Production of vineomycin A1 and chaetoglobosin A by Streptomyces sp. PAL114

An actinobacteria strain PAL114, isolated from a Saharan soil in Algeria, produces bioactive compounds. Morphological and chemical studies indicated that this strain belongs to the genus Streptomyces. Analysis of the 16S rRNA gene sequence showed a similarity level of 99.8 % with S. griseoflavus LMG 19344T, the most closely related species. Two bioactive compounds, named P44 and P40, were extracted by dichloromethane from the cell-free supernatant broth and were purified by HPLC. Minimum inhibitory concentrations (MIC) of the compounds were determined against pathogenic and toxigenic microorganisms, most of which are multiresistant to antibiotics. The P40 fraction showed a strong activity especially against Candida albicans, Bacillus subtilis, and Staphylococcus aureus and has lower MIC values than those of P44 against most microorganisms tested. Chemical structures of compounds were determined based on spectroscopic and spectrometric analyses (UV-visible, mass, 1H, and 13C NMR spectra). The compounds P44 and P40 were identified as vineomycin A1 and chaetoglobosin A, respectively. Vineomycin A1 is known to be produced by some Streptomyces species. However, chaetoglobosin A is known to be produced only by fungi belonging to the genera Chaetomium, Penicillium, and Calonectria. This is the first time that chaetoglobosin A, known for its antimicrobial, anticancer, and cytotoxic effects, is reported in prokaryotes

Antimicrobial activities of novel bipyridine compounds produced by a new strain of Saccharothrix isolated from Saharan soil

The actinobacterium strain ABH26 closely related to Saccharothrix xinjiangensis, isolated from an Algerian Saharan soil sample, exhibited highly antagonist activity against Gram-positive bacteria, yeasts and filamentous fungi. Its ability to produce antimicrobial compounds was investigated using several solid culture media. The highest antimicrobial activity was obtained on Bennett medium. The antibiotics secreted by strain ABH26 on Bennett medium were extracted by methanol and purified by reverse-phase HPLC using a C18 column. The chemical structures of the compounds were determined after spectroscopic (1H NMR, 13C NMR, 1H-1H COSY and 1H-13C HMBC spectra), and spectrometric (mass spectrum) analyses. Two new cyanogriside antibiotics named cyanogriside I (1) and cyanogriside J (2), were characterized along with three known caerulomycins, caerulomycin A (3), caerulomycin F (4) and caerulomycinonitrile (5). This is the first report of cyanogrisides and caerulomycins production by a member of the Saccharothrix genus. The minimum inhibitory concentrations (MIC) of these antibiotics were determined against pathogenic microorganisms

Activity of 2,4-Di-tert-butylphenol produced by a strain of Streptomyces mutabilis isolated from a Saharan soil against Candida albicans and other pathogenic fungi

In a search for new antifungal antibiotics active against Candida albicans and others pathogenic fungi, a strain of actinobacteria, designated G61, was isolated from a Saharan soil and tested for its activity against these microorganisms. The analysis of its 16S rDNA sequence showed a similarity level of 100% with Streptomyces mutabilis NBRC 12800T. The highest anticandidal activities produced by the strain G61 were obtained on Bennett medium in the fourth day of incubation. The active product, extracted by n-butanol, contained one bioactive spot detected on thin layer chromatography plates. It was purified by HPLC and its chemical structure was determined by spectroscopic analyses as 2,4-Di-tert-butylphenol. The minimum inhibitory concentrations (MIC) of this product against several strains of pathogenic microorganisms are interesting

Streptomyces sp. AT37 isolated from a Saharan soil produces a furanone derivative active against multidrug-resistant Staphylococcus aureus

A novel actinobacterium strain, named AT37, showed a strong activity against some multidrug-resistant Staphylococcus aureus, including methicillin-resistant S. aureus MRSA ATCC 43300, other clinical isolates of MRSA and vancomycin resistant S. aureus VRSA S1. The strain AT37 was isolated from a Saharan soil by a dilution agar plating method using chitin-vitamin agar medium supplemented with rifampicin. The morphological and chemical studies indicated that this strain belonged to the genus Streptomyces. Its 16S rRNA gene sequence was determined and a database search indicated that it was closely associated with the type strain of Streptomyces novaecaesareae NBRC 13368T with 99.6% of similarity. However, the comparison of the morphological and the physiological characteristics of the strain with those of the nearest species showed significant differences. The strain AT37 secreted the antibiotic optimally during mid-stationary phase of growth. One active compound (AT37-1) was extracted from the culture broth with dichloromethane, separated on silica gel plates and purified by HPLC. Based on spectroscopic analysis of UV-Visible, infrared, and 1H and 13C NMR spectra and spectrometric analysis, the chemical structure of the compound AT37-1 was identified as 5-[(5E,7E,11E)-2,10-dihydroxy-9,11-dimethyl-5,7,11-tridecatrien-1-yl]-2-hydroxy-2-(1-hydroxyethyl)-4-methyl-3(2H)-furanone. Minimum inhibitory concentrations and minimum biofilm inhibitory concentration (MBIC50) of this compound showed significant activity against multidrug-resistant S. aureus with 15-30 and 10-15 μg/mL, respectively

Oligomycins A and E, major bioactive secondary metabolites produced by Streptomyces sp. strain HG29 isolated from a Saharan soil

An actinobacterial strain, HG29, with potent activity against pathogenic, toxigenic and phytopathogenic fungi was isolated from a Saharan soil sample of Algeria. On the basis of morphological and chemotaxonomic characteristics, the strain was classified in the genus Streptomyces. Analysis of the 16S rRNA gene sequence showed a similarity level of 99.3% with Streptomyces gancidicus NBRC 15412T. The comparison of its cultural and physiological characteristics with this species revealed significant differences. Moreover, the phylogenetic tree showed that strain HG29 forms a distinct phyletic line within the genus Streptomyces. Production of antifungal activity was investigated by following kinetics in shake broth. The highest antifungal activity was obtained after five days of fermentation, and in the dichloromethane extract. Two active compounds, NK1 and NK2, were purified by HPLC using a C18 column. Their chemical structures were identified through nuclear magnetic resonance experiments and mass spectrometry as oligomycins E and A, respectively, which have not been reported to be produced by S. gancidicus. The two bioactive compounds exhibited significant antifungal activity in vitro, showing minimal inhibitory concentrations (MICs) values between 2 and 75μg/mL

A novel hydroxamic acid-containing antibiotic produced by a Saharan soil-living Streptomyces strain

During screening for potentially antimicrobial actinobacteria, a highly antagonistic strain, designated WAB9, was isolated from a Saharan soil of Algeria. A polyphasic approach characterized the strain taxonomically as a member of the genus Streptomyces. The strain WAB9 exhibited a broad spectrum of antimicrobial activity toward various multidrug‐resistant micro‐organisms. A PCR‐based assay of genomic potential for producing bioactive metabolites revealed the presence of PKS‐II gene. After 6 days of strain fermentation, one bioactive compound was extracted from the remaining aqueous phase and then purified by HPLC. The chemical structure of the compound was determined by spectroscopic (UV–visible, and 1H and 13C NMR) and spectrometric analysis. The compound was identified to be 2‐amino‐N‐(2‐amino‐3‐phenylpropanoyl)‐N‐hydroxy‐3‐phenylpropanamide, a novel hydroxamic acid‐containing molecule. The pure molecule showed appreciable minimum inhibitory concentration values against a selection of drug‐resistant bacteria, filamentous fungi and yeasts

Saccharothrix sp. PAL54, a new chloramphenicol-producing strain isolated from a Saharan soil

An actinomycete strain designated PAL54, producing an antibacterial substance, was isolated from a Saharan soil in Ghardaïa, Algeria. Morphological and chemical studies indicated that this strain belonged to the genus Saccharothrix. Analysis of the 16S rDNA sequence showed a similarity level ranging between 96.9 and 99.2% within Saccharothrix species, with S. longispora DSM 43749T, the most closely related. DNA–DNA hybridization confirmed that strain PAL54 belonged to Saccharothrix longispora. It showed very strong activity against pathogenic Gram-positive and Gram-negative bacteria responsible for nosocomial infections and resistant to multiple antibiotics. Strain PAL54 secreted the antibiotic optimally during mid-stationary and decline phases of growth. One antibacterial compound was isolated from the culture broth and purified by HPLC. The active compound was elucidated by uv-visible and NMR spectroscopy and by mass spectrometry. The results showed that this compound was a D(-)-threo chloramphenicol. This is the first report of chloramphenicol production by a Saccharothrix species

Measuring the availability of human resources for health and its relationship to universal health coverage for 204 countries and territories from 1990 to 2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: Human resources for health (HRH) include a range of occupations that aim to promote or improve human health. The UN Sustainable Development Goals (SDGs) and the WHO Health Workforce 2030 strategy have drawn attention to the importance of HRH for achieving policy priorities such as universal health coverage (UHC). Although previous research has found substantial global disparities in HRH, the absence of comparable cross-national estimates of existing workforces has hindered efforts to quantify workforce requirements to meet health system goals. We aimed to use comparable and standardised data sources to estimate HRH densities globally, and to examine the relationship between a subset of HRH cadres and UHC effective coverage performance. Methods: Through the International Labour Organization and Global Health Data Exchange databases, we identified 1404 country-years of data from labour force surveys and 69 country-years of census data, with detailed microdata on health-related employment. From the WHO National Health Workforce Accounts, we identified 2950 country-years of data. We mapped data from all occupational coding systems to the International Standard Classification of Occupations 1988 (ISCO-88), allowing for standardised estimation of densities for 16 categories of health workers across the full time series. Using data from 1990 to 2019 for 196 of 204 countries and territories, covering seven Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) super-regions and 21 regions, we applied spatiotemporal Gaussian process regression (ST-GPR) to model HRH densities from 1990 to 2019 for all countries and territories. We used stochastic frontier meta-regression to model the relationship between the UHC effective coverage index and densities for the four categories of health workers enumerated in SDG indicator 3.c.1 pertaining to HRH: physicians, nurses and midwives, dentistry personnel, and pharmaceutical personnel. We identified minimum workforce density thresholds required to meet a specified target of 80 out of 100 on the UHC effective coverage index, and quantified national shortages with respect to those minimum thresholds. Findings: We estimated that, in 2019, the world had 104·0 million (95% uncertainty interval 83·5–128·0) health workers, including 12·8 million (9·7–16·6) physicians, 29·8 million (23·3–37·7) nurses and midwives, 4·6 million (3·6–6·0) dentistry personnel, and 5·2 million (4·0–6·7) pharmaceutical personnel. We calculated a global physician density of 16·7 (12·6–21·6) per 10 000 population, and a nurse and midwife density of 38·6 (30·1–48·8) per 10 000 population. We found the GBD super-regions of sub-Saharan Africa, south Asia, and north Africa and the Middle East had the lowest HRH densities. To reach 80 out of 100 on the UHC effective coverage index, we estimated that, per 10 000 population, at least 20·7 physicians, 70·6 nurses and midwives, 8·2 dentistry personnel, and 9·4 pharmaceutical personnel would be needed. In total, the 2019 national health workforces fell short of these minimum thresholds by 6·4 million physicians, 30·6 million nurses and midwives, 3·3 million dentistry personnel, and 2·9 million pharmaceutical personnel. Interpretation: Considerable expansion of the world's health workforce is needed to achieve high levels of UHC effective coverage. The largest shortages are in low-income settings, highlighting the need for increased financing and coordination to train, employ, and retain human resources in the health sector. Actual HRH shortages might be larger than estimated because minimum thresholds for each cadre of health workers are benchmarked on health systems that most efficiently translate human resources into UHC attainment

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations