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result(s) for
"Staphylococcus aureus - drug effects"
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Chlorhexidine versus routine bathing to prevent multidrug-resistant organisms and all-cause bloodstream infections in general medical and surgical units (ABATE Infection trial): a cluster-randomised trial
by
Perlin, Jonathan B
,
Gombosev, Adrijana
,
Forehand, Tyler
in
Administration, Intranasal
,
Aged
,
Anti-Infective Agents, Local - administration & dosage
2019
Universal skin and nasal decolonisation reduces multidrug-resistant pathogens and bloodstream infections in intensive care units. The effect of universal decolonisation on pathogens and infections in non-critical-care units is unknown. The aim of the ABATE Infection trial was to evaluate the use of chlorhexidine bathing in non-critical-care units, with an intervention similar to one that was found to reduce multidrug-resistant organisms and bacteraemia in intensive care units.
The ABATE Infection (active bathing to eliminate infection) trial was a cluster-randomised trial of 53 hospitals comparing routine bathing to decolonisation with universal chlorhexidine and targeted nasal mupirocin in non-critical-care units. The trial was done in hospitals affiliated with HCA Healthcare and consisted of a 12-month baseline period from March 1, 2013, to Feb 28, 2014, a 2-month phase-in period from April 1, 2014, to May 31, 2014, and a 21-month intervention period from June 1, 2014, to Feb 29, 2016. Hospitals were randomised and their participating non-critical-care units assigned to either routine care or daily chlorhexidine bathing for all patients plus mupirocin for known methicillin-resistant Staphylococcus aureus (MRSA) carriers. The primary outcome was MRSA or vancomycin-resistant enterococcus clinical cultures attributed to participating units, measured in the unadjusted, intention-to-treat population as the HR for the intervention period versus the baseline period in the decolonisation group versus the HR in the routine care group. Proportional hazards models assessed differences in outcome reductions across groups, accounting for clustering within hospitals. This trial is registered with ClinicalTrials.gov, number NCT02063867.
There were 189 081 patients in the baseline period and 339 902 patients (156 889 patients in the routine care group and 183 013 patients in the decolonisation group) in the intervention period across 194 non-critical-care units in 53 hospitals. For the primary outcome of unit-attributable MRSA-positive or VRE-positive clinical cultures (figure 2), the HR for the intervention period versus the baseline period was 0·79 (0·73–0·87) in the decolonisation group versus 0·87 (95% CI 0·79–0·95) in the routine care group. No difference was seen in the relative HRs (p=0·17). There were 25 (<1%) adverse events, all involving chlorhexidine, among 183 013 patients in units assigned to chlorhexidine, and none were reported for mupirocin.
Decolonisation with universal chlorhexidine bathing and targeted mupirocin for MRSA carriers did not significantly reduce multidrug-resistant organisms in non-critical-care patients.
National Institutes of Health.
Journal Article
Antimicrobial Resistance and Molecular Epidemiology of Staphylococcus aureus Causing Bloodstream Infections at Ruijin Hospital in Shanghai from 2013 to 2018
2020
Staphylococcus aureus
or methicillin-resistant
Staphylococcus aureus
(MRSA) is an important issue associated with significant morbidity and mortality and well known as a predominant pathogen causing bloodstream infection (BSIs) globally. To estimate the antibiotic resistance and molecular characteristics of
S. aureus
causing BSIs in Shanghai, 120
S. aureus
isolates (20 isolates each year) from the patients with
S. aureus
BSIs from 2013 to 2018 were randomly selected and enrolled in this study. Fifty-three (44.2%) MRSA isolates were determined, and no isolate was found resistant to vancomycin, daptomycin, synercid, linezolid and ceftaroline. The toxin genes
tst
,
sec
,
seg
and
sei
were found more frequently among MRSA isolates compared with MSSA isolates (all
P
< 0.0001). Twenty-nine sequence types (STs) were identified, and ST5 (23.3%) was the most common ST, followed by ST398 (11.7%) and ST764 (10.0%). SCC
mec
II (73.6%) was the most frequent SCC
mec
type among MRSA isolates. The dominant clonal complexes (CCs) were CC5 (ST5, ST764, ST965 and ST3066; 36.7%) and the livestock-associated clone CC398 (ST398, 11.7%). MRSA-CC5 was the predominant CC among MRSA isolates (37/53, 69.8%), and CC5-II MRSA was found in 34 isolates accounting for 91.9% (34/37) among CC5 MRSA isolates. In addition, all 29
tst
-positive MRSA isolates were CC5-MRSA as well. Our study provided the properties and genotypes of
S. aureus
causing BSIs at Ruijin Hospital in Shanghai from 2013 to 2018, and might suggest of value clues for the further study insights into pathogenic mechanisms intrinsically referring to the development of human-adapted
S. aureus
clones and their diffusions.
Journal Article
Staphylococcus aureus Community-acquired Pneumonia: Prevalence, Clinical Characteristics, and Outcomes
2016
Background. Prevalence of Staphylococcus aureus community-acquired pneumonia (CAP) and its clinical features remain incompletely understood, complicating empirical selection of antibiotics. Methods. Using a multicenter, prospective surveillance study of adults hospitalized with CAP, we calculated the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) among all CAP episodes. We compared the epidemiologic, radiographic, and clinical characteristics of S. aureus CAP (per respiratory or blood culture) with those of pneumococcal (per respiratory or blood culture or urine antigen) and all-cause non-S. aureus CAP using descriptive statistics. Results. Among 2259 adults hospitalized for CAP, 37 (1.6%) had S. aureus identified, including 15 (0.7%) with MRSA and 22 (1.0%) with MSSA; 115 (5.1%) had Streptococcus pneumoniae. Vancomycin or linezolid was administered to 674 (29.8%) patients within the first 3 days of hospitalization. Chronic hemodialysis use was more common among patients with MRSA (20.0%) than pneumococcal (2.6%) and all-cause non-S. aureus (3.7%) CAP. Otherwise, clinical features at admission were similar, including concurrent influenza infection, hemoptysis, multilobar infiltrates, and prehospital antibiotics. Patients with MRSA CAP had more severe clinical outcomes than those with pneumococcal CAP, including intensive care unit admission (86.7% vs 34.8%) and in-patient mortality (13.3% vs 4.4%). Conclusions. Despite very low prevalence of S. aureus and, specifically, MRSA, nearly one-third of adults hospitalized with CAP received anti-MRSA antibiotics. The clinical presentation of MRSA CAP overlapped substantially with pneumococcal CAP, highlighting the challenge of accurately targeting empirical anti-MRSA antibiotics with currently available clinical tools and the need for new diagnostic strategies.
Journal Article
Decreased expression of femXAB genes and fnbp mediated biofilm pathways in OS-MRSA clinical isolates
by
Appalaraju, Sundarapu Naga
,
Brahma, Umarani
,
Bhandari, Vasundhra
in
38/23
,
631/326/107
,
631/326/22/1434
2019
Methicillin-Resistant
Staphylococcus aureus
(MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of
S. aureus
causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive
S. aureus
(MSSA, n = 48) and oxacillin susceptible
mecA
positive
S. aureus
(OS-MRSA, n = 11) based on oxacillin susceptibility,
mecA
gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of
fem XAB
gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the
fem XAB
genes revealed mutations in
fem
× (K3R, H11N, N18H and I51V) and
fem B
(L410F) genes. The
fem XAB
genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.
Journal Article
Differences in gram-positive bacterial colonization and antimicrobial resistance among children in a high income inequality setting
by
Rezende-Pereira, Gabriel
,
Pinheiro, Marcos Gabriel
,
Cardoso, Claudete Aparecida Araújo
in
Anti-Bacterial Agents - pharmacology
,
Antibacterial agents
,
Antiinfectives and antibacterials
2019
Background
Staphylococcus aureus
and beta-hemolytic streptococci (BHS) diseases disproportionately affect populations in middle/low-income countries. To assess if this disparity is reflected in colonization by these organisms, we compared their colonization frequency among children from different socioeconomic status (SES) communities in a city with high income inequality.
Methods
Between May–August 2014, we collected nasal and throat swabs to investigate
S. aureus
and BHS colonization among children who attended private and public pediatric clinics. Patients were classified as high SES, middle/low SES, and slum residents. We investigated the antimicrobial resistance profile, the SCC
mec
types and the presence of PVL genes among methicillin-resistant
S. aureus
(MRSA). We also examined the antimicrobial resistance profile and serogroups of BHS.
Results
Of 598 children, 221 (37%) were colonized with
S. aureus
, of which 49 (22%) were MRSA. MRSA colonization was higher in middle/low SES (
n
= 18; 14%) compared with high SES (
n
= 17; 6%) and slum (
n
= 14; 8%) residents (
p
= 0.01). All MRSA strains were susceptible to clindamycin, nitrofurantoin, and rifampin. The highest non-susceptibility frequency (42.9%) was observed to erythromycin. SCC
mec
type V was only found in isolates from high SES children; types I and II were found only in middle/low SES children. Ten (20%) MRSA isolates carried PVL genes. Twenty-four (4%) children were BHS carriers. All BHS (
n
= 8) found in high SES children and six (67%) isolates from slum patients belonged to group A. All group B streptococci were from middle/low SES children, corresponding to five (71%) of the seven BHS isolated in this group. BHS isolates were susceptible to all drugs tested.
Conclusions
Children from different SES communities had distinct bacterial colonization profiles, including MRSA carriage. Public health officials/researchers should consider SES when assessing disease transmission and control measures.
Journal Article
Ceftobiprole Versus Daptomycin in Staphylococcus Aureus Bacteremia: A Novel Protocol for a Double-Blind, Phase III trial
2020
Although
is a common cause of bacteremia, treatment options are limited. The need for new therapies is particularly urgent for methicillin-resistant
bacteremia (SAB). Ceftobiprole is an advanced-generation, broad-spectrum cephalosporin with activity against both methicillin-susceptible and -resistant
. This is a Phase III, randomized, double-blind, active-controlled, parallel-group, multicenter, two-part study to establish the efficacy and safety of ceftobiprole compared with daptomycin in the treatment of SAB, including infective endocarditis. Anticipated enrollment is 390 hospitalized adult patients, aged ≥18 years, with confirmed or suspected complicated SAB. The primary end point is overall success rate. Target completion of the study is in the second half of 2021. Clinicaltrials.gov identifier: NCT03138733.
Journal Article
A randomized Phase 2 trial of telavancin versus standard therapy in patients with uncomplicated Staphylococcus aureus bacteremia: the ASSURE study
2014
Background
Staphylococcus aureus
bacteremia is a common infection associated with significant morbidity and mortality. Telavancin is a bactericidal lipoglycopeptide active against Gram-positive pathogens, including methicillin-resistant
S. aureus
(MRSA). We conducted a randomized, double-blind, Phase 2 trial in patients with uncomplicated
S. aureus
bacteremia.
Methods
Patients were randomized to either telavancin or standard therapy (vancomycin or anti-staphylococcal penicillin) for 14 days. Continuation criteria were set to avoid complicated
S. aureus
bacteremia. The primary end point was clinical cure at 84 days.
Results
In total, 60 patients were randomized and 58 received ≥1 study medication dose (all-treated), 31 patients fulfilled inclusion/exclusion and continuation criteria (all-treated target [ATT]) (telavancin 15, standard therapy 16), and 17 patients were clinically evaluable (CE) (telavancin 8, standard therapy 9). Mean age (ATT) was 60 years. Intravenous catheters were the most common source of
S. aureus
bacteremia and ~50% of patients had MRSA. A similar proportion of CE patients were cured in the telavancin (88%) and standard therapy (89%) groups. All patients with MRSA bacteremia were cured and one patient with MSSA bacteremia failed study treatment in each group. Although adverse events (AEs) were more common in the telavancin ATT group (90% vs. 72%), AEs leading to drug discontinuation were similar (7%) in both treatment arms. Potentially clinically significant increases in serum creatinine (≥1.5 mg/dl and at least 50% greater than baseline) were more common in the telavancin group (20% vs. 7%).
Conclusions
This study suggests that telavancin may have utility for treatment of uncomplicated
S. aureus
bacteremia; additional studies are warranted. (Telavancin for Treatment of Uncomplicated
Staphylococcus Aureus
Bacteremia (ASSURE); NCT00062647).
Journal Article
Susceptibility patterns of Staphylococcus aureus biofilms in diabetic foot infections
by
Cavaco-Silva, Patrícia
,
Oliveira, Manuela
,
Mendes, João J.
in
Anti-Bacterial Agents - pharmacology
,
Antibiotics
,
Antimicrobial agents
2016
Background
Foot infections are a major cause of morbidity in people with diabetes and the most common cause of diabetes-related hospitalization and lower extremity amputation.
Staphylococcus aureus
is by far the most frequent species isolated from these infections. In particular, methicillin-resistant
S. aureus
(MRSA) has emerged as a major clinical and epidemiological problem in hospitals. MRSA strains have the ability to be resistant to most β-lactam antibiotics, but also to a wide range of other antimicrobials, making infections difficult to manage and very costly to treat. To date, there are two fifth-generation cephalosporins generally efficacious against MRSA, ceftaroline and ceftobripole, sharing a similar spectrum.
Biofilm formation is one of the most important virulence traits of
S. aureus.
Biofilm growth plays an important role during infection by providing defence against several antagonistic mechanisms. In this study, we analysed the antimicrobial susceptibility patterns of biofilm-producing
S. aureus
strains isolated from diabetic foot infections. The antibiotic minimum inhibitory concentration (MIC) was determined for ten antimicrobial compounds, along with the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC), followed by PCR identification of genetic determinants of biofilm production and antimicrobial resistance.
Results
Results demonstrate that very high concentrations of the most used antibiotics in treating diabetic foot infections (DFI) are required to inhibit
S. aureus
biofilms in vitro, which may explain why monotherapy with these agents frequently fails to eradicate biofilm infections. In fact, biofilms were resistant to antibiotics at concentrations 10–1000 times greater than the ones required to kill free-living or planktonic cells. The only antibiotics able to inhibit biofilm eradication on 50 % of isolates were ceftaroline and gentamicin.
Conclusions
The results suggest that the antibiotic susceptibility patterns cannot be applied to biofilm established infections. Selection of antimicrobial therapy is a critical step in DFI and should aim at overcoming biofilm disease in order to optimize the outcomes of this complex pathology.
Journal Article
Reduced vancomycin susceptibility in Staphylococcus aureus clinical isolates: a spectrum of less investigated uncertainties
by
Khattab, Sally
,
Heiba, Anwar A.
,
Elmaraghy, Nermine
in
Anti-Bacterial Agents - pharmacology
,
Antibiotics
,
Bacterial Proteins - genetics
2024
Background
Staphylococcus aureus
clinical isolates with vancomycin MICs of 2 µg/ml have been associated with vancomycin therapeutic failure and the heterogenous vancomycin-intermediate
S. aureus
(hVISA) phenotype. While carriage of
van
genes has usually been associated with higher level of MIC and frank vancomycin resistance, the unrecognized risk of hetero-resistance is frequently underestimated. Methods used for assessing vancomycin susceptibility have also shown different concordance and variable performance and accessibility in routine clinical diagnostics posing a challenge to inform treatment selection in hospital settings.
Methods
A total of 195 clinical samples were obtained among which 100
S. aureus
isolates were identified. Ninety-six MRSA isolates have been identified using cefoxitin disc and
mec
A gene detection. The
van
A and
van
B genes have been screened for in the studied isolates using conventional PCR amplification. Examination of reduced vancomycin susceptibility has been performed using vancomycin screen agar, Broth Micro Dilution method (BMD), and VITEK2. Blood isolates were screened for hVISA using PAP-AUC method.
Results
Vancomycin screening agar applied to 96 MRSA isolates revealed 16 isolates with reduced vancomycin susceptibility. Further MIC testing revealed that 7 isolates were VISA and only 1 isolate was identified as VRSA using both BMD MIC method and VITEK2. Among 24 tested blood isolates, 4 isolates (16.7%) revealed the hVISA phenotype as identified using PAP-AUC method. Using PCR,
van
A gene was identified in 5
S. aureus
isolates (5%). Three of them were VSSA while the other two isolates were VISA.
Conclusion
In this study, we report the very low prevalence of VRSA among the tested
S. aureus
clinical isolates (1%) and the existence of hVISA phenotype among studied
S. aureus
blood isolates at the rate of 16.7% in our setting. Fifty percent (8/16) of isolates that demonstrated reduced vancomycin susceptibility using vancomycin agar screen tested susceptible using both broth dilution method and VITEK2. These finding together with the concerning silent carriage of
van
A gene among VSSA and VISA (5%) may underly hidden and uninvestigated factors contributing to vancomycin treatment failure that warrant cautious vancomycin prescription.
Journal Article
Development of a human skin commensal microbe for bacteriotherapy of atopic dermatitis and use in a phase 1 randomized clinical trial
2021
Staphylococcus aureus
colonizes patients with atopic dermatitis (AD) and exacerbates disease by promoting inflammation. The present study investigated the safety and mechanisms of action of
Staphylococcus hominis
A9 (
Sh
A9), a bacterium isolated from healthy human skin, as a topical therapy for AD.
Sh
A9 killed
S. aureus
on the skin of mice and inhibited expression of a toxin from
S. aureus
(
psm
α) that promotes inflammation. A first-in-human, phase 1, double-blinded, randomized 1-week trial of topical
Sh
A9 or vehicle on the forearm skin of 54 adults with
S. aureus
-positive AD (NCT03151148) met its primary endpoint of safety, and participants receiving
Sh
A9 had fewer adverse events associated with AD. Eczema severity was not significantly different when evaluated in all participants treated with
Sh
A9 but a significant decrease in
S. aureus
and increased
Sh
A9 DNA were seen and met secondary endpoints. Some
S. aureus
strains on participants were not directly killed by
Sh
A9, but expression of mRNA for
psm
α was inhibited in all strains. Improvement in local eczema severity was suggested by post-hoc analysis of participants with
S. aureus
directly killed by
Sh
A9. These observations demonstrate the safety and potential benefits of bacteriotherapy for AD.
First-in-human test of topical application of a commensal bacterium on skin of individuals with atopic dermatitis reduces colonization by proinflammatory
Staphylococcus aureus
.
Journal Article