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Papers by Stephen Morse
Journal of Clinical Microbiology, 1976
A suspending medium was developed for use with the Minitek system for the confirmatory identifica... more A suspending medium was developed for use with the Minitek system for the confirmatory identification of Neisseria gonorrhoeae, N. meningitidis, and N. lactamica based upon the production of acid from various carbohydrates. The addition of sodium bicarbonate to the medium made negative reactions easier to read. More isolates of N. gonorrhoeae were identified with the suspending medium in the Minitek system than with cystine-Trypticase agar media. With a suitable inoculum size, a positive identification could be made in less than 1 h; most isolates (90,8%) could be identified within 4 h of inoculation. The Minitek system is reliable and easy to use.
Infection and Immunity, 1973
Several factors which regulate the synthesis of enterotoxin B were examined in Staphylococcus aur... more Several factors which regulate the synthesis of enterotoxin B were examined in Staphylococcus aureus S-6 and in its heme-requiring mutant S-6H2. The kinetics of enterotoxin B synthesis during anaerobic growth were identical to those observed under aerobic conditions; extracellular enterotoxin accumulated in the medium during the transition between exponential and stationary phase growth. Strain S-6H2 lacked a functional electron transport system unless the medium was supplemented with heme. In a casein hydrolysate medium, the presence or absence of a functional electron transport system had no effect upon the differential rate of toxin synthesis. The repression of toxin synthesis by glucose at either pH 6.0 or 7.7 or by pyruvate at pH 7.7 occurred in the absence of a functional electron transport system, but was enhanced significantly in its presence. Thus, a functional electron transport system appears to be involved in regulating the degree of glucose and pyruvate repression of en...
Infection and Immunity, 1978
This study examined the effect of pH on the metabolism of glucose by Neisseria gonorrhoeae. Radio... more This study examined the effect of pH on the metabolism of glucose by Neisseria gonorrhoeae. Radiorespirometric studies revealed that cells growing at pH 7.2 or 8.0 metabolized glucose primarily (ca. 80%) via the Entner-Doudoroff pathway. The remainder of the glucose was metabolized via the pentose phosphate pathway (ca. 20%). The tricarboxylic acid cycle was not active during glucose catabolism at either pH 7.2 or 8.0, and acetate accumulated in the medium. Cells growing at pH 6.0 had markedly increased pentose phosphate pathway activity (ca. 50%) and a functioning tricarboxylic acid cycle. The alteration in pathways was not due to differences in growth rate, but to the pH of the medium. Chemical fractionation of labeled cells and total hexose analyses revealed that growth pH markedly affected the composition of the gonococcus.
Infection and Immunity, 1993
The promoter region of the major iron-regulated protein of Neisseria gonorrhoeae, Fbp, has two re... more The promoter region of the major iron-regulated protein of Neisseria gonorrhoeae, Fbp, has two regions that exhibit homology with the Escherichia coli consensus Fur-binding sequences. Gel retardation assays suggested that purified E. coli Fur bound to two sites within the Fbp promoter. The presence of a gonococcal Fur homolog was suggested by Southern hybridization under conditions of low stringency, which revealed a DNA locus that exhibited homology to the E. coli fur gene. Oligonucleotides derived from the conserved regions of fur genes of extremely diverse bacteria were used to amplify a 140-bp fragment of a putative gonococcal fur gene. This fragment was used to identify clones containing the entire gonococcal fur gene. After sequencing the gonococcal fur gene and its promoter region, we found that gonococcal Fur exhibited 50% identity with E. coli Fur at the amino acid level; however, it complemented two E. coli Fur- mutants. The presence of a Fur homolog in N. gonorrhoeae sugg...
Infection and Immunity, 1977
The addition of 10 microgram of penicillin G per ml to log-phase cultures of Neisseria gonorrhoea... more The addition of 10 microgram of penicillin G per ml to log-phase cultures of Neisseria gonorrhoeae JW-31 (minimum inhibitory concentration for penicillin G, less than 0.007 microgram/ml) resulted in cellular lysis after a lag of 30 min. Penicillin markedly decreased the rate of peptidoglycan synthesis and enhanced the rate of hydrolysis of existing peptidoglycan. Hydrolysis was initiated immediately after addition of penicillin; cellular lysis did not occur until a considerable percentage of the peptidoglycan had been degraded. Cellular lysis was not due to penicillin per se but resulted from inhibition of cell wall synthesis. When cells were grown in media buffered with N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid at pH 6, penicillin did not cause lysis; however, at this pH, peptidoglycan hydrolysis occurred and cells lost viability at the same rate as in the control (pH 7.2). We suggest that the stability of gonococci grown at pH 6 is related to increased stability of ...
Journal of Bacteriology, 1974
The metabolism of glucose was examined in several clinical isolates of Neisseria gonorrhoeae . Ra... more The metabolism of glucose was examined in several clinical isolates of Neisseria gonorrhoeae . Radiorespirometric studies revealed that growing cells metabolized glucose by a combination on the Entner-Doudoroff and pentose phosphate pathways. A portion of the glyceraldehyde-3-phosphate formed via the Entner-Doudoroff pathway was recycled by conversion to glucose-6-phosphate. Subsequent catabolism of this glucose-6-phosphate by either the Entner-Doudoroff or pentose phosphate pathways yielded CO 2 from the original C6 of glucose. Enzyme analyses confirmed the presence of all enzymes of the Entner-Doudoroff, pentose phosphate, and Embden-Meyerhof-Parnas pathways. There was always a high specific activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) relative to that of 6-phosphogluconate dehydrogenase (EC 1.1.1.44). The glucose-6-phosphate dehydrogenase utilized either nicotinamide adenine dinucleotide phosphate or nicotinamide adenine dinucleotide as electron acceptor. Acetate w...
Journal of Bacteriology, 1981
Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas a... more Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas aeruginosa PA103, and isogenic resistant variants were isolated. The interaction of pyocin-sensitive and isogenic pyocin-resistant strains with wheat germ agglutinin (WGA) agglutinated all pyocin-sensitive, but not pyocin-resistant, strains. Binding of WGA to three pyocin-sensitive strains and their isogenic pyocin-resistant variants was examined quantitatively by using fluorescein-conjugated lectin. Pyocin-resistant strains maximally bound one-third to one-eighth the quantity of WGA bound by isogenic-sensitive strains. Linear Scatchard plots revealed homogeneous WGA-binding sites on three pyocin-sensitive and one pyocin-resistant strains. Biphasic Scatchard plots, obtained with two pyocin-resistant strains, show that WGA-binding sites in these strains are heterogeneous. The number of WGA-binding sites for pyocin-sensitive organisms ranged from 8 x 10(5) to 1 x 10(6) sites per coccus and ...
Infection and Immunity, 1977
Fatty acids of various chain lengths (C 1 to C 24 ) were examined for their effects on growth, ox... more Fatty acids of various chain lengths (C 1 to C 24 ) were examined for their effects on growth, oxygen consumption, and in vitro reduced nicotinamide adenine dinucleotide oxidase activity of Neisseria gonorrhoeae CS-7. The growth inhibition caused by saturated fatty acids increased with increasing chain length to a maximum with palmitic acid (C 16 ). Stearic acid (C 18 ) and longer saturated fatty acids showed little inhibition of growth. However, unsaturated fatty acids of chain length C 16 to C 20 were inhibitory. Similar inhibition was observed with Bacillus subtilis and a deep rough mutant of Salmonella typhimurium. Wildtype S. typhimurium and Pseudomonas aeruginosa were more resistant to medium-chain (C 7 to C 10 ) fatty acids and completely resistant to long-chain (C 12 to C 18 ) fatty acids. Thus, sensitivity of N. gonorrhoeae to long-chain fatty acids appears to be related to the permeability of the outer membrane. Growth inhibition by short-chain (C 1 to C 6 ) fatty acids wa...
Journal of Clinical Microbiology, 1983
Various factors affect the sensitivity of Neisseria gonorrhoeae to physiological levels of hydrop... more Various factors affect the sensitivity of Neisseria gonorrhoeae to physiological levels of hydrophobic molecules. A total of 98 N. gonorrhoeae strains from rectal, cervical, and urethral cultures of homosexual men and heterosexual men and women were examined for their sensitivities to fecal lipids. Isolates were characterized according to cell envelope phenotype, auxotype, and protein I serogroup. Although cell envelope phenotype was an important factor in the resistance of this organism to fecal lipids (Mtr phenotype greater than wild type greater than Env phenotype), other factors were also of importance. AHU- strains (strains having a requirement for arginine, hypoxanthine, and uracil) uniformly exhibited a wild-type envelope phenotype but were as sensitive to fecal lipids as were Env strains. The protein I serogroup was not a factor in determining the sensitivity of wild-type envelope phenotype non-AHU- strains to fecal lipids. However, sexual preference and site of isolation we...
Journal of Clinical Microbiology, 1981
Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity ... more Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity and enhancement of the coagglutination reaction of the Phadebact gonococcus test. These conditions included an alkaline pH (pH 8.3) and the presence of divalent cation chelators such as ethylenediaminetetraacetic acid or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. Heating cell suspensions at 90 degrees C for 15 min before assay by coagglutination produced a further increase in sensitivity and enhancement of the reaction. Gonococcal lipopolysaccharide was found to be an important antigen in these coagglutination reactions. The detection of lipopolysaccharide was markedly enhanced by the addition of chelating agents.
Journal of Bacteriology, 1997
In this study, we have mapped the promoter region of the Neisseria gonorrhoeae ferric iron bindin... more In this study, we have mapped the promoter region of the Neisseria gonorrhoeae ferric iron binding protein-encoding gene fbpA, determined the start point of transcription, and examined the accumulation of fbpA mRNA Primer extension analysis of the fbpA promoter region indicated a single transcriptional start site located 51 bp upstream of the ATG translational start site. Northern blot analysis with a 200-bp fbpA structural gene probe detected one transcript of 1.0 kb in RNAs extracted from gonococcal cultures grown under iron-restricted conditions; the 1.0-kb transcript was observed to accumulate at a steady rate throughout the growth cycle. In comparison, in cultures grown under iron-sufficient conditions, the intensity of the 1.0-kb transcript was reduced considerably. Isolation of total RNA from rifampin-treated cells indicated that the half-life of the 1.0-kb fbpA transcript in cells grown under iron-restricted conditions was 1.2 +/- 0.2 min, while that of the 1.0-kb fbpA trans...
Journal of Medical Microbiology, 1987
The production of toxic shock syndrome toxin-1 (TSST-1) was studied in batch and continuous cultu... more The production of toxic shock syndrome toxin-1 (TSST-1) was studied in batch and continuous culture of Staphylococcus aureus strain 1 169 in a carbohydratefree chemically defined medium (CDM). In continuous culture oxygen-and argininelimitation were required for steady-state TSST-1 synthesis. Aeration suppressed toxin synthesis. The amount of TSST-1 per mg dry weight (specific toxin) at dilution rates from 0.05 to 0.15 h-was inversely proportional to the dilution rate. Protease activity increased with increasing dilution rates. In batch culture, TSST-1 began to accumulate in the medium towards the end of the exponential phase of growth, after a critical cell mass was attained. Maximum specific toxin production was observed in medium with an initial pH between 6.5 and 7.0. Growth and toxin synthesis took place in anaerobic conditions when CDM was supplemented with pyruvate and uracil. The Mg++ concentration had no effect on the specific toxin in anaerobic conditions. In aerobic conditions, specific toxin increased c. 23-fold as the Mg + + concentrations increased to 0.4 mM. Further increases in the Mg+ + concentration resulted in a reduction in specific toxin.
Journal of Infectious Diseases, 1986
In 1984 and 1985, outbreaks of genital ulcers occurred in Florida and New York. Initial investiga... more In 1984 and 1985, outbreaks of genital ulcers occurred in Florida and New York. Initial investigations for syphilis, herpes simplex, Chlamydia trachomatis, and Haemophilus ducreyi did not implicate any of these organisms as etiologic agents. From the results of dot-immunobinding assays, we found that sera from the patients had higher levels of IgM (30 [47.6%] of 63 patients) and IgG (22 [34.9%] of 63 patients) reactivities with an outer-membrane preparation from H. ducreyi strain CIP542 than with outer-membrane preparations from Haemophilus influenzae ATCC 10211 or Haemophilus parainfluenzae ATCC 7901. In contrast, sera from 35 patients in the control group did not react with any of the outer-membrane preparations (P less than .01 for both IgM and and IgG reactivity), nor did sera from eight individuals with disease caused by H. influenzae (P = .051 for IgM reactivity, P = .02 for IgG reactivity). Indirect immunofluorescence assay using a monoclonal antibody reactive with outer-membrane preparations from H. ducreyi strain CIP542 stained organisms in smears of lesion material from genital ulcers from three of six patients. These results suggested that the cause of both outbreaks of genital ulcers was H. ducreyi which was subsequently isolated in both geographic areas.
Journal of Infectious Diseases, 1987
Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fi... more Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fimbriae by subcutaneous implantation. Depending upon monkey species, from eight to 20 implants could be established in each animal. Animals were given estrogen before percutaneous inoculation of the autografts with Chlamydia. Acute inflammatory changes were found in homografts examined in the first week after infection, with chronic inflammatory changes noted thereafter. Chlamydial inclusions were detected within fimbrial epithelial cells up to seven days postinoculation by fluorescent-antibody staining and immunoperoxidase staining with C. trachomatis-specific monoclonal antibody. Organisms were recovered from autografts up to five days after infection. Analysis of serum antibody by microimmunofluorescence revealed that serotype E-specific antibody of both IgM and IgG classes was produced after infection. We conclude that subcutaneously implanted fallopian tube autografts may provide a useful primate model for kinetic studies of chlamydial infection and immunity.
The Journal of Infectious Diseases, 1998
Antimicrobial Agents and Chemotherapy, 1980
All 11 clinically significant isolates of Branhamella catarrhalis examined in this study were fou... more All 11 clinically significant isolates of Branhamella catarrhalis examined in this study were found to produce f8-lactamase. The enzyme was apparently not plasmid associated since extrachromosomal deoxyribonucleic acid was not detected in any ofthe strains. The fi-lactamase activity of all strains was significantly depressed by the fi-lactamase inhibitors clavulanic acid and CP 45899. Based on comparisons of relative susceptibility to various ,B-lactam antibiotics, it was inferred that the ,B-lactamase of B. catarrhalis was significantly more active against penicillin congeners than against cephalosporin congeners. Most strains were not inhibited by readily achievable serum concentrations of the pencilhinasesensitive penicillins, penicillin G, ampicillin, and amoxicillin. Methicillin was equally ineffective. With rare exceptions, most strains of B. catarrhalis were inhibited by achievable serum concentrations of seven cephalosporins (cephalothin, cephapirin, cephaloridine, cephalexin, cephamandole, cefaclor, and cefuroxin) and one cephamycin (cefoxitin). All strains were uniformly resistant to clindamycin but were inhibited by achievable serum concentrations of erythromycin, tetracycline, chloramphenicol, and trimethoprimn-sulfamethoxazole. Comparison of geometric mean minimum inhibitory concentrations of all antimicrobial agents tested suggested that B. catarrhalis was most susceptible to cefoxitin, erythromycin, and tetracycline. Branhamella (Neisseria) catarrhalis, previously considered a harmless, upper respiratory tract commensal of humans (9), is now recognized as the etiological agent of significant disease in humans. It has been implicated in a wide variety of infectious processes (G.
Public health reports (Washington, D.C. : 1974)
Prehospital and Disaster Medicine, 2003
military in operational functions, and their spokesmen have taken part in broadcast interviews-bu... more military in operational functions, and their spokesmen have taken part in broadcast interviews-but purely at a factual operational level. The major issues still under review include: (1) Who is telling me? and (2) Can I trust them? Authorities must face the "fright factors" and "media triggers" and be ready in advance. But, there is a danger in having off-the-shelf, preprepared material that does not cover the precise details of a particular disruptive incident. Better to have generic material that can be adapted and prearranged conduits that can accept material at a few hours' notice.
Infection and Immunity, 1974
The effects of progesterone on the growth of pathogenic and nonpathogenic species of Neisseria we... more The effects of progesterone on the growth of pathogenic and nonpathogenic species of Neisseria were studied in liquid cultures. Only strains of N. gonorrhoeae and N. meningitidis were highly sensitive to growth inhibition by progesterone. This inhibitory effect was either bacteriostatic or bactericidal, depending upon the ratio of progesterone concentration to cell mass. The site of progesterone inhibition appeared to be located in the cell membrane; >86% of [4- 14 C]progesterone was recovered in the lipid-containing cell fractions. Membrane preparations from N. gonorrhoeae bound progesterone more efficiently than those from progesterone-insensitive cells. In addition, progesterone significantly inhibited the activity of the membrane-associated enzymes reduced nicotinamide adenine dinucleotide oxidase and (cytochrome b ) l -lactate dehydrogenase.
Infection and Immunity, 1986
Several iron-regulated proteins of Neisseria gonorrhoeae have been reported. One of these, a 37,0... more Several iron-regulated proteins of Neisseria gonorrhoeae have been reported. One of these, a 37,000-molecular-weight protein (37K protein), appears to be common to all gonococcal isolates. Recently, the occurrence of a similar protein has also been noted in N. meningitidis. The gonococcal 37K protein has been purified and used to produce both rabbit monospecific antiserum and murine monoclonal antibodies. Using these antibody reagents, we analyzed 57 strains from nine species of Neisseria and the closely related organism Branhamella catarrhalis for the presence of proteins antigenically related to the gonococcal 37K protein. Strains grown on medium with low iron content were probed for antigenic reactivity by Western blot techniques and an enzyme-linked immunosorbent assay. Proteins which cross-reacted with the rabbit monospecific antiserum were designated as AgR-37K proteins. The data indicated that the AgR-37K proteins were conserved among the 40 strains of N. gonorrhoeae, N. meni...
Journal of Clinical Microbiology, 1976
A suspending medium was developed for use with the Minitek system for the confirmatory identifica... more A suspending medium was developed for use with the Minitek system for the confirmatory identification of Neisseria gonorrhoeae, N. meningitidis, and N. lactamica based upon the production of acid from various carbohydrates. The addition of sodium bicarbonate to the medium made negative reactions easier to read. More isolates of N. gonorrhoeae were identified with the suspending medium in the Minitek system than with cystine-Trypticase agar media. With a suitable inoculum size, a positive identification could be made in less than 1 h; most isolates (90,8%) could be identified within 4 h of inoculation. The Minitek system is reliable and easy to use.
Infection and Immunity, 1973
Several factors which regulate the synthesis of enterotoxin B were examined in Staphylococcus aur... more Several factors which regulate the synthesis of enterotoxin B were examined in Staphylococcus aureus S-6 and in its heme-requiring mutant S-6H2. The kinetics of enterotoxin B synthesis during anaerobic growth were identical to those observed under aerobic conditions; extracellular enterotoxin accumulated in the medium during the transition between exponential and stationary phase growth. Strain S-6H2 lacked a functional electron transport system unless the medium was supplemented with heme. In a casein hydrolysate medium, the presence or absence of a functional electron transport system had no effect upon the differential rate of toxin synthesis. The repression of toxin synthesis by glucose at either pH 6.0 or 7.7 or by pyruvate at pH 7.7 occurred in the absence of a functional electron transport system, but was enhanced significantly in its presence. Thus, a functional electron transport system appears to be involved in regulating the degree of glucose and pyruvate repression of en...
Infection and Immunity, 1978
This study examined the effect of pH on the metabolism of glucose by Neisseria gonorrhoeae. Radio... more This study examined the effect of pH on the metabolism of glucose by Neisseria gonorrhoeae. Radiorespirometric studies revealed that cells growing at pH 7.2 or 8.0 metabolized glucose primarily (ca. 80%) via the Entner-Doudoroff pathway. The remainder of the glucose was metabolized via the pentose phosphate pathway (ca. 20%). The tricarboxylic acid cycle was not active during glucose catabolism at either pH 7.2 or 8.0, and acetate accumulated in the medium. Cells growing at pH 6.0 had markedly increased pentose phosphate pathway activity (ca. 50%) and a functioning tricarboxylic acid cycle. The alteration in pathways was not due to differences in growth rate, but to the pH of the medium. Chemical fractionation of labeled cells and total hexose analyses revealed that growth pH markedly affected the composition of the gonococcus.
Infection and Immunity, 1993
The promoter region of the major iron-regulated protein of Neisseria gonorrhoeae, Fbp, has two re... more The promoter region of the major iron-regulated protein of Neisseria gonorrhoeae, Fbp, has two regions that exhibit homology with the Escherichia coli consensus Fur-binding sequences. Gel retardation assays suggested that purified E. coli Fur bound to two sites within the Fbp promoter. The presence of a gonococcal Fur homolog was suggested by Southern hybridization under conditions of low stringency, which revealed a DNA locus that exhibited homology to the E. coli fur gene. Oligonucleotides derived from the conserved regions of fur genes of extremely diverse bacteria were used to amplify a 140-bp fragment of a putative gonococcal fur gene. This fragment was used to identify clones containing the entire gonococcal fur gene. After sequencing the gonococcal fur gene and its promoter region, we found that gonococcal Fur exhibited 50% identity with E. coli Fur at the amino acid level; however, it complemented two E. coli Fur- mutants. The presence of a Fur homolog in N. gonorrhoeae sugg...
Infection and Immunity, 1977
The addition of 10 microgram of penicillin G per ml to log-phase cultures of Neisseria gonorrhoea... more The addition of 10 microgram of penicillin G per ml to log-phase cultures of Neisseria gonorrhoeae JW-31 (minimum inhibitory concentration for penicillin G, less than 0.007 microgram/ml) resulted in cellular lysis after a lag of 30 min. Penicillin markedly decreased the rate of peptidoglycan synthesis and enhanced the rate of hydrolysis of existing peptidoglycan. Hydrolysis was initiated immediately after addition of penicillin; cellular lysis did not occur until a considerable percentage of the peptidoglycan had been degraded. Cellular lysis was not due to penicillin per se but resulted from inhibition of cell wall synthesis. When cells were grown in media buffered with N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid at pH 6, penicillin did not cause lysis; however, at this pH, peptidoglycan hydrolysis occurred and cells lost viability at the same rate as in the control (pH 7.2). We suggest that the stability of gonococci grown at pH 6 is related to increased stability of ...
Journal of Bacteriology, 1974
The metabolism of glucose was examined in several clinical isolates of Neisseria gonorrhoeae . Ra... more The metabolism of glucose was examined in several clinical isolates of Neisseria gonorrhoeae . Radiorespirometric studies revealed that growing cells metabolized glucose by a combination on the Entner-Doudoroff and pentose phosphate pathways. A portion of the glyceraldehyde-3-phosphate formed via the Entner-Doudoroff pathway was recycled by conversion to glucose-6-phosphate. Subsequent catabolism of this glucose-6-phosphate by either the Entner-Doudoroff or pentose phosphate pathways yielded CO 2 from the original C6 of glucose. Enzyme analyses confirmed the presence of all enzymes of the Entner-Doudoroff, pentose phosphate, and Embden-Meyerhof-Parnas pathways. There was always a high specific activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) relative to that of 6-phosphogluconate dehydrogenase (EC 1.1.1.44). The glucose-6-phosphate dehydrogenase utilized either nicotinamide adenine dinucleotide phosphate or nicotinamide adenine dinucleotide as electron acceptor. Acetate w...
Journal of Bacteriology, 1981
Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas a... more Strains of Neisseria gonorrhoeae were treated with pyocin 611 131 (pyocin 103) from Pseudomonas aeruginosa PA103, and isogenic resistant variants were isolated. The interaction of pyocin-sensitive and isogenic pyocin-resistant strains with wheat germ agglutinin (WGA) agglutinated all pyocin-sensitive, but not pyocin-resistant, strains. Binding of WGA to three pyocin-sensitive strains and their isogenic pyocin-resistant variants was examined quantitatively by using fluorescein-conjugated lectin. Pyocin-resistant strains maximally bound one-third to one-eighth the quantity of WGA bound by isogenic-sensitive strains. Linear Scatchard plots revealed homogeneous WGA-binding sites on three pyocin-sensitive and one pyocin-resistant strains. Biphasic Scatchard plots, obtained with two pyocin-resistant strains, show that WGA-binding sites in these strains are heterogeneous. The number of WGA-binding sites for pyocin-sensitive organisms ranged from 8 x 10(5) to 1 x 10(6) sites per coccus and ...
Infection and Immunity, 1977
Fatty acids of various chain lengths (C 1 to C 24 ) were examined for their effects on growth, ox... more Fatty acids of various chain lengths (C 1 to C 24 ) were examined for their effects on growth, oxygen consumption, and in vitro reduced nicotinamide adenine dinucleotide oxidase activity of Neisseria gonorrhoeae CS-7. The growth inhibition caused by saturated fatty acids increased with increasing chain length to a maximum with palmitic acid (C 16 ). Stearic acid (C 18 ) and longer saturated fatty acids showed little inhibition of growth. However, unsaturated fatty acids of chain length C 16 to C 20 were inhibitory. Similar inhibition was observed with Bacillus subtilis and a deep rough mutant of Salmonella typhimurium. Wildtype S. typhimurium and Pseudomonas aeruginosa were more resistant to medium-chain (C 7 to C 10 ) fatty acids and completely resistant to long-chain (C 12 to C 18 ) fatty acids. Thus, sensitivity of N. gonorrhoeae to long-chain fatty acids appears to be related to the permeability of the outer membrane. Growth inhibition by short-chain (C 1 to C 6 ) fatty acids wa...
Journal of Clinical Microbiology, 1983
Various factors affect the sensitivity of Neisseria gonorrhoeae to physiological levels of hydrop... more Various factors affect the sensitivity of Neisseria gonorrhoeae to physiological levels of hydrophobic molecules. A total of 98 N. gonorrhoeae strains from rectal, cervical, and urethral cultures of homosexual men and heterosexual men and women were examined for their sensitivities to fecal lipids. Isolates were characterized according to cell envelope phenotype, auxotype, and protein I serogroup. Although cell envelope phenotype was an important factor in the resistance of this organism to fecal lipids (Mtr phenotype greater than wild type greater than Env phenotype), other factors were also of importance. AHU- strains (strains having a requirement for arginine, hypoxanthine, and uracil) uniformly exhibited a wild-type envelope phenotype but were as sensitive to fecal lipids as were Env strains. The protein I serogroup was not a factor in determining the sensitivity of wild-type envelope phenotype non-AHU- strains to fecal lipids. However, sexual preference and site of isolation we...
Journal of Clinical Microbiology, 1981
Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity ... more Incubation of gonococci under conditions optimal for autolysis resulted in increased sensitivity and enhancement of the coagglutination reaction of the Phadebact gonococcus test. These conditions included an alkaline pH (pH 8.3) and the presence of divalent cation chelators such as ethylenediaminetetraacetic acid or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. Heating cell suspensions at 90 degrees C for 15 min before assay by coagglutination produced a further increase in sensitivity and enhancement of the reaction. Gonococcal lipopolysaccharide was found to be an important antigen in these coagglutination reactions. The detection of lipopolysaccharide was markedly enhanced by the addition of chelating agents.
Journal of Bacteriology, 1997
In this study, we have mapped the promoter region of the Neisseria gonorrhoeae ferric iron bindin... more In this study, we have mapped the promoter region of the Neisseria gonorrhoeae ferric iron binding protein-encoding gene fbpA, determined the start point of transcription, and examined the accumulation of fbpA mRNA Primer extension analysis of the fbpA promoter region indicated a single transcriptional start site located 51 bp upstream of the ATG translational start site. Northern blot analysis with a 200-bp fbpA structural gene probe detected one transcript of 1.0 kb in RNAs extracted from gonococcal cultures grown under iron-restricted conditions; the 1.0-kb transcript was observed to accumulate at a steady rate throughout the growth cycle. In comparison, in cultures grown under iron-sufficient conditions, the intensity of the 1.0-kb transcript was reduced considerably. Isolation of total RNA from rifampin-treated cells indicated that the half-life of the 1.0-kb fbpA transcript in cells grown under iron-restricted conditions was 1.2 +/- 0.2 min, while that of the 1.0-kb fbpA trans...
Journal of Medical Microbiology, 1987
The production of toxic shock syndrome toxin-1 (TSST-1) was studied in batch and continuous cultu... more The production of toxic shock syndrome toxin-1 (TSST-1) was studied in batch and continuous culture of Staphylococcus aureus strain 1 169 in a carbohydratefree chemically defined medium (CDM). In continuous culture oxygen-and argininelimitation were required for steady-state TSST-1 synthesis. Aeration suppressed toxin synthesis. The amount of TSST-1 per mg dry weight (specific toxin) at dilution rates from 0.05 to 0.15 h-was inversely proportional to the dilution rate. Protease activity increased with increasing dilution rates. In batch culture, TSST-1 began to accumulate in the medium towards the end of the exponential phase of growth, after a critical cell mass was attained. Maximum specific toxin production was observed in medium with an initial pH between 6.5 and 7.0. Growth and toxin synthesis took place in anaerobic conditions when CDM was supplemented with pyruvate and uracil. The Mg++ concentration had no effect on the specific toxin in anaerobic conditions. In aerobic conditions, specific toxin increased c. 23-fold as the Mg + + concentrations increased to 0.4 mM. Further increases in the Mg+ + concentration resulted in a reduction in specific toxin.
Journal of Infectious Diseases, 1986
In 1984 and 1985, outbreaks of genital ulcers occurred in Florida and New York. Initial investiga... more In 1984 and 1985, outbreaks of genital ulcers occurred in Florida and New York. Initial investigations for syphilis, herpes simplex, Chlamydia trachomatis, and Haemophilus ducreyi did not implicate any of these organisms as etiologic agents. From the results of dot-immunobinding assays, we found that sera from the patients had higher levels of IgM (30 [47.6%] of 63 patients) and IgG (22 [34.9%] of 63 patients) reactivities with an outer-membrane preparation from H. ducreyi strain CIP542 than with outer-membrane preparations from Haemophilus influenzae ATCC 10211 or Haemophilus parainfluenzae ATCC 7901. In contrast, sera from 35 patients in the control group did not react with any of the outer-membrane preparations (P less than .01 for both IgM and and IgG reactivity), nor did sera from eight individuals with disease caused by H. influenzae (P = .051 for IgM reactivity, P = .02 for IgG reactivity). Indirect immunofluorescence assay using a monoclonal antibody reactive with outer-membrane preparations from H. ducreyi strain CIP542 stained organisms in smears of lesion material from genital ulcers from three of six patients. These results suggested that the cause of both outbreaks of genital ulcers was H. ducreyi which was subsequently isolated in both geographic areas.
Journal of Infectious Diseases, 1987
Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fi... more Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fimbriae by subcutaneous implantation. Depending upon monkey species, from eight to 20 implants could be established in each animal. Animals were given estrogen before percutaneous inoculation of the autografts with Chlamydia. Acute inflammatory changes were found in homografts examined in the first week after infection, with chronic inflammatory changes noted thereafter. Chlamydial inclusions were detected within fimbrial epithelial cells up to seven days postinoculation by fluorescent-antibody staining and immunoperoxidase staining with C. trachomatis-specific monoclonal antibody. Organisms were recovered from autografts up to five days after infection. Analysis of serum antibody by microimmunofluorescence revealed that serotype E-specific antibody of both IgM and IgG classes was produced after infection. We conclude that subcutaneously implanted fallopian tube autografts may provide a useful primate model for kinetic studies of chlamydial infection and immunity.
The Journal of Infectious Diseases, 1998
Antimicrobial Agents and Chemotherapy, 1980
All 11 clinically significant isolates of Branhamella catarrhalis examined in this study were fou... more All 11 clinically significant isolates of Branhamella catarrhalis examined in this study were found to produce f8-lactamase. The enzyme was apparently not plasmid associated since extrachromosomal deoxyribonucleic acid was not detected in any ofthe strains. The fi-lactamase activity of all strains was significantly depressed by the fi-lactamase inhibitors clavulanic acid and CP 45899. Based on comparisons of relative susceptibility to various ,B-lactam antibiotics, it was inferred that the ,B-lactamase of B. catarrhalis was significantly more active against penicillin congeners than against cephalosporin congeners. Most strains were not inhibited by readily achievable serum concentrations of the pencilhinasesensitive penicillins, penicillin G, ampicillin, and amoxicillin. Methicillin was equally ineffective. With rare exceptions, most strains of B. catarrhalis were inhibited by achievable serum concentrations of seven cephalosporins (cephalothin, cephapirin, cephaloridine, cephalexin, cephamandole, cefaclor, and cefuroxin) and one cephamycin (cefoxitin). All strains were uniformly resistant to clindamycin but were inhibited by achievable serum concentrations of erythromycin, tetracycline, chloramphenicol, and trimethoprimn-sulfamethoxazole. Comparison of geometric mean minimum inhibitory concentrations of all antimicrobial agents tested suggested that B. catarrhalis was most susceptible to cefoxitin, erythromycin, and tetracycline. Branhamella (Neisseria) catarrhalis, previously considered a harmless, upper respiratory tract commensal of humans (9), is now recognized as the etiological agent of significant disease in humans. It has been implicated in a wide variety of infectious processes (G.
Public health reports (Washington, D.C. : 1974)
Prehospital and Disaster Medicine, 2003
military in operational functions, and their spokesmen have taken part in broadcast interviews-bu... more military in operational functions, and their spokesmen have taken part in broadcast interviews-but purely at a factual operational level. The major issues still under review include: (1) Who is telling me? and (2) Can I trust them? Authorities must face the "fright factors" and "media triggers" and be ready in advance. But, there is a danger in having off-the-shelf, preprepared material that does not cover the precise details of a particular disruptive incident. Better to have generic material that can be adapted and prearranged conduits that can accept material at a few hours' notice.
Infection and Immunity, 1974
The effects of progesterone on the growth of pathogenic and nonpathogenic species of Neisseria we... more The effects of progesterone on the growth of pathogenic and nonpathogenic species of Neisseria were studied in liquid cultures. Only strains of N. gonorrhoeae and N. meningitidis were highly sensitive to growth inhibition by progesterone. This inhibitory effect was either bacteriostatic or bactericidal, depending upon the ratio of progesterone concentration to cell mass. The site of progesterone inhibition appeared to be located in the cell membrane; >86% of [4- 14 C]progesterone was recovered in the lipid-containing cell fractions. Membrane preparations from N. gonorrhoeae bound progesterone more efficiently than those from progesterone-insensitive cells. In addition, progesterone significantly inhibited the activity of the membrane-associated enzymes reduced nicotinamide adenine dinucleotide oxidase and (cytochrome b ) l -lactate dehydrogenase.
Infection and Immunity, 1986
Several iron-regulated proteins of Neisseria gonorrhoeae have been reported. One of these, a 37,0... more Several iron-regulated proteins of Neisseria gonorrhoeae have been reported. One of these, a 37,000-molecular-weight protein (37K protein), appears to be common to all gonococcal isolates. Recently, the occurrence of a similar protein has also been noted in N. meningitidis. The gonococcal 37K protein has been purified and used to produce both rabbit monospecific antiserum and murine monoclonal antibodies. Using these antibody reagents, we analyzed 57 strains from nine species of Neisseria and the closely related organism Branhamella catarrhalis for the presence of proteins antigenically related to the gonococcal 37K protein. Strains grown on medium with low iron content were probed for antigenic reactivity by Western blot techniques and an enzyme-linked immunosorbent assay. Proteins which cross-reacted with the rabbit monospecific antiserum were designated as AgR-37K proteins. The data indicated that the AgR-37K proteins were conserved among the 40 strains of N. gonorrhoeae, N. meni...