Serological, Enterotoxin-Producing and Biochemical Properties of Escherichia Coli Isolated from Piglets with Neonatal Diarrhea in Norway

The gene encoding a putative high-potential iron–sulfur protein (HiPIP) from the strictly acidophilic and chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 33020 has been cloned and sequenced. This potential HiPIP was overproduced in the periplasm of the neutrophile and heterotroph Escherichia coli. As shown by optical and EPR spectra and by electrochemical studies, the recombinant protein has all the biochemical properties of a HiPIP, indicating that the iron–sulfur cluster was correctly inserted. Translocation of this protein in the periplasm of E. coli was not detected in a ΔtatC mutant, indicating that it is dependent on the Tat system. The genetic organization of the iro locus in strains ATCC 23270 and ATCC 33020 is different from that found in strains Fe-1 and BRGM. Indeed, in A. ferrooxidans ATCC 33020 and ATCC 23270 (the type strain), iro was not located downstream from purA but was instead downstream from petC2, encoding cytochrome c 1 from the second A. ferrooxidans cytochrome bc 1 complex. These findings underline the genotypic heterogeneity within the A. ferrooxidans species. The results suggest that Iro transfers electrons from a cytochrome bc 1 complex to a terminal oxidase, as proposed for the HiPIP in photosynthetic bacteria.

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Antimicrobial Resistance Profiles and Characterization of Escherichia coli Strains from Cases of Neonatal Diarrhea in Spanish Pig Farms

Veterinary Sciences ◽

10.3390/vetsci7020048 ◽

2020 ◽

Vol 7 (2) ◽

pp. 48

Author(s):

Anna Vidal ◽

Laia Aguirre ◽

Chiara Seminati ◽

Montse Tello ◽

Noelia Redondo ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Animal Health ◽

Phenotypic Analysis ◽

Low Frequencies ◽

Neonatal Diarrhea ◽

E Coli ◽

Pig Farms ◽

Diagnostic Approaches ◽

Low Prevalence

Escherichia coli is considered one of the most common agents associated with neonatal diarrhea in piglets. The aim of this work was to characterize the pathogenic and antimicrobial resistance (AMR) profiles of 122 E. coli strains isolated from pigs suffering diarrhea (n = 94) and pigs without diarrhea (n = 28) of 24 farms in Spain. Virulence factors, toxins and AMR (ESBL and colistin) genes and AMR phenotypes of E. coli isolates were analyzed. Low prevalence of pathogenic E. coli strains (26%) was found in both groups. However, ETEC and VTEC strains were more frequently isolated from diarrheic piglets. Irrespectively of diarrhea occurrence, 97.5% of the strains showed a multidrug-resistance (MDR) profile to aminopenicillins, sulfonamides and tetracyclines. It was found that 22% of E. coli was CTX-M+, with CTX-M-14 being the principal allelic variant. Remarkably, 81.5% of CTX-M+ strains were isolated from diarrheic animals and presented an extended MDR profile to aminopenicillins, quinolones and aminoglycosides. Finally, low frequencies of colistin resistance genes mcr-1 (4/122) and mcr-4 (1/122) were found. MDR E. coli strains are circulating in pig farms of Spain, representing a serious threat to animal and public health. More appropriate diagnostic approaches (genetic and AMR phenotypic analysis) should be implemented in animal health to optimize antibiotic treatments.

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Biogenic Synthesis of AgNPs with Saussurea lappa C.B. Clarke and Studies on Their Biochemical Properties

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2018.16414 ◽

2018 ◽

Vol 18 (12) ◽

pp. 8392-8398 ◽

Cited By ~ 2

Author(s):

Muhammad Riaz ◽

Muhammad Altaf ◽

Amir Faisal ◽

Muhammad Azhar Shekheli ◽

Ghulam Abbass Miana ◽

...

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Inhibition Zone ◽

Xrd Analysis ◽

Biochemical Properties ◽

Root Extract ◽

Biogenic Synthesis ◽

Synthesis Of Nanoparticles ◽

Saussurea Lappa ◽

Drug Candidates

Nanotechnology has become an irreplaceable need and green synthesis of nanoparticles offers several advantages over physical and chemical methods. Medicinal plants are the main reservoirs of drugs and drug candidates. We report the biogenic synthesis of silver nanoparticles (AgNPs) using aqueous root extract of Saussurea lappa. Verification and characterization of these nanoparticles were done by UV-visible spectroscopy, XRD-analysis and Scanning Electron Microscopy and FT-IR. Extract-loaded-AgNPs showed the highest inhibition zone against Escherichia coli (11.0 mm) and intermediate against Pseudomonas aeruginosa (9.0 mm). The methanolic root extract of S. lappa alone, also moderately inhibited Pseudomonas aeruginosa (9.0 mm) and showed lower activity (6.0 mm) against Escherichia coli. Its aqueous roots extract inhibited (6.0 mm) the growth of tested organisms. Methanolic extract showed antioxidant potency (IC50 = 0.814 μg/mL). Experiments revealed the presence of phenols and flavonoids in the roots of Saussurea lappa. These findings provide promising interest to exploit Saussurea lappa for the biogenic synthesis of AgNPs and their biological applications.

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Antimicrobial Resistance Pattern of Escherichia coli Isolated from Frozen Chicken Meat in Bangladesh

Pathogens ◽

10.3390/pathogens9060420 ◽

2020 ◽

Vol 9 (6) ◽

pp. 420 ◽

Cited By ~ 1

Author(s):

Mst. Sonia Parvin ◽

Sudipta Talukder ◽

Md. Yamin Ali ◽

Emdadul Haque Chowdhury ◽

Md. Tanvir Rahman ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Foodborne Pathogens ◽

Biochemical Properties ◽

Chicken Meat ◽

Diffusion Method ◽

Resistance Pattern ◽

Isolation And Identification ◽

E Coli ◽

Encoding Genes

Escherichia coli is known as one of the most important foodborne pathogens in humans, and contaminated chicken meat is an important source of foodborne infection with this bacterium. The occurrence of extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-Ec), in particular, in chicken meat is considered a global health problem. This study aimed to determine the magnitude of E. coli, with special emphasis on ESBL-Ec, along with their phenotypic antimicrobial resistance pattern in frozen chicken meat. The study also focused on the determination of ESBL-encoding genes in E. coli. A total of 113 frozen chicken meat samples were purchased from 40 outlets of nine branded supershops in five megacities in Bangladesh. Isolation and identification of E. coli were done based on cultural and biochemical properties, as well as PCR assay. The resistance pattern was determined by the disc diffusion method. ESBL-encoding genes were determined by multiplex PCR. The results showed that 76.1% of samples were positive for E. coli, of which 86% were ESBL producers. All the isolates were multidrug-resistant (MDR). Resistance to 9–11 and 12–13 antimicrobial classes was observed in 38.4% and 17.4% isolates, respectively, while only 11.6% were resistant to 3–5 classes. Possible extensive drug resistance (pXDR) was found in 2.3% of isolates. High single resistance was observed for oxytetracycline (93%) and amoxicillin (91.9%), followed by ampicillin (89.5%), trimethoprim–sulfamethoxazole, and pefloxacin (88.4%), and tetracycline (84.9%). Most importantly, 89.6% of isolates were resistant to carbapenems. All the isolates were positive for the blaTEM gene. However, the blaSHV and blaCTX-M-2 genes were identified in two ESBL-non producer isolates. None of the isolates carried the blaCTX-M-1 gene. This study provided evidence of the existence of MDR and pXDR ESBL-Ec in frozen chicken meat in Bangladesh, which may pose a risk to human health if the meat is not properly cooked or pickled raw only. This emphasizes the importance of the implementation of good slaughtering and processing practices by the processors.

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E1A 13S and 12S mRNA products made in Escherichia coli both function as nucleus-localized transcription activators but do not directly bind DNA.

Molecular and Cellular Biology ◽

10.1128/mcb.5.10.2653 ◽

1985 ◽

Vol 5 (10) ◽

pp. 2653-2661 ◽

Cited By ~ 77

Author(s):

B Ferguson ◽

B Krippl ◽

O Andrisani ◽

N Jones ◽

H Westphal ◽

...

Keyword(s):

Escherichia Coli ◽

Mammalian Cells ◽

Biochemical Properties ◽

Protein Product ◽

Gene Products ◽

E Coli ◽

Adenovirus E1a ◽

Myc Gene ◽

E1a Gene ◽

Transcription Activators

We previously purified and characterized functionally the Escherichia coli-expressed product of the human subgroup C adenovirus E1A 13S mRNA (B. Ferguson, N. Jones, J. Richter, and M. Rosenberg, Science 224:1343-1346, 1984; B. Krippl, B. Ferguson, M. Rosenberg, and H. Westphal, Proc. Natl. Acad. Sci. USA 81:6988-6992, 1984). We have now expressed in E. coli and purified the protein product encoded by the human subgroup C adenovirus E1A 12S mRNA and have compared the functional properties of this protein with those of the E1A 13S mRNA product. Using microinjection techniques to introduce these proteins into mammalian cells, we found that the E1A 12S mRNA product, like the 13S mRNA product, localized rapidly to the cell nucleus and induced adenovirus gene expression. Although both E1A gene products localized to the nucleus and stimulated adenovirus gene transcription, these proteins did not directly bind to DNA under conditions in which a known DNA-binding protein, the human c-myc gene product, bound DNA efficiently. Thus, the E1A and myc gene products, which have been related both structurally and functionally, exhibit distinctly different biochemical properties.

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Plasmodium falciparum CTP:phosphocholine cytidylyltransferase expressed in Escherichia coli: purification, characterization and lipid regulation

Biochemical Journal ◽

10.1042/bj3240903 ◽

1997 ◽

Vol 324 (3) ◽

pp. 903-910 ◽

Cited By ~ 27

Author(s):

Hye-Jeong YEO ◽

Marie-Pierre LARVOR ◽

Marie-Laure ANCELIN ◽

Henri J. VIAL

Keyword(s):

Escherichia Coli ◽

Plasmodium Falciparum ◽

Oleic Acid ◽

Recombinant Protein ◽

Neutral Lipids ◽

Insoluble Fraction ◽

Biochemical Properties ◽

Ctp:Phosphocholine Cytidylyltransferase ◽

Lipid Regulation

The Plasmodium falciparum CTP:phosphocholine cytidylyltransferase (PfCCT) has been isolated from an overexpressing strain of Escherichia coli. The plasmid pETPfCCT mediated the overexpression of the full-length polypeptide directly. The recombinant protein corresponded to 6–9% of the total cellular proteins and was found essentially in the insoluble membrane fraction. Urea at 6 M was used to solubilize the recombinant protein from the insoluble fraction. The CCT activity was restored upon the removal of urea, and the protein was subsequently purified to homogeneity on a Q-Sepharose column. Approx. 1.4 mg of pure enzyme was obtained from a 250 ml culture of E. coli. Biochemical properties, including in vitro substrate specificity and enzymic characterization, were assessed. The lipid regulation of the recombinant plasmodial CCT activity was characterized for the first time. The Km values were 0.49±0.03 mM (mean±S.E.M.) for phosphocholine and 10.9±0.5 mM for CTP in the presence of lipid activators (oleic acid/egg phosphatidylcholine vesicles), whereas the Km values were 0.66±0.07 mM for phosphocholine and 28.9±0.8 mM for CTP in the absence of lipid activators. The PfCCT activity was stimulated to the same extent in response to egg phosphatidylcholine vesicles containing anionic lipids, such as oleic acid, cardiolipin and phosphatidylglycerol, and was insensitive or slightly sensitive to PC vesicles containing neutral lipids, such as diacylglycerol and monoacylglycerol. Furthermore, the stimulated enzyme activity by oleic acid was antagonized by the cationic aminolipid sphingosine. These lipid-dependence properties place the parasite enzyme intermediately between the mammalian enzymes and the yeast enzyme.

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Matched case-control study evaluating the frequency of the main agents associated with neonatal diarrhea in piglets

Pesquisa Veterinária Brasileira ◽

10.1590/s0100-736x2011000600008 ◽

2011 ◽

Vol 31 (6) ◽

pp. 505-510 ◽

Cited By ~ 10

Author(s):

Ricardo T. Lippke ◽

Sandra M. Borowski ◽

Sandra M.T. Marques ◽

Suelen O. Paesi ◽

Laura L. Almeida ◽

...

Keyword(s):

Escherichia Coli ◽

Clostridium Difficile ◽

Clostridium Perfringens ◽

Case Control Study ◽

Type A ◽

Case Control ◽

Latex Agglutination ◽

Fecal Samples ◽

Neonatal Diarrhea ◽

Control Study

A case-control study was carried out in litters of 1 to 7-day-old piglets to identify the main infectious agents involved with neonatal diarrhea in pigs. Fecal samples (n=276) from piglets were collected on pig farms in the State of Rio Grande do Sul, Brazil, from May to September 2007. Litters with diarrhea were considered cases (n=129) and normal litters (n=147) controls. The samples were examined by latex agglutination test, PAGE, conventional isolating techniques, ELISA, PCR, and microscopic methods in order to detect rotavirus, bacterial pathogens (Escherichia coli, Clostridium perfringens type A and C, and Clostridium difficile), and parasites (Coccidian and Cryptosporidium spp.). Outbreaks of diarrhea were not observed during sampling. At least one agent was detected in fecal samples on 25 out of 28 farms (89.3%) and in 16 farms (57.1%) more than one agent was found. The main agents diagnosed were Coccidia (42.86%) and rotavirus (39.29%). The main agents identified in litters with diarrhea were Clostridium difficile (10.6%), Clostridium perfringens type A (8.8%) and rotavirus (7.5%); in control litters, Clostridium difficile (16.6%) and Coccidian (8.5%). Beta hemolytic Escherichia coli and Clostridium perfringens type C were not detected. When compared with controls, no agent was significantly associated with diarrhea in case litters. These findings stress the need for caution in the interpretation of laboratorial diagnosis of mild diarrhea in neonatal pigs, as the sole detection of an agent does not necessarily indicate that it is the cause of the problem.

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