scholarly journals ANALYSIS OF MICROFLORA IN MODERN OUTPATIENT CLINIC

2020 ◽  
Vol 10 (1) ◽  
pp. 92-93
Author(s):  
Mikhail Pahomov ◽  
Artyom Morozov ◽  
Alexey Sergeev ◽  
Evgeny Mokhov, ◽  
Nikolay Sergeev ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Streptococcus Pyogenes ◽  
Resistance Genes ◽  
Bacterial Resistance ◽  
Antibiotic Sensitivity ◽  
Modern Medicine ◽  
Resistance To Antibiotics ◽  
The Right

Antibiotic resistance is a global problem of modern medicine. In the research a microflora of out-patient department visitors in 2018–2019 was examined. It was revealed that the most often microbes were Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli. The dynamics of bacterial resistance to antibiotics was also analyzed. The multiple bacterial resistance to antibiotics were detected. The data show a rapid resistance genes spread among non-hospital strains, which necessitates constant monitoring of antibiotic sensitivity in order to develop the right tactics to combat antibiotic resistance.

Molecular Characterization of Antibiotic Resistance Gene Pattern of Staphylococcus aureus and Escherichia coli in Mastitis Affected Dairy Cows

2020 ◽  
Author(s):  
T. Ramasamy ◽  
S. Keerthana ◽  
M.R. Srinivasan ◽  
D. Chandrasekar ◽  
K. Porteen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Molecular Characterization ◽  
Antibiotic Sensitivity ◽  
Growth Media ◽  
E Coli ◽  
Sensitivity Pattern

Background: Antimicrobial resistance is one of the latest challenges facing the scientific community. Raising the drug resistance is caused mainly by indiscriminate usage of antibiotics in human and animal subjects and the spread of antibiotic resistance between the two has an emerging global threat. Hence, current study aimed to study the antimicrobial resistance pattern and molecular detection of antibiotic resistance genes in Staphylococcus aureus and Escherichia coli isolated from mastitis affected cows. Methods: Milk samples from mastitis affected cows were subjected to antibiotic sensitivity test and screened for presence of Staphylococcus aureus and Escherichia coli using differential growth media. Molecular characterization of Staphylococcus aureus and Escherichia coli was done with the help of PCR by amplification of ‘nuc’ and ‘uspA’ gene respectively. MICs of Penicillin and Tetracycline were determined using microdilution method. Result: Antibiotic sensitivity pattern for Penicillin G, Ampicillin, Amoxycillin, Cefotaxime, Ceftriaxone, Azithromycin, Ciprofloxacin, Gentamicin, Oxytetracycline, Tetracycline and Vancomycin were 74.19%, 100%, 93.50%, 61.29%, 29%, 35.48%, 9.70%, 9.70%, 70.96% and 70.96% respectively. More than 87.90% of the S. aureus and 50% of the E. coli isolated were resistant to â-lactam antibiotics while 75% of the E.coli and 65.70% of the S. aureus isolated were resistant to Tetracycline antibiotics. The MICs of Penicillin for S.aureus and E.coli are 26.88 µg/ml and 13.54 µg/ml respectively and the MICs of Tetracycline for S. aureus and E. coli are 243.75 µg/ml and 960.93 µg/ml respectively which is 8-9 folds higher than the standard MICs. From the present study, it can be inferred that bovine mastitis cases are highly resistant to antimicrobial drugs. Results further indicate that Staphylococcus aureus and Escherichia coli are both resistant to Penicillin and Tetracycline with very high MIC.

Environmental pollutants induce noninherited antibiotic resistance to polymyxin B in Escherichia coli

2020 ◽  
Vol 15 (17) ◽  
pp. 1631-1643
Author(s):  
Dorin Harpaz ◽  
Robert S Marks ◽  
Ariel Kushmaro ◽  
Evgeni Eltzov
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Bacterial Resistance ◽  
Environmental Pollutants ◽  
Polymyxin B ◽  
Environmental Toxicants ◽  
Toxic Compounds ◽  
Resistance To Antibiotics ◽  
Low Concentrations ◽  
The Impact

Aim: The mechanisms behind antibiotic resistance by bacteria are important to create alternative molecules. Objective: This study focuses on the impact of environmental pollutants on bacterial resistance to antibiotics. Materials & methods: The effect of various environmental pollutants on noninherited bacterial resistance to antibiotics was examined. Results: The tolerance to the polymyxin-B antibiotic was shown to be conferred to Escherichia coli, by pretreatment with subinhibitory concentrations of environmental toxicants. The cell survival to a sublethal dosage of antibiotics was tested. Exposure to low concentrations of toxic compounds (500 ppb copper, 2% [v/v] ethanol or 0.5 μg/ml trimethoprim) stimulated the bacterial heat shock systems and led to increased tolerance to polymyxin B. Conclusion: Environmental pollutants induce a temporary bacterial noninheritable resistance to antibiotic.

scholarly journals Evolution of Resistance to Continuously Increasing Streptomycin Concentrations in Populations of Escherichia coli

2015 ◽  
Vol 60 (3) ◽  
pp. 1336-1342 ◽  
Author(s):  
Fabrizio Spagnolo ◽  
Conrad Rinaldi ◽  
Dannah Rae Sajorda ◽  
Daniel E. Dykhuizen
Keyword(s):  
Escherichia Coli ◽  
High Frequency ◽  
Bacterial Resistance ◽  
Low Frequency ◽  
Antibiotic Sensitivity ◽  
Modern Medicine ◽  
Bacterial Cells ◽  
Modern Biology ◽  
Content Type ◽  
Evolution Of Resistance

The evolution of antibiotic resistance in bacteria has become one of the defining problems in modern biology. Bacterial resistance to antimicrobial therapy threatens to eliminate one of the pillars of the practice of modern medicine. Yet, in spite of the importance of this problem, only recently have the dynamics of the shift from antibiotic sensitivity to resistance in a bacterial population been studied. In this study, a novel chemostat method was used to observe the evolution of resistance to streptomycin in a sensitive population ofEscherichia coli, which grew while the concentration of antibiotic was constantly increasing. The results indicate that resistant mutants remain at a low frequency for longer than expected and do not begin to rise to a high frequency until the antibiotic concentrations are above the measured MIC, creating a “lull period” in which there were few bacterial cells growing in the chemostats. Overall, mutants resistant to streptomycin were found in >60% of the experimental trial replicates. All of the mutants detected were found to have MICs far above the maximum levels of streptomycin to which they were exposed and reached a high frequency within 96 h.

scholarly journals Biocide-Induced Emergence of Antibiotic Resistance in Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Beatriz Merchel Piovesan Pereira ◽  
Xiaokang Wang ◽  
Ilias Tagkopoulos
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Bacterial Resistance ◽  
Cross Resistance ◽  
Multidrug Efflux ◽  
Adaptive Laboratory Evolution ◽  
Resistance To Antibiotics ◽  
Biocide Resistance ◽  
Resistant Strains ◽  
Underlying Mechanisms

Biocide use is essential and ubiquitous, exposing microbes to sub-inhibitory concentrations of antiseptics, disinfectants, and preservatives. This can lead to the emergence of biocide resistance, and more importantly, potential cross-resistance to antibiotics, although the degree, frequency, and mechanisms that give rise to this phenomenon are still unclear. Here, we systematically performed adaptive laboratory evolution of the gut bacteria Escherichia coli in the presence of sub-inhibitory, constant concentrations of ten widespread biocides. Our results show that 17 out of 40 evolved strains (43%) also decreased the susceptibility to medically relevant antibiotics. Through whole-genome sequencing, we identified mutations related to multidrug efflux proteins (mdfA and acrR), porins (envZ and ompR), and RNA polymerase (rpoA and rpoBC), as mechanisms behind the resulting (cross)resistance. We also report an association of several genes (yeaW, pyrE, yqhC, aes, pgpA, and yeeP-isrC) and specific mutations that induce cross-resistance, verified through mutation repairs. A greater capacity for biofilm formation with respect to the parent strain was also a common feature in 11 out of 17 (65%) cross-resistant strains. Evolution in the biocides chlorophene, benzalkonium chloride, glutaraldehyde, and chlorhexidine had the most impact in antibiotic susceptibility, while hydrogen peroxide and povidone-iodine the least. No cross-resistance to antibiotics was observed for isopropanol, ethanol, sodium hypochlorite, and peracetic acid. This work reinforces the link between exposure to biocides and the potential for cross-resistance to antibiotics, presents evidence on the underlying mechanisms of action, and provides a prioritized list of biocides that are of greater concern for public safety from the perspective of antibiotic resistance.Significance StatementBacterial resistance and decreased susceptibility to antimicrobials is of utmost concern. There is evidence that improper biocide (antiseptic and disinfectant) use and discard may select for bacteria cross-resistant to antibiotics. Understanding the cross-resistance emergence and the risks associated with each of those chemicals is relevant for proper applications and recommendations. Our work establishes that not all biocides are equal when it comes to their risk of inducing antibiotic resistance; it provides evidence on the mechanisms of cross-resistance and a risk assessment of the biocides concerning antibiotic resistance under residual sub-inhibitory concentrations.

The gut microbiota resistome provides development of drug resistance in causative agents of human infectious diseases

2017 ◽  
pp. 20-32 ◽  
Author(s):  
Е.Н. Ильина ◽  
Е.И. Олехнович ◽  
А.В. Павленко
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Integrated Approach ◽  
Modern Medicine ◽  
Pathogenic Microorganisms ◽  
Human Pathogens ◽  
Potential Source ◽  
Causative Agents ◽  
Bacterial Genes

С течением времени подходы к изучению резистентности к антибиотикам трансформировались от сосредоточения на выделенных в виде чистой культуры патогенных микроорганизмах к исследованию резистентности на уровне микробных сообществ, составляющих биотопы человека и окружающей среды. По мере того, как продвигается изучение устойчивости к антибиотикам, возникает необходимость использования комплексного подхода для улучшения информирования мирового сообщества о наблюдаемых тенденциях в этой области. Все более очевидным становится то, что, хотя не все гены резистентности могут географически и филогенетически распространяться, угроза, которую они представляют, действительно серьезная и требует комплексных междисциплинарных исследований. В настоящее время резистентность к антибиотикам среди патогенов человека стала основной угрозой в современной медицине, и существует значительный интерес к определению ниши, в которых бактерии могут получить гены антибиотикорезистентности, и механизмов их передачи. В данном обзоре мы рассматриваем проблемы, возникшие на фоне широкого использования человечеством антибактериальных препаратов, в свете формирования микрофлорой кишечника резервуара генов резистентности. Over the time, studies of antibiotic resistance have transformed from focusing on pathogenic microorganisms isolated as a pure culture to analysis of resistance at the level of microbial communities that constitute human and environmental biotopes. Advancing studies of antibiotic resistance require an integrated approach to enhance availability of information about observed tendencies in this field to the global community. It becomes increasingly obvious that, even though not all resistance genes can geographically and phylogenetically spread, the threat they pose is indeed serious and requires complex interdisciplinary research. Currently, the antibiotic resistance of human pathogens has become a challenge to modern medicine, which is now focusing on determining a potential source for bacterial genes of drug resistance and mechanisms for the gene transmission. In this review, we discussed problems generated by the widespread use of antibacterial drugs in the light of forming a reservoir of resistance genes by gut microflora.

scholarly journals Improved cytocompatibility and antibacterial properties of zinc-substituted brushite bone cement based on β-tricalcium phosphate

2021 ◽  
Vol 32 (9) ◽  
Author(s):  
Inna V. Fadeeva ◽  
Margarita A. Goldberg ◽  
Ilya I. Preobrazhensky ◽  
Georgy V. Mamin ◽  
Galina A. Davidova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tricalcium Phosphate ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Modern Medicine ◽  
Physiological Solution ◽  
Final Phase ◽  
Bone Replacement ◽  
Challenging Tasks ◽  
Murine Fibroblast

AbstractFor bone replacement materials, osteoconductive, osteoinductive, and osteogenic properties are desired. The bacterial resistance and the need for new antibacterial strategies stand among the most challenging tasks of the modern medicine. In this work, brushite cements based on powders of Zinc (Zn) (1.4 wt%) substituted tricalcium phosphate (β-TCP) and non-substituted β-TCP were prepared and investigated. Their initial and final phase composition, time of setting, morphology, pH evolution, and compressive strength are reported. After soaking for 60 days in physiological solution, the cements transformed into a mixture of brushite and hydroxyapatite. Antibacterial activity of the cements against Enterococcus faecium, Escherichia coli, and Pseudomonas aeruginosa bacteria strains was attested. The absence of cytotoxicity of cements was proved for murine fibroblast NCTC L929 cells. Moreover, the cell viability on the β-TCP cement containing Zn2+ ions was 10% higher compared to the β-TCP cement without zinc. The developed cements are perspective for applications in orthopedics and traumatology.

scholarly journals Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Xuehan Li ◽  
Tao Huang ◽  
Kai Xu ◽  
Chenglin Li ◽  
Yirong Li
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Virulence Genes ◽  
Mainland China ◽  
Geographical Location ◽  
Antibiotic Resistance Genes ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Staphylococcal Protein A

Abstract Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

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