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1.
World J Microbiol Biotechnol ; 37(2): 22, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33428020

RESUMO

Quaternary ammonium salts (QASs) are ubiquitous in nature, being found in organisms ranging from microorganisms to vertebrates (e.g., glycine betaine, carnitine) where they have important cellular functions. QASs are also obtained by chemical synthesis. These compounds, due to their diverse chemical structure (e.g. monomeric QAS or gemini) and their biological properties, are widely used in medicine (as disinfectants, drugs, and DNA carriers), industry, environmental protection and agriculture (as preservatives, biocides, herbicides and fungicides). Discussed chemical compounds reduce the adhesion of microorganisms to various biotic and abiotic surfaces and cause the eradication of biofilms produced by pathogenic microorganisms. The properties of these chemicals depend on their chemical structure (length of the alkyl chain, linker and counterion), which has a direct impact on the physicochemical and biological activity of these compounds. QASs by incorporation into the membranes, inhibit the activity of proteins (H+-ATPase) and disrupt the transport of substances to the cell. Moreover, in the presence of QASs, changes in lipid composition (qualitative and quantitative) of plasma membrane are observed. The widespread use of disinfectants in commercial products can induce resistance in microorganisms to these surfactants and even to antibiotics. In this article we discuss the biological activity of QASs as cationic surfactants against microorganisms and their resistance to these compounds.


Assuntos
Resistência Microbiana a Medicamentos/efeitos dos fármacos , Compostos de Amônio Quaternário/metabolismo , Compostos de Amônio Quaternário/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Desinfetantes , Ácidos Graxos , Herbicidas/química , Interações Hidrofóbicas e Hidrofílicas , ATPases Translocadoras de Prótons/efeitos dos fármacos , Compostos de Amônio Quaternário/química , Sais , Tensoativos
2.
J Inorg Biochem ; 210: 111124, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32534287

RESUMO

Biological activity against reference and multi-drug resistant (MDR) clinical strains of fluoroquinolones (FQs): ciprofloxacin (HCp), norfloxacin (HNr), lomefloxacin (HLm) and sparfloxacin (HSf), phosphine ligands derived from those antibiotics and 14 phosphino copper(I) and copper(II) complexes with 2,9-dimethyl-1,10-phenanthroline, 1,10-phenanthroline or 2,2'-biquinoline have been determined. Almost all phosphines showed excellent antibacterial activity relative to reference strains (S. aureus ATCC 6538, E. coli ATCC 25922, K. pneumoniae ATCC 4352, and P. aeruginosa ATCC 27853). In rare cases P. aeruginosa rods showed natural insensitivity to oxides, and their copper(II) complexes. Most of the studied compounds showed weak antibacterial activity against clinical multi-drug resistant strains (MDR P. aeruginosa 16, 46, 325, 355, MRD A. baumanii 483 and MDR S. aureus 177). However, phosphines Ph2PCH2Sf (PSf), Ph2PCH2Lm (PLm) and their copper(I) complexes were characterized by the best antibacterial activity. In addition, PSf compounds, in which the activities relative to P. aeruginosa MDRs were relatively diverse, paid particular attention in our studies. Genetic and phenotypic studies of these strains showed significant differences between the strains, indicating different profiles of FQs resistance mechanisms. This may prove that a change in the spatial conformation of the PSf derivatives relative to the native form of HSf increased its affinity for the target site of action in gyrase, leading to selective inhibition of the multiplication of MDR strains. In conclusion, differences in PSf activity within closely related P. aeruginosa strains may indicate its diagnostic and therapeutic potential.


Assuntos
Antibacterianos/farmacologia , Complexos de Coordenação/farmacologia , Fluoroquinolonas/farmacologia , Fosfinas/farmacologia , Antibacterianos/química , Bactérias/efeitos dos fármacos , Complexos de Coordenação/química , Cobre/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fluoroquinolonas/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Fosfinas/química , Relação Estrutura-Atividade
3.
Gut Pathog ; 11: 10, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30828388

RESUMO

Extraintestinal pathogenic E. coli (ExPEC) are facultative pathogens that are part of the normal human intestinal flora. The ExPEC group includes uropathogenic E. coli (UPEC), neonatal meningitis E. coli (NMEC), sepsis-associated E. coli (SEPEC), and avian pathogenic E. coli (APEC). Virulence factors (VF) related to the pathogenicity of ExPEC are numerous and have a wide range of activities, from those related to bacteria colonization to those related to virulence, including adhesins, toxins, iron acquisition factors, lipopolysaccharides, polysaccharide capsules, and invasins, which are usually encoded on pathogenicity islands (PAIs), plasmids and other mobile genetic elements. Mechanisms underlying the dynamics of ExPEC transmission and the selection of virulent clones are still poorly understood and require further research. The time shift between colonization of ExPEC and the development of infection remains problematic in the context of establishing the relation between consumption of contaminated food and the appearance of first disease symptoms. What appears to be most difficult is to prove that ExPEC strains cause disease symptoms and to examine the mechanism of transition from the asymptomatic colonization of the intestines to the spreading of the bacteria outside the digestive system. A significant problem for researchers who are trying to ascribe ExPEC transmission to food, people or the environment is to draw the distinction between colonization of ExPEC and infection. Food safety is an important challenge for public health both at the production stage and in the course of its processing and distribution. Examination of the genetic similarity of ExPEC strains will allow to determine their origin from different sources. Many levels of genotyping have been proposed in which the typing of strains, plasmids and genes is compared in order to obtain a more complete picture of this complex problem. The aim of our study was to characterize E. coli strains isolated from humans, animals and food for the presence of bacterial genes encoding virulence factors such as toxins, and iron acquisition systems (siderophores) in the context of an increasing spread of ExPEC infections.

4.
Curr Med Chem ; 26(11): 1960-1978, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30378478

RESUMO

Salmonellosis continues to be a significant worldwide health problem. Despite rapid progress in identifying mechanisms of Salmonella virulence and resistance to chemicals, our knowledge of these mechanisms remains limited. Furthermore, it appears that the resistance to antibiotics can be amplified by ubiquitous usage of the disinfectants (biocides), both by industry and by ordinary households. Salmonella, as other Gram-negative bacteria possess outer membrane proteins (OMPs), which participate in maintaining cell integrity, adapting to environment, and interacting with infected host. Moreover, the OMPs may also contribute to resistance to antibacterials. This review summarizes the role of OMPs in Salmonella serum resistance, antibiotics resistance and cross-resistance to biocides. Although collected data do not allow to assign OMPs as markers of the Salmonella susceptibility to the above-mentioned factors, some of these proteins retain a dominant presence in certain types of resistance.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Farmacorresistência Bacteriana/fisiologia , Salmonella/metabolismo , Antibacterianos/efeitos adversos , Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Biomarcadores , Desinfetantes/efeitos adversos , Desinfetantes/farmacologia , Farmacorresistência Bacteriana/genética , Humanos , Salmonella/genética , Salmonella/imunologia
5.
Int J Mol Sci ; 18(7)2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28696348

RESUMO

A new emerging phenomenon is the association between the incorrect use of biocides in the process of disinfection in farms and the emergence of cross-resistance in Salmonella populations. Adaptation of the microorganisms to the sub-inhibitory concentrations of the disinfectants is not clear, but may result in an increase of sensitivity or resistance to antibiotics, depending on the biocide used and the challenged Salmonella serovar. Exposure of five Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg) strains to triamine-containing disinfectant did not result in variants with resistance to antibiotics, but has changed their susceptibility to normal human serum (NHS). Three biocide variants developed reduced sensitivity to NHS in comparison to the sensitive parental strains, while two isolates lost their resistance to serum. For S. Senftenberg, which exhibited the highest triamine tolerance (6 × MIC) and intrinsic sensitivity to 22.5% and 45% NHS, a downregulation of flagellin and enolase has been demonstrated, which might suggest a lower adhesion and virulence of the bacteria. This is the first report demonstrating the influence of biocide tolerance on NHS resistance. In conclusion, there was a potential in S. Senftenberg to adjust to the conditions, where the biocide containing triamine was present. However, the adaptation did not result in the increase of antibiotic resistance, but manifested in changes within outer membrane proteins' patterns. The strategy of bacterial membrane proteins' analysis provides an opportunity to adjust the ways of infection treatments, especially when it is connected to the life-threating bacteremia caused by Salmonella species.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Bactérias/metabolismo , Desinfetantes/farmacologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/metabolismo , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana
6.
Postepy Hig Med Dosw (Online) ; 69: 1042-55, 2015 Sep 20.
Artigo em Polonês | MEDLINE | ID: mdl-26400890

RESUMO

In recent years, the use of biocides has increased rapidly. One common example is triclosan, with wide application in households as well as medical and industrial fields, especially food industry and animal husbandry. Chemical disinfection is a major mean to control and eliminate pathogenic bacteria, particularly those with multidrug resistance (MDR) phenotype. However, exposition to biocides results in an adaptive response in microorganisms, causing them to display a wide range of resistance mechanisms. Numerous microorganisms are characterized by either natural resistance to chemical compounds or an ability to adapt to biocides using various strategies, such as: modification of cell surface structures (lipopolisaccharide), membrane fatty acids), over-expression of efflux pumps (a system for active transport of toxic compounds out of bacterial cell), enzymatic inactivation of biocides or altering biocide targets. For instance, it was shown that in vitro exposition of Salmonella Typhimurium to subinhibitory concentration of biocides (triclosan, quaternary ammonium compounds [QACs]) resulted in selection of variants resistant to tested biocides and, additionally, to acridine dyes and antibiotics. Bacillus subtilis and Micrococcus luteus strains isolated from chlorine dioxide containing disinfection devices were found to be resistant to chlorine dioxide and also to other oxidizing compounds, such as peracetic acid and hydrogen peroxide. Interaction between chemical compounds, including disinfectants and microbial cells, can create a serious threat to public health and sanitary-hygienic security. This phenomenon is connected with factor risk that intensify the probability of selection and dissemination of multidrug resistance among pathogenic bacteria.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Compostos Clorados/farmacologia , Desinfetantes/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Higiene , Óxidos/farmacologia , Saúde Pública/métodos , Humanos
7.
Gut Pathog ; 7: 18, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26185527

RESUMO

BACKGROUND: The O48 group comprises Salmonella bacteria containing sialic acid in the lipopolysaccharide (LPS). Bacteria with sialylated surface structures are described as pathogens that avoid immunological response of the host by making similar their surface antigens to the host's tissues (molecular mimicry). It is known that the smooth-type LPS of Salmonella enterica and outer membrane proteins (OMP) PgtE, PagC and Rck mediate serum resistant phenotype by affecting complement system (C). The aim of this study was to investigate C3 component activation by Salmonella O48 LPS and OMP. FINDINGS: In the present study, we examined C3 component deposition on the three Salmonella O48 strains: S. enterica subspecies enterica serovar Ngozi, S. enterica subsp. enterica sv. Isaszeg, and S. enterica subsp. arizonae containing sialic acid in the O-specific part of LPS. The greatest C3 deposition occurred on Salmonella sv. Isaszeg cells (p < 0.005) as well as on their LPS (low content of sialic acid in LPS) (p < 0.05) after 45 min of incubation in 50% human serum. Weaker C3 deposition ratio on the Salmonella sv. Ngozi (high content of sialic acid in LPS) and Salmonella subsp. arizonae (high content of sialic acid in LPS) cells correlated with the lower C3 activation on their LPS. Immunoblotting revealed that OMP isolated from the tested strains also bound C3 protein fragments. CONCLUSIONS: We suggest that activation of C3 serum protein is dependent on the sialic acid contents in the LPS as well as on the presence of OMP in the range of molecular masses of 35-48 kDa.

8.
Clin Biochem ; 45(16-17): 1374-82, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22749779

RESUMO

OBJECTIVES: Proteus mirabilis strains are human pathogens responsible for urinary tract infections, which may also be involved in rheumatoid arthritis (RA). DESIGN AND METHODS: We determined whether the binding site of anti-LPS antibodies on the O-polysaccharide part of P. mirabilis LPS correlates with the level of TLR4 (Thr399Ile) gene polymorphism in the sera of RA patients. We investigated the deposition of C3d and C5b complement components on the P. mirabilis LPS. The ELISA method used in this study was optimized with LAL test and laser interferometry. RESULTS: Depending on LPS P. mirabilis used in these studies, the amount of antibodies in RA patients sera varied. We did not observe a correlation between anti-LPS antibodies binding and the level of TLR4 (Thr399Ile) gene polymorphism. We found that the lower complement components deposition by O49 in contrast to O9 LPS correlates with its reduced sensitivities to human complement-mediated killing. CONCLUSION: The immunological response against P. mirabilis LPS might play a role in rheumatoid arthritis.


Assuntos
Anticorpos Antibacterianos/sangue , Artrite Reumatoide/imunologia , Lipopolissacarídeos/imunologia , Polimorfismo de Nucleotídeo Único , Proteus mirabilis/imunologia , Receptor 4 Toll-Like/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Anticorpos Antibacterianos/química , Artrite Reumatoide/sangue , Artrite Reumatoide/microbiologia , Estudos de Casos e Controles , Feminino , Frequência do Gene , Estudos de Associação Genética , Humanos , Interações Hidrofóbicas e Hidrofílicas , Interferometria , Luz , Lipopolissacarídeos/química , Masculino , Pessoa de Meia-Idade , Ligação Proteica , Receptor 4 Toll-Like/sangue
9.
Microb Ecol ; 59(3): 601-13, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19844648

RESUMO

Sialic acid (N-acetylneuraminic acid, NeuAc) plays an essential role in protecting gram-negative bacteria against the bactericidal activity of serum and may contribute to the pathogenicity of bacteria by mimicking epitopes that resemble host tissue components (molecular mimicry). The role of sialic acid (NeuAc)-containing lipopolysaccharides (LPS) of Salmonella O48 strains in the complement activation of normal human serum (NHS) was investigated. NeuAc-containing lipooligosaccharides cause a downregulation of complement activation and may serve to camouflage the bacterial surface from the immunological response of the host. Serotype O48 Salmonella strains have the O-antigen structure containing NeuAc while its serovars differ in outer membrane protein composition. In this study, the mechanisms of complement activation responsible for killing Salmonella O48 serum-sensitive rods by NHS were established. Four of such mechanisms involving pathways, which are important in the bactericidal mechanism of complement activation, were distinguished: only the classical/lectin pathways, independent activation of the classical/lectin or alternative pathway, parallel activation of the classical/lectin and alternative pathways, and only the alternative pathway important in the bactericidal action of human serum. To further study the role of NeuAc, its content in bacterial cells was determined by gas-liquid chromatography-mass spectrometry in relation to 3-deoxy-D-manno-2-octulosonic acid (Kdo), an inherent constituent of LPS. The results indicate that neither the presence of sialic acid in LPS nor the length of the O-specific part of LPS containing NeuAc plays a decisive role in determining bacterial resistance to the bactericidal activity of complement and that the presence of sialic acid in the structure of LPS is not sufficient to block the activation of the alternative pathway of complement. We observed that for three strains with a very high NeuAc/Kdo ratio the alternative pathways were decisive in the bactericidal action of human serum. The results indicated that those strains are not capable of inhibiting the alternative pathway very effectively. As the pathogenicity of most Salmonella serotypes remains undefined, research into the interactions between these bacterial cells and host organisms is indispensable.


Assuntos
Atividade Bactericida do Sangue , Ativação do Complemento , Lipopolissacarídeos/química , Ácido N-Acetilneuramínico/química , Salmonella/química , Complemento C3/análise , Complemento C4/análise , Via Alternativa do Complemento , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Salmonella/patogenicidade , Açúcares Ácidos/química
10.
Pol J Microbiol ; 58(3): 205-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19899612

RESUMO

Escherichia coli O56 were originally isolated from infected humans. Here it is reported that using the zwitterionic detergent (Zwittergent Z 3-14) to isolate outer membrane proteins (OMPs) from Escherichia coli O56 is suitable for their separation by two-dimensional electrophoresis (2-DE) using pH 3-10 immobilized pH gradient IPG strips (BIO-RAD).


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Detergentes/química , Eletroforese em Gel Bidimensional , Escherichia coli/metabolismo
11.
Postepy Hig Med Dosw (Online) ; 63: 471-84, 2009 Oct 19.
Artigo em Polonês | MEDLINE | ID: mdl-19850971

RESUMO

This paper presents some processes of the antibacterial effect of serum, which mainly results from the activities of complement (C) and lysozyme (muramidase, LZ). The C system consists ofa group of serum proteins and tissue fluids which are activated in a particular order. Complement,operating together with lysozyme, constitutes the main protection from microorganisms entering the body. Pathogenic microorganisms are able to avoid natural protective mechanisms by, among others, molecular mimicry, binding complement control proteins, or secreting proteolytic enzymes.The effectiveness of the cytolytic action of C proteins and LZ also depends on the surface structures of the microorganisms. Imbalance between the activation and deactivation of inflammatory reactions in the presence of pathogens can lead to various pathological states, such as autoimmunological diseases.


Assuntos
Infecções Bacterianas/imunologia , Atividade Bactericida do Sangue/imunologia , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Interações Hospedeiro-Patógeno/imunologia , Muramidase/imunologia , Soro/imunologia , Animais , Infecções Bacterianas/sangue , Humanos , Mimetismo Molecular
12.
Arch Immunol Ther Exp (Warsz) ; 57(5): 383-91, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19707721

RESUMO

INTRODUCTION: Proteus mirabilis bacilli play an important role in human urinary tract infections, bacteremia, and rheumatoid arthritis. The authors previously studied human complement C3 conversion by smooth-form P. mirabilis O10, O23, O30, and O43 lipopolysaccharides (LPSs) and showed that smooth Proteus LPSs fragmented C3 in a dose- and time-dependent manner. In the present study, one smooth P. mirabilis S1959 and its two polysaccharide-truncated LPSs isolated from an R mutant strain were used to study the C3 conversion. MATERIALS AND METHODS: The conversion of C3 to C3c by smooth and rough P. mirabilis LPSs was studied by capture ELISA and crossed immunoelectrophoresis. Proteins isolated from the outer membrane were analyzed by discontinuous sodium dodecyl sulfate gel electrophoresis. RESULTS: The smooth P. mirabilis S1959 (O3) strain was resistant to the bactericidal activity of human serum, in contrast to the Ra and Re mutant strains. The presence of an exposed core oligosaccharide in R110 LPS was not sufficient to protect the strain from serum-dependent killing. In addition to LPS structure, the outer-membrane proteins may also play roles in protecting the smooth P. mirabilis S1959 (O3) strain from the bactericidal action of serum. It was shown that the Ra P. mirabilis R110 and the Re P. mirabilis R45 mutants possess very different OMP compositions from that of the P. mirabilis S 1959 strain. CONCLUSION: Regardless of the complement resistance of the P. mirabilis strains, the S1959, R110, and R45 LPSs fragmented C3 and induced C3c neo-antigen exposure. The use of complement-deficient human serum allows the conclusion that the Re-type P. mirabilis R45 LPS fragmented C3 by the antibody-independent classical pathway.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Proteínas do Sistema Complemento/imunologia , Lipopolissacarídeos/farmacologia , Proteus mirabilis/química , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Ativação do Complemento/imunologia , Complemento C3/imunologia , Humanos , Lipopolissacarídeos/imunologia , Testes de Sensibilidade Microbiana , Infecções por Proteus/imunologia , Proteus mirabilis/imunologia , Soro/química , Soro/imunologia
13.
Pol J Microbiol ; 58(4): 363-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20380147

RESUMO

We report that using the zwitterionic detergent Zwittergent Z 3-14 to isolate outer membrane proteins (OMPs) from Salmonella 048 is suitable for their separation by two-dimensional electrophoresis (2-DE) in a capillary tube system. Sample preparation is a very crucial step for any bacterial proteomic study. Some modifications were introduced to the 2-DE protocol suggested by O'Farrell and BioRad, which significantly impaired the resolution of proteins. 2-DE analysis of OMPs may be helpful in the interpretation of the variable susceptibility of Salmonella 048 rods to the bactericidal activity of serum.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Detergentes/química , Eletroforese em Gel Bidimensional , Salmonella/citologia , Salmonella/metabolismo , Proteínas da Membrana Bacteriana Externa/química
14.
Pol J Microbiol ; 55(2): 153-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17419294

RESUMO

Urinary tract infections are frequently caused by Proteus mirabilis strains. In the previous studies there were defined the complete structures of O-polysaccharide parts of lipopolysaccharides from strains: P. mirabilis O3 (S1959), P. mirabilis O9 and P. mirabilis O18. In the present study it was investigated bactericidal effect of normal human serum (NHS) to P. mirabilis strains. We also focused on the diversity of outer membrane proteins (OMPs) being separated on a gel isolated from tested strains. Serial passage of P. mirabilis O18 in 90% normal bovine serum (NBS) contributed to over-expressing some classes of OMPs.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Atividade Bactericida do Sangue , Proteus mirabilis/metabolismo , Teste Bactericida do Soro , Proteínas da Membrana Bacteriana Externa/classificação , Humanos , Lipopolissacarídeos/metabolismo , Proteus mirabilis/imunologia , Infecções Urinárias/microbiologia
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