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6.6 Challenges Ahead
The application of CRISPR network as gene editing tool has engrossed the scientific
community due to its potential applications. With the advent of this tool, overcoming antimicrobial resistance using CRSIPR has opened up new vistas albeit with its
share of challenges.
6.6.1 Intricate Diversity of Bacterial Population
Despite the colossal future prospects of CRISPR network, currently Cas9 system
for management of antimicrobial resistance is generally studied on small bacterial
population. But in real time, bacteria are omnipresent and are quite diverse. This
diversity of microbial community can be an obstacle to use Cas9 system for antimicrobial resistance management. For instance, even one gram of matrix containing
cells in millions has more than thousand species. Variety of plasmids and genetic
elements possessing different genes causing antimicrobial resistance can be found
in single lineage. Unpredictability of extensive range response towards the stress by
microbial community is the second challenge. Removal of certain plasmid or elimination of a particular strain may result in outgrowth of more pathogenic species.
The repercussions of eliminating antimicrobial resistance causing gene by CRISPRCas9 system till date are still being assessed and needs more substantial positive
outcomes to make it a preferred technique to overcome antimicrobial resistance
(Pursey et al. 2018; Thomas and Nielsen 2005; Spencer et al. 2016; Marbouty et al.
2017; Theriot et al. 2014; Jorth et al. 2014).
6.6.2 CRISPR-Cas Delivery Mechanism
Owing to a large size of CRISPR-Cas9 complex (160KDa), transfer of this assembly into the cell is a challenge. There are many ways used to deliver this machinery
into the target cell. Bacteriophages, nanocages and nanosized Cas9 assemblies are
some methods for the same. A report in 2014 suggested the use of capsids to deliver
the CRISPR-Cas9 nuclease complex into the bacteria (Citorik et al. 2014). In order
to fit in the capsid, special plasmids are designed. These plasmids are called phagemids. Transduction of these plasmids to facilitate the transport of Cas9 system efficiently degrades the antimicrobial resistance bacteria (Citorik et al. 2014; Euler
et al. 2014). Since most of the antimicrobial resistance genes are located on the
plasmids, their spread via horizontal gene transfer among the bacteria that populates
a common niche is not an event of rare occurrence and thus these antimicrobial
resistance causing genes disperse in wide range of bacterial species. The specificity
6 Role of Gene Editing Tool CRISPR-Cas in the Management of Antimicrobial…
6.6 Challenges Ahead
The application of CRISPR network as gene editing tool has engrossed the scientific
community due to its potential applications. With the advent of this tool, overcoming antimicrobial resistance using CRSIPR has opened up new vistas albeit with its
share of challenges.
6.6.1 Intricate Diversity of Bacterial Population
Despite the colossal future prospects of CRISPR network, currently Cas9 system
for management of antimicrobial resistance is generally studied on small bacterial
population. But in real time, bacteria are omnipresent and are quite diverse. This
diversity of microbial community can be an obstacle to use Cas9 system for antimicrobial resistance management. For instance, even one gram of matrix containing
cells in millions has more than thousand species. Variety of plasmids and genetic
elements possessing different genes causing antimicrobial resistance can be found
in single lineage. Unpredictability of extensive range response towards the stress by
microbial community is the second challenge. Removal of certain plasmid or elimination of a particular strain may result in outgrowth of more pathogenic species.
The repercussions of eliminating antimicrobial resistance causing gene by CRISPRCas9 system till date are still being assessed and needs more substantial positive
outcomes to make it a preferred technique to overcome antimicrobial resistance
(Pursey et al. 2018; Thomas and Nielsen 2005; Spencer et al. 2016; Marbouty et al.
2017; Theriot et al. 2014; Jorth et al. 2014).
6.6.2 CRISPR-Cas Delivery Mechanism
Owing to a large size of CRISPR-Cas9 complex (160KDa), transfer of this assembly into the cell is a challenge. There are many ways used to deliver this machinery
into the target cell. Bacteriophages, nanocages and nanosized Cas9 assemblies are
some methods for the same. A report in 2014 suggested the use of capsids to deliver
the CRISPR-Cas9 nuclease complex into the bacteria (Citorik et al. 2014). In order
to fit in the capsid, special plasmids are designed. These plasmids are called phagemids. Transduction of these plasmids to facilitate the transport of Cas9 system efficiently degrades the antimicrobial resistance bacteria (Citorik et al. 2014; Euler
et al. 2014). Since most of the antimicrobial resistance genes are located on the
plasmids, their spread via horizontal gene transfer among the bacteria that populates
a common niche is not an event of rare occurrence and thus these antimicrobial
resistance causing genes disperse in wide range of bacterial species. The specificity
6 Role of Gene Editing Tool CRISPR-Cas in the Management of Antimicrobial…