SETTING: Haematology Lab, Department of Biomedical Science, University of Malaya.
PARTICIPANTS: Eight couples characterised as β-thalassaemia carriers where both partners posed the same β-globin gene mutations at CD41/42, IVS1-5 and IVS2-654, were recruited in this study.
OUTCOME MEASURES: Genotyping was performed by allele specific-PCR and the locations of SNPs were identified after sequencing alignment.
RESULTS: Genotype analysis revealed that at least one paternal SNP was present for each of the couples. Amplification on free-circulating DNA revealed that the paternal mutant allele of SNP was present in three fcDNA. Thus, the fetuses may be β-thalassaemia carriers or β-thalassaemia major. Paternal wild-type alleles of SNP were present in the remaining five fcDNA samples, thus indicating that the fetal genotypes would not be homozygous mutants.
CONCLUSIONS: This preliminary research demonstrates that paternal allele of SNP can be used as a non-invasive prenatal diagnosis approach for at-risk couples to determine the β-thalassaemia status of the fetus.
OBJECTIVE: To describe the pathological changes, identification and distribution of B. melitensis in foetuses of experimentally infected does.
METHODS: Twelve female goats of approximately 90 days pregnant were divided into 4 groups. Group 1 was exposed intra-conjunctival to 100 µL of sterile PBS while goats of Groups 2, 3 and 4 were similarly exposed to 100 µL of an inoculum containing 109 CFU/mL of live B. melitensis. Goats of these groups were killed at 15, 30 and 60 days post-inoculation, respectively. Foetal fluid and tissues were collected for bacterial identification (using direct bacterial culture, PCR and immuno-peroxidase staining) and histopathological examination.
RESULTS: Bilateral intra-conjunctival exposure of pregnant does resulted in in-utero infection of the foetuses. All full-term foetuses of group 4 were either aborted or stillborn, showing petechiations of the skin or absence of hair coat with subcutaneous oedema. The internal organs showed most severe lesions. Immune-peroxidase staining revealed antigen distribution in all organs that became most extensive in group 4. Brucella melitensis was successfully isolated from the stomach content, foetal fluid and various other organs.
CONCLUSION: Vertical transmission of caprine brucellosis was evident causing mild to moderate lesions in different organs. The samples of choice for isolation and identification of B. melitensis are stomach content as well as liver and spleen tissue.