scholarly journals Effect of Phage SAvB14 combined with antibiotics on Staphylococcus aureus variant bovis

2021 ◽  
Vol 12 (3) ◽  
pp. 531-536
Author(s):  
Y. V. Horiuk ◽  
M. D. Kukhtyn ◽  
V. V. Horiuk ◽  
V. A. Sytnik ◽  
O. O. Dashkovskyy
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Agent ◽  
Bacterial Infections ◽  
Antibiotic Activity ◽  
Bacterial Isolates ◽  
Antimicrobial Drugs ◽  
Microbial Biofilms ◽  
Combined Application ◽  
Development Of Resistance ◽  
Subsequent Introduction

Because using antimicrobial drugs leads to development of resistance among bacterial isolates, the treatment with antimicrobial drugs in human and veterinary medicine in general should be reduced. Currently, therapeutic use of bacteriophages may be an alternative or addition to the treatment of bacterial infections of animals. The article presents the results of studying the effect of bacteriophage Phage SAvB14 on microbial biofilms of Staphylococcus aureus variant bovis both alone and in complex with antibiotics. For this purpose, we used strain S. aureus var. bovis 1491 f and bacteriophage Phage SAvB14, isolated at dairy farms. The effect of combined application of phage and antibiotics (gentamicin, tetracycline, сeftriaxone and enrofloxacin) were assessed after simultaneous and subsequent introduction of Phage SAvB14 in the dose of 105 plaque-forming units per milliliter (PFU/mL) and corresponding concentrations of antibiotics to 24h biofilms. We determined that of the tested antibiotics, only gentamicin and ceftriazone exerted synergic effects in combinations with Phage SAvB14. Combination treatment using gentamicin and the phage decreased the amount of S. aureus in biofilm by 39.81 times compared with the phage-only treatment. Significant synergic effect was also taken by ceftriaxone – it killed 1.26 times more bacteria in combination with the phage than alone. Other antibiotics did not increase antibiotic activity of the phage. Specifically, 1.11 and 1.26 times more vital cells remained after the actions of tetracycline and enrofloxacin than after the exposure to the bacteriophage only. Therefore, the obtained results indicate that biofilm of S. aureus var. bovis may be eliminated using Phage SAvB14 as an individual antibacterial agent, as well as in complex with antibiotics. However, complex treatment would imply introducing the phage and then antibiotic some time later.

scholarly journals In VitroStudies Indicate a High Resistance Potential for the Lantibiotic Nisin in Staphylococcus aureus and Define a Genetic Basis for Nisin Resistance

2011 ◽  
Vol 55 (5) ◽  
pp. 2362-2368 ◽  
Author(s):  
Katy L. Blake ◽  
Chris P. Randall ◽  
Alex J. O'Neill
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Fold Increase ◽  
Peptide Antibiotics ◽  
Uncharacterized Protein ◽  
Content Type ◽  
Development Of Resistance ◽  
Genes Encoding ◽  
Bacterial Fitness

ABSTRACTLantibiotics such as nisin (NIS) are peptide antibiotics that may have a role in the chemotherapy of bacterial infections. A perceived benefit of lantibiotics for clinical use is their low propensity to select resistance, although detailed resistance studies with relevant bacterial pathogens are lacking. Here we examined the development of resistance to NIS inStaphylococcus aureus, establishing that mutants, including small-colony variants, exhibiting substantial (4- to 32-fold) reductions in NIS susceptibility could be selected readily. Comparative genome sequencing of a single NISrmutant exhibiting a 32-fold increase in NIS MIC revealed the presence of only two mutations, leading to the substitutions V229G in the purine operon repressor, PurR, and A208E in an uncharacterized protein encoded by SAOUHSC_02955. Independently selected NISrmutants also harbored mutations in the genes encoding these products. Reintroduction of these mutations into theS. aureuschromosome alone and in combination revealed that SAOUHSC_02955(A208E) made the primary contribution to the resistance phenotype, conferring up to a 16-fold decrease in NIS susceptibility. Bioinformatic analyses suggested that this gene encodes a sensor histidine kinase, leading us to designate it “nisin susceptibility-associated sensor (nsaS).” Doubling-time determinations and mixed-culture competition assays between NISrand NISsstrains indicated that NIS resistance had little impact on bacterial fitness, and resistance was stable in the absence of selection. The apparent ease with whichS. aureuscan develop and maintain NIS resistancein vitrosuggests that resistance to NIS and other lantibiotics with similar modes of action would arise in the clinic if these agents are employed as chemotherapeutic drugs.

scholarly journals Modulation of the Antibiotic Activity by Extracts fromAmburana cearensisA. C. Smith andAnadenanthera macrocarpa(Benth.) Brenan

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Fernando G. Figueredo ◽  
Emerson O. Ferreira ◽  
Bruno F. F. Lucena ◽  
Cícero M. G. Torres ◽  
Daniel L. Lucetti ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Inhibitory Concentration ◽  
Antibiotic Activity ◽  
Subinhibitory Concentration ◽  
Antimicrobial Drugs ◽  
Ethanol Extracts ◽  
Multiresistant Strains

The aim of this study was to verify the possible interactions between ethanol extracts ofAmburana cearensisA. C. Smith andAnadenanthera macrocarpa(Benth.) Brenan, combined with six antimicrobial drugs against multiresistant strains ofStaphylococcus aureusandEscherichia coliisolated from humans. The antibacterial activity of the extracts was determined using the minimum inhibitory concentration (MIC). The microdilution assay was performed to verify the interactions between the natural products and the antibiotics using a subinhibitory concentration. The activity of amikacin associated with the extract ofAnadenanthera macrocarpaagainst EC 27 was enhanced, demonstrating an MIC reduction from 128 to 4 μg/mL. Among theβ-lactams, no potentiation on its activity was observed, with exception to the antagonism of the natural products with ampicillin againstS. aureus358.

scholarly journals Phenotypic Determination of Biofilm Formation and Acquired Resistance Profile of Clinically-Derived Bacterial Isolates

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Muhammad M Ibrahim ◽  
Abubakar Shettima ◽  
Ibrahim Y. Ngoshe ◽  
Musa Ibn Abbas ◽  
Hauwa S. Bello ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Disease Control ◽  
Acquired Resistance ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Bacterial Isolates ◽  
Antimicrobial Drugs ◽  
Resistance Profile ◽  
Diffusion Technique

Infections caused by biofilm forming bacteria is of major public health concern because of its association with multi-resistance to antimicrobial drugs and host defenses, leading to chronic and recurrent infections. Here, using Congo red agar method, Kirby-bauer disk diffusion technique and the consensus criteria of the European Centre for Disease Control (ECDC) and Centre for Disease Control (CDC), we determined the acquired resistance profile of biofilm producing phenotypes of clinically derived bacteria, classified as Multidrug resistant (MDR), extensively drug resistant (XDR) and Pandrug resistant (PDR). Fifty (50) de-identified bacterial isolates, comprising of five different species (Staphylococcus aureus, Escherichia coli, Proteus spp, Klebsiella pneumoniae and Pseudomonas aeruginosa) were sampled for the study. 64.0% of these isolates were observed to produce biofilms. Isolates recovered from urine samples (50.0%) were the most significant biofilm producers, chief among which was Staphylococcus aureus (15.6%) (X2=0.52; p<.05; P=0.9714). 78.0% of the biofilm producing phenotypes were atleast multidrug resistant (31.4% MDR; 31.4% XDR; 15.7% PDR) (f= 0.40678; df=3; p<.05; P=0.7502). Extreme forms of acquired resistance (XDR and PDR) was more pronounced among biofilm producing strains than the non-biofilm producing strains, and was statistically significant (f=5.0; p=.026336; df=14; p<.05). All Staphylococcus aureus and Pseudomonas aeruginosa isolates were atleast multidrug resistant, with the biofilm producing strains of the latter being completely resistant to Gentamicin and Ciprofloxacin. As such, it can be deduced that resistance to multiple antimicrobial drugs is more pronounced among biofilm producing phenotypes of clinically derived bacterial isolates.

scholarly journals In vitro lytic efficiency of Staphylococcus aureus bacteriophages in bacteria from bovine mastitis: a meta-analysis

2021 ◽  
Vol 51 (10) ◽  
Author(s):  
Bibiana Martins Barasuol ◽  
Valessa Lunkes Ely ◽  
Antônio Francisco Igor Magalhães de Matos ◽  
Luis Antônio Sangioni ◽  
Agueda Castagna de Vargas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Meta Analysis ◽  
Bovine Mastitis ◽  
Lytic Activity ◽  
Random Effects Model ◽  
Bacterial Isolates ◽  
Significant Difference ◽  
Production Animals

ABSTRACT: Bacteriophages have been investigated as alternative to the treatment of bacterial infections, including bovine mastitis, in production animals. In this meta-analysis, we evaluated in vitro efficiency of phages of Staphylococcus aureus against S. aureus, which is involved in the etiology of bovine mastitis. Seventeen studies were included and the bacterial lytic activity was extracted using proportion analysis. The lytic efficiency of phages was obtained in this meta-analysis using a random-effects model [significant difference (P<0.05)]. Forest plots were used to graphically represent the efficiency of phages on bacterial isolates. Most phages (e.g., CS1, DW2, ΦSA011, ΦSA012, ΦSA022, ΦSA023, ΦSA024, ΦSA025, ΦSA037, ΦSA038, ΦSA039, ΦSA041, ΦSA042, ΦSA043, ΦSA044, MSA6, Ufv-aur2 to Ufv-aur11, SAH-1, SPW, vB_SauM_JS25, SaPh1 to SaPh6, SA, SANF, SA2, ΦSA012, ΦSA039, phi11, phiIPLA88, phiIPLA35, phiIPLA-RODI, phiIPLA-C1C, SAJK-IND, vBSP-A1, vBSP-A2, STA1.ST29, EB1.ST11, EB1.ST27, Remus, and ISP) were efficiently lytics or infected most S. aureus isolates, demonstrating 80% (P<0.05) lytic efficiency. The phages SA, SANF and SA2, also demonstrated lytic activity or infected the non-Staphylococcus aureus and Macrococcus caseolyticus isolates. In this meta-analysis, we compared and demonstrated the in vitro efficiency and host range of S. aureus phages. Additionally, the phages represent an alternative to be researched to treat bovine mastitis in dairy cattle caused by the prevalent microorganism, S. aureus.

scholarly journals Inhibition of the ATP Synthase Eliminates the Intrinsic Resistance of Staphylococcus aureus towards Polymyxins

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Martin Vestergaard ◽  
Katrine Nøhr-Meldgaard ◽  
Martin Saxtorph Bojer ◽  
Christina Krogsgård Nielsen ◽  
Rikke Louise Meyer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Atp Synthase ◽  
Bacterial Infections ◽  
Polymyxin B ◽  
Important Class ◽  
Intrinsic Resistance ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Diseases ◽  
Development Of Resistance

ABSTRACT Staphylococcus aureus is intrinsically resistant to polymyxins (polymyxin B and colistin), an important class of cationic antimicrobial peptides used in treatment of Gram-negative bacterial infections. To understand the mechanisms underlying intrinsic polymyxin resistance in S. aureus, we screened the Nebraska Transposon Mutant Library established in S. aureus strain JE2 for increased susceptibility to polymyxin B. Nineteen mutants displayed at least 2-fold reductions in MIC, while the greatest reductions (8-fold) were observed for mutants with inactivation of either graS, graR, vraF, or vraG or the subunits of the ATP synthase (atpA, atpB, atpG, or atpH), which during respiration is the main source of energy. Inactivation of atpA also conferred hypersusceptibility to colistin and the aminoglycoside gentamicin, whereas susceptibilities to nisin, gallidermin, bacitracin, vancomycin, ciprofloxacin, linezolid, daptomycin, and oxacillin were unchanged. ATP synthase activity is known to be inhibited by oligomycin A, and the presence of this compound increased polymyxin B-mediated killing of S. aureus. Our results demonstrate that the ATP synthase contributes to intrinsic resistance of S. aureus towards polymyxins and that inhibition of the ATP synthase sensitizes S. aureus to this group of compounds. These findings show that by modulation of bacterial metabolism, new classes of antibiotics may show efficacy against pathogens towards which they were previously considered inapplicable. In light of the need for new treatment options for infections with serious pathogens like S. aureus, this approach may pave the way for novel applications of existing antibiotics. IMPORTANCE Bacterial pathogens that cause disease in humans remain a serious threat to public health, and antibiotics are still our primary weapon in treating bacterial diseases. The ability to eradicate bacterial infections is critically challenged by development of resistance to all clinically available antibiotics. Polymyxins constitute an important class of antibiotics for treatment of infections caused by Gram-negative pathogens, whereas Gram-positive bacteria remain largely insusceptible towards class of antibiotics. Here we performed a whole-genome screen among nonessential genes for polymyxin intrinsic resistance determinants in Staphylococcus aureus. We found that the ATP synthase is important for polymyxin susceptibility and that inhibition of the ATP synthase sensitizes S. aureus towards polymyxins. Our study provides novel insights into the mechanisms that limit polymyxin activity against S. aureus and provides valuable targets for inhibitors to potentially enable the use of polymyxins against S. aureus and other Gram-positive pathogens. IMPORTANCE Bacterial pathogens that cause disease in humans remain a serious threat to public health, and antibiotics are still our primary weapon in treating bacterial diseases. The ability to eradicate bacterial infections is critically challenged by development of resistance to all clinically available antibiotics. Polymyxins constitute an important class of antibiotics for treatment of infections caused by Gram-negative pathogens, whereas Gram-positive bacteria remain largely insusceptible towards this class of antibiotics. Here we performed a whole-genome screen among nonessential genes for polymyxin intrinsic resistance determinants in Staphylococcus aureus. We found that the ATP synthase is important for polymyxin susceptibility and that inhibition of the ATP synthase sensitizes S. aureus towards polymyxins. Our study provides novel insights into the mechanisms that limit polymyxin activity against S. aureus and provides valuable targets for inhibitors to potentially enable the use of polymyxins against S. aureus and other Gram-positive pathogens.

Antibacterial Activity of Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Kyoung- Sun Seo ◽  
Seong Woo Jin ◽  
Seongkyu Choi ◽  
Kyeong Won Yun
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Agent ◽  
Methanol Extract ◽  
The Other ◽  
Diffusion Method ◽  
E Coli ◽  
Agar Diffusion ◽  
Agar Diffusion Method ◽  
Crude Methanol Extract

The antibacterial activity of three Cupressaceae plants (Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa) was tested against three bacteria using the agar diffusion method. The ether and ethylacetate fraction of crude methanol extract from the three plants showed potent antibacterial activity against the tested microorganisms. The result showed that Staphylococcus aureus revealed the most sensitivity among the tested bacteria. Thujaoccidentalisether fraction and Thujaorientalis hexane fraction exhibited the highest antibacterial activity against Staphylococcus aureus. E. coli was shown the highest MIC values compared to the other two tested bacteria, which indicates the lowest antibacterial activity against the bacterium. This study promises an interesting future for designing a potentially active antibacterial agent from the three Cupressaceae plants.

Garlic Extract (Allium sativum L.) Effectively Inhibits Staphylococcus aureus and Escherichia coli by Invitro Test

2020 ◽  
Vol 2 (2) ◽  
pp. 61-68
Author(s):  
Agnina Listya Anggraini ◽  
Ratih Dewi Dwiyanti ◽  
Anny Thuraidah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Allium Sativum ◽  
Antibacterial Properties ◽  
Herbal Medicines ◽  
Garlic Extract ◽  
Dilution Method ◽  
Initial Stage

Infection is a disease caused by the presence of pathogenic microbes, including Staphylococcus aureus and Escherichia coli. Garlic (Allium sativum L.) has chemical contents such as allicin, alkaloids, flavonoids, saponins, tannins, and steroids, which can function as an antibacterial against Staphylococcus aureus and Escherichia coli. This study aims to determine the antibacterial properties of garlic extract powder against Staphylococcus aureus and Escherichia coli. This research is the initial stage of the development of herbal medicines to treat Staphylococcus aureus and Escherichia coli infections. The antibacterial activity test was carried out by the liquid dilution method. The concentrations used were 30 mg/mL, 40 mg/mL, 50 mg/mL, 60 mg/mL and 70 mg/mL. The results showed that the Minimum Inhibitory Concentration (MIC) against Staphylococcus aureus and Escherichia coli was 40 mg/mL and 50 mg / mL. Minimum Bactericidal Concentration (MBC) results for Staphylococcus aureus and Escherichia coli are 50 mg/mL and 70 mg/mL. Based on the Simple Linear Regression test, the R2 value of Staphylococcus aureus and Escherichia coli is 0.545 and 0.785, so it can be concluded that there is an effect of garlic extract powder on the growth of Staphylococcus aureus and Escherichia coli by 54.5% and 78.5%. Garlic (Allium sativum L.) extract powder has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

STUDIES ON SOME BACTERIAL DISEASES IN OREOCHROMIS NILOTICUS WITH SPECIAL REFERENCES TO TREATMENT

2018 ◽  
pp. 39-47
Author(s):  
Viola Zaki ◽  
Ahmed EL-gamal ◽  
Yasmin Reyad
Keyword(s):  
Oreochromis Niloticus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Histopathological Examination ◽  
Klebsiella Oxytoca ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Tissue Samples ◽  
Hydropic Degeneration ◽  
Total Prevalence

he present research carried out to study the common bacterial infections in Oreochromis niloticus (Nile tilapia) in Manzala area at Dakahlia governorate and possible antimicrobial agents used for treatment. A total number of 400 fish were randomly collected from Manzala private farms at Dakahlia governorate and subjected to the clinical, bacteriological and histopathological examination. The highest prevalence of bacterial isolates during the whole period of examination of naturally infected O.niloticus was recorded for A.hydrophila (22.66%), followed by V.alginolyticus (19.01%), V.parahemolyticus (13.80%), Streptococcus spp. (12.24%), A.caviae (11.72%), V.cholera (10.16%), A.salmonicida (7.55%), while the lowest prevalence was recorded for Klebsiella oxytoca (2.86%). The seasonal highest total prevalence of bacterial isolates from examined naturally infected O. niloticus was recorded in spring (30.21%), followed by autumn (28.39%), then summer (22.40%) and the lowest prevalence was recorded in winter (19.01%). Histopathological findings of the tissue samples which collected from different organs of naturally infected O.niloticus revealed that spleen show marked hemosiderosis and sever hemorrhage, gills showsever congestion of lamellar capillaries with marked aneurysm, necrosis and hemorrhage of lamellar epithelium and liver show sever hydropic degeneration and necrosis of hepatocytes, Ciprofloxacin was the most effective antibiotic against all isolated bacterial strains

Repurposing of auranofin against bacterial infections: An In silico and In vitro study

2020 ◽  
Vol 16 ◽  
Author(s):  
Nidhi Sharma ◽  
Arti Singh ◽  
Ruchika Sharma ◽  
Anoop Kumar
Keyword(s):  
Broad Spectrum ◽  
In Silico ◽  
Antibacterial Agent ◽  
Bacterial Infections ◽  
In Vitro Assays ◽  
Infection Model ◽  
Synergistic Activity ◽  
Bacterial Strains ◽  
Molecular Docking Study

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.

scholarly journals Au–ZnO Conjugated Black Phosphorus as a Near-Infrared Light-Triggering and Recurrence-Suppressing Nanoantibiotic Platform against Staphylococcus aureus

Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 52
Author(s):  
Atanu Naskar ◽  
Sohee Lee ◽  
Kwang-sun Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Near Infrared ◽  
Au Nanoparticles ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Black Phosphorus ◽  
Infrared Light ◽  
Resistant Bacteria ◽  
Near Infrared Light

Antibiotic therapy is the gold standard for bacterial infections treatment. However, the rapid increase in multidrug-resistant (MDR) bacterial infections and its recent use for secondary bacterial infections in many COVID-19 patients has considerably weakened its treatment efficacy. These shortcomings motivated researchers to develop new antibacterial materials, such as nanoparticle-based antibacterial platform with the ability to increase the chances of killing MDR strains and prevent their drug resistance. Herein, we report a new black phosphorus (BP)-based non-damaging near-infrared light-responsive platform conjugated with ZnO and Au nanoparticles as a synergistic antibacterial agent against Staphylococcus aureus species. First, BP nanosheets containing Au nanoparticles were assembled in situ with the ZnO nanoparticles prepared by a low-temperature solution synthesis method. Subsequently, the antibacterial activities of the resulting Au–ZnO–BP nanocomposite against the non-resistant, methicillin-resistant, and erythromycin-resistant S. aureus species were determined, after its photothermal efficacy was assessed. The synthesized nanocomposite exhibited excellent anti-S. aureus activity and good photothermal characteristics. The non-resistant S. aureus species did not produce drug-resistant bacteria after the treatment of multiple consecutive passages under the pressure of the proposed nanoantibiotic, but rapidly developed resistance to erythromycin. This work clearly demonstrates the excellent photothermal antibacterial properties of Au–ZnO–BP nanocomposite against the MDR S. aureus species.

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