In our prior research, polymer nanoparticles (NPs) containing tobramycin displayed robust antibacterial efficacy against biofilm-embedded () and (. ) cells, critical pathogens in cystic fibrosis. In the current study, we investigated the deposition of a nanoparticulate carrier composed of poly(d,l-lactic--glycolic acid) (PLGA) and poly(ethylene glycol)--PLGA (PEG-PLGA) that was either covalently bonded with cyanine-5-amine (Cy5) or noncovalently bound with freely embedded cationic rhodamine B (RhB), which served as a drug surrogate.
View Article and Find Full Text PDFPhage therapy has been proposed as a therapeutic alternative to antibiotics for the treatment of chronic, biofilm-related infections. To gain a deeper insight into the complex biofilm-phage interactions, we investigated in the present study the effect of three successive exposures to lytic phages of biofilms formed by the reference strains PAO1 and PA14 as well as of two sequential clinical isolates from the sputum of a patient with cystic fibrosis (CF). The Calgary device was employed as a biofilm model and the efficacy of phage treatment was evaluated by measurements of the biomass stained with crystal violet (CV) and of the cell density of the biofilm bacterial population (CFU/mL) after each of the three phage exposures.
View Article and Find Full Text PDFVancomycin-functionalized micro- or nanoparticles are frequently used for isolation and enrichment of bacteria from various samples. Theoretically, only Gram-positive organisms should adhere to the functionalized surfaces as vancomycin is an antibiotic targeting a peptidoglycan precursor in the cell wall, which in Gram-negative bacteria is shielded by the outer cell membrane. In the literature, however, it is often reported that Gram-negative bacteria also bind efficiently to the vancomycin-modified particles.
View Article and Find Full Text PDFis a highly successful pathogen infecting various body parts and forming biofilms on natural and artificial surfaces resulting in difficult-to-treat and chronic infections. We investigated the secreted cytokines and proteomes of isolated peripheral blood mononuclear cells (PBMCs) from healthy volunteers exposed to methicillin-resistant (MRSA) biofilms or planktonic bacteria. Additionally, the cytokine profiles in sera from patients with community-acquired pneumonia (CAP) caused by were investigated.
View Article and Find Full Text PDFGalleria mellonella larvae have emerged as an invertebrate model for investigating bacterial pathogenesis and potential therapies, addressing ethical concerns related to mammalian models. This model has the advantage of having a simple gut microbiome, which is suitable for gut colonization studies. Intestinal colonization by Enterobacteriaceae significantly contributes to the spread of antibiotic resistance.
View Article and Find Full Text PDFBackground: (PA) is one of the most predominant pathogens of lung infections, often causing exacerbations in adult patients with cystic fibrosis (CF).
Materials And Methods: Microbiological characterization of 74 PA isolates and to evaluate the correlations between the bacterial features and 44 adult Polish CF cohort clinical parameters.
Results: The most common variant in the CF transmembrane conductance regulator () gene was F508del (76.
Phenotypic susceptibility testing of () is an essential tool to gain a better understanding of the potential impact of biocide selection pressure on antimicrobial resistance. We, therefore, determined the biocide and antimicrobial susceptibility of 216 extended-spectrum β-lactamase-producing (ESBL) and 177 non-ESBL isolated from swine feces, pork meat, voluntary donors and inpatients and evaluated associations between their susceptibilities. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of benzalkonium chloride, chlorhexidine digluconate (CHG), chlorocresol (PCMC), glutaraldehyde (GDA), isopropanol (IPA), octenidine dihydrochloride and sodium hypochlorite (NaOCl) showed unimodal distributions, indicating the absence of bacterial adaptation to biocides due to the acquisition of resistance mechanisms.
View Article and Find Full Text PDFThe development of rapid, simple, and accurate bioassays for the detection of nucleic acids has received increasing demand in recent years. Here, localized surface plasmon resonance (LSPR) spectroscopy for the detection of an antimicrobial resistance gene, sulfhydryl variable β-lactamase (blaSHV), which confers resistance against a broad spectrum of β-lactam antibiotics is used. By performing limit of detection experiments, a 23 nucleotide (nt) long deoxyribonucleic acid (DNA) sequence down to 25 nm was detected, whereby the signal intensity is inversely correlated with sequence length (23, 43, 63, and 100 nt).
View Article and Find Full Text PDFNon-linear imaging modalities have enabled us to obtain unique morpho-chemical insights into the tissue architecture of various biological model organisms in a label-free manner. However, these imaging techniques have so far not been applied to analyze the Galleria mellonella infection model. This study utilizes for the first time the strength of multimodal imaging techniques to explore infection-related changes in the Galleria mellonella larvae due to massive E.
View Article and Find Full Text PDFPhages are among the most abundant and diverse biological entities on earth. Phage prediction from sequence data is a crucial first step to understanding their impact on the environment. A variety of bacteriophage prediction tools have been developed over the years.
View Article and Find Full Text PDF, commonly referred to as pneumococci, can cause severe and invasive infections, which are major causes of communicable disease morbidity and mortality in Europe and globally. The differentiation of from other species, especially from other oral streptococci, has proved to be particularly difficult and tedious. In this work, we evaluate if Raman spectroscopy holds potential for a reliable differentiation of from other streptococci.
View Article and Find Full Text PDFAntimicrobial resistance (AMR) is becoming an increasing global concern and the anaerobic digestion (AD) process represents a potential transmission route when digestates are used as fertilizing agents. AMR contaminants, e.g.
View Article and Find Full Text PDFMetagenomic sequencing is promising for clinical applications to study microbial composition concerning disease or patient outcomes. Alterations of the vaginal microbiome are associated with adverse pregnancy outcomes, like preterm premature rupture of membranes and preterm birth. Methodologically these samples often have to deal with low relative amounts of prokaryotic DNA and high amounts of host DNA (> 90%), decreasing the overall microbial resolution.
View Article and Find Full Text PDFFront Cell Infect Microbiol
January 2022
Objective: Brucellosis is a common bacterial zoonotic infection, and greater than half a million new cases are diagnosed annually. This study investigates the expression of Th2 and Th17 immunity-related factors (Th2-LCR lncRNA, IL-25, TRAF3IP2, and IL-17RB) in different stages of infections.
Material And Methods: In total, 99 brucellosis patients were divided into three groups ( = first infection before treatment, = before treatment, and = after treatment for 6-8 weeks with doxycycline and rifampin).
Human milk oligosaccharides (HMOs) have been shown to exhibit plenty of benefits for infants, such as prebiotic activity shaping the gut microbiota and immunomodulatory and anti-inflammatory activity. For some pathogenic bacteria, antimicrobial activity has been proved, but most studies focus on group B streptococci. In the present study, we investigated the antimicrobial and antibiofilm activities of the total and fractionated HMOs from pooled human milk against four common human pathogenic Gram-negative species (, , , and ) and three Gram-positive species (, , and ).
View Article and Find Full Text PDFDalbavancin is a novel glycopeptide antibiotic approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). It is characterized by a potent activity against numerous Gram-positive pathogens, a long elimination half-life and a favorable safety profile. Most recently, its application for the treatment of periprosthetic joint infections (PJIs) was introduced.
View Article and Find Full Text PDFinfective endocarditis is commonly treated with intravenous ampicillin/ceftriaxone combination therapy. Ampicillin, however, is unsuitable for outpatient parenteral antibiotic therapy (OPAT) regimens due to its instability in 24 h continuous infusors, and has been successfully replaced by benzylpenicillin used together with ceftriaxone in a few small case series. Since in vitro synergy data of penicillin/ceftriaxone against are still lacking, checkerboard assays were performed for 28 clinical isolates and one laboratory standard strain.
View Article and Find Full Text PDFBiochemical information from activated leukocytes provide valuable diagnostic information. In this study, Raman spectroscopy was applied as a label-free analytical technique to characterize the activation pattern of leukocyte subpopulations in an in vitro infection model. Neutrophils, monocytes, and lymphocytes were isolated from healthy volunteers and stimulated with heat-inactivated clinical isolates of , , and .
View Article and Find Full Text PDFColony forming unit (CFU) determination by agar plating is still regarded as the gold standard for biofilm quantification despite being time- and resource-consuming. Here, we propose an adaption of the high-throughput Start-Growth-Time (SGT) method from planktonic to biofilm analysis, which indirectly quantifies CFU/mL numbers by evaluating regrowth curves of detached biofilms. For validation, the effect of dalbavancin, rifampicin and gentamicin against mature biofilms of and was measured by accessing different features of the viability status of the cell, i.
View Article and Find Full Text PDFSingle substitutions or combinations of them alter the hydrolytic activity towards specific β-lactam-antibiotics and β-lactamase inhibitors of TEM-β-lactamases. The sequences and phenotypic classification of allelic TEM variants, as provided by the NCBI National Database of Antibiotic Resistant Organisms, does not attribute phenotypes to all variants. Some entries are doubtful as the data assessment differs strongly between the studies or no data on the methodology are provided at all.
View Article and Find Full Text PDFThis study investigated the prevalence of (.) isolates among clinical samples of patients in four medical centers in Lagos, Nigeria and the burden of extended-spectrum beta-lactamases (ESBL) and carbapenem-resistant (CRKP) strains. Different samples (stool, blood, urine, wound swabs and nasal swabs) from 127 patients with suspected Gram-negative infections based on on-site performed Gram-stain from four public hospitals between March and September 2015 were analyzed.
View Article and Find Full Text PDFA primiparous pregnant woman was admitted due to preterm premature rupture of membranes (PPROM) at 27+0 week of gestational age (WGA). Conventional vaginal microbiological analysis had no pathological finding. Management decisions based on national guidelines included antenatal corticoids, tocolytics and antibiotics.
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