Properties of psychrophilic bacteriophage specific for Micrococcus cryophilus

1971 ◽  
Vol 17 (2) ◽  
pp. 157-160 ◽  
Author(s):  
Charles F. Kulpa Jr. ◽  
R. H. Olsen

A bacteriophage infective for the obligate psychrophile, Micrococcus cryophilus, was isolated from sewage. The host range is limited to this species. Phage and host DNA are similar in G–C content. The bacteriophage has an average burst size of 290 at 20 °C and 50 at 3.5 °C. The phage is thermosensitive, being 99.9% inactivated in 5 min at 45 °C. This is the first report of the isolation of bacteriophage infective for gram-positive psychrophiles.

2021 ◽  
pp. 100073
Author(s):  
Julie Lourtet-Hascoet ◽  
Sébastien Hascoet ◽  
Jean-Louis Galinier ◽  
Benoît Fontenel ◽  
Benoît Monteil ◽  
...  

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1086-1093 ◽  
Author(s):  
Marie-Laure Desprez-Loustau ◽  
Marie Massot ◽  
Nicolas Feau ◽  
Tania Fort ◽  
Antonio de Vicente ◽  
...  

Mango leaves and inflorescences infected by powdery mildew in southern Spain were analyzed using multigene sequencing (ITS + 4 single-copy coding genes) to identify the causal agent. Erysiphe quercicola was detected in 97% out of 140 samples, collected in six different orchards in the Malaga region. Among these, a small proportion also yielded E. alphitoides (8% of all samples) and E. alphitoides was found alone in 3% of samples. A phylogenetic approach was completed by cross inoculations between oak and mango, which led to typical symptoms, supporting the conspecificity of oak and mango powdery mildews. To our knowledge, this is the first report of E. quercicola and E. alphitoides causing powdery mildew on mango trees in mainland Spain, and thus mainland Europe, based on unequivocal phylogenetic and biological evidence. Our study thus confirmed the broad host range of both E. quercicola and E. alphitoides. These results have practical implications in terms of the demonstrated ability for host range expansion in powdery mildews. They also open interesting prospects to the elucidation of molecular mechanisms underlying the ability to infect single versus multiple and unrelated host plants since these two closely related powdery mildew species belong to a small clade with both generalist and specialist powdery mildews.


2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Reem M. Hassan ◽  
Dina M. Bassiouny ◽  
Yomna Matar

Kocuria kristinae is opportunistic Gram-positive cocci from the family Micrococcaceae. It is usually considered part of the normal flora that rarely is isolated from clinical specimens. Here, we report a case of Kocuria kristinae bacteremia; to the best of our knowledge, this is the first report from Egypt.


Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 276-276 ◽  
Author(s):  
W. Menzel ◽  
S. Winter ◽  
K. R. Richert-Pöggeler

Hollyhocks are popular garden plants and selected cultivars of Alcea rosea (family Malvaceae) are widespread in Germany. In spring 2009, dozens of A. rosea plants displaying strong vein clearing and veinal yellowing symptoms were found in private gardens in Hannover, Lower Saxony. Electron microscopic examinations of negatively stained adsorption preparations of five randomly selected samples of symptomatic plants or their offshoots revealed flexuous filamentous particles resembling those of potyviruses. Sap extracts also reacted strongly positive in an antigen coated plate (ACP)-ELISA with the broad-spectrum potyvirus antiserum AS-0573/I (DSMZ, Braunschweig, Germany). RNA extracts (RNeasy Kit, Qiagen, Valencia, CA) of the above mentioned leaf samples were used as templates in reverse transcription (RT)-PCR assays with potyvirus specific primers (2) that have been shown to amplify the 3′ terminus of the genome of many potyvirus species. For extracts from symptomatic samples, this resulted in a consistent amplification of an ~1.6-kbp fragment, whereas no products were obtained from RNA extracts of asymptomatic plants. From one positive sample, the amplified fragment was cloned and one clone was partially sequenced. The nucleotide (nt) and amino acid sequences showed the highest identities (81 to 83% and 87 to 90%, respectively) to GenBank sequences FJ539084, FM212972, EU884405, and FJ561293 of the potyvirus Malva vein clearing virus (MVCM). On the basis of these identity values and according to the species demarcation criteria in the genus Potyvirus, the virus can be regarded as a German isolate of the recently sequenced MVCV (3,4). Direct sequencing of the 5′-end of the amplified RT-PCR fragment revealed sequences of only one potyvirus species. The virus isolate has been submitted to the DSMZ Plant Virus Collection (Braunschweig, Germany) under accession PV-0963 and the sequence obtained from the cloned cDNA is deposited in GenBank (GQ856544). In addition, sap from affected leaves was mechanically inoculated onto sets of herbaceous indicator plants (Chenopodium quinoa, C. foliosum, C. murale, C. amaranticolor, Datura stramonium, Nicotiana benthamiana, N. hesperis, Petunia hybrida, and Solanum lycopersicum) of which only C. quinoa plants became infected. Symptoms of weak chlorosis along and beside veins of inoculated leaves, but not systemic leaves, became visible 2 weeks postinoculation. Symptomatic leaves contained flexuous filamentous particles and ACP-ELISA and RT-PCR confirmed virus presence. The partially sequenced amplicon showed 99% nt identity to the sequence from the cloned cDNA. To our knowledge, this is the first report of a MVCV isolate naturally occurring in A. rosea and C. quinoa is the first host identified that does not belong to the plant family Malvaceae. In contrast, the MVCV isolate used in the host range study of Lunello et al. (4) did not infect A. rosea and C. quinoa, confirming previous host range descriptions by Brunt et al. (1). Since MVCV infections of hollyhocks seem to cause only leaf symptoms and do not noticeably affect growth or flowering of the plants, this will hopefully not impair the usability of this popular garden plant. References: (1) A. A. Brunt et al. Descriptions and Lists from the VIDE Database. Online publication. Version: 16th January, 1997. (2) J. Chen et al. Arch. Virol. 146:757, 2001. (3) A. Hein Phytopathol. Z. 28:205, 1957. (4) P. Lunello et al. Virus Res. 140:91, 2009.


2018 ◽  
Vol 50 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Ilia Mariana Escobar-Avila ◽  
Edgar Óliver López-Villegas ◽  
Sergei A. Subbotin ◽  
Alejandro Tovar-Soto

2007 ◽  
Vol 189 (6) ◽  
pp. 2487-2496 ◽  
Author(s):  
Mohammad Y. Abajy ◽  
Jolanta Kopeć ◽  
Katarzyna Schiwon ◽  
Michal Burzynski ◽  
Mike Döring ◽  
...  

ABSTRACT Plasmid pIP501 has a very broad host range for conjugative transfer among a wide variety of gram-positive bacteria and gram-negative Escherichia coli. Functionality of the pIP501 transfer (tra) genes in E. coli was proven by pIP501 retrotransfer to Enterococcus faecalis (B. Kurenbach, C. Bohn, J. Prabhu, M. Abudukerim, U. Szewzyk, and E. Grohmann, Plasmid 50:86-93, 2003). The 15 pIP501 tra genes are organized in a single operon (B. Kurenbach, J. Kopeć, M. Mägdefrau, K. Andreas, W. Keller, C. Bohn, M. Y. Abajy, and E. Grohmann, Microbiology 152:637-645, 2006). The pIP501 tra operon is negatively autoregulated at the transcriptional level by the conjugative DNA relaxase TraA. Three of the 15 pIP501-encoded Tra proteins show significant sequence similarity to the Agrobacterium type IV secretion system proteins VirB1, VirB4, and VirD4. Here we report a comprehensive protein-protein interaction map of all of the pIP501-encoded Tra proteins determined by the yeast two-hybrid assay. Most of the interactions were verified in vitro by isolation of the protein complexes with pull-down assays. In conjunction with known or postulated functions of the pIP501-encoded Tra proteins and computer-assisted prediction of their cellular location, we propose a model for the first type IV-secretion-like system encoded by a conjugative plasmid from gram-positive bacteria.


2006 ◽  
Vol 72 (10) ◽  
pp. 6687-6692 ◽  
Author(s):  
Sanin Musovic ◽  
Gunnar Oregaard ◽  
Niels Kroer ◽  
Søren J. Sørensen

ABSTRACTThe host range and transfer frequency of an IncP-1 plasmid (pKJK10) among indigenous bacteria in the barley rhizosphere was investigated. A new flow cytometry-based cultivation-independent method for enumeration and sorting of transconjugants for subsequent 16S rRNA gene classification was used. Indigenous transconjugant rhizosphere bacteria were collected by fluorescence-activated cell sorting and identified by cloning and sequencing of 16S rRNA genes from the sorted cells. The host range of the pKJK10 plasmid was exceptionally broad, as it included not only bacteria belonging to the alpha, beta, and gamma subclasses of theProteobacteria, but alsoArthrobactersp., a gram-positive member of theActinobacteria. The transfer frequency (transconjugants per donor) from thePseudomonas putidadonor to the indigenous bacteria was 7.03 × 10−2± 3.84 × 10−2. This is the first direct documentation of conjugal transfer between gram-negative donor and gram-positive recipient bacteria in situ.


Of a comprehensive set of alkylating agents tested, only two, namely, ethyl methane sulphonate and diethyl sulphate, have been found so to interact with T 2 bacteriophage that cells of Escherichia coli , infected with phage treated extracellularly, manifest a considerably increased likelihood of yielding mutated phage. Since this increase can occur where the infective titre of the phage and the latent period and average burst size of the infected bacteria remain unchanged, it is considered that the increased mutation rate is a direct consequence of the chemical treatment, although the alkylation itself does not constitute the mutation. A study of the manner of inactivation of the phage by these agents has not revealed any characteristic difference between ethylation and other alkylations which could be held to account for its apparent uniqueness.


Plant Disease ◽  
2013 ◽  
Vol 97 (10) ◽  
pp. 1308-1315 ◽  
Author(s):  
Qin Peng ◽  
Yihui Yuan ◽  
Meiying Gao

Ginger rhizome rot is a major factor limiting the yield and marketability of ginger in Shandong Province, China. In order to identify the pathogen causing ginger rhizome rot, evaluate its pathogenicity, and explore its pathogenesis, diseased ginger rhizomes and surrounding soils were collected. A gram-positive, spore-forming, rod-shaped bacterium, designated GR8, was frequently isolated from the ginger rhizome samples. The bacterium was identified as Bacillus pumilus based on physio-biochemical and molecular biology characteristics. Pathogenicity studies with GR8 showed that it could cause disease of the tested rhizomes slices and the entire rhizome when wounded but no disease occurred when the rhizome was not wounded. Preliminary pathogenicity studies demonstrated that cell-free cultures of GR8 could not cause any disease symptoms, whereas the bacterial suspensions caused severe symptoms. The pathology studies revealed that infection of GR8 could cause starch grains to shrink from normal size, and destroy the parenchyma cells by invading and propagating in them. This is the first report of B. pumilus causing ginger rhizome rot.


1994 ◽  
Vol 40 (6) ◽  
pp. 864-866 ◽  
Author(s):  
Miroslav P�tek ◽  
Alena ?roglov� ◽  
Vera Becv�rov� ◽  
Jan Ne?vera ◽  
Jitka Hochmannov�

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