Abstract:
Pathogenic Escherichia coli of breeder hens in most of the cases involve to use antibiotic therapy, but for better results it is important
to identify the bacterial susceptibility to antibiotics in order to avoid the selection of resistance strains. Also it causes important
economic losses by morbidity wich lead to decreasing egg production, decreased growth rates ,additional costs for treatment and
prophylactic measures. The colibacilosis disease may occur by poor environmental conditions wich lead to decline of immunity status
of hens. The obtained results showed that a high proportion (78% and 55%) of E. coli-positive samples were resistant to Ofloxacin
and Gentamicin what can be concerned for poultry farmers from Republic of Moldova, due to often uses of this antibiotics in rearing
proces of poultry, but high frequency of resistant isolates against Doxycycline Hydrochloride (88%) might be explained by high rates
of use as prophylactic measures in breeder flock and poultry rearing. It should also be mentioned that the hight rates of antimicrobial
resistance in hens suggests the possibility of vertical transmission from hatcheries, through the eggs to the next generations of poultry.