141 research outputs found
Antimicrobial resistance of Campylobacter isolates from small scale and backyard chicken in Kenya
Background Thermophilic Campylobacter species are a major cause of bacterial
foodborne diarrhoea in humans worldwide. Poultry and their products are the
predominant source for human campylobacteriosis. Resistance of Campylobacter
to antibiotics is increasing worldwide, but little is known about the
antibiotic resistance in Campylobacter isolated from chicken in Kenya. In this
study, 35 suspected Campylobacter strains isolated from faeces and cloacal
swabs of chicken were tested for their susceptibility to seven antibiotics
using a broth microdilution assay and molecular biological investigations.
Results Overall, DNA of thermophilic Campylobacter was identified in 53
samples by PCR (34 C. jejuni, 18 C. coli and one mix of both species) but only
35 Campylobacter isolates (31 C. jejuni and 4 C. coli) could be re-cultivated
after transportation to Germany. Isolates were tested for their susceptibility
to antibiotics using a broth microdilution assay. Additionally, molecular
biological detection of antibiotic resistance genes was carried out. C. jejuni
isolates showed a high rate of resistance to nalidixic acid, tetracycline and
ciprofloxacin of 77.4, 71.0 and 71.0 %, respectively. Low resistance (25.8 %)
was detected for gentamicin and chloramphenicol. Multidrug resistance in C.
jejuni could be detected in 19 (61.3 %) isolates. Resistance pattern of C.
coli isolates was comparable. Resistance to ciprofloxacin was confirmed by
MAMA–PCR and PCR–RFLP in all phenotypically resistant isolates. The tet(O)
gene was detected only in 54.5 % of tetracycline resistant C. jejuni isolates.
The tet(A) gene, which is also responsible for tetracycline resistance, was
found in 90.3 % of C. jejuni and in all C. coli isolates. Thirteen
phenotypically erythromycin-resistant isolates could not be characterised by
using PCR–RFLP and MAMA–PCR. Conclusions To the best of our knowledge, this
study is the first report about resistance to antibiotics in thermophilic
Campylobacter originating from chicken in Kenya. Campylobacter spp. show a
high level of resistance to ciprofloxacin, nalidixic acid and tetracycline but
also a remarkable one to chloramphenicol and gentamicin and they are multidrug
resistant. Resistance to antibiotics is a global public health concern. In
Kenya, resistance surveillance needs further attention in the future. Efforts
to establish at least a National Laboratory with facilities for performing
phenotypic and genotypic characterization of thermophilic Campylobacter is
highly recommended
Genotyping and antibiotic resistance of thermophilic Campylobacter isolated from chicken and pig meat in Vietnam
Background Campylobacter species are recognized as the most common cause of
foodborne bacterial gastroenteritis in humans. In this study nine
Campylobacter strains isolated from chicken meat and pork in Hanoi, Vietnam,
were characterized using molecular methods and tested for antibiotic
resistance. Results The nine isolates (eight C. jejuni and one C. coli) were
identified by multiplex PCR, and tested for the presence or absence of 29 gene
loci associated with virulence, lipooligosaccharide (LOS) biosynthesis and
further functions. flaA typing, multilocus sequence typing and microarray
assay investigation showed a high degree of genetic diversity among these
isolates. In all isolates motility genes (flaA, flaB, flhA, fliM),
colonization associated genes (cadF, docB), toxin production genes (cdtA,
cdtB, secD, secF), and the LOS biosynthesis gene pglB were detected. Eight
gene loci (fliY, virB11, Cje1278, Cj1434c, Cj1138, Cj1438c, Cj1440c, Cj1136)
could not be detected by PCR. A differing presence of the gene loci ciaB (22.2
%), Cje1280 (77.8 %), docC (66.7 %), and cgtB (55.6 %) was found. iamA, cdtC,
and the type 6 secretion system were present in all C. jejuni isolates but not
in C. coli. flaA typing resulted in five different genotypes within C. jejuni,
MLST classified the isolates into seven sequence types (ST-5155, ST-6736,
ST-2837, ST-4395, ST-5799, ST-4099 and ST-860). The microarray assay analysis
showed a high genetic diversity within Vietnamese Campylobacter isolates which
resulted in eight different types for C. jejuni. Antibiotic susceptibility
profiles showed that all isolates were sensitive to gentamicin and most
isolates (88.8 %) were sensitive to chloramphenicol, erythromycin and
streptomycin. Resistance rates to nalidixic acid, tetracycline and
ciprofloxacin were 88.9, 77.8 and 66.7 %, respectively. Conclusions To the
best of our knowledge, this study is the first report that shows high genetic
diversity and remarkable antibiotic resistance of Campylobacter strains
isolated from meat in Vietnam which can be considered of high public health
significance. These preliminary data show that large scale screenings are
justified to assess the relevance of Campylobacter infections on human health
in Vietnam
Synthesis and Biocidal Activity of Some Naphthalene-Based Cationic Surfactants
In this study, different cationic surfactants were prepared by reacting dodecyl bromide with tertiary amines to produce a series of quaternary ammonium salts that were converted subsequently to stannous and cobalt cationic complexes via complexing them with stannous (II) or cobalt (II) ions. Surface properties such as surface- and interfacial-tension, and the emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, minimum surface area, tension lowering efficiency and effectiveness were studied. The free energy of micellization and adsorption were calculated. Antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which was measured against six strains of a representative group of microorganisms. The antimicrobial activity of some of the prepared surfactants against sulfate reducing bacteria was determined by the dilution method. FTIR spectra, elemental analysis and a H1 NMR spectrum were examined to confirm compound structure and purity. The results obtained indicate that these compounds have good surface properties and good biocidal effect on broad spectrum of micro organisms
Elevated serum neutrophil elastase is related to prehypertension and airflow limitation in obese women
<p>Abstract</p> <p>Background</p> <p>Neutrophil elastase level/activity is elevated in a variety of diseases such as atherosclerosis, systolic hypertension and obstructive pulmonary disease. It is unknown whether obese individuals with prehypertension also have elevated neutrophil elastase, and if so, whether it has a deleterious effect on pulmonary function. Objectives: To determine neutrophil elastase levels in obese prehypertensive women and investigate correlations with pulmonary function tests.</p> <p>Methods</p> <p>Thirty obese prehypertensive women were compared with 30 obese normotensive subjects and 30 healthy controls. The study groups were matched for age. Measurements: The following were determined: body mass index, waist circumference, blood pressure, lipid profile, high sensitivity C-reactive protein, serum neutrophil elastase, and pulmonary function tests including forced expiratory volume in one second (FEV<sub>1</sub>), forced vital capacity (FVC) and FEV<sub>1</sub>/FVC ratio.</p> <p>Results</p> <p>Serum neutrophil elastase concentration was significantly higher in both prehypertensive (405.8 ± 111.6 ng/ml) and normotensive (336.5 ± 81.5 ng/ml) obese women than in control non-obese women (243.9 ± 23.9 ng/ml); the level was significantly higher in the prehypertensive than the normotensive obese women. FEV1, FVC and FEV1/FVC ratio in both prehypertensive and normotensive obese women were significantly lower than in normal controls, but there was no statistically significant difference between the prehypertensive and normotensive obese women. In prehypertensive obese women, there were significant positive correlations between neutrophil elastase and body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, high sensitivity C-reactive protein and negative correlations with high density lipoprotein cholesterol, FEV1, FVC and FEV1/FVC.</p> <p>Conclusion</p> <p>Neutrophil elastase concentration is elevated in obese prehypertensive women along with an increase in high sensitivity C-reactive protein which may account for dyslipidemia and airflow dysfunction in the present study population.</p
Maize Inbreds Exhibit High Levels of Copy Number Variation (CNV) and Presence/Absence Variation (PAV) in Genome Content
Following the domestication of maize over the past ∼10,000 years, breeders have exploited the extensive genetic diversity of this species to mold its phenotype to meet human needs. The extent of structural variation, including copy number variation (CNV) and presence/absence variation (PAV), which are thought to contribute to the extraordinary phenotypic diversity and plasticity of this important crop, have not been elucidated. Whole-genome, array-based, comparative genomic hybridization (CGH) revealed a level of structural diversity between the inbred lines B73 and Mo17 that is unprecedented among higher eukaryotes. A detailed analysis of altered segments of DNA conservatively estimates that there are several hundred CNV sequences among the two genotypes, as well as several thousand PAV sequences that are present in B73 but not Mo17. Haplotype-specific PAVs contain hundreds of single-copy, expressed genes that may contribute to heterosis and to the extraordinary phenotypic diversity of this important crop
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