Sialic acids from the human host are used by a number of pathogens as an energy source.
In this regard, the widespread emergency practice of applying preventive antibiotics even in the apparent absence of known pathogens, though criticized as a source of selection for antibiotic resistance, might not be such a bad idea [ 40].
Yet, intentionally providing a pathogen with a source of permissive cells seems counterintuitive as a defense strategy.
The IMI in heifers with host adapted pathogens can also act as a source of new IMI for lactating dairy cows.
Results with amino acids-deprived tissue culture cells and a L. monocytogenes mutant auxotrophic for threonine indicate that this pathogen may utilize intracellular peptides as a source of amino acids [ 7].
Several wild Vitis species have instead been found to be resistant to this pathogen and have been used as a source to introgress resistance into a V. vinifera background.
Citrus production worldwide is threatened by the disease Huanglongbing (HLB), caused by the phloem-limited pathogen Candidatus Liberibacter spp. As a source of stable HLB-resistance has yet to be identified, there is considerable interest in characterization of novel disease-associated citrus genes.
Most vaccines are designed empirically using attenuated pathogens as the source of foreign antigens (Ag).
In critical illness, the intestine has been indicted as a source of pathogens sustaining the inflammatory response initiating or maintaining multiple organ failure.
Studies have demonstrated that transporters need to be thoroughly cleaned to prevent them from acting as a source of pathogens to subsequently carried animals, for example to prevent transmission of porcine reproductive and respiratory syndrome virus, that can survive in transporters, being transferred to pigs [ 37].
Isolates of Nocardia cyriacigeorgica have recently been reported in a variety of clinical scenarios [ 18- 20] making this organism an important clinical pathogen, which is increasingly being reported as a source of infection in the United States [ 17].
