Streptomyces netropsis SD-07, the producer of novel polyene macrolide antifungal antibiotics, was isolated from soil. For the investigation of the functions of its biosynthesis genes and regulation mechanisms, a genetic operating system is necessary. In this study, we successfully transferred the plasmid DNA of pSET152 from the methylation deficient donor, Escherichia coli ET12567/pSET152/pUZ8002, to S. netropsis SD-07 by conjugation and evaluated the crucial factors influencing the conjugation frequency. Ca(2+) ions in presence the conjugation media may increase the conjugation frequency by 1000-10 000 times than Ca(2+) ions absence in the same conjugation media, and 10-100 time higher than Mg(2+) ions. Similar results (increasing the conjugation frequency by 10-100 times when media containing 60 mM CaCl2 ) were also obtained from the conjugation between E. coli ET12567 and Streptomyces coelicolor, S. lavendulae, S. venezuelae, despite their conjugation media were different (MS, CM, GS). So, CaCl2 concentration is a crucial factor for increasing the conjugation frequency, and the suitable concentration may probably be 60 mM. In addition, synthetic medium containing a small amount of organic nitrogen source may benefit increasing the conjugation frequency. These findings could be valuable for the development of a practical method for achieving conjugation in other Streptomyces spp.
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http://dx.doi.org/10.1111/1574-6968.12507 | DOI Listing |
Environ Res
January 2025
Chinese Academy of Sciences Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China; Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China. Electronic address:
Both antibiotics and heavy metals exert significant selection pressures on antibiotic-resistance genes (ARGs). This study aimed to investigate the co-selection effects of doxycycline (DC) and cadmium (Cd) on ARGs in constructed wetlands (CWs). The results demonstrated that under antibiotic and heavy metal co-selection pressures, single high concentration DC/Cd or double high, relative abundances of metagenomics assembled genomes all reached 55.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
January 2025
Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Context: The timing of a woman's final menstrual period (FMP) in relation to her age is considered a valuable indicator of overall health, being associated with cardiovascular, bone health, reproductive, and general mortality outcomes.
Objective: This work aimed to evaluate the relationship between hormones and the "time to FMP" when daily hormone trajectories are characterized by their 1) entropy, and 2) deviation from premenopausal/stable cycle patterns (representing a textbook "gold standard"; GS).
Methods: As part of the Study of Women's Health Across the Nation, urinary luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrogen conjugates (E1C), and pregnanediol glucuronide (PDG) were measured daily from a multiracial sample of 549 mid-life women for the duration of one menstrual cycle.
Vaccine
January 2025
Section Pediatric Infectious Diseases, Laboratory of Medical Immunology, Radboud Institute for Molecular Life Sciences, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands.
In this study, we describe S. pneumoniae serotype distribution before and after PCV13 rollout in Tanzania. We serotyped S.
View Article and Find Full Text PDFBMC Infect Dis
January 2025
Division of Animal Biotechnology, Faculty of Veterinary Sciences & Animal Husbandry, SKUAST Kashmir, Shuhama, J&K, 190006, India.
Background: Salmonella infections represent a major global public health concern due to their widespread zoonotic transmission, antimicrobial resistance, and associated morbidity and mortality. This review aimed to summarize the zoonotic nature of Salmonella, the challenges posed by antimicrobial resistance, the global burden of infections, and the need for effective vaccination strategies to mitigate the rising threat of Salmonella.
Methods: A systematic review of literature was conducted using databases such as PubMed, Scopus, Web of Science, and Google Scholar.
J Hazard Mater
January 2025
College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China. Electronic address:
The production scalability and increasing demand for black phosphorus nanosheets (BPNSs) inevitably lead to environmental leakage. Although BPNSs' ecotoxicological effects have been demonstrated, their indirect health risks, such as inducing increased resistance in pathogenic bacteria, are often overlooked. This study explores the influence of BPNSs on the horizontal gene transfer of antibiotic resistance genes (ARGs) facilitated by the RP4 plasmid, which carries multiple resistance genes.
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