Leah Peleg, PhD, Rachel Pesso, PhD, Boleslaw Goldman, MD, Keren Dotan, Merav Omer, Eitan Friedman, MD, PhD, Michal Berkenstadt, PhD, Haike Reznik-Wolf, PhD and Gad Barkai, MD
Background: The Bloom syndrome gene, BLM, was mapped to 15q26.1 and its product was found to encode a RecQ DNA helicase. The Fanconi anemia complementation group C gene was mapped to chromosome 9q22.3, but its product function is not sufficiently clear. Both are recessive disorders associated with an elevated predisposition to cancer due to genomic instability. A single predominant mutation of each disorder was reported in Ashkenazi Jews: 2281delATCTGAinsTAGATTC for Bloom syndrome (BLM-ASH) and IVS4+4A®T for Fanconi anemia complementation group C.
Objectives: To provide additional verification of the mutation rate of BLM and FACC in unselected Ashkenazi and non-Ashkenazi populations analyzed at the Sheba Medical Center, and to trace the origin of each mutation.
Methods: We used polymerase chain reaction to identify mutations of the relevant genomic fragments, restriction analysis and gel electrophoresis. We then applied the ProntoTM kit to verify the results in 244 samples and there was an excellent match.
Results: A heterozygote frequency of 1:111 for BLM-ASH and 1:92 for FACC was detected in more than 4,000 participants, none of whom reported a family history of the disorders. The ProntoTM kit confirmed all heterozygotes. Neither of the mutations was detected in 950 anonymous non-Ashkenazi Jews. The distribution pattern of parental origin differed significantly between the two carrier groups, as well as between each one and the general population.
Conclusions: These findings as well as the absence of the mutations in non-Ashkenazi Jews suggest that: a) the mutations originated in the Israelite population that was exiled from Palestine by the Roman Empire in 70 AD and settled in Europe (Ashkenazi), in contrast to those who remained; and b) the difference in origin distribution of the BS and FACC mutations can be explained by either a secondary migration of a subgroup with a subsequent genetic drift, or a separate geographic region of introduction for each mutation.
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Imad R. Makhoul, MD, DSc, Polo Sujov, MD, Leon Ardekian, DDS, Imad Kassis, MD, Tatiana Smolkin, MD, Imad Abu-Elnaa'j, DMD, Ada Tamir, DSc and Dov Laufer, DMD
Background: Factors influencing the oral flora of premature infants have not been adequately investigated.
Objective: To investigate the effects of gestational age and of anti-bacterial therapy on the oral flora of premature infants.
Methods: Oral cultures were obtained at age 1 day and age 10 days from 65 premature infants, divided into three groups: a) 24 neonates of 30-34 weeks gestation who did not receive ABT, b) 23 neonates of 30-34 weeks gestation who received ABT, and c) 18 neonates < 30 weeks gestation who received ABT.
Results: Oral bacterial colonization increased from day 1 to day 10 of life. In 24-34 week neonates, gestational age did not affect early bacteremia or oral colonization at birth. Neither gestational age nor ABT affected late bacteremia or oral colonization at day 10. In 30-34 week neonates with ABT, the oral flora consisted mainly of non-Escherichia coli gram-negative bacteria, whereas those who did not receive ABT grew mainly alpha-hemolytic streptococci, Klebsiella pneumoniae and E. coli in neonates < 30 weeks who received ABT the oral flora were mainly coagulase-negative staphylococci. Oral colonization with anearobes was zero and colonization with fungi was minimal.
Conclusions: Acquistion of oral bacteria rose from day 1 to day 10 of life, regardless of gestational life or ABT. On day 10 of life, the spectrum of oral bacterial flora changed following ABT and consisted mainly of coagulase-negative Staphylococcus and non E. coli garm-negative bacteria. Oral colonization showed few fungi but no anaerobes. These microbiologic observations merit attention when empirical anti-microbial therapy is considered in premature infants suspected or having late-onset sepsis.