Do medical students studying in the United Kingdom have an adequate factual knowledge of basic life support?

BACKGROUND: Healthcare professionals have a duty to maintain basic life support (BLS) skills. This study aims to evaluate medical students' factual knowledge of BLS and the training they receive. METHODS: A cross-sectional, closed-response questionnaire was distributed to the first- and fourth-year students studying at institutions in the United Kingdom. The paper questionnaire sought to quantify respondent's previous BLS training, factual knowledge of the BLS algorithm using five multiple choice questions (MCQs), and valuate their desire for further BLS training. Students received 1 point for each correctly identified answer to the 5 MCQ's. RESULTS: A total of 3,732 complete responses were received from 21 medical schools. Eighty percent (n=2,999) of students completed a BLS course as part of their undergraduate medical studies. There was a significant difference (P<0.001) in the percentage of the fourth-year students selecting the correct answer in all the MCQ's compared to the first-year students except in identifying the correct depth of compressions required during CPR (P=0.095). Overall 10.3% (95% CI 9.9% to 10.7%) of respondents correctly identified the answer to 5 MCQ's on BLS 9% of the first-year students (n=194) and 12% of the fourth-year students (n=190). On an institutional level the proportion of students answering all MCQ's correctly ranged from 2% to 54% at different universities. Eighty-one percent of students (n=3,031) wished for more BLS training in their curriculum. CONCLUSION: Factual knowledge of BLS is poor among medical students in the UK. There is a disparity in standards of knowledge across institutions and respondents indicating that they would like more training.

Discovery of genes required for lipoteichoic acid glycosylation predicts two distinct mechanisms for wall teichoic acid glycosylation.

The bacterial cell wall is an important and highly complex structure that is essential for bacterial growth because it protects bacteria from cell lysis and environmental insults. A typical Gram-positive bacterial cell wall is composed of peptidoglycan and the secondary cell wall polymers, wall teichoic acid (WTA) and lipoteichoic acid (LTA). In many Gram-positive bacteria, LTA is a polyglycerol-phosphate chain that is decorated with d-alanine and sugar residues. However, the function of and proteins responsible for the glycosylation of LTA are either unknown or not well-characterized. Here, using bioinformatics, genetic, and NMR spectroscopy approaches, we found that the Bacillus subtilis csbB and yfhO genes are essential for LTA glycosylation. Interestingly, the Listeria monocytogenes gene lmo1079, which encodes a YfhO homolog, was not required for LTA glycosylation, but instead was essential for WTA glycosylation. LTA is polymerized on the outside of the cell and hence can only be glycosylated extracellularly. Based on the similarity of the genes coding for YfhO homologs that are required in B. subtilis for LTA glycosylation or in L. monocytogenes for WTA glycosylation, we hypothesize that WTA glycosylation might also occur extracellularly in Listeria species. Finally, we discovered that in L. monocytogenes, lmo0626 (gtlB) was required for LTA glycosylation, indicating that the encoded protein has a function similar to that of YfhO, although the proteins are not homologous. Together, our results enable us to propose an updated model for LTA glycosylation and also indicate that glycosylation of WTA might occur through two different mechanisms in Gram-positive bacteria.

Identification of a Lipoteichoic Acid Glycosyltransferase Enzyme Reveals that GW-Domain-Containing Proteins Can Be Retained in the Cell Wall of Listeria monocytogenes in the Absence of Lipoteichoic Acid or Its Modifications.

UNLABELLED: Listeria monocytogenes is a foodborne Gram-positive bacterial pathogen, and many of its virulence factors are either secreted proteins or proteins covalently or noncovalently attached to the cell wall. Previous work has indicated that noncovalently attached proteins with GW (glycine-tryptophan) domains are retained in the cell wall by binding to the cell wall polymer lipoteichoic acid (LTA). LTA is a glycerol phosphate polymer, which is modified in L. monocytogenes with galactose and d-alanine residues. We identified Lmo0933 as the cytoplasmic glycosyltransferase required for the LTA glycosylation process and renamed the protein GtlA, for glycosyltransferase LTA A Using L. monocytogenes mutants lacking galactose or d-alanine modifications or the complete LTA polymer, we show that GW domain proteins are retained within the cell wall, indicating that other cell wall polymers are involved in the retention of GW domain proteins. Further experiments revealed peptidoglycan as the binding receptor as a purified GW domain fusion protein can bind to L. monocytogenes cells lacking wall teichoic acid (WTA) as well as purified peptidoglycan derived from a wild-type or WTA-negative strain. With this, we not only identify the first enzyme involved in the LTA glycosylation process, but we also provide new insight into the binding mechanism of noncovalently attached cell wall proteins. IMPORTANCE: Over the past 20 years, a large number of bacterial genome sequences have become available. Computational approaches are used for the genome annotation and identification of genes and encoded proteins. However, the function of many proteins is still unknown and often cannot be predicted bioinformatically. Here, we show that the previously uncharacterized Listeria monocytogenes gene lmo0933 likely codes for a glycosyltransferase required for the decoration of the cell wall polymer lipoteichoic acid (LTA) with galactose residues. Using L. monocytogenes mutants lacking LTA modifications or the complete polymer, we show that specific cell wall proteins, often associated with virulence, are retained within the cell wall, indicating that additional cell wall polymers are involved in their retention.

Structural and mechanistic insight into the Listeria monocytogenes two-enzyme lipoteichoic acid synthesis system.

Lipoteichoic acid (LTA) is an important cell wall component required for proper cell growth in many Gram-positive bacteria. In Listeria monocytogenes, two enzymes are required for the synthesis of this polyglycerolphosphate polymer. The LTA primase LtaP(Lm) initiates LTA synthesis by transferring the first glycerolphosphate (GroP) subunit onto the glycolipid anchor and the LTA synthase LtaS(Lm) extends the polymer by the repeated addition of GroP subunits to the tip of the growing chain. Here, we present the crystal structures of the enzymatic domains of LtaP(Lm) and LtaS(Lm). Although the enzymes share the same fold, substantial differences in the cavity of the catalytic site and surface charge distribution contribute to enzyme specialization. The eLtaS(Lm) structure was also determined in complex with GroP revealing a second GroP binding site. Mutational analysis confirmed an essential function for this binding site and allowed us to propose a model for the binding of the growing chain.

Lipoteichoic acid synthesis and function in gram-positive bacteria.

Lipoteichoic acid (LTA) is an important cell wall polymer found in gram-positive bacteria. Although the exact role of LTA is unknown, mutants display significant growth and physiological defects. Additionally, modification of the LTA backbone structure can provide protection against cationic antimicrobial peptides. This review provides an overview of the different LTA types and their chemical structures and synthesis pathways. The occurrence and mechanisms of LTA modifications with D-alanyl, glycosyl, and phosphocholine residues will be discussed along with their functions. Similarities between the production of type I LTA and osmoregulated periplasmic glucans in gram-negative bacteria are highlighted, indicating that LTA should perhaps be compared to these polymers rather than lipopolysaccharide, as is presently the case. Lastly, current efforts to use LTAs as vaccine candidates, synthesis proteins as novel antimicrobial targets, and LTA mutant strains as improved probiotics are highlighted.