scholarly journals Влияние цефтриаксона и тетрациклина на формирование биопленки штаммами Staphylococcus epidermidis

2014 ◽  
Vol 5 (1) ◽  
pp. 7-11
Author(s):  
O. I. Sidashenko ◽  
O. S. Voronkova ◽  
Y. A. Sirokvasha ◽  
A. I. Vinnikov
Keyword(s):  
Biofilm Formation ◽  
Film Formation ◽  
Cell Number ◽  
Biological Properties ◽  
Biochemical Properties ◽  
Clinical Strain ◽  
Biofilm Growth ◽  
Minimal Inhibitory Concentrations ◽  
Film Forming ◽  
Physiological And Biochemical

122 strains of staphylococci were identified. Among the examined 122 clinical strains of staphylococci, 67 strains belonged to coagulase-positive, and 55 strains to the coagulase-negative ones. According to the study of physiological and biochemical properties, it was found that 37 strains (30.3%) belonged to S. epidermidis species. One of the biological properties of many bacteria is the ability to film formation and these strains attract special attention, since it is known that the film antibiotic resistance is higher than in planktonic cultures. It was determined that 20 strains of those under study were film-forming, 17 strains – non-biofilm forming ones. The film was formed during three days, and settled to the bottom of the plate holes. The clinical (Cl) strain of S. epidermidis was sensitive to ceftriaxone and tetracicline. The control (C) strains of S. epidermidis were sensitive to ceftriaxone, tetracycline and sizomicine. The study of biofilm growth for 2, 3 and 4 days of incubation was carried out. The maximum rate of biofilm S. epidermidis C was observed during 2–3 days; there is the most intense increase of cells number from 5.2 × 108 CFU/ml, for S. epidermidis Cl to 5.6 × 108 CFU/ml. The effect of ceftriaxone and tetracycline on biofilm formation by 2 investigation strains of S. epidermidis was found. We determined differences in minimal inhibitory concentrations (MIC) for planktonic cultures and biofilm of strains under study. It was established that MIC antibiotics inhibited the growth of planktonic cultures on average 2 times lower compared to the MIC which inhibited the biofilm formation. MIC for planktonic culture of S. epidermidis Cl defined for ceftriaxone was equal to 10 mg/ml, and for tetracycline – 1 mg/ml. MIC of ceftriaxone for the control strain was equal to 12 mg/ml, MIC of tetracycline – 0.7 mg/ml. MIC values for dynamics biofilm formation of S. epidermidis Cl strain on the plater were as follows: to ceftriaxone – 20 mg/ml and for tetracycline – 2 mg/ml, MIC of ceftriaxone for S. epidermidis C strain – 24 mg/ml, MIC of tetracycline – 1.5 mg/ml. The effect of ceftriaxone and tetracycline was defined to the larger extent, than MIC for biofilm-forming on the plate (10, 50 and 100 times). More effective action of tetracycline was shown for 1- and 2-daily biofilm cultures of S. epidermidis clinical strain. Adding tetracycline concentration of 20 mg/ml in the culture medium of the 1-day biofilm of S. epidermidis Cl strain reduced the cell number of biofilm formation 590 times, increasing concentrations of tetracycline to 100 mg/ml and added to the 1-day biofilm of the clinical strain reduced the number of bacterial cell 4400 times compared with control. 

scholarly journals Antimicrobial Resistance in Pseudomonas aeruginosa Biofilms

2021 ◽  
Author(s):  
Dhara Patel ◽  
Palash Sen ◽  
Yin Hlaing ◽  
Michael Boadu ◽  
Bassam Saadeh ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Growth Inhibition ◽  
Biofilm Formation ◽  
Broth Microdilution ◽  
Planktonic Cells ◽  
Biofilm Growth ◽  
Minimal Inhibitory Concentrations ◽  
Dose Dependent

Pseudomonas aeruginosa (PA) is part of a group of common nosocomial pathogens that exhibit multidrug resistance, thus proving to be a significant threat to healthcare. This study analyzes the ability of four commonly used antibiotics to observe eradication of the PA biofilm growth. Ceftazidime (CAZ), Tobramycin (TOB), Ofloxacin (OFLX), Meropenem (MEM), were tested against overnight cultures of PA strain PA01. The minimal inhibitory concentrations (MIC) of planktonic cells for all the four antibiotics were determined using broth microdilution while the minimal bactericidal concentrations (MBCs) were determined by colony count after antibiotic treatment and regrowth. Biofilm growth inhibition was performed by treating cells with antibiotic at the time of inoculation while eradication was determined by adding antibiotics 24 hours after inoculation, allowing mature biofilm formation, followed by the measurement of absorbance. PA planktonic cells exhibited the highest susceptibility to MEM compared to overnight grown PA biofilm which demonstrated resistance to CAZ, complete sensitivity to ofloxacin, and minimal sensitivity to TOB and MEM. PA biofilm displayed dose-dependent sensitivity to TOB, MEM and OFLX, and a significant level of resistance to CAZ during the inhibition phase. However, in the eradication phase, PA showed significant resistance to TOB followed by CAZ while PA biofilm showed sensitivity at higher concentrations of MEM. Our study exhibits that PA strain PA01 is resistant to ceftazidime in both planktonic and biofilm phases. While ofloxacin proved to be the most effective even at lower concentrations when compared with other antibiotics, tobramycin was most effective at higher concentrations for eradicating and inhibiting PA biofilms.

scholarly journals STUDY OF THE BIOLOGICAL AND DESTRUCTIVE ACTIVITY OF HETEROTROPHIC MICROORGANISMS ISOLATED FROM SOIL SAMPLES CONTAMINATED WITH PESTICIDES

REPORTS ◽  
2021 ◽  
Vol 335 (1) ◽  
pp. 24-33
Author(s):  
G. Zh. Abdieva ◽  
P.S. Ualieva ◽  
A.M. Malik ◽  
U. A. Abylaeva ◽  
B. E. Rakhymzhanova
Keyword(s):  
Bacillus Amyloliquefaciens ◽  
High Growth ◽  
Biological Properties ◽  
Biochemical Properties ◽  
Soil Samples ◽  
Soil Bioremediation ◽  
Heterotrophic Microorganisms ◽  
Pseudomonas Plecoglossicida ◽  
Biotechnological Processes ◽  
Physiological And Biochemical

The article studied the biological properties, destructive activity of microorganisms extracted from soil samples of Kyzylkairat, Belbulak contaminated with pesticides and showed the features of their use in soil bioremediation. The morphological, cultural, physiological and biochemical properties of microorganisms extracted from soil samples contaminated with pesticides have been studied. Strains of K2, K3, KC1, CK2, AK1 and AK5 exhibited high activity based on biological properties. The isolated strains have been studied for destructive activity, among which four strains have been selected and recommended for identification: Pseudomonas plecoglossicida K2, Bacillus aryabhattai K3, Solibacillus isronensis KC1 and Bacillus amyloliquefaciens CK2. Among the selected strains, Solibacillus isronensis KC1 and Bacillus amyloliquefaciens CK2 exhibited high growth in an environment with different concentrations of pesticides. Further study of these strains will enable their use in biotechnological processes, in the decomposition of pesticides and in soil bioremediation.

scholarly journals Improper Light Curing of Bulkfill Composite Drives Surface Changes and Increases S. mutans Biofilm Growth as a Pathway for Higher Risk of Recurrent Caries around Restorations

2021 ◽  
Vol 9 (8) ◽  
pp. 83
Author(s):  
Haifa Maktabi ◽  
Maria Salem Ibrahim ◽  
Abdulrahman A. Balhaddad ◽  
Qoot Alkhubaizi ◽  
Isadora Martini Garcia ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Biofilm Formation ◽  
Clinical Performance ◽  
Biological Properties ◽  
Biofilm Growth ◽  
Curing Conditions ◽  
Dental Tissues ◽  
Radiant Exposure ◽  
Light Curing ◽  
Surface Changes

How dentists cure a resin-based material has deleterious effects on the material’s properties and its interaction with surrounding dental tissues. Biofilm accumulation has been implicated in the pathogenesis of carious lesions around dental restorations, with its composition manifesting expressed dysbiosis in patients suffering from dental caries. To evaluate the influence of varying radiant exposure on the degree of conversion (DC%), Streptococcus mutans biofilm growth, and surface roughness of bulk-fill composites under different light-curing conditions. Two light-curing units (LCU) at 600 and 1000 mW/cm2 were used to simulate curing conditions with different angulations (∢20° and ∢35°) or 2 mm-distance displacements of the LCU tip. The radiant exposure (RE) was assessed, and the composites were analyzed for DC%. Biofilm formation was induced over the bulk-fill composites and analyzed via colony-forming units counting and scanning electron microscopy (SEM). The surface roughness was analyzed via a profilometer and SEM after biofilm formation. Curing conditions with different angulation or displacement decreased RE compared to the “optimal condition”. The moderately (∢35°) angulated LCU tip and low (600 mW/cm2) radiant emittance significantly reduced the DC% (p < 0.05). The difference in DC% between the top and bottom of the composites ranged from 8 to 11% for 600 mW/cm2 and 10 to 20% for 1000 mW/cm2. Greater S. mutans biofilm and surface changes were found in composites with non-optimal RE delivery (e.g., tip displacement and angulation) (p < 0.05). Inadequate polymerization of bulk-fill composites was associated with more biofilm accumulation and surface topography changes. Overall, non-optimally performed curing procedures reduced the amount of delivered RE, which led to low DC%, more biofilm formation, and higher surface roughness. The improper light-curing of bulk-fill composites compromises their physicochemical and biological properties, which could lead to inferior clinical performance and reduced restorative treatments’ longevity.

scholarly journals Possibility of microbial remediation of soil contaminated by organic compounds

2020 ◽  
Vol 29 (1) ◽  
pp. 194-199
Author(s):  
Tsenguun Enkhtur ◽  
Tsolmongerel Erdenebayar ◽  
Bujidmaa Baasandorj ◽  
Tuul Nyambal ◽  
Khorloo Yundendorj
Keyword(s):  
Biological Properties ◽  
Biochemical Properties ◽  
Bacillus Circulans ◽  
Biochemical Characteristics ◽  
Long Period ◽  
Physiological And Biochemical Characteristics ◽  
Microbial Remediation ◽  
Brevibacillus Brevis ◽  
Physiological And Biochemical ◽  
Remediation Of Soil

Hexachlorocyclohexane (HCH) has been widely used in agriculture of our country to protect crops, vegetable fields, forest soils and plants from pests, and to treat scabies and other diseases in livestock. This pesticide is a highly toxic, carcinogenic, and banned substance that accumulates in human cells, tissues, and the environment over a long period of time. Incubated at 25°C for 3 days. The morphological, physiological, and biochemical characteristics of the two strains that differed in their biological properties and were dominant in the soil sample were determined. To determine the biochemical properties of these cultures, HCHDB1 (collection №1) culture was identified as 100% Bacillus circulans and HCHDB2 (collection № 2) culture was identified as 99% Brevibacillus brevis. Органик нэгдлээр бохирдсон хөрсийг микробиологийн аргаар цэвэршүүлэх боломж Гексахлорциклогексаныг манай улс хөдөө аж ахуйн салбарт өргөнөөр ашиглаж үр тариа, хүнсний ногооны талбай, ойн аж ахуйн хөрс, ургамлыг хортон шавжаас хамгаалах, мал амьтныг хамуу болон бусад төрлийн өвчнийг эмчлэхэд ашиглаж байсан. Энэхүү пестицид нь хүний эс, эд болон байгаль орчинд удаан хугацаагаар хуримтлагддаг, онцгой хортой, хорт хавдар үүсгэх нөлөөтэй, хэрэглэхийг хориглосон химийн бодис юм. Уг судалгаагаар гексахлорциклогексанаар бохирдсон хөрсний дээжинд илэрсэн бактерийн 12 омогийг 1%-ийн гексахлорциклогексан агуулсан хатуу (Nutrient agar) тэжээлт орчинд 25 хэмд 3 өдрийн турш өсгөвөрлөж ялган авсан. Биологийн шинж чанараараа ялгаатай бөгөөд уг хөрсний дээжинд доминант илэрсэн 2 омогийн морфологи, физиологи, биохимийн шинж чанарыг тодорхойлсон. Уг өсгөвөрүүдийн биохимийн шинж чанарыг тодорхойлоход HCHDB1 (коллекцийн №1) өсгөвөр 100%-иар Bacillus circulans, HCHDB2 (коллекцийн №2) өсгөвөр 99%-иар Brevibacillus brevis болохыг тус тус тодорхойлов.  Түлхүүр үг: гексахлорциклогексан, морфологи, физиологи, биохими, тэжээлт орчин

scholarly journals Adhesive properties of film-forming strains of staphylococci, isolated from different compartments of the human gastrointestinal tract

2017 ◽  
Vol 8 (4) ◽  
pp. 527-531 ◽  
Author(s):  
T. M. Shevchenko ◽  
O. Y. Hovorukha ◽  
Y. S. Voronkova ◽  
O. S. Voronkova
Keyword(s):  
Gastrointestinal Tract ◽  
Biofilm Formation ◽  
Food Poisoning ◽  
Biological Properties ◽  
Human Gastrointestinal Tract ◽  
Adhesive Properties ◽  
Initial Stage ◽  
Film Forming ◽  
Colonization Potential ◽  
High Level

Dysbiotic disorders, realized as changes in the composition of microbiota of different biotopes, are among the most difficult conditions to cure. This is due primarily to the fact that opportunistic microorganisms that actually mediate the development of such states are characterized by an increased colonization potential, which at the first stage of penetration into a biotope is realized as adhesion to the cell surface. When a microorganism successfully realises this stage it enters into a competitive relationship with the autochthonous flora and begins to inhibit its development. Such strategy becomes especially successful if the colonist has the ability to form a biofilm. It is known that the initial stage of biofilm formation is adhesion onto the surface, therefore, the study of adhesive properties of clinical strains opens the way for understanding the initial processes of development of dysbiosis and allows for the development of preventive measures. The aim of our research was to investigate the differences in the manifestation of adhesive properties of film-forming strains of staphylococci isolated from different compartments of the human gastrointestinal tract. We established that the frequency of detection of film-forming strains of staphylococci in different compartments of the gastrointestinal tract in the norm or during the development of lesions was for Staphylococcus aureus from 23.8% to 79.4%, and for S. epidermidis from 15.4% to 100%, which indicates the significant role of these microorganisms in the development of complications at the specified biotope. It was determined that the maximal manifestation of adhesive properties was typical for biofilm-forming strains of S. epidermidis and S. aureus isolated during intestinal dysbiosis. The average values of the adhesion index were 6.00 ± 1.41 and 5.88 ± 2.22 and the index of adhesion of microorganisms was 6.61 ± 1.46 and 6.64 ± 2.48 respectively. The lowest value of these indices for film-forming strains was determined for strains of staphylococci isolated from the gastrointestinal tracts of patients suffering from food poisoning – 2.60 ± 1.14 and 2.86 ± 1.23 respectively. The obtained data suggest that the ability for biofilm-formation and a high level of adhesion indexes indicate with a high probability that a strain will cause long-lasting lesions, such as dysbiosis. The determination of these markers at the diagnostic stage will allow a broader study of the biological properties of the strain, which may be the basis for the development of an individual, optimal therapeutic scheme that conforms with the tasks of personalized medicine. 

scholarly journals AttenuatedLegionella pneumophilaSurvives for a Long Period in an Environmental Water Site

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Nishida ◽  
Natsuko Nakagawa ◽  
Kenta Watanabe ◽  
Takashi Shimizu ◽  
Masahisa Watarai
Keyword(s):  
Legionella Pneumophila ◽  
Biofilm Formation ◽  
Environmental Water ◽  
Cell Number ◽  
Stress Factors ◽  
Clinical Strain ◽  
Serological Tests ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Long Period

Legionella pneumophilais known as a human pathogen and is ubiquitous in natural and artificial aquatic environments. Many studies have revealed the virulence traits ofL. pneumophilausing clinical strains and a number of studies for characterizing environmental strains are also reported. However, the association between the virulence and survivability in the environment is unclear. In the present study,L. pneumophilawas isolated from environmental water sites (Ashiyu foot spa, water fountain, and public bath), and the serogroups of isolated strains were determined by serological tests. Isolated strains were found to belong to serogroups SG1, SG2, SG3, SG4, SG5, SG8, SG9, and SG13. Untypeable strains were also obtained. Isolated strains were used for intracellular growth assay in a human monocytic cell line, THP-1. Among these strains, only an untypeable strain, named AY3, failed to replicate in THP-1. In addition, AY3 was maintained for a long period in an environmental water site, Ashiyu foot spa 2. Further, we compared the characteristics of several strains isolated from Ashiyu foot spa 2 and a clinical strain, Togus-1. AY3 failed to replicate in THP-1 cells but replicated in an amoeba model,Dictyostelium discoideum. Compared with Togus-1, the culturable cell number of environmental strains under stress conditions was higher. Moreover, biofilm formation was assessed, and AY3 showed the same degree of biofilm formation as Togus-1. Biofilm formation, replication in amoebae, and resistance against stress factors would explain the predominance of AY3 at one environmental site. Although the mechanism underlying the difference in the ability of AY3 to replicate in THP-1 cells or amoebae is still unclear, AY3 may abandon the ability to replicate in THP-1 cells to survive in one environment for a long period. Understanding the mechanisms ofL. pneumophilain replication within different hosts should help in the control of Legionnaires’ disease, but further study is necessary.

scholarly journals Myricetin as an Antivirulence Compound Interfering with a Morphological Transformation into Coccoid Forms and Potentiating Activity of Antibiotics against Helicobacter pylori

2021 ◽  
Vol 22 (5) ◽  
pp. 2695
Author(s):  
Paweł Krzyżek ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Magdalena Karwańska ◽  
Alina Wieliczko ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Morphological Transformation ◽  
High Tendency ◽  
Minimal Inhibitory Concentrations ◽  
Coccoid Form ◽  
Stomach Diseases ◽  
Fold Reduction ◽  
H Pylori

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.

scholarly journals An In Vitro Coumarin-Antibiotic Combination Treatment of Pseudomonas aeruginosa Biofilms

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Combination Treatment ◽  
Crude Extract ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Biofilm Growth ◽  
Antibiotic Combination

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.

scholarly journals Molecular Characterization of the Gene Encoding a New AmpC β-Lactamase in a Clinical Strain of Acinetobacter Genomic Species 3

2004 ◽  
Vol 48 (4) ◽  
pp. 1374-1378 ◽  
Author(s):  
Alejandro Beceiro ◽  
Lourdes Dominguez ◽  
Anna Ribera ◽  
Jordi Vila ◽  
Francisca Molina ◽  
...  
Keyword(s):  
Nucleotide Sequence ◽  
Molecular Characterization ◽  
Biochemical Properties ◽  
Clinical Strain ◽  
The Novel ◽  
Gene Encoding ◽  
Genomic Species ◽  
First Time

ABSTRACT A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this β-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC β-lactamase are reported

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