8 research outputs found
A consortium of Rhizosphere-Competent actinobacteria exhibiting multiple plant Growth-Promoting traits improves the growth of Avicennia marina in the United Arab Emirates
Gray mangrove (Avicennia marina) is the dominant vegetation distributed along the coast of the United Arab Emirates (UAE). Despite its performance as natural coastal guardians, very little is known about the reforestation projects to increase mangrove cover over the years in the UAE and in the Arabian Gulf. Plant growth-promoting actinobacteria (PGPA) were isolated from the mangrove rhizosphere sediments found in the UAE and were evaluated for their potential to produce plant growth regulators (PGRs) and to enhance mangrove growth under seawater irrigation conditions. In vitro screening identified nine rhizosphere-competent actinobacterial isolates, in a naturally competitive environment, of which Streptomyces coelicoflavus (Sc) showed a high phosphorus solubilizing activity. Moreover, Streptomyces polychromogenes (Sp), Streptomyces bacillaris (Sb), and Streptomyces ferrugineus (Sf) produced auxins, polyamines (PAs), and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, respectively. Although sediment inoculation with single isolates significantly improved the dry biomass of mangrove shoots (43.2–74.0%) and roots (40.8–75.9%), the consortium of isolates (Sc/Sp/Sb/Sf) caused a greater increase in the dry weight of shoots (82.1%) and roots (81.6%) compared with seawater-irrigated plants (control). In our greenhouse experiments, the levels of photosynthetic pigments, in planta auxins, and PAs significantly increased in plant tissues inoculated with Sc/Sp/Sb/Sf; whereas ACC contents were reduced. This was also evident as the maximum velocity of rubisco carboxylation (Vcmax) increased four-fold in plants treated with the mixture of isolates over control. To the best of our knowledge, this is the first study reporting culturable halotolerant, rhizosphere-competent PGPA inhabiting salty and arid ecosystems applied individually or in combination to promote mangrove growth under harsh conditions such as those found in the Arabian coastal areas
Multiple early introductions of SARS-CoV-2 into a global travel hub in the Middle East
International travel played a significant role in the early global spread of SARS-CoV-2. Understanding transmission patterns from different regions of the world will further inform global dynamics of the pandemic. Using data from Dubai in the United Arab Emirates (UAE), a major international travel hub in the Middle East, we establish SARS-CoV-2 full genome sequences from the index and early COVID-19 patients in the UAE. The genome sequences are analysed in the context of virus introductions, chain of transmissions, and possible links to earlier strains from other regions of the world. Phylogenetic analysis showed multiple spatiotemporal introductions of SARS-CoV-2 into the UAE from Asia, Europe, and the Middle East during the early phase of the pandemic. We also provide evidence for early community-based transmission and catalogue new mutations in SARS-CoV-2 strains in the UAE. Our findings contribute to the understanding of the global transmission network of SARS-CoV-2
Growth Promotion of Salicornia bigelovii by Micromonospora chalcea UAE1, an Endophytic 1-Aminocyclopropane-1-Carboxylic Acid Deaminase-Producing Actinobacterial Isolate
Salicornia bigelovii is a promising halophytic crop for saline soils in semi-arid regions. This study was designed to characterize isolates of endophytic actinobacteria from S. bigelovii roots and evaluate the effects associated with plant growth promotion. Twenty-eight endophytic isolates obtained from surface-sterilized roots of S. bigelovii were initially selected based on their production of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase in vitro in a chemically defined medium. Application of Micromonospora chalcea UAE1, possessing the highest ACC deaminase activity, to S. bigelovii seedlings significantly enhanced the plant growth under gnotobiotic and greenhouse conditions. This was clear from the increases in the dry weight and length of both shoot and root, and seed yield compared to the non-ACC deaminase-producing isolate Streptomyces violaceorectus, or control treatment. The growth promotion was also supported by significant increases in the content of photosynthetic pigments and the levels of auxins, but significant decreases in the levels of ACC in planta. Under greenhouse conditions, M. chalcea recovered from inside the inoculated roots in all samplings (up to 12 weeks post inoculation), suggesting that the roots of healthy S. bigelovii are a suitable habitat for the endophytic actinobacterial isolates. Pure cultures of M. chalcea were not capable of producing auxins, gibberellic acid, cytokinins or polyamines in vitro. This indicates that the growth promotion is most likely to be due to the reduction of the endogenous levels of the stress hormone ethylene. Our findings suggest that growth and yields of S. bigelovii can be enhanced by the field application of the endophyte M. chalcea UAE1. This study is the first to report potential endophytic non-streptomycete actinobacteria to promote the growth of halophytic plants in semi-arid zones under greenhouse conditions
Healthcare derived smart watches and mobile phones are contaminated niches to multidrug resistant and highly virulent microbes
Background: As high touch wearable devices, the potential for microbial contamination of smart watches is high. In this study, microbial contamination of smart watches of healthcare workers (HCWs) was assessed and compared to the individual’s mobile phone and hands.
Methods: This study was part of a larger point prevalence survey of microbial contamination of mobile phones of HCWs at the emergency unit of a tertiary care facility. Swabs from smart watches, mobile phones and hands were obtained from four HCWs with dual ownership of these digital devices. Bacterial culture was carried out for all samples and those from smart watches and mobile phones were further assessed using shotgun metagenomic sequencing.
Results: Majority of the participants were females (n/N = 3/4; 75%). Although they all use their digital devices at work and believe that these devices could harbour microbes, cleaning in the preceding 24 hours was reported by one individual. Predominant organisms identified on bacterial culture were multidrug resistant Staphylococcus hominis and Staphylococcus epidermidis. At least one organism identified from the hands was also detected on all mobile phones and two smart watches. Shotgun metagenomics analysis demonstrated greater microbial number and diversity on mobile phones compared to smart watches. All devices had high signatures of Pseudomonas aeruginosa and associated bacteriophages and antibiotic resistance genes. Almost half of the antibiotic resistance genes (n/N = 35/75;46.6%) were present on all devices and majority were related to efflux pumps. Of the 201 virulence factor genes (VFG) identified, majority (n/N = 148/201;73%) were associated with P. aeruginosa with 96% (n/N = 142/148) present on smart watches and mobile phones.
Conclusion: This first report on microbial contamination of smart watches using metagenomics next generation sequencing showed similar pattern of contamination with microbes, VFG and antibiotic resistance genes across digital devices. Further studies on microbial contamination of wearable digital devices are urgently needed
Polyamine-producing actinobacteria enhance biomass production and seed yield in Salicornia bigelovii
Thirty-five actinobacterial isolates obtained from Salicornia bigelovii rhizosphere in the United Arab Emirates were evaluated for their potential to produce polyamines and for their abilities to be rhizosphere-competent. The highly polyamine-producing Actinoplanes deccanensis UAE1 and Streptomyces euryhalinus UAE1 were selected, and their inoculation impacts on S. bigelovii were assessed under greenhouse conditions. Application of any of the two isolates significantly increased the length and dry weight of shoot and root tissues, photosynthetic pigments, and seed yields compared to control plants, suggesting that A. deccanensis and S. euryhalinus can promote S. bigelovii growth. The application of these isolates resulted in significant increases in the levels of endogenous free polyamines and plant growth regulators (auxins, gibberellic acid, and cytokinins), but a concomitant reduction in abscisic acid in S. bigelovii-tested tissues. Specifically, we found that putrescine, spermidine, and spermine produced by S. euryhalinus were the major contributors to plant growth parameters, but to a lesser extent by A. deccanensis. Both A. deccanensis and S. euryhalinus were, however, not capable of producing significant levels of other plant growth regulators in vitro. Plant yield was higher in the presence of S. euryhalinus than with A. deccanensis, suggesting relative superiority of S. euryhalinus as a rhizosphere-competent isolate compared to the nonrhizosphere-competent isolate A. deccanensis. This is the first study reporting the production of polyamines by marine actinobacteria and demonstrating the potential of polyamine-producing actinobacteria to enhance growth of halophytic plants through the increase in the endogenous levels of free polyamines and other plant growth regulators
Coinfections in Patients Hospitalized with COVID-19: A Descriptive Study from the United Arab Emirates
Abiola Senok,1,* Mubarak Alfaresi,2,* Hamda Khansaheb,3 Rania Nassar,1,4 Mahmood Hachim,1 Hanan Al Suwaidi,1 Majed Almansoori,2 Fatma Alqaydi,2 Zuhair Afaneh,2 Aalya Mohamed,2 Shahab Qureshi,2 Ayman Ali,2 Abdulmajeed Alkhajeh,3 Alawi Alsheikh-Ali1,3 1College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates; 2Sheikh Khalifa General Hospital, Umm Al Quwain, United Arab Emirates; 3Dubai Health Authority, Dubai, United Arab Emirates; 4Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff, UK*These authors contributed equally to this workCorrespondence: Abiola SenokCollege of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, PO Box 505055, Dubai, United Arab EmiratesTel +971-4-383-8717Email [email protected]: Microbial coinfections in COVID-19 patients carry a risk of poor outcomes. This study aimed to characterize the clinical and microbiological profiles of coinfections in patients with COVID-19.Methods: A retrospective review of the clinical and laboratory records of COVID-19 patients with laboratory-confirmed infections with bacteria, fungi, and viruses was conducted. Only adult COVID-19 patients hospitalized at participating health-care facilities between February 1 and July 31, 2020 were included. Data were collected from the centralized electronic system of Dubai Health Authority hospitals and Sheikh Khalifa General Hospital Umm Al Quwain.Results: Of 29,802 patients hospitalized with COVID-19, 392 (1.3%) had laboratory-confirmed coinfections. The mean age of patients with coinfections was 49.3± 12.5 years, and a majority were male (n=330 of 392, 84.2%). Mean interval to commencement of empirical antibiotics was 1.2± 3.6) days postadmission, with ceftriaxone, azithromycin, and piperacillin–tazobactam the most commonly used. Median interval between admission and first positive culture (mostly from blood, endotracheal aspirates, and urine specimens) was 15 (IQR 8– 25) days. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli were predominant in first positive cultures, with increased occurrence of Stenotrophomonas maltophilia, methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, Candida auris, and Candida parapsilosis in subsequent cultures. The top three Gram-positive organisms were Staphylococcus epidermidis, Enterococcus faecalis, and Staphylococcus aureus. There was variability in levels of sensitivity to antibiotics and isolates harboring mecA, ESBL, AmpC, and carbapenemase-resistance genes were prevalent. A total of 130 (33.2%) patients died, predominantly those in the intensive-care unit undergoing mechanical ventilation or extracorporeal membrane oxygenation.Conclusion: Despite the low occurrence of coinfections among patients with COVID-19 in our setting, clinical outcomes remained poor. Predominance of Gram-negative pathogens, emergence of Candida species, and prevalence of isolates harboring drug-resistance genes are of concern.Keywords: SARS-CoV2, microbial coinfections, clinical outcomes, Pseudomonas, Candid