scholarly journals Lytic and Lysogenic Infection of DiverseEscherichia coli and Shigella Strains with a Verocytotoxigenic Bacteriophage

2001 ◽  
Vol 67 (9) ◽  
pp. 4335-4337 ◽  
Author(s):  
Chloe E. James ◽  
Karen N. Stanley ◽  
Heather E. Allison ◽  
Harry J. Flint ◽  
Colin S. Stewart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Plaque Assay ◽  
Kanamycin Resistance ◽  
Lytic Infection ◽  
Lytic Cycle ◽  
Animal Origin ◽  
Kanamycin Resistance Gene ◽  
E Coli ◽  
Infected Cells

ABSTRACT A verocytotoxigenic bacteriophage isolated from a strain of enterohemorrhagic Escherichia coli O157, into which a kanamycin resistance gene (aph3) had been inserted to inactivate the verocytotoxin gene (vt2 ), was used to infect Enterobacteriaceae strains. A number ofShigella and E. coli strains were susceptible to lysogenic infection, and a smooth E. coli isolate (O107) was also susceptible to lytic infection. The lysogenized strains included different smooth E. coli serotypes of both human and animal origin, indicating that this bacteriophage has a substantial capacity to disseminate verocytotoxin genes. A novel indirect plaque assay utilizing an E. coli recA441 mutant in which phage-infected cells can enter only the lytic cycle, enabling detection of all infective phage, was developed.

scholarly journals Construction and Complementation of In-Frame Deletions of the Essential Escherichia coli Thymidylate Kinase Gene

2006 ◽  
Vol 72 (2) ◽  
pp. 1288-1294 ◽  
Author(s):  
David-Nicolas Chaperon
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Homo Sapiens ◽  
Bacteriophage T4 ◽  
Kanamycin Resistance ◽  
Kanamycin Resistance Gene ◽  
Kinase Gene ◽  
Thymidylate Kinase ◽  
E Coli ◽  
Putative Operon

ABSTRACT This work reports the construction of Escherichia coli in-frame deletion strains of tmk, which encodes thymidylate kinase, Tmk. The tmk gene is located at the third position of a putative five-gene operon at 24.9 min on the E. coli chromosome, which comprises the genes pabC, yceG, tmk, holB, and ycfH. To avoid potential polar effects on downstream genes of the operon, as well as recombination with plasmid-encoded tmk, the tmk gene was replaced by the kanamycin resistance gene kka1, encoding amino glycoside 3′-phosphotransferase kanamycin kinase. The kanamycin resistance gene is expressed under the control of the natural promoter(s) of the putative operon. The E. coli tmk gene is essential under any conditions tested. To show functional complementation in bacteria, the E. coli tmk gene was replaced by thymidylate kinases of bacteriophage T4 gp1, E. coli tmk, Saccharomyces cerevisiae cdc8, or the Homo sapiens homologue, dTYMK. Growth of these transgenic E. coli strains is completely dependent on thymidylate kinase activities of various origin expressed from plasmids. The substitution constructs show no polar effects on the downstream genes holB and ycfH with respect to cell viability. The presented transgenic bacteria could be of interest for testing of thymidylate kinase-specific phosphorylation of nucleoside analogues that are used in therapies against cancer and infectious diseases.

Formaldehyde effects on kanamycin resistance gene of inactivated recombinant Escherichia coli vaccines

2020 ◽  
Vol 42 (11) ◽  
pp. 2223-2230
Author(s):  
Rafael A. Donassolo ◽  
Marcos Roberto A. Ferreira ◽  
Clóvis Moreira Jr ◽  
Lucas M. dos Santos ◽  
Emili Griep ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Kanamycin Resistance ◽  
Recombinant Escherichia Coli ◽  
Kanamycin Resistance Gene

The influence of antibiotic resistance gene carriage on biofilm formation by two Escherichia coli strains associated with urinary tract infections

2014 ◽  
Vol 60 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Amy Huei Teen Teh ◽  
Yi Wang ◽  
Gary A. Dykes
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Urinary Tract ◽  
Resistance Gene ◽  
Biofilm Formation ◽  
Antibiotic Resistance Gene ◽  
Kanamycin Resistance ◽  
Marker Genes ◽  
E Coli ◽  
Tract Infections

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli are one of the most common forms of human disease. In this study, the effect of the presence of newly acquired antibiotic resistance genes on biofilm formation of UTI-associated E. coli strains was examined. Two clinical UTI-associated E. coli strains (SMC18 and SMC20) carrying different combinations of virulence genes were transformed with pGEM-T, pGEM-T::KmΔAmp, or pGEM-T::Km to construct ampicillin-resistant (KmSAmpR), kanamycin-resistant (KmRAmpS), or ampicillin- and kanamycin-resistant (KmRAmpR) strains. Transformed and wild-type strains were characterized for biofilm formation, bacterial surface hydrophobicity, auto-aggregation, morphology, and attachment to abiotic surfaces. Transformation with a plasmid carrying an ampicillin resistance gene alone decreased (p < 0.05) biofilm formation by SMC18 (8 virulence marker genes) but increased (p < 0.05) biofilm formation by SMC20 (5 virulence marker genes). On the other hand, transformation with a plasmid carrying a kanamycin resistance gene alone or both ampicillin and kanamycin resistance genes resulted in a decrease (p < 0.05) in biofilm formation by SMC18 but did not affect (p > 0.05) the biofilm formation by SMC20. Our results suggest that transformation of UTI-associated E. coli with plasmids carrying different antibiotic resistance gene(s) had a significant impact on biofilm formation and that these effects were both strain dependent and varied between different antibiotics.

scholarly journals The Arcanobacterium(Actinomyces) pyogenes Plasmid pAP1 Is a Member of the pIJ101/pJV1 Family of Rolling Circle Replication Plasmids

1998 ◽  
Vol 180 (12) ◽  
pp. 3233-3236 ◽  
Author(s):  
Stephen J. Billington ◽  
B. Helen Jost ◽  
J. Glenn Songer
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Sequence Similarity ◽  
Kanamycin Resistance ◽  
Corynebacterium Pseudotuberculosis ◽  
Rolling Circle Replication ◽  
Kanamycin Resistance Gene ◽  
Rolling Circle ◽  
Rolling Circle Mechanism ◽  
Actinomyces Pyogenes

ABSTRACT The 2.4-kb plasmid pAP1 from Arcanobacterium(Actinomyces) pyogenes had sequence similarity within the putative replication protein and double-stranded origin with the pIJ101/pJV1 family of plasmids. pJGS84, a derivative of pAP1 containing a kanamycin resistance gene, was able to replicate inEscherichia coli and Corynebacterium pseudotuberculosis, as well as in A. pyogenes. Detection of single-stranded DNA intermediates of pJGS84 replication suggested that this plasmid replicates by the rolling circle mechanism.

scholarly journals Molecular survey of mcr1 and mcr2 plasmid mediated colistin resistance genes in Escherichia coli isolates of animal origin in Iran

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kayhan Ilbeigi ◽  
Mahdi Askari Badouei ◽  
Hossein Vaezi ◽  
Hassan Zaheri ◽  
Sina Aghasharif ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Companion Animals ◽  
Multidrug Resistant ◽  
Animal Origin ◽  
Colistin Resistance ◽  
E Coli ◽  
High Level ◽  
Farming Industry

Abstract Objectives The emergence of colistin-resistant Enterobacteriaceae from human and animal sources is one of the major public health concerns as colistin is the last-resort antibiotic for treating infections caused by multidrug-resistant Gram-negative bacteria. We aimed to determine the prevalence of the prototype widespread colistin resistance genes (mcr-1 and mcr-2) among commensal and pathogenic Escherichia coli strains isolated from food-producing and companion animals in Iran. Results A total of 607 E. coli isolates which were previously collected from different animal sources between 2008 and 2016 used to uncover the possible presence of plasmid-mediated colistin resistance genes (mcr-1 and mcr-2) by PCR. Overall, our results could not confirm the presence of any mcr-1 or mcr-2 positive E. coli among the studied isolates. It is concluded that despite the important role of food-producing animals in transferring the antibiotic resistance, they were not the main source for carriage of mcr-1 and mcr-2 in Iran until 2016. This study suggests that the other mcr variants (mcr-3 to mcr-9) might be responsible for conferring colistin resistance in animal isolates in Iran. The possible linkage between pig farming industry and high level of mcr carriage in some countries needs to be clarified in future prospective studies.

scholarly journals Reduced Virulence of a Bordetella bronchiseptica Siderophore Mutant in Neonatal Swine

2001 ◽  
Vol 69 (4) ◽  
pp. 2137-2143 ◽  
Author(s):  
Karen B. Register ◽  
Thomas F. Ducey ◽  
Susan L. Brockmeier ◽  
David W. Dyer
Keyword(s):  
Nasal Cavity ◽  
Resistance Gene ◽  
Parent Strain ◽  
Virulent Strain ◽  
Clinical Signs ◽  
Kanamycin Resistance ◽  
Live Vaccine ◽  
Bordetella Bronchiseptica ◽  
Kanamycin Resistance Gene ◽  
Phosphate Buffered Saline

ABSTRACT One means by which Bordetella bronchiseptica scavenges iron is through production of the siderophore alcaligin. A nonrevertible alcaligin mutant derived from the virulent strain 4609, designated DBB25, was constructed by insertion of a kanamycin resistance gene into alcA, one of the genes essential for alcaligin biosynthesis. The virulence of the alcA mutant in colostrum-deprived, caesarean-delivered piglets was compared with that of the parent strain in two experiments. At 1 week of age, piglets were inoculated with phosphate-buffered saline, 4609, or DBB25. Two piglets in each group were euthanatized on day 10 postinfection. The remainder were euthanatized at 21 days postinfection. Clinical signs, including fever, coughing, and sneezing, were present in both groups. Nasal washes performed 7, 14, and 21 days postinoculation demonstrated that strain DBB25 colonized the nasal cavity but did so at levels that were significantly less than those achieved by strain 4609. Analysis of colonization based on the number of CFU per gram of tissue recovered from the turbinate, trachea, and lung also demonstrated significant differences between DBB25 and 4609, at both day 10 and day 21 postinfection. Mild to moderate turbinate atrophy was apparent in pigs inoculated with strain 4609, while turbinates of those infected with strain DBB25 developed no or mild atrophy. We conclude from these results that siderophore production by B. bronchiseptica is not essential for colonization of swine but is required for maximal virulence. B. bronchiseptica mutants with nonrevertible defects in genes required for alcaligin synthesis may be candidates for evaluation as attenuated, live vaccine strains in conventionally reared pigs.

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