31 research outputs found
Plant growth promoting activities of Pseudomonas sp. and Enterobacter sp. isolated from the rhizosphere of Vachellia gummifera in Morocco
The Moroccan endemic Vachellia gummifera grows wild under extreme desert conditions. This plant could be used as an alternative fodder for goats, and camels, in order to protect the Argan forests against overgrazing in Central and Southwestern Moroccan semiarid areas. With the aim to improve the V. gummifera population's density in semiarid areas, we proposed its inoculation with performing plant growth-promoting bacteria. Hence, 500 bacteria were isolated from the plant rhizosphere. From these, 291 isolates were retained for plant growth-promoting (PGP) activities assessment. A total of 44 isolates showed the best phosphates solubilization potential, as well as siderophore and auxin production. The combination of REP-PCR (repetitive extragenic palindromic-polymerase chain reaction) fingerprinting, PGP activities, and phenotypic properties, allowed the selection of three strains for the inoculation experiments. The three selected strains' 16S rRNA sequencing showed that they are members of the Enterobacter and Pseudomonas genera. The inoculation with three strains had diverse effects on V. gummifera growth parameters. All single and combined inoculations improved the plant shoot weight by more than 200%, and the root length by up to 139%, while some combinations further improved protein and chlorophyll content, thereby improving the plant's forage value. The three selected strains constitute an effective inoculum for use in the arid and semiarid zones of southern Morocco.The authors want to thank all the persons who contributed to the achievement of this work. This work was funded by the Hassan II Academy of Science and Technology (AH2ST), in Morocco. B.M. received a grant from the AH2ST. She received also the excellency fellowship Khadija Baddouri in life sciences, from the Horizons foundation, Franc
Different species of Bradyrhizobium from symbiovars genistearum and retamae nodulate the endemic Retama dasycarpa in the High Atlas Mountains
Retama dasycarpa is an endemic Retama species native to the cold semi-arid bioclimates of the High Atlas Mountains in Morocco. In this work, we analyzed the diversity of the microsymbionts nodulating this plant and their different phenotypic and symbiotic characteristics. Phylogenetic analysis of the 16S rRNA gene revealed that the tested isolates clustered in the Bradyrhizobium genus. Multilocus sequence analyses of four housekeeping genes (recA, gyrB, glnII and atpD) for 12 selected strains grouped them into four clusters close to B. lupini USDA 3051, B. frederickii CNPSo 3446, B. valentinum LmjM3 and B. retamae Ro19. The individual phylogenies of these core genes and the symbiotic genes nodC, nodA and nifH were congruent. These isolates showed a broad host range, being able to nodulate different legume hosts, such as R. sphaerocarpa, R. monosperma, Lupinus luteus, Cytisus grandiflorus and Chamaecytisus albidus, but not Phaseolus vulgaris or Glycine max. They all had a similar metabolic capacity, using the majority of the carbohydrates and amino acids tested as sole sources of carbon and nitrogen. Furthermore, out of the 12 selected strains, some displayed plant growth-promoting features, with six of them solubilizing phosphate and three of them producing siderophores. The present work provides, for the first time, a detailed description about the microsymbionts associated with the endemic legume R. dasycarpa.This work was supported by the Ministry of Higher Education and Innovation. Dr Mouad Lamrabet was granted a fellowship from the PPR2-BIOMIVER project. The authors want to thank all the
people who contributed to this work
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
A Recombinant Antigen-Based ELISA for the Simultaneous Differential Serodiagnosis of Mycoplasma gallisepticum, Mycoplasma synoviae, and Mycoplasma meleagridis Infections
International audienceWe have previously identified species-specific DNA fragments, referred to as MS2/28 and Mm14, of Mycoplasma synoviae and Mycoplasma meleagridis, respectively. In the present study, we extended our analysis of the MS2/28 fragment that was found to encode a species-specific antigenic site, and we demonstrated the specificity of the Mycoplasma gallisepticum hemagglutinin protein encoded by pMGA1.2 (a member of the vlhA gene family). Then, we combined the Escherichia coli-expressed products of MS2/28, Mm14, and pMGA1.2, to develop a recombinant antigen-based enzyme-linked immunosorbent assay (recELISA), for the simultaneous and specific detection of antibodies to the three aforementioned major avian mycoplasma species. For comparative purposes, a novel in-house crude antigen capture ELISA (capELISA) was developed in parallel. In the latter protocol, the microtiter wells were enriched in species-specific antigens by capturing sonicated crude antigens on coated rabbit polyclonal antibodies that had been extensively adsorbed with the whole antigen of the heterologous species. With regard to rapid serum agglutination, both ELISA tests were highly specific, and they showed a significant correlation when field sera from naturally infected birds were tested. recELISA proved to be highly specific because absorbance values, with the heterologous species, were significantly lower (P<0.001) than those obtained with capELISA. Given its cost-effectiveness and simplicity, the recombinant antigen-based ELISA seems to represent a valid tool for the specific screening of the three major avian mycoplasma species. recELISA will be particularly useful with regard to trade control because a large number of samples from various fields could be rapidly processed
Duplex PCR To Differentiate between Mycoplasma synoviae and Mycoplasma gallisepticum on the Basis of Conserved Species-Specific Sequences of Their Hemagglutinin Genes
We developed a duplex PCR assay targeting the hemagglutinin multigene families, vlhA and pMGA, of Mycoplasma synoviae and Mycoplasma gallisepticum, respectively. The assay proved to be specific and sensitive enough to justify its use for the simultaneous detection of the two major avian mycoplasma species from field isolates
Molecular cloning of a Mycoplasma meleagridis-specific antigenic domain endowed with a serodiagnostic potential
International audienceA recombinant phage library harbouring Mycoplasma meleagridis (MM) genomic DNA fragments was generated in the bacteriophage lambda gt11 expression vector. The library was screened for expression of MM specific antigens with a polyclonal antiserum that had been preadsorbed with antigens of the most common unrelated avian mycoplasma species. A 49-aminoacid antigenic domain unique to MM was isolated, expressed in Escherichia coli, and its serodiagnostic potential was demonstrated. An antiserum raised against this MM-specific antigenic domain recognized a cluster of seven membrane-associated MM proteins with molecular masses ranging from 34 to 75 kDa. Overall, this study resulted in the identification of a potent serodiagnostic tool and revealed the complex antigenic nature of MM. (c) 2006 Elsevier B.V. All rights reserved
Identification of the symbiovar maamori in Mesorhizobium isolated from nodules of Ononis repens in the Maamora forest (Morocco)
Ononis repens is a legume of the Fabaceae family with great ecological and medicinal importance that grows wild in the Maamora cork oak forest (Rabat, Morocco). The aim of this work was to analyze the diversity, phylogeny, and plant growth-promoting features of the plant root nodules microsymbionts. Out of twenty nodC-containing rhizobial bacteria, four strains, ORM6, ORM8.1, ORM 13.1, and ORM16, were selected for further molecular and phenotypic analyses. All four strains were able to metabolize a wide range of carbohydrates and amino acids as sole carbon and nitrogen sources, respectively, and grew in the presence of different pH, NaCl, and temperature conditions. They also solubilized inorganic phosphate and produced siderophores, and ORM16 was the only strain to produce indol acetic acid. The rrs gene sequence analysis showed that the four strains are members of the Mesorhizobium genus. The individual and concatenated sequences of the recA, glnII, and gyrB housekeeping genes revealed that the strains ORM6 and ORM 13.1 clustered with M. jarvisii ATCC 33,669 and M. intechii BD68 , with which they share 93.3 and 93.7% similarity, respectively; that the strain ORM8.1 affiliated with a group of which the strain M. shonense AC39a was the closest relative species with 84.3% similarity; and that the strain ORM16 clustered with M. australicum LMG24608, with 80.5% similarity. These results suggest that the four O. repens-isolated strains could belong to three putative new genospecies. All four strains nodulated their original host as well as Astragalus gombiformis and A. armatus, but only the strain ORM16 was able to form nodules on Vachellia gummifera. Analysis of the symbiotic nodC gene phylogenies showed that the strains ORM6, ORM8.1, ORM 13.1, and ORM16 formed a group apart from the known symbiovars in the genus Mesorhizobium, for which the name maamori is proposed.This work was supported by Hassan II Academy of Sciences and Technology, in Morocco. Grant P18-RT-1401 from Junta de AndalucĂa is also acknowledged. The authors want to thank all the persons who contributed to this work