scholarly journals Effect of ZnO nanoparticles on methicillin, vancomycin, linezolid resistance and biofilm formation in Staphylococcus aureus isolates

Author(s):  
Wedad M. Abdelraheem ◽  
Rasha M. M. Khairy ◽  
Alaa I. Zaki ◽  
Shaimaa H. Zaki

Abstract Background Multidrug resistant (MDR) and biofilm producing Staphylococcus aureus strains are usually associated with serious infections. This study aimed to evaluate the antibacterial and antibiofilm-formation effects of zinc oxide nanoparticles (ZnO-NPs) against staphylococcus aureus (S. aureus) isolates. Methods A total of 116 S. aureus isolates were recovered from 250 burn wound samples. The antimicrobial/antibiofilm effects of ZnO-NPs against methicillin, vancomycin and linezolid resistant S. aureus (MRSA, VRSA and LRSA) isolates were examined using phenotypic and genotypic methods. The minimum inhibitory concentration (MIC) of ZnO-NPs was determined by microdilution method. The effects of sub-MIC concentrations of ZnO-NPs on biofilm formation and drug resistance in S. aureus were determined by the microtiter plate method. The change in the expression levels of the biofilm encoding genes and resistance genes in S. aureus isolates after treatment with ZnO-NPs was assessed by real time reverse transcriptase PCR (rt-PCR). Results MICs of ZnO-NPs in S. aureus isolates were (128–2048 µg/ml). The sub-MIC of ZnO-NPs significantly reduced biofilm formation rate (the highest inhibition rate was 76.47% at 1024  µg/ml) and the expression levels of biofilm genes (ica A, ica D and fnb A) with P < 0.001. Moreover, Sub-MIC of ZnO-NPs significantly reduced the rates of MRSA from 81.9 (95 isolates) to 13.30% (15 isolates), VRSA from 33.60 (39 isolates) to 0% and LARSA from 29.30 (34) to 0% as well as the expression levels of resistance genes (mec A, van A and cfr) with P value < 0.001. Conclusion ZnO-NPs can be used as antibiofilm and potent antimicrobial against MRSA, VRSA and LRSA isolates.

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 14
Author(s):  
Dina Auliya Amly ◽  
Puspita Hajardhini ◽  
Alma Linggar Jonarta ◽  
Heribertus Dedy Kusuma Yulianto ◽  
Heni Susilowati

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: The royal jelly concentration of 25% or higher inhibits bacterial growth; however, the subinhibitory concentration increases pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.


2019 ◽  
Vol 22 (4) ◽  
pp. 419-427
Author(s):  
S. Nouri Gharajalar ◽  
M. Onsori

Multidrug resistant Staphylococcus aureus strains are a major health care problem both in humans and animals. In this work we described three multiplex PCR assays for detection of clinically relevant antibiotic resistance genes in S. aureus isolated from dog dental plaques. Thirty dental plaque samples were collected; then cultural, biochemical and molecular tests performed for isolation and identification of S. aureus from samples. The antibiotic susceptibility of the isolates were checked by Kirby Bauer disc diffusion method and the prevalence of antibiotic resistance genes determined using multiplex PCR assay. As a result S. aureus was isolated from 18 dog plaque samples. Fifteen of these isolates were resistant to penicillin. The mecA gene was more prevalent than blaZ among penicillin-resistant bacteria. Ten of the isolates were resistant to tetracycline. The percentage of tetM was higher than tetK among them. Also, 10 of the isolates were resistant to cefazolin among them bla TEM detected in higher rate than blaSHV and blaOXA-1. Hence multiplex PCR assay is a suitable method for detection of antibiotic resistance patterns of S. aureus isolates.


2021 ◽  
Vol 11 (6) ◽  
pp. 1075-1082
Author(s):  
S. Derakhshan ◽  
A. Rezaee ◽  
Sh. Mohammadi

Background and aim. Pseudomonas aeruginosa is considered as a notorious pathogen due to its multidrug resistance and life threatening infections. We investigated the relationship between type III secretion toxins, biofilm formation, and antibiotic resistance among clinical P. aeruginosa isolates. Methods. A total of 70 genetically distinct clinical P. aeruginosa isolates were characterized for antibiotic resistance by disk diffusion assay. Biofilm formation was evaluated by microtiter plate method and presence of four exo genes (exoS, exoU, exoT and exoY) was investigated by PCR. A p-value < 0.05 was regarded statistically significant. Results. The most effective antibiotics were Meropenem and Piperacillin. Multidrug resistance was more prevalent in the ciprofloxacin-resistant isolates than in the susceptible isolates. The most frequently identified exo was exoS (37.1%). Genotype exoS/exoT was found in 4 isolates, while genotype exoU/exoT was not found. Prevalence of exoS was generally higher in the susceptible isolates than in the resistant isolates. A significant association was found between the formation of strong biofilm and resistance to antibiotics (p < 0.05). Prevalence of exoY and exoU was higher in the non-strong biofilm producers compared to the strong biofilm producers. Conclusion. Our study revealed formation of strong biofilm along with antibiotic resistance and the presence of exo genes in P. aeruginosa isolates. Knowledge of virulence gene profiles and biofilm formation may be useful in deciding appropriate treatment.


2008 ◽  
Vol 32 (1) ◽  
pp. 68-72 ◽  
Author(s):  
An Sung Kwon ◽  
Gwang Chul Park ◽  
So Yeon Ryu ◽  
Dong Hoon Lim ◽  
Dong Yoon Lim ◽  
...  

Food Control ◽  
2020 ◽  
Vol 112 ◽  
pp. 107106 ◽  
Author(s):  
Chujun Ou ◽  
Daiqi Shang ◽  
Jingxian Yang ◽  
Bo Chen ◽  
Jiang Chang ◽  
...  

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 667 ◽  
Author(s):  
Marwa I. Abd El-Hamid ◽  
El-sayed Y. El-Naenaeey ◽  
Toka M kandeel ◽  
Wael A. H. Hegazy ◽  
Rasha A. Mosbah ◽  
...  

Multidrug resistant (MDR) methicillin-resistant Staphylococcus aureus (MRSA) is a superbug pathogen that causes serious diseases. One of the main reasons for the lack of the effectiveness of antibiotic therapy against infections caused by this resistant pathogen is the recalcitrant nature of MRSA biofilms, which results in an increasingly serious situation worldwide. Consequently, the development of innovative biofilm inhibitors is urgently needed to control the biofilm formation by this pathogen. In this work, we thus sought to evaluate the biofilm inhibiting ability of some promising antibiofilm agents such as zinc oxide nanoparticles (Zno NPs), proteinase K, and hamamelitannin (HAM) in managing the MRSA biofilms. Different phenotypic and genotypic methods were used to identify the biofilm producing MDR MRSA isolates and the antibiofilm/antimicrobial activities of the used promising agents. Our study demonstrated strong antibiofilm activities of ZnO NPs, proteinase K, and HAM against MRSA biofilms along with their transcriptional modulation of biofilm (intercellular adhesion A, icaA) and quorum sensing (QS) (agr) genes. Interestingly, only ZnO NPs showed a powerful antimicrobial activity against this pathogen. Collectively, we observed overall positive correlations between the biofilm production and the antimicrobial resistance/agr genotypes II and IV. Meanwhile, there was no significant correlation between the toxin genes and the biofilm production. The ZnO NPs were recommended to be used alone as potent antimicrobial and antibiofilm agents against MDR MRSA and their biofilm-associated diseases. On the other hand, proteinase-K and HAM can be co-administrated with other antimicrobial agents to manage such types of infections.


2012 ◽  
Vol 60 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Osman Tel ◽  
Özkan Aslantaş ◽  
Oktay Keskin ◽  
Ebru Yilmaz ◽  
Cemil Demir

In this study,Staphylococcus aureusstrains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried theblaZ and 8 (7.2%) theermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried theicaA andicaD genes but none of them harboured thebapgene. The results demonstrated thatS. aureusisolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of theS. aureusisolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Agathe Boudet ◽  
Pauline Sorlin ◽  
Cassandra Pouget ◽  
Raphaël Chiron ◽  
Jean-Philippe Lavigne ◽  
...  

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.


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