scholarly journals Detection of Streptococcus suis in Bioaerosols of Swine Confinement Buildings

2014 ◽  
Vol 80 (11) ◽  
pp. 3296-3304 ◽  
Author(s):  
Laetitia Bonifait ◽  
Marc Veillette ◽  
Valérie Létourneau ◽  
Daniel Grenier ◽  
Caroline Duchaine
Keyword(s):  
Membrane Integrity ◽  
Streptococcus Suis ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Swine Pathogen ◽  
Swine Confinement ◽  
Nasal Swabs ◽  
Qpcr Method ◽  
Human Infections ◽  
Number Of Bacteria

ABSTRACTStreptococcus suisis an important swine pathogen that can cause septicemia, meningitis, and pneumonia. Also recognized as an emerging zoonotic agent, it is responsible for outbreaks of human infections in Asian countries. Serotype 2 is the predominant isolate from diseased animals and humans. The aerosolization ofS. suisin the air of swine confinement buildings (SCB) was studied. The presence ofS. suisin bioaerosols was monitored in SCB where cases of infection had been reported and in healthy SCB without reported infections. Using a quantitative-PCR (qPCR) method, we determined the total number of bacteria (1 × 108to 2 × 108airborne/m3), total number ofS. suisbacteria (4 × 105to 10 × 105airborne/m3), and number ofS. suisserotype 2 and 1/2 bacteria (1 × 103to 30 × 103airborne/m3) present in the air.S. suisserotypes 2 and 1/2 were detected in the air of all growing/finishing SCB that had documented cases ofS. suisinfection and in 50% of healthy SCB. The total number of bacteria and total numbers ofS. suisandS. suisserotype 2 and 1/2 bacteria were monitored in one positive SCB during a 5-week period, and it was shown that the aerosolizedS. suisserotypes 2 and 1/2 remain airborne for a prolonged period. When the effect of aerosolization onS. suiswas observed, the percentage of intactS. suisbacteria (showing cell membrane integrity) in the air might have been up to 13%. FinallyS. suiswas found in nasal swabs from 14 out of 21 healthy finishing-SCB workers, suggesting significant exposure to the pathogen. This report provides a better understanding of the aerosolization, prevalence, and persistence ofS. suisin SCB.

scholarly journals Pseudomonas aeruginosa Alginate Benefits Staphylococcus aureus?

2020 ◽  
Vol 202 (8) ◽  
Author(s):  
Michael J. Schurr
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Cell Membrane ◽  
Membrane Integrity ◽  
Partial Explanation ◽  
Content Type ◽  
First Report ◽  
Cell Membrane Integrity ◽  
Link Type

ABSTRACT In this issue of Journal of Bacteriology, Price et al. show that the Pseudomonas aeruginosa-produced exopolysaccharide alginate protects Staphylococcus aureus by dampening the expression of P. aeruginosa virulence products that usually inhibit S. aureus respiration and cell membrane integrity when the two organisms compete in other environments (C. E. Price, D. G. Brown, D. H. Limoli, V. V. Phelan, and G. A. O’Toole, J Bacteriol 202:e00559-19, 2020, https://doi.org/10.1128/jb.00559-19). This is the first report that exogenously added alginate affects P. aeruginosa competition and provides a partial explanation for S. aureus and P. aeruginosa coinfections in cystic fibrosis.

Evolution of tissue damage in compressive spinal cord injury in rats

1987 ◽  
Vol 66 (4) ◽  
pp. 595-603 ◽  
Author(s):  
Hideaki Iizuka ◽  
Hirotaka Yamamoto ◽  
Yuzo Iwasaki ◽  
Teiji Yamamoto ◽  
Hidehiko Konno
Keyword(s):  
Spinal Cord ◽  
Tissue Damage ◽  
Spinal Cord Injuries ◽  
Sodium Dodecyl ◽  
Membrane Integrity ◽  
Secondary Degeneration ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Cord Injury ◽  
Mechanical Insult

✓ The evolution of tissue damage in compressive spinal cord injuries in rats was studied using an immunohistochemical technique and by sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) analysis. The rupture of small vessels accompanied by intense tissue permeation of serum components in and around the hemorrhagic foci appeared to be immediate consequences of the mechanical insult. The loss of cell membrane integrity in neural elements became evident within 1 hour after injury as shown by the diffuse albumin-immunoreactivity of the cytoplasm. At the site of mechanical insult, approximately 30% of the neurofilament proteins were degraded within 1 hour, and 70% of them were lost within 4 hours after injury. A large number of cells positive for glial fibrillary acidic protein were found to demarcate the injured tissue within 1 hour after injury. The progression of tissue damage largely subsided within 48 hours. One week after, injury, severe degeneration of the ascending tracts in the posterior funiculus was shown clearly by axon staining and less convincingly by myelin staining. Secondary degeneration of the corticospinal tract in distal segments remained inconspicuous for up to 3 months.

scholarly journals Altering the Proclivity towards Daptomycin Resistance in Methicillin-Resistant Staphylococcus aureus Using Combinations with Other Antibiotics

2012 ◽  
Vol 56 (10) ◽  
pp. 5046-5053 ◽  
Author(s):  
Andrew D. Berti ◽  
Justine E. Wergin ◽  
Gary G. Girdaukas ◽  
Scott J. Hetzel ◽  
George Sakoulas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Membrane ◽  
Membrane Integrity ◽  
Wall Thickening ◽  
Methicillin Resistant ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Cell Membrane Fluidity

ABSTRACTDaptomycin (DAP) is increasingly used as a part of combination therapy, particularly in complex methicillin-resistantStaphylococcus aureus(MRSA) infections. While multiple studies have reported the potential for synergy between DAP and adjunctive anti-infectives, few have examined the influence of adjunctive therapy on the emergence of DAP resistance. This study examined eight adjunctive antimicrobial combinations with DAPin vitroand the emergence of DAP resistance over time (up to 4 weeks) using clinical isolates of DAP-susceptible MRSA (MIC, 0.5 μg/ml) in which DAP resistance subsequently developed during patient therapy (MIC, 3 μg/ml). In addition to DAP susceptibility testing, selected strains were examined for phenotypic changes associated with DAP resistance, including changes to cell wall thickness (CWT) and cell membrane alterations. The addition of either oxacillin or clarithromycin in medium containing DAP significantly inhibited the development of DAP resistance through the entirety of the 4-week exposure (10- to 32-fold MIC reduction from that of DAP alone). Combinations with rifampin or fosfomycin were effective in delaying the emergence of DAP resistance through the end of week one only (week one MIC, 0.5 μg/ml; week four MIC, 24 μg/ml). Cell wall thickening was observed for all antibiotic combinations regardless of their effect on the DAP MIC (14 to 70% increase in CWT), while changes in cell membrane fluidity were variable and treatment dependent. DAP showed reduced activity against strains with DAP MICs of 1 to 12 μg/ml, but cell membrane integrity was still disrupted at concentrations achieved with doses greater than 10 mg/kg of body weight. The emergence of DAP resistance in MRSA is strongly influenced by the presence of subinhibitory concentrations of adjunctive antimicrobials. These data suggest that combining DAP with oxacillin or clarithromycin may delay the development of DAP resistance in cases requiring prolonged antibiotic therapy.

scholarly journals Draft Genome Sequence of Clinical Strain TANI1 of Streptococcus suis Serotype 5 Isolated from a Bacteremia Patient in Japan

2017 ◽  
Vol 5 (18) ◽  
Author(s):  
Haruno Yoshida ◽  
Takayuki Wada ◽  
Daisuke Taniyama ◽  
Takashi Takahashi
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Streptococcus Suis ◽  
Draft Genome Sequence ◽  
Clinical Strain ◽  
Economic Damage ◽  
Content Type ◽  
Swine Pathogen ◽  
Serotype 5 ◽  
Suis Serotype

ABSTRACT Streptococcus suis is a swine pathogen that causes severe economic damage to the porcine industry. It occasionally evokes zoonotic infection in humans. Here, we report a draft genome sequence of a S. suis serotype 5 strain isolated from a bacteremia patient that was reported by Taniyama et al. (D. Taniyama, M. Sakurai, T. Sakai, T. Kikuchi, and T. Takahashi, IDCases 6:36–38, 2016, https://doi.org/10.1016/j.idcr.2016.09.011 ).

scholarly journals Antifungal Activity of Mammalian Serum Amyloid A1 against Candida albicans

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Jiao Gong ◽  
Jun Wu ◽  
Melanie Ikeh ◽  
Li Tao ◽  
Yulong Zhang ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Membrane Integrity ◽  
Systemic Infection ◽  
Serum Amyloid ◽  
Infection Model ◽  
Fungal Cell ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Amyloid A

ABSTRACT Mammalian serum amyloid A (SAA) is a major acute phase protein that shows a massive increase in plasma concentration during inflammation. In the present study, we demonstrate that the expression of mouse SAA1 in serum was increased when infected with Candida albicans, a major human fungal pathogen, in a systemic infection model. We then set out to investigate the antifungal activity of SAA proteins against C. albicans. Recombinant human and mouse SAA1 (rhSAA1 and rmSAA1) were expressed and purified in Escherichia coli. Both rhSAA1 and rmSAA1 exhibited a potent antifungal activity against C. albicans. We further demonstrate that rhSAA1 binds to the cell surface of C. albicans, disrupts cell membrane integrity, and induces rapid fungal cell death in C. albicans. Our finding expands the known functions of SAA1 and provides new insight into host-Candida interactions during fungal infection.

scholarly journals Amoeba Host Model for Evaluation of Streptococcus suis Virulence

2011 ◽  
Vol 77 (17) ◽  
pp. 6271-6273 ◽  
Author(s):  
Laetitia Bonifait ◽  
Steve J. Charette ◽  
Geneviève Filion ◽  
Marcelo Gottschalk ◽  
Daniel Grenier
Keyword(s):  
Dictyostelium Discoideum ◽  
Streptococcus Suis ◽  
Relevant Alternative ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Content Type ◽  
Alternative System ◽  
Swine Pathogen

ABSTRACTThe Gram-positive bacteriumStreptococcus suisis a major swine pathogen worldwide that causes meningitis, septicemia, and endocarditis. In this study, we demonstrate that the amoebaDictyostelium discoideumcan be a relevant alternative system to study the virulence ofS. suis.

scholarly journals Thermal and Nonthermal Effects of Discontinuous Microwave Exposure (2.45 Gigahertz) on the Cell Membrane of Escherichia coli

2014 ◽  
Vol 80 (16) ◽  
pp. 4832-4841 ◽  
Author(s):  
Carole Rougier ◽  
Audrey Prorot ◽  
Philippe Chazal ◽  
Philippe Leveque ◽  
Patrick Leprat
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Cell Membranes ◽  
Membrane Integrity ◽  
Threshold Effect ◽  
Cell Suspensions ◽  
Conventional Heating ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Average Temperature

ABSTRACTThe aim of this study was to investigate the effects on the cell membranes ofEscherichia coliof 2.45-GHz microwave (MW) treatment under various conditions with an average temperature of the cell suspension maintained at 37°C in order to examine the possible thermal versus nonthermal effects of short-duration MW exposure. To this purpose, microwave irradiation of bacteria was performed under carefully defined and controlled parameters, resulting in a discontinuous MW exposure in order to maintain the average temperature of the bacterial cell suspensions at 37°C.Escherichia colicells were exposed to 200- to 2,000-W discontinuous microwave (DW) treatments for different periods of time. For each experiment, conventional heating (CH) in a water bath at 37°C was performed as a control. The effects of DW exposure on cell membranes was investigated using flow cytometry (FCM), after propidium iodide (PI) staining of cells, in addition to the assessment of intracellular protein release in bacterial suspensions. No effect was detected when bacteria were exposed to conventional heating or 200 W, whereas cell membrane integrity was slightly altered when cell suspensions were subjected to powers ranging from 400 to 2,000 W. Thermal characterization suggested that the temperature reached by the microwave-exposed samples for the contact time studied was not high enough to explain the measured modifications of cell membrane integrity. Because the results indicated that the cell response is power dependent, the hypothesis of a specific electromagnetic threshold effect, probably related to the temperature increase, can be advanced.

scholarly journals Requirement of a Tsp2-Type Tetraspanin for Laccase Repression and Stress Resistance in the Basidiomycete Cryptococcus neoformans

2011 ◽  
Vol 78 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Zhongming Li ◽  
Jiannan Bi ◽  
Jiao Yang ◽  
Jiao Pan ◽  
Zhixiong Sun ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Stress Resistance ◽  
Glucose Repression ◽  
Membrane Integrity ◽  
Content Type ◽  
Cell Membrane Integrity ◽  
Underlying Basis ◽  
Dependent Protein ◽  
Pka Pathway ◽  
First Time

ABSTRACTFungal laccases have been widely used in industry. The expression of laccase often is repressible by the primary carbon source glucose in many fungi. The underlying basis is largely unclear. We demonstrate here that a gene,TSP2-1, was required for laccase repression by glucose in the basidiomyceteCryptococcus neoformans.TSP2-1encodes a Tsp2-type tetraspanin. The disruption ofTSP2-1resulted in constant melanin formation and the expression of the laccase geneLAC1. This derepression phenotype was restorable by 10 mM exogenous cyclic AMP (cAMP). A capsule defect in the mutanttsp2-1Δ also was restored by cAMP. The results indicate an interaction of Tsp2-1 with the cAMP-dependent protein kinase A (PKA) pathway that has been shown to modulate laccase repression and capsule biosynthesis in this fungus. Other roles ofTSP2-1, e.g., in maintaining cell membrane integrity and stress resistance, also were defined. This work reveals a Tsp2-1-dependent glucose repression inC. neoformans. The function of Tsp2-type tetraspanin Tsp2-1 is described for the first time.

scholarly journals Complete Genome Sequence of Streptococcus suis Serotype 2 Virulent Strain SS2-1

2018 ◽  
Vol 6 (10) ◽  
Author(s):  
Haodan Zhu ◽  
Yanxiu Ni ◽  
Junming Zhou ◽  
Zhengyu Yu ◽  
Aihua Mao ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Virulent Strain ◽  
Streptococcus Suis ◽  
Jiangsu Province ◽  
Content Type ◽  
Swine Pathogen ◽  
Suis Serotype ◽  
Streptococcus Suis Serotype 2

ABSTRACT Streptococcus suis is an important swine pathogen that can also cause severe diseases in humans. Herein, we describe the genome sequence of Streptococcus suis serotype 2 virulent strain SS2-1, which was isolated from a diseased dead pig amid the 1998 Streptococcus suis outbreak in Jiangsu Province in China.

scholarly journals Streptococcus suis Capsular Polysaccharide Inhibits Phagocytosis through Destabilization of Lipid Microdomains and Prevents Lactosylceramide-Dependent Recognition

2011 ◽  
Vol 80 (2) ◽  
pp. 506-517 ◽  
Author(s):  
Mathieu Houde ◽  
Marcelo Gottschalk ◽  
Fleur Gagnon ◽  
Marie-Rose Van Calsteren ◽  
Mariela Segura
Keyword(s):  
Molecular Mechanisms ◽  
Capsular Polysaccharide ◽  
Streptococcus Suis ◽  
No Production ◽  
Lipid Microdomains ◽  
Content Type ◽  
Swine Pathogen ◽  
Latex Beads ◽  
Covalently Linked

ABSTRACTStreptococcus suistype 2 is a major swine pathogen and a zoonotic agent, causing meningitis in both swine and humans.S. suisinfects the host through the respiratory route, reaches the bloodstream, and persists until breaching into the central nervous system. The capsular polysaccharide (CPS) ofS. suistype 2 is considered a key virulence factor of the bacteria. Though CPS allowsS. suisto adhere to the membrane of cells of the immune system, it provides protection against phagocytosis. In fact, nonencapsulated mutants are easily internalized and killed by macrophages and dendritic cells. The objective of this work was to study the molecular mechanisms by which the CPS ofS. suisprevents phagocytosis. By using latex beads covalently linked with purified CPS, it was shown that CPS itself was sufficient to inhibit entry of both latex beads and bystander fluorescent beads into macrophages. Upon contact with macrophages, encapsulatedS. suiswas shown to destabilize lipid microdomains at the cell surface, to block nitric oxide (NO) production during infection, and to prevent lactosylceramide accumulation at the phagocytic cup during infection. In contrast, the nonencapsulated mutant was easily internalized via lipid rafts, in a filipin-sensitive manner, leading to lactosylceramide recruitment and strong NO production. This is the first report to identify a role for CPS in lipid microdomain stability and to recognize an interaction betweenS. suisand lactosylceramide in phagocytes.

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