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Live MG vaccines are an effective controlmeasure in commercial layers, but escape ofthe vaccine strain to neighboring poultry flocksis a concern. DNA fingerprinting has enabledus to readily identify such occurrences.Identification of one live MG vaccine strain inbroiler breeders was investigated. Neighboringcommercial layers were most likelyinadvertently infected by using a vaccine bagthat had contained MG vaccine the previousday. The organism then spread within the flockand to the neighboring broiler breeders. Thisand other recent examples emphasize the needfor proper use of live mycoplasma vaccines.Clinical infectious synovitis (caused byMS) was noted in Minnesota turkey flocks thatwere negative by standard serological tests. Anisolate from this flock was used to challengeexperimental turkeys. Turkeys infected via theupper respiratory infection were culturepositive but remained negative on allserological tests. This emphasizes the need forfurther investigations in situations in whichclinical signs are seen but antibody tests arenegative.These results improve our ability to detectand control MG and other mycoplasmas incommercial poultry.Stanley H. Kleven, Willie D. Hall, VictoriaLeiting, Tongrui Liu, and Maricarmen Garcíaskleven@arches.uga.eduA second neuraminidase gene cloned fromPasteurella multocida“Sometimes there breaks out in thepoultry-yard a disastrous disease, commonlyknown as chicken cholera. The animal whichis prey to this infection is without strength,trembles and has drooping wings.” Thesewords were spoken by Louis Pasteur in 1880when he revealed his fowl cholera vaccine tothe Paris Academy of Sciences. Pasteur, nowknown as the father of modern microbiology,developed the first attenuated-live vaccineeffective against infection. Live vaccinestrains are still used today to prevent fowlcholera; however, the available live vaccinestrains are often too pathogenic for use inchickens, and killed vaccines induce protectionagainst only closely related strains ofPasteurella multocida, the bacteriumresponsible for the disease. We propose tocreate a recombinant vaccine that will induceprotection against all P. multocida strains. Wehave cloned and sequenced a neuraminidasegene present in all strains of P. multocida andhave protected chickens from fowl cholerausing recombinant protein from this gene. Weare the first to discover that P. multocidacontains multiple neuraminidase genes. Theobjectives of this study are to 1) determine theDNA sequence of nanB the second neuraminidasegene cloned from P. multocida,2) determine the substrate specificity of thetwo neuraminidases, 3) create isogenic mutantsdeficient in production of the two activeenzymes, and 4) complement mutants withcloned copies of specific neuraminidase genes.Margie D. Leeleem@calc.vet.uga.eduRapid identification and epidemiologicaltyping of food-borne pathogens by PCRMany foods including poultry productshave a short shelf life in the supermarket.Microbial testing will require sensitive andrapid methods for detection of biologicalhazards and typing of these food-bornepathogens. Molecular biology has provided thekey tools for rapid identification of pathogens.The objectives of this study are to 1) develop arapid method for identifying food-bornepathogens Campylobacter, Escherichia coliO157:H7, and Salmonella using multiplexpolymerase chain reaction (PCR) and enzymelinkedimmunoadsorbent assay (ELISA); and2) type Salmonella and Campylobacter bymultiplex, restriction fragment lengthpolymorphism (RFLP) and randomamplification polymorphic DNA (RAPD)PCR. Several PCR-basedmethods were developed toreplace currentimmunological methods toidentify importantSalmonella and E. coliserotypes. The primers weredesigned to target andamplify the O and flagellarantigen genes. PCR testswere developed for rapiddetection of E. coli O157serotypes and Salmonellaserovars, B, D1, and C1.ELISA modified the currentE. coli O157 PCR testtowards a cost-effectivedetection method forscreening a multitude ofsamples. A RFLP PCR forflagellin genes providedfurther serological typing ofSalmonella by matchingRFLP patterns against adatabase of knownSalmonella flagellin geneRFLP patterns. Onceidentified down to the Oand flagellin serotype,Salmonella can beThe laboratory of Dr. Mark Jackwood usesmolecular biological methods to develop vaccinesand diagnostic tests for important avian diseases.9
differentiated further at the genetic level bymolecular techniques involving pulsed-fieldgel electrophoresis or random polymorphicDNA PCR. Salmonella enteritidis, however,remains resistant to discrimination by thesetyping methods. Several Salmonella virulencegenes have been identified as potentialcandidates for molecular typing by RFLP PCRor DNA sequencing of S. enteritidis and otherSalmonella.John J. Maurerjmaurer@arches.uga.eduAdaptive response(s) of avian tendon toinjurySpontaneous tendon failure in heavy meattypebirds is poorly understood. This proposalwill correlate the effects of altered load on thein vitro and in vivo expression of matrixproteins; fibrillar procollagen I and collagenIII; proteoglycans, aggrecan, and decorin; andexpression of regulatory proteins TGF β , CTGF,and Hsp47. Specific aims are, first, todetermine the roles of TGF β and Hsp47 andtheir interaction in expression of embryonicand posthatch fibrillar collagens. Second, todefine biomechanical parameters of gastrocnemiustendons undergoing stress-relatedstructural changes. Third, to determinestructural changes in collagen(s) and proteoglycansin gastrocnemius tendons subjected toaltered load. In tendon explant culturessubjected to surgical trauma, there was anacute upregulation of TGF β mRNA followed bysustained upregulation of CTGF mRNA inanother 48 hours with concurrent downregulation of TGF β mRNA. Hsp47 mRNAexhibits no difference to either injury or heat inexplant cultures. Biomechanically, exerciseproduces a response related to the parameter ofstiffness compared with controls suggestingaccelerated maturation of the tendons. Pilotwork in environmental chambers indicatedthat, first, we need to cycle a high temperaturefor seven to eight hours minimum. Andsecond, we want the density of birds atapproximately 1 square foot per bird. Thefinding of a ruptured tendon in the group fedan occiodiostat, 3-nitro, was interesting.G. N. Rowland, Jaroslava T. Halper, andTimothy L. Foutz*growland@arches.uga.edu*Biological Agricultural EngineeringInvestigation into factors affectinghatchability and chick qualityCommonly used disinfectants can have anadverse effect on hatchability and chick qualityif used in high doses. Increasing the activity ofthese disinfectants would allow the use of alower concentration and result in fewerpotentially toxic effects on the hatching eggand resulting chick while maintaining a lowlevel of bacteria in the air within theincubators. This study evaluated theeffectiveness of a quaternary ammoniumcompound (Biosentry 904) misted into an eggincubator according to commercial guidelinesagainst an Escherichia coli bacteria known tobe pathogenic to chickens. This product wasalso misted into another incubator at onefourththe commercial concentration but wascombined with EDTA-Tris in a ratio shown toincrease the activity of the disinfectant againstthis particular bacteria in the laboratory. Whenthe commercially blended disinfectant wascompared with distilled water or thedisinfectant/EDTA-Tris compound, nosignificant difference was found in egg shellpermeability and egg weight or moisture lossduring the incubation period. Aerosol bacterialcounts measured inside the incubator duringincubation were actually increased with theaddition of EDTA-Tris to the disinfectant whencompared with bacterial counts measured inthe incubators misted with straight disinfectantor even distilled water. Fertility andhatchability of the eggs exposed to the varioustreatments were not affected. Early embryonicmortality was significantly higher in the eggsmisted with distilled water when comparedwith eggs exposed to either disinfectantmixture. One-day-of-age chick weights werenot significantly different, although malechicks were slightly heavier than femalechicks.Jean E. Sander, Jeanna L. Wilson, andJohn J. Maurerjsander@arches.uga.eduInvestigation of natural disease outbreaksThis project is an ongoing proposal thatprovides diagnostic laboratory support for thepoultry industry, source material for research,and teaching experiences for students in theMaster of Avian Medicine and other graduateprograms.The new lab database was placed on-lineJanuary 4, 1999 and has already providedsignificant improvements in administration andaccounting for the diagnostic lab. Moreimprovements are scheduled for this year. Labreports can now be provided by e-mail and faxdirectly from within the system without theneed for an intermediate hard copy.The polymerase chain reaction (PCR)technique has become a more integral part ofthe diagnostic laboratory as seen by the tripling10
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Page 27 and 28: Lukert, P.D. Bovine enteric disease
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