bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cathelicidin Peptides Inhibit Multiply Antibiotic-Resistant Pathogens from Patients with Cystic Fibrosis
Authors: Saiman Lisa , Tabibi Setareh , Starner Timothy D. , San Gabriel Pablo , Winokur Patricia L. , Jia Hong Peng , McCray Paul B. , Tack Brian F. 
Published: July 2002

ABSTRACT

Endogenous peptide antibiotics are under investigation as inhaled therapeutic agents for cystic fibrosis (CF) lung disease. The bactericidal activities of five cathelicidin peptides (LL37 [human], CAP18 [rabbit], mCRAMP [mouse], rCRAMP [rat], and SMAP29 [sheep]), three novel alpha-helical peptides derived from SMAP29 and termed ovispirins (OV-1, OV-2, and OV-3), and two derivatives of CAP18 were tested by broth microdilution assays. Their MICs were determined for multiply antibiotic-resistant
Pseudomonas aeruginosa
(
n
= 24),
Burkholderia cepacia
(
n
= 5),
Achromobacter xylosoxidans
(
n
= 5), and
Stenotrophomonas maltophilia
(
n
= 5) strains isolated from CF patients. SMAP29 was most active and inhibited mucoid and nonmucoid
P. aeruginosa
strains (MIC, 0.06 to 8 μg/ml). OV-1, OV-2, and OV-3 were nearly as active (MIC, 0.03 to 16 μg/ml), but CAP18 (MIC, 1.0 to 32 μg/ml), CAP18-18 (MIC, 1.0 to >32 μg/ml), and CAP18-22 (MIC, 0.5 to 32 μg/ml) had variable activities. LL37, mCRAMP, and rCRAMP were least active against the clinical isolates studied (MIC, 1.0 to >32 μg/ml). Peptides had modest activities against
S. maltophilia
and
A. xylosoxidans
(MIC range, 1.0 to > 32 μg/ml), but none inhibited
B. cepacia
. However, CF sputum inhibited the activity of SMAP29 substantially. The effects of peptides on bacterial cell membranes and eukaryotic cells were examined by scanning electron microscopy and by measuring transepithelial cell resistance, respectively. SMAP29 caused the appearance of bacterial membrane blebs within 1 min, killed
P. aeruginosa
within 1 h, and caused a dose-dependent, reversible decrease in transepithelial resistance within 5 h. The tested cathelicidin-derived peptides represent a novel class of antimicrobial agents and warrant further development as prophylactic or therapeutic agents for CF lung disease.
Antifungal Activities of Two New Azasordarins, GW471552 and GW471558, in Experimental Models of Oral and Vulvovaginal Candidiasis in Immunosuppressed Rats
Authors: Martinez Antonio , Ferrer Santiago , Santos Inmaculada , Jimenez Elena , Sparrowe John , Regadera Javier , De Las Heras Federico Gomez , Gargallo-Viola Domingo 
Published: July 2002

ABSTRACT

Sordarins constitute a new class of antifungal agents with a novel mechanism of action involving the selective inhibition of fungal protein synthesis. A further evolution of this class of antifungals has led to a new family of sordarin derivatives called azasordarins. The therapeutic efficacies of two new azasordarins, GW471552 and GW471558, were studied in experimental models of oral and vulvovaginal candidiasis in immunosuppressed rats. In all cases rats were immunosuppressed with dexamethasone in the drinking water. Oral candidiasis was established by inoculating 0.1 ml of a yeast suspension containing 5 × 10
8
cells of
Candida albicans
4711E with a cotton swab on three alternate days. Vulvovaginal candidiasis was established in ovariectomized and estrus-induced rats by intravaginal inoculation of 10
7
CFU of
C. albicans
4711E in 0.1 ml of saline. GW471552 and GW471558 were administered at 1, 5, and 10 mg/kg of body weight via the subcutaneous route. In oral candidiasis, azasordarins were administered each 8 h for 7 consecutive days, while in vaginal candidiasis the compounds were given each 4 h for 3 consecutive days. Antifungal activity of azasordarins was assessed by colony counts and by histological examination 1 day after treatment. In the oral infection model, GW471552 and GW471558 administered at 5 mg/kg significantly reduced (
P
< 0.05) the number of CFU of
C. albicans
compared with untreated controls. In addition, GW471552 and GW471558 given at 10 mg/kg eradicated
C. albicans
from the oral cavities of 100% of infected animals. Against vulvovaginal infection, both compounds showed significant therapeutic efficacy. GW471552 was able to eradicate the vaginal fungal burden at a dose of 10 mg/kg, and it significantly reduced the number of CFU of
C. albicans
in vaginas of rats treated with a dose of 5 mg/kg (
P
< 0.05). GW471558 showed greater efficacy, eradicating the fungal burden of 100% of infected rats at a dose of 5 mg/kg and significantly reducing (
P
< 0.05) the
C. albicans
vaginal counts even at a dose of 1 mg/kg. In both therapeutic efficacy studies, the histological findings confirmed the microbiological results. The experimental results presented show that the tested azasordarins are effective against oral and vulvovaginal candidiasis in immunosuppressed rats and could be promising antifungal agents for use in humans.
Activity of Oritavancin (LY333328), an Investigational Glycopeptide, Compared to That of Vancomycin against Multidrug-Resistant
Streptococcus pneumoniae
in an In Vitro Pharmacodynamic Model
Authors: Coyle Elizabeth A. , Rybak Michael J. 
Published: July 2002

ABSTRACT

In the past 2 decades, multidrug-resistant
Streptococcus pneumoniae
has been encountered with increasing frequency around the world. This has led to the need for newer agents in the treatment of
S. pneumoniae
infections. Oritavancin (LY333328) is a new glycopeptide antibiotic with activity against gram-positive organisms; however, there is limited information on the pharmacodynamics of oritavancin with respect to the treatment of
S. pneumoniae
. We utilized an in vitro pharmacodynamic model to compare the activity of oritavancin to that of vancomycin against two penicillin-, macrolide-, and ciprofloxacin-resistant
S. pneumoniae
isolates (R919 and R921) over a 48-h period. Both oritavancin and vancomycin achieved 99.9% (3-log) kill, with oritavancin achieving the limit of detection (10
2
CFU/ml) within 1 h and vancomycin achieving this limit at 24 h for both isolates. Detection of resistance was not observed for oritavancin or vancomycin during the 48-h experiments. The key pharmacodynamic parameter for oritavancin has not been well defined. In our experiment, the ratios of the area under the curve from 0 to 24 h to the MIC of oritavancin, oritavancin plus albumin, and vancomycin for both isolates were greater than 944.5, and the ratios of the maximum concentration of drug in serum to the MIC ranged from 73.7 to 7188.5. T>MIC was 100% for oritavancin and vancomycin for both isolates. Oritavancin is a unique and potent antimicrobial that warrants further investigation against multidrug-resistant
S. pneumoniae
.
Single-Dose Intraperitoneal Magainins Improve Survival in a Gram-Negative-Pathogen Septic Shock Rat Model
Authors: Cirioni Oscar , Giacometti Andrea , Ghiselli Roberto , Mocchegiani Federico , Fineo Anna , Orlando Fiorenza , Del Prete Maria Simona , Rocchi Marco , Saba Vittorio , Scalise Giorgio 
Published: July 2002

ABSTRACTThe therapeutic efficacies of three polycationic peptides selected among the class of the magainins (magainin I, magainin II, and magainin II amide), alone and combined with piperacillin, were investigated in a rat model of septic shock. Rats were given an intraperitoneal injection of 2 × 1010CFU ofEscherichia coliand randomized to receive intraperitoneally isotonic sodium chloride solution, 60 mg of piperacillin per kg of body weight, and 1 mg of each magainin per kg alone and combined with 60 mg of piperacillin per kg. The main outcome measures were bacterial growth in abdominal exudate and plasma, endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, and lethality. Treatments with the magainins achieved significant reductions of bacterial growth and plasma endotoxin and TNF-α concentrations. In general, treatments with the combinations of magainins and piperacillin demonstrated the highest efficacies.
Efficacy of Short-Course Ceftriaxone Therapy for
Borrelia burgdorferi
Infection in C3H Mice
Authors: Pavia Charles , Inchiosa Mario A. , Wormser Gary P. 
Published: July 2002

ABSTRACT

Ceftriaxone is highly effective clinically in patients with Lyme disease. We studied a representative invasive human isolate of
Borrelia burgdorferi
for which the MBC of ceftriaxone was 0.050 μg/ml. A once-per-day dosage regimen of ceftriaxone (50 mg/kg/dose) administered intramuscularly for 5 days was 100% effective in sterilizing tissue samples of C3H mice infected with this strain of
B. burgdorferi
, regardless of whether the mice were being treated concomitantly with a corticosteroid. Administration of the same five doses of ceftriaxone at 6-h intervals over just 24 h was also 100% effective. These experiments suggest that shorter courses of antibiotics than those currently recommended should be considered for study in patients with early uncomplicated Lyme disease.
Differential Expression of Methicillin Resistance by Different Biofilm-Negative
Staphylococcus epidermidis
Transposon Mutant Classes
Authors: Mack Dietrich , Sabottke Axel , Dobinsky Sabine , Rohde Holger , Horstkotte Matthias A. , Knobloch Johannes K.-M. 
Published: July 2002

ABSTRACT

Biofilm formation mediated by polysaccharide intercellular adhesin (PIA) is the major virulence factor of
Staphylococcus epidermidis
and is often associated with methicillin resistance. Transposon Tn
917
insertions leading to a biofilm-negative phenotype in the biofilm-producing
S. epidermidis
strain 1457 (
mecA
-negative) were transferred into the methicillin-resistant, biofilm-producing
S. epidermidis
1057 (
mecA
-positive) by transduction. According to their phenotypes and genotypes, the mutants could be separated into genetic classes I to IV (D. Mack, H. Rohde, S. Dobinsky, J. Riedewald, M. Nedelmann, J. K. M. Knobloch, H.-A. Elsner, and H. H. Feucht, Infect. Immun. 68:3799–3807, 2000). All transductants of
S. epidermidis
1057 had phenotypes for biofilm formation similar to those of the corresponding mutants of
S. epidermidis
1457. With a
mecA
-specific probe, identical hybridization patterns were observed for wild-type
S. epidermidis
1057 and all the transductants. There were minor changes in oxacillin MICs for Class II and III transductants compared to those for wild-type
S. epidermidis
1057. On population analysis,
S. epidermidis
1057 displayed a heterogeneous expression type of resistance with an oxacillin MIC of ≥6 μg/ml for more than 90% of the cells. An almost identical profile was observed with biofilm-negative class I mutants, where the transposon insertions inactivate the
icaADBC
gene locus essential for PIA synthesis. In contrast, class III mutants were more sensitive to oxacillin with a MIC of ≤1 μg/ml for more than 90% of the cells. The class IV mutant displayed homogenous resistance with a MIC of ≥50 μg/ml for more than 90% of the cells. On oxacillin gradient plates, the class II mutant displayed decreased resistance. Apparently, different independent mutations leading to a biofilm-negative phenotype of
S. epidermidis
by influencing expression of
icaADBC
on the level of transcription significantly influence the expression of methicillin resistance. However, transcription of
mecA
was not significantly altered in the different transductants compared to the wild type, independent of
mecA
induction with oxacillin, indicating that other mechanisms influencing phenotypic expression of methicillin resistance are involved.
Molecular Characterization of the
vanE
Gene Cluster in Vancomycin-Resistant
Enterococcus faecalis
N00-410 Isolated in Canada
Authors: Boyd D. A. , Cabral T. , Van Caeseele P. , Wylie J. , Mulvey M. R. 
Published: July 2002

ABSTRACT

The
vanE
operon was characterized from
Enterococcus faecalis
N00-410 (MIC of vancomycin = 24 μg/ml). The organization of the
vanE
operon was identical to that of the
vanC1
operon from
Enterococcus gallinarum
, with protein identities ranging from 46 to 63%. An open reading frame located downstream of the
vanE
operon showed significant homology to a number of integrase genes, all of which are located downstream of the chromosomal GMP synthase gene
guaA
.
Detection of a Variant Metallo-β-Lactamase, IMP-10, from Two Unrelated Strains of
Pseudomonas aeruginosa
and an
Alcaligenes xylosoxidans
Strain
Authors: Iyobe Shizuko , Kusadokoro Haruko , Takahashi Ayako , Yomoda Sachie , Okubo Toyoji , Nakamura Akio , O'Hara Koji 
Published: July 2002

ABSTRACT

The gene
bla
IMP-10
of a variant metallo-β-lactamase, IMP-10, had a single base replacement of G by T at nucleotide 145, which led to an amino acid alteration of Val49 to Phe compared to the IMP-1 enzyme, indicating that IMP-10 was a point mutation derivative of IMP-1. Highly purified enzymes revealed that IMP-10 was different from IMP-1 in its extremely low hydrolyzing activities for penicillins, such as benzylpenicillin, ampicillin, and piperacillin.
Molecular Characterization ofYarrowia lipolyticaandCandida zeylanoidesIsolated from Poultry
Authors: Deak T. , Chen J. , Beuchat L. R. 
Published: July 2002

ABSTRACTYeast isolates from raw and processed poultry products were characterized using PCR amplification of the internally transcribed spacer (ITS) 5.8S ribosomal DNA region (ITS-PCR), restriction analysis of amplified products, randomly amplified polymorphic DNA (RAPD) analysis, and pulsed-field gel electrophoresis (PFGE). ITS-PCR resulted in single fragments of 350 and 650 bp, respectively, from eight strains ofYarrowia lipolyticaand seven strains ofCandida zeylanoides. Digestion of amplicons withHinfI andHaeIII produced two fragments of 200 and 150 bp fromY. lipolyticaand three fragments of 350, 150, and 100 bp fromC. zeylanoides, respectively. Although these fragments showed species-specific patterns and confirmed species identification, characterization did not enable intraspecies typing. Contour-clamped heterogeneous electric field PFGE separated chromosomal DNA ofY. lipolyticainto three to five bands, most larger than 2 Mbp, whereas six to eight bands in the range of 750 to 2,200 bp were obtained fromC. zeylanoides. Karyotypes of both yeasts showed different polymorphic patterns among strains. RAPD analysis, using enterobacterial repetitive intergenic sequences as primers, discriminated between strains within the same species. Cluster analysis of patterns formed groups that correlated with the source of isolation. For ITS-PCR, extraction of DNA by boiling yeast cells was successfully used.
Immobilization with Metal Hydroxides as a Means To Concentrate Food-Borne Bacteria for Detection by Cultural and Molecular Methods
Authors: Lucore Lisa A. , Cullison Mark A. , Jaykus Lee-Ann 
Published: July 2002

ABSTRACT

The application of nucleic acid amplification methods to the detection of food-borne pathogens could be facilitated by concentrating the organisms from the food matrix before detection. This study evaluated the utility of metal hydroxide immobilization for the concentration of bacterial cells from dairy foods prior to detection by cultural and molecular methods. Using reconstituted nonfat dry milk (NFDM) as a model, two food-borne pathogens (
Listeria monocytogenes
and
Salmonella enterica
serovar Enteritidis) were concentrated from 25-ml samples by the sequential steps of clarification and high-speed centrifugation (designated primary concentration) and immobilization with zirconium hydroxide and low-speed centrifugation (designated secondary concentration). Sample volume reduction after immobilization with zirconium hydroxide was 50-fold, with total bacterial recoveries ranging from 78 to 96% of input for serovar Enteritidis and 65 to 96% of input for
L. monocytogenes
. Immobilized bacteria remained viable and could be enumerated by standard cultural procedures. When followed by RNA extraction and subsequent detection by reverse transcription (RT)-PCR, detection limits of 10
1
to 10
2
CFU/25 ml of reconstituted NFDM were achieved for both organisms. The bacterial-immobilization step was relatively nonspecific, resulting in recovery of >50% of the input cells when evaluated on a panel of representative bacterial strains of significance to foods. The method could be adapted to more complex dairy products, such as whole milk and ice cream, for which bacterial recoveries after immobilization ranged from 64 to >100%, with subsequent RT-PCR detection limits of ≥10
2
CFU/ml for whole milk and ≥10
1
CFU for ice cream for both serovar Enteritidis and
L. monocytogenes
. The bacterial-immobilization method is easy, rapid, and inexpensive and may have applications for the concentration of a wide variety of food-borne bacteria prior to detection by both conventional and alternative methods.
Isolation and Characterization of 2,3-Dichloro-1-Propanol-Degrading Rhizobia
Authors: Effendi Agus J. , Greenaway Steven D. , Dancer Brian N. 
Published: July 2002

ABSTRACT

2,3-Dichloro-1-propanol is more chemically stable than its isomer, 1,3-dichloro-2-propanol, and is therefore more difficult to degrade. The isolation of bacteria capable of complete mineralization of 2,3-dichloro-1-propanol was successful only from enrichments at high pH. The bacteria thus isolated were found to be members of the α division of the
Proteobacteria
in the
Rhizobium
subdivision, most likely
Agrobacterium
sp. They could utilize both dihaloalcohol substrates and 2-chloropropionic acid. The growth of these strains in the presence of 2,3-dichloro-1-propanol was strongly affected by the pH and buffer strength of the medium. Under certain conditions, a ladder of four active dehalogenase bands could be visualized from this strain in activity gels. The enzyme involved in the complete mineralization of 2,3-dichloro-1-propanol was shown to have a native molecular weight of 114,000 and consisted of four subunits of similar molecular weights.
A Serine Protease-Encoding Gene (
aprII
) of
Alteromonas
sp. Strain O-7 Is Regulated by the Iron Uptake Regulator (Fur) Protein
Authors: Tsujibo Hiroshi , Miyamoto Katsushiro , Okamoto Takashi , Orikoshi Hideyuki , Inamori Yoshihiko 
Published: July 2002

ABSTRACT

The ferric uptake regulator (Fur) box-like sequence was located upstream of the serine protease-encoding gene (
aprII
) from a marine bacterium,
Alteromonas
sp. strain O-7. To clarify whether the production of AprII (the gene product of
aprII
) is regulated by the environmental iron concentrations, this strain was cultured under iron-depleted or iron-rich conditions and the level of AprII in the culture supernatant was analyzed by Western blotting. The production of AprII was significantly repressed under iron-rich conditions. Northern hybridization analysis demonstrated that AprII biosynthesis was regulated by iron through the control of transcription. These results indicate that
aprII
is a new member of the iron regulon and plays an important role in the iron acquisition system of the strain. Furthermore, the gene encoding Fur was cloned and sequenced. The deduced amino acid sequence of the cloned Fur showed high sequence similarity with that from gram-negative bacteria.
Proteins Induced during Adaptation of
Acetobacter aceti
to High Acetate Concentrations
Authors: Steiner Peter , Sauer Uwe 
Published: July 2002

ABSTRACT

As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of
Acetobacter aceti
by two-dimensional gel electrophoresis. Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation. Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress. Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps). Here we present first microsequence information on such Aaps from
A. aceti
. Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced.
Bifidobacterial Diversity in Human Feces Detected by Genus-Specific PCR and Denaturing Gradient Gel Electrophoresis
Authors: Satokari Reetta M. , Vaughan Elaine E. , Akkermans Antoon D. L. , Saarela Maria , de Vos Willem M. 
Published: July 2002

ABSTRACT

We describe the development and validation of a method for the qualitative analysis of complex bifidobacterial communities based on PCR and denaturing gradient gel electrophoresis (DGGE).
Bifidobacterium
genus-specific primers were used to amplify an approximately 520-bp fragment from the 16S ribosomal DNA (rDNA), and the fragments were separated in a sequence-specific manner in DGGE. PCR products of the same length from different bifidobacterial species showed good separation upon DGGE. DGGE of fecal 16S rDNA amplicons from five adult individuals showed host-specific populations of bifidobacteria that were stable over a period of 4 weeks. Sequencing of fecal amplicons resulted in
Bifidobacterium
-like sequences, confirming that the profiles indeed represent the bifidobacterial population of feces.
Bifidobacterium adolescentis
was found to be the most common species in feces of the human adult subjects in this study. The methodological approach revealed intragenomic 16S rDNA heterogeneity in the type strain of
B. adolescentis
, E-981074. The strain was found to harbor five copies of 16S rDNA, two of which were sequenced. The two 16S rDNA sequences of
B. adolescentis
E-981074
T
exhibited microheterogeneity differing in eight positions over almost the total length of the gene.
Molecular Characterization of Cycloinulooligosaccharide Fructanotransferase from
Bacillus macerans
Authors: Kim Hwa-Young , Choi Yong-Jin 
Published: July 2002

ABSTRACT

Cycloinulooligosaccharide fructanotransferase (CFTase) converts inulin into cyclooligosaccharides of β-(2→1)-linked
d
-fructofuranose by catalyzing an intramolecular transfructosylation reaction. The CFTase gene was cloned and characterized from
Bacillus macerans
CFC1. The CFTase gene encoded a polypeptide of 1,333 amino acids with a calculated
M
r
of 149,563. Western blot and zymography analyses revealed that the CFTase with a molecular mass of 150 kDa (CFT150) was processed (between Ser389 and Phe390 residue) to form a 107-kDa protein (CFT107) in the
B. macerans
CFC1 cells. The processed CFT107 was similar in its mass to the previously purified CFTase from
B. macerans
CFC1. The CFT107 enzyme was produced by
B. macerans
CFC1 but was not detected from the recombinant
Escherichia coli
cells, indicating that the processing event occurred in a host-specific manner. The two CFTases (CFT150 and CFT107) exhibited the same enzymatic properties, such as influences of pH and temperature on the enzyme activity, the intermolecular transfructosylation ability, and the ability of hydrolysis of cycloinulooligosaccharides produced by the cyclization reaction. However, the thermal stability of CFT107 was slightly higher than that of CFT150. The most striking difference between the two enzymes was observed in their

K
m

values; the value for CFT150 (1.56 mM) was threefold lower than that for CFT107 (4.76 mM). Thus, the specificity constant (
k
cat
/

K
m

) of CFT150 was about fourfold higher than that of CFT107. These results indicated that the N-terminal 358-residue region of CFT150 played a role in increasing the enzyme's binding affinity to the inulin substrate.