Selective pressure of biphenyl/polychlorinated biphenyls on the formation of aerobic bacterial associations and their biodegradative potential

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are linked to adverse health outcomes. PCB tissue levels are determinants of PCB toxicity; however, it is unclear how factors, such as an altered metabolism and/or a fatty liver, affect PCB distribution in vivo. We determined the congener-specific disposition of PCBs in mice with a liver specific deletion of cytochrome P450 reductase (KO), a model of fatty liver with impaired hepatic metabolism, and wildtype (WT) mice. Male and female KO and WT mice were exposed orally to Aroclor 1254, a technical PCB mixture. PCBs were quantified in adipose, blood, brain and liver tissues by gas chromatography-mass spectrometry. PCB profiles and levels in tissues were genotype and sex dependent. PCB levels were higher in the liver from KO compared to WT mice. PCB profiles showed clear differences between tissues from the same exposure group. While experimental tissue : blood partition coefficients in KO and WT mice did not follow the trends predicted using a composition-based model, the agreement between experimental and calculated partition coefficients was still reasonable. Thus, a fatty liver and/or an impaired hepatic metabolism alter the distribution of PCBs in mice and the magnitude of the partitioning of PCBs from blood into tissues can be approximated using composition-based models.<br>

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Determination of Polychlorinated Biphenyls (PCB) in Insulating Fluids

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2017-83-11-15-20 ◽

2017 ◽

Vol 83 (11) ◽

pp. 15-20

Author(s):

E. S. Brodskii ◽

◽

A. A. Shelepchikov ◽

G. A. Kalinkevich ◽

E. Ya. Mir-Kadyrova ◽

...

Keyword(s):

Polychlorinated Biphenyls

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Data on sediment quality and concentrations of polychlorinated biphenyls from the Lower Neponset River, Massachusetts, 2002-03

Open-File Report ◽

10.3133/ofr20041280 ◽

2004 ◽

Author(s):

Robert F. Breault ◽

Matthew G. Cooke ◽

Michael Merrill

Keyword(s):

Polychlorinated Biphenyls ◽

Sediment Quality

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Determination of polychlorinated biphenyls, selected persistent organochlorine pesticides, and polybrominated flame retardants in fillets of fishes from the 2007 Missouri Department of Conservation Monitoring Program

Open-File Report ◽

10.3133/ofr20091053 ◽

2009 ◽

Author(s):

Robert W. Gale ◽

Carl E. Orazio ◽

Michael J. McKee

Keyword(s):

Polychlorinated Biphenyls ◽

Organochlorine Pesticides ◽

Flame Retardants ◽

Monitoring Program ◽

Persistent Organochlorine

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Study of Alnus incana L. Moench fruit extract biologically active substances influence on resistance development in mls-resistant staphylococci skin isolates

Reports of Vinnytsia National Medical University ◽

10.31393/reports-vnmedical-2018-22(2)-05 ◽

2018 ◽

Vol 22 (2) ◽

pp. 263-266

Author(s):

R.V. Kutsyk ◽

O.I. Yurchyshyn

Keyword(s):

Selective Pressure ◽

Biological Response ◽

Biologically Active Substances ◽

Biologically Active ◽

Alnus Incana ◽

Fruit Extract ◽

Antimicrobial Drugs ◽

Resistance Development ◽

Subinhibitory Concentrations ◽

Active Substances

The emergence of microorganisms resistant strains is a natural biological response to the use of antimicrobial drugs that creates selective pressure, contributing to pathogens selection, survival and reproduction. The purpose of the investigation was to study the resistance development of staphylococci skin isolates to erythromycin and influence on it Alnus incana L. fruit extract subinhibitory concentrations. Development of resistance to erythromycin and influence on it Alnus incana L. fruit extract (extraction by 90% ethanol) subinhibitory concentrations were conducted with S epidermidis strains: sensitive and resistant to 14 and 15-membered macrolides. The study was carried out within 30 days by multiple consecutive passages of staphylococci test strains (concentration 1×107 CFU/ml) into test tubes containing broth and erythromycin ranging from 3 doubling dilutions above to doubling dilutions below the minimum inhibitory concentration. Statistical analysis of the results was carried out by one-and two-factor analysis of variance (ANOVA) and Microsoft Office Excel 2011. Rapid increase of resistance from 32 to 1024 μg/ml (F=34.2804; F> Fstand. max = 5.9874; p=0.0011) for S.epidermidis with a low level of resistance to 14 and 15-membered macrolides resistance to the erythromycine was observed. In the presence of Alnus incana L. fruit extract subinhibitory concentrations (¼ MIC), the initial MIC of erythromycin was decreased by 32 times to 1 μg/ml (F = 9.7497; F> Fstand. max = 5.9874; p = 0.0205). The sensitive strain after 30 passages did not develop resistance to erythromycin. Under the influence of erythromycin selective pressure, S.epidermidis strain with low initial level of MLS-resistance rapidly reaches a high-level resistance. Biologically active substances of the Alnus incana L. fruit extract significantly inhibit the resistance development in S. epidermidis to macrolides and eliminate it phenotypic features.

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