Restriction map of corynebacteriophages beta c and beta vir and physical localization of the diphtheria tox operon

Costa, Jonathan L.; Michel, J L; Rappuoli, Rino; Murphy, John R.

doi:10.1128/jb.148.1.124-130.1981

Cited by 36 publications

(16 citation statements)

References 29 publications

(27 reference statements)

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“…Most of these were innocuous and included Corynebacterium, Microbacterium, Propionibacterium, Acinetobacter, Stenotrophomonas, Methylobacterium and Micrococcus (Akter, Park, & Yin, 2016;Bergogne-Be′re′zin, 1994;Collins, Hoyles, Foster, & Falsen, 2004). A small number of species in these genera are human pathogens, such as certain Corynebacterium species that can cause acute disease, most notably diphtheria (Costa, Michel, Rappuoli, & Murphy, 1981). Additionally, some Acinetobacter species frequently cause bacteraemia, urinary tract infections, meningitis, infective endocarditis and infections of wounds and burns (Siegman-Igra, Bar-Yosef, Gorea, & Avram, 1993;Hu et al, 2011).…”

Section: Profile Of Bacteria Distribution In Each Samplementioning

confidence: 99%

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Cheng

2017

J Applied Entomology

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The tick Haemaphysalis flava is one of the most significant blood-feeding arthropod parasites and is a vector for numerous human and animal pathogens. However, a comprehensive investigation of the microbial communities found in the saliva of this tick species is lacking. This study used 16S rRNA Illumina sequencing to characterize the compositions of microbiomes present in saliva and whole tick samples isolated from engorged and partially fed adult H. flava females. This revealed that the bacterial diversity present in tick saliva increased after a prolonged blood meal, and that the species diversity found in saliva was significantly higher than that of whole ticks. Three bacteria phyla, in particular, made up more than 80% of the microbial community across all samples-Proteobacteria, Firmicutes and Actinobacteria. Furthermore, some of the genera identified in this study had not previously been reported in ticks before, such as Facklamia, Vagococcus, Ruminococcus, Lachnospira, Bradyrhizobium, Peptostreptococcus, Jeotgalicoccus, Roseburia, Brachybacterium, Sporosarcina, u114, Megamonas and Dechloromonas. Finally, we found that many of the isolated bacteria were opportunistic pathogens, indicating a potential risk to humans and livestock exposed to H. flava.These results will contribute to fully understanding the transmission of tick-borne pathogens. K E Y W O R D Sbacteria, Haemaphysalis flava, microbiome, saliva | INTRODUCTIONHaemaphysalis flava (Acari: Ixodidae) is a prevalent hard tick species found in many countries that feeds on a wide variety of hosts, including hares, dogs, cows, horses, wild boar, deer, bears, pigs, cattle, sheep, goats, hedgehogs, pandas, cats, squirrels and golden pheasants (He, Tang, & Cheng, 2016). As a vector for numerous pathogens, including encephalitis virus (Ko et al., 2010), Borrelia burgdorferi (Moon et al., 2013), Rickettsia (Someya, Ito, Maeda, & Ikenaga, 2015), Francisella tularensis (Kim et al., 2005), Bartonella (Ozawa et al., 1982), Anaplasma and Ehrlichia (Rar et al., 2010), H. flava has emerged as a significant threat to public health.Tick saliva plays a pivotal role in pathogen transmission (Nuttall & Labuda, 2004) and studying the microbes that inhabit it can contribute to both conventional disease discovery (in which a pathogen is discovered in a host and then identified in the tick population) and reverse discovery (in which a potential pathogen is characterized in ticks and then is subsequently shown to cause disease) (Tijsse-Klasen, Koopmans, & Sprong, 2014). However, information on the microbial populations present in tick saliva remains scarce. To date, the saliva microbiomes of Amblyomma maculatum (Budachetri et al., 2014) and Rhipicephalus microplus (Xiang, Poźniak, & Cheng, 2017) are the only two that have been surveyed. The microflora of saliva isolated from H. flava has been partially analysed using PCR-denaturing gradient gel electrophoresis (PCR-DGGE), but this system is unable to reveal in detail the microbial communities of saliva (He et al...

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Section: Profile Of Bacteria Distribution In Each Samplementioning

confidence: 99%

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Cheng

2017

J Applied Entomology

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“…However, the methods for establishing this relationship were far too cumbersome to encourage an assessment of tox gene carriage by other Toxisolates. Recently we and others (3,5) reported the isolation of a DNA restriction fragment of beta-converting phage which contains the gene for diphtheria toxin. The presence of the tox gene within this fragment has been confirmed by nucleotide sequencing, and segments of the fragment that can be used as probes for the tox gene have been identified.…”

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confidence: 99%

Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae

Groman¹,

Cianciotto²,

Bjorn³

et al. 1983

Infect Immun

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Three probes have been described which can be used to detect the presence of DNA sequences homologous to the tox gene of Corynebacterium diphtheriae. Probes "A" and "B" detected sequences coding for A and B fragments of diphtheria toxin, respectively. The third "A-B" probe contained both the A and B coding sequences. The B probe was completely unambiguous in detecting only toxin-related sequences, and the A probe was only slightly less so. The efficacy of the probes was tested on a series of toxinogenic and nontoxinogenic isolates of C. diphtheriae. All isolates which were toxinogenic as characterized by the gel immunodiffusion technique gave positive reactions with the probes. Of particular interest was the finding that 14 of 43 nontoxinogenic isolates also carried DNA homologous to both the A and B probes. All 14 isolates were nontoxinogenic by the rabbit intracutaneous test as well as by the gel immunodiffusion test; however, 12 of them produced ADP-ribosylating activity, whereas two were negative. The isolates producing ADP-ribosylating activity belonged to a cohort of cultures, of which 11 were isolated in South Dakota and 1 was isolated in Montana. Genomic DNAs of all 12 appeared to be identical when restriction enzyme digest patterns were compared, and the same fragment carried the tox gene in all of them. The tox-bearing nontoxinogenic isolates from Alaska and Florida each had unique restriction patterns and did not produce ADP-ribosylating activity. A number of genomic fragments of all the tox-bearing nontoxinogenic isolates hybridized with beta converting phage DNA. The significance of these observations to the natural history of diphtheria was discussed.

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“…Diphtheria toxin is the product of a gene (tox) present in the genome of lysogenic corynephages which infect the gram-positive bacterium Corynebacterium diphtheriae: after lysogenisation the tox gene is expressed under bacterial control (3). Corynephages possess a single linear ds-DNA molecule, ranging in size from 35 to 38 Kb according to the strain (4)(5)(6). As with lambda phage, corynephage DNA can circularize through cos sites and integrate into two specific sites of the C. diphtheriae genome, attBl and attB, (7) by recombination with a corresponding phage site, attP.…”

Section: Introductionmentioning

confidence: 99%

“…Restriction maps for several phage strains have been determined and the cos site C I R L Press Limited, Oxford, England. and att site as well as the tox gene have also been physically mapped (4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

The complete nucleotide sequence of the gene coding for diphtheria toxin in the corynephage omega (tox⁺) genome

Ratti¹,

Rappuoli²,

Giannini³

1983

Nucl Acids Res

109

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A segment of corynephage omega (tox+) DNA, containing the gene for diphtheria toxin (tox) was fragmented with restriction enzymes and the fragments cloned into M13 vectors for nucleotide sequence determination. A long open reading frame was shown to encode the tox gene by comparing the predicted amino acid sequence with that of peptides derived from the mature toxin molecule. Analysis of the nucleotide sequence shows RNA polymerase and ribosome binding signals preceding a GTG codon in the open reading frame: if this is the correct starting signal for translation, then a 25 amino acid signal peptide can be predicted for the toxin molecule.

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Restriction map of corynebacteriophages beta c and beta vir and physical localization of the diphtheria tox operon

Abstract: The BamHI, EcoRI, HindIII, and KpnI restriction endonuclease maps of corynebacteriophage ,Bc and 8B.ir were constructed. Bvir appeared to be identical to ,BC, except for an approximate 1-kilobase deletion that removed a BamHI site,

Cited by 36 publications

References 29 publications

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae

The complete nucleotide sequence of the gene coding for diphtheria toxin in the corynephage omega (tox⁺) genome

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Restriction map of corynebacteriophages beta c and beta vir and physical localization of the diphtheria tox operon

Abstract: The BamHI, EcoRI, HindIII, and KpnI restriction endonuclease maps of corynebacteriophage ,Bc and 8B.ir were constructed. Bvir appeared to be identical to ,BC, except for an approximate 1-kilobase deletion that removed a BamHI site,

Cited by 36 publications

References 29 publications

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Tick saliva microbiomes isolated from engorged and partially fed adults of Haemaphysalis flava tick females

Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae

The complete nucleotide sequence of the gene coding for diphtheria toxin in the corynephage omega (tox+) genome

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The complete nucleotide sequence of the gene coding for diphtheria toxin in the corynephage omega (tox⁺) genome