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Current Trends in Biotechnology and PharmacyVol. 5 (2) 1123-1129 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1127in 2,360 out of 20,878 sheep sera examined(11.7%), and in 85 out of 1,162 examined goats(7.7%) in slovek republic (2).The lack of detection of chlamdyial antigenby MZN or by culture is consistent with thatreported by Clarkson and Philips, (3), who couldnot detect C. abortus in the faecal samplesobtained from ewes in farms where enzooticabortion was endemic. However, other workershave reported that C. abortus is occasionallyisolated from faeces (16). It appears that C.abortus is not excreted in the faeces of naturallyaborting ewes but further studies are needed toexamine flocks where enzootic abortion is presentand for the possible role of faeces as source ofinfection, as some enteric isolates were reportedto be capable of causing abortion in pregnant ewesafter intravenous injection (15).In the present study attempts to demonstratechlamydial antigens by immunohistochemicalstaining of sections of the reproductive tractobtained from ewes six months after chlamydialabortionwere also unsuccessful. This is also incontradiction to the observations of Papp et al(11), who reported the demonstration ofchlamydial antigens in vaginal and cervicalsamples obtained from chronically infected ewesusing immunohistochemistry. However, theirsamples were obtained from ewes that hadexperienced C. abortus induced abortion 3 yearsearlier. Whereas in the present study the sampleswere obtained during the second oestrus cycle,six months after abortion due to C. abortus.The Clearview Chlamydia test kit is reportedto provide fast and easy-to-use method for thedetection of chlamydiae. It has high sensitivity,which makes it a useful screening tool, but it isnot species-specific as the LPS it detects areshared by other chlamydiae and possibly otherbacteria.It has been reported that C.abortus persistsin subepithelial cells in the vagina, uterus, andoviduct of chronically infected ewes. Invasion ofthe chlamydiae beyond the mucosal epithelial cellsprovide opportunity for persistence. So it possiblethat viable C. abortus had not been excretedsecretion during the period of collection.The Polymerase Chain Reaction (PCR),which is easy, sensitive and quick method ofdetection, is now widely used for the detection ofC abortus. One advantage of using PCR forthe detection of EAE is that viable EB do nothave to be present, unlike the requirements forcell culture isolation. A PCR was used to detectthe genome of Chlamydophila abortus insamples of uterine tissue collected from 304sheep. The total prevalence of the chlamydialgenome was 30.9 per cent, with a significantlyhigher prevalence in the pregnant animals as 46.9per cent. (10)In the present study PCR was used as aconfirmatory tool after extracting DNA fromfaeces and vaginal secretions‘ using primersspecific to the MOMP gene as described byCreelan and McCullaugh (4). The use of ovineabortificient strain-specific primers for thedetection of DNA from placental tissues wasreported to be a sensitive and specific. Thespecificity of clone 8 primers for C. abortusavoids the potential detection of C. pecorum,which is known to infect sheep (6). None of thesamples tested were positive, suggesting thateither there were no EBs ofC. abortus in thesamples or there were non infectious forms (RBs)which could not be detected by DNAamplification. It has been reported thatchlamydiae can be detected at early stage byribosomal RNA (rRNA).A variety of sample preparation methodssuch as immunomagnetic separation (IMS) havesuccessfully been applied to improve theStudies on carrier state of Chlamydophila abortus
Current Trends in Biotechnology and PharmacyVol. 5 (2) 1123-1129 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1128sensitivity of PCR assays (5). Real-time PCRanalysis of placental samples identified very fewor no chlamydial genomes, which contrastedsignificantly with samples taken at the time ofabortion. The results suggested that the low levelsof chlamydial DNA detected during theperiovulation period and at lambing do notsignificantly impact on the epidemiology of EAE.In terms of flock management, the products ofabortion should be considered the major andprincipal source of infection for transmission tonaïve ewes. (8)The C. abortus was detected by PCR forthe first time in milk samples collected from eweswith EAE history using the IMS technique.However, the absence of a C. abortus using PCRand IMS in some animals with EAE history doesnot necessarily mean that they were free fromthe disease, as the possibility of excretion in milkis considered to be rather low (17). Chlamydiaemay be present in low numbers in ewes and shedonly intermittently or that other animals could actas reservoirs of infection (3). It is possible thatthe organism did not persist in the aborting ewesor the concentration of C. abortus DNA in thereproductive tract of persistently infected ewesso low, that it cannot be detected by PCR.The peri-glandular region of basal zone ofendometrium is an area where infiltratingmacrophages reside (7). Infiltration ofmacrophages in peri glandular cells may helppresentation of chlamydial antigen to be presentedto MHC Class II and to stimulate the productionof systemic antibodies. The serum samples fromthese ewes showed significantly higherchlamydia-specific IgG titre during the period ofperi-ovulation. This finding is in close agreementwith that of Papp et al. (11). There was also anincrease in antibody reactivity during theperiovulation period in 3 of the 8 sheep examined,with a slight increase in IgM and IgG antibodies.Specific antichlamydial antibodies can neutralizechlamydial infectivity in vitro by preventingattachment to target cells or facilitatingintracellular destruction. In terms of flockmanagement, as suggested earlier by manyresearchers (8), the products of abortion shouldbe considered the major and principal source ofinfection for transmission to naïve ewesReferences1. Bagdonas, J, Petkevicius, S, Russo, P, Pepin,M. and Salomskas, A. (2007). Prevalenceand epidemiological features of ovineenzootic abortion in Lithuania. Pol J Vet Sci.,10(4); 239-244.2. Cisláková, L., Halánová, M., Kovácová, Dand Stefancíková., A. (2007). Occurrenceof antibodies against Chlamydophila abortusin sheep and goats in the Slovak Republic.Ann Agric Environ Med.,14(2); 243-5.3. Clarkson, M. J. and. Philips., H. (1997).Isolation of faecal Chlamydia from sheepin Britain and their characterisation bycultural properties. Veterinary Journal. 153;307-310.4. Creelan, J. L. and Samuel J. McCullough.(2000). Evaluation of strain- specific primersequences from an abortifacient strain ofovine Chalmydophila abortus (Chlamydiapsittaci) for the detection of EAE by PCR.Infection and Immunity. 1; 103-108.5. Djonne, B., Jensen, M. R., Grant, I. R andHolstad, G (2003). Detection byimmunomagnetic PCR of Mycobacteriumavium subsp. paratuberculosis in milk fromdairy goats in Norway. VeterinaryMicrobiology 92; 135-143.6. Fukushi, H and Hirai, K. (1993). Restrictionfragment length polymorphisms of rRNA asRabia Abadía Elzlitne et al
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(December 7-9, 2011)Venue: Karunya
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