A total of 95 Enterococcus faecalis strains isolated from different human clinical sources were investigated for hemagglutinating activities and hemolysin (Hly) production in the presence of erythrocytes from a wide range of species. MRHA (mannose-resistant hemagglutination) activity was found in all clinical strains tested in this study. MRHA of E. faecalis strains isolated from different sources was most frequently observed with human (both group O and A) and guinea pig erythrocytes. None of the strains agglutinated horse erythrocytes in the presence of 1% alpha-D-mannose. It should be emphasized that our data indicate the absence of a relationship between sources and MRHA. In contrast, all 95 strains investigated in this report were negative for MSHA (mannose-sensitive hemagglutination) activity. Regarding hemolysin production, it was seen that E. faecalis, and particularly urinary strains, preferably lysed horse erythrocytes. On the other hand, none of the 95 clinical strains tested in this study showed hemolytic activity against bovine and sheep erythrocytes. In general, these results show that E. faecalis strains isolated from different clinical sources possessed a diversity of hemagglutinins and a limited repertoire of hemolysin activities.
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http://dx.doi.org/10.1016/j.resmic.2005.01.004 | DOI Listing |
PLoS Biol
January 2025
Department of Biophysics, University of Michigan, Ann Arbor, Michigan, United States of America.
As failure rates for traditional antimicrobial therapies escalate, recent focus has shifted to evolution-based therapies to slow resistance. Collateral sensitivity-the increased susceptibility to one drug associated with evolved resistance to a different drug-offers a potentially exploitable evolutionary constraint, but the manner in which collateral effects emerge over time is not well understood. Here, we use laboratory evolution in the opportunistic pathogen Enterococcus faecalis to phenotypically characterize collateral profiles through evolutionary time.
View Article and Find Full Text PDFMicroorganisms
December 2024
Laboratory of Analytic Biochemistry and Biotechnology (LABAB), Department of Biochemistry and Microbiology, Faculty of Biological and Agronomic Sciences, Mouloud Mammeri University, Tizi-Ouzou 15000, Algeria.
The exploration of new pharmacological compounds from endophytic fungi offers infinite possibilities. The aim of this study was to evaluate the antibacterial and antioxidant activities of extracts from the leaves of and five of its endophytic fungi and investigate the chemical diversity of the secondary metabolites produced. Isolated, purified, and molecularly identified endophytes and plant leaves were subjected to ethyl acetate extraction.
View Article and Find Full Text PDFMicroorganisms
December 2024
College of Pharmacy and Inje Institute of Pharmaceutical Sciences and Research, Inje University, Gimhae 50832, Republic of Korea.
The widespread resistance of enterococci to many commonly used antimicrobial agents is a growing concern. Given that the current treatment options for enterococcal infections are limited, the discovery of new therapies, including combination therapies, is necessary. We evaluated double-drug combinations of lefamulin with doxycycline, rifampin, and quinupristin/dalfopristin for in vitro synergy against strains of () and () by using checkerboard and time-kill assays.
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November 2024
Yancheng Academy of Fishery Science, Yancheng 224051, China.
is used as a probiotic in animal and human food supplements. Atmospheric and room temperature plasma (ARTP) systems have frequently been used to screen for effective mutant probiotics. In this study, was treated with ARTP, and high-yielding digestive enzyme mutant strains were obtained by measuring the activities of α-amylase, lipase, and neutral protease.
View Article and Find Full Text PDFLife (Basel)
December 2024
Department of Basic Medical Sciences, College of Medicine, Prince Sattam bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
Catheter-associated urinary tract infections (CAUTIs) cause serious complications among hospitalized patients due to biofilm-forming microorganisms which make treatment ineffective by forming antibiotic-resistant strains. As most CAUTI-causing bacterial pathogens have already developed multidrug resistance, there is an urgent need for alternative antibacterial agents to prevent biofilms on catheter surfaces. As a trial to find out such a potential agent of natural origin, the bark of Rottl.
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