Characterization of Enterococci- and ESBL-Producing Escherichia coli Isolated from Milk of Bovides with Mastitis in Egypt

This study aimed to investigate the prevalence and antimicrobial resistance of enterococci- and ESBL-producing E. coli isolated from milk of bovine mastitis cases in Egypt. Fifty milk samples of dairy animals were collected from localities in the Nile Delta region of Egypt. Isolates were identified using MALDI-TOF MS, and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistance-associated genes. Seventeen Enterococcus isolates and eight coliform isolates could be cultivated. Vancomycin resistance rate was high in Ent. faecalis. The VITEK 2 system confirmed all E. coli isolates as ESBL-producing. All Ent. faecalis isolates harbored erm(B), tetL and aac-aphD genes. The vanA gene was detected in Ent. faecalis isolate, vanB was found in other Enterococcus, while one isolate of E. casseliflavus exhibited the vanA gene. E. coli isolates exhibited high prevalence of erm(B) and tetL. E. coli isolates were analyzed by DNA microarray analysis. Four isolates were determined by O-serotyping as O8 (n = 1), O86 (n = 2) and O157 (n = 1). H-serotyping resulted in H11, H12, H21 (two isolates each) and one was of H16 type. Different virulence-associated genes were detected in E. coli isolates including lpfA, astA, celB, cmahemL, intI1 and intI2, and the iroN gene was identified by DNA microarray analysis.

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Characterization of Staphylococci and Streptococci Isolated from Milk of Bovides with Mastitis in Egypt

Pathogens ◽

10.3390/pathogens9050381 ◽

2020 ◽

Vol 9 (5) ◽

pp. 381

Author(s):

Wedad Ahmed ◽

Heinrich Neubauer ◽

Herbert Tomaso ◽

Fatma Ibrahim El Hofy ◽

Stefan Monecke ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Microarray Analysis ◽

Streptococcus Agalactiae ◽

Nile Delta ◽

Meca Gene ◽

Resistance Rate ◽

Coagulase Negative Staphylococci ◽

Flight Mass Spectrometry ◽

Streptococcus Gallolyticus ◽

Broth Microdilution Method

The aim of this study was to characterize staphylococci and streptococci in milk from Egyptian bovides. In total, 50 milk samples were collected from localities in the Nile Delta region of Egypt. Isolates were cultivated, identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility testing was performed by the broth microdilution method. PCR amplifications were carried out, targeting resistance-associated genes. Thirty-eight Staphylococcus isolates and six Streptococcus isolates could be cultivated. Staphylococcus aureus isolates revealed a high resistance rate to penicillin, ampicillin, clindamycin, and erythromycin. The mecA gene defining methicillin-resistant Staphylococcus aureus, erm(C) and aac-aphD genes was found in 87.5% of each. Coagulase-negative staphylococci showed a high prevalence of mecA, blaZ and tetK genes. Other resistance-associated genes were found. All Streptococcus dysgalactiae isolates carried blaZ, erm(A), erm(B), erm(C) and lnuA genes, while Streptococcus suis harbored erm(C), aphA-3, tetL and tetM genes, additionally. In Streptococcus gallolyticus, most of these genes were found. The Streptococcus agalactiae isolate harbored blaZ, erm(B), erm(C), lnuA, tetK, tetL and tetM genes. Streptococcus agalactiae isolate was analyzed by DNA microarray analysis. It was determined as sequence type 14, belonging to clonal complex 19 and represented capsule type VI. Pilus and cell wall protein genes, pavA, cadD and emrB/qacA genes were identified by microarray analysis.

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Genes of Escherichia coli O157:H7 That Are Involved in High-Pressure Resistance

Applied and Environmental Microbiology ◽

10.1128/aem.72.4.2661-2671.2006 ◽

2006 ◽

Vol 72 (4) ◽

pp. 2661-2671 ◽

Cited By ~ 75

Author(s):

Aaron S. Malone ◽

Yoon-Kyung Chung ◽

Ahmed E. Yousef

Keyword(s):

Escherichia Coli ◽

High Pressure ◽

Microarray Analysis ◽

Dna Microarray ◽

Spontaneous Mutation ◽

Cluster Assembly ◽

E Coli ◽

Dna Microarray Analysis ◽

Pressure Resistance ◽

K 12

ABSTRACT Seventeen Escherichia coli O157:H7 strains were treated with ultrahigh pressure at 500 MPa and 23 ± 2°C for 1 min. This treatment inactivated 0.6 to 3.4 log CFU/ml, depending on the strain. The diversity of these strains was confirmed by pulsed-field gel electrophoresis (PFGE) analysis, and there was no apparent association between PFGE banding patterns and pressure resistance. The pressure-resistant strain E. coli O157:H7 EC-88 (0.6-log decrease) and the pressure-sensitive strain ATCC 35150 (3.4-log decrease) were treated with a sublethal pressure (100 MPa for 15 min at 23 ± 2°C) and subjected to DNA microarray analysis using an E. coli K-12 antisense gene chip. High pressure affected the transcription of many genes involved in a variety of intracellular mechanisms of EC-88, including the stress response, the thiol-disulfide redox system, Fe-S cluster assembly, and spontaneous mutation. Twenty-four E. coli isogenic pairs with mutations in the genes regulated by the pressure treatment were treated with lethal pressures at 400 MPa and 23 ± 2°C for 5 min. The barotolerance of the mutants relative to that of the wild-type strains helped to explain the results obtained by DNA microarray analysis. This study is the first report to demonstrate that the expression of Fe-S cluster assembly proteins and the fumarate nitrate reductase regulator decreases the resistance to pressure, while sigma factor (RpoE), lipoprotein (NlpI), thioredoxin (TrxA), thioredoxin reductase (TrxB), a trehalose synthesis protein (OtsA), and a DNA-binding protein (Dps) promote barotolerance.

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Longitudinal Surveillance and Risk Assessment of Resistance in Escherichia coli to Enrofloxacin from a Large-Scale Chicken Farm in Hebei, China

Antibiotics ◽

10.3390/antibiotics10101222 ◽

2021 ◽

Vol 10 (10) ◽

pp. 1222

Author(s):

Kaixuan Guo ◽

Yue Zhao ◽

Luqing Cui ◽

Zhengzheng Cao ◽

Fan Zhang ◽

...

Keyword(s):

Escherichia Coli ◽

Drug Resistance ◽

Large Scale ◽

Bacterial Resistance ◽

Rank Correlation ◽

Resistance Rate ◽

Multi Drug Resistance ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method

The purpose of this study was to investigate the changes of resistance phenotype and plasmid-mediated quinolone resistance genes (PMQRs) in Escherichia coli (E. coli) during enrofloxacin (ENR) administration in different breeding cycles. In 2020, 983 strains of E. coli were isolated from different samples in different cycles at the broiler farm with the largest single batch of slaughter capacity in Hebei Province, China. All samples were from chicken, environmental, and human sources. The sensitivity of the isolates to various antibiotics was determined by broth microdilution method. The findings of this study include: (1) the total isolation rate of E. coli in the four cycles was 63.83% (983/1540); (2) the average resistance rate of E. coli from 1-day-old chickens to enrofloxacin was as high as 75% in each cycle, and with the use of enrofloxacin, the resistance rate of E. coli from chickens gradually increased to 100%; (3) 107 strains of E. coli randomly selected from different cycles and sources demonstrated the multi-drug resistance phenotypes. The highest resistance rate was doxycycline (100%), and the lowest was erythromycin (54.21%); (4) the detection rate of PMQRs of E. coli from chickens in different cycles were always higher than that from environmental and human. In particular, the PMQRs pollution rate of chicken seedlings in each cycle was generally higher than that of other links; (5) We used SPSS software to analyze the Kendall rank correlation of the experimental data. The resistance of E. coli isolated from this farm to ciprofloxacin (CIP) may increase along with the increase of resistance to enrofloxacin (Kendall’s tau-b = 0.190, p = 0.021). All these data highlight the serious problem of bacterial resistance in this farm. Therefore, it is urgent to provide guidance for the prevention and control of colibacillosis and drug resistance in this farm.

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The Potential of 2-aza-8-Oxohypoxanthine as a Cosmetic Ingredient

Cosmetics ◽

10.3390/cosmetics8030060 ◽

2021 ◽

Vol 8 (3) ◽

pp. 60

Author(s):

Hisae Aoshima ◽

Masayuki Ito ◽

Rinta Ibuki ◽

Hirokazu Kawagishi

Keyword(s):

Gene Expression ◽

Cell Proliferation ◽

Microarray Analysis ◽

Dna Microarray ◽

Cell Activation ◽

Skin Barrier ◽

Efficacy Evaluation ◽

Activation Effect ◽

Expression Levels ◽

Dna Microarray Analysis

In this study, we verified the effects of 2-aza-8-oxohypoxanthine (AOH) on human epidermal cell proliferation by performing DNA microarray analysis. Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, which measures mitochondrial respiration in normal human epidermal keratinocyte (NHEK) cells. Gene expression levels were determined by DNA microarray analysis of 177 genes involved in skin aging and disease. AOH showed a significant increase in cell viability at concentrations between 7.8 and 31.3 μg/mL and a significant decrease at concentrations above 250 μg/mL. DNA microarray analysis showed that AOH significantly increased the gene expression of CLDN1, DSC1, DSG1, and CDH1 (E-cadherin), which are involved in intercellular adhesion and skin barrier functioning. AOH also up-regulated the expression of KLK5, KLK7, and SPIMK5, which are proteases involved in stratum corneum detachment. Furthermore, AOH significantly stimulated the expression of KRT1, KRT10, TGM1, and IVL, which are considered general differentiation indicators, and that of SPRR1B, a cornified envelope component protein. AOH exerted a cell activation effect on human epidermal cells. Since AOH did not cause cytotoxicity, it was considered that the compound had no adverse effects on the skin. In addition, it was found that AOH stimulated the expression levels of genes involved in skin barrier functioning by DNA microarray analysis. Therefore, AOH has the potential for practical use as a cosmetic ingredient. This is the first report of efficacy evaluation tests performed for AOH.

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DNA Microarray Analysis Identifies CKS2 and LEPR as Potential Markers of Meningioma Recurrence

The Oncologist ◽

10.1634/theoncologist.2010-0249 ◽

2011 ◽

Vol 16 (10) ◽

pp. 1440-1450 ◽

Cited By ~ 13

Author(s):

Francesca Menghi ◽

Francesca N. Orzan ◽

Marica Eoli ◽

Mariangela Farinotti ◽

Emanuela Maderna ◽

...

Keyword(s):

Microarray Analysis ◽

Dna Microarray ◽

Dna Microarray Analysis ◽

Meningioma Recurrence

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Activity of Ceftazidime-Avibactam against Fluoroquinolone-Resistant Enterobacteriaceae and Pseudomonas aeruginosa

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05136-14 ◽

2015 ◽

Vol 59 (6) ◽

pp. 3059-3065 ◽

Cited By ~ 14

Author(s):

C. Pitart ◽

F. Marco ◽

T. A. Keating ◽

W. W. Nichols ◽

J. Vila

Keyword(s):

Pseudomonas Aeruginosa ◽

Resistant Mutant ◽

Fluoroquinolone Resistance ◽

Cross Resistance ◽

Content Type ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method ◽

The Impact

ABSTRACTCeftazidime-avibactam and comparator antibiotics were tested by the broth microdilution method against 200Enterobacteriaceaeand 25Pseudomonas aeruginosastrains resistant to fluoroquinolones (including strains with the extended-spectrum β-lactamase [ESBL] phenotype and ceftazidime-resistant strains) collected from our institution. The MICs and mechanisms of resistance to fluoroquinolone were also studied. Ninety-nine percent of fluoroquinolone-resistantEnterobacteriaceaestrains were inhibited at a ceftazidime-avibactam MIC of ≤4 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference). Ceftazidime-avibactam was very active against ESBLEscherichia coli(MIC90of 0.25 mg/liter), ESBLKlebsiella pneumoniae(MIC90of 0.5 mg/liter), ceftazidime-resistant AmpC-producing species (MIC90of 1 mg/liter), non-ESBLE. coli(MIC90of ≤0.125 mg/liter), non-ESBLK. pneumoniae(MIC90of 0.25 mg/liter), and ceftazidime-nonresistant AmpC-producing species (MIC90of ≤0.5 mg/liter). Ninety-six percent of fluoroquinolone-resistantP. aeruginosastrains were inhibited at a ceftazidime-avibactam MIC of ≤8 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference), with a MIC90of 8 mg/liter. Additionally, fluoroquinolone-resistant mutants from each species tested were obtainedin vitrofrom two strains, one susceptible to ceftazidime and the other a β-lactamase producer with a high MIC against ceftazidime but susceptible to ceftazidime-avibactam. Thereby, the impact of fluoroquinolone resistance on the activity of ceftazidime-avibactam could be assessed. The MIC90values of ceftazidime-avibactam for the fluoroquinolone-resistant mutant strains ofEnterobacteriaceaeandP. aeruginosawere ≤4 mg/liter and ≤8 mg/liter, respectively. We conclude that the presence of fluoroquinolone resistance does not affectEnterobacteriaceaeandP. aeruginosasusceptibility to ceftazidime-avibactam; that is, there is no cross-resistance.

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DNA microarray analysis of global gene regulation by A-factor in Streptomyces griseus

Microbiology ◽

10.1099/mic.0.027862-0 ◽

2009 ◽

Vol 155 (7) ◽

pp. 2197-2210 ◽

Cited By ~ 37

Author(s):

Hirofumi Hara ◽

Yasuo Ohnishi ◽

Sueharu Horinouchi

Keyword(s):

Gene Expression ◽

Microarray Analysis ◽

Dna Microarray ◽

Streptomyces Griseus ◽

Exponential Growth Phase ◽

Mobility Shift ◽

Dna Microarray Analysis ◽

Regulatory Cascade ◽

Transcriptional Units ◽

Inducible Genes

A-factor (2-isocapryloyl-3R-hydroxymethyl-γ-butyrolactone) is a microbial hormone that triggers morphological differentiation and secondary metabolism in Streptomyces griseus. The effects of A-factor on global gene expression were determined by DNA microarray analysis of transcriptomes obtained with the A-factor-deficient mutant ΔafsA. A-factor was added at a concentration of 25 ng ml−1 to mutant ΔafsA at the middle of the exponential growth phase, and RNA samples were prepared from the cells grown after A-factor addition for a further 5, 15 and 30 min, and 1, 2, 4, 8 and 12 h. The effects of A-factor on transcription of all protein-coding genes of S. griseus were evaluated by comparison of the transcriptomes with those obtained from cells grown in the absence of A-factor. Analysis of variance among the transcriptomes revealed that 477 genes, which were dispersed throughout the chromosome, were differentially expressed during the 12 h after addition of A-factor, when evaluated by specific criteria. Quality threshold clustering analysis with regard to putative polycistronic transcriptional units and levels of upregulation predicted that 152 genes belonging to 74 transcriptional units were probable A-factor-inducible genes. Competitive electrophoretic mobility shift assays using DNA fragments including putative promoter regions of these 74 transcriptional units suggested that AdpA bound 37 regions to activate 72 genes in total. Many of these A-factor-inducible genes encoded proteins of unknown function, suggesting that the A-factor regulatory cascade of S. griseus affects gene expression at a specific time point more profoundly than expected.

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