Food poisoning outbreaks resulting from Salmonella growing in vegetables have demonstrated the need for knowledge of pathogen evolution and adaptation in developing appropriate countermeasures for prevention and policy development.
Such genes can be regarded as S genes, and can function for instance in facilitating host recognition and penetration, negative regulation of host defences or fulfilling metabolic and structural needs of the pathogen [ 12].
From the haustorial mother cell, a narrow haustorial neck penetrates the wall of the mesophyll cell and develops into a haustorium, which establishes an obligate biotrophic relationship with the living plant cell by redirecting the host's metabolism to meet nutritional needs of the pathogen without causing immediate death of host cells [ 15, 16].
Several lectins with early (1 dpi) induction in skin have unknown roles but may be needed for detection of pathogen; the calcium dependent (C-type) lectin domain family 4 E is expressed in macrophages and other Ag presenting cells [ 15].
Importantly, taken together, our results suggest the interconnected and tradeoff relationship between antibiotic resistance determinant, virulence regulators, and metabolism, and thus the need for systems analysis of pathogen physiology and responses to therapeutic interventions.
These secreted proteins may disable plant defences and subvert cellular processes to suit the needs of invading pathogens.
The above stated systems can directly detect target DNA and can circumvent the need for culturing of pathogens and amplification of target DNA in the specimens.
Recent examples of pathogens emerging in new areas of the globe, driven by changes in wildlife host migration patterns, illustrate that environmental drivers of pathogen spread need to be included in the holistic development of disease mitigation interventions (Altizer et al. 2013 ; Goldstein et al. 2009 ).
However, alternative methods of disease control are needed because of the emergence of pathogen strains resistant to the chemicals such as mefenoxam and metalaxyl (Parra and Ristaino,2001) and the high concern about the adverse effects of pesticides on human health and the environment (World Health Organization,1990).
To optimize the scenarios that predict the risks associated with the emergence and spread of disease, epidemiologists need to understand the complete process of pathogen dissemination and survival.
