Peptidoglycan N-acetylglucosamine deacetylation decreases autolysis in Lactococcus lactis

Meyrand, Mickaël; Boughammoura, Aïda; Courtin, Pascal; Mézange, Christine; Guillot, Alain; Chapot‐Chartier, Marie‐Pierre

doi:10.1099/mic.0.2007/005835-0

Cited by 73 publications

(67 citation statements)

References 43 publications

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“…Because complementation of the mutant restores both of these phenotypes, we hypothesize that the increased buoyancy of Dpdi liquid cultures and the inability to form chains are due to the loss of Pdi function at the S. iniae cell surface. A peptidoglycan deacetylase in Lactococcus lactis that affects chain length morphology and resistance to lysozyme killing also protects against cell autolysis (Meyrand et al, 2007). However, we were unable to detect any differences in autolysis.…”

Section: Discussioncontrasting

confidence: 46%

The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae

et al. 2010

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The aquatic zoonotic pathogen Streptococcus iniae represents a threat to the worldwide aquaculture industry and poses a risk to humans who handle raw fish. Because little is known about the mechanisms of S. iniae pathogenesis or virulence factors, we established a highthroughput system combining whole-genome pyrosequencing and transposon mutagenesis that allowed us to identify virulence proteins, including Pdi, the polysaccharide deacetylase of S. iniae, that we describe here. Using bioinformatics tools, we identified a highly conserved signature motif in Pdi that is also conserved in the peptidoglycan deacetylase PgdA protein family. A Dpdi mutant was attenuated for virulence in the hybrid striped bass model and for survival in whole fish blood. Moreover, Pdi was found to promote bacterial resistance to lysozyme killing and the ability to adhere to and invade epithelial cells. On the other hand, there was no difference in the autolytic potential, resistance to oxidative killing or resistance to cationic antimicrobial peptides between S. iniae wild-type and Dpdi. In conclusion, we have demonstrated that pdi is involved in S. iniae adherence and invasion, lysozyme resistance and survival in fish blood, and have shown that pdi plays a role in the pathogenesis of S. iniae. Identification of Pdi and other S. iniae virulence proteins is a necessary initial step towards the development of appropriate preventive and therapeutic measures against diseases and economic losses caused by this pathogen. INTRODUCTIONIn the past few decades, the pathogen Streptococcus iniae has emerged as a major hindrance to aquaculture operations worldwide (Agnew & Barnes, 2007), causing economic losses measured in hundreds of millions of dollars annually. In addition, S. iniae has established itself as a zoonotic risk, especially in areas of the world that preferentially prepare and consume raw fish (Lau et al., 2003). To date, at least 25 human cases of invasive streptococcal infection attributed to S. iniae have been confirmed in the USA, Canada, China and Taiwan, many of which were in immunocompromised patients (Agnew & Barnes, 2007;Sun et al., 2007;Weinstein et al., 1997); since there is currently no prospective epidemiological surveillance for human S. iniae infections, the true number may be much higher (Facklam et al., 2005;Lau et al., 2006).In spite of the economic and human health risks that S. iniae presents, a fully assembled genome sequence for this emerging pathogen is not yet available, and very little is known about its disease mechanisms. To better understand the molecular genetic basis of virulence in this versatile pathogen, we created a library of randomly generated transposon mutants that we screened for virulence Abbreviations: AMP, antimicrobial peptide; HSB, hybrid striped bass, i.p., intraperitoneal; PIA, polysaccharide intercellular adhesin, WT, wild-type.3These authors contributed equally to this work.The GenBank/EMBL/DDBJ accession number for the pdi sequence of Streptococcus iniae is FJ664396.Four supplementary f...

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Section: Discussioncontrasting

confidence: 46%

The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae

et al. 2010

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“…many peaks were shifted by 2 ϫ 42 mass units after the PG was chemically N-acetylated, indicating they gained two acetyl groups. As demonstrated in other bacteria, the primary location of PG N-deacetylation would be GlcNAc residues (8,26,(32)(33)(34). The deacetylation could also be on MurNAc residues, hypothesized to be the function of a PG deacetylase PdaA in B. subtilis (25).…”

Section: Discussionmentioning

confidence: 99%

“…Bacteria have developed strategies to counteract the hydrolytic activity of lysozyme by modification of their PG, preventing the binding of lysozyme to the polysaccharide substrate. Two main types of PG modification conferring lysozyme resistance have been characterized for different species of bacteria as follows: O-acetylation occurring on the C-6 hydroxyl moiety of the MurNAc residues (27,36) and N-deacetylation of the GlcNAc residues (8,26,33,34). Most of these were studied in Gram-positive bacteria, and the genes responsible for these activities are oatA (for O-acetyltransferase) and pgdA (for PG N-deacetylase), respectively.…”

Section: Parent Strain Hp310:kanmentioning

confidence: 99%

Oxidative Stress-induced Peptidoglycan Deacetylase in Helicobacter pylori

Wang

Olczak

Forsberg

et al. 2009

Journal of Biological Chemistry

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Structural modification of peptidoglycan (PG) is one of the mechanisms that pathogenic bacteria use to evade the host innate immune system. For the noninvasive human gastric pathogen Helicobacter pylori, PG delivery to the host cells is one trigger of the immune response. H. pylori HP310 was markedly up-expressed upon cell exposure to oxidative stress. However, disruption of HP310 did not produce a phenotype distinguishable from the parent, including oxidative stress resistance characteristics. HP310 shows very weak homology to a known gene pgdA encoding PG deacetylase in Streptococcous pneumoniae. PGs from wild type H. pylori and the HP310 mutant were purified and analyzed by matrix-assisted laser desorption ionization time-of-flight and high pressure liquid chromatography. The parent strain PG is partially deacetylated, whereas several major PGdeacetylated muropeptides are absent or significantly reduced in the HP310 mutant. PG deacetylase activity was directly demonstrated by use of pure PG and HP310 protein by measuring the release of acetic acid. The Gram-negative bacterium H. pylori is highly resistant to lysozyme (up to 50 mg/ml), but the HP310 mutant is less resistant to lysozyme compared with the parent strain. Complementation of an hp310 strain with the wild type gene restored lysozyme resistance. The purified PG from the mutant is more susceptible to lysozyme (0.3 mg/ml) digestion than the wild type PG. The PG deacetylation appears to confer lysozyme resistance to escape immune detection. HP310 is representative of a new subfamily of bacterial PG deacetylases.Helicobacter pylori, a pathogenic bacterium infecting over 50% of humans, is the etiological agent for gastritis, peptic ulcer, and gastric cancer (1). H. pylori is highly adapted to its ecologic niche, the human gastric mucosa. The pathogenesis of H. pylori relies on its persistence in surviving a harsh environment, including acidity, peristalsis, and attack by phagocyte cells and their released reactive oxygen species (ROS) 2 (2). H. pylori has a unique array of features that permit entry into the mucus, attachment to epithelial cells, evasion of the immune response, and as a result, persistent colonization and transmission. Numerous virulence factors in H. pylori have been extensively studied, including urease, flagella, BabA adhesin, the vacuolating cytotoxin (VacA), and the cag pathogenicity island (cag-PAI). Peptidoglycan (PG) was found in recent years to be an important factor involved in virulence by pathogenic bacteria (3). PG is one of the main protective barriers in the bacterial cell wall. PG consists of glycan strands made of alternating ␤-1,4-linked N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc), which are cross-linked by short peptide chains. In mammalian cells, a group of pattern recognition molecules (Nod1 and Nod2) can sense bacterial PG degradation products (muropeptides), initiating innate immune responses (4, 5). For example, human Nod1 (Toll-like receptor) specifically detects a unique (GlcNAc-MurNAc) tripept...

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“…Значительную роль в процессе адсорбции фагов на бактериальных клетках играет ионный состав среды, изменение пептидогликана клеточной стенки бактерии. Установлено, что фаги молочнокислых стрептококков нуждаются в кофакторах адсорбции, например, Ca 2+ (Collins, Nelson, 1950;Lawrence, Thomas, 1976;Meyrand, 2007). Однако, ряд данных свидетельствуют, что некоторые бактериофаги не нуждаются в ионах Ca 2+ и растут в бескальциевой среде .…”

Section: изучение разнообразия ассоциаций фаговunclassified

Изучение Разнообразия Ассоциаций Фагов Гомологичных Молочнокислым Бактериям

Odegov¹,

Dorofeev²,

Иркитова³

et al. 2017

Ukr J Ecol

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Information on the ecology of the "phage-bacterial host" system is given. The interaction of cultures of lactococci from the collection of the Siberian Research Institute of Cheese with associations of phages was investigated. Infection of sensitive cells with bacteriophage led to cell lysis, which was manifested by negative colonies on the lawn of a lactococcal culture. Characteristics of the biological properties of bacteriophages in the composition of phage associations are given (lytic activity, spectrum of lytic activity, specificity of action). Differentiation of species lysotypes of bacteriophages of mesophilic lactococci, selected at a single cheese enterprise in the Altai Territory was noted. The index of the lytic activity of the investigated phage associations ranged from 0.19 (sample of Lactococcus lactis subsp. Lactis biovar diacetylactis) to 0.24 (sample of Lactococcus lactis subsp. Lactis) from studied strains. The value of the lyotype updated coefficient for the entire array of data varied from 0.25 to 1.00. It is concluded that the specificity of cheese biotechnology together with the evolutionary and genetic determinants of the microworld predetermine a constant high risk of cell phagolysis of starter cultures. Experimental studies confirmed the need to consider the phagocyte of lactic acid bacteria in biotechnology. Приведены сведения по экологии системы «фаг-бактериальный хозяин». Исследовано взаимодействия культур лактококков из коллекции Сибирского НИИ сыроделия с ассоциациями фагов. Инфицирование чувствительных клеток бактериофагом приводило к лизису клеток, проявившееся негативными колониями на газоне культуры лактококка. Дана характеристика биологических свойств бактериофагов в составе фаговых ассоциаций (литическая активность, спектр литической активности, специфичность действия). Отмечена дифференциация видовых лизотипов бактериофагов мезофильных лактококков, отобранных на одном сыродельном предприятии в Алтайском крае.Индекс литической активности исследуемых фаговых ассоциаций находится в пределах от 0,19 (выборка Lactococcus lactis subsp. lactis biovar diacetylactis) до 0,24 (выборка Lactococcus lactis subsp. lactis) из числа исследуемых штаммов.Величина коэффициента обновления лизотипа для всего полученного массива данных варьировала в диапазоне от

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Peptidoglycan N-acetylglucosamine deacetylation decreases autolysis in Lactococcus lactis

Cited by 73 publications

References 43 publications

The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae

The novel polysaccharide deacetylase homologue Pdi contributes to virulence of the aquatic pathogen Streptococcus iniae

Oxidative Stress-induced Peptidoglycan Deacetylase in Helicobacter pylori

Изучение Разнообразия Ассоциаций Фагов Гомологичных Молочнокислым Бактериям

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