Vaccines for bacterial sexually transmitted infections: a realistic goal?
Sparling, P F, Elkins, C, Wyrick, P B, Cohen, M S
Bacterial infections of the genital tract (gonorrhea, chlamydia, chancroid, syphilis) are common and cause significant morbidity. Their importance is heightened by recent appreciation of their roles...
Turner, Paul C., Thomas, Christopher E., Elkins, Christopher, Clary, Susan, Sparling, P. F.
Many bacterial pathogens, including pathogenic neisseriae, can use heme as an iron source for growth. To study heme utilization by Neisseria gonorrhoeae, two heme biosynthetic mutants were...
Antioxidant enzymes are thought to be important for the survival of pathogenic Neisseria species. We isolated a glutathione peroxidase-related gene (gpxA) from Neisseria meningitidis FAM20. The N....
Characterization of lbpA, the structural gene for a lactoferrin receptor in Neisseria gonorrhoeae.
Neisseria gonorrhoeae acquires iron (Fe) efficiently from lactoferrin (LF). A 103-kDa gonococcal outer membrane LF-binding protein (Lbp) was identified previously. We isolated the structural gene...
Aebi, C, Stone, B, Beucher, M, Cope, L D, Maciver, I, Thomas, S E, ...
The amino acid sequence of the cell-surface-exposed, 81-kDa CopB outer membrane protein of Moraxella catarrhalis was found to be similar to those of TonB-dependent outer membrane proteins of other...
Chen, C J, Sparling, P F, Lewis, L A, Dyer, D W, Elkins, C
The majority of in vitro-grown Neisseria gonorrhoeae strains were unable to use hemoglobin as the sole source of iron for growth (Hgb-), but a minor population was able to do so (Hgb+). The ability...
Cohen, M S, Chai, Y, Britigan, B E, McKenna, W, Adams, J, Svendsen, T, ...
The quinone antibiotic streptonigrin is believed to kill bacteria by promoting formation of oxygen radicals. This antibiotic has also been used to select resistant bacterial mutants, some of which...
Cornelissen, C N, Anderson, J E, Sparling, P F
The molecular weight heterogeneities of Tbp1 and Tbp2 among a panel of 45 gonococcal isolates were assessed. The tbpB genes from four of these strains were sequenced to characterize the Tbp2 sequence...
FrpB (for Fe-regulated protein B) is a 76-kDa outer membrane protein that is part of the iron regulon of Neisseria gonorrhoeae and Neisseria meningitidis. The frpB gene from gonococcal strain FA19...
Cornelissen, C N, Sparling, P F
Neisseria gonorrhoeae is capable of iron utilization from human transferrin in a receptor-mediated event. Transferrin-binding protein 1 (Tbp1) and Tbp2 have been implicated in transferrin receptor...
Isolation and analysis of a fur mutant of Neisseria gonorrhoeae.
The pathogenic Neisseria spp. produce a number of iron-regulated gene products that are thought to be important in virulence. Iron-responsive regulation of these gene products has been attributed to...
Interruption of the gpxA gene increases the sensitivity of Neisseria meningitidis to paraquat.
Antioxidant enzymes are thought to be important for the survival of pathogenic Neisseria species. We have further characterized the glutathione peroxidase homolog gene (gpxA), which we recently...
A penicillin-resistant (Penr) non-penicillinase-producing Neisseria gonorrhoeae strain responsible for an outbreak affecting 199 persons in Durham, N.C., in 1983 was studied to determine the genetic...
Cohen, M S, Cooney, M H, Blackman, E, Sparling, P F
The in vitro susceptibility of penicillinase-producing and intrinsically resistant Neisseria gonorrhoeae strains to 13 antimicrobial agents was tested. Regardless of the type of resistance, these...
Shafer, W M, Guymon, L F, Lind, I, Sparling, P F
A mutation (env-10) conferring increased susceptibility to drugs, dyes, and detergents was detected in a clinical isolate of Neisseria gonorrhoeae. In certain strains, env-10 also affected...
Neisseria meningitidis produces iron-regulated proteins related to the RTX family of exoproteins.
Thompson, S A, Wang, L L, West, A, Sparling, P F
A monoclonal antibody (A4.85) which reacted with Fe-regulated proteins of Neisseria meningitidis, was used to isolate a lambda gt11 clone from N. meningitidis FAM20. Chromosomal fragments flanking...
Cornelissen, C N, Biswas, G D, Sparling, P F
The gene for gonococcal transferrin-binding protein 1 (TBP1) was cloned behind an inducible promoter in Escherichia coli. The resultant strain was capable of binding human transferrin with the same...
Anderson, J E, Sparling, P F, Cornelissen, C N
Pathogenic Neisseria species have been shown to scavenge iron from transferrin (Tf), although the mechanism is not yet fully understood. Two iron-repressible proteins that exhibit Tf-binding activity...
Cornelissen, C N, Biswas, G D, Tsai, J, Paruchuri, D K, Thompson, S A, Sparling, P F
The pathogenic Neisseria species are capable of utilizing transferrin as their sole source of iron. A neisserial transferrin receptor has been identified and its characteristics defined; however, the...
Species-specific uptake of DNA by gonococci is mediated by a 10-base-pair sequence.
Elkins, C, Thomas, C E, Seifert, H S, Sparling, P F
Piliated Neisseria gonorrhoeae are known to be transformed less readily if transforming DNA competes with DNA containing the 10-bp sequence GCCGTCTGAA. It has been postulated that the 10-bp sequence...
Transformation-deficient mutants of piliated Neisseria gonorrhoeae.
Biswas, G D, Lacks, S A, Sparling, P F
Seven transformation-deficient mutants of piliated, competent Neisseria gonorrhoeae were isolated by screening them for their inability to be transformed by chromosomal DNA after chemical...
Aerobactin, a dihydroxamate siderophore produced by many strains of enteric bacteria, stimulated the growth of Neisseria gonorrhoeae FA19 and F62 in iron-limiting medium. However, gonococci did not...
Biswas, G D, Graves, J, Schwalbe, R, Sparling, P F
A 4.2-kilobase (kb) cryptic plasmid is present in 96% of isolates of Neisseria gonorrhoeae. An inability to construct isogenic derivatives which vary in the presence of the 4.2-kb plasmid has...
Blanton, K J, Biswas, G D, Tsai, J, Adams, J, Dyer, D W, Davis, S M, ...
Transferrin (TF) and lactoferrin (LF) are probably the major sources of iron (Fe) for Neisseria gonorrhoeae in vivo. We isolated mutants of N. gonorrhoeae FA19 that were unable to grow with Fe bound...
Linearization of donor DNA during plasmid transformation in Neisseria gonorrhoeae.
Biswas, G D, Burnstein, K L, Sparling, P F
We examined the fate of plasmid DNA after uptake during transformation in Neisseria gonorrhoeae. An 11.5-kilobase plasmid, pFA10, was processed to linear double-stranded DNA during uptake by...
Entry of double-stranded deoxyribonucleic acid during transformation of Neisseria gonorrhoeae.
The state of donor deoxyribonucleic acid after entry into competent cells was examined by assaying the transformed cell lysates for donor-marker transforming activity and density of donor...
Cell envelope alterations in antibiotic-sensitive and-resistant strains of Neisseria gonorrhoeae.
Guymon, L F, Walstad, D L, Sparling, P F
The cell envelopes of antibiotic-resistant and -sensitive isogenic strains of Neisseria gonorrhoeae were analyzed to determine whether acquisition of genetic loci for altered antibiotic sensitivity...
Biswas, G D, Graves, J F, Sox, T E, Tenover, F C, Sparling, P F
A 42-kilobase hybrid Pcr plasmid (pFA14) was formed when the naturally occurring 7.2-kilobase Pcr plasmid pFA3 was introduced by transformation into a competent gonococcal recipient containing the...
Sequence-specific DNA uptake in transformation of Neisseria gonorrhoeae.
Graves, J F, Biswas, G D, Sparling, P F
Piliated, competent gonococci are known to preferentially take up homologous transforming DNA into the cell. We examined the mechanism for DNA uptake with pFA10, a hybrid 11.5-kilobase (kb)...
Conjugative plasmids in Neisseria gonorrhoeae.
Sox, T E, Mohammed, W, Blackman, E, Biswas, G, Sparling, P F
A conjugation system initially discovered in beta-lactamase-producing gonococci mobilized small non-selftransmissible R plasmids encoding beta-lactamase (penicillinase) production into other...
Factors affecting genetic transformation of Neisseria gonorrhoeae.
Biswas, G D, Sox, T, Blackman, E, Sparling, P F
Piliated gonococci were competent in genetic transformation in all stages of growth in minimal and enriched media, but nonpiliated cells were almost totally incompetent. Uptake of deoxyribonucleic...
Altered outer membrane protein in different colonial types of Neisseria gonorrhoeae.
Walstad, D L, Guymon, L F, Sparling, P F
Dark-colored colony types of Neisseria gonorrhoeae (T3 and dark variants of T1 and T2) had markedly increased amounts of an approximately 28,000-dalton outer membrane protein, as compared with...
Sparling, P F, Sarubbi, F A, Blackman, E
The genetics of low-level resistance to penicillin and other antibiotics in a clinical isolate and a multistep laboratory mutant of Neisseria gonorrhoea was studied by transformation. Mutations at...
Loss of low-level antibiotic resistance in Neisseria gonorrhoeae due to env mutations.
Sarubbi, F A, Sparling, P F, Blackman, E, Lewis, E
Mutations (env) which resulted in increased sensitivity of gonococci to diverse compounds were studied by transformation. Strains carrying an env mutation were more sensitive than wild-type strains...
Wild-type, antibiotic-resistant and hypersensitive isogenic strains of Neisseria gonorrhoeae were studied for uptake of crystal violet, rates of autolysis, and response to lysozyme. Total uptake of...
Chromosomal location of antibiotic resistance genes in Neisseria gonorrhoeae.
Biswas, G, Comer, S, Sparling, P F
Transformation with purified plasmid and chromosomal deoxyribonucleic acid from a clinical isolate of Neisseria gonorrhoeae showed that each of seven loci affecting drug resistance (penA, penB, ery,...
Iron uptake from lactoferrin and transferrin by Neisseria gonorrhoeae.
McKenna, W R, Mickelsen, P A, Sparling, P F, Dyer, D W
The major iron (Fe) sources available to Neisseria gonorrhoeae in the human host are probably transferrin (TF) and lactoferrin (LF). Although a number of studies have examined Fe uptake by Neisseria...
Dyer, D W, West, E P, McKenna, W, Thompson, S A, Sparling, P F
We isolated an iron-uptake mutant of Neisseria meningitidis M986-NCV-1 that was severely limited in the ability to use several sources of iron in the form of Fe3+. This mutant, FAM11, grew poorly or...
Tsai, J, Dyer, D W, Sparling, P F
Although Neisseria meningitidis does not produce siderophores, it is able to obtain iron from human transferrin. We observed saturable specific binding of 125I-labeled human transferrin to...
Human immune response to iron-repressible outer membrane proteins of Neisseria meningitidis.
Black, J R, Dyer, D W, Thompson, M K, Sparling, P F
Neisseria meningitidis grown under iron-limiting conditions in vitro expresses additional iron-repressible outer membrane proteins (FeRPs). To see which FeRPs were expressed and immunogenic in human...
Effects of serum carrier proteins on the growth of pathogenic neisseriae with heme-bound iron.
Dyer, D W, West, E P, Sparling, P F
The pathogenic neisseriae can use free heme and hemoglobin as an essential source of iron (Fe) for growth in vitro, but it is unknown whether they can utilize heme bound to human hemopexin or to...
Danielsson, D, Faruki, H, Dyer, D, Sparling, P F
In gonococci, the nonspecific antimicrobial resistance locus penB is known to be closely linked to loci designated nmp that alter the Mr and antigenicity of the outer membrane porin protein I (P.I)....
Haemophilus influenzae can use human transferrin as a sole source for required iron.
Herrington, D A, Sparling, P F
Haemophilus influenzae grown on enriched medium containing protoporphyrin IX rather than hemin was iron starved by the addition of the chelator ethylenediamine di-o-hydroxyphenylacetic acid. Iron...
Schwalbe, R S, Sparling, P F, Cannon, J G
Gonococci isolated from localized urogenital infections usually possess one or more protein II (P.II) species in the outer membrane, but the structural and antigenic variation of these proteins among...
For acquisition of iron, an essential nutrient, most microorganisms produce siderophores (low-molecular-weight iron-chelating compounds) and membrane proteins to serve as receptors for the...
Cannon, J G, Buchanan, T M, Sparling, P F
Previous work indicates that strains of Neisseria gonorrhoeae isolated in Seattle, Wash., and Atlanta, Ga., show an association between serotypes 1 and 2 of protein I of the outer membrane and the...
Neisseria meningitidis produces proteins (FrpA and FrpC) related to the RTX cytotoxin family. In meningococcal strain FAM20 these proteins were both localized in the outer membrane and secreted into...
Genetics of protein I of Neisseria gonorrhoeae: construction of hybrid porins.
Carbonetti, N H, Simnad, V I, Seifert, H S, So, M, Sparling, P F
Protein I (PI), the major outer membrane protein of Neisseria gonorrhoeae, is a porin and occurs in two major immunochemical classes, A and B. By using shuttle mutagenesis to insert a selectable...
Genetic locus (nmp-1) affecting the principal outer membrane protein of Neisseria gonorrhoeae.
Cannon, J G, Klapper, D G, Blackman, E Y, Sparling, P F
An increase in the apparent molecular weight of the principal outer membrane protein (POMP) of Neisseria gonorrhoeae is associated with introduction of the penB2 genetic marker, which results in...
High-frequency conjugal transfer of a gonococcal penicillinase plasmid.
Biswas, G D, Blackman, E Y, Sparling, P F
Gonococci containing a 24 X 10(6)-dalton conjugal plasmid were able to mobilize for transfer a smaller, non-self-transmissible penicillinase (Pcr) plasmid with high frequency under appropriate...
Carbonetti, N H, Sparling, P F
Protein I (P.I) is the major outer membrane protein of Neisseria gonorrhoeae and serves as a porin. By using oligonucleotide probes derived from the known amino-terminal sequence of the mature...
The ability of Neisseria species to use iron compounds and to compete with iron-binding proteins was examined with deferrated defined medium and the iron chelator deferoxamine. All Neisseria species...
Shafer, W M, Guymon, L F, Sparling, P F
A previously undescribed genetic site (sac-3) affecting susceptibility of the gonococcus to normal human serum was localized on the gonococcal chromosome. The presence of the sac-3+ allele in a...
Daly, J A, Lee, T J, Spitznagel, J K, Sparling, P F
Gonococci which cause disseminated gonococcal infection are nearly always highly penicillin sensitive, in contrast to many isolates causing uncomplicated gonorrhea. We questioned whether any of the...
Mickelsen, P A, Blackman, E, Sparling, P F
The ability of 107 Neisseria isolates to compete for iron with human lactoferrin (LF) was examined. Each of 15 meningococci, 53% of 59 selected gonococci, and 24% of 33 commensal Neisseria could use...
Eisenstein, B I, Lee, T J, Sparling, P F
We have determined that isolates of Neisseria gonorrhoeae from patients with disseminated gonococcal infection (DGI) are different from randomly collected isolates from patients with uncomplicated...
Transformation-derived Neisseria gonorrhoeae plasmids with altered structure and function.
Sox, T E, Mohammed, W, Sparling, P F
Plasmid deoxyribonucleic acid from Neisseria gonorrhoeae containing a 7.1-kilobase (kb) (4.7-megadalton) penicillinase (Pcr) plasmid transformed homogenic gonococci to penicillinase production at a...
Vaccines for bacterial sexually transmitted infections: a realistic goal?
Sparling, P F, Elkins, C, Wyrick, P B, Cohen, M S
Bacterial infections of the genital tract (gonorrhea, chlamydia, chancroid, syphilis) are common and cause significant morbidity. Their importance is heightened by recent appreciation of their roles...
Turner, Paul C., Thomas, Christopher E., Elkins, Christopher, Clary, Susan, Sparling, P. F.
Many bacterial pathogens, including pathogenic neisseriae, can use heme as an iron source for growth. To study heme utilization by Neisseria gonorrhoeae, two heme biosynthetic mutants were...
Antioxidant enzymes are thought to be important for the survival of pathogenic Neisseria species. We isolated a glutathione peroxidase-related gene (gpxA) from Neisseria meningitidis FAM20. The N....
Characterization of lbpA, the structural gene for a lactoferrin receptor in Neisseria gonorrhoeae.
Neisseria gonorrhoeae acquires iron (Fe) efficiently from lactoferrin (LF). A 103-kDa gonococcal outer membrane LF-binding protein (Lbp) was identified previously. We isolated the structural gene...
Aebi, C, Stone, B, Beucher, M, Cope, L D, Maciver, I, Thomas, S E, ...
The amino acid sequence of the cell-surface-exposed, 81-kDa CopB outer membrane protein of Moraxella catarrhalis was found to be similar to those of TonB-dependent outer membrane proteins of other...
Chen, C J, Sparling, P F, Lewis, L A, Dyer, D W, Elkins, C
The majority of in vitro-grown Neisseria gonorrhoeae strains were unable to use hemoglobin as the sole source of iron for growth (Hgb-), but a minor population was able to do so (Hgb+). The ability...
Cohen, M S, Chai, Y, Britigan, B E, McKenna, W, Adams, J, Svendsen, T, ...
The quinone antibiotic streptonigrin is believed to kill bacteria by promoting formation of oxygen radicals. This antibiotic has also been used to select resistant bacterial mutants, some of which...
Cornelissen, C N, Anderson, J E, Sparling, P F
The molecular weight heterogeneities of Tbp1 and Tbp2 among a panel of 45 gonococcal isolates were assessed. The tbpB genes from four of these strains were sequenced to characterize the Tbp2 sequence...
FrpB (for Fe-regulated protein B) is a 76-kDa outer membrane protein that is part of the iron regulon of Neisseria gonorrhoeae and Neisseria meningitidis. The frpB gene from gonococcal strain FA19...
Cornelissen, C N, Sparling, P F
Neisseria gonorrhoeae is capable of iron utilization from human transferrin in a receptor-mediated event. Transferrin-binding protein 1 (Tbp1) and Tbp2 have been implicated in transferrin receptor...
Isolation and analysis of a fur mutant of Neisseria gonorrhoeae.
The pathogenic Neisseria spp. produce a number of iron-regulated gene products that are thought to be important in virulence. Iron-responsive regulation of these gene products has been attributed to...
Interruption of the gpxA gene increases the sensitivity of Neisseria meningitidis to paraquat.
Antioxidant enzymes are thought to be important for the survival of pathogenic Neisseria species. We have further characterized the glutathione peroxidase homolog gene (gpxA), which we recently...
A penicillin-resistant (Penr) non-penicillinase-producing Neisseria gonorrhoeae strain responsible for an outbreak affecting 199 persons in Durham, N.C., in 1983 was studied to determine the genetic...
Cohen, M S, Cooney, M H, Blackman, E, Sparling, P F
The in vitro susceptibility of penicillinase-producing and intrinsically resistant Neisseria gonorrhoeae strains to 13 antimicrobial agents was tested. Regardless of the type of resistance, these...
Shafer, W M, Guymon, L F, Lind, I, Sparling, P F
A mutation (env-10) conferring increased susceptibility to drugs, dyes, and detergents was detected in a clinical isolate of Neisseria gonorrhoeae. In certain strains, env-10 also affected...
Neisseria meningitidis produces iron-regulated proteins related to the RTX family of exoproteins.
Thompson, S A, Wang, L L, West, A, Sparling, P F
A monoclonal antibody (A4.85) which reacted with Fe-regulated proteins of Neisseria meningitidis, was used to isolate a lambda gt11 clone from N. meningitidis FAM20. Chromosomal fragments flanking...
Cornelissen, C N, Biswas, G D, Sparling, P F
The gene for gonococcal transferrin-binding protein 1 (TBP1) was cloned behind an inducible promoter in Escherichia coli. The resultant strain was capable of binding human transferrin with the same...
Anderson, J E, Sparling, P F, Cornelissen, C N
Pathogenic Neisseria species have been shown to scavenge iron from transferrin (Tf), although the mechanism is not yet fully understood. Two iron-repressible proteins that exhibit Tf-binding activity...
Cornelissen, C N, Biswas, G D, Tsai, J, Paruchuri, D K, Thompson, S A, Sparling, P F
The pathogenic Neisseria species are capable of utilizing transferrin as their sole source of iron. A neisserial transferrin receptor has been identified and its characteristics defined; however, the...
Species-specific uptake of DNA by gonococci is mediated by a 10-base-pair sequence.
Elkins, C, Thomas, C E, Seifert, H S, Sparling, P F
Piliated Neisseria gonorrhoeae are known to be transformed less readily if transforming DNA competes with DNA containing the 10-bp sequence GCCGTCTGAA. It has been postulated that the 10-bp sequence...
Transformation-deficient mutants of piliated Neisseria gonorrhoeae.
Biswas, G D, Lacks, S A, Sparling, P F
Seven transformation-deficient mutants of piliated, competent Neisseria gonorrhoeae were isolated by screening them for their inability to be transformed by chromosomal DNA after chemical...
Aerobactin, a dihydroxamate siderophore produced by many strains of enteric bacteria, stimulated the growth of Neisseria gonorrhoeae FA19 and F62 in iron-limiting medium. However, gonococci did not...
Biswas, G D, Graves, J, Schwalbe, R, Sparling, P F
A 4.2-kilobase (kb) cryptic plasmid is present in 96% of isolates of Neisseria gonorrhoeae. An inability to construct isogenic derivatives which vary in the presence of the 4.2-kb plasmid has...
Blanton, K J, Biswas, G D, Tsai, J, Adams, J, Dyer, D W, Davis, S M, ...
Transferrin (TF) and lactoferrin (LF) are probably the major sources of iron (Fe) for Neisseria gonorrhoeae in vivo. We isolated mutants of N. gonorrhoeae FA19 that were unable to grow with Fe bound...
Linearization of donor DNA during plasmid transformation in Neisseria gonorrhoeae.
Biswas, G D, Burnstein, K L, Sparling, P F
We examined the fate of plasmid DNA after uptake during transformation in Neisseria gonorrhoeae. An 11.5-kilobase plasmid, pFA10, was processed to linear double-stranded DNA during uptake by...
Entry of double-stranded deoxyribonucleic acid during transformation of Neisseria gonorrhoeae.
The state of donor deoxyribonucleic acid after entry into competent cells was examined by assaying the transformed cell lysates for donor-marker transforming activity and density of donor...
Transformation-derived Neisseria gonorrhoeae plasmids with altered structure and function.
Sox, T E, Mohammed, W, Sparling, P F
Plasmid deoxyribonucleic acid from Neisseria gonorrhoeae containing a 7.1-kilobase (kb) (4.7-megadalton) penicillinase (Pcr) plasmid transformed homogenic gonococci to penicillinase production at a...
Cell envelope alterations in antibiotic-sensitive and-resistant strains of Neisseria gonorrhoeae.
Guymon, L F, Walstad, D L, Sparling, P F
The cell envelopes of antibiotic-resistant and -sensitive isogenic strains of Neisseria gonorrhoeae were analyzed to determine whether acquisition of genetic loci for altered antibiotic sensitivity...
Biswas, G D, Graves, J F, Sox, T E, Tenover, F C, Sparling, P F
A 42-kilobase hybrid Pcr plasmid (pFA14) was formed when the naturally occurring 7.2-kilobase Pcr plasmid pFA3 was introduced by transformation into a competent gonococcal recipient containing the...
Sequence-specific DNA uptake in transformation of Neisseria gonorrhoeae.
Graves, J F, Biswas, G D, Sparling, P F
Piliated, competent gonococci are known to preferentially take up homologous transforming DNA into the cell. We examined the mechanism for DNA uptake with pFA10, a hybrid 11.5-kilobase (kb)...
Conjugative plasmids in Neisseria gonorrhoeae.
Sox, T E, Mohammed, W, Blackman, E, Biswas, G, Sparling, P F
A conjugation system initially discovered in beta-lactamase-producing gonococci mobilized small non-selftransmissible R plasmids encoding beta-lactamase (penicillinase) production into other...
Factors affecting genetic transformation of Neisseria gonorrhoeae.
Biswas, G D, Sox, T, Blackman, E, Sparling, P F
Piliated gonococci were competent in genetic transformation in all stages of growth in minimal and enriched media, but nonpiliated cells were almost totally incompetent. Uptake of deoxyribonucleic...
Altered outer membrane protein in different colonial types of Neisseria gonorrhoeae.
Walstad, D L, Guymon, L F, Sparling, P F
Dark-colored colony types of Neisseria gonorrhoeae (T3 and dark variants of T1 and T2) had markedly increased amounts of an approximately 28,000-dalton outer membrane protein, as compared with...
Sparling, P F, Sarubbi, F A, Blackman, E
The genetics of low-level resistance to penicillin and other antibiotics in a clinical isolate and a multistep laboratory mutant of Neisseria gonorrhoea was studied by transformation. Mutations at...
Loss of low-level antibiotic resistance in Neisseria gonorrhoeae due to env mutations.
Sarubbi, F A, Sparling, P F, Blackman, E, Lewis, E
Mutations (env) which resulted in increased sensitivity of gonococci to diverse compounds were studied by transformation. Strains carrying an env mutation were more sensitive than wild-type strains...
Wild-type, antibiotic-resistant and hypersensitive isogenic strains of Neisseria gonorrhoeae were studied for uptake of crystal violet, rates of autolysis, and response to lysozyme. Total uptake of...
Chromosomal location of antibiotic resistance genes in Neisseria gonorrhoeae.
Biswas, G, Comer, S, Sparling, P F
Transformation with purified plasmid and chromosomal deoxyribonucleic acid from a clinical isolate of Neisseria gonorrhoeae showed that each of seven loci affecting drug resistance (penA, penB, ery,...
Iron uptake from lactoferrin and transferrin by Neisseria gonorrhoeae.
McKenna, W R, Mickelsen, P A, Sparling, P F, Dyer, D W
The major iron (Fe) sources available to Neisseria gonorrhoeae in the human host are probably transferrin (TF) and lactoferrin (LF). Although a number of studies have examined Fe uptake by Neisseria...
Dyer, D W, West, E P, McKenna, W, Thompson, S A, Sparling, P F
We isolated an iron-uptake mutant of Neisseria meningitidis M986-NCV-1 that was severely limited in the ability to use several sources of iron in the form of Fe3+. This mutant, FAM11, grew poorly or...
Tsai, J, Dyer, D W, Sparling, P F
Although Neisseria meningitidis does not produce siderophores, it is able to obtain iron from human transferrin. We observed saturable specific binding of 125I-labeled human transferrin to...
Human immune response to iron-repressible outer membrane proteins of Neisseria meningitidis.
Black, J R, Dyer, D W, Thompson, M K, Sparling, P F
Neisseria meningitidis grown under iron-limiting conditions in vitro expresses additional iron-repressible outer membrane proteins (FeRPs). To see which FeRPs were expressed and immunogenic in human...
Effects of serum carrier proteins on the growth of pathogenic neisseriae with heme-bound iron.
Dyer, D W, West, E P, Sparling, P F
The pathogenic neisseriae can use free heme and hemoglobin as an essential source of iron (Fe) for growth in vitro, but it is unknown whether they can utilize heme bound to human hemopexin or to...
Danielsson, D, Faruki, H, Dyer, D, Sparling, P F
In gonococci, the nonspecific antimicrobial resistance locus penB is known to be closely linked to loci designated nmp that alter the Mr and antigenicity of the outer membrane porin protein I (P.I)....
Haemophilus influenzae can use human transferrin as a sole source for required iron.
Herrington, D A, Sparling, P F
Haemophilus influenzae grown on enriched medium containing protoporphyrin IX rather than hemin was iron starved by the addition of the chelator ethylenediamine di-o-hydroxyphenylacetic acid. Iron...
Schwalbe, R S, Sparling, P F, Cannon, J G
Gonococci isolated from localized urogenital infections usually possess one or more protein II (P.II) species in the outer membrane, but the structural and antigenic variation of these proteins among...
For acquisition of iron, an essential nutrient, most microorganisms produce siderophores (low-molecular-weight iron-chelating compounds) and membrane proteins to serve as receptors for the...
Cannon, J G, Buchanan, T M, Sparling, P F
Previous work indicates that strains of Neisseria gonorrhoeae isolated in Seattle, Wash., and Atlanta, Ga., show an association between serotypes 1 and 2 of protein I of the outer membrane and the...
Neisseria meningitidis produces proteins (FrpA and FrpC) related to the RTX cytotoxin family. In meningococcal strain FAM20 these proteins were both localized in the outer membrane and secreted into...
Genetics of protein I of Neisseria gonorrhoeae: construction of hybrid porins.
Carbonetti, N H, Simnad, V I, Seifert, H S, So, M, Sparling, P F
Protein I (PI), the major outer membrane protein of Neisseria gonorrhoeae, is a porin and occurs in two major immunochemical classes, A and B. By using shuttle mutagenesis to insert a selectable...
Genetic locus (nmp-1) affecting the principal outer membrane protein of Neisseria gonorrhoeae.
Cannon, J G, Klapper, D G, Blackman, E Y, Sparling, P F
An increase in the apparent molecular weight of the principal outer membrane protein (POMP) of Neisseria gonorrhoeae is associated with introduction of the penB2 genetic marker, which results in...
High-frequency conjugal transfer of a gonococcal penicillinase plasmid.
Biswas, G D, Blackman, E Y, Sparling, P F
Gonococci containing a 24 X 10(6)-dalton conjugal plasmid were able to mobilize for transfer a smaller, non-self-transmissible penicillinase (Pcr) plasmid with high frequency under appropriate...
Carbonetti, N H, Sparling, P F
Protein I (P.I) is the major outer membrane protein of Neisseria gonorrhoeae and serves as a porin. By using oligonucleotide probes derived from the known amino-terminal sequence of the mature...
The ability of Neisseria species to use iron compounds and to compete with iron-binding proteins was examined with deferrated defined medium and the iron chelator deferoxamine. All Neisseria species...
Shafer, W M, Guymon, L F, Sparling, P F
A previously undescribed genetic site (sac-3) affecting susceptibility of the gonococcus to normal human serum was localized on the gonococcal chromosome. The presence of the sac-3+ allele in a...
Daly, J A, Lee, T J, Spitznagel, J K, Sparling, P F
Gonococci which cause disseminated gonococcal infection are nearly always highly penicillin sensitive, in contrast to many isolates causing uncomplicated gonorrhea. We questioned whether any of the...
Mickelsen, P A, Blackman, E, Sparling, P F
The ability of 107 Neisseria isolates to compete for iron with human lactoferrin (LF) was examined. Each of 15 meningococci, 53% of 59 selected gonococci, and 24% of 33 commensal Neisseria could use...
Eisenstein, B I, Lee, T J, Sparling, P F
We have determined that isolates of Neisseria gonorrhoeae from patients with disseminated gonococcal infection (DGI) are different from randomly collected isolates from patients with uncomplicated...
The roles of sexual and asexual gene transfer in emergence of antibiotic resistant gonococci.
Antibiotic resistance is an increasing problem among gonococci, not only in Asia, Africa and other regions, but also in the U.S.A. Resistance is of two fundamental types: plasmid-mediated, due to...