scholarly journals Clinical Impact of the Expanded BioFire Blood Culture Identification 2 Panel in a U.S. Children’s Hospital

2021 ◽  
Author(s):  
Kelly E. Graff ◽  
Claire Palmer ◽  
Toraj Anarestani ◽  
Darcy Velasquez ◽  
Stacey Hamilton ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Negative Resistance ◽  
Clinical Impact ◽  
Gene Detection ◽  
Gram Negative ◽  
Content Type ◽  
Standard Culture ◽  
Enterococcal Species ◽  
Content Identification ◽  
Culture Identification

The BioFire BCID2 panel is an accurate panel that is equivalent to the BioFire BCID panel compared to standard culture. The BioFire BCID2 panel offers several advantages over the BioFire BCID panel, including enterococcal species identification, Gram-negative resistance gene detection, Salmonella identification, and the added mecA / mecC and MREJ target for better Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS) differentiation.

scholarly journals Nitroxide Functionalized Antibiotics Are Promising Eradication Agents against Staphylococcus aureus Biofilms

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Anthony D. Verderosa ◽  
Rabeb Dhouib ◽  
Kathryn E. Fairfull-Smith ◽  
Makrina Totsika
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Biofilms ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Microscopy Analysis ◽  
Biofilm Dispersal ◽  
Biofilm Structure ◽  
Dispersal Activity

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.

scholarly journals The ω Subunit Governs RNA Polymerase Stability and Transcriptional Specificity in Staphylococcus aureus

2016 ◽  
Vol 199 (2) ◽  
Author(s):  
Andy Weiss ◽  
Brittney D. Moore ◽  
Miguel H. J. Tremblay ◽  
Dale Chaput ◽  
Astrid Kremer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Rna Polymerase ◽  
Gram Negative Bacteria ◽  
Sequencing Analysis ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Successful Infection ◽  
Transcriptional Changes ◽  
First Time

ABSTRACT Staphylococcus aureus is a major human pathogen that causes infection in a wide variety of sites within the human body. Its ability to adapt to the human host and to produce a successful infection requires precise orchestration of gene expression. While DNA-dependent RNA polymerase (RNAP) is generally well characterized, the roles of several small accessory subunits within the complex have yet to be fully explored. This is particularly true for the omega (ω or RpoZ) subunit, which has been extensively studied in Gram-negative bacteria but largely neglected in Gram-positive counterparts. In Escherichia coli, it has been shown that ppGpp binding, and thus control of the stringent response, is facilitated by ω. Interestingly, key residues that facilitate ppGpp binding by ω are not conserved in S. aureus, and consequently, survival under starvation conditions is unaffected by rpoZ deletion. Further to this, ω-lacking strains of S. aureus display structural changes in the RNAP complex, which result from increased degradation and misfolding of the β′ subunit, alterations in δ and σ factor abundance, and a general dissociation of RNAP in the absence of ω. Through RNA sequencing analysis we detected a variety of transcriptional changes in the rpoZ-deficient strain, presumably as a response to the negative effects of ω depletion on the transcription machinery. These transcriptional changes translated to an impaired ability of the rpoZ mutant to resist stress and to fully form a biofilm. Collectively, our data underline, for the first time, the importance of ω for RNAP stability, function, and cellular physiology in S. aureus. IMPORTANCE In order for bacteria to adjust to changing environments, such as within the host, the transcriptional process must be tightly controlled. Transcription is carried out by DNA-dependent RNA polymerase (RNAP). In addition to its major subunits (α2ββ′) a fifth, smaller subunit, ω, is present in all forms of life. Although this small subunit is well studied in eukaryotes and Gram-negative bacteria, only limited information is available for Gram-positive and pathogenic species. In this study, we investigated the structural and functional importance of ω, revealing key roles in subunit folding/stability, complex assembly, and maintenance of transcriptional integrity. Collectively, our data underline, for the first time, the importance of ω for RNAP function and cellular harmony in S. aureus.

scholarly journals Co-infection in critically ill patients with COVID-19: an observational cohort study from England

2021 ◽  
Vol 70 (4) ◽  
Author(s):  
Vadsala Baskaran ◽  
Hannah Lawrence ◽  
Louise E. Lansbury ◽  
Karmel Webb ◽  
Shahideh Safavi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cohort Study ◽  
Streptococcus Pneumoniae ◽  
Critically Ill ◽  
Type Species ◽  
Severe Illness ◽  
Gram Negative ◽  
Content Type ◽  
Link Type ◽  
Icu Stay

Introduction. During previous viral pandemics, reported co-infection rates and implicated pathogens have varied. In the 1918 influenza pandemic, a large proportion of severe illness and death was complicated by bacterial co-infection, predominantly Streptococcus pneumoniae and Staphylococcus aureus . Gap statement. A better understanding of the incidence of co-infection in patients with COVID-19 infection and the pathogens involved is necessary for effective antimicrobial stewardship. Aim. To describe the incidence and nature of co-infection in critically ill adults with COVID-19 infection in England. Methodology. A retrospective cohort study of adults with COVID-19 admitted to seven intensive care units (ICUs) in England up to 18 May 2020, was performed. Patients with completed ICU stays were included. The proportion and type of organisms were determined at <48 and >48 h following hospital admission, corresponding to community and hospital-acquired co-infections. Results. Of 254 patients studied (median age 59 years (IQR 49–69); 64.6 % male), 139 clinically significant organisms were identified from 83 (32.7 %) patients. Bacterial co-infections/ co-colonisation were identified within 48 h of admission in 14 (5.5 %) patients; the commonest pathogens were Staphylococcus aureus (four patients) and Streptococcus pneumoniae (two patients). The proportion of pathogens detected increased with duration of ICU stay, consisting largely of Gram-negative bacteria, particularly Klebsiella pneumoniae and Escherichia coli . The co-infection/ co-colonisation rate >48 h after admission was 27/1000 person-days (95 % CI 21.3–34.1). Patients with co-infections/ co-colonisation were more likely to die in ICU (crude OR 1.78,95 % CI 1.03–3.08, P=0.04) compared to those without co-infections/ co-colonisation. Conclusion. We found limited evidence for community-acquired bacterial co-infection in hospitalised adults with COVID-19, but a high rate of Gram-negative infection acquired during ICU stay.

scholarly journals Rapid Detection of Methicillin-Resistant Staphylococcus aureus and Methicillin-Susceptible S. aureus Directly from Positive Blood Cultures by Use of the BD Max StaphSR Assay

2015 ◽  
Vol 53 (12) ◽  
pp. 3900-3904 ◽  
Author(s):  
Justin A. Ellem ◽  
Tom Olma ◽  
Matthew V. N. O'Sullivan
Keyword(s):  
Staphylococcus Aureus ◽  
Predictive Value ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Direct Detection ◽  
Blood Cultures ◽  
Coagulase Negative Staphylococcus ◽  
Methicillin Resistant ◽  
Content Type ◽  
Standard Culture

The BD Max StaphSR assay is an automated qualitativein vitrodiagnostic test for the direct detection and differentiation of methicillin-susceptibleStaphylococcus aureus(MSSA) and methicillin-resistantS. aureus(MRSA). A total of 460 specimens were tested, and the results were compared with standard culture-based identification. MRSA was detected in 48 samples (sensitivity of 100%; positive predictive value [PPV] of 100%). MSSA was detected in 112 samples (sensitivity of 99.1%; PPV of 100%), and 299 samples containing coagulase-negative staphylococcus and nonstaphylococcal species were negative by the BD Max StaphSR assay (specificity of 100%; negative predictive value [NPV] of 99.7 to 100%).

scholarly journals Efficacy of Ceftaroline Fosamil against Penicillin-Sensitive and -Resistant Streptococcus pneumoniae in an Experimental Rabbit Meningitis Model

2013 ◽  
Vol 57 (10) ◽  
pp. 4653-4655 ◽  
Author(s):  
P. Cottagnoud ◽  
M. Cottagnoud ◽  
F. Acosta ◽  
A. Stucki
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Bactericidal Activity ◽  
Resistant Strain ◽  
Gram Positive ◽  
Ceftaroline Fosamil ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Content Type ◽  
Gram Negative Organisms

ABSTRACTCeftaroline is a new cephalosporin with bactericidal activity against resistant Gram-positive organisms, including methicillin-resistantStaphylococcus aureus(MRSA) and penicillin-resistantStreptococcus pneumoniae, as well as common Gram-negative organisms. This study tested the prodrug, ceftaroline fosamil, against a penicillin-sensitive and a penicillin-resistant strain ofS. pneumoniaein an experimental rabbit meningitis model. The penetration of ceftaroline into inflamed meninges was approximately 14%. Ceftaroline fosamil was slightly superior to ceftriaxone against the penicillin-sensitive strain and significantly superior to the combination of ceftriaxone and vancomycin against the penicillin-resistant strain.

scholarly journals Daptomycin in Combination with Ceftolozane-Tazobactam or Cefazolin against Daptomycin-Susceptible and -Nonsusceptible Staphylococcus aureus in anIn Vitro, Hollow-Fiber Model

2016 ◽  
Vol 60 (7) ◽  
pp. 3970-3975 ◽  
Author(s):  
Jordan R. Smith ◽  
Anu Arya ◽  
Juwon Yim ◽  
Katie E. Barber ◽  
Jessica Hallesy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Hollow Fiber ◽  
Synergistic Activity ◽  
Beta Lactamase ◽  
Beta Lactams ◽  
Gram Negative ◽  
Content Type ◽  
Mrsa Strains ◽  
Lactamase Inhibitor

ABSTRACTCeftolozane-tazobactam (TOL-TAZ) is a novel cephalosporin/beta-lactamase inhibitor with activity against several Gram-negative pathogens. Daptomycin (DAP) has demonstrated synergistic activity with beta-lactams against methicillin-resistantStaphylococcus aureus(MRSA) isolates with reduced lipopeptide and glycopeptide susceptibilities. Our objective was to determine if DAP and TOL-TAZ possess synergy in hollow-fiber pharmacokinetic/pharmacodynamic (PK/PD) models. One isogenic pair of daptomycin-susceptible and daptomycin-nonsusceptible MRSA strains was evaluated. DAP, TOL-TAZ, and cefazolin (CFZ) MIC determinations were performed. DAP MIC determinations were also performed in the presence of subinhibitory concentrations of TOL-TAZ and CFZ. Ninety-six-hourin vitromodels were run, simulating DAP at 10 mg/kg of body weight/day; TOL-TAZ at 1,500 mg every 8 h; TOL at 1,000 mg every 8 h; and DAP combined with TOL-TAZ (DAP+TOL-TAZ), DAP+TOL, DAP+TAZ, and DAP+CFZ at 2,000 mg every 8 h. DAP MICs were 0.5 and 4 μg/ml for strains R8845 and R8846, respectively. In the presence of CFZ, R8845 and R8846 DAP MICs were reduced 8-fold and 16-fold, respectively. TOL and TAZ had no effect on DAP MICs. PK/PD models demonstrated bactericidal activity with DAP+CFZ against both strains. The combination of DAP+TOL-TAZ was bactericidal against R8845 but was not bactericidal against daptomycin-nonsusceptible strain R8846. DAP+TOL and DAP+TAZ were not bactericidal. No other regimens were bactericidal. DAP+TOL-TAZ did not demonstrate synergistic activity against daptomycin-nonsusceptibleS. aureusbut prevented daptomycin-nonsusceptible MRSA emergence. Because DAP+TOL or TAZ alone did not prevent daptomycin-nonsusceptible MRSA emergence, the combination TOL-TAZ may be necessary for synergy with DAP. DAP+CFZ demonstrated enhancement against both strains. The combination of DAP+CFZ warrants further clinical study.

Progress towards a coordinated, national paediatric antimicrobial resistance surveillance programme: Staphylococcus aureus, enterococcal and Gram-negative bacteraemia in Australia

2020 ◽  
Vol 75 (6) ◽  
pp. 1639-1644
Author(s):  
Anita J Campbell ◽  
Denise A Daley ◽  
Jan M Bell ◽  
Stanley Pang ◽  
Geoffrey W Coombs ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Bloodstream Infections ◽  
Negative Resistance ◽  
Data Set ◽  
Surveillance Programme ◽  
Gram Negative ◽  
Antimicrobial Resistance Surveillance ◽  
Nationally Representative ◽  
Molecular Phenotypes

Abstract Background There is increasing knowledge of antimicrobial usage in children yet limited availability of nationally representative paediatric-specific data on antimicrobial resistance. Objectives Paediatric data from this national surveillance programme are presented to explore differences between childhood and adult bloodstream infections and antimicrobial resistance surveillance. Methods Using information collected from a prospective coordinated antimicrobial resistance surveillance programme, children ≤18 years and adults &gt;18 years with a positive blood culture for Staphylococcus aureus, Enterococcus spp. or Gram-negative spp. presenting to one of 34 Australian hospitals during 2013–16 were evaluated. Consistent methodologies for key sepsis pathogens were employed and a comparative analysis between children and adults was conducted. Results There are stark contrasts between children and adults in this national antimicrobial resistance (AMR) data set. Notable differences include lower rates of AMR, different clinical and molecular phenotypes and lower mortality amongst children. The burden of Gram-negative resistance is disproportionately experienced in children, with higher odds of death with an ESBL versus non-ESBL bacteraemia in comparison with adults. Conclusions These data support that children are not just ‘little adults’ in the AMR era, and analyses by age group are important to detect differences in antibiotic susceptibility, clinical phenotype and genetic virulence factors. Antimicrobial surveillance incorporated into routine laboratory practice is vital to inform an array of wider applications including antimicrobial guidelines, stewardship and direction for prioritization of novel antimicrobial development.

scholarly journals ComparativeIn VitroActivities of SMT19969, a New Antimicrobial Agent, against Clostridium difficile and 350 Gram-Positive and Gram-Negative Aerobic and Anaerobic Intestinal Flora Isolates

2013 ◽  
Vol 57 (10) ◽  
pp. 4872-4876 ◽  
Author(s):  
Ellie J. C. Goldstein ◽  
Diane M. Citron ◽  
Kerin L. Tyrrell ◽  
C. Vreni Merriam
Keyword(s):  
Staphylococcus Aureus ◽  
Clostridium Difficile ◽  
Intestinal Flora ◽  
Colonization Resistance ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Aerobic And Anaerobic ◽  
Group Species

ABSTRACTThe comparativein vitroactivity of SMT19969, a novel, narrow-spectrum, nonabsorbable agent, was studied against 50 ribotype-definedClostridium difficilestrains, 174 Gram-positive and 136 Gram-negative intestinal anaerobes, and 40 Gram-positive aerobes. SMT19969 was one dilution more active againstC. difficileisolates (MIC range, 0.125 to 0.5 μg/ml; MIC90, 0.25 μg/ml), including ribotype 027 strains, than fidaxomicin (range, 0.06 to 1 μg/ml; MIC90, 0.5 μg/ml) and two to six dilutions lower than either vancomycin or metronidazole. SMT19969 and fidaxomicin were generally less active against Gram-negative anaerobes, especially theBacteroides fragilisgroup species, than vancomycin and metronidazole, suggesting that SMT19969 has a lesser impact on the normal intestinal microbiota that maintain colonization resistance. SMT19969 showed limited activity against other Gram-positive anaerobes, includingBifidobacteriaspecies,Eggerthella lenta,Finegoldia magna, andPeptostreptococcus anaerobius, with MIC90s of >512, >512, 64, and 64 μg/ml, respectively.Clostridiumspecies showed various levels of susceptibility, withC. innocuumbeing susceptible (MIC90, 1 μg/ml) andC. ramosumandC. perfringensbeing nonsusceptible (MIC90, >512 μg/ml). Activity againstLactobacillusspp. (range, 0.06 to >512 μg/ml; MIC90, >512 μg/ml) was comparable to that of fidaxomicin and varied by species and strain. Gram-positive aerobic cocci (Staphylococcus aureus,Enterococcus faecalis,E. faecium, and streptococci) showed high SMT19969 MIC90values (128 to >512 μg/ml).

scholarly journals A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

2013 ◽  
Vol 79 (11) ◽  
pp. 3511-3515 ◽  
Author(s):  
Edwige Van der Heiden ◽  
Michaël Delmarcelle ◽  
Sarah Lebrun ◽  
Régine Freichels ◽  
Alain Brans ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Cluster ◽  
Bacillus Licheniformis ◽  
Klebsiella Oxytoca ◽  
Negative Bacterium ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Bacterium Bacillus

ABSTRACTWe report the first identification of a gene cluster involved ind-tagatose catabolism inBacillus licheniformis. The pathway is closely related to thed-tagatose pathway of the Gram-negative bacteriumKlebsiella oxytoca, in contrast to thed-tagatose 6-phosphate pathway described in the Gram-positive bacteriumStaphylococcus aureus.

scholarly journals Comparison ofIn VivoandIn VitroPharmacodynamics of a Humanized Regimen of 600 Milligrams of Ceftaroline Fosamil Every 12 Hours against Staphylococcus aureus at Initial Inocula of 106and 108CFU per Milliliter

2014 ◽  
Vol 58 (11) ◽  
pp. 6931-6933 ◽  
Author(s):  
Wonhee So ◽  
Jared L. Crandon ◽  
George G. Zhanel ◽  
David P. Nicolau
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Model ◽  
Beta Lactams ◽  
Ceftaroline Fosamil ◽  
Gram Negative ◽  
Content Type ◽  
Inoculum Effect

ABSTRACTIn light of thein vivo/in vitrodiscordance among beta-lactams against Gram-negative pathogens, we compared thein vivopharmacodynamics of humanized ceftaroline against 9Staphylococcus aureusstrains (MICs of 0.13 to 1 mg/liter) from publishedin vitrostudies using standard and high inocula in the murine thigh infection model. Consistent with thein vitrofindings, mean reductions of ≥1 log10CFU were observed for ceftaroline against all strains using both standard and high inocula. These results suggestin vivo/in vitroconcordance with no observed inoculum effect.

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