Detection and categorization of biofilm-forming Staphylococcus aureus, Viridans streptococcus, Klebsiella pneumoniae, and Escherichia coli isolated from complete denture patients and visualization using scanning electron microscopy

Andonissamy, Leoney; Karthigeyan, Suma; Asharaf, Ali Seyed; Felix, A J W

doi:10.4103/jispcd.jispcd_256_20

Cited by 15 publications

(13 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After biofilm formation, the Gram-stained sample of S. aureus was examined under a bright-field microscope with a 100X objective in an oil immersion medium. Similarly, the samples with the ZnO NPs and tetracycline treatment were examined under a microscope [ 51 ].…”

Section: Methodsmentioning

confidence: 99%

Trichoderma-Mediated ZnO Nanoparticles and Their Antibiofilm and Antibacterial Activities

Shobha

Ashwini

Ghazwani

et al. 2023

JoF

View full text Add to dashboard Cite

Antimicrobial resistance is a major global health concern and one of the gravest challenges to humanity today. Antibiotic resistance has been acquired by certain bacterial strains. As a result, new antibacterial drugs are urgently required to combat resistant microorganisms. Species of Trichoderma are known to produce a wide range of enzymes and secondary metabolites that can be exploited for the synthesis of nanoparticles. In the present study, Trichoderma asperellum was isolated from rhizosphere soil and used for the biosynthesis of ZnO NPs. To examine the antibacterial activity of ZnO NPs against human pathogens, Escherichia coli and Staphylococcus aureus were used. The obtained antibacterial results show that the biosynthesized ZnO NPs were efficient antibacterial agents against the pathogens E. coli and S. aureus, with an inhibition zone of 3–9 mm. The ZnO NPs were also effective in the prevention of S. aureus biofilm formation and adherence. The current work shows that the MIC dosages of ZnO NPs (25, 50, and 75 μg/mL) have effective antibacterial activity and antibiofilm action against S. aureus. As a result, ZnO NPs can be used as a part of combination therapy for drug-resistant S. aureus infections, where biofilm development is critical for disease progression.

show abstract

Section: Methodsmentioning

confidence: 99%

Trichoderma-Mediated ZnO Nanoparticles and Their Antibiofilm and Antibacterial Activities

Shobha

Ashwini

Ghazwani

et al. 2023

JoF

View full text Add to dashboard Cite

show abstract

“…The X-axis represents the K. pneumoniae isolates and the Y-axis represents the optical density at 595nm. The strains were classified based on their biofilm forming abilities according to previous reports (Stepanović et al, 2007; Leoney et al, 2020).…”

Section: Resultsmentioning

confidence: 99%

“…The biofilm forming ability of 12 XDR-K. pneumoniae isolates were assessed by the previously 267 described CV staining method (Stepanović et al, 2007;Leoney et al, 2020). The cut off OD (ODc) 268 obtained was 0.076.…”

mentioning

confidence: 99%

Successfully treating biofilms of extensively drug resistant Klebsiella pneumoniae isolates from hospital patients with N-Acetyl Cysteine

Chauhan

Bhowmik

Rohit

2022

Preprint

View full text Add to dashboard Cite

Klebsiella pneumoniae is one of the leading causes of community and nosocomial infections. Reduced treatment options against extensively drug resistant (XDR) - K. pneumoniae, is a serious concern in hospital settings, and hence, WHO has categorized it as a critical priority pathogen. Biofilm forming ability is a common virulence mechanism amongst K. pneumoniae that is associated with antibiotic tolerance up to 1000X MIC and hence, are difficult to treat. N-acetyl cysteine (NAC) is an FDA approved mucolytic drug used to treat acetaminophen-associated toxicity and obstructive pulmonary diseases. In this study, we assessed antibacterial and antibiofilm activity of NAC against clinical isolates of XDR K. pneumoniae, obtained from Madras Medical Mission Hospital, India. To assess the biofilm eradication ability of NAC, we grew biofilms in 96 well plates and treated the mature biofilms with different concentrations of NAC. We observed that the biofilms of only 3 isolates of XDR K. pneumoniae could be eradicated at a concentration as low as 20mg/ml. Although increasing the concentration of NAC to 80mg/mL could significantly reduce the biofilms of all the isolates up to 4-5 Log, NAC at a concentration of 100 mg/mL successfully eradicated the mature biofilms of all the isolates of XDR K. pneumoniae. This in vitro study demonstrates the potential of NAC as an efficient agent against the biofilms of clinical isolates of XDR-K. pneumoniae and thus provides a promising alternative to antibiotics.

show abstract

“…Biofilm formation capacity was categorized by the following criteria ( Singh et al, 2017 ; Leoney et al, 2020 ):…”

Section: Methodsmentioning

confidence: 99%

Identification and characterization of Bacillus thuringiensis and other Bacillus cereus group isolates from spinach by whole genome sequencing

et al. 2022

View full text Add to dashboard Cite

Bacillus thuringiensis (Bt), used as a biological control agent (BCA), can persist on plants, and from there can be introduced into the final food product. In routine food safety diagnostics, these Bt residues cannot be distinguished from natural populations of Bacillus cereus present in plants and all are enumerated as “presumptive B. cereus.” In this study, information on eventual use of Bt biopesticides, brand, application times and intervals provided by three food processing companies in Belgium, were integrated with quantitative data on presumptive B. cereus measured from fresh to frozen food products. This information together with data on genomic similarity obtained via whole genome sequencing (WGS) and cry gene profiling using a quantitative real-time PCR (qPCR) assay, confirmed that six out of 11 Bt isolates originated from the applied Bt biocontrol products. These identified Bt strains were shown to carry enterotoxin genes (nhe, hbl, cytK-2) and express Hbl enterotoxin in vitro. It was also noted that these Bt biopesticide strains showed no growth at standard refrigeration temperatures and a low or moderate biofilm-forming ability and cytotoxic activity. Our results also showed that the use of Bt as a BCA on spinach plants in the field led to higher residual counts of Bt in spinach (fresh or frozen) in the food supply chain, but the residual counts exceeding at present commonly assumed safety limit of 105 CFU/g was only found in one fresh spinach sample. It is therefore recommended to establish a pre-harvest interval for Bt biopesticide application in the field to lower the likelihood of noncompliance to the generic B. cereus safety limit. Furthermore, WGS was found to be the best way to identify Bt biopesticide isolates at the strain level for foodborne outbreaks and clinical surveillance. The developed qPCR assay for screening on the presence of cry genes in presumptive B. cereus can be applied as a rapid routine test as an amendment to the already existing test on Bt crystal proteins determined via phase-contrast microscopy.

show abstract

Detection and categorization of biofilm-forming Staphylococcus aureus, Viridans streptococcus, Klebsiella pneumoniae, and Escherichia coli isolated from complete denture patients and visualization using scanning electron microscopy

Cited by 15 publications

References 16 publications

Trichoderma-Mediated ZnO Nanoparticles and Their Antibiofilm and Antibacterial Activities

Trichoderma-Mediated ZnO Nanoparticles and Their Antibiofilm and Antibacterial Activities

Successfully treating biofilms of extensively drug resistant Klebsiella pneumoniae isolates from hospital patients with N-Acetyl Cysteine

Identification and characterization of Bacillus thuringiensis and other Bacillus cereus group isolates from spinach by whole genome sequencing

Contact Info

Product

Resources

About