Construction and characterization of E. coli promoter-probe plasmid vectors III. pBR322 derivatives with deletions in the tetracycline resistance promoter region

Abstract The objective of this study was to evaluate the longitudinal effect of enrofloxacin or tulathromycin use in calves at high risk of bovine respiratory disease (BRD) on antimicrobial resistance genes and mutation in quinolone resistance-determining regions (QRDR) in fecal E. coli. Calves at high risk of developing BRD were randomly enrolled in one of three groups receiving: (1) enrofloxacin (ENR; n = 22); (2) tulathromycin (TUL; n = 24); or (3) no treatment (CTL; n = 21). Fecal samples were collected at enrollment and at 7, 28, and 56 days after beginning treatment, cultured for Escherichiacoli (EC) and DNA extracted. Isolates were screened for cephalosporin, quinolone and tetracycline resistance genes using PCR. QRDR screening was conducted using Sanger sequencing. The only resistance genes detected were aac(6′)Ib-cr (n = 13), bla-CTX-M (n = 51), bla-TEM (n = 117), tetA (n = 142) and tetB (n = 101). A significantly higher detection of gyrA mutated at position 248 at time points 7 (OR = 11.5; P value = 0.03) and 28 (OR = 9.0; P value = 0.05) was observed in the ENR group when compared to calves in the control group. Our findings support a better understanding of the potential impacts from the use of enrofloxacin in calves on the selection and persistence of resistance.

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Isolation and characterization of promoters from the Lactobacillus casei temperate bacteriophage A2

Canadian Journal of Microbiology ◽

10.1139/m97-151 ◽

1997 ◽

Vol 43 (11) ◽

pp. 1063-1068 ◽

Cited By ~ 4

Author(s):

Pilar García ◽

Juan Evaristo Suárez ◽

Victoria Bascarán ◽

Ana Rodríguez

Keyword(s):

Lactobacillus Casei ◽

Initiation Site ◽

Dna Fragments ◽

Chloramphenicol Resistance ◽

Consensus Sequences ◽

E Coli ◽

Isolation And Characterization ◽

Promoter Probe ◽

Extension Analysis

Random Sau3AI DNA fragments from the temperate Lactobacillus bacteriophage A2 were cloned into the promoter-probe plasmid pGKV210. Seven DNA fragments with promoter activity were selected, after transformation of Escherichia coli and Lactococcus lactis, subsp. lactis, through the chloramphenicol resistance they conferred to the corresponding clones. The seven promoters were functional in Lactobacillus casei. Their strength was analysed by measuring the levels of chloramphenicol resistance and chloramphenicol acetyltransferase activity induced in each host. The nucleotide sequences of these fragments were determined and primer extension analysis was used to locate the initiation site of transcription from each promoter in E. coli. The promoters contained −10 and −35 regions similar to the consensus sequences of E. coli and Lactobacillus promoters.Key words: bacteriophage, Lactobacillus, promoter.

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Characterization of Cefoxitin-Resistant Escherichia coli Isolates from Recreational Beaches and Private Drinking Water in Canada between 2004 and 2006

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01353-08 ◽

2009 ◽

Vol 53 (7) ◽

pp. 3126-3130 ◽

Cited By ~ 27

Author(s):

L. F. Mataseje ◽

N. Neumann ◽

B. Crago ◽

P. Baudry ◽

G. G. Zhanel ◽

...

Keyword(s):

Escherichia Coli ◽

Drinking Water ◽

Multidrug Resistance ◽

Promoter Region ◽

Water Sources ◽

Wild Type ◽

Phylogenetic Groups ◽

E Coli ◽

Recreational Beaches

ABSTRACT A total of 142 cefoxitin-resistant Escherichia coli isolates from water sources were collected across Canada. Multidrug resistance was observed in 65/142 (45.8%) isolates. The bla CMY-2 gene was identified in 110/142 (77.5%) isolates. Sequencing of the chromosomal ampC promoter region showed mutations from the wild type, previously shown to hyperproduce AmpC. CMY-2-producing plasmids predominantly belonged to replicon groups I1-Iγ, A/C, and K/B. The majority of the E. coli isolates belonged to the nonvirulent phylogenetic groups A and B1.

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Predicting whether or not a nucleic acid sequence is an E. coli promoter region using genetic programming

Proceedings First International Symposium on Intelligence in Neural and Biological Systems. INBS'95 ◽

10.1109/inbs.1995.404270 ◽

2002 ◽

Cited By ~ 5

Author(s):

S. Handley

Keyword(s):

Nucleic Acid ◽

Genetic Programming ◽

Promoter Region ◽

Nucleic Acid Sequence ◽

E Coli ◽

Coli Promoter

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Cloning and Characterization of a Tetracycline Resistance Determinant Present in Agrobacterium tumefaciens C58

Journal of Bacteriology ◽

10.1128/jb.181.2.618-626.1999 ◽

1999 ◽

Vol 181 (2) ◽

pp. 618-626 ◽

Cited By ~ 33

Author(s):

Zhao-Qing Luo ◽

Stephen K. Farrand

Keyword(s):

Agrobacterium Tumefaciens ◽

Promoter Region ◽

Tetracycline Resistance ◽

Homologous Region ◽

Polycyclic Compounds ◽

Repressor Proteins ◽

Repressive Effect ◽

Agrobacterium Tumefaciens C58 ◽

Spontaneous Mutants

ABSTRACT Agrobacterium tumefaciens C58 and its derivatives give rise to spontaneous mutants resistant to tetracycline at a high frequency. We observed that a mutation affecting a tRNA processing function significantly affected the emergence of such mutants, suggesting that C58 contained a positively acting gene conferring resistance to tetracycline. A cosmid clone conferring resistance to tetracycline in Escherichia coli andAgrobacterium was isolated from a genomic bank of one such mutant. Subcloning, transposon mutagenesis, and DNA sequence analysis revealed that this DNA fragment contained two divergently transcribed genes, tetA and tetR, encoding products that were very similar to proteins of the Tet(A) class of tetracycline resistance systems. In the clone from this mutant, tetR was disrupted by an IS426. The homologous region from wild-type NT1 contained an intact tetR gene and did not confer resistance to tetracycline. Hybridization analysis showed that of 22 members of the genus Agrobacterium surveyed, only strains C58 and T37 contained the tet determinant. Moreover, only these two strains mutated to resistance to this antibiotic. Unlike other Tet(A) systems, neither tetracycline nor a series of its derivatives induced the expression of this tet gene unit. Other polycyclic compounds, including many of plant origin, also did not induce this tet gene system. The divergent promoter region of this tet system contained a single inverted repeat element identical to one such operator repeat in the promoter region of the tet determinant from the IncP1α R plasmid RP4. TetR repressor proteins from the Agrobacterium tetsystem and from RP4 interacted with the heterologous operators. While the repressive effect of the TetR protein from strain C58 (TetRC58) on the tetA gene from strain RP4 (tetA RP4) was not relieved by tetracycline, repression of tetA C58 by TetRRP4was lifted by this antibiotic.

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Identification and Characterization of Sporulation-Dependent Promoters Upstream of the Enterotoxin Gene (cpe) of Clostridium perfringens

Journal of Bacteriology ◽

10.1128/jb.180.1.136-142.1998 ◽

1998 ◽

Vol 180 (1) ◽

pp. 136-142 ◽

Cited By ~ 103

Author(s):

Yuling Zhao ◽

Stephen B. Melville

Keyword(s):

Clostridium Perfringens ◽

Dna Sequences ◽

Promoter Region ◽

Food Poisoning ◽

In Vitro Transcription ◽

Shuttle Vectors ◽

E Coli ◽

Dna Template

ABSTRACT Three promoter sites (P1, P2, and P3) responsible for the sporulation-associated synthesis of Clostridium perfringensenterotoxin, a common cause of food poisoning in humans and animals, were identified. Nested and internal deletions of the cpepromoter region were made to narrow down the location of promoter elements. To measure the effects of the deletions on the expression ofcpe, translational fusions containing the promoter deletions were made with the gusA gene of Escherichia coli, which codes for β-glucuronidase; E. coli-C. perfringens shuttle vectors carrying the fusions were introduced into C. perfringens by electroporation. In addition, in vitro transcription assays were performed with the cpepromoter region as the DNA template for extracts made from sporulating cells. DNA sequences upstream of P1 were similar to consensus SigK-dependent promoters, while P2 and P3 were similar to consensus SigE-dependent promoters. SigE and SigK are sporulation-associated sigma factors known to be active in the mother cell compartment of sporulating cells of Bacillus subtilis, the same compartment in which enterotoxin is synthesized in C. perfringens.

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Characterization of tetracycline resistance genes in Escherichia coli isolated from feedlot cattle administered therapeutic or subtherapeutic levels of tetracycline

Canadian Journal of Microbiology ◽

10.1139/cjm-2012-0660 ◽

2013 ◽

Vol 59 (4) ◽

pp. 287-290 ◽

Cited By ~ 3

Author(s):

T.W. Alexander ◽

X. Jin ◽

Q. Li ◽

S. Cook ◽

T.A. McAllister

Keyword(s):

Escherichia Coli ◽

Resistance Genes ◽

Tetracycline Resistance ◽

Feedlot Cattle ◽

E Coli ◽

Treatment Regimes ◽

Tetracycline Resistance Genes ◽

Polymerase Chain ◽

Selection Of

The effect of administering feedlot cattle subtherapeutic levels of chlortetracycline (CT) or CT and therapeutic levels of oxytetracycline (CT-OX) on resistance genotypes in Escherichia coli was investigated. Detection of genes tet(A), tet(B), and tet(C) encoded by tetracycline-resistant isolates (CT, N = 77; CT-OX, N = 99) was performed by multiplex polymerase chain reaction (PCR). Prevalence of tet(A) was similar in isolates across treatment regimes; however, prevalence of tet(B) was lower (18% versus 34%; P < 0.05) and tet(C) was higher (46% versus 28%; P < 0.05) in CT isolates compared with CT-OX isolates. To further characterize selection of resistance genotypes in E. coli, a group of intermediately tetracycline-resistant E. coli (N = 48) was analyzed. The tet(C) gene was present in 92% of these isolates. Copies of tet(C) transcripts, analyzed by real-time PCR, indicated that upregulation did not occur in tetracycline-resistant isolates when compared with intermediately resistant isolates. The minimum inhibitory concentrations of tetracycline, chlortetracycline, and oxytetracycline were also tested on isolates with different resistance genes. The minimum inhibitory concentration was dependent on the tetracycline analogue and the nature of encoded resistance. These data indicate that tetracycline analogues should not be used interchangeably to evaluate resistance and that prevalence of resistance genes in E. coli can vary according to the tetracycline analogue administered to cattle.

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