Biofilm Formation by Environmental Isolates of Salmonella and Their Sensitivity to Natural Antimicrobials

2016 ◽  
Vol 13 (9) ◽  
pp. 509-516 ◽  
Author(s):  
Shivaramu Keelara ◽  
Siddhartha Thakur ◽  
Jitendra Patel
Keyword(s):  
Biofilm Formation ◽  
Environmental Isolates ◽  
Natural Antimicrobials

The Role of Peganum harmala Ethanolic Extract and Type II Toxin Antitoxin System in Biofilm Formation

Drug Research ◽  
2017 ◽  
Vol 67 (07) ◽  
pp. 385-387
Author(s):  
Nasrin Valizadeh ◽  
Firuzeh Valian ◽  
Nourkhoda Sadeghifard ◽  
Shahriar Karami ◽  
Iraj Pakzad ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Regulatory System ◽  
Ethanolic Extract ◽  
Clinical Isolates ◽  
In Vivo Study ◽  
Type Ii ◽  
Peganum Harmala ◽  
Environmental Isolates

AbstractToxin antitoxin system is a regulatory system that antitoxin inhibits the toxin. We aimed to determine the role of TA loci in biofilm formation in K. pneumoniae clinical and environmental isolates; also inhibition of biofilm formation by Peganum harmala. So, 40 K. pneumoniae clinical and environmental isolates were subjected for PCR to determine the frequency of mazEF, relEB, and mqsRA TA loci. Biofilm formation assay subjected for all isolates. Then, P. harmala was tested against positive biofilm formation strains. Our results demonstrated that relBE TA loci were dominant TA loci; whereas mqsRA TA loci were negative in all isolates. The most environmental isolates showed weak and no biofilm formation while strong and moderate biofilm formation observed in clinical isolates. Biofilm formations by K. pneumoniae in 9 ug/ml concentration were inhibited by P. harmala. In vivo study suggested to be performed to introduce Peganum harmala as anti-biofilm formation in K. pneumoniae.

scholarly journals Phenotypical Comparison of Pseudomonas Aeruginosa Isolated from Human and Veterinary Samples; Impact of Host Adaptation on Infection Pathogenesis

2021 ◽  
Author(s):  
Stefan J. Kaiser ◽  
Annalisa DeRosa ◽  
Christa Ewers ◽  
Frank Günther
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Water Samples ◽  
Biofilm Formation ◽  
Polymorphonuclear Leukocytes ◽  
Environmental Isolates ◽  
Antibiotic Resistant ◽  
Pet Owners ◽  
Zoonotic Risk ◽  
Genetically Determined

Abstract Purpose: Determinants of virulence in Pseudomonas aeruginosa vary strongly depending on its habitat. In this study, we analyzed these alterations depending on the host organism in isolates cultured from canine ears and compared it to clinical extended-spectrum antibiotic-resistant Pseudomonas aeruginosa isolates (XDR), clinical antibiotic-sensitive (non-XDR) from humans and environmental isolates (EI) analyzed during our first study in 2017. Methods: A total of 22 veterinary isolates cultured from canine ears (VET) were examined for spontaneous biofilm formation, stress response in biofilm formation induced by meropenem, in vitro fitness, susceptibility to human serum and polymorphonuclear leukocytes and the genetically determined virulence factors toxA, exoS, exoT, exoU, exoY, nan1, cif, lasA and lasB.Results: We observed significantly elevated spontaneous biofilm formation and serum susceptibility in VET isolates compared to EI and non-XDR isolates as well as significantly decreased in vitro fitness compared to XDR isolates. The VET isolates resembled most the XDR subgroup of isolates previously cultured from blood. Within the environmental isolates, we observed an increase of spontaneous biofilm formation and exoU presence in isolates cultured from community water samples over hospital water samples to pool samples.Conclusions: Considering the distinct differences in some features of the examined VET isolates, a higher degree of phenotypical adaption can be assumed. Increased biofilm formation seems to be a common and characteristic event in isolates adapted to a specific habitat. Therefore amplification of potentially more virulent Pseudomonas aeruginosa strains in domestic animals may lead to elevated zoonotic risk for example for pet owners.

scholarly journals Putative Iron Acquisition Systems in Stenotrophomonas maltophilia

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2048 ◽  
Author(s):  
V. Kalidasan ◽  
Adleen Azman ◽  
Narcisse Joseph ◽  
Suresh Kumar ◽  
Rukman Awang Hamat ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Chemical Nature ◽  
Colorimetric Assay ◽  
Iron Acquisition ◽  
Environmental Isolates ◽  
Iron Starvation ◽  
Receptor System ◽  
Cas Assay ◽  
Significant Expression

Iron has been shown to regulate biofilm formation, oxidative stress response and several pathogenic mechanisms in Stenotrophomonas maltophilia. Thus, the present study is aimed at identifying various iron acquisition systems and iron sources utilized during iron starvation in S. maltophilia. The annotations of the complete genome of strains K279a, R551-3, D457 and JV3 through Rapid Annotations using Subsystems Technology (RAST) revealed two putative subsystems to be involved in iron acquisition: the iron siderophore sensor and receptor system and the heme, hemin uptake and utilization systems/hemin transport system. Screening for these acquisition systems in S. maltophilia showed the presence of all tested functional genes in clinical isolates, but only a few in environmental isolates. NanoString nCounter Elements technology, applied to determine the expression pattern of the genes under iron-depleted condition, showed significant expression for FeSR (6.15-fold), HmuT (12.21-fold), Hup (5.46-fold), ETFb (2.28-fold), TonB (2.03-fold) and Fur (3.30-fold). The isolates, when further screened for the production and chemical nature of siderophores using CAS agar diffusion (CASAD) and Arnows’s colorimetric assay, revealed S. maltophilia to produce catechol-type siderophore. Siderophore production was also tested through liquid CAS assay and was found to be greater in the clinical isolate (30.8%) compared to environmental isolates (4%). Both clinical and environmental isolates utilized hemoglobin, hemin, transferrin and lactoferrin as iron sources. All data put together indicates that S. maltophilia utilizes siderophore-mediated and heme-mediated systems for iron acquisition during iron starvation. These data need to be further confirmed through several knockout studies.

scholarly journals Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

2012 ◽  
Vol 57 (1) ◽  
pp. 382-389 ◽  
Author(s):  
Jorge Meneses Nunes ◽  
Fernando César Bizerra ◽  
Renata Carmona e Ferreira ◽  
Arnaldo Lopes Colombo
Keyword(s):  
Amphotericin B ◽  
Biofilm Formation ◽  
Fungal Pathogens ◽  
Antifungal Susceptibility ◽  
Nitrate Assimilation ◽  
Clinical Isolates ◽  
Its Sequencing ◽  
Environmental Isolates ◽  
Content Type

ABSTRACTRhodotorulaspecies are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmentalRhodotorulaspecies isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44R. mucilaginosaisolates, 2R. glutinisisolates, 2R. minutaisolates, 2R. dairenensisisolates, and 1Rhodosporidium fluvialeisolate. The environmental isolates included 7R. mucilaginosaisolates and 1R. slooffiaeisolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay,R. mucilaginosaandR. minutaexhibited greater biofilm formation ability compared to the otherRhodotorulaspecies; the clinical isolates ofR. mucilaginosashowed greater biofilm formation compared to the environmental isolates (P= 0.04). Amphotericin B showed goodin vitroactivity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identifyRhodotorulaspecies isolates and non-R. mucilaginosaspecies in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment ofRhodotorulainfections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among differentRhodotorulaspecies.

In vitro evaluation of mercury (Hg2+) effects on biofilm formation by clinical and environmental isolates of Klebsiella pneumoniae

2019 ◽  
Vol 169 ◽  
pp. 669-677 ◽  
Author(s):  
Lívia Caroline Alexandre de Araújo ◽  
Antônio Fernando da Purificação-Júnior ◽  
Sivoneide Maria da Silva ◽  
Ana Catarina Souza Lopes ◽  
Dyana Leal Veras ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Environmental Isolates ◽  
In Vitro Evaluation

scholarly journals Clonal Analysis of Clinical and Environmental Pseudomonas aeruginosa Isolates from Meknes Region, Morocco

2017 ◽  
Vol 66 (3) ◽  
pp. 397-400 ◽  
Author(s):  
Itto Maroui ◽  
Abouddihaj Barguigua ◽  
Asmae Aboulkacem ◽  
Hanane Elhafa ◽  
Khadija Ouarrak ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Clonal Analysis ◽  
Pulsed Field Gel Electrophoresis ◽  
Health Concern ◽  
Environmental Isolates ◽  
Public Health Concern ◽  
Close Relationship ◽  
Great Public Health ◽  
Hospital Transmission

From 123 clinical and environmental Pseudomonas aeruginosa isolates, 24 strains were selected for their similar antibioresistance, virulence and biofilm formation profiles, to examine their diversity and occurrence of clones within two hospitals and different natural sites in Meknes (Morocco). Pulsed-field gel electrophoresis, using DraI enzyme, didn’t reveal a close relationship between clinical and environmental isolates nor between strains of the two hospitals. 19 genotypes were obtained, including two virulent environmental clones and three clinical clones virulent and resistant to antibiotics. Intra-hospital transmission of high-risk clones detected, in and between wards, constitutes a great public health concern.

Sign in / Sign up

Export Citation Format

Share Document