scholarly journals Effects of Tormentic Acid and the Extracts from Callistemon citrinus on the Production of Extracellular Proteases by Staphylococcus aureus

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Rumbidzai Mashezha ◽  
Molly Mombeshora ◽  
Stanley Mukanganyama
Keyword(s):  
Staphylococcus Aureus ◽  
Ethanol Extract ◽  
Extracellular Protease ◽  
Protease Production ◽  
Extracellular Proteases ◽  
Therapeutic Molecules ◽  
Antibacterial Susceptibility ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Tormentic Acid

Staphylococcus aureus is among the common nosocomial pathogens. Antibiotics have been used to treat S. aureus infections. However, there has been increased mortality associated with drug-resistant strains of S. aureus. Extracellular proteases have been implicated to be responsible for the transition of S. aureus from an adhesive pathogen to an invasive pathogen. The development of resistant strains has necessitated the search for new sources of drugs. Plants have been traditionally used as sources of therapeutic molecules. The objective of this study was to determine the effect of tormentic acid and the extracts from Callistemon citrinus on the production of extracellular proteases by S. aureus. The broth microdilution antibacterial susceptibility assay was used to determine the antibacterial effects of tormentic acid and the extracts on S. aureus. Both extracts showed a minimum inhibitory concentration (MIC) value of 50 μg/ml. The water : ethanol (50 : 50) and the dichloromethane : methanol (50 : 50) extracts were found to be bactericidal against S. aureus at a concentration of 100 μg/ml and 50 μg/ml, respectively. The effect of tormentic acid and extracts on extracellular protease production was investigated using the protease assay. A zone of proteolytic activity (Pr) was measured as the ratio of the diameter of the colony to the total diameter of colony plus zone of hydrolysis. The extracts reduced the production of extracellular proteases, while tormentic acid completely inhibited the production of extracellular proteases by S. aureus. The Pr value for tormentic acid was found to be 1. The Pr values of the dichloromethane : methanol extract and the water : ethanol extract were 0.92 and 0.84, respectively. In conclusion, tormentic acid was shown to inhibit extracellular protease production; therefore, there is need to explore its use in antivirulence therapy to combat S. aureus infections.

Synergism Between Ethanolic Extract of Propolis (EEP) and Anti-Tuberculosis Drugs on Growth of Mycobacteria

1999 ◽  
Vol 54 (7-8) ◽  
pp. 549-553 ◽  
Author(s):  
Stan Scheller ◽  
Szymon Dworniczak ◽  
Krystian Waldemar-Klimmek ◽  
Marek Rajca ◽  
Anna Tomczyk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synergistic Effect ◽  
Bactericidal Activity ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
Bacterial Activity ◽  
Active Components ◽  
Wild Strains ◽  
Resistant Strains ◽  
Ethanolic Extract Of Propolis

Abstract Ethanolic extract of propolis exerts a strong anti-bacterial activity, in addition to antifungal. antiviral and antiprotozoal properties. In previous studies from these laboratories we have demonstrated that the intensity of the bactericidal activity of EEP is correlated with the virulence of the mycobacteria tested, and that EEP has a synergistic effect with antibiotics on growth of staphylococcus aureus. In the present study we investigated whether the same synergism and correlation exists between EEP and some anti-tuberculosis drugs on tubercu­losis mycobacteria with different degrees of virulence. Six standard strains and 11 wild strains of mycobacteria were exposed for 30 days to EEP, with or without streptomycin, rifamycin, isoniazid or ethambutol. Out of the 17 strains, 8 were resistant to at least two standard antibiotics, and were considered “multi-resistant strains”. The rest were either susceptible or resistant to only one of the antimycobacterial drugs. Antagonism was recorded only in one case, when Staphylococcus aureus were treated with a mixture of EEP and ethambutol, sug­gesting that a chemical bond could have been formed between this anti-tuberculosis anti­ biotic and one of the active components of the ethanol extract of propolis.

scholarly journals Staphylococcus aureus vaccines: Deviating from the carol

2016 ◽  
Vol 213 (9) ◽  
pp. 1645-1653 ◽  
Author(s):  
Dominique Missiakas ◽  
Olaf Schneewind
Keyword(s):  
Staphylococcus Aureus ◽  
Protein A ◽  
Invasive Disease ◽  
Phagocytic Cells ◽  
Subunit Vaccines ◽  
Clinical Endpoints ◽  
Patients At Risk ◽  
Resistant Strains ◽  
Opsonophagocytic Killing ◽  
Drug Resistant Strains

Staphylococcus aureus, a commensal of the human nasopharynx and skin, also causes invasive disease, most frequently skin and soft tissue infections. Invasive disease caused by drug-resistant strains, designated MRSA (methicillin-resistant S. aureus), is associated with failure of antibiotic therapy and elevated mortality. Here we review polysaccharide-conjugate and subunit vaccines that were designed to prevent S. aureus infection in patients at risk of bacteremia or surgical wound infection but failed to reach their clinical endpoints. We also discuss vaccines with ongoing trials for combinations of polysaccharide-conjugates and subunits. S. aureus colonization and invasive disease are not associated with the development of protective immune responses, which is attributable to a large spectrum of immune evasion factors. Two evasive strategies, assembly of protective fibrin shields via coagulases and protein A–mediated B cell superantigen activity, are discussed as possible vaccine targets. Although correlates for protective immunity are not yet known, opsonophagocytic killing of staphylococci by phagocytic cells offers opportunities to establish such criteria.

scholarly journals The Impacts of msaABCR on sarA-Associated Phenotypes Are Different in Divergent Clinical Isolates of Staphylococcus aureus

2019 ◽  
Vol 88 (2) ◽  
Author(s):  
Joseph S. Rom ◽  
Aura M. Ramirez ◽  
Karen E. Beenken ◽  
Gyan S. Sahukhal ◽  
Mohamed O. Elasri ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Clinical Isolates ◽  
Protease Production ◽  
Relative Impact ◽  
Extracellular Proteases ◽  
Content Type ◽  
The Impact

ABSTRACT The staphylococcal accessory regulator (sarA) plays an important role in Staphylococcus aureus infections, including osteomyelitis, and the msaABCR operon has been implicated as an important factor in modulating expression of sarA. Thus, we investigated the contribution of msaABCR to sarA-associated phenotypes in the S. aureus clinical isolates LAC and UAMS-1. Mutation of msaABCR resulted in reduced production of SarA and a reduced capacity to form a biofilm in both strains. Biofilm formation was enhanced in a LAC msa mutant by restoring the production of SarA, but this was not true in a UAMS-1 msa mutant. Similarly, extracellular protease production was increased in a LAC msa mutant but not a UAMS-1 msa mutant. This difference was reflected in the accumulation and distribution of secreted virulence factors and in the impact of extracellular proteases on biofilm formation in a LAC msa mutant. Most importantly, it was reflected in the relative impact of mutating msa as assessed in a murine osteomyelitis model, which had a significant impact in LAC but not in UAMS-1. In contrast, mutation of sarA had a greater impact on all of these in vitro and in vivo phenotypes than mutation of msaABCR, and it did so in both LAC and UAMS-1. These results suggest that, at least in osteomyelitis, it would be therapeutically preferable to target sarA rather than msaABCR to achieve the desired clinical result, particularly in the context of divergent clinical isolates of S. aureus.

scholarly journals Synergistic Antimycobacterial Actions ofKnowltonia vesicatoria(L.f) Sims

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Antoinette Labuschagné ◽  
Ahmed A. Hussein ◽  
Benjamín Rodríguez ◽  
Namrita Lall
Keyword(s):  
South African ◽  
Inhibitory Concentration ◽  
Ethanol Extract ◽  
Antimycobacterial Activity ◽  
First Report ◽  
Pelargonium Sidoides ◽  
Resistant Strains ◽  
African Plants ◽  
Drug Resistant Strains ◽  
Euclea Natalensis

Euclea natalensisA.DC.,Knowltonia vesicatoria(L.f) Sims, andPelargonium sidoidesDC. are South African plants traditionally used to treat tuberculosis. Extracts from these plants were used in combination with isoniazid (INH) to investigate the possibility of synergy with respect to antimycobacterial activity. The ethanol extract ofK. vesicatoriawas subjected to fractionation to identify the active compounds. The activity of theKnowltoniaextract remained superior to the fractions with a minimum inhibitory concentration (MIC) of 625.0 μg/mL againstMycobacterium smegmatisand an MIC of 50.00 μg/mL againstM. tuberculosis. TheK. vesicatoriaextract was tested against two different drug-resistant strains ofM. tuberculosis, which resulted in an MIC of 50.00 μg/mL on both strains. The combination ofK. vesicatoriawith INH exhibited the best synergistic antimycobacterial activity with a fractional inhibitory concentration index of 0.25 (a combined concentration of 6.28 μg/mL). A fifty percent inhibitory concentration of this combination against U937 cells was 121.0 μg/mL. Two compounds, stigmasta-5,23-dien-3-ol (1) and 5-(hydroxymethyl)furan-2(5H)-one (2), were isolated fromK. vesicatoriaas the first report of isolation for both compounds from this plant and the first report of antimycobacterial activity. Compound (1) was active against drug-sensitiveM. tuberculosiswith an MIC of 50.00 μg/mL.

scholarly journals Studies on the effects of 3-acetyl-4"-isovaleryltylosin against multiple-drug resistant strains of Staphylococcus aureus.

1981 ◽  
Vol 34 (3) ◽  
pp. 305-312 ◽  
Author(s):  
MASAMI TSUCHIYA ◽  
KAYOKO SUZUKAKE ◽  
MAKOTO HORI ◽  
TSUTOMU SAWA ◽  
TOMIO TAKEUCHI ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Multiple Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

scholarly journals Recombinant ESAT-6-Like Proteins Provoke Protective Immune Responses against Invasive Staphylococcus aureus Disease in a Murine Model

2014 ◽  
Vol 83 (1) ◽  
pp. 339-345 ◽  
Author(s):  
Bao Zhong Zhang ◽  
Yan Hong Hua ◽  
Bin Yu ◽  
Candy Choi Yi Lau ◽  
Jian Piao Cai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Responses ◽  
Survival Rates ◽  
Passive Immunization ◽  
Health Concern ◽  
Drug Resistant ◽  
Public Health Concern ◽  
Content Type ◽  
Resistant Strains ◽  
Drug Resistant Strains

Staphylococcus aureusis a common pathogen found in the community and in hospitals. Most notably, methicillin-resistantS. aureusis resistant to many antibiotics, which is a growing public health concern. The emergence of drug-resistant strains has prompted the search for alternative treatments, such as immunotherapeutic approaches. To date, most clinical trials of vaccines or of passive immunization againstS. aureushave ended in failure. In this study, we investigated two ESAT-6-like proteins secreted byS. aureus,S. aureusEsxA (SaEsxA) and SaEsxB, as possible targets for a vaccine. Mice vaccinated with these purified proteins elicited high titers of anti-SaEsxA and anti-SaEsxB antibodies, but these antibodies could not preventS. aureusinfection. On the other hand, recombinant SaEsxA (rSaEsxA) and rSaEsxB could induce Th1- and Th17-biased immune responses in mice. Mice immunized with rSaEsxA and rSaEsxB had significantly improved survival rates when challenged withS. aureuscompared with the controls. These findings indicate that SaEsxA and SaEsxB are two promising Th1 and Th17 candidate antigens which could be developed into multivalent and serotype-independent vaccines againstS. aureusinfection.

scholarly journals Study of bacterial pathogens causing chronic suppurative otitis media and the antibiotic susceptibility pattern of the isolates at a tertiary care centre in Kochi

2020 ◽  
Vol 6 (4) ◽  
pp. 714
Author(s):  
Geetha Nair ◽  
Tanya Tonny Mampilly ◽  
Bindhu Vasudevan ◽  
J. Lancy
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Otitis Media ◽  
Tertiary Care ◽  
Drug Resistant ◽  
Care Centre ◽  
Tertiary Care Centre ◽  
Suppurative Otitis Media ◽  
Resistant Strains ◽  
Drug Resistant Strains

<p class="abstract"><strong>Background:</strong> Chronic suppurative otitis media (CSOM) is defined as chronic inflammation of middle ear and mastoid cavity presenting with recurrent ear discharges through a tympanic membrane perforation. Complications of CSOM were frequent in pre-antibiotic era. Injudicious use of antibiotics led to the emergence of multi-drug resistant strains and complications in return. To isolate the organisms associated with CSOM in a tertiary care centre and to detect their antibiogram.</p><p class="abstract"><strong>Methods:</strong> In this clinical, prospective, cross sectional study, a total of 100 patients clinically diagnosed with CSOM were enrolled from January to December 2019 (1 year).  </p><p class="abstract"><strong>Results:</strong> Of the 100 samples collected, predominant bacteria were isolated in 58 patients (58%). The most common isolate was <em>Pseudomonas aeruginosa</em> (29 isolates) followed by <em>Staphylococcus aureus</em> (24), <em>Klebsiella</em> species (3) and 1 isolate each of <em>Pneumococci</em> and <em>Acinetobacter</em> species. Among the 29 isolates of <em>Pseudomonas aeruginosa</em>, 8 (28%) were multidrug resistant. Sensitivity was 100% to imipenem followed by 97% to meropenem,79% to gentamicin, 76% to amikacin, 66% to ciprofloxacin, 41% to piperacillin tazobactam and 17% to ceftazidime. Of the 24 isolates of <em>Staphylococcus aureus</em>, 4 (16%) were methicillin resistant <em>Staphylococcus aureus</em> (MRSA).</p><p class="abstract"><strong>Conclusions:</strong> Pseudomonas aeruginosa was the most common isolate, of which 28% were multi drug resistant. This calls for the judicious use of antibiotics and alternative measures for treatment of drug resistant strains. Formulating an antibiotic policy based on the local antibiogram can help in preventing the emergence and spread of resistant pathogens.</p>

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

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