Hasil untuk "Microbiology"

I. R. Kaplan, S. Rittenberg

Joanna Maria Jasińska, Klaudia Michalska, Joanna Tkaczewska et al.

Novel double-layer films based on furcellaran (FUR) and gelatin (GEL) with the addition of <i>Phytolacca americana</i> L. (PA) extract were used as active packaging for African catfish fillets. Films with PA extract have been shown to minimize the catfish spoilage effects, expressed as odor reduction compared to control samples; however, neither the films nor the PA extract exhibited antimicrobial activity against tested groups of microorganisms (fungi, lactic acid bacteria, <i>Enterobacterales</i> and psychrotrops) or specified microorganisms (<i>E. coli</i>, <i>S. aureus</i>, <i>S. cerevisiae</i>). The tested films demonstrated antioxidant activity determined by the DPPH, ABTS, FRAP, CUPRAC and Folin–Ciocâlteu methods. Cytotoxicity analysis showed that the PA extract affected tested cell lines (PNT2—prostate epithelial cells, HepG2—human liver cells, HaCaT—normal human keratinocytes and Nty-hori 3-1) only to a small extent—the calculated IC₅₀ values exceeded the maximal tested concentration of 500 µg/mL.

Jabir Thajudeen, Siddarthan Venkatachalam, Puthiya Veettil Vipindas

ABSTRACT Antibiotic resistance genes (ARGs) pose a significant threat, exacerbated by climate change impacts on polar regions, particularly melting glaciers and permafrost. While ancient antibiotic resistance exists in the environments, the release and dissemination of ARGs remain poorly understood. This study investigated ARG composition and distribution in 43 metagenomes from Arctic and Antarctic glacier forelands. We identified 154 ARGs, predominantly bacitracin resistance, followed by rifamycin, fosfomycin, vancomycin, tetracycline, and beta-lactam resistance genes. Significant correlations were observed between ARGs and mobile genetic elements (MGEs), with 20 ARGs associated with tnpA MGEs. Actinomycetota and Pseudomonadota were the primary ARG-carrying phyla. Metagenome-assembled genomes revealed Mycobacterium sp., Pseudomonas sp., and Tatlockia sp. as major ARG-harboring pathogens in the glacier forelands. Evolutionarily adapted, distinct ancient ARGs were abundant in the polar environments, varying between different geographic regions. The environmental parameters such as pH and total organic carbon significantly influenced the ARG distribution in the Arctic and Antarctic glacier forelands. This study provides crucial baseline data on antimicrobial resistance, highlighting potential risks associated with rapid environmental change in the regions.IMPORTANCEAntibiotic resistance poses a significant global health threat, exacerbated by the release of antibiotic resistance genes from melting glaciers and permafrost due to climate change. This study provides crucial baseline data on the composition and distribution of antibiotic resistance genes in these vulnerable polar environments, which is essential for understanding and mitigating the risks associated with their release. The findings have far-reaching implications for global health security and emphasize the need for further research to address this emerging threat.

A. Tamime, R. Robinson

Joicy Anabel Franco Coffre, Maudlyn O. Etekochay, Malik Olatunde Oduoye

Yuyun Huang, Lili Jia, Fusheng Chen

<i>wetA</i>, one of the conidiation center regulatory genes in many filamentous fungi, plays an important role in promoting asexual spores (conidia) maturation. Our recent research has found that knocking out or overexpressing <i>MrwetA</i> (a homolog of <i>wetA</i>) in <i>Monascus ruber</i> M7 does not affect the development of its asexual spores like other fungi, but both repress the development of its sexual spores (ascospores). However, the mechanism remains unclear. In this study, the function of <i>MrwetA</i> on sexual reproduction and secondary metabolism in <i>M. ruber</i> M7 was confirmed by a complementary experiment. Moreover, the regulatory roles of <i>MrwetA</i> in modulating the expression of genes involved in sexual reproduction, meiosis, and biosynthesis of <i>Monascus</i> pigment and citrinin were analyzed based on the transcriptional data. These results not only contribute to clarifying the regulation of the reproduction and secondary metabolism of <i>Monascus</i> spp., but also to enriching the regulation molecular mechanism of reproduction in filamentous fungi.

Aleksandar Nikolov, Lili Dobreva, Svetla Danova et al.

Many antimicrobial coatings deliver a peak release of antimicrobial agent at an early age, after which they lost antimicrobial activity over time. In the present study a novel geopolymer paints with long term antimicrobial activity were developed based on natural zeolite modified with silver and copper ions. The obtained geopolymer paints were applied by brushing on concrete, ceramic, gypsum paperboard and steel. The coating was characterized by excellent adhesive strength and hiding properties. The long-term antimicrobial effect was evaluated by accelerated aging in carbonation chamber. Microstructural changes were analyzed by powder X-ray diffraction and Fourier transformed infrared spectroscopy. Cytotoxicity, antibacterial, antifungal and virucidal properties were investigated on raw and carbonated geopolymer paints. Geopolymer paints based on modified natural zeolite seems promising antimicrobial coating material that can be implemented in the global fight against the spread of diseases and pathogens.

K. P. Smith, J. Kirby

BACKGROUND Microbiologists are valued for their time-honed skills in image analysis including identification of pathogens and inflammatory context in Gram stains, ova and parasite preparations, blood smears, and histopathological slides. They also must classify colonial growth on a variety of agar plates for triage and workup. Recent advances in image analysis, in particular application of artificial intelligence (AI), have the potential to automate these processes and support more timely and accurate diagnoses. OBJECTIVES To review current artificial intelligence-based image analysis as applied to clinical microbiology and discuss future trends in the field. SOURCES Material sourced for this review included peer-reviewed literature annotated in the PubMed or Google Scholar databases and preprint articles from bioRxiv. Articles describing use of AI for analysis of images used in infectious disease diagnostics were reviewed. CONTENT We describe application of machine learning towards analysis of different types of microbiological image data. Specifically, we outline progress in smear and plate interpretation and potential for AI diagnostic applications in the clinical microbiology laboratory. IMPLICATIONS Combined with automation, we predict that AI algorithms will be used in the future to pre-screen and pre-classify image data, thereby increasing productivity and enabling more accurate diagnoses through collaboration between the AI and microbiologist. Once developed, image-based AI analysis is inexpensive and amenable to local and remote diagnostic use.

H. Frickmann, A. Zautner, A. Moter et al.

P. Parize, E. Muth, C. Richaud et al.

H. Leclerc, D. Mossel, S. Edberg et al.

Samar Tharwat, Dalia Kamal Nassar, Mohammed Kamal Nassar et al.

Abstract Background Herd immunity is necessary to contain the coronavirus disease 2019 (COVID-19) pandemic. Vaccination is the fastest and safest pandemic control strategy. Healthcare workers (HCWs) are essential in providing vaccination information. The aim of this study was to assess intent to be vaccinated against COVID-19 among HCWs in Egypt and to determine the factors that may influence their decision. Methods A questionnaire-based cross-sectional study was conducted among HCWs who care for patients in several hospitals in Delta region, Egypt. The questionnaire included sociodemographic, clinical, and occupational data, intention to receive the COVID-19 vaccine, and beliefs and attitudes towards COVID-19 and its vaccination. Results The study included 455 HCWs with a mean age of 36.55 years (SD = 10.31) and 80% were females. The acceptance rate for the COVID-19 vaccine was 70.5%, while hesitancy and resistancy were both 17.6 and 11.9% respectively. About one-third (33.4%) of the subjects had previously contracted COVID-19. Most participants believed that they had a higher risk of contracting COVID-19 (71.6%). More than 64% believed they were at risk for vaccination side effects. Fear of infection and being at high risk of infection were the main drivers for COVID-19 vaccination, while the major barriers were waiting for additional experience with these new vaccines and having doubts about the vaccines’ efficacy. Conclusions The acceptance of the COVID-19 vaccination among HCWs is very high. This crucial group needs to be the focus of educational initiatives and campaigns designed to increase public awareness of the safety and effectiveness of COVID-19 vaccination.

Tobias Dörr, P. Moynihan, C. Mayer

Department of Microbiology, Weill Institute for Cell and Molecular Biology, Ithaca, NY, United States, Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY, United States, 3 School of Biosciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom, Department of Biology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany

Analy Machado de Oliveira Leite, M. Miguel, R. Peixoto et al.

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19th century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21th century yoghurt. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

B. Gomes, E. T. Pinheiro, Cícero R Gadê-Neto et al.

H. Maeda, C. Fujimoto, Yasuhiro Haruki et al.

V. Loureiro, M. Malfeito-Ferreira

R. Oremland, J. Stolz

E. Madsen

Siheng Wang, Chang Cai, Yingbo Shen et al.

Contezolid is a novel oxazolidinone, which exhibits potent activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and penicillin-resistant Streptococcus pneumoniae (PRSP). In this study, the in vitro activity of contezolid was compared with linezolid (LZD), tigecycline (TGC), teicoplanin (TEC), vancomycin (VA), daptomycin (DAP), and florfenicol (FFC) against MRSA and VRE strains isolated from China. Contezolid revealed considerable activity against MRSA and VRE isolates with MIC90 values of 0.5 and 1.0 μg/mL, respectively. For VRE strains with different resistance genotypes, including vanA- and vanM-type strains, contezolid did not exhibit significantly differential antibacterial activity. Furthermore, the antimicrobial activity of contezolid is similar to or slightly better than that of linezolid against MRSA and VRE strains. Subsequently, the activity of contezolid was tested against strains carrying linezolid resistance genes, including Staphylococcus capitis carrying cfr gene and Enterococcus faecalis carrying optrA gene. The results showed that contezolid exhibited similar antimicrobial efficacy to linezolid against strains with linezolid resistance genes. In general, contezolid may have potential benefits to treat the infections caused by MRSA and VRE pathogens.