bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA Microarray-Based Identification of Genes Associated with Glycopeptide Resistance in
Staphylococcus aureus
Authors: Cui Longzhu , Lian Jian-Qi , Neoh Hui-min , Reyes Ethel , Hiramatsu Keiichi 
Published: July 2005

ABSTRACT

Six pairs of transcription profiles between glycopeptide-intermediate
S. aureus
(GISA [or vancomycin-intermediate
S. aureus
; VISA]) and glycopeptide-susceptible
S. aureus
(vancomycin-susceptible
S. aureus
[VSSA], including glycopeptide-susceptible isogenic mutants from VISA) strains were compared using a microarray. Ninety-two open reading frames which were or tended to be increased in transcription in VISA in at least five out of six array combination pairs were evaluated for their effects on glycopeptide susceptibility by introducing these genes one by one into VSSA strain N315 to construct an overexpression library. By screening the library, 17 genes including 8 novel genes were identified as associated with glycopeptide resistance since their experimental overexpression reduced vancomycin and/or teicoplanin susceptibility of N315. The raised MICs of vancomycin and teicoplanin were 1.25 to 3.0 and 1.5 to 6.0 mg/liter, respectively, as compared to 1.0 mg/liter of N315. Three of these genes, namely
graF
,
msrA2
, and
mgrA
, also raised the oxacillin MIC from 8.0 mg/liter for N315 to 64 to ∼128 mg/liter when they were overexpressed in N315. Their contribution to vancomycin and beta-lactam resistance was further supported by gene knockout and
trans
-complementation assay. By using a plasmid-based promoter-green fluorescent protein gene (
gfp
) transcriptional fusion system,
graF
promoter-activated cells were purified, and subsequent susceptibility tests and Northern blot analysis demonstrated that the cells with up-regulated activity of
graF
promoter showed reduced susceptibility to vancomycin, teicoplanin, and oxacillin. In addition, cell morphology studies showed that
graF
and
msrA2
overexpression increased cell wall thickness of N315 by factors of 23.91 and 22.27%, respectively, accompanied by glycopeptide MIC increments of 3- to 6-fold, when they were overexpressed in N315. Moreover, extended experiments and analyses indicate that many of the genes identified above are related to the cell wall biosynthetic pathway, including active nutrient transport systems. We propose that the genes which raise glycopeptide resistance in
S. aureus
function toward altering the cell wall metabolic pathway.
Development and Validation of a Whole-Cell Inhibition Assay for Bacterial Methionine Aminopeptidase by Surface-Enhanced Laser Desorption Ionization-Time of Flight Mass Spectrometry
Authors: Greis Kenneth D. , Zhou Songtao , Siehnel Richard , Klanke Chuck , Curnow Alan , Howard Jeremy , Layh-Schmitt Gerlinde 
Published: July 2005

ABSTRACT
Bacterial methionine aminopeptidase (MAP) is a protease that removes methionine from the N termini of newly synthesized bacterial proteins after the peptide deformylase enzyme cleaves the formyl group from the initiator formylmethionine. MAP is an essential bacterial gene product and thus represents a potential target for therapeutic intervention. A fundamental challenge in the antibacterial drug discovery field is demonstrating conclusively that compounds with in vitro enzyme inhibition activity produce the desired antibacterial effect by interfering with the same target in whole bacterial cells. One way to address the activity of inhibitor compounds is by profiling cellular biomarkers in whole bacterial cells using compounds that are known inhibitors of a particular target. However, in the case of MAP, no specific inhibitors were available for such studies. Instead, a genetically attenuated MAP strain was generated in which MAP expression was placed under the control of an inducible arabinose promoter. Thus, MAP inhibition in whole cells could be mimicked by growth in the absence of arabinose. This genetically attenuated strain was used as a benchmark for MAP inhibition by profiling whole-cell lysates for unprocessed proteins using surface-enhanced laser desorption ionization-time of flight mass spectrometry (MS). Eight proteins between 4 and 14 kDa were confirmed as being unprocessed and containing the initiator methionine by adding back purified MAP to the preparations prior to MS analysis. Upon establishing these unprocessed proteins as biomarkers for MAP inhibition, the assay was used to screen small-molecule chemical inhibitors of purified MAP for whole-cell activity. Fifteen compound classes yielded three classes of compound with whole-cell activity for further optimization by chemical expansion. This report presents the development, validation, and implementation of a whole-cell inhibition assay for MAP.
Functional Analysis of Ca
IPT1
, a Sphingolipid Biosynthetic Gene Involved in Multidrug Resistance and Morphogenesis of
Candida albicans
Authors: Prasad Tulika , Saini Preeti , Gaur Naseem Akhtar , Vishwakarma Ram A. , Khan Luqman Ahmad , Haq Qazi M. Rizwanul , Prasad Rajendra 
Published: July 2005

ABSTRACT

In the present study we describe the isolation and functional analysis of a sphingolipid biosynthetic gene,
IPT1
, of
Candida albicans
. The functional consequence of the disruption of both alleles of
IPT1
was confirmed by mass analysis of its sphingolipid composition. The disruption of both alleles or a single allele of
IPT1
did not lead to any change in growth phenotype or total sphingolipid, ergosterol, or phospholipid content of the mutant cells. The loss of mannosyl diinositol diphosphoceramide [M(IP)
2
C] in the
ipt1
disruptant, however, resulted in increased sensitivity to drugs like 4-nitroquinoline oxide, terbinafine,
o
-phenanthroline, fluconazole, itraconazole, and ketoconazole. The increase in drug susceptibilities of
ipt1
cells was linked to an altered sphingolipid composition, which appeared to be due to the impaired functionality of Cdr1p, a major drug efflux pump of
C. albicans
that belongs to the ATP binding cassette superfamily. Our confocal and Western blotting results demonstrated that surface localization of green fluorescent protein-tagged Cdr1p was affected in
ipt1
disruptant cells. Poor surface localization of Cdr1p resulted in an impaired ability to efflux fluconazole and rhodamine 6G. The effect of mannosyl inositol phosphoceramide accumulation in the
ipt1
mutant and the absence of M(IP)
2
C from the
ipt1
mutant on the efflux of drug substrates was very selective. The efflux of methotrexate, a specific substrate of CaMdr1p, another major efflux pump of major facilitator superfamily, remained unaffected in
ipt1
mutant cells. Interestingly, changes in sphingolipid composition affected the ability of mutant cells to form proper hyphae in various media. Taken together, our results demonstrate that an altered composition of sphingolipid, which is among the major constituents of membrane rafts, affects the drug susceptibilities and morphogenesis of
C. albicans
.
Six Groups of the OXY β-Lactamase Evolved over Millions of Years in
Klebsiella oxytoca
Authors: Fevre Cindy , Jbel Mehdi , Passet Virginie , Weill François-Xavier , Grimont Patrick A. D. , Brisse Sylvain 
Published: July 2005

ABSTRACT

The diversity and evolution of the class A OXY β-lactamase from
Klebsiella oxytoca
were investigated and compared to housekeeping gene diversity. The entire
bla
OXY
coding region was sequenced in 18 clinical isolates representative of
the four
K. oxytoca
β-lactamase gene groups
bla
OXY-1
to
bla
OXY-4
and of two
new groups identified here,
bla
OXY-5
(with four isolates with pI 7.2 and one with pI 7.7) and
bla
OXY-6
(with four isolates with pI 7.75 and three with pI 8.1). Genes
bla
OXY-5
and
bla
OXY-6
showed 99.8% within-group nucleotide similarity but differed from each other by 4.2% and from
bla
OXY-1
, their closest relative, by 2.5% and 2.9%, respectively. Antimicrobial susceptibility to β-lactams was
similar among OXY groups. Nucleotide sequence diversity of the 16S rRNA (1,454 bp),
rpoB
(940 bp),
gyrA
(383 bp), and
gapDH
(573 bp) genes was in agreement with the β-lactamase gene phylogeny. Strains with
bla
OXY-1
,
bla
OXY-2
,
bla
OXY-3
,
bla
OXY-4
, and
bla
OXY-6
genes formed five phylogenetic groups, named KoI, KoII, KoIII, KoIV, and KoVI, respectively. Isolates
harboring
bla
OXY-5
appeared to represent an emerging lineage within KoI. We estimated that the
bla
OXY
gene has been evolving within
K. oxytoca
for approximately 100 million years, using as
calibration the 140-million-year estimation of the
Escherichia coli
-
Salmonella enterica
split. These
results show that the
bla
OXY
gene has diversified along
K. oxytoca
phylogenetic lines over long periods
of time without concomitant evolution of the antimicrobial resistance phenotype.
Highly Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by TAK-220, an Orally Bioavailable Small-Molecule CCR5 Antagonist
Authors: Takashima Katsunori , Miyake Hiroshi , Kanzaki Naoyuki , Tagawa Yoshihiko , Wang Xin , Sugihara Yoshihiro , Iizawa Yuji , Baba Masanori 
Published: July 2005

ABSTRACTTAK-220 is a member of a novel class of chemokine receptor antagonists and is highly specific to CCR5, as determined by receptor binding and calcium mobilization assays. The compound selectively inhibited coreceptor-mediated entry of human immunodeficiency virus type 1 (HIV-1) into host cells and HIV-1 infection mediated by CCR5. TAK-220 inhibited the replication of six CCR5-using (R5) HIV-1 clinical isolates in peripheral blood mononuclear cells (PBMCs) with a mean 90% effective concentration of 13 nM. The anti-HIV-1 activity of TAK-220 was not affected by addition of high concentrations of human serum. It equally inhibited R5 HIV-1 replication in PBMCs obtained from eight different donors, irrespective of the levels of viral production. Furthermore, the anti-HIV-1 activity of TAK-220 was found to be subtype independent. TAK-220 did not induce CCR5 internalization but blocked the binding of two monoclonal antibodies that recognize the second extracellular loop of CCR5 in CCR5-expressing cells. These results suggest that TAK-220 selectively inhibits R5 HIV-1 replication by interfering with coreceptor-mediated entry of the virus into host cells. At a dose of 5 mg/kg of body weight, TAK-220 showed oral bioavailabilities of 9.5 and 28.9% in rats and monkeys, respectively. Thus, TAK-220 is a promising candidate for the treatment of HIV-1 infection.
Caspofungin Susceptibility Testing of
Candida inconspicua
: Correlation of Different Methods with the Minimal Fungicidal Concentration
Authors: Majoros L. , Kardos G. , Szabó B. , Sipiczki M. 
Published: July 2005

ABSTRACT

Minimal inhibitory and minimal fungicidal concentrations of caspofungin were determined for 48
Candida inconspicua
isolates. By using CLSI (formerly NCCLS) methodology with the partial inhibition endpoint criterion, caspofungin exhibited a good fungicidal effect against
C. inconspicua
(the MIC
90
was 0.25 μg/ml and the minimum fungicidal concentration [MFC] was 0.5 μg/ml after 24 h). Total inhibition yielded falsely elevated MICs, exceeding even the respective MFCs.
In Vitro Efficacy of the Combination of Ciprofloxacin and Cefotaxime against
Vibrio vulnificus
Authors: Kim Dong-Min , Lym Yong , Jang Sook Jin , Han Hulin , Kim Young Gi , Chung Choon-Hae , Hong Soon Pyo 
Published: July 2005

ABSTRACT

We performed time-kill studies of antimicrobial combinations that included minocycline, cefotaxime, and ciprofloxacin with
Vibrio vulnificus
ATCC 27562. Cefotaxime-plus-ciprofloxacin combinations acted synergistically against
V. vulnificus
in vitro, and this combination regimen can be a good choice as the empirical treatment for suspected necrotizing fasciitis due to
V. vulnificus
.
Antifungal Susceptibility of 596
Aspergillus fumigatus
Strains Isolated from Outdoor Air, Hospital Air, and Clinical Samples: Analysis by Site of Isolation
Authors: Guinea J. , Peláez T. , Alcalá L. , Ruiz-Serrano M. J. , Bouza E. 
Published: July 2005

ABSTRACT

We analyzed the activities of six antifungal drugs (amphotericin B, itraconazole, voriconazole, posaconazole, caspofungin, and micafungin) against 596
Aspergillus fumigatus
strains isolated from outdoor air, hospital air, and clinical samples. We did not find differences among the susceptibilities by site of isolation.
Preincubation of Pneumococci with β-Lactams Alone or Combined with Levofloxacin Prevents Quinolone-Induced Resistance without Increasing Intracellular Levels of Levofloxacin
Authors: Cottagnoud Philippe , Johnson Maggie , Cottagnoud Marianne , Piddock Laura 
Published: July 2005

ABSTRACT
Preincubation of pneumococci with sub-MIC concentrations of ceftriaxone (1/16× MIC), cefotaxime (1/8× MIC), and meropenem (1/4× MIC) alone or combined with levofloxacin (1/8× MIC) over 6 h prevents the emergence of levofloxacin-resistant mutants after 96 h of incubation but does not affect the intracellular accumulation of levofloxacin in two penicillin-resistant pneumococcal strains, suggesting a link between the mechanism of action of β-lactams and the emergence of quinolone-induced resistance in pneumococci.
Origin of Plasmid-Mediated Quinolone Resistance Determinant QnrA
Authors: Poirel Laurent , Rodriguez-Martinez Jose-Manuel , Mammeri Hedi , Liard Alain , Nordmann Patrice 
Published: July 2005

ABSTRACT

Plasmid-mediated resistance to quinolones is increasingly reported in studies of
Enterobacteriaceae
. Using a PCR-based strategy, a series of gram-negative species were screened for
qnrA
-like genes.
Shewanella algae
, an environmental species from marine and fresh water, was identified as its reservoir. This is a one of the very few examples of progenitor identification of an acquired antibiotic resistance gene.
Therapeutic Effect of ME1036 on Endocarditis Experimentally Induced by Methicillin-Resistant
Staphylococcus aureus
Authors: Nagura Jun , Kijima Koji , Kurazono Mizuyo , Takahata Sho , Sugano Toshie , Tanaka Yukari , Hirai Yoko , Yamada Keiko , Takayama Yoshihiro , Shitara Eiki , Yonezawa Minoru 
Published: July 2005

ABSTRACT

The efficacy of ME1036, a novel parenteral carbapenem, was compared with that of vancomycin by using a rabbit model of methicillin-resistant
Staphylococcus aureus
(MRSA) endocarditis. Compared with vancomycin, ME1036 reduced the bacterial counts in the vegetations at a lower dosage or over a shorter period of administration when it was used for the treatment of MRSA endocarditis.
Extended-Spectrum-β-Lactamase-Producing
Escherichia coli
Strains Isolated from Farm Animals from 1999 to 2002: Report from the Japanese Veterinary Antimicrobial Resistance Monitoring Program
Authors: Kojima Akemi , Ishii Yoshikazu , Ishihara Kanako , Esaki Hidetake , Asai Tetsuo , Oda Chitose , Tamura Yutaka , Takahashi Toshio , Yamaguchi Keizo 
Published: July 2005

ABSTRACT

A nationwide surveillance for antimicrobial susceptibility in
Escherichia coli
strains isolated from food-producing animals in Japan was conducted from 1999 to 2002. Eighteen cefazolin-resistant
E. coli
strains were isolated from broilers. Six were CTX-M-type producing, and eight were CMY-2 producing, while eight had mutations at the
ampC
promoter region.
Ceftazidime in Acute Myeloid Leukemia Patients with Febrile Neutropenia: Helpfulness of Continuous Intravenous Infusion in Maximizing Pharmacodynamic Exposure
Authors: Pea Federico , Viale Pierluigi , Damiani Daniela , Pavan Federica , Cristini Francesco , Fanin Renato , Furlanut Mario 
Published: July 2005

ABSTRACT

The pharmacokinetic-pharmacodynamic profile of a fixed 6-g daily continuous intravenous infusion of ceftazidime was assessed in 20 febrile neutropenic patients with acute myeloid leukemia. Mean steady-state ceftazidime concentrations averaging 40 mg/liter from day 2 on ensured maximized pharmacodynamic exposure (values close to four to five times the MIC breakpoint against
Pseudomonas aeruginosa
). However, large intra- and interindividual pharmacokinetic variability was documented throughout the study period.
Genotypic Diversity of Methicillin-Resistant
Staphylococcus aureus
Isolates in Korean Hospitals
Authors: Soo Ko Kwan , Kim Yeon-Sook , Song Jae-Hoon , Yeom Joon-Sup , Lee Hyuck , Jung Sook-In , Jeong Doo-Ryun , Kim Shin-Woo , Chang Hyun-Ha , Ki Hyun Kyun , Moon Chisook , Oh Won Sup , Peck Kyong Ran , Lee Nam Yong 
Published: July 2005

ABSTRACT

Ninety-six methicillin-resistant
Staphylococcus aureus
(MRSA) isolates from eight Korean hospitals were analyzed by multilocus sequence typing, SCC
mec
typing, and
spa
typing. The predominant genotype was ST5-MRSA-II of clonal complex 5, which was found in 36 isolates from six hospitals, but ST239-MRSA-III was also common. Overall, results showed a notable genotypic diversity of MRSA strains circulating in Korean hospitals.
An alternative protocol for DNA extraction from formalin fixed and paraffin wax embedded tissue
Authors: Coura R , Prolla J C , Meurer L , Ashton-Prolla P 
Published: July 2005

Background:DNA extraction from paraffin wax embedded tissue requires special protocols, and most described methods report an amplification success rate of 60–80%.Aims:To propose a simple and inexpensive protocol consisting of xylene/ethanol dewaxing, followed by a kit based extraction.Method:Xylene/ethanol dewaxing was followed by a long rehydration step and a kit based DNA extraction step.Results:This method produced a 100% amplification success rate for fragments of 121 to 227 bp for tamponated formalin fixed paraffin wax embedded tissue.Conclusion:This cost effective and non-laborious protocol can successfully extract DNA from tamponated formalin fixed paraffin wax embedded tissue and should facilitate the molecular analysis of a large number of archival specimens in retrospective studies.
Association of chronic fatigue syndrome with human leucocyte antigen class II alleles
Authors: Smith J , Fritz E L , Kerr J R , Cleare A J , Wessely S , Mattey D L 
Published: July 2005

Background:A genetic component to the development of chronic fatigue syndrome (CFS) has been proposed, and a possible association between human leucocyte antigen (HLA) class II antigens and chronic fatigue immune dysfunction has been shown in some, but not all, studies.Aims:To investigate the role of HLA class II antigens in CFS.Methods:Forty nine patients with CFS were genotyped for the HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the frequency of these alleles was compared with a control group comprising 102 normal individuals from the UK. All patients and controls were from the same region of England and, apart from two patients, were white.Results:Analysis by 2 × 2 contingency tables revealed an increased frequency of HLA-DQA1*01 alleles in patients with CFS (51.0%v35%; odds ratio (OR), 1.93; p  =  0.008). HLA-DQB1*06 was also increased in the patients with CFS (30.2%v20.0%; OR, 1.73, p  =  0.052). Only the association between HLA-DQA1*01 and CFS was significant in logistic regression models containing HLA-DQA1*01 and HLA-DRQB1*06, and this was independent of HLA-DRB1 alleles. There was a decreased expression of HLA-DRB1*11 in CFS, although this association disappeared after correction for multiple comparisons.Conclusions:CFS may be associated with HLA-DQA1*01, although a role for other genes in linkage disequilibrium cannot be ruled out.
Expression of human telomerase catalytic protein in gallbladder carcinogenesis
Authors: Luzar B , Poljak M , Cör A , Klopc̆ic̆ U , Ferlan-Marolt V 
Published: July 2005

Background:Telomerase catalytic subunit (hTERT) gene re-expression is a rate limiting step for the activity of telomerase, a key enzyme implicated in cellular immortalisation and transformation.Aims:To determine the potential role of hTERT protein in gallbladder carcinogenesis.Material/Methods:hTERT protein was analysed by means of immunohistochemistry in 89 gallbladder tissue samples: 16 normal epithelia, 14 reactive hyperplasias, 15 low grade dysplasias, 16 high grade dysplasias, and 28 adenocarcinomas. At least 200 nuclei were assessed for each slide and the mean number of positive signals for each nucleus was expressed as the hTERT index.Results:The mean hTERT index increased progressively with the degree of gallbladder epithelial abnormalities: from 0.03 in normal epithelia, 0.04 in hyperplastic epithelia, 0.25 in low grade dysplasia, 0.82 in high grade dysplasia, to 0.93 in adenocarcinoma. Statistical analysis revealed that three different groups of gallbladder epithelial changes can be distinguished according to the number of hTERT signals for each nucleus: (1) normal and regenerative gallbladder epithelium, (2) low grade dysplasia, and (3) high grade dysplasia and adenocarcinoma (p < 0.001).Conclusions:The occasional presence of hTERT protein in normal and regenerative gallbladder mucosa reflects their regenerative capacity. Nevertheless, significantly higher hTERT indices in low and high grade dysplastic epithelia and in gallbladder adenocarcinomas are probably a consequence of hTERT re-expression—an early event in the multistep process of gallbladder carcinogenesis.
Expression of p-STAT3 in human colorectal adenocarcinoma and adenoma; correlation with clinicopathological factors
Authors: Kusaba T , Nakayama T , Yamazumi K , Yakata Y , Yoshizaki A , Nagayasu T , Sekine I 
Published: July 2005

Background:The signal transducer and activator of transcription 3 (STAT3) is a key signalling molecule implicated in the regulation of growth and malignant transformation. Constitutive activation of STAT3 is seen in several tumour derived cell lines, and in a wide variety of human malignancies.Aims:To examine the relation between p-STAT3 (activated form of STAT3) expression and clinicopathological factors in human colorectal adenocarcinoma and adenoma.Methods:Immunohistochemical analyses were carried out on tissues from 44 colorectal adenomas and 95 colorectal adenocarcinomas, comprising 18 intramucosal carcinomas and 77 invasive carcinomas.Results:Seventy seven of these 139 samples (55.4%) showed immunoreactivity for p-STAT3. Positive staining for p-STAT3 was seen in 69 of the 95 carcinomas. Only eight of the 44 adenomas showed immunopositivity for p-STAT3, resulting in a significant difference between total adenocarcinomas and adenomas (p < 0.001). Among the 95 cases of colorectal adenocarcinoma, p-STAT3 immunoreactivity was significantly correlated with the depth of tumour invasion (p < 0.05), venous invasion (p < 0.05), lymph node metastasis (p < 0.05), and increasing stages of the Dukes’ classification (p < 0.01). Expression of p-STAT3 was detected by Western blot analysis in two different cultured human colorectal carcinoma cell lines and six colon carcinoma tissue samples obtained at surgery.Conclusion:This is the first study to report a significant correlation of p-STAT3 expression with the depth of tumour invasion. These findings suggest that p-STAT3 expression is an important factor related to carcinogenesis and/or tumour invasion of colorectal adenocarcinoma.