The effect of Frangula alnus extract on biofilm disruption of Staphylococcus aureus MSSA and MRSA strains

2020 ◽  
Author(s):  
Stefana Cvetkovic
Keyword(s):  
Staphylococcus Aureus ◽  
Frangula Alnus ◽  
Biofilm Disruption ◽  
Mrsa Strains

scholarly journals Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine® on MSSA and MRSA Strains

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 869
Author(s):  
Beatriz Müller Nunes Souza ◽  
Juliana Guerra Pinto ◽  
André Henrique Correia Pereira ◽  
Alejandro Guillermo Miñán ◽  
Juliana Ferreira-Strixino
Keyword(s):  
Staphylococcus Aureus ◽  
Photodynamic Therapy ◽  
Antimicrobial Photodynamic Therapy ◽  
Bacterial Inactivation ◽  
Bacterial Reduction ◽  
Complete Inactivation ◽  
Opportunistic Bacteria ◽  
Significant Difference ◽  
Mrsa Strains

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

scholarly journals Antibiotic Resistance, spa Typing and Clonal Analysis of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Blood of Patients Hospitalized in the Czech Republic

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 395
Author(s):  
Katarina Pomorska ◽  
Vladislav Jakubu ◽  
Lucia Malisova ◽  
Marta Fridrichova ◽  
Martin Musilek ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Czech Republic ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
Spa Typing ◽  
The Czech Republic ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Spa Types ◽  
Repeat Pattern

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.

scholarly journals Restoration of Susceptibility of Intracellular Methicillin-Resistant Staphylococcus aureus to β-Lactams: Comparison of Strains, Cells, and Antibiotics

2008 ◽  
Vol 52 (8) ◽  
pp. 2797-2805 ◽  
Author(s):  
Sandrine Lemaire ◽  
Aurélie Olivier ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens ◽  
Peter C. Appelbaum ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dose Response ◽  
Intermediate Phenotype ◽  
Maximal Effect ◽  
Response Curves ◽  
Methicillin Resistant ◽  
Complete Restoration ◽  
Similar Dose ◽  
Dose Response Curves ◽  
Mrsa Strains

ABSTRACT Staphylococcus aureus invades eukaryotic cells. When methicillin-resistant S. aureus (MRSA) ATCC 33591 is phagocytized by human THP-1 macrophages, complete restoration of susceptibility to cloxacillin and meropenem is shown and the strain becomes indistinguishable from MSSA ATCC 25923 due to the acid pH prevailing in phagolysosomes (S. Lemaire et al., Antimicrob. Agents Chemother. 51:1627-1632, 2007). We examined whether this observation can be extended to (i) strains of current clinical and epidemiological interest (three hospital-acquired MRSA [HA-MRSA] strains, two community-acquired MRSA [CA-MRSA] strains, two HA-MRSA strains with the vancomycin-intermediate phenotype, one HA-MRSA strain with the vancomycin-resistant phenotype, and one animal [porcine] MRSA strain), (ii) activated THP-1 cells and nonprofessional phagocytes (keratinocytes, Calu-3 bronchial epithelial cells), and (iii) other β-lactams (imipenem, oxacillin, cefuroxime, cefepime). All strains showed (i) a marked reduction in MICs in broth at pH 5.5 compared with the MIC at pH 7.4 and (ii) sigmoidal dose-response curves with cloxacillin (0.01× to 100× MIC, 24 h of incubation) after phagocytosis by THP-1 macrophages that were indistinguishable from each other and from the dose-response curve for methicillin-susceptible S. aureus (MSSA) ATCC 25923 (relative potency [50% effect], 6.09× MIC [95% confidence interval {CI}, 4.50 to 8.25]; relative efficacy [change in bacterial counts over the original inoculum for an infinitely large cloxacillin concentration, or maximal effect], −0.69 log CFU [95% CI, −0.79 to −0.58]). Similar dose-response curves for cloxacillin were also observed with MSSA ATCC 25923 and MRSA ATCC 33591 after phagocytosis by activated THP-1 macrophages, keratinocytes, and Calu-3 cells. By contrast, there was a lower level of restoration of susceptibility of MRSA ATCC 33591 to cefuroxime and cefepime after phagocytosis by THP-1 macrophages, even when the data were normalized for differences in MICs. We conclude that the restoration of MRSA susceptibility to β-lactams after phagocytosis is independent of the strain and the types of cells but varies between β-lactams.

scholarly journals Genetic Characterization of Methicillin Resistant and Sensitive, Vancomycin Intermediate Staphylococcus aureus Strains Isolated from Different Iranian Hospitals

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Seyed Asghar Havaei ◽  
Amir Azimian ◽  
Hosein Fazeli ◽  
Mahmood Naderi ◽  
Kiarash Ghazvini ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Analysis ◽  
Clinical Samples ◽  
Different Types ◽  
Health Care Policies ◽  
Global Health Care ◽  
Vancomycin Resistant ◽  
Epidemiological Evaluation ◽  
Mrsa Strains

Background. Global concerns have been raised due to upward trend of Vancomycin Intermediate Staphylococcus aureus (VISA) and Vancomycin Resistant Staphylococcus aureus (VRSA) reports which mean casting doubt on the absolute effectiveness of the last line of antibiotic treatment for S. aureus, vancomycin. Hence, epidemiological evaluation can improve global health care policies. Methodology. 171 Isolates of Staphylococcus aureus were collected from different types of clinical samples in selected hospitals in Isfahan, Mashhad, and Tehran, Iran. Then, they were evaluated by agar screening, disk diffusion, and MIC method to determine their resistance to vancomycin and methicillin. The isolated VISA strains were then confirmed with genetic analysis by the evaluation of mecA and vanA genes, SCCmec, agr, and spa type, and also toxin profiles. MLST was also performed. Results and Conclusion. Our data indicated that 67% of isolated S. aureus strains were resistant to methicillin. Furthermore, five isolates (2.9%) had intermediate resistance to vancomycin (VISA). In contrast to usual association of VISA with MRSA strains, we found two isolates of MSSA-VISA. Therefore, our data suggests a probable parallel growing trend of VISA towards MSSA, along with MRSA strains. However, more samples are required to confirm these primarily data. Moreover, genetic analysis of the isolated VISA strains revealed that these strains are endemic Asian clones.

scholarly journals Characterization and Proposed Nomenclature of Epidemic Strains of MRSA in Canada

1999 ◽  
Vol 10 (5) ◽  
pp. 333-336 ◽  
Author(s):  
AE Simor ◽  
D Boyd ◽  
L Louie ◽  
A McGeer ◽  
M Mulvey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
The Past ◽  
Geographic Regions ◽  
Mrsa Strains ◽  
Genotypic Characteristics

The incidence of methicillin-resistantStaphylococcus aureus(MRSA) has been increasing in many Canadian hospitals over the past few years. Some strains may be considered ‘epidemic’, in that they are clinically or epidemiologically significant, and have been identified in patients from multiple hospitals and geographic regions across the country. This paper describes phenotypic and genotypic characteristics of four epidemic MRSA strains in Canada and proposes standardized nomenclature.

scholarly journals Evaluation of Ceftaroline Alone and in Combination against Biofilm-Producing Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Daptomycin and Vancomycin in anIn VitroPharmacokinetic/Pharmacodynamic Model

2015 ◽  
Vol 59 (8) ◽  
pp. 4497-4503 ◽  
Author(s):  
Katie E. Barber ◽  
Jordan R. Smith ◽  
Cortney E. Ireland ◽  
Blaise R. Boles ◽  
Warren E. Rose ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Device ◽  
Bloodstream Infections ◽  
Methicillin Resistant ◽  
Content Type ◽  
Elimination Half ◽  
Antimicrobial Protection ◽  
Mrsa Strains ◽  
Post Hoc

ABSTRACTAnnually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.Staphylococcus aureus, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases inS. aureusisolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistantS. aureus(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in anin vitrobiofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [fCmax], 17.04 mg/liter; elimination half-life [t1/2], 2.66 h), 12 mg/kg of body weight/day of DAP (fCmax, 14.7 mg/liter;t1/2, 8 h), and 450 mg of RIF q12h (fCmax, 3.5 mg/liter;t1/2, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log10CFU/cm2were evaluated by analysis of variance with Tukey'spost hoctest. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log10CFU/cm2reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.

scholarly journals Novel Type of Staphylococcal Cassette Chromosome mec Identified in Community-Acquired Methicillin-Resistant Staphylococcus aureus Strains

2002 ◽  
Vol 46 (4) ◽  
pp. 1147-1152 ◽  
Author(s):  
Xiao Xue Ma ◽  
Teruyo Ito ◽  
Chuntima Tiensasitorn ◽  
Mantana Jamklang ◽  
Piriyaporn Chongtrakool ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance Genes ◽  
Gene Complex ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Class B ◽  
New Type ◽  
Mrsa Strains ◽  
Hospital Acquired ◽  
Staphylococcal Cassette Chromosome

ABSTRACT We identified a new type of staphylococcal cassette chromosome mec (SCCmec) from two community-acquired methicillin-resistant Staphylococcus aureus (MRSA) strains. The novel element, designated type IV SCCmec, had a unique combination of the class B mec gene complex and the type 2 ccr gene complex and was much smaller in size (21 to 24 kb) than previously identified SCCmec elements of hospital-acquired MRSA. Consistent with the strains' susceptibilities to various non-β-lactam antibiotics, the type IV SCCmec was devoid of any antibiotic resistance genes other than the mecA gene.

Multiclonal outbreak of methicillin-resistant Staphylococcus aureus infections on a collegiate football team

2008 ◽  
Vol 137 (1) ◽  
pp. 85-93 ◽  
Author(s):  
A. J. HALL ◽  
D. BIXLER ◽  
L. E. HADDY
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Infection Risk ◽  
Physical Contact ◽  
Soft Tissue Infections ◽  
Risk Of Infection ◽  
Methicillin Resistant ◽  
Football Team ◽  
Mrsa Strains ◽  
Collegiate Football

SUMMARYAn outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) occurred in a college football team in August 2006. Of 109 players on the team roster, 88 (81%) were interviewed during a cohort investigation. Twenty-five cases were identified, six of which were culture-confirmed. Available culture isolates were typed by pulsed-field gel electrophoresis (PFGE), which identified two different MRSA strains associated with the outbreak. Playing positions with the most physical contact (offensive linemen, defensive linemen, and tight ends) had the greatest risk of infection [risk ratio (RR) 5·1, 95% confidence interval (CI) 2·3–11·5. Other risk factors included recent skin trauma (RR 1·9, 95% CI 0·95–3·7), use of therapeutic hydrocollator packs (RR 2·5, 95% CI 1·1–5·7), and miscellaneous training equipment use (RR 2·1, 95% CI 1·1–4·1). The outbreak was successfully controlled through team education and implementation of improved infection-control practices and hygiene policies.

scholarly journals Methicillin-Resistant Staphylococcus aureus Recovered from Healthcare- and Community-Associated Infections in Egypt

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Mohamed Abdel-Maksoud ◽  
Mona El-Shokry ◽  
Ghada Ismail ◽  
Soad Hafez ◽  
Amani El-Kholy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Control ◽  
Continuous Monitoring ◽  
Inhibitory Concentration ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
The Past ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Over Time

Background. Methicillin-resistant Staphylococcus aureus (MRSA) has created significant epidemiological, infection-control, and therapeutic management challenges during the past three decades. Aim. To analyze the pattern of resistance of healthcare- and community-associated MRSA in Egypt and the trend of resistance of HA-MRSA over time (2005–2013). Methods. MRSA isolates were recovered from healthcare-associated (HA) and community-associated (CA) Staphylococcus aureus (S. aureus) infections. They were tested against 11 antimicrobial discs and the minimal inhibitory concentration (MIC) of vancomycin was determined. Inducible clindamycin resistance (iMLSB) was also screened using D-test. Findings. Of 631 S. aureus, MRSA was identified in 343 (76.6%) and 21 (11.5%) of HA and CA S. aureus isolates, respectively. The proportion of HA-MRSA increased significantly from 48.6% in 2005 to 86.8% in 2013 (p value < 0.001). Multidrug resistance (MDR) was observed in 85.8% of HA-MRSA and 48.6% of CA-MRSA. Vancomycin intermediate resistant S. aureus (VISA) was detected in 1.2% of HA-MRSA and none was detected in CA-MRSA. Among HA-MRSA strains, 5.3% showed iMLSB compared to 9.5% among CA-MRSA. Conclusion. The upsurge of the prevalence rates of HA-MRSA over time is alarming and urges for an effective infection control strategy and continuous monitoring of antimicrobial use.

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