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Objective To evaluate the initial cutoff values, rates of screen positives, and genotypes for the large-scale newborn screening program for multiple mucopolysaccharidoses (MPS) in Taiwan. Study design More than 100 000 dried blood spots were collected consecutively as part of the national Taiwan newborn screening programs. Enzyme activities were measured by tandem mass spectrometry from dried blood spot punches. Genotypes were obtained when a second newborn screening specimen again had a decreased enzyme activity. Additional clinical evaluation was then initiated based on enzyme activity and/or genotype. Results Molecular genetic analysis for cases with low enzyme activity revealed 5 newborns with pathogenic alpha-L-iduronidase mutations, 3 newborns with pathogenic iduronate-2-sulfatase mutations, and 1 newborn was a carrier of an arylsulfatase B mutation. Several variants of unknown pathogenic significance were also identified, most likely causing pseudodeficiency. Conclusions The highly robust tandem mass spectrometry-based enzyme assays for MPS-I, MPS-II, and MPS-VI allow for high-throughput newborn screening for these lysosomal storage disorders. Optimized cutoff values combined with second tier testing could largely eliminate false-positive results. Accordingly, newborn screening for these lysosomal storage disorders is possible.

The fusidic acid (FUS) resistance determinants fusB, fusC, fusD and fusF in coagulase-negative staphylococci (CoNS) clinical isolates were examined. Among 208 FUS-resistant isolates, the fusB gene was the most common resistance determinant in each species, except in Staphylococcus hominis subsp. hominis or in species carrying intrinsic fusD or fusF. In S. hominis subsp. hominis, the fusC gene was the major determinant responsible for FUS resistance. To understand the genetic context of fusC in S. hominis subsp. hominis, 31 fusC-positive S. hominis subsp. hominis isolates were examined. Among these isolates, 14 carried SCCfusC, 3 carried an SCC476-like element and 7 carried a new SCC structure (SCC3390). As shown by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) analyses, the S. hominis subsp. hominis clinical isolates showed limited clonality. Taken together, SCCfusC has been found in S. hominis subsp. hominis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus capitis subsp. ureolyticus and Staphylococcus aureus, suggesting its wide distribution and spread among different species of staphylococci.

Gemella morbillorum, a low G+C content Gram-positive bacterium, is considered to be a commensal organism in humans but occasionally causes endocarditis or other diseases. We determined the sequences of groESL, dnaK and their flanking regions in G. morbillorum. Sequence analysis revealed the presence of putative CtsR binding sites in both groE and dnaK operons, but the lack of CIRCE in groE and the presence of CIRCE in dnaK. This finding suggests in addition to the known regulatory systems for the class I heat shock protein genes, there may be another model in G. morbillorum. Furthermore, an unusual organization of the groE operon as groES-groEL-trxA was found. Genome sequence on GenBank database and southern blot indicate that there is only one copy of trxA in G. morbillorum. Sequencing of the groE locus from other Gemella species and clinical isolates revealed the same genetic structure, suggesting the conservation of the structure in Gemella species. Northern hybridization revealed that there were two transcripts, a large transcript, groES-groEL-trxA and a small transcript, trxA, in groE operon. Treatment of heat or diamide increased the transcription level of groES-groEL-trxA, whereas these two stresses did not affect the small trxA transcript. Thus, this study reveals that the trxA is co-transcribed with the groE operon, and most possibly under the control of the CtsR.