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21.
Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic
MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and
antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A
high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics,
i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol,
pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance
patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can
be utilized in mastitis treatment programmes and antimicrobials strategies in organized herds. 相似文献
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ABSTRACT: BACKGROUND: Traditional medicine (TM) occupies a special place in the management of diseases in Uganda. Not with standing the many people relying on TM, indigenous knowledge (IK) related to TM is getting steadily eroded. To slow down this loss it is necessary to document and conserve as much of the knowledge as possible. This study was conducted to document the IK relevant to traditional medicine in the districts of Mukono, Nakapiripirit, Kanungu and Pallisa, in Uganda. METHODS: An ethnobotanical survey was conducted between October 2008 and February 2009 using techniques of key informant interviews and household interviews. RESULTS: The common diseases and conditions in the four districts include malaria, cough, headache, diarrhea, abdominal pain, flu, backache and eye diseases. Respondents stated that when they fall sick they self medicate using plant medicines or consult western-trained medicine practitioners. Self medication using herbal medicines was reported mostly by respondents of Nakapiripirit and Mukono. Respondents have knowledge to treat 78 ailments using herbal medicines. 44 species, mentioned by three or more respondents have been prioritized. The most frequently used part in herbal medicines is the leaf, followed by the stem and root. People sometime use animal parts, soil, salt and water from a grass roof, in traditional medicines. Herbal medicines are stored for short periods of time in bottles. The knowledge to treat ailments is acquired from parents and grandparents. Respondents' age and tribe appears to have a significant influence on knowledge of herbal medicine, while gender does not. CONCLUSION: This survey has indicated that IK associated with TM stills exists and that TM is still important in Uganda because many people use it as a first line of health care when they fall sick. Age and tribe influence the level of IK associated with herbal medicine, but gender does not. 相似文献
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Glutamine synthetase in the phloem plays a major role in controlling proline production 总被引:16,自引:1,他引:15
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N Brugiere F Dubois AM Limami M Lelandais Y Roux RS Sangwan B Hirel 《The Plant cell》1999,11(10):1995-2012
To inhibit expression specifically in the phloem, a 274-bp fragment of a cDNA (Gln1-5) encoding cytosolic glutamine synthetase (GS1) from tobacco was placed in the antisense orientation downstream of the cytosolic Cu/Zn superoxide dismutase promoter of Nicotiana plumbaginifolia. After Agrobacterium-mediated transformation, two transgenic N. tabacum lines exhibiting reduced levels of GS1 mRNA and GS activity in midribs, stems, and roots were obtained. Immunogold labeling experiments allowed us to verify that the GS protein content was markedly decreased in the phloem companion cells of transformed plants. Moreover, a general decrease in proline content in the transgenic plants in comparison with wild-type tobacco was observed when plants were forced to assimilate large amounts of ammonium. In contrast, no major changes in the concentration of amino acids used for nitrogen transport were apparent. A (15)NH(4)(+)-labeling kinetic over a 48-hr period confirmed that in leaves of transgenic plants, the decrease in proline production was directly related to glutamine availability. After 2 weeks of salt treatment, the transgenic plants had a pronounced stress phenotype, consisting of wilting and bleaching in the older leaves. We conclude that GS in the phloem plays a major role in regulating proline production consistent with the function of proline as a nitrogen source and as a key metabolite synthesized in response to water stress. 相似文献
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Certain drugs and chemicals, such as chloroquine, chlorpromazine, and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), are bound to melanin and retained in pigment cells for long periods. This specific retention in pigmented tissues can cause adverse effects in the skin, eye, inner ear, and pigmented nerve cells of the substantia nigra of the brain. To date, all studies have been focused on eu- and neuromelanin. In the present study, we show that chloroquine, chlorpromazine, chlomipramine, paraquat, acridine orange, and nickel, which are bound to eumelanin, also bind to synthetic pheomelanin, but the binding to pheomelanin is lower. The binding varied with the cysteine content and pH, and the results indicate that the binding is complex and includes ionic interactions. In addition, we have shown that these substances also bind to synthetic thiourea-containing melanin, but to quite a low extent. We also present a microautoradiographic study on the binding of 14C-chloroquine to natural pheomelanin in vivo in yellow mice C57BL (Ay/a). Black (C57/BL) and albino (NMRI) mice were used as controls. The autoradiography demonstrated a pronounced uptake of chloroquine in the hair follicles and the dermal melanocytes in the ear of yellow mice, which was comparable to the corresponding accumulation of label in black mice. In the albino mouse, the uptake was lower and more homogeneously distributed in the skin. These results suggest that the toxicologi-cal risks of melanin-related adverse effects are applicable to persons with a high content of pheomelanin in the skin and hair. 相似文献
27.
SV40 large T antigen has been reported to be modified with several
different sugars including N-acetylglucosamine, galactose, and mannose. In
this report we have reexamined the glycosylation of T antigen and found
that while we could detect modification with N-acetylglucosamine, we could
not detect any other sugars on the protein. Surprisingly, even though
[3H]galactose could be metabolically incorporated into the protein,
analysis showed that all of the radioactivity in T antigen had been
converted to other species. The N-acetylglucosamine was demonstrated to be
linked to the protein in the form of O-linked N- acetylglucosamine, the
best characterized form of nuclear and cytoplasmic glycosylation in
mammalian systems. We have localized the major site of glycosylation to the
amino terminal portion of the molecule. Analysis of mutated T antigen where
serines 111/112 were substituted with alanine suggest that these residues
constitute a glycosylation site on the protein. These two serines fall
within a typical O-linked N-acetylglucosamine glycosylation site (PSS) and
are also known to be phosphorylated. Thus, it is likely that competition
between phosphorylation and glycosylation occurs at this site.
相似文献
28.
Siebrasse EA Reyes A Lim ES Zhao G Mkakosya RS Manary MJ Gordon JI Wang D 《Journal of virology》2012,86(19):10321-10326
We have discovered a novel polyomavirus present in multiple human stool samples. The virus was initially identified by shotgun pyrosequencing of DNA purified from virus-like particles isolated from a stool sample collected from a healthy child from Malawi. We subsequently sequenced the virus' 4,927-bp genome, which has been provisionally named MW polyomavirus (MWPyV). The virus has genomic features characteristic of the family Polyomaviridae but is highly divergent from other members of this family. It is predicted to encode the large T antigen and small T antigen early proteins and the VP1, VP2, and VP3 structural proteins. A real-time PCR assay was designed and used to screen 514 stool samples from children with diarrhea in St. Louis, MO; 12 specimens were positive for MWPyV. Comparison of the whole-genome sequences of the index Malawi case and one St. Louis case demonstrated that the two strains of MWPyV varied by 5.3% at the nucleotide level. The number of polyomaviruses found in the human body continues to grow, raising the question of how many more species have yet to be identified and what roles they play in humans with and without manifest disease. 相似文献
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Background
Modeling of transmembrane domains (TMDs) requires correct prediction of interfacial residues for in-silico modeling and membrane insertion studies. This implies the defining of a target sequence long enough to contain interfacial residues. However, too long sequences induce artifactual polymorphism: within tested modeling methods, the longer the target sequence, the more variable the secondary structure, as though the procedure were stopped before the end of the calculation (which may in fact be unreachable). Moreover, delimitation of these TMDs can produce variable results with sequence based two-dimensional prediction methods, especially for sequences showing polymorphism. To solve this problem, we developed a new modeling procedure using the PepLook method. We scanned the sequences by modeling peptides from the target sequence with a window of 19 residues.Results
Using sequences whose NMR-structures are already known (GpA, EphA1 and Erb2-HER2), we first determined that the hydrophobic to hydrophilic accessible surface area ratio (ASAr) was the best criterion for delimiting the TMD sequence. The length of the helical structure and the Impala method further supported the determination of the TMD limits. This method was applied to the IL-2Rβ and IL-2Rγ TMD sequences of Homo sapiens, Rattus norvegicus, Mus musculus and Bos taurus.Conclusions
We succeeded in reducing the variation in the TMD limits to only 2 residues and in gaining structural information. 相似文献30.
Over the past decade, there have been many reports suggesting the presence
of complex carbohydrates on nuclear and cytoplasmic proteins in mammalian
cells. Some of the most often cited of these reports deal with the
glycosylation of the high mobility group (HMG) proteins. These are
relatively abundant chromosomal proteins that are known to be associated
with nucleosomes and actively transcribed regions of chromatin. The
original report describing HMG protein glycosylation presented several
lines of evidence suggesting that these proteins are glycosylated,
including carbohydrate compositional analysis and periodic-acid Schiff
staining. We have attempted to repeat these observations with more highly
purified protein than was utilized in the original study. Using
carbohydrate compositional analysis performed by high pH anion exchange
chromatography coupled to pulsed-amperometric detection, we saw no evidence
for significant glycosylation of these proteins. In addition, we found no
evidence for the presence of O- GlcNAc, a well known form of nuclear
glycosylation. The HMG proteins did react with periodate, suggesting the
presence of a modification containing cis-diols on the protein. Several
tryptic peptides isolated from HMG 14 and 17 which retained the periodate
reactivity had in common lysine residues, suggesting a potential
modification of the straightepsilon-amino groups of lysines such as
nonenzymatic glycation. Western blot analysis of the HMG proteins using
anti-advanced glycation endproducts (AGE) antibodies confirmed the presence
of glycation products on the HMG proteins.
相似文献