Editorial: The Role of Environmental Reservoirs in Campylobacter-Mediated Infection

Abstract

Editorial on the Research TopicThe Role of Environmental Reservoirs in Campylobacter-Mediated Infection Campylobacteriosis is a food-borne infection caused mainly by Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli). Thermophilic campylobacters are considered the foremost causative agents of bacterial gastroenteritis worldwide and campylobacteriosis represents an important public health problem with numerous socio-economic impacts. Since 2015, approximately 230,000 cases have been reported annually in Europe (Hansson et al., 2018). C. jejuni and C. coli colonize the digestive tract of multiple animal reservoirs such as birds, sheep, cattle, and pigs, with chicken considered as the main source of human infection in many countries. Yet, epidemiological information regarding the role of other putative disease reservoirs, such as wildlife and environment (e.g. soil and water), in disease transmission is limited.Although Campylobacter can grow only inside the animal host, these bacteria can develop survival strategies by adaptation to different environmental stresses such as fluctuations of oxygen, temperature, biotic interactions, and starvation (Mouftah et al., 2021b). Moreover, the biofilm formation and the interaction with other bacteria also affects the bacterial survival outside the host. Studying the biology of Campylobacter in different environments may provide a better understanding of the infectivity of surviving bacteria to human.The review by Kim et al. focused on molecular mechanisms involved in Campylobacter resistance to adverse environmental conditions, such as acid (e.g. ATR initiation, chaperone proteins DnaK and GroEL, and rpoS gene) and thermal stress (e.g. cold shock protein CspA), high osmolarity (e.g. RpoN sigma factor), as well as to antimicrobial agents (e.g. tetracyclines, quinolones, and macrolides). In the food production chain, Campylobacter is thought to be particularly susceptible to oxidative and desiccation stresses; however, C. jejuni has been demonstrated to be able to adapt to aerobic atmosphere by activating a range of enzymes, including KatA catalase. Thermophilic campylobacters are also able to respond to low temperatures encountered in food processing, even though the growth is particularly slow down. One of the food sources allowing a long-term survival of C. jejuni is the "chicken juice", in which it is able to form biofilm after expression of the quorum sensing system activated by the luxS gene. Under stressful conditions,

Prediction of edapho-climatic parameters in the incidence of Campylobacter spp. in northwestern Mexico

“…Furthermore, the soil has been demonstrated to significantly contribute to the persistence of the bacterium in the environment. This is attributed to its relative significance as a potential infection source, linked to the bacterium’s resistance to environmental conditions [ 18 , 47 ]. With this study we intend to improve our understanding of the presence of Campylobacter spp.…”

“…If we consider that many of its reservoir groups, especially mammals, use or live in and within the soil and contribute directly to its formation, it is essential to take into account the influence of edaphic characteristics in the maintenance of Campylobacter spp . [ 18 ]. For example, rodents and carnivores that dig deep into the soil carry out a considerable mixing of the soil, often bringing subsoil to the surface and leaving a cavity into which the top soil can fall and accumulate in the subsoil [ 15 , 19 ].…”

Genomic insights into zoonotic transmission and antimicrobial resistance in Campylobacter jejuni from farm to fork: a one health perspective

“…However, recent reports have also highlighted the role of wildlife and the environment (e.g. soil and water) in disease transmission [ 6 ]. The prevalence of Campylobacter infections is a critical global health concern.…”