Surgical outcomes of intraocular lens iris suture fixation in eyes with residual capsule support.

Purpose: To evaluate the safety and refractive outcomes of eyes after intraocular lens (IOL) iris suture fixation (ISF).

Setting: Private practice, Los Angeles, California.

Design: Nonrandomized and unmasked retrospective chart review.

pSK41/pGO1-family conjugative plasmids of Staphylococcus aureus encode a cryptic repressor of replication.

The majority of large multiresistance plasmids of Staphylococcus aureus utilise a RepA_N-type replication initiation protein, the expression of which is regulated by a small antisense RNA (RNAI) that overlaps the rep mRNA leader. The pSK41/pGO1-family of conjugative plasmids additionally possess a small (86 codon) divergently transcribed ORF (orf86) located upstream of the rep locus. The product of pSK41 orf86 was predicted to have a helix-turn-helix motif suggestive of a likely function in transcriptional repression.

The Plasmidomic Landscape of Clinical Methicillin-Resistant Isolates from Malaysia.

Methicillin-resistant (MRSA) is a priority nosocomial pathogen with plasmids playing a crucial role in its genetic adaptability, particularly in the acquisition and spread of antimicrobial resistance. In this study, the genome sequences of 79 MSRA clinical isolates from Terengganu, Malaysia, (obtained between 2016 and 2020) along with an additional 15 Malaysian MRSA genomes from GenBank were analyzed for their plasmid content. The majority (90%, 85/94) of the Malaysian MRSA isolates harbored 1-4 plasmids each.

Complete Genome Sequence and Analysis of a ST573 Multidrug-Resistant Methicillin-Resistant SauR3 Clinical Isolate from Terengganu, Malaysia.

Methicillin-resistant (MRSA) is a World Health Organization-listed priority pathogen. Scarce genomic data are available for MRSA isolates from Malaysia. Here, we present the complete genome sequence of a multidrug-resistant MRSA strain SauR3, isolated from the blood of a 6-year-old patient hospitalized in Terengganu, Malaysia, in 2016.

Comparative Genomic Analysis of a Multidrug-Resistant ShoR14 Clinical Isolate from Terengganu, Malaysia, Led to the Discovery of Novel Mobile Genetic Elements.

is a coagulase-negative (CoNS) commensal capable of causing serious systemic infections in humans. The emergence of multidrug-resistant strains is of concern but little is known about the characteristics of this organism, particularly from Malaysia. Here, we present the comparative genome analysis of ShoR14, a multidrug-resistant, methicillin-resistant blood isolate from Terengganu, Malaysia.

Evolving origin-of-transfer sequences on staphylococcal conjugative and mobilizable plasmids-who's mimicking whom?

In Staphylococcus aureus, most multiresistance plasmids lack conjugation or mobilization genes for horizontal transfer. However, most are mobilizable due to carriage of origin-of-transfer (oriT) sequences mimicking those of conjugative plasmids related to pWBG749. pWBG749-family plasmids have diverged to carry five distinct oriT subtypes and non-conjugative plasmids have been identified that contain mimics of each.

Surgical management of positive dysphotopsia: U.S. perspective.

Purpose: To evaluate clinical outcomes of intraocular lens (IOL) exchange for intolerable positive dysphotopsia (PD).

Setting: Private practice, Advanced Vision Care, Los Angeles, California, USA.

Design: Retrospective review, case series.

Evolution of a 72-Kilobase Cointegrant, Conjugative Multiresistance Plasmid in Community-Associated Methicillin-Resistant Staphylococcus aureus Isolates from the Early 1990s.

Horizontal transfer of plasmids encoding antimicrobial resistance and virulence determinants has been instrumental in evolution, including the emergence of community-associated methicillin-resistant (CA-MRSA). In the early 1990s, the first CA-MRSA strain isolated in Western Australia (WA), WA-5, encoded cadmium, tetracycline, and penicillin resistance genes on plasmid pWBG753 (∼30 kb). WA-5 and pWBG753 appeared only briefly in WA; however, fusidic acid resistance plasmids related to pWBG753 were also present in the first European CA-MRSA isolates at the time.

Staphylococcal Plasmids, Transposable and Integrative Elements.

Strains of , and to a lesser extent other staphylococcal species, are a significant cause of morbidity and mortality. An important factor in the notoriety of these organisms stems from their frequent resistance to many antimicrobial agents used for chemotherapy. This review catalogues the variety of mobile genetic elements that have been identified in staphylococci, with a primary focus on those associated with the recruitment and spread of antimicrobial resistance genes.

Construction of Challenging Proline-Proline Junctions via Diselenide-Selenoester Ligation Chemistry.

Polyproline sequences are highly abundant in prokaryotic and eukaryotic proteins, where they serve as key components of secondary structure. To date, construction of the proline-proline motif has not been possible owing to steric congestion at the ligation junction, together with an n → π* electronic interaction that reduces the reactivity of acylated proline residues at the C-terminus of peptides. Here, we harness the enhanced reactivity of prolyl selenoesters and a trans-γ-selenoproline moiety to access the elusive proline-proline junction for the first time through a diselenide-selenoester ligation-deselenization manifold.

Mobile Genetic Elements Associated with Antimicrobial Resistance.

Strains of bacteria resistant to antibiotics, particularly those that are multiresistant, are an increasing major health care problem around the world. It is now abundantly clear that both Gram-negative and Gram-positive bacteria are able to meet the evolutionary challenge of combating antimicrobial chemotherapy, often by acquiring preexisting resistance determinants from the bacterial gene pool. This is achieved through the concerted activities of mobile genetic elements able to move within or between DNA molecules, which include insertion sequences, transposons, and gene cassettes/integrons, and those that are able to transfer between bacterial cells, such as plasmids and integrative conjugative elements.

Replication of Staphylococcal Resistance Plasmids.

The currently widespread and increasing prevalence of resistant bacterial pathogens is a significant medical problem. In clinical strains of staphylococci, the genetic determinants that confer resistance to antimicrobial agents are often located on mobile elements, such as plasmids. Many of these resistance plasmids are capable of horizontal transmission to other bacteria in their surroundings, allowing extraordinarily rapid adaptation of bacterial populations.

An updated view of plasmid conjugation and mobilization in Staphylococcus.

The horizontal gene transfer facilitated by mobile genetic elements impacts almost all areas of bacterial evolution, including the accretion and dissemination of antimicrobial-resistance genes in the human and animal pathogen Staphylococcus aureus. Genome surveys of staphylococcal plasmids have revealed an unexpected paucity of conjugation and mobilization loci, perhaps suggesting that conjugation plays only a minor role in the evolution of this genus. In this letter we present the DNA sequences of historically documented staphylococcal conjugative plasmids and highlight that at least 3 distinct and widely distributed families of conjugative plasmids currently contribute to the dissemination of antimicrobial resistance in Staphylococcus.

Processing of Nonconjugative Resistance Plasmids by Conjugation Nicking Enzyme of Staphylococci.

Unlabelled: Antimicrobial resistance in Staphylococcus aureus presents an increasing threat to human health. This resistance is often encoded on mobile plasmids, such as pSK41; however, the mechanism of transfer of these plasmids is not well understood. In this study, we first examine key protein-DNA interactions formed by the relaxase enzyme, NES, which initiates and terminates the transfer of the multidrug resistance plasmid pSK41.

Structural and sequence requirements for the antisense RNA regulating replication of staphylococcal multiresistance plasmid pSK41.

pSK41 is a prototypical 46-kb conjugative multiresistance plasmid of Staphylococcus aureus. The pSK41 replication initiation protein (Rep) is rate-limiting for plasmid replication, and its expression is negatively regulated by a small, non-coding antisense transcript, RNAI, that is complementary to the rep mRNA leader region. In this study, enzymatic probing was used to verify the predicted secondary structures of RNAI and its target RNA.

Mechanism of staphylococcal multiresistance plasmid replication origin assembly by the RepA protein.

The staphylococcal multiresistance plasmids are key contributors to the alarming rise in bacterial multidrug resistance. A conserved replication initiator, RepA, encoded on these plasmids is essential for their propagation. RepA proteins consist of flexibly linked N-terminal (NTD) and C-terminal (CTD) domains.

Staphylococcus aureus surface proteins involved in adaptation to oxacillin identified using a novel cell shaving approach.

Staphylococcus aureus is a Gram-positive pathogen responsible for a variety of infections, and some strains are resistant to virtually all classes of antibiotics. Cell shaving proteomics using a novel probability scoring algorithm to compare the surfaceomes of the methicillin-resistant, laboratory-adapted S. aureus COL strain with a COL strain in vitro adapted to high levels of oxacillin (APT).

Biology of the staphylococcal conjugative multiresistance plasmid pSK41.

Plasmid pSK41 is a large, low-copy-number, conjugative plasmid from Staphylococcus aureus that is representative of a family of staphylococcal plasmids that confer multiple resistances to a wide range of antimicrobial agents. The plasmid consists of a conserved plasmid backbone containing the genes for plasmid housekeeping functions, which is punctuated by copies of IS257 that flank a Tn4001-hybrid structure and cointegrated plasmids that harbour resistance genes. This review summarises the current understanding of the biology of pSK41, focussing on the systems responsible for its replication, maintenance and transmission, and their regulation.

Molecular basis of antibiotic multiresistance transfer in Staphylococcus aureus.

Multidrug-resistant Staphylococcus aureus infections pose a significant threat to human health. Antibiotic resistance is most commonly propagated by conjugative plasmids like pLW1043, the first vancomycin-resistant S. aureus vector identified in humans.

Genetic requirements for replication initiation of the staphylococcal multiresistance plasmid pSK41.

Replication of staphylococcal multiresistance plasmid pSK41 is initiated by binding of the replication initiator protein (Rep) to the Rep boxes, a series of four direct repeats located centrally within the rep gene. A Staphylococcus aureus strain was engineered to provide Rep in trans, allowing localization of the pSK41 origin of replication (oriV) to a 185 bp segment, which included the Rep boxes and a series of downstream direct repeats. Deletion analysis of individual Rep boxes revealed that all four Rep boxes are required for maximum origin activity, with the deletion of one or more Rep boxes having a significant effect on the proficiency of replication.

Analysis of the prototypical Staphylococcus aureus multiresistance plasmid pSK1.

The Staphylococcus aureus multiresistance plasmid pSK1 is the prototype of a family of structurally related plasmids that were first identified in epidemic S. aureus strains isolated in Australia during the 1980s and subsequently in Europe. Here we present the complete 28.

Complete nucleotide sequence and comparative analysis of pPR9, a 41.7-kilobase conjugative staphylococcal multiresistance plasmid conferring high-level mupirocin resistance.

We have sequenced the conjugative plasmid pPR9, which carries the ileS2 gene, which had contributed to the dissemination of high-level mupirocin resistance at our institution. The plasmid backbone shows extensive genetic conservation with plasmids belonging to the pSK41/pGO1 family, but comparative analyses have revealed key differences that provide important insights into the evolution of these medically important plasmids and high-level mupirocin resistance in staphylococci and highlight the role of insertion sequence IS257 in these processes.

The Staphylococcus aureus pSK41 plasmid-encoded ArtA protein is a master regulator of plasmid transmission genes and contains a RHH motif used in alternate DNA-binding modes.

Plasmids harbored by Staphylococcus aureus are a major contributor to the spread of bacterial multi-drug resistance. Plasmid conjugation and partition are critical to the dissemination and inheritance of such plasmids. Here, we demonstrate that the ArtA protein encoded by the S.