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Genetic Recombination in Bacillus subtilis 168: Contribution of Holliday Junction Processing Functions in Chromosome Segregation. Begoņa Carrasco, 2004.Bacillus subtilis mutants classified within the 
(ruvA,
 ruvB,
recU,
and recD) and
(recG)
epistatic groups, in an otherwise rec+ background,
render cells impaired in chromosomal segregation . A less-pronounced
segregation defect in
recA
and
sms
(radA)
cells was observed . The repair deficiency of addAB,
recO,
recR,
recH,
recS,
and
subA
cells did not correlate with a chromosomal segregation defect . The
sensitivity of
epistatic group mutants to DNA-damaging agents correlates with
ongoing DNA replication at the time of exposure to the agents . The
sms
(radA)
and
subA
mutations partially suppress the DNA repair defect in ruvA and
recD cells and the segregation defect in ruvA and
recG
cells . The
sms
(radA)
and
subA
mutations partially suppress the DNA repair defect of
recU
cells but do not suppress the segregation defect in these cells . The
recA
mutation suppresses the segregation defect but does not suppress the
DNA repair defect in
recU
cells . These results result suggest that (i) the RuvAB and RecG
branch migrating DNA helicases, the RecU Holliday junction (HJ)
resolvase, and RecD bias HJ resolution towards noncrossovers and that
(ii) Sms (RadA) and SubA proteins might play a role in the
stabilization and or processing of HJ intermediates .
Isolation and Analysis of Mutants of Double-Stranded-RNA Bacteriophage  6 with Altered Packaging Specificity.Jian Qiao, 2003.The genomes of bacteriophage 6 and its relatives are packaged through a mechanism that involves the recognition and translocation of the three different plus strand transcripts of the segmented double-stranded RNA genomes into preformed polyhedral structures called procapsids or inner cores . This packaging requires hydrolysis of nucleoside triphosphates and takes place in the order S-M-L . Packaging is dependent on unique sequences of about 200 nucleotides near the 5' ends of plus strand transcripts of the three genomic segments . Changes in the pac sequences lead to loss of packaging ability but can be suppressed by second-site changes in RNA or amino acid changes in protein P1, the major structural protein of the procapsid . It appears that P1 is the determinant of the RNA binding sites, and it is suggested that the binding sites overlap or are conformational changes of the same domains .
Rapid Detection of Campylobacter coli, C . jejuni, and Salmonella enterica on Poultry Carcasses by Using PCR-Enzyme-Linked Immunosorbent Assay. Yang Hong, 2003.Contamination of retail poultry by Campylobacter spp . and Salmonella enterica is a significant source of human diarrheal disease . Isolation and identification of these microorganisms require a series of biochemical and serological tests . In this study, Campylobacter ceuE and Salmonella invA genes were used to design probes in PCR-enzyme-linked immunosorbent assay (ELISA), as an alternative to conventional bacteriological methodology, for the rapid detection of Campylobacter jejuni, Campylobacter coli, and S . enterica from poultry samples . With PCR-ELISA (40 cycles), the detection limits for Salmonella and Campylobacter were 2 x 102 and 4 x 101 CFU/ml, respectively . ELISA increased the sensitivity of the conventional PCR method by 100- to 1,000-fold . DNA was extracted from carcass rinses and tetrathionate enrichments and used in PCR-ELISA for the detection of Campylobacter and S . enterica, respectively . With PCR-ELISA, Salmonella was detected in 20 of 120 (17%) chicken carcass rinses examined, without the inclusion of an enrichment step . Significant correlation was observed between PCR-ELISA and cultural methods (kappa = 0.83; chi-square test, P < 0.001) with only one false negative (1.67%) and four false positives (6.67%) when PCR-ELISA was used to screen 60 tetrathionate enrichment cultures for Salmonella . With PCR-ELISA, we observed a positive correlation between the ELISA absorbance (optical density at 405 nm) and the campylobacter cell number in carcass rinse, as determined by standard culture methods . Overall, PCR-ELISA is a rapid and cost-effective approach for the detection and enumeration of Salmonella and Campylobacter bacteria on poultry .
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