dongo D, Della Penna A, 2020. Animal husbandry, algae and microalgae to prevent antibiotic use. Algatan. GIFT (Great Italian Food Trade)
EMA and EFSA(European Medicines Agency and European Food Safety Authority), 2017. EMA and EFSA JointScientific Opinion on measures to reduce the need to use antimicrobial agents in animal husbandry in the European Union, and the resulting impacts on food safety (RONAFA). EFSA Journal 2017; 15:4666, 245 pp;
EFSA(European Food Safety Authority), Martino L, Aiassa E, Halldorsson TI, Koutsoumanis PK, Naegeli H, Baert K,Baldinelli F, Devos Y, Lodi F, Lostia A, Manini P, Merten C, Messens W, Rizzi V, Tarazona J, Titz A and Vos S,2020. Draft framework for protocol development for EFSA’s scientific assessments. EFSA supporting publication 2020: EN-1843, 46 pp
EFSA(European Food Safety Authority), 2010. Analysis of the baseline survey on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in holdings with breeding pigs, in the EU, 2008, Part B: factors associated with MRSA contamination of holdings; on request from the European Commission. EFSA Journal 2010; 8:1597, 67 pp
Greening SS, Zhang J, Midwinter AC, Wilkinson DA, Fayaz A, Williamson DA, Anderson MJ, Gates MC and French NP, 2021. Transmission dynamics of antimicrobial resistant Campylobacter jejuni lineage in New Zealand’s commercial poultry network. Epidemics, 37, 100521
Hoyle DV, Knight HI, Shaw DJ, Hillman K, Pearce MC, Low JC, Gunn GJ and Woolhouse ME, 2004. Acquisition and epidemiology of antibiotic-resistant Escherichia coliin a cohort of newborn calves. The Journal of Antimicrobial Chemotherapy, 53, 867-871
Lynch H, Franklin-Hayes P, Koolman L, Egan J, Gutierrez M, Byrne W, Golden O, Bolton D, Reid P, Coffey A, LuceyB, O’Connor L, Unger K and Whyte P, 2022. Prevalence and levels of Campylobacterin broiler chicken batchesand carcasses in Ireland in 2017-2018. International Journal of Food Microbiology, 372, 109693
Massé J, Lardé H, Fairbrother JM, Roy JP, Francoz D, Dufour S and Archambault M, 2021. Prevalence of antimicrobial resistance and characteristics of Escherichia coliisolates from fecal and manure pit samples waveiry farms in the province of Quebec, Canada. Frontiers in Veterinary Science, 8, 654125
Joat NN, Khan S and Chousalkar K, 2021. Understanding the effects of intramuscular injection and feed withdrawal on Salmonella Typhimurium shedding and gut microbiota in pullets. Journal of Animal Science and Biotechnology, 12, 78
Jones EM, Snow LC, Carrique-Mas JJ, Gosling RJ, Clouting C and Davies RH, 2013. Risk factors for antimicrobial resistance in Escherichia colifound in GB turkeyflocks. Veterinary Record, 173, 422
Mahmood S, Mehmood S, Ahmad F and Kausar A, 2007. Effects of feed restriction during starter phase onsubsequent growth performance, dressing percentage, relative organ weights and immune response ofbroilers. Pakistan Veterinary Journal, 27, 137-141.
Padalino B, Cirone F, Zappaterra M, Tullio D, Ficco G, Giustino A, Ndiana LA and Pratelli A, 2021b. Factors affecting the development of bovine respiratory disease: a cross-sectional study in beef steers shipped from France to Italy. Frontiers in Veterinary Science, 8, 62789
Sepulveda J and Moeller AH, 2020. The effects of temperature on animal gut microbiomes. Frontiers in Microbiology, 11, 384
Quintana-Hayashi MP and Thakur S, 2012. Longitudinal study of the persistence of antimicrobial-resistant Campylobacter strains in distinct swine production systems on farms, at slaughter, and in the environment. Applied and Environmental Microbiology, 78, 2698-2705
Woldehiwet Z, Mamache B and Rowan TG, 1990. The effects of age, environmental temperature and relativehumidity on the bacterialflora of the upper respiratory tract in calves. The British Veterinary Journal, 146, 211-218
Graduated in industrial biotechnology and passionate about sustainable development.
