scholarly journals The effects of oxytetracycline on the intestinalEscherichia coliflora of newly weaned pigs

1985 ◽  
Vol 95 (1) ◽  
pp. 77-85 ◽  
Author(s):  
M. Hinton ◽  
D. J. Hampson ◽  
Elisabeth Hampson ◽  
A. H. Linton
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Agent ◽  
Tetracycline Resistance ◽  
Resistance Pattern ◽  
Selective Isolation ◽  
Weaned Pigs ◽  
Faecal Flora ◽  
Isolation Media ◽  
First Time

SUMMARYFour recently weaned pigs were dosed orally with oxytetracycline. This caused a rapid increase in the incidence of tetracycline resistance (TcR) amongEscherichia coliisolates from the faecal flora. The isolates were differentiated further on the basis of O-serogroup, biotype and resistance pattern. There was no evidence that the administration of the antibiotic selected for a few TcR clones, but rather a relatively large number of TcR strains were identified during the dosing period. Using selective isolation media a proportion of these strains were demonstrated in the minority faecalEsch. coliflora before dosing, while the remainder were recognized for the first time after dosing commenced.The incidence of TcR amongEsch. coliisolates also increased after weaning in other pigs which were not dosed with oxytetracycline or any other antibacterial agent. In a proportion of these animals this increase was associated with the dominance of a TcR enteropathogenic serotype (0149:K 91, K 88a, c) in the faecalEsch. coliflora which was probably ingested in small numbers before weaning. The source of other TcR strains was probably the environment in which each pig was placed after weaning.

scholarly journals Diversity of Tetracycline Resistant Genes in Escherichia coli from Human and Environmental Sources

2016 ◽  
Vol 10 (1) ◽  
pp. 289-300 ◽  
Author(s):  
Saif Al-Bahry ◽  
Nawal Al-Sharji ◽  
Mahmoud Yaish ◽  
Salma Al-Musharafi ◽  
Ibrahim Mahmoud
Keyword(s):  
Escherichia Coli ◽  
Tetracycline Resistance ◽  
Gene Combination ◽  
Treated Sewage ◽  
Maldi Biotyper ◽  
Strict Enforcement ◽  
Resistant Strains ◽  
C 32 ◽  
Treated Sewage Effluent ◽  
First Time

Worldwide tetracycline resistance (Tcr) is increasing dramatically, causing serious environmental and health problems. A total of 201 samples were collected from chicken intestine, human feces and treated sewage effluent (TSE). One hundred and eighteen Escherichia coli strains were isolated and identified using MALDI-Biotyper. Single and multiplex PCR were used to screen isolates for 14 tet genes, among which only 7 tet genes (A, B, C, M, Q, W, 32) were found. Among the resistant isolates, tet A was the most frequent gene, followed by tet B and tet 32 while the rest of tet determinants occurred at a lower frequency. Many strains contained multiple Tcr determinants. Some strains contained 4 tet gene-combination, tet (A/B/C/32) and tet (A/B/M/32). The 4 tet gene combination is reported for the first time in this region. The Tcr isolates showed a high variation of tet gene combination. The increase in the resistance of tetracycline with high diversification is an indication of antibiotics overuse. Strict enforcement of regulation is urgently needed to control and prevent the spread of tetracycline resistant strains which are detrimental to the environment.

scholarly journals Identification and Sequence of a tet(M) Tetracycline Resistance Determinant Homologue in Clinical Isolates of Escherichia coli

2006 ◽  
Vol 188 (20) ◽  
pp. 7151-7164 ◽  
Author(s):  
C. Hal Jones ◽  
Margareta Tuckman ◽  
Ellen Murphy ◽  
Patricia A. Bradford
Keyword(s):  
Escherichia Coli ◽  
Tetracycline Resistance ◽  
Mobile Element ◽  
Clinical Isolates ◽  
Resistance Determinant ◽  
M Gene ◽  
Insertion Element ◽  
E Coli ◽  
Vibrio Salmonicida ◽  
First Time

ABSTRACT The presence of the tetracycline resistance determinant tet(M) in human clinical isolates of Escherichia coli is described for the first time in this report. The homologue was >99% identical to the tet(M) genes reported to occur in Lactobacillus plantarum, Neisseria meningitidis, and Streptococcus agalactiae, and 3% of the residues in its deduced amino acid sequence diverge from tet(M) of Staphylococcus aureus. Sequence analysis of the regions immediately flanking the gene revealed that sequences upstream of tet(M) in E. coli have homology to Tn916; however, a complete IS26 insertion element was present immediately upstream of the promoter element. Downstream from the termination codon is an insertion sequence that was homologous to the ISVs1 element reported to occur in a plasmid from Vibrio salmonicida that has been associated with another tetracycline resistance determinant, tet(E). Results of mating experiments demonstrated that the E. coli tet(M) gene was on a mobile element so that resistance to tetracycline and minocycline could be transferred to a susceptible strain by conjugation. Expression of the cloned tet(M) gene, under the control of its own promoter, provided tetracycline and minocycline resistance to the E. coli host.

scholarly journals Characterization of Shiga Toxin-Producing Escherichia coli O26 Strains and Establishment of Selective Isolation Media for These Strains

2002 ◽  
Vol 40 (3) ◽  
pp. 922-925 ◽  
Author(s):  
R. Hiramatsu ◽  
M. Matsumoto ◽  
Y. Miwa ◽  
Y. Suzuki ◽  
M. Saito ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Selective Isolation ◽  
Isolation Media

scholarly journals Detection of Carbapenem-Resistant Genes in Escherichia coli Isolated from Drinking Water in Khartoum, Sudan

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Neama Esmat Mahmoud ◽  
Hisham N. Altayb ◽  
Reem Majzoub Gurashi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Treatment Options ◽  
Tetracycline Resistance ◽  
Carbapenem Resistance ◽  
High Rate ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
First Time

Waterborne Escherichia coli are a major reservoir of antimicrobial resistance (AMR). Carbapenem-resistance, especially when mediated by transferable carbapenemase-encoding genes, is spreading worldwide and causing dramatically limiting treatment options. In our country, studies for the detection of carbapenem resistance in drinking water do not exist; therefore, this work was carried out to determine the prevalence of carbapenem-resistant genes “blaKPC, blaIMP, blaNDM, blaSPM, blaVIM, and blaOXA-48” among Escherichia coli isolated from drinking water in Khartoum, Sudan. A total of forty-five E. coli bacteria were isolated from different sources of drinking water. Antimicrobial susceptibility testing was performed using imipenem (10 mg/disc), gentamicin (10 mg/disc), ceftriaxone (30 mg/disc), ciprofloxacin (5 mg/disc), chloramphenicol (30 mg/disc), and tetracycline (30 mg/disc). “Sensitive” or “resistant” patterns of E. coli were judged using antibiotic minimum inhibitory concentration (MIC). Bacterial genomic DNA was extracted by the boiling method, and then multiplex polymerase chain reaction was performed to detect the carbapenemase genes (blaKPC, blaIMP, blaNDM, blaSPM, blaVIM, and blaOXA-48). Multiplex PCR assays confirmed the presence of carbapenemase genes in 28% of all water isolates. OXA-48 gene was the most predominant gene, detected in 15.5% of the isolates. The blaKPC and blaSPM genes were also detected in 4.4% and 8.8% of the isolates, respectively. However, the isolates were negative for blaNDM, blaVIM, and blaIMP genes. The isolates showed a high rate of tetracycline resistance (97.7%), followed by gentamicin (57.7%), ciprofloxacin (46.6%), ceftriaxone (35.5%), and chloramphenicol (31.1%). In conclusion, this study confirmed for the first time the presence of E. coli carried carbapenem-resistant genes in the drinking water of Khartoum state, Sudan. These isolates commonly carried OXA-48 (7/45), followed by SPM (4/45) and KPC (2/45).

Antibacterial Activities of Sirih Merah (Piper crocatum) Leaf Extracts

2019 ◽  
Vol 5 (3) ◽  
pp. 1-10
Author(s):  
Puspa Julistia Puspita ◽  
Mega Safithri ◽  
Nirmala Peni Sugiharti
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Agent ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Leaf Extracts ◽  
Herbal Plants

Piper crocatum is one of medicinal herbal plants with a large number of benefits. Usually herbal plants have activity as antibacterial agent. Therefore, the objectives of this research were to obtain information on antibacterial activities of the leaf extracts of Piper crocatum againts four types of bacteria, in that Staphylococcus, Bacillus substilis, Escherichia coli, and Pseudomonas aeruginosa and then to analyze the phytochemistry of the leaf extracts of Piper crocatum. The leaves of Piper crocatum were extracted by maceration and reflux using ethanol 30%. The assays of the antibacterial activities and phytochemistry on the extracts were carried out using the method of Maria Bintang. Results showed that the yield of the extraction using ethanol by maceration method was 20.8%. Meanwhile, using the reflux method, the yield was obtained about 26.25%. The phytochemistry analysis showed that the leaf extracts of Piper crocatum contained alkaloid, steroid and tanin. According to this study, it was found that the leaf extract of Piper crocatum can be used to inhibit the growth of B. subtilis and P. aeuruginosa, but can not inhibit the growth of E.coli and S. aureus.

Iso-octenidine: Promising Octenidine Analogue with Improved Solubility

2020 ◽  
Vol 17 ◽  
Author(s):  
Igor K. Yakuschenko ◽  
Nataliya N. Pozdeeva ◽  
Viktoriya A. Mumyatova ◽  
Alexey A. Terentiev ◽  
Svyatoslav Ya. Gadomsky
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Micrococcus Luteus ◽  
Octenidine Dihydrochloride ◽  
First Time

: Iso-octenidine, an isomer of octenidine dihydrochloride, was synthesized and studied for the first time. Isooctenidine was demonstrated to be 3-fold more soluble in water in comparison to original octenidine, and both substances had remarkably similar antibacterial activity (tested on Escherichia Coli and Micrococcus luteus).

scholarly journals Structure of the master regulator Rns reveals an inhibitor of enterotoxigenic Escherichia coli virulence regulons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles R. Midgett ◽  
Kacey Marie Talbot ◽  
Jessica L. Day ◽  
George P. Munson ◽  
F. Jon Kull
Keyword(s):  
Escherichia Coli ◽  
Small Molecules ◽  
Family Member ◽  
Shigella Flexneri ◽  
Decanoic Acid ◽  
Enterotoxigenic Escherichia Coli ◽  
Gram Negative Bacteria ◽  
Enteric Infections ◽  
First Time ◽  
Arac Family

AbstractEnteric infections caused by the gram-negative bacteria enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, Shigella flexneri, and Salmonella enterica are among the most common and affect billions of people each year. These bacteria control expression of virulence factors using a network of transcriptional regulators, some of which are modulated by small molecules as has been shown for ToxT, an AraC family member from V. cholerae. In ETEC the expression of many types of adhesive pili is dependent upon the AraC family member Rns. We present here the 3 Å crystal structure of Rns and show it closely resembles ToxT. Rns crystallized as a dimer via an interface similar to that observed in other dimeric AraC’s. Furthermore, the structure of Rns revealed the presence of a ligand, decanoic acid, that inhibits its activity in a manner similar to the fatty acid mediated inhibition observed for ToxT and the S. enterica homologue HilD. Together, these results support our hypothesis that fatty acids regulate virulence controlling AraC family members in a common manner across a number of enteric pathogens. Furthermore, for the first time this work identifies a small molecule capable of inhibiting the ETEC Rns regulon, providing a basis for development of therapeutics against this deadly human pathogen.

Large-scale production of citrate synthase from a cloned gene

1982 ◽  
Vol 60 (12) ◽  
pp. 1143-1147 ◽  
Author(s):  
Harry W. Duckworth ◽  
Alexander W. Bell
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Citrate Synthase ◽  
Specific Activity ◽  
Tetracycline Resistance ◽  
Scale Production ◽  
Ampicillin Resistance ◽  
Colicin E1 ◽  
Large Scale Production ◽  
Cloned Gene

Starting with a colicin E1 resistance recombinant plasmid which contains gltA, the gene for citrate synthase in Escherichia coli, we have constructed an ampicillin-resistance plasmid containing the gltA region as a 2.9-kilobase-pair insert in the tetracycline-resistance region of pBR322. Escherichia coli HB101 harbouring this plasmid, when grown on rich medium containing ampicillin, contains citrate synthase as about 8% of its soluble protein. The enzyme has been purified from this rich source and is identical to the chromosomal enzyme prepared previously in every property tested, except for specific activity, which is 64 U∙mg−1 as compared with 45–50 U∙mg−1 previously obtained. The N-terminal sequences of both enzymes are reported, and they are identical up to residue 16 at least. The overall yield of pure enzyme, starting with the cells grown in 15 L of medium, is 600–800 mg.

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