Vibriophage N4 DNA is nonpermuted and terminally redundant

1995 ◽  
Vol 41 (9) ◽  
pp. 842-845 ◽  
Author(s):  
Amar N. Ghosh ◽  
Bimal K. Chakrabarti ◽  
Dhruba J. Chattopadhyay ◽  
Susmita Sil
Keyword(s):  
Vibrio Cholerae ◽  
Phage Genome ◽  
Phage Typing ◽  
Electron Microscopic ◽  
Exonuclease Iii ◽  
Typing Scheme ◽  
Microscopic Studies ◽  
Partial Denaturation ◽  
Vibrio Cholerae O1

Phage N4 is one of the five newly isolated phages used in a new phage typing scheme for Vibrio cholerae O1 biovar EITor strains and belongs to the Podoviridae family. Electron microscopic studies showed that the phage N4 has a DNA of 40.4 ± 0.1 kb. A partial denaturation map of the N4 DNA has been constructed. It has been shown with the help of this partial denaturation map that phage N4 genome is nonpermuted. Circularization of the phage genome on treatment with exonuclease III, followed by incubation in 50% formamide, indicates a terminal redundancy.Key words: vibriophage N4, DNA, Vibrio cholerae, denaturation mapping.

New phage typing scheme for Vibrio cholerae O1 biotype El Tor strains.

1993 ◽  
Vol 31 (6) ◽  
pp. 1579-1585 ◽  
Author(s):  
D J Chattopadhyay ◽  
B L Sarkar ◽  
M Q Ansari ◽  
B K Chakrabarti ◽  
M K Roy ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Phage Typing ◽  
Typing Scheme ◽  
Vibrio Cholerae O1 ◽  
El Tor

scholarly journals Reduction in Capsular Content and Enhanced Bacterial Susceptibility to Serum Killing of Vibrio cholerae O139 Associated with the 2002 Cholera Epidemic in Bangladesh

2005 ◽  
Vol 73 (10) ◽  
pp. 6577-6583 ◽  
Author(s):  
Firdausi Qadri ◽  
Ann-Mari Svennerholm ◽  
Sohel Shamsuzzaman ◽  
Taufiqur Rahman Bhuiyan ◽  
Jason B. Harris ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Capsular Polysaccharide ◽  
Bactericidal Effect ◽  
Electron Microscopic ◽  
Recent Infection ◽  
Phenotypic Properties ◽  
Immunological Responses ◽  
Serum Killing ◽  
Vibrio Cholerae O139 ◽  
Microscopic Studies

ABSTRACT Vibrio cholerae O139 emerged in 1992 as a major cause of epidemic cholera. However, the incidence of disease due to this new serogroup subsequently decreased for almost a decade. In April 2002, there was a dramatic resurgence of V. cholerae O139 in Bangladesh. We compared the phenotypic properties of the bacterial isolates and the immunological responses in patients with disease due to V. cholerae O139 during the 2002 epidemic with those dating to the emergence of this disease in 1993 to 1995. Strains isolated from patients in the two time periods were compared with respect to capsular polysaccharide, their resistance to the bactericidal effect of serum, and their capacity to be used as target strains in complement-mediated vibriocidal assays. Phase-contrast microscopy showed that strains isolated in 2002 had less capsular material than those isolated from 1993 to 1995 (P = <0.001), a finding confirmed by electron microscopic studies. Strains isolated in 2002 were more susceptible to the bactericidal activity of serum compared to strains from 1993 to 1995 (P = 0.013). Compared to results using a standard O139 strain, a modified vibriocidal assay utilizing a 2002 strain, CIRS 134, as the target organism detected higher vibriocidal responses in both O139-infected cholera patients as well as O139 vaccine recipients. The vibriocidal assay utilizing the less encapsulated 2002 strain, CIRS 134, is a more sensitive indicator of adaptive immune responses to recent infection with V. cholerae O139. Consequently, this assay may be useful in studies of both O139-infected patients and recipients of O139 vaccines.

Electron Microscopic study of the polymyxin treated vibrio cholerae cells

1990 ◽  
Vol 48 (3) ◽  
pp. 642-643
Author(s):  
Tapas Kumar Mandal
Keyword(s):  
Vibrio Cholerae ◽  
Morphological Changes ◽  
Indian Subcontinent ◽  
Analytical Techniques ◽  
Polymyxin B ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Bacterial Organism ◽  
Polypeptide Antibiotic ◽  
Dose Dependent

Infections by Vibrio Cholerae (a gram-negative bacterial organism) in the Indian subcontinent are frequently encoutered. The polypeptide antibiotic polymyxin-B (PB) is a clinically important antibiotic which is used to treat infections caused by a number of gr am-negative bacteria. It has been observed that PB causes disruption of u U1rastructure of outer membrane (OW) , as revealed by the electron microscopic studies for a number of bacteria, through the formation of blebs and crenations (finger-like structures) on the OM . In this context, it is relevant to look specifically at the morphological changes induced by PB on Vibrio cells. PB produces dose dependent changes in the surface topography of pathogenic Vibrio cholerae cells. The susceptibilities of various vibrio strains to PB are also studied through analytical techniques.

scholarly journals Evaluation of a RAPD-based typing scheme in a molecular epidemiology study of Vibrio cholerae O1, Brazil

2004 ◽  
Vol 96 (3) ◽  
pp. 447-454 ◽  
Author(s):  
N.C. Leal ◽  
M. Sobreira ◽  
T.C. Leal-Balbino ◽  
A.M.P. Almeida ◽  
M.J.B. Silva ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Vibrio Cholerae ◽  
Epidemiology Study ◽  
Typing Scheme ◽  
Vibrio Cholerae O1

scholarly journals Development and Evaluation of a Phage Typing Scheme for Vibrio cholerae O139

2000 ◽  
Vol 38 (1) ◽  
pp. 44-49
Author(s):  
A. K. Chakrabarti ◽  
A. N. Ghosh ◽  
G. Balakrish Nair ◽  
S. K. Niyogi ◽  
S. K. Bhattacharya ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Phage Type ◽  
Phage Typing ◽  
Major Type ◽  
Dominant Type ◽  
Typing Scheme ◽  
Phage Types ◽  
Type 3

ABSTRACT The scenario of cholera that existed previously changed in 1992 and 1993 with the emergence of toxigenic Vibrio cholerae O139 in India. The genesis of the new serogroup formed the impetus to search for O139 phages in and around the country. A total of five newly isolated phages lytic to V. cholerae O139 strains were used for the development of this phage typing scheme. These phages differed from each other and also differed from the existing O1 phages in their lytic patterns, morphologies, restriction endonuclease digestion profiles, and immunological criteria. With this scheme, 500 V. cholerae O139 strains were evaluated for their phage types, and almost all strains were found to be typeable. The strains clustered into 10 different phage types, of which type 1 (38.2%) was the dominant type, followed by type 2 (22.4%) and type 3 (18%). Additionally, a comparative study of phage types in 1993 and 1994 versus those from 1996 to 1998 for O139 strains showed a higher percentage of phage type 1 (40.5%), followed by type 3 (18.8%) during the period between 1993 and 1994, whereas phage type 2 (32.1%) was the next major type during the period from 1996 to 1998. This scheme comprising five newly isolated phages would be another useful tool in the study of the epidemiology of cholera caused by V. cholerae O139.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

Early Development of Drug-Induced Hepatic Necrosis

1971 ◽  
Vol 29 ◽  
pp. 576-577
Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser
Keyword(s):  
Early Development ◽  
Hepatic Necrosis ◽  
Screening Tests ◽  
Dense Matrix ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Drug Induced ◽  
Hepatocellular Damage ◽  
Sprague Dawley Rats ◽  
Microscopic Studies

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.

Electron Microscopic identification of Pre-B Lymphocytes in the Bone Marrow of a Patient with Chronic Myelocytic Leukemic in Blast Crisis

1982 ◽  
Vol 40 ◽  
pp. 346-347
Author(s):  
T. Mullin ◽  
G. Yee ◽  
M. Aheam ◽  
J. Trujillo
Keyword(s):  
Blast Crisis ◽  
Immunoglobulin M ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Transformation Theory ◽  
Electron Microscopic ◽  
Chemotherapeutic Sensitivity ◽  
Microscopic Studies ◽  
Hematopoietic Precursor ◽  
Lymphoblastic Transformation ◽  
B Lineage

There have been numerous reports in the current literature suggesting that hematopoietic precursor cells in some human chronic myelocytic leukemias (CML) undergo lymphoblastic transformation at the time of the acute blast crisis (BC) stage. The primary evidence offered in support of this transformation theory--lymphoblastic appearing morphology, increased terminal deoxynucleotidyl transferase (TdT) activity, and chemotherapeutic sensitivity to vincristine and prednisone--has been indirect, however, since these features may occur in nonlymphoid cells. More direct support for the Pre-B lineage of these cells has recently been provided by immunofluorescent light microscopic studies demonstrating the presence of intracytoplasmic immunoglobulin M (IgM) in these CML-BC cells.

Sign in / Sign up

Export Citation Format

Share Document