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1.
Yi Chuan ; 41(9): 863-874, 2019 Sep 20.
Artigo em Chinês | MEDLINE | ID: mdl-31549684

RESUMO

Membrane proteins play important functions not only as receptors and transporters, but also in many other important intracellular functions such as photosynthetic and respiratory electron transport. Identification of membrane proteins is a necessary step to understand their functions. Membrane proteins are generally highly hydrophobic and difficult to be resolved by aqueous solutions, and large-scale proteomic identification of membrane proteins has been a great technical challenge. Significant efforts have been invested in the field to improve the solubility of membrane proteins in aqueous solutions that are compatible for mass spectrometry analysis. This review summarizes the main technological achievements in the field of membrane proteomics particularly for the improvement of membrane protein identification, and uses the photosynthetic model cyanobacterium Synechocystis sp. PCC6803 as an example to illustrate how technology advances push forward the field in terms of the increased coverage of membrane proteome identification.


Assuntos
Proteoma , Proteômica/tendências , Synechocystis/genética , Proteínas de Bactérias/genética , Espectrometria de Massas
2.
Rev Soc Bras Med Trop ; 52: e20190237, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31508785

RESUMO

INTRODUCTION: The increased use of colistin against infections caused by Acinetobacter baumannii and Pseudomonas aeruginosa has resulted in colistin resistance. The purpose of this study was to detect plasmid-mediated mcr-1 gene in colistin-resistant A. baumannii and P. aeruginosa isolates. METHODS: A total of 146 clinical isolates of A. baumannii (n = 62) and P. aeruginosa (n = 84) were collected from the four largest tertiary care hospitals in Peshawar, Pakistan. All bacterial isolates were phenotypically screened for multidrug resistance using the Kirby-Baur disc diffusion method. The minimum inhibitory concentration (MIC) of colistin in all isolates was phenotypically performed using dilution methods. mcr-1 gene was detected through polymerase chain reaction and the nucleotide sequence of amplicon was determined using Sanger sequencing. RESULTS: Approximately 96.7% A. baumannii and 83.3% P. aeruginosa isolates were resistant to multiple antibiotics. Colistin resistance was found in 9.6% (6/62) of A. baumannii and 11.9% (10/84) of P. aeruginosa isolates. Among 16 colistin resistant isolates, the mcr-1 gene was detected in one A. baumannii (1.61% of total isolates; 16.6% of colistin resistant isolates) and one P. aeruginosa strain (1.19% of total isolates; 10% of colistin resistant isolates). Nucleotide BLAST showed 98-99% sequence similarity to sequences of the mcr-1 gene in GenBank. CONCLUSIONS: Our study reports, for the first time, the emergence of plasmid-mediated mcr-1-encoded colistin resistance in multidrug resistant strains of A. baumannii and P. aeruginosa. Further large scales studies are recommended to investigate the prevalence of this mode of resistance in these highly pathogenic bacteria.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Proteínas de Bactérias/genética , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Paquistão , Plasmídeos/genética , Pseudomonas aeruginosa/efeitos dos fármacos
3.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(7): 589-594, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31537242

RESUMO

Objective To construct and identify Bifidobacterium bifidum-vectored outer membrane protein F-I[rBb(pGEX-OprF-I)] vaccine of Pseudomonas aeruginosa and observe its protection against Pseudomonas aeruginosa infection in mice. Methods OprF and OprI genes were amplified by PCR, then the OprF-I fusion gene obtained by gene SOEing was digested and ligated into the vector pGEX-1λT to construct the recombinant plasmid pGEX-OprF-I. The plasmid was transformed into Bifidobacterium bifidum (Bb) by electroporation, and the rBb(pGEX-OprF-I) vaccine was constructed and identified by double enzyme digestion and PCR. Expression products of the vaccine induced by IPTG were analyzed and identified by SDS-PAGE and Western blot analysis. Twenty-one BALB/c mice were randomly divided into rBb(pGEX-OprF-I) vaccine group, Bb-pGEX-1λT empty vector group and Bb control group. The 5×108 CFUs vaccine was intragastrically administered for 3 consecutive days per week for 3 weeks. All mice were challenged intranasally with 5×107 CFUs of PA01 strain at the 4th week after the first immunization. At the 2nd week after the challenge, all mice were sacrificed to count the lung bacteria loads. IgG levels in sera from the mice before immunization, 4th week after the first immunization and 2nd week after the challenge were detected by routine ELISA. Results A total of 1289 bp OprF-I fusion gene was amplified by PCR. Double enzyme digestion and PCR identification confirmed that the gene was ligated into pGEX-1λT and transformed into Bb, and the rBb(pGEX-OprF-I) vaccine was successfully constructed. SDS-PAGE showed that the fusion protein with a relative molecular mass (Mr) of about 68 000 could be expressed by IPTG-induced vaccine. Western blot analysis indicated that the protein could be specifically recognized by the sera of Pseudomonas aeruginosa-infected mice. The number of bacteria colonies in the lung of the mice immunized with rBb(pGEX-OprF-I) vaccine was significantly lower than that of the control group. The IgG levels in the sera of the immunized mice increased successively at 4th week after the first immunization and 2nd week after the challenge, and higher than that in the other control groups at the same time point. Conclusion The rBb(pGEX-OprF-I) vaccine has been successfully constructed, and it may take a certain protective effect on the mice against Pseudomonas aeruginosa infection.


Assuntos
Proteínas de Bactérias/imunologia , Bifidobacterium bifidum , Lipoproteínas/imunologia , Infecções por Pseudomonas/prevenção & controle , Vacinas contra Pseudomonas/imunologia , Animais , Camundongos , Camundongos Endogâmicos BALB C , Pseudomonas aeruginosa , Distribuição Aleatória , Proteínas Recombinantes de Fusão/imunologia
4.
Sheng Wu Gong Cheng Xue Bao ; 35(9): 1662-1675, 2019 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-31559748

RESUMO

The fcl gene encodes GDP-fucose synthase, which catalyzes two-step differential isomerase and reductase reactions in the synthesis of GDP-L-fucose from GDP-D-mannose. It also participates in the biosynthesis of amino sugar and ribose sugar, and is one of the key enzymes to regulate the metabolism of sugar and nucleotides in organisms. The presence of fcl gene in Saccharopolyspora pogona was found through sequencing result of genome. The mutant S. pogona-fcl and S. pogona-Δfcl were constructed by gene engineering technology. The results showed that the gene had an effects on growth and development, protein expression and transcriptional level, insecticidal activity, and biosynthesis of butenyl-spinosyn of Saccharopolyspora pogona. The results of HPLC analysis showed that the yield of butenyl-spinosyn in S. pogona-Δfcl was 130% compared with that in S. pogona, which reduced by 25% in S. pogona-fcl. The results of determination of insecticidal activity showed that S. pogona-Δfcl had a stronger insecticidal activity against Helicoverpa armigera than that of S. pogona, while the S. pogona-fcl had a lower insecticidal activity against Helicoverpa armigera compared with S. pogona. Scanning electron microscopy (SEM) was used to observe the morphology of the mycelia. It was found that the surface of the S. pogona-Δfcl was wrinkled, and the mycelium showed a short rod shape. There was no significant difference in mycelial morphology between S. pogona-fcl and S. pogona. Aboved all showed that deletion of fcl gene in S. pogona hindered the growth and development of mycelia, but was beneficial to increase the biosynthesis of butenyl-spinosyn and improve insecticidal activity. Whereas the fcl gene over-expression was not conducive to the biosynthesis of butenyl-spinosyn and reduced their insecticidal activity. SDS-PAGE results showed that the difference of protein expression among the three strains was most obvious at 96 hours, which was identified by real-time fluorescence quantitative polymerase chain reaction, the results showed that there were significant differences of related genes in transcriptional levels among the three strains. Based on the results of the study, a network metabolic control map was constructed to analyze the effect of fcl gene on growth and the regulation pathway of butenyl-spinosyn biosynthesis, which provided an experimental basis for revealing the regulation mechanism of butenyl-spinosyn biosynthesis and related follow-up studies.


Assuntos
Saccharopolyspora , Proteínas de Bactérias , Engenharia Genética , Inseticidas , Macrolídeos
5.
Ann Agric Environ Med ; 26(3): 405-408, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31559794

RESUMO

INTRODUCTION: Carbapenemase-producing Enterobacteriaceae have spread rapidly through the countries and continents to become a global concern. One of the main reservoirs of NDM-1 positive strains from the Enterobacteriaceae family is the Indian subcontinent (Bangladesh, Pakistan, India). MATERIAL AND METHODS: During June 2017 - June 2018, rectal swab samples were collected routinely in all patients returning to Poland from South and South-East Asia. During molecular examinations gene blaNDM-1 encoding NDM-1 carbapenemase was detected. RESULTS: 31 patients were examined after returning to Poland from a trip to South and South-East Asia. The presence of New Delhi Metallo-ß-lactamase-1 producing Escherichia coli and Klebsiella pneumoniae was confirmed in three patients (9.7%) returning to Poland from travels to India. All the positive patients were hospitalized during the trip in a New Delhi hospital. CONCLUSIONS: Digestive tract carriage of NDM in a group of Polish travelers is a significant health and epidemiological problem. The study confirms the necessity for screening for carbapenemase-producing Enterobacteriaceae (CPE), particularly among travellers. Rectal swabs should be collected in every case of patients returning from international trips, and the possibility of environment-associated infections should be emphasized.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/enzimologia , Klebsiella pneumoniae/enzimologia , Viagem , beta-Lactamases/metabolismo , Adulto , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Feminino , Humanos , Índia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Polônia , beta-Lactamases/genética
6.
Gene ; 720: 144082, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31476406

RESUMO

The enzyme ß-Ketoacyl ACP synthase I (KasA) is a potent drug target in mycolic acid pathway of Mycobacterium tuberculosis (Mtb). In the present study, we investigated the structural dynamics of wild-type (WT) and mutants KasA (D66N, G269S, G312S, and F413L) in both monomer and dimer form to provide insight into protein structural stability. To gain better understanding of structural flexibility of KasA, combined molecular dynamics and essential dynamics were employed to analyze the conformational changes induced by non-active site mutations. The results confirm that non-active site mutations lower the structural stability in dimer KasA as compared to WT. The protein network topology and close residue interactions of WT and mutant residues of KasA have been predicted through residue interaction network analysis (RIN). Non-active site mutations distort RIN architecture and subsequently affect the drug binding landscape. T-pad associated with mode vector analysis comprehensively pronounces the structural impact caused by non-active site mutations. It also identified the critical fluctuating residues present in the gate segment (GS) region (115-147). The non-active site mutations altered the structural stability of the mutant protein structures, and these mutations may be a cause for the resistance mechanism of KasA against anti-tuberculosis drugs. Further, it is observed that dimer mutant KasA proteins display much more structural flexibility than WT at the ligand binding site which is evident from the binding site analysis and hydrogen bond interaction patterns. This study provides a better understanding of the structural dynamic behaviour of KasA mutants, thereby facilitating the need to find a novel and potent inhibitor against Mtb.


Assuntos
3-Oxoacil-(Proteína de Transporte de Acila) Sintase/química , Proteínas de Bactérias/química , Isoenzimas/química , Proteínas Mutantes/química , Mutação , Mycobacterium tuberculosis/enzimologia , Tuberculose/microbiologia , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/genética , Proteínas de Bactérias/genética , Isoenzimas/genética , Simulação de Dinâmica Molecular , Proteínas Mutantes/genética , Conformação Proteica , Tuberculose/genética , Tuberculose/metabolismo
7.
Gene ; 720: 144094, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31476407

RESUMO

Fourteen different insertion sequences belonging to seven families were identified in the genome of Streptococcus agalactiae. Among them, IS1548, a mobile element of the ISAs1 family, was linked to clonal complex (CC) 19 strains associated with neonatal meningitis and endocarditis. IS1548 impacts S. agalactiae in two reported ways: i) inactivation of virulence genes by insertion in an open reading frame (e.g. hylB or cpsD), ii) positive modulation of the expression of a downstream gene by insertion in an intergenic region (e.g. lmb). We previously identified an unknown integration site of IS1548 in the intergenic region between the folK and the murB genes involved in folate and peptidoglycan biosynthesis, respectively. In this work, we analyzed the prevalence of IS1548 in a large collection of nine hundred and eleven S. agalactiae strains. IS1548 positive strains belong to twenty-nine different sequence types and to ten CCs. The majority of them were, however, clustered within sequence type 19 and sequence type 22, belonging to CC19 and CC22, respectively. In contrast, IS1548 targets the folK-murB intergenic region exclusively in CC19 strains. We evaluated the impact of the insertion of IS1548 on the expression of murB by locating transcriptional promoters influencing its expression in the presence or absence of IS1548 and by comparative ß-galactosidase transcriptional fusion assays. We found that in the absence of IS1548, genes involved in folate biosynthesis are co-transcribed with murB. As it was postulated that a folic acid mediated reaction may be involved in cell wall synthesis, this co-transcription could be necessary to synchronize these two processes. The insertion of IS1548 in the folK-murB intergenic region disrupt this co-transcription. Interestingly, we located a promoter at the right end of IS1548 that is able to initiate additional transcripts of murB. The insertion of IS1548 in this region has thus a dual and divergent impact on the expression of murB. By comparative ß-galactosidase transcriptional fusion assays, we showed that, consequently, the overall impact of the insertion of IS1548 results in a minor decrease of murB gene transcription. This study provides new insights into gene expression effects mediated by IS1548 in S. agalactiae.


Assuntos
Proteínas de Bactérias/genética , DNA Intergênico , Regulação Bacteriana da Expressão Gênica , Sequências Repetitivas Dispersas , Mutagênese Insercional , Peptidoglicano/biossíntese , Streptococcus agalactiae/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , DNA Bacteriano/genética , Regiões Promotoras Genéticas , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/crescimento & desenvolvimento , Streptococcus agalactiae/metabolismo
8.
Pestic Biochem Physiol ; 159: 1-8, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400771

RESUMO

We examined the molecular regulation of porphyrin biosynthesis and protective responses in transgenic rice (Oryza sativa) expressing Bradyrhizobium japonicum Fe-chelatase (BjFeCh) after treatment with acifluorfen (AF). During the photodynamic stress imposed by AF, transcript levels of BjFeCh in transgenic plants increased greatly; moreover, transcript levels of OsFeCh2 remained almost constant, whereas in wild type (WT) plants they were considerably down-regulated. In the heme branch, transgenic plants exhibited greater levels of OsFC and HO transcripts than WT plants in the untreated stems as well as in the AF-treated leaves and stems. Both WT and transgenic plants treated with AF substantially decreased transcript levels for all the genes in the chlorophyll branch, with less decline in transgenic plants. After AF treatment, ascorbate (Asc) content and the redox Asc state greatly decreased in leaves of WT plants; however, in transgenic plants both parameters remained constant in leaves and the Asc redox state increased by 20% in stems. In response to AF, the leaves of WT plants greatly up-regulated CatA, CatB, and GST compared to those of transgenic plants, whereas, in the stems, transgenic plants showed higher levels of CatA, CatC, APXb, BCH, and VDE. Photochemical quenching, qP, was considerably dropped by 31% and 18% in WT and transgenic plants, respectively in response to AF, whereas non-radiative energy dissipation through non-photochemical quenching increased by 77% and 38% in WT and transgenic plants, respectively. Transgenic plants treated with AF exhibited higher transcript levels of nucleus-encoded photosynthetic genes, Lhcb1 and Lhcb6, as well as levels of Lhcb6 protein compared to those of WT plants. Our study demonstrates that expression of BjFeCh in transgenic plants influences not only the regulation of porphyrin biosynthesis through maintaining higher levels of gene expression in the heme branch, but also the Asc redox function during photodynamic stress caused by AF.


Assuntos
Proteínas de Bactérias/metabolismo , Bradyrhizobium/enzimologia , Ferroquelatase/metabolismo , Nitrobenzoatos/farmacologia , Oryza/metabolismo , Porfirinas/biossíntese , Proteínas de Bactérias/genética , Ferroquelatase/genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Plantas Geneticamente Modificadas
9.
Phys Chem Chem Phys ; 21(32): 17950-17958, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31384849

RESUMO

The A. aeolicus intrinsically disordered protein FlgM has four well-defined α-helices when bound to σ28, but in water FlgM undergoes a change in tertiary structure. In this work, we investigate the structure of FlgM in aqueous solutions of the ionic liquid [C4mpy][Tf2N]. We find that FlgM is induced to fold by the addition of the ionic liquid, achieving average α-helicity values similar to the bound state. Analysis of secondary structure reveals significant similarity with the bound state, but the tertiary structure is found to be more compact. Interestingly, the ionic liquid is not homogeneously dispersed in the water, but instead aggregates near the protein. Separate simulations of aqueous ionic liquid do not show ion clustering, which suggests that FlgM stabilizes ionic liquid aggregation.


Assuntos
Proteínas de Bactérias/química , Imidas/química , Proteínas Intrinsicamente Desordenadas/química , Líquidos Iônicos/química , Modelos Moleculares , Pirrolidinas/química , Bases de Dados de Proteínas , Conformação Proteica em alfa-Hélice , Dobramento de Proteína , Termodinâmica , Água
10.
Pestic Biochem Physiol ; 158: 54-60, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378361

RESUMO

Extensive planting of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has spurred increasingly rapid evolution of resistance in pests. In the pink bollworm, Pectinophora gossypiella, a devastating global pest, resistance to Bt toxin Cry1Ac produced by transgenic cotton is linked with mutations in a gene (PgCad1) encoding a cadherin protein that binds Cry1Ac in the larval midgut. We previously reported a long non-coding RNA (lncRNA) in intron 20 of cadherin alleles associated with both resistance and susceptibility to Cry1Ac. Here we tested the hypothesis that reducing expression of this lncRNA decreases transcription of PgCad1 and susceptibility to Cry1Ac. Quantitative RT-PCR showed that feeding susceptible neonates small interfering RNAs (siRNAs) targeting this lncRNA but not PgCad1 decreased the abundance of transcripts of both the lncRNA and PgCad1. Moreover, neonates fed the siRNAs had lower susceptibility to Cry1Ac. The results imply that the lncRNA increases transcription of PgCad1 and susceptibility of pink bollworm to Cry1Ac. The results suggest that disruption of lncRNA expression could be a novel mechanism of pest resistance to Bt toxins.


Assuntos
Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/farmacologia , Caderinas/genética , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Mariposas/efeitos dos fármacos , RNA Longo não Codificante/genética , Transcrição Genética/genética , Animais , Bacillus thuringiensis/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mariposas/genética , Mariposas/metabolismo , Controle Biológico de Vetores
11.
MMWR Morb Mortal Wkly Rep ; 68(30): 664-666, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31369523

RESUMO

Candida auris is an emerging drug-resistant yeast that causes outbreaks in health care facilities; cases have been reported from approximately 30 countries. U.S. cases of C. auris are likely the result of importation from abroad followed by extensive local transmission in health care settings (1). Early detection of Candida auris is key to preventing its spread. C. auris frequently co-occurs with carbapenemase-producing organisms (CPOs), like carbapenem-resistant Enterobacteriaceae (CRE), organisms for which testing and public health response capacity substantially increased beginning in 2017. In September 2018, the Maryland Department of Health (MDH) was notified of a hospitalized resident with CPO infection and colonization and recent hospitalization in Kenya. In light of this history, the patient was screened for C. auris and found to be colonized. Public health responses to CPOs can aid in the early identification of C. auris. As part of CPO investigations, health departments should assess whether the patient has risk factors for C. auris and ensure that patients at risk are tested promptly.


Assuntos
Proteínas de Bactérias/biossíntese , Candida/isolamento & purificação , Candidíase/diagnóstico , Hospitalização/estatística & dados numéricos , beta-Lactamases/biossíntese , Humanos , Quênia , Estados Unidos
12.
Epidemiol Mikrobiol Imunol ; 68(2): 99-102, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31398983

RESUMO

The increasing incidence of multiresistant bacterial strains is currently a serious health concern. These pathogens are often the cause of nosocomial infections with limited treatment options and high fatality rates. A case report is presented of an uncommon detection of four different species (Citrobacter freundii, Klebsiella pneumoniae, Escherichia coli, and Morganella morganii) producing the same type of carbapenemase, KPC-2, in a female patient during her complicated long-term hospital stay. Resistance was probably spread to other species by horizontal transmission of plasmids carrying the blaKPC-2 genes. The implementation of strict anti-epidemic measures prevented further spread of these carbapenem-resistant bacteria.


Assuntos
Antibacterianos , Bactérias , Infecções Bacterianas , Infecção Hospitalar , beta-Lactamases , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Infecções Bacterianas/microbiologia , Proteínas de Bactérias/genética , Coinfecção/microbiologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana/genética , Feminino , Transferência Genética Horizontal , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , beta-Lactamases/genética
13.
World J Microbiol Biotechnol ; 35(8): 127, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375931

RESUMO

Aeromonas hydrophila is a Gram-negative bacterium that causes serious infections in aquaculture and exhibits significant multidrug resistance. The LysR-type transcriptional regulator (LTTR) family proteins are a well-known group of transcriptional regulators involved in diverse physiological functions. However, the role of LTTRs in the regulation of bacterial resistance to antibiotics is still largely unknown. In this study, to further investigate the role of four putative LTTR family proteins (A0KIU1, A0KJ82, A0KPK0, and A0KQ63) in antibiotic resistance in A. hydrophila, their genes were cloned and overexpressed in engineered Escherichia coli. After the optimization of experimental conditions including incubation time, temperature, and IPTG concentration, these proteins were successfully purified, and their specific antibodies against mice were obtained. Using western blot analysis, we found that these LTTR family proteins were downregulated in A. hydrophila following antibiotic treatment, indicating that they may be involved in the regulation of antibiotic resistance. Additionally, minimum inhibitory concentration (MIC) assays of chloramphenicol (CM), chlortetracycline (CTC), ciprofloxacin (CF), furazolidone (FZ), and balofloxacin (BF) in E. coli showed that overexpression of these LTTRs led to increased sensitivity to several antibiotics. To further validate their functional role in antibiotic resistance, we demonstrated that bacteria with loss of A0KQ63 (ΔAHA_3980) exhibited multi-drug resistance properties. Our results indicate that these LTTR family proteins may play an important role in the antibiotic resistance of A. hydrophila, and the that underlying mechanisms controlling antibiotic resistance should be further investigated.


Assuntos
Aeromonas hydrophila/efeitos dos fármacos , Aeromonas hydrophila/genética , Farmacorresistência Bacteriana , Regulação Bacteriana da Expressão Gênica , Genes Reguladores , Fatores de Transcrição/metabolismo , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Western Blotting , Clonagem Molecular , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Deleção de Genes , Expressão Gênica , Perfilação da Expressão Gênica , Genes Bacterianos , Camundongos , Testes de Sensibilidade Microbiana , Fatores de Transcrição/análise , Fatores de Transcrição/genética
14.
World J Microbiol Biotechnol ; 35(9): 140, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31451938

RESUMO

Pseudomonas species are the most versatile of all known bacteria for metabolic flexibility and the extent of host range from plants to humans that remains unmatched. The evolution of diverse metabolic strategies in these species to adapt to the fluctuating environment guarantees high fitness as well as the ability to withstand stress at multiple levels. These abilities in Pseudomonas species are imprinted by an adaptable genetic repertoire through the integration of external and internal signals via complex regulatory networks. One of the main regulatory networks that lead to optimal growth, survival and cellular robustness is the phenomenon of carbon catabolite repression (CCR). Even though a large array of information is available, the molecular machinery and the mechanism of CCR in Pseudomonas are distinctly diverse from Escherichia coli and Bacillus subtilis. In Pseudomonas, the Crc and Hfq proteins, CbrAB two-component systems and the CrcZ/CrcY small RNA are key components of CCR. The main focus of this review is to elucidate the mechanism of CCR and the accessories involved in regulation of preferred carbon source utilisation over non-preferred ones and how CCR influences the virulence, antibiotic resistance, bioremediation and plant growth promotion pathways. Furthermore, we have also tried to shed some light on the "omics" approaches which can provide deep mechanistic insights into the regulation of CCR. Understanding the mechanistic picture of key regulatory entities and mechanism responsible for metabolic flexibility will create opportunities for exploitation of these versatile prokaryotes in several biotechnological processes.


Assuntos
Proteínas de Bactérias/metabolismo , Repressão Catabólica , Regulação Bacteriana da Expressão Gênica , Fator Proteico 1 do Hospedeiro/metabolismo , Pseudomonas/metabolismo , RNA Bacteriano/genética , Proteínas de Bactérias/genética , Carbono/metabolismo , Fator Proteico 1 do Hospedeiro/genética , Pseudomonas/genética , RNA Bacteriano/metabolismo
15.
Microbiol Res ; 227: 126309, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421713

RESUMO

The phosphorus availability in soil ranged from <0.01 to 1 ppm and found limiting for the utilization by plants. Hence, phosphate solubilizing bacteria (PSB) proficiently fulfill the phosphorus requirement of plants in an eco-friendly manner. The PSB encounter dynamic and challenging environmental conditions viz., high temperature, osmotic, acid, and climatic changes often hamper their activity and proficiency. The modern trend is shifting from isolation of the PSB to their genetic potentials and genome annotation not only for their better performance in the field trials but also to study their ability to cope up with stresses. In order to withstand environmental stress, bacteria need to restructure its metabolic network to ensure its survival. Pi starving condition response regulator (PhoB) and the mediator of stringent stress response alarmone (p)ppGpp known to regulate the global regulatory network of bacteria to provide balanced physiology under various stress condition. The current review discusses the global regulation and crosstalk of genes involved in phosphorus homeostasis, solubilization, and various stress response to fine tune the bacterial physiology. The knowledge of these network crosstalk help bacteria to respond efficiently to the challenging environmental parameters, and their physiological plasticity lead us to develop proficient long-lasting consortia for plant growth promotion.


Assuntos
Fenômenos Fisiológicos Bacterianos , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Guanosina Pentafosfato/metabolismo , Estresse Fisiológico , Bactérias/genética , Plasticidade Celular , Redes Reguladoras de Genes , Homeostase , Redes e Vias Metabólicas , Anotação de Sequência Molecular , Nitrogênio , Fosfatos/metabolismo , Desenvolvimento Vegetal , Plantas , Solo , Estresse Fisiológico/genética
16.
Microbiol Res ; 227: 126303, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421717

RESUMO

The inhibitory action that a Brevibacillus laterosporus strain isolated from the honeybee body causes against the American Foulbrood (AFB) etiological agent Paenibacillus larvae was studied by in-vitro experiments. A protein fraction isolated from B. laterosporus culture supernatant was involved in the observed inhibition of P. larvae vegetative growth and spore germination. As a result of LC-MS/MS proteomic analyses, the bacteriocin laterosporulin was found to be the major component of this fraction, followed by other antimicrobial proteins and substances including lectins, chaperonins, various enzymes and a number of putative uncharacterized proteins. The results obtained in this study highlight the potential of B. laterosporus as a biological control agent for preserving and improving honeybee health.


Assuntos
Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/farmacologia , Abelhas/microbiologia , Brevibacillus/metabolismo , Paenibacillus larvae/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Brevibacillus/isolamento & purificação , Cromatografia Líquida , Testes de Sensibilidade Microbiana , Proteômica , Espectrometria de Massas em Tandem
17.
J Agric Food Chem ; 67(37): 10373-10379, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31453692

RESUMO

Agarose can be hydrolyzed into agarooligosaccharides (AOSs) by α-agarase, which is an important enzyme for efficient saccharification of agarose or preparation of bioactive oligosaccharides from agarose. Although many ß-agarases have been reported and characterized, there are only a few studies on α-agarases. Here, we cloned a novel α-agarase named CaLJ96 with a molecular weight of approximately 200 kDa belonging to glycoside hydrolase family 96 from Catenovulum agarivorans. CaLJ96 has good pH stability and exhibits maximum activity at 37 °C and pH 7.0. The hydrolyzed products of agarose by CaLJ96 are analyzed as agarobiose (A2), agarotetraose (A4), and agarohexaose (A6), in which A4 is the dominant product. CaLJ96 can hydrolyze agaropentaose (A5) into A2 and agarotriose (A3) and A6 into A2 and A4 but cannot act on A2, A3, or A4. This is the first report to characterize the α-agarase action on AOSs in detail. Therefore, CaLJ96 has potential for the manufacture of bioactive AOSs.


Assuntos
Alteromonadaceae/enzimologia , Proteínas de Bactérias/química , Glicosídeo Hidrolases/química , Alteromonadaceae/química , Alteromonadaceae/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Estabilidade Enzimática , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Peso Molecular , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Sefarose/química , Sefarose/metabolismo , Especificidade por Substrato
18.
J Agric Food Chem ; 67(37): 10392-10400, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31461615

RESUMO

The specificity of fructooligosaccharides as prebiotics depends on their size and structure, which in turn depend on their origin or the synthesis procedure. In this work we describe the application of an inulosucrase (IslA) from Leuconostoc citreum CW28 to produce high molecular weight inulin from sucrose alongside a commercial endoinulinase (Novozym 960) produced by Aspergillus niger for a simultaneous or sequential reaction to synthesize fructooligosaccharides (FOS). The simultaneous reaction resulted in a higher substrate conversion and a wide diversity of FOS when compared to the sequential reaction. A shotgun MS analysis of the commercial endoinulinase preparation surprisingly revealed an additional enzymatic activity: a fructosyltransferase, responsible for the synthesis of FOS from sucrose. Consequentially, the range of FOS obtained in reactions combining inulosucrase from Ln. citreum with the fructosyltransferase and endoinulinase from A. niger with sucrose as substrate may be extended and regulated.


Assuntos
Proteínas de Bactérias/química , Proteínas Fúngicas/química , Glicosídeo Hidrolases/química , Hexosiltransferases/química , Inulina/química , Leuconostoc/enzimologia , Oligossacarídeos/química , Aspergillus niger/enzimologia , Biocatálise , Sacarose/química
19.
BMC Infect Dis ; 19(1): 678, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370804

RESUMO

BACKGROUND: Fecal colonization with carbapenem-resistant Enterobacteriaceae (CRE) is a risk factor for bacterial translocation resulting in subsequent endogenous infections. The purpose of this study is to investigate the prevalence of CRE strains colonization in stool samples of outpatient in a tertiary pediatric hospital of Shanghai, China. METHODS: In a retrospective study, fecal samples were consecutively obtained from patients in 2016 and screening test for CRE was conducted by using home-made MacConkey agar. Antimicrobial susceptibility was determined by the broth microdilution method and ß-lactamases were characterized by polymerase chain reaction (PCR) assays and DNA sequencing. Multilocus sequence typing (MLST) was performed for the genetic relationships of the isolates. RESULTS: A total of 880 fecal samples were included for this screening test and 32 CRE strains were identified in 32 non-duplicate fecal samples from 32 children (1.3 ± 1.5 years), with a carriage rate of 3.6%. These strains mainly distributed in Klebsiella pnuemoniae (37.5%) and Escherichia coli (37.5%). All CRE strains showed high resistance to most of the routinely used antibiotics (> 90%) except for polymyxin B and tigecycline. The blaNDM gene was the major carbapenemase gene harbored by gastrointestinal CRE strains, followed by blaKPC-2, blaIMP-26, and blaIMP-4. Other ß-Lactamase genes including blaCTX-M, blaSHV, blaTEM-1, and blaDHA-1 were also detected. MLST analysis revealed that various sequence types (STs) were detected in these strains, with ST11 and ST37 being more prevalent in K.pneumoniae and ST101 in E.coli. CONCLUSIONS: This study revealed the prevalence of CRE fecal carriage in children from outpatient and urgent implementation of infection control measure should be conducted to limit the spread of CRE strains.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/patogenicidade , Infecções por Enterobacteriaceae/epidemiologia , Fezes/microbiologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Pré-Escolar , China/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/genética , Feminino , Humanos , Lactente , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Pacientes Ambulatoriais/estatística & dados numéricos , Prevalência , Estudos Retrospectivos , beta-Lactamases/genética
20.
Braz J Infect Dis ; 23(4): 246-253, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421107

RESUMO

Accurate and rapid diagnostic tools are important aspects of managing tuberculosis (TB) cases appropriately. However, the sensitivity and specificity of diagnostic kits based on immune response such as the tuberculin skin test (TST) and interferon gamma release assay (IGRA) are still debated. Thus, the exploration and assessment of specific biomarker-targeted antibodies are needed for the development of an accurate and rapid diagnostic tool. The present study was conducted in patients with a respiratory problem suspected to be TB at Dr. Soetomo Hospital, Surabaya, Indonesia. Among 102 patients tested by GeneXpert and AFB, 59 serum samples were from cases retrospectively determined to have active TB. A total of 102 serum of healthy controls (HC) was also collected. The PPD antigen and the recombinant CFP-10 and ESAT-6 proteins were prepared. Antibody responses against these proteins were evaluated by ELISA. All samples were also screened for the possibility of Mycobacterium avium-intracellulare complex (MAC) infection using Capilla MaC kit. The results showed that TB patients had a significantly higher concentration of IgG antibody in response to PPD than the HC. In addition, the receiver operating characteristic (ROC) curve analysis showed that PPD was acceptable for diagnostic purposes with an AUC value of 0.835 (95% CI 0.770-0.900, p < 0.0001). However, ESAT-6 and CFP-10 had low AUCs, and 32 samples from both groups showed a low concentration of IgA antibody against all antigens. The MAC detection results also showed that the concentration of IgA in the HC group was the highest. The current results indicate that PPD is a better antigen for antibody-based detection of TB than ESAT-6 and CFP-10. Based on the MAC detection assay, 53 people in the HC group were probably infected with rapidly growing nontuberculous mycobacteria (NTM), although antibody response to PPD was low.


Assuntos
Formação de Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculina/imunologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Teste Tuberculínico , Tuberculose Pulmonar/sangue , Adulto Jovem
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