scholarly journals Diarréia em bezerros da raça Nelore criados extensivamente: estudo clínico e etiológico

2007 ◽  
Vol 27 (10) ◽  
pp. 419-424 ◽  
Author(s):  
José P. Oliveira Filho ◽  
Daniel P.G. Silva ◽  
Marcelo D. Pacheco ◽  
Luciene M. Mascarini ◽  
Marcio G. Ribeiro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Spp ◽  
E Coli ◽  
Cryptosporidium Spp

A diarréia é considerada uma das principais causas de morbidade e mortalidade de bezerros neonatos. Foram colhidas 100 amostras fecais diarréicas e 30 amostras não diarréicas (grupo controle), de bezerros Nelore com até nove semanas de idade com o objetivo de detectar os enteropatógenos Salmonella spp., Escherichia coli, rotavírus, coronavírus, Cryptosporidium spp. e ovos de helmintos. Enteropatógenos foram detectados em 79,0% das amostras diarréicas e em 70,0% das amostras não-diarréicas. No grupo de bezerros com diarréia, E. coli (69,0%) foi o agente mais freqüentemente isolado, seguido de Cryptosporidium spp. (30,0%), coronavírus (16,0%) e rotavírus (11,0%). No grupo controle, E. coli, Cryptosporidium spp. e coronavírus foram detectados, respectivamente, em 66,7%, 10,0% e 3,3% das amostras. Salmonella spp. e ovos de estrongilídeos não foram encontrados nos dois grupos avaliados. A fímbria K99 foi identificada exclusivamente nas linhagens de E. coli isoladas de bezerros com diarréia (5,8%). Entre os antimicrobianos avaliados "in vitro" a enrofloxacina, a norfloxacina e a gentamicina foram os mais efetivos. O peso dos bezerros aos 210 dias de idade não apresentou diferença significativa entre os animais com e sem diarréia.

scholarly journals Research of Salmonella spp. and evaluation of pathogenicity, cytotoxicity of Escherichia coli isolates proceeding from sparrows (Passer domesticus)

2012 ◽  
Vol 32 (9) ◽  
pp. 931-935 ◽  
Author(s):  
Sineide M.O. Vilela ◽  
José W. Pinheiro Júnior ◽  
José S.A. Silva ◽  
Fernanda de Pace ◽  
Wanderley D. Silveira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Phylogenetic Profile ◽  
Passer Domesticus ◽  
Vero Cells ◽  
Pathogenicity Test ◽  
Salmonella Spp ◽  
E Coli

The aim of this study was to research the occurrence of Salmonella spp. and Escherichia coli in feces samples of sparrows, as well as to identify the pathogenicity, cytotoxicity and sensitivity profile of the isolates to antimicrobial use. Two hundred and twenty eight sparrows were captured in eight farms. The in vitro pathogenicity test was performed by the isolates culture on congo red-magnesium oxalate Agar, whilst the in vivo pathogenicity test was performed in one day-old chicks. In order to study the cytotoxic effects of indicators, samples were inoculated into Vero cells. The results obtained for Escherichia coli isolation confirmed the presence of this microorganism in 30 (13.2%) of the evaluated samples. Out of those isolates, 10 (33.3%) presented the capacity of absorbing ongo red. As for in vivo pathogenicity a 68.0% of mortality rate of the evaluated samples was observed. Out of 20 isolates tested for cytotoxin production, none of them presented cytotoxic effect in the Vero cells. The Salmonella spp was isolated only in one sample (0.04%), and it was identified as Salmonella enterica subspecies houtenae. Results obtained through this research indicate the need for new studies to identify other virulence factors of E. coli samples and to delineate the phylogenetic profile of the isolates in order to establish a relation with colibacillosis outbreaks in chickens and broilers in the studied region, as well as to analyze the critical points in the aviculture productive chain to identify the source of Salmonella enterica subspecies houtenae.

scholarly journals The occurrence and prevalence of potentially zoonotic enteropathogens in

Rangifer ◽  
2004 ◽  
Vol 24 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Nicole Kemper ◽  
Ansgar Aschfalk ◽  
Christiane Höller
Keyword(s):  
Escherichia Coli ◽  
Health Risk ◽  
Rangifer Tarandus ◽  
Intestinal Flora ◽  
Salmonella Spp ◽  
E Coli ◽  
Cryptosporidium Spp ◽  
Enteropathogenic Bacteria ◽  
Enterococcus Spp ◽  
Campylobacter Spp

The information about pathogens excreted by semi-domesticated reindeer (Rangifer tarandus tarandus) that might represent a health risk to humans and animals is insufficient. The objectives of this study are to find the occurrence and prevalence of important potentially enteropathogenic, zoonotic bacteria and parasites in reindeer. Faecal samples from clinically healthy, semi-domesticated reindeer (n=2243) from northern regions of Finland and Norway were examined for important potentially enteropathogenic bacteria (Campylobacter spp., Enterococcus spp., Escherichia coli, Salmonella spp. and Yersinia spp.) and parasites (Cryptosporidium spp.) following standard procedures. Escherichia coli were isolated in 2123 (94.7%), Enterococcus spp. in 2084 (92.9%), Yersinia spp. in 108 (4.8%) samples and Campylobacter sp., identified as C. hyointestinalis, in one sample only (0.04%). Neither Salmonella spp. nor Cryptosporidium-oocysts were detected. This study clearly shows that E. coli and Enterococcus spp. belong to the normal intestinal flora of healthy reindeer. However, only few of the isolated E. coli-strains possess genes encoding stx1 (0.14%), stx2 (0%), eae (0.52%) and hlyEHEC (0.99%), detected by PCR, that have the ability to cause health problems in humans and also animals. The isolated Yersinia spp. were further analysed for virulence factors, but examinations revealed no pathogenic strains. The public health risk due to excretion of important enteropathogenic microorganisms from reindeer has to be considered very low at present but a putative epidemiological threat to human health might arise when herding conditions are changed towards intensification and crowding. This study was performed as part of the EU-project RENMAN (www.urova.fi/home/renman/). Abstract in Norwegian / Sammendrag: Det er mangelfull kunnskap om hvorvidt det i reinmøkk kan finnes mikroorganismer som kan representere en helserisiko for dyr og mennesker. Hensikten med denne studien var å undersøke forekomsten av mulige sykdomsfremkallende mikroorganismer i reinmøkk. Prøver av reinmøkk ble samlet fra 2243 klinisk friske tamrein i nordre deler av Finland og Norge. Prøvene ble undersøkt for bakteriene Campylobacter spp., Enterococcus spp., Escherichia coli, Salmonella spp., Yersinia spp. og parasitten Cryptosporidium spp. ved bruk av standardiserte laboratoriemetoder. E. coli ble funnet i 2123 prøver (94,7%), Enterococcus spp. i 2084 prøver (92,9%) og Yersinia spp. i 108 prøver (4,8%). Campylobacter spp., identifisert som Campylobacter hyointestinalis, ble bare funnet i én prøve (0,04%). Salmonella spp. og Cryptosporidium spp. ble ikke påvist. Videre undersøkelser av E. coli viste at bare svært få (<1%) av isolatene hadde gener som kodet for mulige sykdomsfremkallende toksiner. Videre undersøkelser av Yersinia spp. viste at ingen av disse isolatene var sykdomsfremkallende. Studien viser at helserisikoen knyttet til de undersøkte mikroorganismene i reinmøkk må betraktes som svært liten.

scholarly journals Etiology of acute diarrhea among children in Ribeirão Preto-SP, Brazil

2001 ◽  
Vol 43 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Marta Inês Cazentini MEDEIROS ◽  
Suzel Nogueira NEME ◽  
Paulo da SILVA ◽  
Divani Maria CAPUANO ◽  
Maria Clarice ERRERA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acute Diarrhea ◽  
Acute Gastroenteritis ◽  
Salmonella Spp ◽  
Standard Methods ◽  
E Coli ◽  
Cryptosporidium Spp ◽  
Shigella Spp ◽  
Campylobacter Spp

To study the main enteropathogens causing diarrhea in the region of Ribeirão Preto regarding serogroups and serotypes, the feces of 1836 children under 10 years old, from both sexes, attack of acute gastroenteritis, were analysed during a period of 4 years in Adolfo Lutz Institute - Ribeirão Preto, SP. The pathogens identified by standard methods were the following: Escherichia coli, Salmonella spp., Shigella spp., Campylobacter spp., Yersinia spp., and Cryptosporidium spp. Positive samples were 22.8% (419) with 1.7% association of pathogens. Larger isolates were mainly from children 0 to 11 months old. Enteropathogenic E. coli (EPEC) was most frequent (8.7%) with predominance of serogroup O119 (40.2%), followed by Shigella (6.2%), 63.6% of which S. sonnei.

Substituted 4-Formyl-2H-chromen-2-ones: Their Reaction with N-(2,3,4,6-Tetra-Oacetyl- β-D-galactopyranosyl)thiosemicarbazide, Antibacterial and Antifungal Activity of Their Thiosemicarbazone Products

2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Selenium Dioxide ◽  
Antibacterial And Antifungal Activity ◽  
E Coli ◽  
Antibacterial And Antifungal Activities ◽  
Alkyl Ethers ◽  
Antibacterial And Antifungal

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).

scholarly journals In vitro activity of antimicrobial peptide CDP-B11 alone and in combination with colistin against colistin-resistant and multidrug-resistant Escherichia coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaitlin S. Witherell ◽  
Jason Price ◽  
Ashok D. Bandaranayake ◽  
James Olson ◽  
Douglas R. Call
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptide ◽  
Membrane Integrity ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
E Coli ◽  
Minimal Media

AbstractMultidrug-resistant bacteria are a growing global concern, and with increasingly prevalent resistance to last line antibiotics such as colistin, it is imperative that alternative treatment options are identified. Herein we investigated the mechanism of action of a novel antimicrobial peptide (CDP-B11) and its effectiveness against multidrug-resistant bacteria including Escherichia coli #0346, which harbors multiple antibiotic-resistance genes, including mobilized colistin resistance gene (mcr-1). Bacterial membrane potential and membrane integrity assays, measured by flow cytometry, were used to test membrane disruption. Bacterial growth inhibition assays and time to kill assays measured the effectiveness of CDP-B11 alone and in combination with colistin against E. coli #0346 and other bacteria. Hemolysis assays were used to quantify the hemolytic effects of CDP-B11 alone and in combination with colistin. Findings show CDP-B11 disrupts the outer membrane of E. coli #0346. CDP-B11 with colistin inhibits the growth of E. coli #0346 at ≥ 10× lower colistin concentrations compared to colistin alone in Mueller–Hinton media and M9 media. Growth is significantly inhibited in other clinically relevant strains, such as Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae. In rich media and minimal media, the drug combination kills bacteria at a lower colistin concentration (1.25 μg/mL) compared to colistin alone (2.5 μg/mL). In minimal media, the combination is bactericidal with killing accelerated by up to 2 h compared to colistin alone. Importantly, no significant red blood hemolysis is evident for CDP-B11 alone or in combination with colistin. The characteristics of CDP-B11 presented here indicate that it can be used as a potential monotherapy or as combination therapy with colistin for the treatment of multidrug-resistant infections, including colistin-resistant infections.

scholarly journals Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

scholarly journals A Rhodobacter sphaeroides Protein Mechanistically Similar to Escherichia coli DksA Regulates Photosynthetic Growth

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Christopher W. Lennon ◽  
Kimberly C. Lemmer ◽  
Jessica L. Irons ◽  
Max I. Sellman ◽  
Timothy J. Donohue ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structure Function ◽  
Rhodobacter Sphaeroides ◽  
Fatty Acid Content ◽  
Regulatory Protein ◽  
Growth Conditions ◽  
Globular Domain ◽  
Content Type ◽  
E Coli

ABSTRACTDksA is a global regulatory protein that, together with the alarmone ppGpp, is required for the “stringent response” to nutrient starvation in the gammaproteobacteriumEscherichia coliand for more moderate shifts between growth conditions. DksA modulates the expression of hundreds of genes, directly or indirectly. Mutants lacking a DksA homolog exhibit pleiotropic phenotypes in other gammaproteobacteria as well. Here we analyzed the DksA homolog RSP2654 in the more distantly relatedRhodobacter sphaeroides, an alphaproteobacterium. RSP2654 is 42% identical and similar in length toE. coliDksA but lacks the Zn finger motif of theE. coliDksA globular domain. Deletion of the RSP2654 gene results in defects in photosynthetic growth, impaired utilization of amino acids, and an increase in fatty acid content. RSP2654 complements the growth and regulatory defects of anE. colistrain lacking thedksAgene and modulates transcriptionin vitrowithE. coliRNA polymerase (RNAP) similarly toE. coliDksA. RSP2654 reduces RNAP-promoter complex stabilityin vitrowith RNAPs fromE. coliorR. sphaeroides, alone and synergistically with ppGpp, suggesting that even though it has limited sequence identity toE. coliDksA (DksAEc), it functions in a mechanistically similar manner. We therefore designate the RSP2654 protein DksARsp. Our work suggests that DksARsphas distinct and important physiological roles in alphaproteobacteria and will be useful for understanding structure-function relationships in DksA and the mechanism of synergy between DksA and ppGpp.IMPORTANCEThe role of DksA has been analyzed primarily in the gammaproteobacteria, in which it is best understood for its role in control of the synthesis of the translation apparatus and amino acid biosynthesis. Our work suggests that DksA plays distinct and important physiological roles in alphaproteobacteria, including the control of photosynthesis inRhodobacter sphaeroides. The study of DksARsp, should be useful for understanding structure-function relationships in the protein, including those that play a role in the little-understood synergy between DksA and ppGpp.

scholarly journals Enhancement of the Efficiency of Secretion of Heterologous Lipase in Escherichia coli by Directed Evolution of the ABC Transporter System

2005 ◽  
Vol 71 (7) ◽  
pp. 3468-3474 ◽  
Author(s):  
Gyeong Tae Eom ◽  
Jae Kwang Song ◽  
Jung Hoon Ahn ◽  
Yeon Soo Seo ◽  
Joon Shick Rhee
Keyword(s):  
Escherichia Coli ◽  
Directed Evolution ◽  
Abc Transporter ◽  
Microtiter Plate ◽  
Single Amino Acid ◽  
Wild Type ◽  
E Coli ◽  
Single Amino Acid Change ◽  
Secretion Efficiency

ABSTRACT The ABC transporter (TliDEF) from Pseudomonas fluorescens SIK W1, which mediated the secretion of a thermostable lipase (TliA) into the extracellular space in Escherichia coli, was engineered using directed evolution (error-prone PCR) to improve its secretion efficiency. TliD mutants with increased secretion efficiency were identified by coexpressing the mutated tliD library with the wild-type tliA lipase in E. coli and by screening the library with a tributyrin-emulsified indicator plate assay and a microtiter plate-based assay. Four selected mutants from one round of error-prone PCR mutagenesis, T6, T8, T24, and T35, showed 3.2-, 2.6-, 2.9-, and 3.0-fold increases in the level of secretion of TliA lipase, respectively, but had almost the same level of expression of TliD in the membrane as the strain with the wild-type TliDEF transporter. These results indicated that the improved secretion of TliA lipase was mediated by the transporter mutations. Each mutant had a single amino acid change in the predicted cytoplasmic regions in the membrane domain of TliD, implying that the corresponding region of TliD was important for the improved and successful secretion of the target protein. We therefore concluded that the efficiency of secretion of a heterologous protein in E. coli can be enhanced by in vitro engineering of the ABC transporter.

scholarly journals In vitro reconstitution of the GTPase-associated centre of the archaebacterial ribosome: the functional features observed in a hybrid form with Escherichia coli 50S subunits

2006 ◽  
Vol 396 (3) ◽  
pp. 565-571 ◽  
Author(s):  
Takaomi Nomura ◽  
Kohji Nakano ◽  
Yasushi Maki ◽  
Takao Naganuma ◽  
Takashi Nakashima ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Synthetic Activity ◽  
23S Rrna ◽  
Elongation Factors ◽  
Hybrid Form ◽  
Pyrococcus Horikoshii ◽  
E Coli ◽  
Functional Features

We cloned the genes encoding the ribosomal proteins Ph (Pyrococcus horikoshii)-P0, Ph-L12 and Ph-L11, which constitute the GTPase-associated centre of the archaebacterium Pyrococcus horikoshii. These proteins are homologues of the eukaryotic P0, P1/P2 and eL12 proteins, and correspond to Escherichia coli L10, L7/L12 and L11 proteins respectively. The proteins and the truncation mutants of Ph-P0 were overexpressed in E. coli cells and used for in vitro assembly on to the conserved domain around position 1070 of 23S rRNA (E. coli numbering). Ph-L12 tightly associated as a homodimer and bound to the C-terminal half of Ph-P0. The Ph-P0·Ph-L12 complex and Ph-L11 bound to the 1070 rRNA fragments from the three biological kingdoms in the same manner as the equivalent proteins of eukaryotic and eubacterial ribosomes. The Ph-P0·Ph-L12 complex and Ph-L11 could replace L10·L7/L12 and L11 respectively, on the E. coli 50S subunit in vitro. The resultant hybrid ribosome was accessible for eukaryotic, as well as archaebacterial elongation factors, but not for prokaryotic elongation factors. The GTPase and polyphenylalanine-synthetic activity that is dependent on eukaryotic elongation factors was comparable with that of the hybrid ribosomes carrying the eukaryotic ribosomal proteins. The results suggest that the archaebacterial proteins, including the Ph-L12 homodimer, are functionally accessible to eukaryotic translation factors.

scholarly journals Promiscuous Cross-seeding between Bacterial Amyloids Promotes Interspecies Biofilms

2012 ◽  
Vol 287 (42) ◽  
pp. 35092-35103 ◽  
Author(s):  
Yizhou Zhou ◽  
Daniel Smith ◽  
Bryan J. Leong ◽  
Kristoffer Brännström ◽  
Fredrik Almqvist ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shewanella Oneidensis ◽  
Bacterial Attachment ◽  
Surface Attachment ◽  
E Coli ◽  
Amyloid Aggregates ◽  
Functional Amyloids ◽  
Biofilm Development ◽  
Distant Homolog

Amyloids are highly aggregated proteinaceous fibers historically associated with neurodegenerative conditions including Alzheimers, Parkinsons, and prion-based encephalopathies. Polymerization of amyloidogenic proteins into ordered fibers can be accelerated by preformed amyloid aggregates derived from the same protein in a process called seeding. Seeding of disease-associated amyloids and prions is highly specific and cross-seeding is usually limited or prevented. Here we describe the first study on the cross-seeding potential of bacterial functional amyloids. Curli are produced on the surface of many Gram-negative bacteria where they facilitate surface attachment and biofilm development. Curli fibers are composed of the major subunit CsgA and the nucleator CsgB, which templates CsgA into fibers. Our results showed that curli subunit homologs from Escherichia coli, Salmonella typhimurium LT2, and Citrobacter koseri were able to cross-seed in vitro. The polymerization of Escherichia coli CsgA was also accelerated by fibers derived from a distant homolog in Shewanella oneidensis that shares less than 30% identity in primary sequence. Cross-seeding of curli proteins was also observed in mixed colony biofilms with E. coli and S. typhimurium. CsgA was secreted from E. coli csgB− mutants assembled into fibers on adjacent S. typhimurium that presented CsgB on its surfaces. Similarly, CsgA was secreted by S. typhimurium csgB− mutants formed curli on CsgB-presenting E. coli. This interspecies curli assembly enhanced bacterial attachment to agar surfaces and supported pellicle biofilm formation. Collectively, this work suggests that the seeding specificity among curli homologs is relaxed and that heterogeneous curli fibers can facilitate multispecies biofilm development.

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