The impact of the new energy crop sorghum on the weed flora

Sorghum is one of the most promising new options for the diversification of land use and for the replacement of maize in energy cropping systems. In on-farm experiments in three different regions of Germany (Thuringian Basin, East Brandenburg and the Lake District of Mecklenburg) between 2008 and 2010, we investigated if and how the cultivation of sorghum affects weed abundances and biodiversity aspects under real farming conditions. Energy maize was used as reference crop for the comparisons with sorghum. Special regard was given to test the hypothesis that differences in the weed flora between both crops can be explained by structural and temporal characteristics of the crop stands.In the field experiments, we found crop stands of sorghum and maize to have varying temporal (sowing time, growth dynamism) and structural traits (crop stands height and coverage). Hence, although sorghum shows a growth habit similar to that of maize, it is differing mainly in:i) the at least 3-4 week delayed sowing time, ii) a slow development during early growth stages,iii) a higher crop stand density and more intense shadowing at the end of the growing period.According to these particularities, we found sorghum to be very sensitive to early weed infestations. The height of early weed infestation level were in dependence of the weather conditions. The weed flora (species richness and species composition) in sorghum did not differ much from that of maize. Species composition was mainly affected by the modified sowing time. The weed species composition of the later sown sorghum differed mainly in the dominance of single weed species and the share of different ecological groups. Late summer or whole year germinating weed species like e.g. species of the Polygonaceae family may benefit specifically while Asteraceae species tend to be restricted.Keywords: Crop stand architecture, crop stand dynamism, fidelity index, general linear model, maizeEinfluss des Anbaus von Sorghumhirsen als Energiepflanzen auf die BeikrautfloraSorghumhirsen gelten als vielversprechende Alternative zur Diversifizierung des landwirtschaftlichen Anbaus und für den partiellen Ersatz von Mais im Energiepflanzenanbau. Die Konsequenzen, die sich aus dem Anbau von Sorghumhirsen für die Beikrautregulation und Biodiversitätsaspekte unter Praxisbedingungen ergeben, waren Gegenstand von dreijährigen Felduntersuchungen in drei, naturräumlich unterschiedlichen Regionen in Deutschland (Thüringer Becken, Ost-Brandenburg und Mecklenburger Seenplatte). Mais wurde für die Erhebungen als Referenzkultur genutzt. Für die Analyse der Kulturarteneffekte wurde von der Hypothese ausgegangen, dass die Unterschiede in der Beikrautflora beider Kulturarten durch zeitliche und strukturelle Merkmale der Kulturpflanzenbestände erklärt werden können.Im Ergebnis der unserer Felduntersuchungen konnte aufgezeigt werden, dass zwischen den von Sorghumhirsen und Mais gebildeten Kulturpflanzenbeständen deutliche entwicklungsdynamische und strukturelle Unterschiede bestehen. Die Bestandesentwicklung von Sorghumhirsen unterscheidet sich vom Mais vor allem in folgenden Eigenschaften:i.) einer um mindestens 3-4 Wochen späteren Aussaat,ii.) einer langsameren Jugendentwicklung,iii.) einem dichteren Bestand und einer höheren Beschattung gegen Ende der Vegetationsperiode.Auf Grund dieser Besonderheiten zeigten sich Sorghumhirsen anfälliger für Frühverunkrautungen, deren Auftreten jedoch eine starke Witterungsabhängigkeit aufwies. Die Artenzahlen und Zusammensetzung der Beikräuter unterschieden sich zwischen Sorghumhirsen und Mais nicht wesentlich. Die Artenzusammensetzung variierte vor allen in Abhängigkeit vom Saattermin. Vor allem spät oder ganzjährig keimfähige Arten u.a. der Familie Polygonaceae können von der späten Aussaat profitieren, während z.B. Vertreter der Asteraceae abnehmende Tendenzen zeigten.Stichwörter: Allgemeines lineares Modell, Bestandesarchitektur, Bestandesdynamik, Mais, Treueinde

Assessment of productivity and profitability of sole and double-cropping for agricultural biomass production

Zweifruchtsysteme werden in Deutschland als alterna­tive Anbausysteme für die landwirtschaftliche Biomasse­produktion erwogen. In dieser Untersuchung wurden die Produktivität und Wirtschaftlichkeit von Zweifruchtnutzung und Hauptfruchtanbau in den Jahren 2007 bis 2009 an drei klimatisch unterschiedlichen Standorten in Deutschland verglichen. Die wärmeliebenden Kulturen Mais (Zea mays L.), Futterhirse [Sorghum bicolor (L.) Moench] und Sudangras [S. bicolor (L.) Moench × S. sudanense (Piper) Stapf] wurden entweder allein als Hauptfrüchte oder als Zweitfrüchte nach Winterroggen (Secale cereale L.) angebaut. Bei Zweifruchtnutzung wurde der Winterroggen entweder zwischen Anfang und Mitte Mai (früh) oder Anfang Juni (spät) geerntet. Während der Winterroggen kein Zusatzwasser erhielt, wurden Mais, Futterhirse und Sudangras sowohl mit als auch ohne künstliche Bewässerung angebaut. Der Winterroggen lieferte einen oberirdischen Trockenmasseertrag von 5,2 t ha–1 bei früher Ernte und von 9,0 t ha–1 bei später Ernte. Die ertragreichste Zweifruchtnutzung (Roggen-Mais) war der produktivsten Hauptfrucht (Mais) ohne Zusatzbewässerung um 3,6 t ha–1 (23%) und mit Zusatzbewässerung um 5,2 t ha–1 (24%) überlegen. Durch die Zusatzbewässerung erhöht sich der Trockenmasseertrag bei den Hauptfrüchten um 5,3 t ha–1 (37%), bei den früh gesäten Zweitfrüchten um 5,6 t ha–1 (43%) und bei den spät gesäten Zweitfrüchten um 6,8 t ha–1 (77%). Ohne Zusatzbewässerung wurden die, im Vergleich zum Hauptfruchtanbau, höheren Produktionskosten bei der Zwei­frucht­nutzung nicht durch entsprechend höhere Trocken­masseerträge kompensiert. Mit Zusatzbewässerung hingegen erzielte das Zweifruchtsystem Roggen-Mais an zwei von drei Versuchsstandorten höhere Deckungsbeiträge als der Hauptfruchtanbau von Mais.    Double-crop (DC) systems are receiving serious consideration as cropping alternative for agricultural biomass production in Germany. In this study the productivity and economics of DC and sole-crop (SC) systems were compared from 2007 to 2009 at three climatically diverse sites of Germany. The warm season crops maize (Zea mays L.), forage sorghum [Sorghum bicolor (L.) Moench] and sorghum-sudangrass [S. bicolor (L.) Moench × S. sudanense (Piper) Stapf] were either grown as sole crops or as second crop following winter rye (Secale cereale L.). The winter rye first crop was harvested premature at early-to-mid May (early) or early June (late). While the winter rye was grown under rainfed conditions, maize, forage sorghum, and sorghum-sudangrass were grown with or without irrigation. Winter rye produced an aboveground dry matter yield (DMY) of 5.2 t ha–1 at early harvest and 9.0 t ha–1 at late harvest. The highest yielding DC system (rye-maize) out-yielded the most productive SC system (maize) by 3.6 t ha–1 (23%) under rainfed conditions and by 5.2 t ha–1 (24%) with irrigation. Irrigation increased DMY of sole crops by 5.3 t ha–1 (37%), of early sown second crops by 5.6 t ha–1 (43%), and of late sown second crops by 6.8 t ha–1 (77%). Under rainfed conditions, the higher DMY of the DC as compared with the SC systems did not compensate the higher production costs. With irrigation, however, the rye-maize DC achieved higher contribution margins than SC maize at two of the three experimental sites.   &nbsp

Energiepflanzenanbau – Wirkungen auf Humusbilanz und Stickstoffhaushalt

Bei der Bewertung der Folgewirkungen des Energiepflanzenanbaus auf Boden und Umwelt ist zwischen den Effekten zu unterscheiden, die von Änderungen in der Landnutzung allgemein bzw. von speziellen Verfahren des Anbaus von Energiepflanzen hervorgerufen werden. Nur die systemimmanenten Effekte des Energiepflanzenanbaus können durch die Verfahrensgestaltung des Selben beeinflusst oder gesteuert werden. Ein wesentliches Element welches den Energiepflanzenanbau vom Anbau traditioneller Marktfrüchte unterscheidet, ist die Rückführung von Gärresten. In diesem Artikel wird daher die Wirkung des Anbaus von Energiepflanzen und die Rückführung von Gärresten auf die Umweltindikatoren Humusbilanz und Stickstoffhaushalt näher untersucht werden. Die Humusbilanzen typischer Energiepflanzenfruchtfolgen sind ohne Ausbringung von Gärresten negativ. Mit Ausbringung von Gärresten sind ausgeglichene Humusbilanzen möglich. Dabei besteht für die Humifizierungs-Faktoren von Gärresten noch Forschungsbedarf. Mit Gärresten kann der Nährstoffkreislauf von Betrieben stärker geschlossen werden. Auf Grund des hohen Mineraldüngeräquivalents kann Mineraldünger gut substituiert werden. Für die Nährstoffe Phosphor, Kalium und Magnesium sind auf dem Nutzungsweg Erntegut–Biogasanlage–Gärrest–Boden keine Verluste zu berücksichtigen. Bei Stickstoff sind nach Berücksichtigung von Verlusten etwa 50 % des Stickstoffs aus dem Erntegut im Boden mineraldüngeräquivalent zur Verfügung

Antimicrobial Use in Pediatric Oncology and Hematology: Protocol for a Multicenter Point-Prevalence Study With Qualitative Expert Panel Assessment

Background: Because infections are a major driver of morbidity and mortality in children with hematologic or oncologic diseases, antimicrobials are frequently prescribed in pediatric oncology practice. However, excess or inappropriate use of antimicrobials is directly linked to the emergence of antimicrobial resistance. Although point-prevalence studies have examined the extent of antimicrobial use, a comprehensive qualitative evaluation of individual antimicrobial prescriptions remains lacking. Objective: The aim of this study is to identify appropriate versus inappropriate antimicrobial use among pediatric cancer patients in a point-prevalence study, followed by an expert panel adjudication process and a subsequent report of these findings to participating centers. This study also aims to improve the quality of patient care by informing centers about discrepancies between internal standards of care and national guidelines. Methods: Our point-prevalence study is performed at pediatric cancer centers in Germany and Austria. All patients under 18 years old who are hospitalized at the time of the study are included. As a supplement to the point-prevalence study, an expert panel is qualitatively assessing each of the antimicrobial prescriptions at the participating centers to review local guidelines and compare them with national guidelines. Results: As of December 2021, the point-prevalence survey has been conducted at 30 sites and expert panel adjudication for qualitative assessment of each antimicrobial use is ongoing. Results of the study are expected in 2022. Conclusions: This is the first point-prevalence study conducted among pediatric cancer centers with an integrated, multistep, qualitative approach that assesses each antimicrobial prescription. The results of this study will inform possible interventions for internal guidelines and antimicrobial stewardship programs implemented at pediatric cancer centers. In addition, local guidelines will be compared with national guidelines. Furthermore, this study will contribute to the overall integration of antimicrobial stewardship principles and initiatives in pediatric oncology and hematology, thereby improving safety and quality of care for children and adolescents with cancer and blood disorders

Cross-sectional seroprevalence surveys of SARS-CoV-2 antibodies in children in Germany, June 2020 to May 2021

The rate of SARS-CoV-2 infections in children remains unclear due to many asymptomatic cases. We present a study of cross-sectional seroprevalence surveys of anti-SARS-CoV-2 IgG in 10,358 children recruited in paediatric hospitals across Germany from June 2020 to May 2021. Seropositivity increased from 2.0% (95% CI 1.6, 2.5) to 10.8% (95% CI 8.7, 12.9) in March 2021 with little change up to May 2021. Rates increased by migrant background (2.8%, 4.4% and 7.8% for no, one and two parents born outside Germany). Children under three were initially 3.6 (95% CI 2.3, 5.7) times more likely to be seropositive with levels equalising later. The ratio of seropositive cases per recalled infection decreased from 8.6 to 2.8. Since seropositivity exceeds the rate of recalled infections considerably, serologic testing may provide a more valid estimate of infections, which is required to assess both the spread and the risk for severe outcomes of SARS-CoV-2 infections

Antimicrobial use in pediatric oncology and hematology in Germany and Austria, 2020/2021: a cross-sectional, multi-center point-prevalence study with a multi-step qualitative adjudication process

Background Due to the high risk of severe infection among pediatric hematology and oncology patients, antimicrobial use is particularly high. With our study, we quantitatively and qualitatively evaluated, based on institutional standards and national guidelines, antimicrobial usage by employing a point-prevalence survey with a multi-step, expert panel approach. We analyzed reasons for inappropriate antimicrobial usage. Methods This cross-sectional study was conducted at 30 pediatric hematology and oncology centers in 2020 and 2021. Centers affiliated to the German Society for Pediatric Oncology and Hematology were invited to join, and an existing institutional standard was a prerequisite to participate. We included hematologic/oncologic inpatients under 19 years old, who had a systemic antimicrobial treatment on the day of the point prevalence survey. In addition to a one-day, point-prevalence survey, external experts individually assessed the appropriateness of each therapy. This step was followed by an expert panel adjudication based upon the participating centers’ institutional standards, as well as upon national guidelines. We analyzed antimicrobial prevalence rate, along with the rate of appropriate, inappropriate, and indeterminate antimicrobial therapies with regard to institutional and national guidelines. We compared the results of academic and non-academic centers, and performed a multinomial logistic regression using center- and patient-related data to identify variables that predict inappropriate therapy. Findings At the time of the study, a total of 342 patients were hospitalized at 30 hospitals, of whom 320 were included for the calculation of the antimicrobial prevalence rate. The overall antimicrobial prevalence rate was 44.4% (142/320; range 11.1–78.6%) with a median antimicrobial prevalence rate per center of 44.5% (95% confidence interval [CI] 35.9–49.9). Antimicrobial prevalence rate was significantly higher (p < 0.001) at academic centers (median 50.0%; 95% CI 41.2–55.2) compared to non-academic centers (median 20.0%; 95% CI 11.0–32.4). After expert panel adjudication, 33.8% (48/142) of all therapies were labelled inappropriate based upon institutional standards, with a higher rate (47.9% [68/142]) when national guidelines were taken into consideration. The most frequent reasons for inappropriate therapy were incorrect dosage (26.2% [37/141]) and (de-)escalation/spectrum-related errors (20.6% [29/141]). Multinomial, logistic regression yielded the number of antimicrobial drugs (odds ratio, OR, 3.13, 95% CI 1.76–5.54, p < 0.001), the diagnosis febrile neutropenia (OR 0.18, 95% CI 0.06–0.51, p = 0.0015), and an existing pediatric antimicrobial stewardship program (OR 0.35, 95% CI 0.15–0.84, p = 0.019) as predictors of inappropriate therapy. Our analysis revealed no evidence of a difference between academic and non-academic centers regarding appropriate usage. Interpretation Our study revealed there to be high levels of antimicrobial usage at German and Austrian pediatric oncology and hematology centers with a significant higher number at academic centers. Incorrect dosing was shown to be the most frequent reason for inappropriate usage. Diagnosis of febrile neutropenia and antimicrobial stewardship programs were associated with a lower likelihood of inappropriate therapy. These findings suggest the importance of febrile neutropenia guidelines and guidelines compliance, as well as the need for regular antibiotic stewardship counselling at pediatric oncology and hematology centers. Funding European Society of Clinical Microbiology and Infectious Diseases, Deutsche Gesellschaft für Pädiatrische Infektiologie, Deutsche Gesellschaft für Krankenhaushygiene, Stiftung Kreissparkasse Saarbrücken

Oral acantholytic squamous cell carcinoma shares clinical and histological features with angiosarcoma

<p>Abstract</p> <p>Background</p> <p>acantholytic squamous cell carcinomas (ASCC) and intraoral angiosarcoma share similar histopathological features. Aim of this study was to find marker for a clear distinction.</p> <p>Methods</p> <p>Four oral acantholytic squamous cell carcinomas and one intraoral angiosarcoma are used to compare the eruptive intraoral growth-pattern, age-peak, unfavourable prognosis and slit-like intratumorous spaces in common histological staining as identical clinical and histopathological features. Immunohistochemical staining for pancytokeratin, cytokeratin, collagen type IV, γ2-chain of laminin-5, endothelial differentiation marker CD31 and CD34, F VIII-associated antigen, Ki 67-antigen, β-catenin, E-cadherin, α-smooth-muscle-actin and Fli-1 were done.</p> <p>Results</p> <p>Cytokeratin-immunoreactive cells can be identified in both lesions. The large vascularization of ASCC complicates the interpretation of vascular differential markers being characteristic for angiosarcoma. Loss of cell-cell-adhesion, monitored by loss of E-cadherin and β-catenin membrane-staining, are indetified as reasons for massive expression of invasion-factor ln-5 in ASCC and considered responsible for unfavourable prognosis of ASCC. Expression of Fli-1 in angiosarcoma and cellular immunoreaction for ln-5 in ASCC are worked out as distinguishing features of both entities.</p> <p>Conclusion</p> <p>Fli-1 in angiosarcoma and ln-5 in ASCC are distinguishing features.</p

Eddy Study to Understand Physical-Chemical-Biological Coupling and the Biological Carbon Pump as a Function of Eddy Type off West Africa, Cruise No. M160, 23.11.2019 - 20.12.2019, Mindelo (Cabo Verde) - Mindelo (Cabo Verde)

Cruise M160 is part of concerted MOSES/REEBUS Eddy Study featuring three major research expeditions (M156, M160, MSM104). It aims to develop both a qualitative and quantitative understanding of the role of physical-chemical-biological coupling in eddies for the biological pump. The study is part of the MOSES “Ocean Eddies” event chain, which follows three major hypotheses to be addressed by the MOSES/REEBUS field campaigns: (1) Mesoscale and sub-mesoscale eddies play an important role in transferring energy along the energy cascade from the large-scale circulation to dissipation at the molecular level. (2) Mesoscale and sub-mesoscale eddies are important drivers in determining onset, magnitude and characteristics of biological productivity in the ocean and contribute significantly to global primary production and particle export and transfer to the deep ocean. (3) Mesoscale and sub-mesoscale eddies are important for shaping extreme biogeochemical environments (e.g., pH, oxygen) in the oceans, thus acting as a source/sink function for greenhouse gases. In contrast to the other two legs, MOSES Eddy Study II during M160 did not include any benthic work but focused entirely on the pelagic dynamics within eddies. It accomplished a multi-disciplinary, multi-parameter and multi-platform study of two discrete cyclonic eddies in an unprecedented complexity. The pre-cruise search for discrete eddies suitable for detailed study during M160 had already started a few months prior to the cruise. Remote sensing data products (sea surface height, sea surface temperature, ocean color/chlorophyll a) were used in combination with eddy detection algorithms and numerical modelling to identify and track eddies in the entire eddy field off West Africa. In addition, 2 gliders and 1 waveglider had been set out from Mindelo/Cabo Verde for pre-cruise mapping of the potential working area north of the Cabo Verdean archipelago. At the start of M160, a few suitable eddies – mostly of cyclonic type – had been identified, some of which were outside the safe operation range of the motorglider plane. As technical problems delayed the flight operations, the first eddy (center at 14.5°N/25°W) for detailed study was chosen to the southwest of the island of Fogo. It was decided to carry out a first hydrographic survey there followed by the deployment of a suite of instruments (gliders, waveglider, floats, drifter short-term mooring). Such instrumented, we left this first eddy and transited – via a strong anticyclonic feature southwest of the island of Santiago – to the region northeast of the island of Sal, i.e. in the working range of the glider plane. During the transit, a full suite of underway measurements as well as CTD/RO section along 22°W (16°-18.5°N) were carried in search for sub-surface expressions of anticyclonic eddy features. In the northeast, we had identified the second strong cyclonic eddy (center at 18°N/22.5°W) which was chosen for detailed study starting with a complete hydrographic survey (ADCP, CTD/RO, other routine station work). After completion of the mesoscale work program, we identified a strong frontal region at the southwestern rim of the cyclonic eddy, which was chosen for the first sub-mesoscale study with aerial observation component. There, the first dye release experiment was carried out which consisted of the dye release itself followed by an intense multi-platforms study of the vertical and horizontal spreading of the initial dye streak. This work was METEOR-Berichte, Cruise M160, Mindelo – Mindelo, 23.11.2019 4 – 20.12.2019 supported and partly guided by aerial observation of the research motorglider Stemme, which was still somewhat compromised by technical issues and meteorological conditions (high cloud cover, Saharan dust event). Nevertheless, this first dye release experiment was successful and showed rapid movement of the dynamic meandering front. After completion of work on this second eddy and execution of a focused sampling program at the Cape Verde Ocean Observation, RV METEOR returned to the first eddy for continuation of the work started there in the beginning of the cruise. This was accompanied by a relocation of the airbase of Stemme from the international airport of Sal to the domestic airport of Fogo. The further execution of the eddy study at this first eddy, which again included a complete hydrographic survey followed by a mesoscale eddy study with dye release, was therefore possible with aerial observations providing important guidance for work on RV METEOR. Overall, M160 accomplished an extremely intense and complex work program with 212 instrument deployments during station work, 137 h of observation with towed instruments and a wide range of underway measurements throughout the cruise. Up to about 30 individually tracked platforms (Seadrones, glider, wavegliders, drifters, floats) were in the water at the same time providing unprecedented and orchestrated observation capabilities in an eddy. All planned work components were achieved and all working groups acquired the expected numbers of instrument deployments and sampling opportunities

Role of mprF1 and mprF2 in the Pathogenicity of Enterococcus faecalis

Aujourd hui, Enterococcus faecalis est considéré comme l un des plus importants agents pathogènes causant des maladies nosocomiales. En raison de sa résistance innée et acquise aux antibiotiques, l identification de nouvelles cibles pour le traitement de cette bactérie est une grande priorité. Le facteur Multiple Peptide Résistance (MprF), qui a été décrit en premier chez Staphylococcus aureus, modifie le phosphatidylglycérol avec de la lysine et réduit ainsi la charge négative de l enveloppe cellulaire. Ceci a comme conséquence d augmenter la résistance aux peptides antimicrobiens cationiques (PAC). Deux gènes paralogues putatifs (mprF1 et mprF2) ont été identifiés chez E. faecalis par recherche BLAST en utilisant le gène décrit chez S. aureus. Une caractérisation de ces deux gènes d E. faecalis ainsi que des mécanismes conduisant à une résistance aux PAC, pourrait aider à développer des nouvelles stratégies thérapeutiques contre ce pathogène. Deux mutants de délétion et un double mutant ont été construits par recombinaison homologue chez E. faecalis. L analyse des phospholipides des membranes cytoplasmiques des deux mutants mprF1 et mprF2 par chromatographie sur couche mince a montré que seule l inactivation de mprF2 inhibe la synthèse de trois amino-phosphatidlyglycérol distincts (comme la Lysine-PG, l Alanine-PG et l Arginine-PG). De plus, le mutant mprF2 est également plus sensible aux PAC que la souche sauvage. La capacité de formation d un biofilm est généralement considérée comme un facteur important de virulence, ce qui est également le cas pour les entérocoques. Le mutant mprF2 montre une capacité accrue dans ce phénomène. Ceci semble être du à une augmentation de la concentration d ADN extracellulaire dans le biofilm formé par ce mutant. Curieusement, cette augmentation est indépendante d une autolyse. Le mutant mprF2 est également plus résistant à l opsonophagocytose. Cependant, le gène mprF2 ne joue aucun rôle dans les bactériémies de souris et les endocardites de rats.En revanche, aucun phénotype n a été trouvé pour un mutant mprF1 jusqu à présent. Cette mutation ne modifie ni la synthèse de l aminoacyl-PG en condition de laboratoire ni la résistance aux PAC et à l opsonophagocytose. Par conséquent, il semble que mprF2 soit le seul gène mprF fonctionnel chez E. faecalis. Néanmoins, contrairement à d autres bactéries, mprF2 ne semble pas être un facteur de virulence majeur pour cette espèce.Enterococcus faecalis is regarded nowadays as one of the most important nosocomial pathogens. Due to its innate and acquired resistance to antibiotics, identification of new targets for antimicrobial treatment of E. faecalis is a high priority. The multiple peptides resistance factor (MprF), which was first described in Staphylococcus aureus, modifies phosphatidylglycerol with lysine and reduces the negative charge of the membrane, thus increasing resistance to cationic antimicrobial peptides (CAMPs). Two putative mprF paralogs (mprF1 and mprF2) were identified in E. faecalis by Blast search using the well-described S. aureus gene as a lead. A better understanding of these two genes and mechanisms leads to enterococcal resistance to CAMPs might help designing therapeutic strategies against this bacteria. Two single deletion mutants and double mutant in E. faecalis were created by homologues recombination. Analysis of cell membrane phospholipids from both mutants by thin-layer chromatography showed that inactivation of mprF2 abolished the synthesis of three distinct amino-phosphatidylglycerol (mostly likely Lysin-PG, Alanine-PG and Argine-PG). The CAMPs testing assay demonstrated that the deletion mutant of mprF2 was more susceptible to CAMPs than the wild type. Biofilm formation is usually regarded as a virulence factor which provides an important way for enterococci to cause infections. Inactivation of mprF2 led to increase the biofilm formation which we showed that it was due to the accumulation of eDNA in the biofilm, but the release of eDNA is independent from autolysis. The mprF2 mutant was resistance to killing by opsonophagocytosis more than wild type. However, the mprF2 gene plays no role in bacteremia in mice and rat endocarditis. Our results showed that non polar effect mprF1 mutant does not affect in the synthesis of aminoacyl-PG in the laboratory condition. It also has no effect on susceptible to CAMPs, opsonic killing and autolysis. Therefore, it seems that mprF2 is the only functional mprF gene in E. faecalis in the laboratory condition. Unlike mprF found in other bacteria, mprF does not seem to be a major virulence factor in enterococci.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF