Battling Collateral Consequences: The Long Road to Redemption

Mississippi Governor Haley Barbour issued 193 controversial pardons on January 10, 2012, his last day in office. Former Ohio Governor Ted Strickland, who left office in January 2011, also faced criticism when he granted 280 pardons. Both governors publicly acknowledged that they granted most of their pardons to rehabilitated ex-offenders who sought to overcome the civil consequences of their criminal convictions. These consequences, known as collateral consequences, impede the ability of millions of ex-offenders to find employment, housing or other important benefits. This Article explores the increasingly important, but controversial, role that governors play in the battleground of collateral consequences. Their use of their redemptive pardon power has become critical to ex-offenders to overcome the collateral consequences of their convictions so they may reintegrate into society. This Article examines the redemptive pardon process through the lens of two ex-offenders who made the journey from conviction to pardon. As their stories reveal, the pardon process is long and arduous. This Article recommends that governors adopt an expedited process for redemptive pardons so ex-offenders may have more timely relief from the burden of their collateral consequences. The redemptive pardon serves an important role for ex-offenders who seek a second chance, but it is impossible for governors to consider and to grant the pardon applications of millions of ex-offenders. States must offer other remedies to ex-offenders that can also serve to ameliorate the impact of collateral consequences. This Article recommends changes to judicial expungement statutes, using Ohio as a model, to offer this needed relief. The redemptive pardon and judicial expungement process will help ex-offenders in their ongoing struggle with the collateral consequences of their convictions, but true relief can only occur if there is an end to collateral consequences. This Article urges states to abolish collateral consequences and it highlights Ohio’s efforts as a model for this change

Influence of Amino Acid Substitutions in the Nisin Leader Peptide on Biosynthesis and Secretion of Nisin by Lactococcus lactis

Structural genes for small lanthionine-containing antimicrobial peptides, known as lantibiotics, encode N-terminal leader sequences which are not present in the mature peptide, but are cleaved off at some stage in the maturation process. Leader sequences of the different lantibiotics share a number of identical amino acid residues, but they are clearly different from sec-dependent protein export signal sequences. We studied the role of the leader sequence of the lantibiotic nisin, which is produced and secreted by Lactococcus lactis, by creating site-directed mutations at various positions in the leader peptide sequence. Mutations at Arg-1 and Ala-4, but not at the conserved Pro-2, strongly affected the processing of the leader sequence and resulted in the extracellular accumulation of a biologically inactive precursor peptide. Amino acid analysis and 1H NMR studies indicated that the precursor peptide with an Ala-4 → Asp mutation contained a modified nisin structural part with the (mutated) unmodified leader sequence still attached to it. The Ala-4 → Asp precursor peptide could be activated in vitro by enzymatic cleavage with trypsin, liberating nisin. These results confirmed that cleavage of the leader peptide is the last step in nisin maturation and is necessary to generate a biologically active peptide. Several mutations, i.e. Pro-2 → Gly, Pro-2 → Val, Asp-7 → Ala, Lys-9 → Leu, Ser-10 → Ala/Ser-12 → Ala and Val-11 → Asp/Val-13 → Glu in the leader peptide did not have any detectable effect on nisin production and secretion, although some of them affected highly conserved residues. When mutations were created in the -18 to -15 region of the nisin leader peptide (i.e. Phe-18 → Leu, Leu-16 → Lys, Asp-15 → Ala), no secretion or intracellular accumulation could be detected of nisin or its precursors. This suggested that these conserved residues are involved in the maturation process and may interact with lantibiotic-specific modifying enzymes.

The Lantibiotic Nisin Induces Lipid II Aggregation, Causing Membrane Instability and Vesicle Budding

AbstractThe antimicrobial peptide nisin exerts its activity by a unique dual mechanism. It permeates the cell membranes of Gram-positive bacteria by binding to the cell wall precursor Lipid II and inhibits cell wall synthesis. Binding of nisin to Lipid II induces the formation of large nisin-Lipid II aggregates in the membrane of bacteria as well as in Lipid II-doped model membranes. Mechanistic details of the aggregation process and its impact on membrane permeation are still unresolved. In our experiments, we found that fluorescently labeled nisin bound very inhomogeneously to bacterial membranes as a consequence of the strong aggregation due to Lipid II binding. A correlation between cell membrane damage and nisin aggregation was observed in vivo. To further investigate the aggregation process of Lipid II and nisin, we assessed its dynamics by single-molecule microscopy of fluorescently labeled Lipid II molecules in giant unilamellar vesicles using light-sheet illumination. We observed a continuous reduction of Lipid II mobility due to a steady growth of nisin-Lipid II aggregates as a function of time and nisin concentration. From the measured diffusion constants of Lipid II, we estimated that the largest aggregates contained tens of thousands of Lipid II molecules. Furthermore, we observed that the formation of large nisin-Lipid II aggregates induced vesicle budding in giant unilamellar vesicles. Thus, we propose a membrane permeation mechanism that is dependent on the continuous growth of nisin-Lipid II aggregation and probably involves curvature effects on the membrane

Evolution of a pathogen: a comparative genomics analysis identifies a genetic pathway to pathogenesis in acinetobacter.

Acinetobacter baumannii is an emergent and global nosocomial pathogen. In addition to A. baumannii, other Acinetobacter species, especially those in the Acinetobacter calcoaceticus-baumannii (Acb) complex, have also been associated with serious human infection. Although mechanisms of attachment, persistence on abiotic surfaces, and pathogenesis in A. baumannii have been identified, the genetic mechanisms that explain the emergence of A. baumannii as the most widespread and virulent Acinetobacter species are not fully understood. Recent whole genome sequencing has provided insight into the phylogenetic structure of the genus Acinetobacter. However, a global comparison of genomic features between Acinetobacter spp. has not been described in the literature. In this study, 136 Acinetobacter genomes, including 67 sequenced in this study, were compared to identify the acquisition and loss of genes in the expansion of the Acinetobacter genus. A whole genome phylogeny confirmed that A. baumannii is a monophyletic clade and that the larger Acb complex is also a well-supported monophyletic group. The whole genome phylogeny provided the framework for a global genomic comparison based on a blast score ratio (BSR) analysis. The BSR analysis demonstrated that specific genes have been both lost and acquired in the evolution of A. baumannii. In addition, several genes associated with A. baumannii pathogenesis were found to be more conserved in the Acb complex, and especially in A. baumannii, than in other Acinetobacter genomes; until recently, a global analysis of the distribution and conservation of virulence factors across the genus was not possible. The results demonstrate that the acquisition of specific virulence factors has likely contributed to the widespread persistence and virulence of A. baumannii. The identification of novel features associated with transcriptional regulation and acquired by clades in the Acb complex presents targets for better understanding the evolution of pathogenesis and virulence in the expansion of the genus

Using Whole Genome Analysis to Examine Recombination across Diverse Sequence Types of Staphylococcus aureus

Staphylococcus aureus is an important clinical pathogen worldwide and understanding this organism\u27s phylogeny and, in particular, the role of recombination, is important both to understand the overall spread of virulent lineages and to characterize outbreaks. To further elucidate the phylogeny of S. aureus, 35 diverse strains were sequenced using whole genome sequencing. In addition, 29 publicly available whole genome sequences were included to create a single nucleotide polymorphism (SNP)-based phylogenetic tree encompassing 11 distinct lineages. All strains of a particular sequence type fell into the same clade with clear groupings of the major clonal complexes of CC8, CC5, CC30, CC45 and CC1. Using a novel analysis method, we plotted the homoplasy density and SNP density across the whole genome and found evidence of recombination throughout the entire chromosome, but when we examined individual clonal lineages we found very little recombination. However, when we analyzed three branches of multiple lineages, we saw intermediate and differing levels of recombination between them. These data demonstrate that in S. aureus, recombination occurs across major lineages that subsequently expand in a clonal manner. Estimated mutation rates for the CC8 and CC5 lineages were different from each other. While the CC8 lineage rate was similar to previous studies, the CC5 lineage was 100-fold greater. Fifty known virulence genes were screened in all genomes in silico to determine their distribution across major clades. Thirty-three genes were present variably across clades, most of which were not constrained by ancestry, indicating horizontal gene transfer or gene loss

Draft genome sequences of two Bulgarian Bacillus anthracis strains

Bacillus anthracis strains previously isolated from Bulgaria form a unique subcluster within the A1.a cluster that is typical for isolates from southeastern Europe. Here, we report the draft genome sequences of two Bulgarian B. anthracis strains belonging to the A branch (A.Br.) 008/009 canonical single nucleotide polymorphism (SNP) group of the major A branch