Fabrication and optimization of amoxicillin-loaded niosomes: An appropriate strategy to increase antimicrobial and anti-biofilm effects against multidrug-resistant strains of Staphylococcus aureus

2022 ◽  
pp. 1-30
Author(s):  
Pardis Shadvar ◽  
Amir Mirzaie ◽  
Shaghayegh Yazdani
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Resistant Strains

scholarly journals Staphylococcus aureus Infections in Malaysia: A Review of Antimicrobial Resistance and Characteristics of the Clinical Isolates, 1990–2017

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 128 ◽  
Author(s):  
Ainal Mardziah Che Hamzah ◽  
Chew Chieng Yeo ◽  
Suat Moi Puah ◽  
Kek Heng Chua ◽  
Ching Hoong Chew
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Sccmec Type ◽  
Epidemiological Data ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Type Iv ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Comprehensive Surveillance

Staphylococcus aureus is an important nosocomial pathogen and its multidrug resistant strains, particularly methicillin-resistant S. aureus (MRSA), poses a serious threat to public health due to its limited therapeutic options. The increasing MRSA resistance towards vancomycin, which is the current drug of last resort, gives a great challenge to the treatment and management of MRSA infections. While vancomycin resistance among Malaysian MRSA isolates has yet to be documented, a case of vancomycin resistant S. aureus has been reported in our neighboring country, Indonesia. In this review, we present the antimicrobial resistance profiles of S. aureus clinical isolates in Malaysia with data obtained from the Malaysian National Surveillance on Antimicrobial Resistance (NSAR) reports as well as various peer-reviewed published records spanning a period of nearly three decades (1990–2017). We also review the clonal types and characteristics of Malaysian S. aureus isolates, where hospital-associated (HA) MRSA isolates tend to carry staphylococcal cassette chromosome mec (SCCmec) type III and were of sequence type (ST)239, whereas community-associated (CA) isolates are mostly SCCmec type IV/V and ST30. More comprehensive surveillance data that include molecular epidemiological data would enable further in-depth understanding of Malaysian S. aureus isolates.

Intravenous Antibiotics Used in the Treatment of Methicillin-Resistant Staphylococcus Aureus

2015 ◽  
Vol 26 (3) ◽  
pp. 233-243
Author(s):  
Kristine Anne Scordo
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Medical Procedures ◽  
Term Care ◽  
Methicillin Resistant ◽  
Intravenous Antibiotics ◽  
Resistant Strains ◽  
Hospital Acquired

Methicillin-resistant Staphylococcus aureus (MRSA) continues to cause significant morbidity and mortality. Despite advances in medical care, the prevalence of both community-acquired and hospital-acquired MRSA has progressively increased. Community-acquired MRSA typically occurs in patients without recent illness or hospitalization, presents as acute skin and soft tissue infections, and is usually not multidrug resistant. Hospital-acquired MRSA, however, presents in patients recently hospitalized or treated in long-term care settings and in those who have had medical procedures and is usually associated with multidrug-resistant strains. Both types of infections, if not properly treated, have the potential to become invasive. This article discusses current intravenous antibiotics that are available for the empiric treatment of MRSA infections along with a newer phenomenon known as the “seesaw effect.”

scholarly journals Antibiotic Resistance and Virulence Gene Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Healthy Edible Marine Fish

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Justine Fri ◽  
Henry A. Njom ◽  
Collins N. Ateba ◽  
Roland N. Ndip
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Marine Fish ◽  
Control Strategies ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Methicillin Resistant ◽  
Vancomycin Mics ◽  
Resistant Strains ◽  
Mrsa Strains

Thirty-three (33) isolates of methicillin-resistant Staphylococcus aureus (MRSA) from healthy edible marine fish harvested from two aquaculture settings and the Kariega estuary, South Africa, were characterised in this study. The phenotypic antimicrobial susceptibility profiles to 13 antibiotics were determined, and their antibiotic resistance determinants were assessed. A multiplex PCR was used to determine the epidemiological groups based on the type of SCCmec carriage followed by the detection of staphylococcal enterotoxin-encoding genes sea-sed and the Panton Valentine leucocidin gene (pvl). A high antibiotic resistance percentage (67–81%) was observed for Erythromycin, Ampicillin, Rifampicin, and Clindamycin, while maximum susceptibility to Chloramphenicol (100%), Imipenem (100%), and Ciprofloxacin (94%) was recorded. Nineteen (58%) of the MRSA strains had Vancomycin MICs of ≤2 μg/mL, 4 (12%) with MICs ranging from 4–8 μg/mL, and 10 (30%) with values ≥16 μg/mL. Overall, 27 (82%) isolates were multidrug-resistant (MDR) with Erythromycin-Ampicillin-Rifampicin-Clindamycin (E-AMP-RIP-CD) found to be the dominant antibiotic-resistance phenotype observed in 4 isolates. Resistance genes such as tetM, tetA, ermB, blaZ, and femA were detected in two or more resistant strains. A total of 19 (58%) MRSA strains possessed SCCmec types I, II, or III elements, characteristic of healthcare-associated MRSA (HA-MRSA), while 10 (30%) isolates displayed SCCmec type IVc, characteristic of community-associated MRSA (CA-MRSA). Six (18%) of the multidrug-resistant strains of MRSA were enterotoxigenic, harbouring the see, sea, or sec genes. A prevalence of 18% (6/33) was also recorded for the luk-PVL gene. The findings of this study showed that marine fish contained MDR-MRSA strains that harbour SCCmec types, characteristic of either HA-MRSA or CA-MRSA, but with a low prevalence of enterotoxin and pvl genes. Thus, there is a need for continuous monitoring and implementation of better control strategies within the food chain to minimise contamination of fish with MDR-MRSA and the ultimate spread of the bug.

scholarly journals Complete Genome Sequence of Staphylococcus aureus Myophage Maine

2019 ◽  
Vol 8 (40) ◽  
Author(s):  
Russell Moreland ◽  
Abby Korn ◽  
Heather Newkirk ◽  
Mei Liu ◽  
Jason J. Gill ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Human Disease ◽  
Complete Genome ◽  
Multidrug Resistant ◽  
High Similarity ◽  
Promising Alternative ◽  
Content Type ◽  
Resistant Strains

Multidrug-resistant strains of Staphylococcus aureus cause serious human disease worldwide. Bacteriophages offer a promising alternative to traditional antibiotics. Here, we announce the 141,712-bp genome of S. aureus phage Maine. A myophage with 9,019-bp predicted terminal repeats and high similarity to other Staphylococcus phages, Maine falls into the Twort-like group.

scholarly journals Antibacterial Effects of Phage Lysin LysGH15 on Planktonic Cells and Biofilms of Diverse Staphylococci

2018 ◽  
Vol 84 (15) ◽  
Author(s):  
Yufeng Zhang ◽  
Mengjun Cheng ◽  
Hao Zhang ◽  
Jiaxin Dai ◽  
Zhimin Guo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Planktonic Cells ◽  
Content Type ◽  
Resistant Strains ◽  
Staphylococcus Hominis ◽  
Phage Lysin

ABSTRACT Treatment of infections caused by staphylococci has become more difficult because of the emergence of multidrug-resistant strains as well as biofilm formation. In this study, we observed the ability of the phage lysin LysGH15 to eliminate staphylococcal planktonic cells and biofilms formed by Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis. All these strains were sensitive to LysGH15, showing reductions in bacterial counts of approximately 4 log units within 30 min after treatment with 20 μg/ml of LysGH15, and the MICs ranged from 8 μg/ml to 32 μg/ml. LysGH15 efficiently prevented biofilm formation by the four staphylococcal species at a dose of 50 μg/ml. At a higher dose (100 μg/ml), LysGH15 also showed notable disrupting activity against 24-h and 72-h biofilms formed by S. aureus and coagulase-negative species. In the in vivo experiments, a single intraperitoneal injection of LysGH15 (20 μg/mouse) administered 1 h after the injection of S. epidermidis at double the minimum lethal dose was sufficient to protect the mice. The S. epidermidis cell counts were 4 log units lower in the blood and 3 log units lower in the organs of mice 24 h after treatment with LysGH15 than in the untreated control mice. LysGH15 reduced cytokine levels in the blood and improved pathological changes in the organs. The broad antistaphylococcal activity exerted by LysGH15 on planktonic cells and biofilms makes LysGH15 a valuable treatment option for biofilm-related or non-biofilm-related staphylococcal infections. IMPORTANCE Most staphylococcal species are major causes of health care- and community-associated infections. In particular, Staphylococcus aureus is a common and dangerous pathogen, and Staphylococcus epidermidis is a ubiquitous skin commensal and opportunistic pathogen. Treatment of infections caused by staphylococci has become more difficult because of the emergence of multidrug-resistant strains as well as biofilm formation. In this study, we found that all tested S. aureus, S. epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis strains were sensitive to the phage lysin LysGH15 (MICs ranging from 8 to 32 μg/ml). More importantly, LysGH15 not only prevented biofilm formation by these staphylococci but also disrupted 24-h and 72-h biofilms. Furthermore, the in vivo efficacy of LysGH15 was demonstrated in a mouse model of S. epidermidis bacteremia. Thus, LysGH15 exhibits therapeutic potential for treating biofilm-related or non-biofilm-related infections caused by diverse staphylococci.

scholarly journals Vancomycin intermediate resistant Staphylococcus aureus in the nasal cavity of asymptomatic individuals: a potential public health challenge

2020 ◽  
Vol 20 (3) ◽  
pp. 1109-1117
Author(s):  
Morenike Adeoye-Isijola ◽  
Olufunmiso Olajuyigbe ◽  
Kehinde Adebola ◽  
Roger Coopoosamy ◽  
Anthony Afolayan
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Multi Drug Resistance ◽  
Agar Dilution ◽  
Public Health Challenge ◽  
Resistant Strains ◽  
Inhibition Zones ◽  
Asymptomatic Individuals ◽  
Drug Resistant Strains ◽  
Potential Public Health

Background: The potential of transmitting multidrug resistant Staphylococcus aureus from asymptomatic individuals to healthy individuals could constitute a great challenge to antimicrobial therapy. Methods: The antibiograms of the S. aureus from asymptomatic individuals were determined by disk diffusion and agar dilution assay techniques with different antibiotics and vancomycin. Results: Of the 152 S. aureus isolated, (59)38.8% isolates were multi-drug resistant strains. Streptomycin was the most effective and inhibited (135)88.82% of the isolates while ceftazidime inhibited (24)15.8% of the isolates. While (82)54.0% of the isolates inhibited by cefuroxime had resistant colonies within their inhibition zones (Rc) and ofloxacin inhibited (100)65.8% of the isolates without having resistant colonies within the inhibition zones, ceftazidime inhibited (7)4.6% of the isolates with resistant colonies within the inhibition zones. Subjecting the isolates to vancomycin showed that (27)17.8% were resistant to 2 µg/ml, (43)28.3% were resistant to 4 µg/ml and (27)17.8% of the isolates were simultaneously resistant to both concentrations of vancomycin. Although (100)65.8% of the isolates had MARindex ≥0.2, (52)34.2% of the isolates had MARindex ≤ 0.2 and (65)428% of the isolates were considered multidrug resistant strains. Conclusion: The isolation of multi-drug and vancomycin intermediate resistant strains of S. aureus in high percentage, in this study, presents a great threat to clinicians and general populace. The vancomycin intermediate resistant S. aureus (VISA) in asymptomatic individuals could be a critical concern to the therapeutic dilemma to be added to the presence of multi-drug resistance. A more sustainable therapy must be in place to prevent its dissemination or the outbreak of its infection. Keywords: Antibacterial activity; multidrug resistance; VRSA; VISA; vancomycin

Staphylococcus aureus grown in anaerobic conditions exhibit elevated glutamine biosynthesis and biofilm units

2020 ◽  
Author(s):  
V.G. Yugandhar ◽  
M. M. Sunita ◽  
Santhosh Kumar Pasupuleti ◽  
S Subbarayadu ◽  
Abhijit Chaudhary ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Glutamine Synthetase ◽  
Brain Heart Infusion ◽  
Redox Status ◽  
Multidrug Resistant ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Chromosomal Dna ◽  
Resistant Strains ◽  
High Degree

The enormous spread of Staphylococcus aureus infections through biofilms is a major concern in hospital-acquired infections. Biofilm formation by S. aureus on any surface is facilitated by adjusting its redox status. This organism is a facultative anaerobe shifts more towards reductive conditions by enhancing nitrogen metabolism where Glutamine synthesis plays a key role. Glutamine is synthesized by Glutamine synthetase (GS) encoded by the glnA gene was PCR amplified from the chromosomal DNA of Staphylococcus aureus, sequenced (HQ329146.1) and cloned; the pure recombinant GS exhibited KM11.06±0.05mM for Glutamate and 2.4±0.03mM for ATP. The glnA gene sequence showed high degree variability with the human counterpart while it was highly conserved in bacteria. Structural analysis revealed the GS structure of S. aureus showed close homology with other Gram-positive bacteria and exhibited a high degree of variation with E .coli GS. In the present study, we have observed the increased presence of glutamine synthetase activity in multidrug-resistant strains of Staphylococcus aureus with elevated biofilm units grown in brain heart infusion broth among them methicillin-resistant strains of S. aureus LMV3-5 showed higher biofilm units. All these results explain the important role of glutamine biosynthesis with elevated biofilm units in the pathogenesis of S. aureus.

Seasonality Effects on Antibacterial and Antibiotic Potentiating Activity against Multidrug-Resistant Strains of Escherichia coli and Staphylococcus aureus and ATR-FTIR Spectra of Essential Oils from Vitex gardneriana Leaves

2020 ◽  
Vol 77 (12) ◽  
pp. 3969-3977
Author(s):  
Raimundo Luiz Silva Pereira ◽  
Thiago Sampaio de Freitas ◽  
Priscilla Ramos Freitas ◽  
Ana Carolina Justino de Araújo ◽  
Fábia Ferreira Campina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oils ◽  
Multidrug Resistant ◽  
Ftir Spectra ◽  
Resistant Strains ◽  
And Staphylococcus Aureus

scholarly journals Antimicrobial Diterpenes from Azorella Species against Gram-Positive Bacteria

2015 ◽  
Vol 10 (11) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Viviana Donoso ◽  
Mitchell Bacho ◽  
Solange Núñez ◽  
Juana Rovirosa ◽  
Aurelio San-Martín ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Mycobacterium Smegmatis ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Andean Plants

The present study was aimed at evaluating the antibacterial activity of mulinane and azorellane diterpenes isolated from the Andean plants Azorella compacta and A. trifoliolata and semisynthetic derivatives against reference and multidrug-resistant strains. The results revealed that the semisynthetic compound 7-acetoxy-mulin-9,12-diene (5) exhibited antibacterial activity against reference and multidrug-resistant strains of Staphylococcus aureus and moderate antimycobacterial activity against Mycobacterium smegmatis ATCC 14468.

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