The pathogenesis and control of Staphylococcus aureus-induced mastitis: study models in the mouse

2005 ◽  
Vol 7 (3) ◽  
pp. 560-568 ◽  
Author(s):  
Eric Brouillette ◽  
François Malouin
Keyword(s):  
Staphylococcus Aureus ◽  
And Control

Properties and control of cold-induced small colony variants of Staphylococcus aureus

2020 ◽  
pp. 100874
Author(s):  
Jiaju Qiao ◽  
Mengjiao Zhu ◽  
Yun Fan ◽  
Zhaoxin Lu ◽  
Fengxia Lv ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Small Colony Variants ◽  
Small Colony ◽  
And Control

scholarly journals Real-Time In Vivo Bioluminescent Imaging for Evaluating the Efficacy of Antibiotics in a Rat Staphylococcus aureus Endocarditis Model

2005 ◽  
Vol 49 (1) ◽  
pp. 380-387 ◽  
Author(s):  
Yan Q. Xiong ◽  
Julie Willard ◽  
Jagath L. Kadurugamuwa ◽  
Jun Yu ◽  
Kevin P. Francis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Imaging System ◽  
Bioluminescent Imaging ◽  
Vancomycin Therapy ◽  
Treatment Groups ◽  
Highly Sensitive ◽  
Relevant Animal Model ◽  
And Control

ABSTRACT Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bioluminescently engineered, biofilm-positive S. aureus strain was used to evaluate real-time antibiotic efficacy directly. This strain was vancomycin and cefazolin susceptible but gentamicin resistant. Bioluminescence was detected and quantified daily in antibiotic-treated and control animals with IE, using a highly sensitive in vivo imaging system (IVIS). Persistent and increasing cardiac bioluminescent signals (BLS) were observed in untreated animals. Three days of vancomycin therapy caused significant reductions in both cardiac BLS (>10-fold versus control) and S. aureus densities in cardiac vegetations (P < 0.005 versus control). However, 3 days after discontinuation of vancomycin therapy, a greater than threefold increase in cardiac BLS was observed, indicating relapsing IE (which was confirmed by quantitative culture). Cefazolin resulted in modest decreases in cardiac BLS and bacterial densities. These microbiologic and cardiac BLS differences during therapy correlated with a longer time-above-MIC for vancomycin (>12 h) than for cefazolin (∼4 h). Gentamicin caused neither a reduction in cardiac S. aureus densities nor a reduction in BLS. There were significant correlations between cardiac BLS and S. aureus densities in vegetations in all treatment groups. These data suggest that bioluminescent imaging provides a substantial advance in the real-time monitoring of the efficacy of therapy of invasive S. aureus infections in live animals.

scholarly journals Perfil Epidemiológico dos Isolamentos dos Microrganismos ‘Problema’

2019 ◽  
Vol 32 (9) ◽  
pp. 600
Author(s):  
Pedro Atilano Carvalho ◽  
Ana Monteiro ◽  
Bruno Almeida ◽  
Filomena Horta Correia ◽  
Vera Resende ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Beta Lactamase ◽  
Drug Resistant ◽  
Streptococcus Pneumonia ◽  
Extended Spectrum Beta Lactamase ◽  
The North ◽  
Male Patients ◽  
Epidemiological Profile ◽  
Healthcare Associated ◽  
And Control

Introduction: Infections are a major problem and the presence of drug-resistant microorganisms has significant clinical and economic impact. The present study aims to evaluate the epidemiological profile of “problem” microorganisms isolated in a hospital in the north of Portugal.Material and Methods: All isolated microorganisms were analyzed, between January 2014 and June 2015. Data obtained was then processed using statistical software.Results: We analyzed 8146 microbiological isolations and found a prevalence of 23% of ‘problem’ microorganisms (in descending order of frequency: Enterococcus, Pseudomonas, Staphylococcus aureus e Streptococcus pneumonia), 57.55% of which isolated in male patients. The most frequent mechanism of drug resistance for the overall sample was the production of extended-spectrum beta-lactamase, and resistance to oxacillin for ‘problem’ microorganisms.Discussion: In this sample, we observed a much higher prevalence of ‘problem’ microorganisms than that reported in other countries, which shows the need of improvement of surveillance mechanisms and treatment of these cases. Microorganisms that showed higher resistance were Staphylococcus aureus (resistant to oxacillin) and Enterococcus (resistant to vancomycin). Those were isolated in patients with a higher mean age compared to non-resistant microorganisms. Most of these microorganisms were isolated in hospitalized patients or intermediate and intensive care units, what relates them with healthcare associated infections.Conclusion: The prevalence of infection by ‘problem’ microorganisms during the studied period was 23%. The detection and control of the spread of these microorganisms are paramount due to its impact on health costs, morbidity and survival of patients.

Barrier and Antibacterial Properties of 2-Octyl Cyanoacrylate-Derived Wound Treatment Films

2003 ◽  
Vol 7 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Patricia M. Mertz ◽  
Stephen C. Davis ◽  
Alejandro L. Cazzaniga ◽  
Anna Drosou ◽  
William H. Eaglstein
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Contamination ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bacterial Invasion ◽  
Wound Treatment ◽  
Antimicrobial Study ◽  
And Control ◽  
Number Of Bacteria

Background: Besides enhancing healing, an ideal dressing should prevent invasion of pathogens and control the number of bacteria already present in the wounds. Objective: To evaluate the barrier and antimicrobial properties of a cyanoacrylate-based bandage (LAB) against Staphylococcus aureus or Pseudomonas aeruginosa on partial thickness wounds in swines. Methods: Barrier study: Bacteria were inoculated over test materials (LAB, standard bandage, air-exposed) that were placed over wounds. The bacteria from wounds were quantitated at 24, 48, and 72 hours postinoculation. Antimicrobial study: Wounds inoculated with bacteria were covered with LAB, standard bandage, or hydrocolloid bandage or left air-exposed. The bacteria recovered from wounds were quantitated at 24 and 72 hours after treatment. Results: Barrier study: No bacteria were recovered from LAB-treated wounds. Antimicrobial study: LAB reduced the number of inoculated bacteria in comparison to all other groups. Conclusion: LAB is effective in protecting wounds from external bacterial invasion and reducing bacterial contamination.

scholarly journals Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) colonisation and infection among livestock workers and veterinarians: a systematic review and meta-analysis

2020 ◽  
pp. oemed-2020-106418
Author(s):  
Chen Chen ◽  
Felicia Wu
Keyword(s):  
Staphylococcus Aureus ◽  
Publication Bias ◽  
Meta Analysis ◽  
Health Concern ◽  
Control Groups ◽  
Methicillin Resistant ◽  
Preventive Practices ◽  
Swine Workers ◽  
Registration Number ◽  
And Control

ObjectivesMethicillin-resistant Staphylococcus aureus (MRSA) is an increasing public health concern worldwide. The objective of this study was to calculate a summary odds ratio (OR) of livestock-associated MRSA colonisation and infection in humans, and to determine specific risk factors in livestock production contributing to MRSA colonisation.MethodsWe screened PubMed and Embase for studies published from 2005 to 2019 inclusive, reporting livestock-associated (LA)-MRSA colonisation and infection among livestock workers/veterinarians, their families, and community members not regularly exposed to livestock. The primary outcome of interest was the OR of LA-MRSA colonisation comparing exposed and control groups. Quality was assessed according to the Newcastle-Ottawa quality assessment scale. A meta-analysis using a random-effects model was conducted to calculate a pooled OR. The heterogeneity in the meta-analysis was assessed using the I² method, and publication bias was evaluated using funnel plots.ResultsA total of 3490 studies were identified by the search, with 37 studies including 53 matched exposed-control groups and 14 038 participants eligible for the meta-analysis. The pooled OR for LA-MRSA among livestock workers and veterinarians is 9.80 (95% CI 6.89 to 13.95; p=0.000; I2=73.4), with no significant publication bias (Egger’s p=0.66). The OR for swine workers was highest at 15.41 (95% CI 9.24 to 25.69), followed by cattle workers (11.62, 95% CI 4.60 to 29.36), veterinarians (7.63, 95% CI 3.10 to 18.74), horse workers (7.45, 95% CI 2.39 to 23.25), livestock workers (5.86, 95% CI 1.14 to 30.16), poultry workers (5.70, 95% CI 1.70 19.11), and industrial slaughterhouse workers (4.69, 95% CI 1.10 to 20.0).ConclusionsLivestock workers, particularly swine farmers, are at significantly higher risk for LA-MRSA colonisation and subsequent infection. These results support the need for preventive practices to reduce LA-MRSA risk among those who handle and treat livestock.Trial registration numberCRD42019120403.

scholarly journals Clearance of Staphylococcus aureus from In Vivo Models of Chronic Infection by Immunization Requires Both Planktonic and Biofilm Antigens

2019 ◽  
Vol 88 (1) ◽  
Author(s):  
Janette M. Harro ◽  
Yvonne Achermann ◽  
Jeffrey A. Freiberg ◽  
Devon L. Allison ◽  
Kristen J. Brao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Protective Efficacy ◽  
Passive Immunization ◽  
Quadrivalent Vaccine ◽  
Bacterial Populations ◽  
In Vivo Models ◽  
Content Type ◽  
Pentavalent Vaccine ◽  
And Control

ABSTRACT Staphylococcus aureus is a causative agent of chronic biofilm-associated infections that are recalcitrant to resolution by the immune system or antibiotics. To combat these infections, an antistaphylococcal, biofilm-specific quadrivalent vaccine against an osteomyelitis model in rabbits has previously been developed and shown to be effective at eliminating biofilm-embedded bacterial populations. However, the addition of antibiotics was required to eradicate remaining planktonic populations. In this study, a planktonic upregulated antigen was combined with the quadrivalent vaccine to remove the need for antibiotic therapy. Immunization with this pentavalent vaccine followed by intraperitoneal challenge of BALB/c mice with S. aureus resulted in 16.7% and 91.7% mortality in pentavalent vaccine and control groups, respectively (P < 0.001). Complete bacterial elimination was found in 66.7% of the pentavalent cohort, while only 8.3% of the control animals cleared the infection (P < 0.05). Further protective efficacy was observed in immunized rabbits following intramedullary challenge with S. aureus, where 62.5% of the pentavalent cohort completely cleared the infection, versus none of the control animals (P < 0.05). Passive immunization of BALB/c mice with serum IgG against the vaccine antigens prior to intraperitoneal challenge with S. aureus prevented mortality in 100% of mice and eliminated bacteria in 33.3% of the challenged mice. These results demonstrate that targeting both the planktonic and biofilm stages with the pentavalent vaccine or the IgG elicited by immunization can effectively protect against S. aureus infection.

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