scholarly journals Extracellular Production of Pectinase from Bacteria Isolated from Rotten Apples from Lahore, Pakistan

2019 ◽  
Vol 01 (03) ◽  
pp. 37-45
Author(s):  
Fatima Amanat ◽  
Amna Yaqoob ◽  
Asif Ali ◽  
Muhammad Sajjad
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Serratia Marcescens ◽  
Enzyme Assay ◽  
Bacterial Species ◽  
Enzyme Concentration ◽  
Commercial Production ◽  
Extracellular Production ◽  
Plant Body ◽  
Pectinolytic Activity

Pectins are intricate blends of polysaccharides which make up around 33% of plantcell wall. Despite of their presence in the greater part of plant body and in other sources, commercial production of pectin is extremely difficult. This is a systematic study that aimed to produce pectinase from bacterial species isolated from rotten apple samples. Zymography and enzyme assay through DNS method were performed to check the pectinolytic activity of bacteria isolated from rotten apple samples. Of all five bacterial species (Serratia marcescens, Klebseilla pneumoniea, Pseudomonas aeruginosa and Escherichia coli) maximum enzyme concentration was showed in Pseudomonas aeruginosa and it was 6.2 U/mL. The major achievement of this study was to screen out the most efficient pectinases producing isolate of Serratia marcescens from rotten apples that has never been reported to produce pectinase, previously.

scholarly journals OS PRINCIPAIS FATORES DE RISCO DA PNEUMONIA ASSOCIADA À VENTILAÇÃO MECÂNICA EM UTI ADULTA.

2016 ◽  
Vol 7 (1) ◽  
pp. 80-92
Author(s):  
Janice Barbieri Costa ◽  
Alessandro Alessandro Lima Costa Lima ◽  
Fernanda Torres ◽  
Antônia de Fátima Galdino da Silva ◽  
André Tomaz Terra Júnior
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Serratia Marcescens ◽  
Terapia Intensiva

A pneumonia é uma inflamação do parênquima pulmonar causada por diversos agentes etiológicos, as pneumonias hospitalares são causadas principalmente por Enterobacter, Escherichia coli, Klebsiella, Proteus, Serratia marcescens, Pseudomonas aeruginosa e Staphylococcus aureus. A pneumonia associada à ventilação mecânica (PAVM) é considerada a infecção nosocomial mais frequente em unidades de terapia intensiva (UTI) e é definida como uma inflamação do parênquima pulmonar, que aparece após 48 a 72 horas da intubação endotraqueal e do inicio da ventilação mecânica. O objetivo desse trabalho foi demonstrar os principais fatores de risco para a aquisição da PAVM. A pesquisa de revisão literária se deu através de base de dados, como PubMed e Bireme, LILACS, SciELO, o período de publicação compreenderam os anos de 1998 á 2013. A PAVM possui alguns fatores de risco, que são classificados em modificáveis ou não modificáveis.  Alguns exemplos desses fatores de risco não modificáveis são: idade, gravidade da doença de base, Doença Pulmonar Obstrutiva Crônica (DPOC). E os fatores modificáveis alguns exemplos são: educação continuada dos profissionais sobre os fatores de risco, o estabelecimento de protocolos que evitem o uso indiscriminado de antibióticos. Conclui-se através dessa revisão literária que a maioria dos pacientes internados em UTI está em ventilação mecânica (VM) e que nos pacientes intubados, a incidência de pneumonia é de 7 a 21 vezes mais elevado em relação àqueles que não necessitam de ventiladores e por isso são necessárias medidas preventivas.

scholarly journals N-Acetylcysteine Selectively Antagonizes the Activity of Imipenem in Pseudomonas aeruginosa by an OprD-Mediated Mechanism

2015 ◽  
Vol 59 (6) ◽  
pp. 3246-3251 ◽  
Author(s):  
Jerónimo Rodríguez-Beltrán ◽  
Gabriel Cabot ◽  
Estela Ynés Valencia ◽  
Coloma Costas ◽  
German Bou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Antibiotic Activity ◽  
Simultaneous Treatment ◽  
Content Type ◽  
Sds Page

ABSTRACTThe modulating effect ofN-acetylcysteine (NAC) on the activity of different antibiotics has been studied inPseudomonas aeruginosa. Our results demonstrate that, in contrast to previous reports, only the activity of imipenem is clearly affected by NAC. MIC and checkerboard determinations indicate that the NAC-based modulation of imipenem activity is dependent mainly on OprD. SDS-PAGE of outer membrane proteins (OMPs) after NAC treatments demonstrates that NAC does not modify the expression of OprD, suggesting that NAC competitively inhibits the uptake of imipenem through OprD. Similar effects on imipenem activity were obtained withP. aeruginosaclinical isolates. Our results indicate that imipenem-susceptibleP. aeruginosastrains become resistant upon simultaneous treatment with NAC and imipenem. Moreover, the generality of the observed effects of NAC on antibiotic activity was assessed with two additional bacterial species,Escherichia coliandAcinetobacter baumannii. Caution should be taken during treatments, as the activity of imipenem may be modified by physiologically attainable concentrations of NAC, particularly during intravenous and nebulized regimes.

scholarly journals Studies on Some Biologically Cobalt(II), Copper(II) and Zinc(II) Complexes With ONO, NNO and SNO Donor Pyrazinoylhydrazine-Derived Ligands

1998 ◽  
Vol 5 (5) ◽  
pp. 267-274 ◽  
Author(s):  
Zahid H. Chohan ◽  
Marapaka Praveen ◽  
Syed K. A. Sherazi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Bacterial Species ◽  
Analytical Data ◽  
Biologically Active ◽  
Activity Data ◽  
Distorted Octahedral ◽  
Physicochemical Studies

Biologically active complexes of Co(II), Ni(II), Cu(II) and Zn(II) with novel ONO, NNO and SNO donor pyrazinoylhydrazine-derived compounds have been prepared and characterized on the basis of analytical data and various physicochemical studies. Distorted octahedral structures for all the complexes have been proposed. The synthesized ligands and their complexes have been screened for their antibacterial activity against bacterial species Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumonae. The activity data show the metal complexes to be more active than the parent free ligands against one or more bacterial species.

scholarly journals Improving the Efficacy of Antimicrobials against Biofilm-Embedded Bacteria Using Bovine Hyaluronidase Azoximer (Longidaza®)

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1740
Author(s):  
Elena Trizna ◽  
Diana Baidamshina ◽  
Anna Gorshkova ◽  
Valentin Drucker ◽  
Mikhail Bogachev ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Immune System ◽  
Side Effects ◽  
Klebsiella Pneumoniae ◽  
Chronic Infection ◽  
Bacterial Species ◽  
Biofilm Bacteria ◽  
Biofilm Structure

While in a biofilm, bacteria are extremely resistant to both antimicrobials and the immune system, leading to the development of chronic infection. Here, we show that bovine hyaluronidase fused with a copolymer of 1,4-ethylenepiperazine N-oxide and (N-carboxymethyl) -1,4-ethylenepiperazinium bromide (Longidaza®) destroys both mono- and dual-species biofilms formed by various bacteria. After 4 h of treatment with 750 units of the enzyme, the residual biofilms of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae preserved about 50–70% of their initial mass. Biomasses of dual-species biofilms formed by S. aureus and the four latter species were reduced 1.5-fold after 24 h treatment, while the significant destruction of S. aureus–P. aeruginosa and S. aureus–K. pneumoniae was also observed after 4 h of treatment with Longidaza®. Furthermore, when applied in combination, Longidaza® increased the efficacy of various antimicrobials against biofilm-embedded bacteria, although with various increase-factor values depending on both the bacterial species and antimicrobials chosen. Taken together, our data indicate that Longidaza® destroys the biofilm structure, facilitating the penetration of antimicrobials through the biofilm, and in this way improving their efficacy, lowering the required dose and thus also potentially reducing the associated side effects.

scholarly journals Détermination de la sensibilité aux antibiotiques des bactéries isolées de l'environnement du bloc opératoire de l'Hôpital National de Zinder, Niger

2020 ◽  
Vol 15 (2) ◽  
pp. 48-52
Author(s):  
O SiddoFarka ◽  
O Abdoualye ◽  
M Doutchi ◽  
A Biraima ◽  
O Amadou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Serratia Marcescens ◽  
Stenotrophomonas Maltophilia ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Étude Prospective ◽  
Résistance Aux Antibiotiques ◽  
Bacillus Spp

Objectif : Dans un contexte de ressources limitées, la connaissance du profil des germes contaminant les blocs opératoires et leur résistance aux antibiotiques constitue un maillon de la prévention des infections associées aux soins. Ainsi, l'objectif de notre étude était de déterminer la sensibilité aux antibiotiques des bactéries isolées de l'environnement du bloc opératoire de l'Hôpital National de Zinder. Matériels et Méthodes : Nous avions mené une étude prospective, transversale et descriptive de Janvier à Mars 2020. Les prélèvements avaient été réalisés par écouvillonnage le matin avant le début des activités et avaient concerné les mains et blouses des chirurgiens, le matériel de chirurgie et les équipements du bloc opératoire. Nous avions effectué l'isolement, l'identification et l'antibiogramme des souches bactériennes au niveau du laboratoire de biologie par des techniques conventionnelles classiques. Résultats : Au total, 74 prélèvements avaient été effectués. La culture était positive dans 58,10% des cas (43/74). Les bactéries isolées étaient constituées de 25 souches de Bacillus spp (58,13%), 10 souches de bactéries Gram négatif non fermentaires avec Acinetobacter bamanii (14,0%), Pseudomonas aeruginosa (7,0%) et Stenotrophomonas maltophilia (2,3%) et 8 souches d'entérobactéries représentées par Serratia marcescens (4,7%), Enterobacter cloacae (4,7%), Enterobacter aerogenes (4,7%), Escherichia coli (2,3%) et Klebsiella pneumoniae (2,3%).Concernant la sensibilité des souches aux antibiotiques, une seule souche d'Enterobacter aerogenes était résistante à l'Imipenème et 3 des 9 entérobactéries isolées étaient productrices de bétalactamase à spectre élargi. Conclusion : Au vu de résultats de cette étude, il convient de mettre en place des procédures adaptées en vue d'une meilleure surveillance microbiologique des blocs opératoires. Cela contribuera sans doute à la prévention des infections associées aux soins.

Reliability of Disc Diffusion Susceptibility Testing

1982 ◽  
Vol 3 (3) ◽  
pp. 230-237 ◽  
Author(s):  
Patrick R. Murray ◽  
Jacquelyn R. Zeitinger ◽  
Donald J. Krogstad
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Serratia Marcescens ◽  
Linear Relationship ◽  
Susceptibility Testing ◽  
Disc Diffusion ◽  
Diffusion Technique

AbstractWe retested 2,181 bacteria-antibiotic combinations with the Kirby-Bauer disc-diffusion technique and found interpretive changes with 120 (5.5%). Most changes (101 of 120) were single steps (i.e. from R to I, I to R or S, or S to I). Of the 19 remaining, 10 of them were from R to Sand nine from S to R. These changes were significantly more frequent for combinations with zone diameters clustered near interpretive breakpoints (within 2mm) than for other combinations, and there was a linear relationship between decreased reproducibility and increased clustering near interpretive breakpoints.Based on an analysis of all susceptibility testing results performed in 1978, combinations most commonly clustered near interpretive breakpoints included: Ampicillin with Klebsiella pneumoniae; erythromycin with enterococci; chloramphenicol with Serratia marcescens; gentamicin with Pseudomonas aeruginosa and enterocci; and tetracycline with Enterobacter spp., Escherichia coli, and K. pneumoniae.

scholarly journals Methionine Limitation Impairs Pathogen Expansion and Biofilm Formation Capacity

2019 ◽  
Vol 85 (9) ◽  
Author(s):  
A. Jochim ◽  
T. Shi ◽  
D. Belikova ◽  
S. Schwarz ◽  
A. Peschel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Human Serum ◽  
Bacterial Infections ◽  
Bacterial Species ◽  
Biosynthesis Pathway ◽  
Methionine Biosynthesis ◽  
Content Type

ABSTRACTMultidrug-resistant bacterial pathogens are becoming increasingly prevalent, and novel strategies to treat bacterial infections caused by these organisms are desperately needed. Bacterial central metabolism is crucial for catabolic processes and provides precursors for anabolic pathways, such as the biosynthesis of essential biomolecules like amino acids or vitamins. However, most essential pathways are not regarded as good targets for antibiotic therapy since their products might be acquired from the environment. This issue raises doubts about the essentiality of such targets during infection. A putative target in bacterial anabolism is the methionine biosynthesis pathway. In contrast to humans, almost all bacteria carry methionine biosynthesis pathways which have often been suggested as putative targets for novel anti-infectives. While the growth of methionine auxotrophic strains can be stimulated by exogenous methionine, the extracellular concentrations required by most bacterial species are unknown. Furthermore, several phenotypic characteristics of methionine auxotrophs are only partly reversed by exogenous methionine. We investigated methionine auxotrophic mutants ofStaphylococcus aureus,Pseudomonas aeruginosa, andEscherichia coli(all differing in methionine biosynthesis enzymes) and found that each needed concentrations of exogenous methionine far exceeding that reported for human serum (∼30 µM). Accordingly, these methionine auxotrophs showed a reduced ability to proliferate in human serum. Additionally,S. aureusandP. aeruginosamethionine auxotrophs were significantly impaired in their ability to form and maintain biofilms. Altogether, our data show intrinsic defects of methionine auxotrophs. This result suggests that the pathway should be considered for further studies validating the therapeutic potential of inhibitors.IMPORTANCENew antibiotics that attack novel targets are needed to circumvent widespread resistance to conventional drugs. Bacterial anabolic pathways, such as the enzymes for biosynthesis of the essential amino acid methionine, have been proposed as potential targets. However, the eligibility of enzymes in these pathways as drug targets is unclear because metabolites might be acquired from the environment to overcome inhibition. We investigated the nutritional needs of methionine auxotrophs of the pathogensStaphylococcus aureus,Pseudomonas aeruginosa, andEscherichia coli. We found that each auxotrophic strain retained a growth disadvantage at methionine concentrations mimicking those availablein vivoand showed that biofilm biomass was strongly influenced by endogenous methionine biosynthesis. Our experiments suggest that inhibition of the methionine biosynthesis pathway has deleterious effects even in the presence of external methionine. Therefore, additional efforts to validate the effects of methionine biosynthesis inhibitorsin vivoare warranted.

scholarly journals fleQ, the Gene Encoding the Major Flagellar Regulator of Pseudomonas aeruginosa, Is σ70 Dependent and Is Downregulated by Vfr, a Homolog of Escherichia coli Cyclic AMP Receptor Protein

2002 ◽  
Vol 184 (19) ◽  
pp. 5240-5250 ◽  
Author(s):  
Nandini Dasgupta ◽  
Evan P. Ferrell ◽  
Kristen J. Kanack ◽  
Susan E. H. West ◽  
Reuben Ramphal
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Binding Site ◽  
Caulobacter Crescentus ◽  
Bacterial Species ◽  
Consensus Sequence ◽  
In Vitro Transcription ◽  
Receptor Protein ◽  
Regulatory Cascade

ABSTRACT The flagellar transcriptional regulator FleQ appears to be the highest-level regulator in the hierarchical regulatory cascade of flagellar biogenesis in Pseudomonas aeruginosa. Except for the posttranslational downregulation of FleQ activity by FleN, an antiactivator, not much is known about the regulation of the fleQ gene or its gene product. Some FleQ homologs in other bacterial species either are positively regulated by another regulator (e.g., CtrA, the master regulator regulating FlbD in Caulobacter crescentus) or are expressed from a σ70-dependent promoter (e.g., FlgR of Helicobacter pylori). In this study we demonstrated that Vfr, an Escherichia coli CRP homolog known to function as an activator for various genes, including lasR, regA, and toxA, in P. aeruginosa, is capable of repressing fleQ transcription by binding to its consensus sequence in the fleQ promoter. In a DNase I footprint assay, purified Vfr protected the sequence 5′-AATTGACTAATCGTTCACATTTG-3′. When this putative Vfr binding site in the fleQ promoter was mutated, Vfr was unable to bind the fleQ promoter fragment and did not repress fleQ transcription effectively. Primer extension analysis of the fleQ transcript revealed two transcriptional start sites, t1 and t2, that map within the Vfr binding site. A putative −10 region (TAAAAT) for the t2 transcript, with a five-of-six match with the E. coli σ70 binding consensus, overlaps with one end of the Vfr binding site. A 4-bp mutation and an 8-bp mutation in this −10 region markedly reduced the activity of the fleQ promoter. The same mutations led to the disappearance of the 203-nucleotide fleQ transcript in an in vitro transcription assay. Vfr probably represses fleQ transcription by binding to the Vfr binding site in the fleQ promoter and preventing the sigma factor from binding to the −10 region to initiate transcription.

scholarly journals Surfing Motility: a Conserved yet Diverse Adaptation among Motile Bacteria

2018 ◽  
Vol 200 (23) ◽  
Author(s):  
Evelyn Sun ◽  
Sijie Liu ◽  
Robert E. W. Hancock
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Broad Spectrum ◽  
Proteus Mirabilis ◽  
Salmonella Enterica ◽  
Bacterial Species ◽  
Content Type ◽  
Adaptive Resistance ◽  
Sensing Systems

ABSTRACTBacterial rapid surfing motility is a novel surface adaptation ofPseudomonas aeruginosain the presence of the glycoprotein mucin. Here, we show that other Gram-negative motile bacterial species, includingEscherichia coli,Salmonella enterica,Vibrio harveyi,Enterobacter cloacae, andProteus mirabilis, also exhibit the physical characteristics of surfing on the surface of agar plates containing 0.4% mucin, where surfing motility was generally more rapid and less dependent on medium viscosity than was swimming motility. As previously observed inPseudomonas aeruginosa, all surfing species exhibited some level of broad-spectrum adaptive resistance, although the antibiotics to which they demonstrated surfing-mediated resistance differed. Surfing motility inP. aeruginosawas found to be dependent on the quorum-sensing systems of this organism; however, this aspect was not conserved in other tested bacterial species, includingV. harveyiandS. enterica, as demonstrated by assaying specific quorum-sensing mutants. Thus, rapid surfing motility is a complex surface growth adaptation that is conserved in several motile bacteria, involves flagella, and leads to diverse broad-spectrum antibiotic resistance, but it is distinct in terms of dependence on quorum sensing.IMPORTANCEThis study showed for the first time that surfing motility, a novel form of surface motility first discovered inPseudomonas aeruginosaunder artificial cystic fibrosis conditions, including the presence of high mucin content, is conserved in other motile bacterial species known to be mucosa-associated, includingEscherichia coli,Salmonella enterica, andProteus mirabilis. Here, we demonstrated that key characteristics of surfing, including the ability to adapt to various viscous environments and multidrug adaptive resistance, are also conserved. Using mutagenesis assays, we also identified the importance of all three known quorum-sensing systems, Las, Rhl, and Pqs, inP. aeruginosain regulating surfing motility, and we also observed a conserved dependence of surfing on flagella in certain species.

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