Detection of Colicin genes by PCR in Escherichia coli isolated from cattle in Shiraz-Iran Tahamtan 1

ABSTRACT A variety of probiotic bacteria have been tested to control animal and foodborne pathogenic bacteria in livestock. The mechanism of inhibition of pathogenic bacteria for several of those probiotic microorganisms is mediated by the production of bacteriocins. Colicins are probably the group of bacteriocins that have been most thoroughly characterized. Colicins are antimicrobial proteins produced by one strains of Escherichia coli to suppress the growth of other strains of E.coli. The present study indicated the preparation of colicin from colicinogenic bacteria. A total of three hundred rectal and rumen swabs isolated from health and diarrheic calves located in Fars province feces. One hundred and fifteen strains were confirmed as E.coli by biochemical test. Polymerase chain reaction was used to determine the following genes encoding colicins. Nearly 100% of isolates were contained at least one gene of colicin. The frequency of several classes of colicin was determined. As a result the most detected gene was Ia Ib and the least detected gene was A.N.S 4 . Colicin should be tested to control animal and foodborne pathogenic bacteria in livestock

Prevalence and molecular characterization of verotoxin-producing Escherichia coli O157:H7 in cattle and sheep in Shiraz-Iran

Shiga toxin producing Escherichia coli have been associated with HUS, HC and TTP in human. We found recto-anal mucosal sample in sheep as well in cattle is the main site for E. coli O157 localization. 1246 E. coli isolates from 872 both healthy and diarrheic animals were analyzed, by screening for the presence of Shiga toxin-producing (VT 1 and VT 2) and intimin (eae) genes used Multiplex PCR. 87(9.75%) VTEC from 52 cattle and 28(7.90%) from 28 sheep were isolated. VT2 gene was found to be more frequent than VT1 in cattle (54.02% vs 26.43%), in contrast the same genes in sheep (21.42%vs25%). There was observed significant difference in the origin of VT positive sheep in close contact with farms of cattle origin. Having cattle and sheep with each other was a possible risk factor. The animal was kept in pen was more localized than tethered. Young cattle were documented strongly significant high prevalence rate in E. coli O157:H7 than older, but no effect of age was observed on the occurrence of E. coli O157 in sheep. Both diarrheic and healthy animals were shed E. coli O157:H7 in their feces. Sheep and dairy cow were not illustrated any significance differences geographical region and seasonal variation with E. coli O157:H7 prevalence rate

Neuraminidase gene sequence analysis of avian influenza H9N2 viruses isolated from Iran (19982001) Arch. Razi Institute

ABSTRACT Influenza A viruses possesses two virion surface glycoproteins including haemagglutinin (HA) and neuraminidase (NA). The NA plays an important role in viral replication and promotes virus release from infected cells and facilitates virus spread throughout the body. To find out any genomic changes that might be occurred on NA gene of avian influenza circulating viruses, we have genetically analyzed the neuraminidase gene of six Avian Influenza (AI) viruses H9N2 subtype isolated from different parts of Iran. A comparison of deduced amino acid sequences, showed some amino acid substitutions among the local AI isolates. However no insertions/deletions or shortening in the stalk region of the genes were observed. Mutation in Glu 119 as a marker for enzyme sensitivity to the antiviral drugs was not observed. Phylogenitic analysis revealed three distinct groups among the isolates of Iran, Hong Kong, and Pakistan/Japan/Saudi Arabia respectively. Based on the results, no significant mutations in NA genes of the viruses isolated during the period of the study occurred and our findings are in agreement with results of previous study of the viruses indicated a low pathogen character for the isolates on the basis of amino acid sequence of HA cleavage site and experimental infection

Detection of Colicin genes by PCR in Escherichia coli isolated from cattle in Shiraz-Iran

A variety of probiotic bacteria have been tested to control animal and foodborne pathogenic bacteria in livestock. The mechanism of inhibition of pathogenic bacteria for several of those probiotic microorganisms is mediated by the production of bacteriocins. Colicins are probably the group of bacteriocins that have been most thoroughly characterized. Colicins are antimicrobial proteins produced by one strains of Escherichia coli to suppress the growth of other strains of E.coli. The present study indicated the preparation of colicin from colicinogenic bacteria. A total of three hundred rectal and rumen swabs isolated from health and diarrheic calves located in Fars province feces. One hundred and fifteen strains were confirmed as E.coli by biochemical test. Polymerase chain reaction was used to determine the following genes encoding colicins. Nearly 100% of isolates were contained at least one gene of colicin. The frequency of several classes of colicin was determined. As a result the most detected gene was Ia Ib and the least detected gene was A.N.S4. Colicin should be tested to control animal and foodborne pathogenic bacteria in livestock