doi: 10.3389/fmicb.2013.00096 A brief multi-disciplinary review on antimicrobial resistance in me... more doi: 10.3389/fmicb.2013.00096 A brief multi-disciplinary review on antimicrobial resistance in medicine and its linkage to the global environmental microbiota
ABSTRACTThis study examined differences in antibiotic-resistant soil bacteria and the presence an... more ABSTRACTThis study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low concentrations of certain antibiotic resistance genes were detected using multiplex quantitative real-time PCR (qPCR), withtet(B),aad(A), andstr(A) each present in only one soil andtet(M) andtet(W) detected in all soils. The most frequently detected resistance genes weretet(B),tet(D),tet(O),tet(T), andtet(W) for tetracycline resistance,str(A),str(B), andaacfor streptomycin resistance, anderm(C),erm(V),erm(X),msr(A),ole(B), andvgafor erythromycin resistance. Transposon genes specific for Tn916, Tn1549, TnB1230, Tn4451, and Tn5397were detected in soil bacterial isolates. The MIC ranges of...
Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species... more Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L. monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage.
Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes ... more Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes were examined. L. monocytogenes was found to be refractory to most treatments that promote rapid autolysis in other bacteria. Best rates of autolysis were obtained after resuspending the cells in Tris-hydrochloride buffer at 37 degrees C with the pH optimum at 8.0. Autolysis was also efficiently promoted by the surfactant Triton X-100. Antibiotics that interfere with the biosynthesis of the cell wall murein (peptidoglycan) caused death of the cells without autolysis after prolonged incubation in the presence of the drug. Only nisin, which has been shown to bind in vitro to the murein precursors lipid I and lipid II brings about autolysis of L. monocytogenes cells, although with slower kinetics than in the case of Tris-HCl and Triton.
Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences... more Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences between the primary and secondary forms of Xenorhabdus luminescens. Similarly, no significant differences were found in the overall protein composition of the cytoplasmic and outer membranes of both forms.
Basic, heat-stable proteins binding to double-stranded DNA (HASP) were isolated from the primary ... more Basic, heat-stable proteins binding to double-stranded DNA (HASP) were isolated from the primary and secondary forms of Xenorhabdus luminescens and their composition compared. Two of the proteins with low molecular weight are present in both the primary and secondary forms, whereas two others are present only in the latter. The described protein fractions may be involved in the regulation of transitions between the two forms of X. luminescens.
Listeria monocytogenes is a ubiquitous gram-positive, rod-shaped, widespread in nature, facultati... more Listeria monocytogenes is a ubiquitous gram-positive, rod-shaped, widespread in nature, facultative intracellular human and animal pathogen that causes infections collectively termed listeriosis. L. monocytogenes EGD encodes a total of 133 surface ...
Nitroaromatic compounds are present in the environment mainly as industry products. They pose a s... more Nitroaromatic compounds are present in the environment mainly as industry products. They pose a serious risk to our health (often exhibiting strong mutagenic and carcinogenic effect) as well as to the environment. Most of the nitroaromatic compounds are stable due to considerable resistance to degradation and they persist in the environment for a long time. In this review, we present the current state of knowledge concerning biodegradation of nitroaromatic compounds. In the first part, general information regarding their proprieties, synthesis and sources as well as pathways of microbial aerobic or anaerobic degradation are described. In some cases microorganisms have evolved several pathways of degradation specific nitrocompound, for instance nitrobenzene, which we describe in detail. The second part of the publication focuses on environmental bioremediation of nitrocompounds.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2011
Peptidoglycan (PG), the mighty miniwall, is the main structural component of practically all bact... more Peptidoglycan (PG), the mighty miniwall, is the main structural component of practically all bacterial cell envelopes and has been the subject of a wealth of research over the past 60 years, if only because its biosynthesis is the target of many antibiotics that have successfully been used in the treatment of bacterial infections. This review is mainly focused on the most recent achievements in research on the modification of PG glycan strands, which contribute to the resistance of bacteria to the host immune response to infection and to their own lytic enzymes, and on studies on the spatial organization of the macromolecule.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2004
In this preliminary report we show that a 29 kDa surface protein of Listeria monocytogenes EGD re... more In this preliminary report we show that a 29 kDa surface protein of Listeria monocytogenes EGD removed from cells with 4 M LiCl has peptidoglycan (murein) hydrolyzing activity, as revealed by zymographic analysis using Bacillus subtilis murein and heat-killed Micrococcus luteus cells casted in the gel. Following two-dimensional electrophoresis, the protein was electroblotted to PVDF membrane and its identity (FlaA) was revealed by sequencing. Peptidoglycan hydrolysing activity of FlaA purified by FPLC on Mono-S Sepharose against labelled Escherichia coli murein was demonstrated.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2004
Listeria monocytogenes is an opportunistic pathogen that causes infections collectively termed li... more Listeria monocytogenes is an opportunistic pathogen that causes infections collectively termed listeriosis, which are related to the ingestion of food contaminated with these gram-positive rods. The pathogenicity of L. monocytogenes is determined by the following virulence factors: listeriolysin O, protein ActA, two phospholipases C, internalins (In1A and In1B), protein CwhA and a metalloprotease. The bacterium is a model organism in studies on the pathogenesis of intracellular parasites. It is able to penetrate, multiply and propagate in various types of eukaryotic cells and is also able to overcome the three main barriers encountered in the host: the intestinal barrier, the blood-brain barrier and the placenta. Based on L. monocytogenes genome sequence analysis 133 surface proteins have been identified. In particular, the large number of proteins covalently bound to murein sets L. monocytogenes apart from other gram-positive bacteria. The ability of this pathogen to multiply in va...
Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes ... more Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes were examined. L. monocytogenes was found to be refractory to most treatments that promote rapid autolysis in other bacteria. Best rates of autolysis were obtained after resuspending the cells in Tris-hydrochloride buffer at 37 degrees C with the pH optimum at 8.0. Autolysis was also efficiently promoted by the surfactant Triton X-100. Antibiotics that interfere with the biosynthesis of the cell wall murein (peptidoglycan) caused death of the cells without autolysis after prolonged incubation in the presence of the drug. Only nisin, which has been shown to bind in vitro to the murein precursors lipid I and lipid II brings about autolysis of L. monocytogenes cells, although with slower kinetics than in the case of Tris-HCl and Triton.
Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences... more Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences between the primary and secondary forms of Xenorhabdus luminescens. Similarly, no significant differences were found in the overall protein composition of the cytoplasmic and outer membranes of both forms.
doi: 10.3389/fmicb.2013.00096 A brief multi-disciplinary review on antimicrobial resistance in me... more doi: 10.3389/fmicb.2013.00096 A brief multi-disciplinary review on antimicrobial resistance in medicine and its linkage to the global environmental microbiota
ABSTRACTThis study examined differences in antibiotic-resistant soil bacteria and the presence an... more ABSTRACTThis study examined differences in antibiotic-resistant soil bacteria and the presence and quantity of resistance genes in soils with a range of management histories. We analyzed four soils from agricultural systems that were amended with manure from animals treated with erythromycin and exposed to streptomycin and/or oxytetracycline, as well as non-manure-amended compost and forest soil. Low concentrations of certain antibiotic resistance genes were detected using multiplex quantitative real-time PCR (qPCR), withtet(B),aad(A), andstr(A) each present in only one soil andtet(M) andtet(W) detected in all soils. The most frequently detected resistance genes weretet(B),tet(D),tet(O),tet(T), andtet(W) for tetracycline resistance,str(A),str(B), andaacfor streptomycin resistance, anderm(C),erm(V),erm(X),msr(A),ole(B), andvgafor erythromycin resistance. Transposon genes specific for Tn916, Tn1549, TnB1230, Tn4451, and Tn5397were detected in soil bacterial isolates. The MIC ranges of...
Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species... more Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L. monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage.
Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes ... more Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes were examined. L. monocytogenes was found to be refractory to most treatments that promote rapid autolysis in other bacteria. Best rates of autolysis were obtained after resuspending the cells in Tris-hydrochloride buffer at 37 degrees C with the pH optimum at 8.0. Autolysis was also efficiently promoted by the surfactant Triton X-100. Antibiotics that interfere with the biosynthesis of the cell wall murein (peptidoglycan) caused death of the cells without autolysis after prolonged incubation in the presence of the drug. Only nisin, which has been shown to bind in vitro to the murein precursors lipid I and lipid II brings about autolysis of L. monocytogenes cells, although with slower kinetics than in the case of Tris-HCl and Triton.
Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences... more Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences between the primary and secondary forms of Xenorhabdus luminescens. Similarly, no significant differences were found in the overall protein composition of the cytoplasmic and outer membranes of both forms.
Basic, heat-stable proteins binding to double-stranded DNA (HASP) were isolated from the primary ... more Basic, heat-stable proteins binding to double-stranded DNA (HASP) were isolated from the primary and secondary forms of Xenorhabdus luminescens and their composition compared. Two of the proteins with low molecular weight are present in both the primary and secondary forms, whereas two others are present only in the latter. The described protein fractions may be involved in the regulation of transitions between the two forms of X. luminescens.
Listeria monocytogenes is a ubiquitous gram-positive, rod-shaped, widespread in nature, facultati... more Listeria monocytogenes is a ubiquitous gram-positive, rod-shaped, widespread in nature, facultative intracellular human and animal pathogen that causes infections collectively termed listeriosis. L. monocytogenes EGD encodes a total of 133 surface ...
Nitroaromatic compounds are present in the environment mainly as industry products. They pose a s... more Nitroaromatic compounds are present in the environment mainly as industry products. They pose a serious risk to our health (often exhibiting strong mutagenic and carcinogenic effect) as well as to the environment. Most of the nitroaromatic compounds are stable due to considerable resistance to degradation and they persist in the environment for a long time. In this review, we present the current state of knowledge concerning biodegradation of nitroaromatic compounds. In the first part, general information regarding their proprieties, synthesis and sources as well as pathways of microbial aerobic or anaerobic degradation are described. In some cases microorganisms have evolved several pathways of degradation specific nitrocompound, for instance nitrobenzene, which we describe in detail. The second part of the publication focuses on environmental bioremediation of nitrocompounds.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2011
Peptidoglycan (PG), the mighty miniwall, is the main structural component of practically all bact... more Peptidoglycan (PG), the mighty miniwall, is the main structural component of practically all bacterial cell envelopes and has been the subject of a wealth of research over the past 60 years, if only because its biosynthesis is the target of many antibiotics that have successfully been used in the treatment of bacterial infections. This review is mainly focused on the most recent achievements in research on the modification of PG glycan strands, which contribute to the resistance of bacteria to the host immune response to infection and to their own lytic enzymes, and on studies on the spatial organization of the macromolecule.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2004
In this preliminary report we show that a 29 kDa surface protein of Listeria monocytogenes EGD re... more In this preliminary report we show that a 29 kDa surface protein of Listeria monocytogenes EGD removed from cells with 4 M LiCl has peptidoglycan (murein) hydrolyzing activity, as revealed by zymographic analysis using Bacillus subtilis murein and heat-killed Micrococcus luteus cells casted in the gel. Following two-dimensional electrophoresis, the protein was electroblotted to PVDF membrane and its identity (FlaA) was revealed by sequencing. Peptidoglycan hydrolysing activity of FlaA purified by FPLC on Mono-S Sepharose against labelled Escherichia coli murein was demonstrated.
Polish journal of microbiology / Polskie Towarzystwo Mikrobiologów = The Polish Society of Microbiologists, 2004
Listeria monocytogenes is an opportunistic pathogen that causes infections collectively termed li... more Listeria monocytogenes is an opportunistic pathogen that causes infections collectively termed listeriosis, which are related to the ingestion of food contaminated with these gram-positive rods. The pathogenicity of L. monocytogenes is determined by the following virulence factors: listeriolysin O, protein ActA, two phospholipases C, internalins (In1A and In1B), protein CwhA and a metalloprotease. The bacterium is a model organism in studies on the pathogenesis of intracellular parasites. It is able to penetrate, multiply and propagate in various types of eukaryotic cells and is also able to overcome the three main barriers encountered in the host: the intestinal barrier, the blood-brain barrier and the placenta. Based on L. monocytogenes genome sequence analysis 133 surface proteins have been identified. In particular, the large number of proteins covalently bound to murein sets L. monocytogenes apart from other gram-positive bacteria. The ability of this pathogen to multiply in va...
Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes ... more Physiological conditions that could provide maximal rates of autolysis of Listeria monocytogenes were examined. L. monocytogenes was found to be refractory to most treatments that promote rapid autolysis in other bacteria. Best rates of autolysis were obtained after resuspending the cells in Tris-hydrochloride buffer at 37 degrees C with the pH optimum at 8.0. Autolysis was also efficiently promoted by the surfactant Triton X-100. Antibiotics that interfere with the biosynthesis of the cell wall murein (peptidoglycan) caused death of the cells without autolysis after prolonged incubation in the presence of the drug. Only nisin, which has been shown to bind in vitro to the murein precursors lipid I and lipid II brings about autolysis of L. monocytogenes cells, although with slower kinetics than in the case of Tris-HCl and Triton.
Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences... more Muropeptide analysis of muramidase-digested murein (peptidoglycan) did not reveal any differences between the primary and secondary forms of Xenorhabdus luminescens. Similarly, no significant differences were found in the overall protein composition of the cytoplasmic and outer membranes of both forms.
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