Due to intensive use of β-lactam drugs as therapeutic agents and
growth promoting the β-lactam resistant is developed,and it is
primarily developed by β-lactamases . therefore ,the objective of this
study was to characterize β-lactamase genes in E. coli isolated from
broilers. A total of 105 sampels isolated from broilers from Gharbia
governorates ,28 isolates were positive for E.coli (26.6%), 15 isolatas
were randomly taken and they serogrouped to 7 serotypes (O 55,
O78, O 125, O126, O 157, O119 :H6 ,and O1:H7) .All isolated strains
showed multidrug resistance phenotypes particularly against
amoxicillin, erythromycin, doxycyclin, norfloxacin, and colistin
sulphate respectively, PCR for the detection of β-lactamase genes in
isolated strains showed that , all isolates contain β-lactamase genes,
5 isolates contain bla TEM 5 (50%), 2 isolates contain bla CTX-M 2
(20%), 3 isolates contain bla OXA 3 (30%), 2 isolates contain bla
SHV 2 (20%), 1 isolates contain both bla TEM and bla OXA, 2 isolate
contain both bla TEM and bla CTX-M and 1 isolate contain three
gens bla TEM , bla SHV, and bla CTX-M .