Publications

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adsorption of mycobacteriophage d29 on mycobacterium leprae. 1978358889
interaction of mycobacterium leprae and mycobacteriophage d29.this study of the interaction between mycobacterium leprae and the mycobacteriophage d29 showed that the viruses caused a patchy damage of cell wall structure and the accumulation in the host of internal crystalline structures. whether the observed ultrastructural alterations were caused by the replication of d29 was not clear. mitomycin c also caused the accumulation of crystalline structures in m. leprae.1978382947
chemical and physical properties of mycobacteriophage d29.mycobacteriophage d29 has a head of uniform size (average diameter 65 nm) and regular shape and a tail of variable length. the stability of the bacteriophage is optimal between ph 9 and 10. the virus contain double-stranded dna and six structural polypeptides, three major and three minor. the molecular weights of these six polypeptides, as determined by polyacrylamide gel electrophoresis in the presence of dodecylsulfate, are 150 000, 138 000, 13 000, 66 000 and 24 000. the virus contains no lip ...1977837938
a stable escherichia coli-mycobacterium smegmatis plasmid shuttle vector containing the mycobacteriophage d29 origin.a plasmid shuttle vector for escherichia coli and mycobacteria was constructed from an e. coli plasmid containing the cole1 origin, a 2.6-kb psti fragment from bacteriophage d29 that grows in numerous mycobacterial species, and the kanamycin resistance gene either of tn903 or of tn5. the resultant plasmid is 7.63 kb and can be introduced via transformation into mycobacterium smegmatis with high efficiency. in m. smegmatis the plasmid is stable and apparently present in multiple copies. biolumine ...19921334270
isolation and characterization of temperature sensitive mutants of the f5 deletion mutant of mycobacteriophage d29.seven thermosensitive mutants of the f5 deletion mutant of the mycobacteriophage d29 were described. the mutants were obtained using n-methyl-n'-nitro-n-nitrosoguanidine (mnng) mutagenesis, and were characterized using temperature shift assays, complementation and recombination tests, electron microscopy of infected host bacteria at non-permissive temperature, and serum blocking power. mutants deficient in tail assembly, and mutants deficient in head and tail assembly were described. mutants def ...19911930565
restriction map of mycobacteriophage d29 and its deletion mutant f5.a physical map of mycobacteriophage d29 was constructed, including positions for 25 restriction sites for 9 endunocleasic enzymes. d29 dna contains about 48 150 bp. analysis of a deletion mutant (f5) has allowed to determine the location of two non essential regions in the genome, allowing further insertion of foreign genes and construction of cosmids.19892503994
action of colistin (polymyxin e) on the lytic cycle of the mycobacteriophage d29 in mycobacterium tuberculosis.the antibiotic colistin (polymyxin e) inhibited the lytic cycle of the mycobacteriophage d29 in the tubercle bacilli, but not the d29 adsorption. the protein and nucleic acid synthesis in d29-infected bacteria were not affected significantly. the inhibitory activity was reversed by washing off the antibiotic, and by addition of ca++, but not in media made iso-osmotic by addition of nacl or sucrose. transmission electron microscopy revealed an asymmetric to symmetric transition in the staining pr ...19863097989
studies on clofazimine-resistance in mycobacteria: is the inability to isolate drug-resistance mutants related to its mode of action?this study showed that clofazimine was not radiomimetic, it was not a mutagenic compound, it was not an inducer of prophage-lambda, and it did not eliminate plasmids from appropriate host bacteria. the drug caused an effective inhibition of the growth of mycobacterium aurum, and also inhibited the growth cycle of the mycobacteriophage d29. cross-resistance between clofazimine, streptomycin and rifampicin could not be demonstrated. drug-resistance mutants towards clofazimine could not be isolated ...19873122464
further studies on the inactivation of mycobacteriophage d29 by chloroform. 19734583540
the occurrence of lipids in mycobacteriophage d29 propagated in mycobacterium smegmatis atcc 607. 19705475679
biosynthesis of a lipase by mycobacterium smegmatis atcc 607 infected by mycobacteriophage d29. 19705475680
inhibition by fifampin of mycobacteriophage d29 replication in its drug-resistant host, mycobacterium smergmatis atcc 607. 19715579905
abortive infection of mycobacterium leprae by the mycobacteriophage d29.the interactions of mycobacteriophage d29 and mycobacterium leprae were examined. it was demonstrated that after adsorption d29 injected its dna in m. leprae. while the synthesis of host proteins and lipids were inhibited in m. tuberculosis and in m. smegmatis during infection by d29, the results were inconclusive in the case of m. leprae because these bacteria did not incorporate the appropriate substrates.19846399068
further observations on the mycobacteriophage d29-mycobacterial interactions. 19846442822
paracrystalline inclusions in mycobacterium leprae.the occurrence of paracrystalline inclusions of mycobacterium leprae infected with the mycobacteriophage d29 or treated with mitomycin c was reported before [5, 6]. in pursuing these studies we have now documented by electron micrography a number of paracrystals we thought sufficient to further describe these inclusions, and to show that they appeared to be formed in association with the intracellular membranous structures of the leprosy bacilli.19817020523
effects of antituberculosis and antileprosy drugs on mycobacteriophage d29 growth.the minimal inhibitory concentrations of antituberculosis and antileprosy drugs were determined for mycobacterium aurum. the concentrations that reduced the final yield of bacteriophage d29r1 by 50% and the time during the replication cycle at which the drugs completely inhibited phage production were estimated. the 50% inhibitory concentration/minimal inhibitory concentration ratios were close to 1.0 for clofazimine, colistin, rifampin, and streptomycin; these ratios were high for dapsone (diam ...19807447413
new pyruvylated, glycosylated acyltrehaloses from mycobacterium smegmatis strains, and their implications for phage resistance in mycobacteria.phage resistance and apparent lysogenization of mycobacterium smegmatis due to infection with mycobacteriophage d29 results in the emergence of new variations of the pyruvylated, acylated trehaloses described by saadat and ballou, j. biol. chem. 258 (1983) 1813-1818. thin-layer chromatography of the glycolipids from two strains of phage-resistant m. smegmatis (mc(2)22 and mc(2)11) and comparison with those from phage-sensitive strains revealed a new, more mobile glycolipid in each case. the stru ...19948149383
construction of d29 shuttle phasmids and luciferase reporter phages for detection of mycobacteria.diseases caused by mycobacterium tuberculosis, m. leprae and m. avium, cause significant morbidity and mortality worldwide. effective treatments require that the organisms be speciated and that drug susceptibilities for the causative organisms be characterized. reporter phage technology has been developed as a rapid and convenient method for identifying mycobacterial species and evaluating drug resistance. in this report we describe the construction of luciferase reporter phages from mycobacteri ...19968996097
mycobacteriophage d29 contains an integration system similar to that of the temperate mycobacteriophage l5.a mycobacteriophage d29 dna fragment cloned in prm64, a shuttle plasmid that transforms mycobacterium smegmatis, was sequenced. the determined sequence was 2592 nucleotides long and had a mean g+c content of 63.7 mol%, similar to that of mycobacterial dna. four orfs were identified: one with strong homology to dcmp deaminase genes; one homologous to mycobacteriophage l5 gene 36, whose function is unknown; one encoding a possible excisase; and one encoding an integrase. the intergenic region betw ...19979274023
genome structure of mycobacteriophage d29: implications for phage evolution.mycobacteriophage d29 is a lytic phage that infects both fast and slow-growing mycobacterial species. the complete genome sequence of d29 reveals that it is a close relative of the temperate mycobacteriophage l5, whose sequence has been described previously. the overall organization of the d29 genome is similar to that of l5, although a 3.6 kb deletion removing the repressor gene accounts for the inability of d29 to form lysogens. comparison of the two genomes shows that they are punctuated by a ...19989636706
inactivation of mycobacteriophage d29 using ferrous ammonium sulphate as a tool for the detection of viable mycobacterium smegmatis and m. tuberculosis.there is still an urgent requirement for more sensitive, cost-effective methods for detection and susceptibility testing of mycobacteria in clinical samples. we have been investigating a simple bacteriophage-based system which could be used for both purposes. as this depends upon the detection of phages which have successfully infected cells, a key step is the efficient removal or inactivation of phages remaining free in the culture medium. we demonstrate here the use of ferrous ammonium sulphat ...19989766200
mycobacteriophage d29 integrase-mediated recombination: specificity of mycobacteriophage integration.mycobacteriophage d29 is a lytic phage that infects both fast- and slow-growing species of the mycobacteria. d29 forms clear plaques on lawns of mycobacterium smegmatis and mycobacterium bovis bacille calmette-guérin (bcg) in which a very high proportion of infected cells are killed. however, genomic analysis of d29 demonstrates that it is a close relative of the temperate mycobacteriophage l5, and is presumably a non-temperate derivative of a temperate parent. the d29 genome encodes a putative ...19989931474
development of a bacteriophage phage replication assay for diagnosis of pulmonary tuberculosis.successful infection and replication of bacteriophages is indicative of the presence of viable bacteria. we describe here the development of a bacteriophage replication assay for the detection of mycobacterium tuberculosis by using mycobacteriophage d29. optimization of phage inoculate and incubation times allowed highly sensitive detection of m. bovis bcg. fewer than 10 cfu (100 cfu/ml) were detected. no false-positive results were observed in negative samples. application of the assay to 496 s ...200415131178
low-cost rapid detection of rifampicin resistant tuberculosis using bacteriophage in kampala, uganda.resistance to anti-tuberculosis drugs is a serious public health problem. multi-drug resistant tuberculosis (mdr-tb), defined as resistance to at least rifampicin and isoniazid, has been reported in all regions of the world. current phenotypic methods of assessing drug susceptibility of m. tuberculosis are slow. rapid molecular methods to detect resistance to rifampicin have been developed but they are not affordable in some high prevalence countries such as those in sub saharan africa. a simple ...200717212825
evaluation of rifampicin and isoniazid susceptibility testing of mycobacterium tuberculosis by a mycobacteriophage d29-based assay.conventional methods for determining drug susceptibility of mycobacterium tuberculosis require several weeks to obtain results, limiting their usefulness; automated methods and those based on molecular biology techniques have been able to reduce the turnaround time, but their high cost and need for sophisticated equipment restrict their use in developing countries. the goal of the present study was to evaluate the diagnostic accuracy of a rapid (3-4 days) low-cost test based on the use of mycoba ...200717314367
evaluation of killing kinetics of anti-tuberculosis drugs on mycobacterium tuberculosis using a bacteriophage-based assay.killing kinetics studies on mycobacterium tuberculosis are labour intensive and time consuming since it takes nearly 6-7 weeks to get the data from an experiment. a modified protocol is required to increase the throughput and expedite the results.200818772589
comparison of the performances of two in-house rapid methods for antitubercular drug susceptibility testing.resistance to rifampin (rifampicin), isoniazid, and streptomycin of 69 mycobacterium tuberculosis isolates was analyzed by an in-house method based on mycobacteriophage d29 and a colorimetric micromethod. both methods showed sensitivity and specificity values ranging from 93% to 100%. these simple methods offer an option for drug resistance assessment of m. tuberculosis.200919015333
the mycobacteriophage d29 gene 65 encodes an early-expressed protein that functions as a structure-specific nuclease.the genomes of mycobacteriophages of the l5 family, which includes the lytic phage d29, contain several genes putatively linked to dna synthesis. one such gene is 65, which encodes a protein belonging to the reca/dnab helicase superfamily. in this study a recombinant version of the mycobacteriophage d29 gp65 was functionally characterized. the results indicated that it is not a helicase as predicted but an exonuclease that removes 3' arms from forked structures in an atp-dependent manner. the gp ...200919028888
comparison of the performance of two mycobacteriophage d29-based protocols for fluoroquinolone susceptibility testing in mycobacterium tuberculosis.we tested a mycobacteriophage d29-based method for fluoroquinolone susceptibility assessment in clinical isolates of mycobacteriumtuberculosis. the method was incapable of identifying susceptible strains as such, although a slightly different published protocol successfully identified resistant and susceptible strains. thus, caution is necessary when choosing an "in-house" d29-based protocol for testing of drug resistance.200919846046
[expression and purification of lysin b in mycobacteriophage d29 and analysis of its enzymatic properties].lysinb (lysb) in mycobacteriophage d29 was cloned and expressed and its enzymatic properties were analysed. the lysb gene was amplified by pcr from mycobacteriophage d29 genomic dna and inserted into pet22b vector. the constructed recombinant plasmid was transformed into escherichia coli bl21(de3) to express fusion protein, which was purified by ni-nta column and enzymatic activity detected. the results showed that expression plasmid pet22b-lysb was constructed successfully. highly purified reco ...201020575441
the impact of relative humidity and collection media on mycobacteriophage d29 aerosol.this study was conducted to evaluate the effect of aerosol generation, methods of sampling, storage conditions and relative humidity on the culturability of the mycobacteriophage d29. the lytic phage d29 can kill mycobacterium tuberculosis and the phage aerosol can be treated as a potential tool for tuberculosis treatment. the culturability of d29 was tested using a test chamber designed for the bioaerosols research against three spray liquids (deionized water, pbs and normal saline), four colle ...201122194291
real-time pcr of mycobacteriophage for rapid phenotypic drug susceptibility results for m. tuberculosis.managing drug resistant mycobacterium tuberculosis (tb) requires drug susceptibility testing, yet conventional drug susceptibility testing is slow and molecular testing does not yield results for all antituberculous drugs. we addressed these challenges by utilizing real-time pcr of mycobacteriophage d29 dna to evaluate the drug resistance of clinical tb isolates. mycobacteriophages infect and replicate in viable bacterial cells faster than bacteria cells replicate, and have been used for detecti ...201122170929
mycobacteriophage d29 holin c-terminal region functionally assists in holin aggregation and bacterial cell death.holins are phage-encoded small transmembrane proteins that perforate the bacterial cytoplasmic membrane. in most cases, this process allows the phage-encoded peptidoglycan hydrolases to act on the cell wall, resulting in host cell lysis and phage release. we report a detailed functional characterization of mycobacterium phage d29 gp11 coding for a putative holin that, upon expression, rapidly kills both escherichia coli and mycobacterium smegmatis. we dissected gp11 by making several deletions a ...201626471254
molecular dissection of phage endolysin: an interdomain interaction confers host specificity in lysin a of mycobacterium phage d29.mycobacterium tuberculosis has always been recognized as one of the most successful pathogens. bacteriophages that attack and kill mycobacteria offer an alternate mechanism for the curtailment of this bacterium. upon infection, mycobacteriophages produce lysins that catalyze cell wall peptidoglycan hydrolysis and mycolic acid layer breakdown of the host resulting in bacterial cell rupture and virus release. the ability to lyse bacterial cells make lysins extremely significant. we report here a d ...201424627486
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