TABLE 1.

Sample sources, susceptibility to antibiotics, and mechanisms of potential AMR gene transfer to the environment.

Sample sources	Susceptibility to antibiotics	Mechanisms of AMR gene transfer	References
Poultry fecal waste	The study indicated that poultry samples showed a high prevalence of CTX-M cluster 9 and blaTEM.	Horizontal transfer of ARGs by Bacteriophages	Colomer-Lluch et al., 2011
Composted poultry manure	Poultry manure applications increased AMR genes in the rhizosphere, root endophyte, and phyllosphere, suggesting poultry manure may have an impact on lettuce resistomes.	No mechanism reported.	Zhang et al., 2019
Poultry litter	50% of these isolates were susceptible to ampicillin, 57% to erythromycin, 25% to tetracycline, 4% to chloramphenicol, 40% to kanamycin, 75% to streptomycin, 54% to tobramycin, and 4% to rifampicin.	Transformation and conjugation was reported as a mechanism for horizontal gene transfer between bacteria in poultry litter.	Sridevi Dhanarani et al., 2009
Poultry litter and soil	Out of the 13 antibiotics tested for E. coli, high (>70%) and similar (in the range of 10–15%) resistance against 7 antibiotics was observed in samples from both litter and agricultural soils where poultry litter applied.	No mechanism reported.	Bhushan et al., 2017
Poultry litter	The 86% of litter isolates (163 isolates in total) were resistant to more than one antibiotic.	No mechanism reported.	Furtula et al., 2013