scholarly journals Glycomics Microarrays Reveal Differential In Situ Presentation of the Biofilm Polysaccharide Poly-N-acetylglucosamine on Acinetobacter baumannii and Staphylococcus aureus Cell Surfaces

2020 ◽  
Vol 21 (7) ◽  
pp. 2465
Author(s):  
Andrea Flannery ◽  
Marie Le Berre ◽  
Gerald B. Pier ◽  
James P. O’Gara ◽  
Michelle Kilcoyne

The biofilm component poly-N-acetylglucosamine (PNAG) is an important virulence determinant in medical-device-related infections caused by ESKAPE group pathogens including Gram-positive Staphylococcus aureus and Gram-negative Acinetobacter baumannii. PNAG presentation on bacterial cell surfaces and its accessibility for host interactions are not fully understood. We employed a lectin microarray to examine PNAG surface presentation and interactions on methicillin-sensitive (MSSA) and methicillin-resistant S. aureus (MRSA) and a clinical A. baumannii isolate. Purified PNAG bound to wheatgerm agglutinin (WGA) and succinylated WGA (sWGA) lectins only. PNAG was the main accessible surface component on MSSA but was relatively inaccessible on the A. baumannii surface, where it modulated the presentation of other surface molecules. Carbohydrate microarrays demonstrated similar specificities of S. aureus and A. baumannii for their most intensely binding carbohydrates, including 3′ and 6′sialyllactose, but differences in moderately binding ligands, including blood groups A and B. An N-acetylglucosamine-binding lectin function which binds to PNAG identified on the A. baumannii cell surface may contribute to biofilm structure and PNAG surface presentation on A. baumannii. Overall, these data indicated differences in PNAG presentation and accessibility for interactions on Gram-positive and Gram-negative cell surfaces which may play an important role in biofilm-mediated pathogenesis.

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Anthony D. Verderosa ◽  
Rabeb Dhouib ◽  
Kathryn E. Fairfull-Smith ◽  
Makrina Totsika

ABSTRACT Treatment of biofilm-related Staphylococcus aureus infections represents an important medical challenge worldwide, as biofilms, even those involving drug-susceptible S. aureus strains, are highly refractory to conventional antibiotic therapy. Nitroxides were recently shown to induce the dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here, we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Coadministration of the nitroxide CTEMPO (4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxyl) with ciprofloxacin significantly improved the biofilm eradication activity of the antibiotic against S. aureus. Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced the ciprofloxacin minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter cells localized at the surface and base of the biofilm structure. No toxicity to human cells was observed for the nitroxide CTEMPO or the nitroxide-antibiotic hybrids. Taken together, our results show that nitroxides can mediate the dispersal of Gram-positive biofilms and that dual-acting biofilm eradication antibiotics may provide broad-spectrum therapies for the treatment of biofilm-related infections.


2019 ◽  
Author(s):  
Anthony D. Verderosa ◽  
Rabeb Dhouib ◽  
Kathryn E. Fairfull-Smith ◽  
Makrina Totsika

ABSTRACTTreatment of Staphylococcus aureus biofilm-related infections represents an important medical challenge worldwide, as biofilms, even of drug-susceptible S. aureus strains, are highly refectory to conventional antibiotic therapy. Nitroxides were recently shown to induce dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Co-administration of the nitroxide CTEMPO with ciprofloxacin significantly improved the antibiotic’s biofilm-eradication activity against S. aureus. Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced ciprofloxacin’s minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter into cells localising at the surface and base of the biofilm structure. No toxicity was observed for the nitroxide CTEMPO and the nitroxide-antibiotic hybrids against human cells. Taken together, our results show that nitroxides can mediate dispersal of Gram-positive biofilms and that dual-acting biofilm-eradication antibiotics could provide broad-spectrum therapies for the treatment of biofilm-related infections.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S777-S778
Author(s):  
Arsheena Yassin ◽  
Christine Stavropoulos ◽  
Krystina L Woods ◽  
Jiashan Xu ◽  
Justin Carale ◽  
...  

Abstract Background Hand infections represent a major source of morbidity, which can result in hand stiffness and amputation. Early appropriate empiric antibiotic regimen may reduce the associated morbidity, hence the importance to examine local epidemiology. The aim of this study was to define the current epidemiology of adult hand infections at two urban hospitals in New York City. Methods We performed a double center, retrospective study of adult patients hospitalized from March 2018 to May 2020. Patients with positive cultures associated with the hand infections were included. Retrospectively, 100 patients were reviewed. Data on baseline demographic, clinical, surgical, microbiology, and treatment parameters were collected. Results Of the 100 patients, 76% were male, with median age of 47.5 years (35, 58.25) and average C-reactive protein (CRP) of 50.66 mg/L (± 64.64) on admission (see Table 1). Previous hospitalization within 1 year (38%), previous surgical procedures (39%) and recent IV medication use (26%) were common. 130 bacterial isolates were identified (see Table 2). The most frequent organisms were Gram-positive, with Methicillin susceptible Staphylococcus aureus (MSSA, 25.38%), Streptococcus species (20.08%), and Methicillin resistant Staphylococcus aureus (MRSA, 15.38%) being the most common. Gram-negative organisms were infrequent, with Haemophilus parainfluenzae (3.85%), Enterobacter cloacae (3.85) and Pseudomonas aeruginosa (3.08%) being the most prevalent. Of the 100 patients, 27% had polymicrobial infections, associated with trauma (6%), illicit IV use (6%) and unknown (7%) etiologies. Table 1: Baseline demographics and co-morbid conditions Table 2: Types and numbers of organisms in relation to etiologies Conclusion Within our population, the most common organisms associated with hand infections were Gram-positive, with Staphylococcus aureus and Streptococcus species being the most prevalent. Gram-negative pathogens were infrequently isolated. The results within this study can provide guidance to clinicians on assessing the appropriate empiric antibiotic regimen in patients with hand infections, and can serve as a basis for further studies identifying risk factors associated with isolation of organisms associated with hand infections. Disclosures All Authors: No reported disclosures


2014 ◽  
Vol 8 (3) ◽  
pp. 40-45
Author(s):  
Zina Hashem Shehab ◽  
Huda Suhail Abid ◽  
Sumaya Fadhil Hamad ◽  
Sara Haitham

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.


2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Alexis Peña ◽  
Luis Rojas ◽  
Rosa Aparicio ◽  
Libia Alarcón ◽  
José Gregorio Baptista ◽  
...  

The essential oil of the leaves of Espeletia nana Cuatrec, obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were α-pinene (38.1%), β-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), α-zingiberene (4.0%), and γhimachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923(200 μg/mL) and Enterococcus faecalis ATCC 29212 (600 μg/mL).


2010 ◽  
Vol 5 (1) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Ashraf El-Bassuony ◽  
Sameh AbouZid

A novel prenylated flavanoid, isonymphaeol-D (1), together with two known compounds, isonymphaeol-B (2) and nymphaeol-B (3), were isolated from Egyptian propolis. The structures of the isolated compounds were determined by various spectroscopic methods. 1 exhibited antibacterial activity against Gram-positive (Bacillus cereus, Staphylococcus aureus) and Gram-negative strains (Serratia sp., Pseudomonos sp., Escherichia coli).


2006 ◽  
Vol 72 (10) ◽  
pp. 6687-6692 ◽  
Author(s):  
Sanin Musovic ◽  
Gunnar Oregaard ◽  
Niels Kroer ◽  
Søren J. Sørensen

ABSTRACTThe host range and transfer frequency of an IncP-1 plasmid (pKJK10) among indigenous bacteria in the barley rhizosphere was investigated. A new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16S rRNA gene classification was used. Indigenous transconjugant rhizosphere bacteria were collected by fluorescence-activated cell sorting and identified by cloning and sequencing of 16S rRNA genes from the sorted cells. The host range of the pKJK10 plasmid was exceptionally broad, as it included not only bacteria belonging to the alpha, beta, and gamma subclasses of theProteobacteria, but alsoArthrobactersp., a gram-positive member of theActinobacteria. The transfer frequency (transconjugants per donor) from thePseudomonas putidadonor to the indigenous bacteria was 7.03 × 10−2± 3.84 × 10−2. This is the first direct documentation of conjugal transfer between gram-negative donor and gram-positive recipient bacteria in situ.


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