Plasmid analysis in relation to antibiotic profile in pathogenic escherichia coli

Bovine calf scours or neonatal diarrhea of calves is a severe form of diarrhea that causes more financial loss to cow-calf producers than any other disease-related problem .Strains that cause enteric infections are designated diarrheagenic E.coli, a group that includes emergent pathogens with public health relevance worldwide . Six categories of Escherichia coli have been well associated with diarrhoea in several epidemiologenteropathogenic E. coli (EPEC), enteroaggregative E.coli (EAEC), enterotoxigenic E.coli (ETEC), enteroinvasive E. coli (EIEC), Shiga toxin-producing E. coli (STEC),and diffusely adherent E.coli (DAEC).The virulence mechanisms that characterize these categories of E. coli are genetically encoded by chromosomal, plasmid, and bacteriophage DNAs.Identification of diarrheagenic E. coli strains requires that these organisms be differentiated from nonpathogenic members of the normal flora. Serogrouping of O antigen is not sufficient to identify a strain as diarrheagenic, because it does not correlatBacterial resistance to antimicrobial agents is a major world wide problem because it is transferable in nature and often the multiple drug resistance isolates of E.coli or other bacteria are invariably associated with various diseases.The drug resistance may be chromosomal DNA or plasmid DNA mediated. Plasmids are autonomously replicated DNA which are extra chromosomally located in the micro-organisms. The plasmid mediated drug resistance is caused due to the presence of drug resistantThis study aimed to :1) : isolation of 28 strains from diarrheagenic calves and 5 strains from human and were identified it is E.coli by biochemical tests as : lactose fermentation , indol and methyl red production tests .2): Antibiotic sensitivity test was applied on 14 isolates from diarrheagenic calves and 5 isolates from human by using 14 types of differnt antibiotic .3) : Detection of some virulence factors genes ( intimin , F41 and Stx2) from highly 3resistant and lower 3 resistant isolates by using single PCR .The result of this study was :*Antibiotic sensitivity test :It was found that , Amikacin and Sulphamethoxazole /Trimethoprim were the most effective antibiotics on calf and human isolates ;while Cephalexin , Cefoxitin , Amoxycillin / Clavulanic acid and Ampicillin / Sulbactam did not show any sensitivity percent .*PCR results :-Calves isolates :Two isolates of highly resistant strains and one of low resistant strain were positive to ( intimin) . only one of low resistant strain was positive to ( F41) ; no of strains shew positive to Stx2 .-Human isolates :No strain shew posiivity to intimin gene . only one isolates of low resistance was positive to F41 . oe isolate of highly resistant isolate was positive to Stx2 .These results came in agreement with many studies similar to it which indicate high antibiotic resistance . Also, presence of virulence factors that help colonization of the organism and induce the severity of the disease . So, there is acorrelation betwe