M. H. Malamy

Enhanced production of arginine and urea by genetically engineered Escherichia coli K-12 strains.

Tuchman, M, Rajagopal, B S, McCann, M T, Malamy, M H

Escherichia coli strains capable of enhanced synthesis of arginine and urea were produced by derepression of the arginine regulon and simultaneous overexpression of the E. coli carAB and argI genes...

Cryptic tetracycline resistance determinant (class F) from Bacteroides fragilis mediates resistance in Escherichia coli by actively reducing tetracycline accumulation.

Park, B H, Hendricks, M, Malamy, M H, Tally, F P, Levy, S B

Escherichia coli bearing a cryptic tetracycline resistance determinant from Bacteroides fragilis expressed low-level constitutive resistance to tetracycline under aerobic, but not anaerobic, growth...

Beta-lactamase-mediated imipenem resistance in Bacteroides fragilis.

Cuchural, G J, Malamy, M H, Tally, F P

Imipenem has excellent antimicrobial activity owing in part to beta-lactamase stability. We found that only 2 of over 350 Bacteroides fragilis group clinical isolates were resistant to imipenem, with...

Requirements for strand- and site-specific cleavage within the oriT region of Tn4399, a mobilizing transposon from Bacteroides fragilis.

Murphy, C G, Malamy, M H

Replicons that contain Tn4399, a conjugal mobilizing transposon isolated from Bacteroides fragilis, can be mobilized in the presence of broad-host-range IncP plasmids RP4 and R751 in Escherichia coli...

Sequence homology of clindamycin resistance determinants in clinical isolates of Bacteroides spp.

Marsh, P K, Malamy, M H, Shimell, M J, Tally, F P

The sequence homology of clindamycin resistance (Clnr) determinants was studied in 16 Clnr Bacteroides strains. The isolates were surveyed for plasmid content, homology with the Clnr determinant of...

Characterization of a "mobilization cassette" in transposon Tn4399 from Bacteroides fragilis.

Murphy, C G, Malamy, M H

Derivatives of nonconjugal plasmids that carry Tn4399, a transposon isolated from Bacteroides fragilis, can be mobilized for transfer by the broad-host-range IncP plasmids pRK231 or R751 in...

Sequencing the gene for an imipenem-cefoxitin-hydrolyzing enzyme (CfiA) from Bacteroides fragilis TAL2480 reveals strong similarity between CfiA and Bacillus cereus beta-lactamase II.

Thompson, J S, Malamy, M H

Using a newly constructed Bacteroides fragilis-Escherichia coli cloning shuttle vector, pJST61, we have cloned the cefoxitin (FOX)-imipenem (IMP) resistance determinant from B. fragilis TAL2480....

Cloning and expression of the Bacteroides fragilis TAL2480 neuraminidase gene, nanH, in Escherichia coli.

Russo, T A, Thompson, J S, Godoy, V G, Malamy, M H

We have cloned the Bacteroides fragilis TAL2480 neuraminidase (NANase) structural gene, nanH, in Escherichia coli. This was accomplished by using the cloning shuttle vector pJST61 and a partial Sau3A...

Tn4399, a conjugal mobilizing transposon of Bacteroides fragilis.

Hecht, D W, Malamy, M H

Conjugal transposons play an important role in the dissemination of antibiotic resistance determinants in the streptococci and have been postulated to exist in Bacteroides fragilis. To investigate...

Conjugal transfer of antibiotic resistance factors in Bacteroides fragilis: the btgA and btgB genes of plasmid pBFTM10 are required for its transfer from Bacteroides fragilis and for its mobilization by IncP beta plasmid R751 in Escherichia coli.

Hecht, D W, Jagielo, T J, Malamy, M H

Transferable plasmids play an important role in the dissemination of clindamycin-erythromycin resistance in Bacteroides fragilis. We previously described the isolation and properties of pBFTM10, a...

Regulation of the F-factor pif operon: pifO, a site required in cis for autoregulation, titrates the pifC product in trans.

Miller, J F, Malamy, M H

F factor pifC, pifA, and pifB gene expression is subject to negative regulation by the product of the pifC locus (J.F. Miller and M. H. Malamy, J. Bacteriol. 156:338-347, 1983). In this paper, we...

Identification of the pifC gene and its role in negative control of F factor pif gene expression.

Miller, J F, Malamy, M H

The pif region of the F factor includes two genes, pifA and pifB, that lead to abortive T7 infection. We have identified a new gene in this region, pifC, by constructing an in vitro fusion of pif DNA...

Inducible plasmid-determined resistance to arsenate, arsenite, and antimony (III) in escherichia coli and Staphylococcus aureus.

Silver, S, Budd, K, Leahy, K M, Shaw, W V, Hammond, D, Novick, R P, ...

Plasmids in both Escherichia coli and Staphylococcus aureus contain an "operon" that confers resistance to arsenate, arsenite, and antimony(III) salts. The systems were always inducible. All three...

F factor inhibition of conjugal transfer of broad-host-range plasmid RP4: requirement for the protein product of pif operon regulatory gene pifC.

Miller, J F, Lanka, E, Malamy, M H

By the use of deletions, point mutations, and gene fusions, we show that the protein product of the F factor pifC gene is responsible for F factor inhibition of plasmid RP4 conjugal transfer....

Tn4400, a compound transposon isolated from Bacteroides fragilis, functions in Escherichia coli.

Robillard, N J, Tally, F P, Malamy, M H

Transfer factor pBFTM10, isolated from the obligate anaerobic bacterium Bacteroides fragilis, carries a clindamycin resistance determinant which we have suggested is part of a transposable element....

Characterization of pBFTM10, a clindamycin-erythromycin resistance transfer factor from Bacteroides fragilis.

Tally, F P, Snydman, D R, Shimell, M J, Malamy, M H

Bacteroides fragilis TMP10, which is clindamycin-erythromycin resistant (Clnr) and tetracycline resistant (Tetr), contains several plasmids and is capable of transferring drug resistance markers to...

Hybridization studies reveal homologies between pBF4 and pBFTM10, Two clindamycin-erythromycin resistance transfer plasmids of Bacteroides fragilis.

Shimell, M J, Smith, C J, Tally, F P, Macrina, F L, Malamy, M H

Two clindamycin-erythromycin resistance transfer factors of Bacteroides fragilis, pBF4 and pBFTM10, were analyzed for regions of DNA homology. Although the plasmids were derived from different...

Control of the synthesis of alkaline phosphatase and the phosphate-binding protein in Escherichia coli.

Willsky, G R, Malamy, M H

Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunological techniques, we have compared the synthesis of the phoA protein (alkaline phosphatase) and the phoS protein...

A role for Bacteroides fragilis neuraminidase in bacterial growth in two model systems.

Godoy, V G, Dallas, M M, Russo, T A, Malamy, M H

Two Bacteroides fragilis neuraminidase-deficient mutants were used to study the role of neuraminidase activity in growth of B. fragilis in tissue culture monolayers (CHO cells) and in the in vivo rat...

Transfer of beta-lactamase-associated cefoxitin resistance in Bacteroides fragilis.

Cuchural, G J, Tally, F P, Storey, J R, Malamy, M H

A cefoxitin-resistant Bacteroides fragilis isolate, TAL 4170, which inactivates cefoxitin, was able to transfer beta-lactamase-mediated cefoxitin resistance to a susceptible B. fragilis recipient....

Characterization of two genetically separable inorganic phosphate transport systems in Escherichia coli.

Willsky, G R, Malamy, M H

Inorganic phosphate (Pi) transport by wild-type cells of Escherichia coli grown in excess phosphate-containing media involves two genetically separable transport systems. Cells dependent upon the...

Effect of arsenate on inorganic phosphate transport in Escherichia coli.

Willsky, G R, Malamy, M H

The effect of arsenate on strains dependent on the two major inorganic phosphate (Pi) transport systems in Escherichia coli was examined in cells grown in 1 mM phosphate medium. The development of...

Characterization of the termini and transposition products of Tn4399, a conjugal mobilizing transposon of Bacteroides fragilis.

Hecht, D W, Thompson, J S, Malamy, M H

We have isolated a 9.6-kilobase conjugal transposon, Tn4399 from Bacteroides fragilis, that is capable of mobilizing nonconjugal plasmids in cis. Here we characterize the ends of the transposon, its...

Mutational and in vivo methylation analysis of F-factor PifC protein binding to the pif operator and the region containing the primary origin of mini-F replication.

Miller, J F, Malamy, M H

We have used in vivo methods to identify multiple DNA-binding sites for the negatively autoregulated mini-F replication factor PifC. Sequence analysis of pif operator constitutive mutants, isolated...

Cloning of the pif region of the F sex factor and identification of a pif protein product.

Rotman, G S, Cooney, R, Malamy, M H

This paper reports a detailed investigation of the pif region of the F factor responsible for inhibition of development of T7 and related "female-specific" phages. We have mapped a series of pif::Tn5...

A new insertion sequence, IS121, is found on the Mu dI1 (Ap lac) bacteriophage and the Escherichia coli K-12 chromosome.

O'Connor, M B, Malamy, M H

We have discovered a new insertion sequence, now designated IS121, as a component of the Mu dI1 (Ap lac) phage. This sequence is 1.2 kilobases long and contains single recognition sites for the...

Enhanced production of arginine and urea by genetically engineered Escherichia coli K-12 strains.

Tuchman, M, Rajagopal, B S, McCann, M T, Malamy, M H

Escherichia coli strains capable of enhanced synthesis of arginine and urea were produced by derepression of the arginine regulon and simultaneous overexpression of the E. coli carAB and argI genes...

Cryptic tetracycline resistance determinant (class F) from Bacteroides fragilis mediates resistance in Escherichia coli by actively reducing tetracycline accumulation.

Park, B H, Hendricks, M, Malamy, M H, Tally, F P, Levy, S B

Escherichia coli bearing a cryptic tetracycline resistance determinant from Bacteroides fragilis expressed low-level constitutive resistance to tetracycline under aerobic, but not anaerobic, growth...

Beta-lactamase-mediated imipenem resistance in Bacteroides fragilis.

Cuchural, G J, Malamy, M H, Tally, F P

Imipenem has excellent antimicrobial activity owing in part to beta-lactamase stability. We found that only 2 of over 350 Bacteroides fragilis group clinical isolates were resistant to imipenem, with...

Requirements for strand- and site-specific cleavage within the oriT region of Tn4399, a mobilizing transposon from Bacteroides fragilis.

Murphy, C G, Malamy, M H

Replicons that contain Tn4399, a conjugal mobilizing transposon isolated from Bacteroides fragilis, can be mobilized in the presence of broad-host-range IncP plasmids RP4 and R751 in Escherichia coli...

Sequence homology of clindamycin resistance determinants in clinical isolates of Bacteroides spp.

Marsh, P K, Malamy, M H, Shimell, M J, Tally, F P

The sequence homology of clindamycin resistance (Clnr) determinants was studied in 16 Clnr Bacteroides strains. The isolates were surveyed for plasmid content, homology with the Clnr determinant of...

Characterization of a "mobilization cassette" in transposon Tn4399 from Bacteroides fragilis.

Murphy, C G, Malamy, M H

Derivatives of nonconjugal plasmids that carry Tn4399, a transposon isolated from Bacteroides fragilis, can be mobilized for transfer by the broad-host-range IncP plasmids pRK231 or R751 in...

Sequencing the gene for an imipenem-cefoxitin-hydrolyzing enzyme (CfiA) from Bacteroides fragilis TAL2480 reveals strong similarity between CfiA and Bacillus cereus beta-lactamase II.

Thompson, J S, Malamy, M H

Using a newly constructed Bacteroides fragilis-Escherichia coli cloning shuttle vector, pJST61, we have cloned the cefoxitin (FOX)-imipenem (IMP) resistance determinant from B. fragilis TAL2480....

Cloning and expression of the Bacteroides fragilis TAL2480 neuraminidase gene, nanH, in Escherichia coli.

Russo, T A, Thompson, J S, Godoy, V G, Malamy, M H

We have cloned the Bacteroides fragilis TAL2480 neuraminidase (NANase) structural gene, nanH, in Escherichia coli. This was accomplished by using the cloning shuttle vector pJST61 and a partial Sau3A...

Tn4399, a conjugal mobilizing transposon of Bacteroides fragilis.

Hecht, D W, Malamy, M H

Conjugal transposons play an important role in the dissemination of antibiotic resistance determinants in the streptococci and have been postulated to exist in Bacteroides fragilis. To investigate...

Conjugal transfer of antibiotic resistance factors in Bacteroides fragilis: the btgA and btgB genes of plasmid pBFTM10 are required for its transfer from Bacteroides fragilis and for its mobilization by IncP beta plasmid R751 in Escherichia coli.

Hecht, D W, Jagielo, T J, Malamy, M H

Transferable plasmids play an important role in the dissemination of clindamycin-erythromycin resistance in Bacteroides fragilis. We previously described the isolation and properties of pBFTM10, a...

Regulation of the F-factor pif operon: pifO, a site required in cis for autoregulation, titrates the pifC product in trans.

Miller, J F, Malamy, M H

F factor pifC, pifA, and pifB gene expression is subject to negative regulation by the product of the pifC locus (J.F. Miller and M. H. Malamy, J. Bacteriol. 156:338-347, 1983). In this paper, we...

Identification of the pifC gene and its role in negative control of F factor pif gene expression.

Miller, J F, Malamy, M H

The pif region of the F factor includes two genes, pifA and pifB, that lead to abortive T7 infection. We have identified a new gene in this region, pifC, by constructing an in vitro fusion of pif DNA...

Inducible plasmid-determined resistance to arsenate, arsenite, and antimony (III) in escherichia coli and Staphylococcus aureus.

Silver, S, Budd, K, Leahy, K M, Shaw, W V, Hammond, D, Novick, R P, ...

Plasmids in both Escherichia coli and Staphylococcus aureus contain an "operon" that confers resistance to arsenate, arsenite, and antimony(III) salts. The systems were always inducible. All three...

Cloning of the pif region of the F sex factor and identification of a pif protein product.

Rotman, G S, Cooney, R, Malamy, M H

This paper reports a detailed investigation of the pif region of the F factor responsible for inhibition of development of T7 and related "female-specific" phages. We have mapped a series of pif::Tn5...

A new insertion sequence, IS121, is found on the Mu dI1 (Ap lac) bacteriophage and the Escherichia coli K-12 chromosome.

O'Connor, M B, Malamy, M H

We have discovered a new insertion sequence, now designated IS121, as a component of the Mu dI1 (Ap lac) phage. This sequence is 1.2 kilobases long and contains single recognition sites for the...

F factor inhibition of conjugal transfer of broad-host-range plasmid RP4: requirement for the protein product of pif operon regulatory gene pifC.

Miller, J F, Lanka, E, Malamy, M H

By the use of deletions, point mutations, and gene fusions, we show that the protein product of the F factor pifC gene is responsible for F factor inhibition of plasmid RP4 conjugal transfer....

Tn4400, a compound transposon isolated from Bacteroides fragilis, functions in Escherichia coli.

Robillard, N J, Tally, F P, Malamy, M H

Transfer factor pBFTM10, isolated from the obligate anaerobic bacterium Bacteroides fragilis, carries a clindamycin resistance determinant which we have suggested is part of a transposable element....

Characterization of pBFTM10, a clindamycin-erythromycin resistance transfer factor from Bacteroides fragilis.

Tally, F P, Snydman, D R, Shimell, M J, Malamy, M H

Bacteroides fragilis TMP10, which is clindamycin-erythromycin resistant (Clnr) and tetracycline resistant (Tetr), contains several plasmids and is capable of transferring drug resistance markers to...

Hybridization studies reveal homologies between pBF4 and pBFTM10, Two clindamycin-erythromycin resistance transfer plasmids of Bacteroides fragilis.

Shimell, M J, Smith, C J, Tally, F P, Macrina, F L, Malamy, M H

Two clindamycin-erythromycin resistance transfer factors of Bacteroides fragilis, pBF4 and pBFTM10, were analyzed for regions of DNA homology. Although the plasmids were derived from different...

Control of the synthesis of alkaline phosphatase and the phosphate-binding protein in Escherichia coli.

Willsky, G R, Malamy, M H

Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunological techniques, we have compared the synthesis of the phoA protein (alkaline phosphatase) and the phoS protein...

A role for Bacteroides fragilis neuraminidase in bacterial growth in two model systems.

Godoy, V G, Dallas, M M, Russo, T A, Malamy, M H

Two Bacteroides fragilis neuraminidase-deficient mutants were used to study the role of neuraminidase activity in growth of B. fragilis in tissue culture monolayers (CHO cells) and in the in vivo rat...

Transfer of beta-lactamase-associated cefoxitin resistance in Bacteroides fragilis.

Cuchural, G J, Tally, F P, Storey, J R, Malamy, M H

A cefoxitin-resistant Bacteroides fragilis isolate, TAL 4170, which inactivates cefoxitin, was able to transfer beta-lactamase-mediated cefoxitin resistance to a susceptible B. fragilis recipient....

Characterization of two genetically separable inorganic phosphate transport systems in Escherichia coli.

Willsky, G R, Malamy, M H

Inorganic phosphate (Pi) transport by wild-type cells of Escherichia coli grown in excess phosphate-containing media involves two genetically separable transport systems. Cells dependent upon the...

Effect of arsenate on inorganic phosphate transport in Escherichia coli.

Willsky, G R, Malamy, M H

The effect of arsenate on strains dependent on the two major inorganic phosphate (Pi) transport systems in Escherichia coli was examined in cells grown in 1 mM phosphate medium. The development of...

Characterization of the termini and transposition products of Tn4399, a conjugal mobilizing transposon of Bacteroides fragilis.

Hecht, D W, Thompson, J S, Malamy, M H

We have isolated a 9.6-kilobase conjugal transposon, Tn4399 from Bacteroides fragilis, that is capable of mobilizing nonconjugal plasmids in cis. Here we characterize the ends of the transposon, its...

Mutational and in vivo methylation analysis of F-factor PifC protein binding to the pif operator and the region containing the primary origin of mini-F replication.

Miller, J F, Malamy, M H

We have used in vivo methods to identify multiple DNA-binding sites for the negatively autoregulated mini-F replication factor PifC. Sequence analysis of pif operator constitutive mutants, isolated...