Genetically Engineered Microorganisms and Their Impact on Human Health

Table 1

Studies on therapeutic effects of genetically modified phages.

Engineered phage	Method of making engineering phage/route of ad	Target	Mode of action of engineered phage	Outcome	Ref
M13mp18	Insert genes in pZE11G vector and cloned in phage/IP	E. coli K-12	Express lexA3, soxR, csrA, and ompF genes on phage	Enhance penetration and bactericidal activity of antibiotic	[70]
T7	Integration genes in phage by homologous recombination in E. coli host strain	E. coli DH5a	Expression lnqQ and trxA on T7 phage	Production of bacteriocin; Increased T7 phage lytic activity which leads to prevent the emergence of resistant bacteria	[71]
M13	Phagemid constructed by cloning by plug-and-play cloning platform/IP	E. coli	Expressing antimicrobial peptides (cecropin, apidaecin) and protein toxin (ccdB) on phagemid	Interfere with bacterial intracellular processes such as septum formation, DNA replication, DnaK activity, and protein production	[72]
phi11	Cloning and allelic exchange techniques	S. aureus	Expression of SASP gene of B. megaterium on phage	Inactivation of DNA, enhancement of bactericidal activity, effective against all the S. aureus; Low propensity for resistance development	[73]
M13	Phagemid constructed by cloning	E. coli O157: H7	Engineered a modified nonreplicating M13-derived phage expressing a lethal catabolite gene CAP	Killing of adenyl cyclase positive bacteria by lethal cap protein transfer	[74]
λ	Plasmid vector, inherent red recombination system/oral	E. coli MG1655	Phage that targets SXT2 toxin expression	In vitro lysogenize and suppress Stx2 synthesis in E. coli; Drastic reduction of Stx2 production in vivo	[75]
NM1	Phagemid constructed by cloning by tracrRNA and CRISPR array/topically	S. aureus	Plasmid targets the aph-3-kanamycin resistance gene	Inactivation of target bacterial functions and immunization of nonvirulent strains against plasmid-borne horizontal transfer	[76]
M13	CRISPRCas13a/administration of phage into larvae	E. coli and S. aureus	Construct targeting antibiotic resistance genes (bla, mcr, mecA)	Killing activity against bacteria carrying the blaIMP-1 gene	[76]
T7	Insertion a construct into the phage genome with a T7Select 415-1 kit	E. coli BL21	Expressing of fluorescent marker mCherry and antimicrobial peptide	Eliminating both biofilms and planktonic cells	[77]
M13	λ-red recombineering using pSIM9 system	E. coli EMG2	Engineered a phage harboring RNA-guided nuclease that targets blaSHV-18 or blaNDM-1 and gyrA genes to break DNA in antibiotic resistance genes	Decrease in viable cells and DNA damage in target cells	[78]
M13	Phagemid constructed by cloning	E. coli	Expression of λS105 holin in phage M13S105 and BglII restriction endonuclease in M13R phage	Decrease by more than 99% in bacterial viability	[79]
M13	Phagemid constructed by cloning/IP	E. coli	Expression of lethal agents Gef and ChpBK	Decreased target bacterial populations	[80]
T7	Cloning extracellular matrix polymer gene of A. actinomycetemcomitans in phage	E. coli TG1	Express DspB (dispersin B) intracellularly during infection	Efficient deletion of biofilm-producing bacteria	[81]
λ	CRISPR-Cas9	E. coli	Phage targets ndm-1 and ctx-M-15 genes (β lactamases encoding genes)	Loss of resistance determinants, minimization of horizontal transmission, instead of killing resistant bacteria, it sensitizes them and then enriches this sensitive population	[82]
φSaBov	CRISPR/Cas9/SC	S. aureus	Deliver a CRISPR/Cas 9 carrying phage that targets nuc gene	Improve efficiency of S. aureusspecific-killing by SaBov-Cas9-nuc to full eradication, and CFU reduction	[83]
M13 phage/S. aureus phage 80α	CRISPR-Cas13a/Administration of phage into larvae	E. coli NEB5- and S. aureus USA300	Phage that carries CRISPR system targets carbapenem-resistant genes (blaIMP-1, blaOXA-48, blaVIM-2, blaNDM-1, and blaKPC-2) and colistin-resistant genes (mcr-1 and mcr-2) in E. coli/CRISPRCas13a system in phage targets S. aureus rpsE genes and the methicillin-resistant gene mecA	Specific killing of carbapenem and colistin-resistant E. coli and MRSA	[76]
M13	CRISPR-Cas9 phagemid vectors/oral	Streptomycin-resistant E. coli	M13, which carries CRISPR-Cas9, targets E. coli that has sfGFP (green fluorescence) marker gene	Strain-specific reduction of fluorescently marked isogenic strains during competitive colonization	[84]

SASP, small acid soluble spore protein; CAP, catabolite gene activator protein; tracrRNA, trans-activating crRNA; SC, subcutaneous injection; MRSA, methicillin-resistant Staphylococcus aureus; A.a, Aggregatibacter actinomycetemcomitans.