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1.
Travis Korosh Kelsey D. Jordan Ja‐Shin Wu Nigel Yarlett Rita K. Upmacis 《The Journal of eukaryotic microbiology》2016,63(2):153-161
Trichomonas vaginalis is a sexually transmitted parasite and, while it is often asymptomatic in males, the parasite is associated with disease in both sexes. Metronidazole is an effective treatment for trichomoniasis, but resistant strains have evolved and, thus, it has become necessary to investigate other possible therapies. In this study, we examined the effects of native and oxidized forms of the sodium salts of eicosapentaenoic, docosahexaenoic, and arachidonic acids on T. vaginalis activity. Eicosapentaenoic acid was the most toxic with 190 and 380 μM causing approximately 90% cell death in Casu2 and ATCC 50142 strains, respectively. In contrast, oxidized eicosapentaenoic acid was the least toxic, requiring > 3 mM to inhibit activity, while low levels (10 μM) were associated with increased parasite density. Mass spectrometric analysis of oxidized eicosapentaenoic acid revealed C20 products containing one to six additional oxygen atoms and various degrees of bond saturation. These results indicate that eicosapentaenoic acid has different effects on T. vaginalis survival, depending on whether it is present in the native or oxidized form. A better understanding of lipid metabolism in T. vaginalis may facilitate the design of synthetic fatty acids that are effective for the treatment of metronidazole‐resistant T. vaginalis. 相似文献
2.
JANELLE M. WRIGHT RICHARD I. WEBB PETER O'DONOGHUE PETER UPCROFT JACQUELINE A. UPCROFT 《The Journal of eukaryotic microbiology》2010,57(2):171-176
ABSTRACT. Trichomonas vaginalis is the most common sexually transmitted protozoan in the world and its resistance to metronidazole is increasing. The purpose of this study was to demonstrate that clinical metronidazole resistance in T. vaginalis does not occur via the same mechanism as laboratory‐induced metronidazole resistance—that is, via hydrogenosome down sizing. Ultrathin sections of this parasite were examined using transmission electron microscopy and the size and area of the cell and hydrogenosomes were compared between drug‐resistant laboratory lines and clinically resistant isolates. Clinical metronidazole‐resistant T. vaginalis had similar‐sized hydrogenosomes as a metronidazole‐sensitive isolate. Inducing metronidazole resistance in both of these isolates caused down sizing of hydrogenosomes. Inducing toyocamycin resistance did not cause any ultrastructural changes to the cell or to the hydrogenosome. No correlation between hydrogenosome number and the drug‐resistant status of T. vaginalis isolates and lines was observed. This report demonstrates that clinical metronidazole resistance is not associated with down‐sized hydrogenosomes, thus indicating that an alternative resistance mechanism is used by T. vaginalis. 相似文献
3.
David Leitsch Brian D. Janssen Daniel Kolarich Patricia J. Johnson Michael Duchêne 《Molecular microbiology》2014,91(1):198-208
The enzyme flavin reductase 1 (FR1) from Trichomonas vaginalis, formerly known as NADPH oxidase, was isolated and identified. Flavin reductase is part of the antioxidative defence in T. vaginalis and indirectly reduces molecular oxygen to hydrogen peroxide via free flavins. Importantly, a reduced or absent flavin reductase activity has been reported in metronidazole‐resistant T. vaginalis, resulting in elevated intracellular oxygen levels and futile cycling of metronidazole. Interestingly, FR1 has no close homologue in any other sequenced genome, but seven full‐length and three truncated isoforms exist in the T. vaginalis genome. However, out of these, only FR1 has an affinity for flavins, i.e. FMN, FAD and riboflavin, which is high enough to be of physiological relevance. Although there are no relevant changes in the gene sequence or any alterations of the predicted FR1‐mRNA structure in any of the strains studied, FR1 is not expressed in highly metronidazole‐resistant strains. Transfection of a metronidazole‐resistant clinical isolate (B7268), which does not express any detectable amounts of FR, with a plasmid bearing a functional FR1 gene nearly completely restored metronidazole sensitivity. Our results indicate that FR1 has a significant role in the emergence of metronidazole resistance in T. vaginalis. 相似文献
4.
Concordance between genetic relatedness and phenotypic similarities of Trichomonas vaginalis strains
Vladimír Hampl Štěpánka Vaňáčová Jaroslav Kulda Jaroslav Flegr 《BMC evolutionary biology》2001,1(1):11-10
Background
Despite the medical importance of trichomoniasis, little is known about the genetic relatedness of Trichomonas vaginalis strains with similar biological characteristics. Furthermore, the distribution of endobionts such as mycoplasmas or Trichomonas vaginalis virus (TVV) in the T. vaginalis metapopulation is poorly characterised. 相似文献5.
Twelve metronidazole-resistant and twelve metronidazole-susceptible strains ofTrichomonas vaginalis were tested for the presence of dsRNA. Three resistant and five susceptible strains were found to contain dsRNA which indicated
that metronidazole resistance does not correlate with the absence of dsRNA. Electron microscopy showed the homogenates of
all dsRNA -positive strains to contain virus-like particles 32 –38 nm in diameter, while no such particles were found in the
dsRNA-negative strains. A mutual relationship between the dsRNA and virus-like particles seems to exist.
After this paper had been accepted for publication the occurrence of virus-like particles in dsRNA-positive trichomonads was
reported by others (Wang A.L., Wang C.C.: The double stranded RNA inTrichomonas vaginalis may originate from virus-like particles.Proc. Nat. Acad. Sci. USA
83, 7956–7961, 1986). 相似文献
6.
Trichomonas vaginalis is an important human parasite of the urogenital tract. Jasmonates are a group of small lipids that are produced in plants and function as stress hormones. Naturally occurring methyl jasmonate (MJ) has been used to treat several types of cancer cells and it is cytotoxic to protistan parasites. It has been suggested that mitochondria are the target organelles of jasmonates. Here, we tested this drug against T. vaginalis. Although metronidazole has been the drug of choice for trichomoniasis, side effects from this treatment are common, and nausea and dizziness have been reported in up to 12% of patients. In addition, there has been increased recognition of resistance to metronidazole. We demonstrate here using flow cytometry, JC-1 and scanning and transmission electron microscopy that MJ induced the cell death of T. vaginalis parasites. Our results are discussed with previous findings published by others. 相似文献
7.
Ping Wang 《Plant biotechnology journal》2017,15(10):1322-1330
Development of resistance to the insecticidal toxins from Bacillus thuringiensis (Bt) in insects is the major threat to the continued success of transgenic Bt crops in agriculture. The fitness of Bt‐resistant insects on Bt and non‐Bt plants is a key parameter that determines the development of Bt resistance in insect populations. In this study, a comprehensive analysis of the fitness of Bt‐resistant Trichoplusia ni strains on Bt cotton leaves was conducted. The Bt‐resistant T. ni strains carried two genetically independent mechanisms of resistance to Bt toxins Cry1Ac and Cry2Ab. The effects of the two resistance mechanisms, individually and in combination, on the fitness of the T. ni strains on conventional non‐Bt cotton and on transgenic Bt cotton leaves expressing a single‐toxin Cry1Ac (Bollgard I) or two Bt toxins Cry1Ac and Cry2Ab (Bollgard II) were examined. The presence of Bt toxins in plants reduced the fitness of resistant insects, indicated by decreased net reproductive rate (R0) and intrinsic rate of increase (r). The reduction in fitness in resistant T. ni on Bollgard II leaves was greater than that on Bollgard I leaves. A 12.4‐day asynchrony of adult emergence between the susceptible T. ni grown on non‐Bt cotton leaves and the dual‐toxin‐resistant T. ni on Bollgard II leaves was observed. Therefore, multitoxin Bt plants not only reduce the probability for T. ni to develop resistance but also strongly reduce the fitness of resistant insects feeding on the plants. 相似文献
8.
Antibiotics resistance of Helicobacter pylori in children with upper gastrointestinal symptoms in Hangzhou,China
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Background
The decreasing eradication rate of Helicobacter pylori is mainly because of the progressive increase in its resistance to antibiotics. Studies on antimicrobial susceptibility of H. pylori in children are limited. This study aimed to investigate the resistance rates and patterns of H. pylori strains isolated from children.Materials and Methods
Gastric mucosa biopsy samples obtained from children who had undergone upper gastrointestinal endoscopy were cultured for H. pylori, and susceptibility to six antibiotics (clarithromycin, amoxicillin, gentamicin, furazolidone, metronidazole, and levofloxacin) was tested from 2012‐2014.Results
A total of 545 H. pylori strains were isolated from 1390 children recruited. The total resistance rates of H. pylori to clarithromycin, metronidazole, and levofloxacin were 20.6%, 68.8%, and 9.0%, respectively. No resistance to amoxicillin, gentamicin, and furazolidone was detected. 56.1% strains were single resistance, 19.6% were resistant to more than one antibiotic, 16.7% for double resistance, and 2.9% for triple resistance in 413 strains against any antibiotic. And the H. pylori resistance rate increased significantly from 2012‐2014. There was no significant difference in the resistance rates to clarithromycin, metronidazole, and levofloxacin between different gender, age groups, and patients with peptic ulcer diseases or nonulcer diseases.Conclusions
Antibiotic resistance was indicated in H. pylori strains isolated from children in Hangzhou, and it increased significantly during the 3 years. Our data strongly support current guidelines, which recommend antibiotic susceptibility tests prior to eradication therapy. 相似文献9.
Shahed Ardalan 《Experimental parasitology》2009,121(4):300-306
Trichomonas vaginalis is the cause of human trichomoniasis, the most common non-viral sexually transmitted disease worldwide. Although acquisition of iron by binding to host hemoglobin through distinct receptor(s) has been described, no specific heme- or hemoglobin-binding site has been reported in this parasite.To determine the presence of hemoglobin-binding protein(s), membrane proteins were subjected to hemoglobin-affinity chromatography. Eluted proteins were analysed by SDS-PAGE. Two protein bands of 48 and 63 kDa were detected. Competition assay with an excess amount of hemoglobin or hemin in hemoglobin-affinity chromatography could block the 63- and 48-kDa bands, respectively.Further analysis by mass spectrometry indicated that the 48- and 63-kDa proteins had identity with two T. vaginalis adhesins: AP51 and AP65, respectively. This study confirms the existence of multifunctional proteins in T. vaginalis, and suggested that AP51 and AP65, besides serving as adhesion molecules, could also act as heme- and hemoglobin-binding proteins. 相似文献
10.
Muriel Primon-Barros Graziela Vargas Rigo Amanda Piccoli Frasson Odelta dos Santos Lisiane Smiderle Silvana Almeida Alexandre José Macedo Tiana Tasca 《Memórias do Instituto Oswaldo Cruz》2015,110(7):877-883
Trichomonas vaginalis is a flagellate protozoan that parasitises the
urogenital human tract and causes trichomoniasis. During the infection, the
acquisition of nutrients, such as iron and purine and pyrimidine nucleosides, is
essential for the survival of the parasite. The enzymes for purinergic signalling,
including adenosine deaminase (ADA), which degrades adenosine to inosine, have been
characterised in T. vaginalis. In the evaluation of the ADA profile
in different T. vaginalis isolates treated with different iron
sources or with limited iron availability, a decrease in activity and an increase in
ADA gene expression after iron limitation by 2,2-bipyridyl and ferrozine chelators
were observed. This supported the hypothesis that iron can modulate the activity of
the enzymes involved in purinergic signalling. Under bovine serum limitation
conditions, no significant differences were observed. The results obtained in this
study allow for the assessment of important aspects of ADA and contribute to a better
understanding of the purinergic system in T. vaginalis and the role
of iron in establishing infection and parasite survival. 相似文献
11.
Background
Trichomonosis caused by Trichomonas vaginalis is the number one, non-viral sexually transmitted disease (STD) that affects more than 250 million people worldwide. Immunoglobulin A (IgA) has been implicated in resistance to mucosal infections by pathogens. No reports are available of IgA-reactive proteins and the role, if any, of this class of antibody in the control of this STD. The availability of an IgA monoclonal antibody (mAb) immunoreactive to trichomonads by whole cell (WC)-ELISA prompted us to characterize the IgA-reactive protein of T. vaginalis. 相似文献12.
Santo Landolfo Maria Giovanna Martinotti Pancrazio Martinetto Guido Forni Anna Maria Rabagliati 《Experimental parasitology》1981,52(3):312-318
The genetic control of resistance or susceptibility to Trichomonas vaginalis infection has been studied in mice of various strains infected by different routes. and female mice appear to be highly susceptible to intraperitoneal, subcutaneous, or intravaginal infection by T. vaginalis. By contrast, female mice on A background are resistant to T. vaginalis infection via any route. and C3H female mice display intermediate levels of resistance following intraperitoneal or subcutaneous inoculum, whereas they display high levels of resistance to intravaginal infection. On the other hand, susceptibility or resistance to T. vaginalis infection appears to be influenced by the host sex, since males inoculated subcutaneously display much higher levels of resistance than females of the same strain. Lastly, the age of the host seems to play an important role in determining the course of infection. Susceptibility to T. vaginalis decreases with age, being maximal at 3–4 weeks and minimal at 40–42 weeks. All together these results suggest that resistance or susceptibility to T. vaginalis infection is regulated by genes mapping outside the major histocompatibility complex (H-2 in the mouse), whose activity is modulated by the anatomic site first coming into contact with the protozoon, the sex, and the age of the recipient host. 相似文献
13.
Arianna Neri Giuseppina Mignogna Cecilia Fazio Alessandra Giorgi Maria Eugenia Schininà Paola Stefanelli 《BMC microbiology》2010,10(1):246
Background
Several mutations have been described as responsible for rifampicin resistance in Neisseria meningitidis. However, the intriguing question on why these strains are so rare remains open. The aim of this study was to investigate the protein content and to identify differential expression in specific proteins in two rifampicin resistant and one susceptible meningococci using two-dimensional electrophoresis (2-DE) combined with mass spectrometry. 相似文献14.
Tirello P Pozzebon A Cassanelli S Van Leeuwen T Duso C 《Experimental & applied acarology》2012,57(1):53-64
Problems with Tetranychus urticae are frequently reported in protected crops in Italy, particularly in roses where many introduced acaricides show a progressive
loss of effectiveness. We have conducted bioassays to assess the response of some Italian strains of T. urticae to a number of acaricides. These include compounds that were widespread and frequently used in the past, but also some recently
registered compounds. We investigated two T. urticae strains collected from rose growers where control failures were reported (SAN and PSE), together with a strain collected
from unsprayed vegetables (BOSA). Adult females of the rose strains (SAN and PSE) were resistant to tebufenpyrad (Resistant
Ratio—RR, RR50 = 48.4 and 163.6) and fenpyroximate (RR50 = 74.1 and 25.9) when compared to the susceptible BOSA strain. Lethal concentrations for these products were higher than
the registered field rate. The PSE strain proved to be highly resistant to abamectin (RR50 = 1,294.1). Variation in bifenazate susceptibility was detected amongst strains, but LC90 values of SAN and PSE were still in the range of the registered field rate. In egg bioassays, the SAN and PSE strains exhibited
high resistance levels to clofentezine (RR50 = 66,473 and 170,714), hexythiazox (RR50 = 70,244 and 159,493) and flufenoxuron (RR50 = 61.9 and 117.9). But the recently introduced ovi/larvicides etoxazole and spirodiclofen exhibited high activity on all
strains. The activity of detoxifying enzymes such as esterases, glutathione-S-transferases (GSTs) and cytochrome P450 monooxygenases
(MFOs) was determined in these strains as a preliminary attempt to identify potential resistance mechanisms. Enzymatic assays
showed that the rose strains exhibited 2.66 and 1.95-fold increased MFOs activity compared to the susceptible strain. Assays
for GSTs revealed that only the SAN strain exhibited a significantly higher activity. In contrast, only the PSE strain showed
a significant higher hydrolysis of 1-naphthyl acetate. 相似文献
15.
A. M. Vélez T. A. Spencer A. P. Alves A. L. B. Crespo B. D. Siegfried 《Journal of Applied Entomology》2014,138(5):315-325
Transgenic corn, Zea mays L., expressing the Bacillus thuringiensis Berliner (Bt) protein Cry1F has been registered for Spodoptera frugiperda (J. E. Smith) control since 2003 in the USA. Unexpected damage to Cry1F corn was reported in 2006 in Puerto Rico, and Cry1F resistance in S. frugiperda from Puerto Rico was documented. The study of fitness costs associated with insect resistance to Bt insecticidal proteins is important for understanding resistance evolution and for evaluating resistance management practices used to mitigate resistance to transgenic corn. Currently, no studies have addressed the fitness costs associated with Cry1F resistance in S. frugiperda. In this study, susceptible and resistant strains with similar genetic background and their reciprocal crosses were used to estimate Cry1F resistance fitness costs. Comparisons between life‐history traits and population growth rates of homozygous susceptible, heterozygous and homozygous resistant S. frugiperda were used to determine whether the resistance is associated with fitness costs. Major fitness costs were not apparent in either heterozygotes or homozygous resistant insects. However, there was a slight indication of hybrid vigour in the heterozygotes. Additionally, two lines in which the frequency of the resistant alleles was fixed at 0.5 were followed for seven generations, after which the frequency of resistant alleles slightly decreased in both lines. The lack of strong fitness costs associated with Cry1F resistance in S. frugiperda indicates that initial allele frequencies may be higher than expected in field populations and will tend to remain stable in field populations in the absence of selection pressure (e.g. Puerto Rico). 相似文献
16.
Fu‐Qiang Zhao Qi Li Guo‐Yue Chen Jun Li Hou‐Yang Kang Yi Wang Xing Fan Li‐Na Sha Yong‐Hong Zhou Hai‐Qin Zhang 《Journal of Phytopathology》2017,165(3):157-161
The Roegneria kamoji accession ZY 1007 was resistant to the mixed predominant races of Puccinia striiformis f.sp. tritici (Pst) in China based on field tests at adult‐plant stage. The seedling resistance evaluation of ZY 1007 showed that it was resistant to stripe rust physiological strains CYR29, CYR33 and PST‐V26, which were the predominant races of Pst in China. The female parent R. kamoji cv. Gansi No.1 (susceptible to Pst) was crossed with ZY 1007 (resistant to Pst). Parents, F1 and F2 populations were tested in a field inoculated with the mixed urediniospores. ZY 1007 and all the observed 11 F1 hybrid plants were resistant, while plants of Gansi No.1 were susceptible. Among the 221 F2 plants, 168 plants were resistant and 53 were susceptible, and the segregation of resistant and susceptible plants fits 3R:1S ratio (χ2 = 0.074, P > 0.75). It confirmed that the resistance of stripe rust in ZY 1007 was controlled by a single dominant gene and temporarily designated as YrK1007. 相似文献
17.
Molina-Infante J Pazos-Pacheco C Vinagre-Rodriguez G Perez-Gallardo B Dueñas-Sadornil C Hernandez-Alonso M Gonzalez-Garcia G Mateos-Rodriguez JM Fernandez-Bermejo M Gisbert JP 《Helicobacter》2012,17(4):269-276
Background: Using quadruple clarithromycin‐containing regimens for Helicobacter pylori eradication is controversial with high rates of macrolide resistance. Aim: To evaluate antibiotic resistance rates and the efficacy of empirical and tailored nonbismuth quadruple (concomitant) therapy in a setting with cure rates <80% for triple and sequential therapies. Methods: 209 consecutive naive H. pylori‐positive patients without susceptibility testing were empirically treated with 10‐day concomitant therapy (proton pump inhibitors (PPI), amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg; all drugs b.i.d.). Simultaneously, 89 patients with positive H. pylori culture were randomized to receive triple versus concomitant therapy for clarithromycin‐susceptible H. pylori, and sequential versus concomitant therapy for clarithromycin‐resistant strains. Eradication was confirmed with 13C‐urea breath test or histology 8 weeks after completion of treatment. Results: Per‐protocol (PP) and intention‐to‐treat eradication rates after empirical concomitant therapy without susceptibility testing were 89% (95%CI:84–93%) and 87% (83–92%). Antibiotic resistance rates were: clarithromycin, 20%; metronidazole, 34%; and both clarithromycin and metronidazole, 10%. Regarding clarithromycin‐susceptible H. pylori, concomitant therapy was significantly better than triple therapy by per protocol [92% (82–100%) vs 74% (58–91%), p = 0.05] and by intention to treat [92% (82–100%) vs 70% (57–90%), p = 0.02]. As for antibiotic‐resistant strains, eradication rates for concomitant and sequential therapies were 100% (5/5) vs 75% (3/4), for clarithromycin‐resistant/metronidazole‐susceptible strains and 75% (3/4) vs 60% (3/5) for dual‐resistant strains. Conclusions: Empirical 10‐day concomitant therapy achieves good eradication rates, close to 90%, in settings with multiresistant H. pylori strains. Tailored concomitant therapy is significantly superior to triple therapy for clarithromycin‐susceptible H. pylori and at least as effective as sequential therapy for resistant strains. 相似文献
18.
Bardhan K Bayerdörffer E Veldhuyzen Van Zanten SJ Lind T Mégraud F Delchier JC Hellblom M Stubberöd A Burman CF Gromark P Zeijlon L 《Helicobacter》2000,5(4):196-201
Background. Helicobacter pylori eradication with omeprazole, amoxycillin, and metronidazole is both effective and inexpensive. However, eradication rates with different dosages and dosing vary, and data on the impact of resistance are sparse. In this study, three different dosages of omeprazole, amoxycillin, and metronidazole were compared, and the influence of metronidazole resistance on eradication was assessed. Methods. Patients (n = 394) with a positive H. pylori screening test result and endoscopy‐proven duodenal ulcer in the past were enrolled into a multicenter study performed in four European countries and Canada. After baseline endoscopy, patients were randomly assigned to treatment for 1 week with either omeprazole, 20 mg twice daily, plus amoxycillin, 1,000 mg twice daily, plus metronidazole, 400 mg twice daily (low M); or omeprazole, 40 mg once daily, plus amoxycillin, 500 mg three times daily, plus metronidazole, 400 mg three times daily (medium M); or omeprazole, 20 mg twice daily, plus amoxycillin, 1,000 mg twice daily, plus metronidazole, 800 mg twice daily (high M). H. pylori status at entry was assessed by a 13C urea breath test and a culture. Eradication was defined as two negative 13C‐urea breath test results 4 and 8 weeks after therapy. Susceptibility testing using the agar dilution method was performed at entry and in patients with persistent infection after therapy. Results. The eradication rates, in terms of intention to treat (ITT) (population n = 379) (and 95% confidence interval [CI]) were as follows: low M 76% (68%, 84%), medium M 76% (68%, 84%), and high M 83% (75%, 89%). By per‐protocol analysis (population n = 348), the corresponding eradication rates were: low M 81%, medium M 80%, and high M 85%. No H. pylori strains were found to be resistant to amoxycillin. Prestudy resistance of H. pylori strains to metronidazole was found in 72 of 348 (21%) of the cultures at entry (range, 10%–39% in the five countries). The overall eradication rate in prestudy metronidazole‐susceptible strains was 232 of 266 (87%) and, for resistant strains, it was 41 of 70 (57%; p < .001). Within each group, the results were as follows (susceptible/resistant): low M, 85%/54%; medium M, 86%/50%; and high M, 90%/75%. There were no statistically significant differences among the treatment groups. 23 strains susceptible to metronidazole before treatment were recultured after therapy failed; 20 of these had now developed resistance. Conclusions. H. pylori eradication rates were similar (approximately 80%) with all three regimens. Metronidazole resistance reduced efficacy; increasing the dose of metronidazole appeared not to overcome the problem or significantly improve the outcome. Treatment failure was generally associated with either prestudy or acquired metronidazole resistance. These findings are of importance when attempting H. pylori eradication in communities with high levels of metronidazole resistance. 相似文献
19.
Hyun-Ouk Song 《The Korean journal of parasitology》2016,54(1):71-74
Trichomonas vaginalis is a flagellate protozoan parasite and commonly infected the lower genital tract in women and men. Iron is a known nutrient for growth of various pathogens, and also reported to be involved in establishment of trichomoniasis. However, the exact mechanism was not clarified. In this study, the author investigated whether the 120 kDa protein of T. vaginalis may be involved in pathogenicity of trichomonads. Antibodies against 120 kDa protein of T. vaginalis, which was identified as pyruvate:ferredoxin oxidoreductase (PFOR) by peptide analysis of MALDI-TOF-MS, were prepared in rabbits. Pretreatment of T. vaginalis with anti-120 kDa Ab decreased the proliferation and adherence to vaginal epithelial cells (MS74) of T. vaginalis. Subcutaneous tissue abscess in anti-120 kDa Ab-treated T. vaginalis-injected mice was smaller in size than that of untreated T. vaginalis-infected mice. Collectively, the 120 kDa protein expressed by iron may be involved in proliferation, adhesion to host cells, and abscess formation, thereby may influence on the pathogenicity of T. vaginalis. 相似文献
20.
Antimicrobial susceptibility of 25 Helicobacter pylori strains isolated from patients with acid peptic diseases were tested for in vitro sensitivity to commonly used antibiotics using disk-diffusion and E-test, methods. All strains tested were susceptible to
tetracycline by E-test, with the minimum inhibitory concentration (MIC) values being <0.125 μg/ml for all strains except for
6 (<0.023 μg/ml). However 1 strain was resistant by disk-diffusion method. One strain was resistant to clarithromycin both
by disk diffusion and E-test (MIC <48 μg/ml), and 1 strain was resistant only by disk diffusion. Only one strain was resistant
to amoxicillin by disk diffusion and E-test (MIC >256 μg/ml). For ciprofloxacin, three strains were resistant by disk diffusion
and two by E-test (MIC <32 μg/ml). Sixteen strains were resistant to metronidazole by disk diffusion and E-test (MIC ≥ 8 μg/ml),
and 1 was resistant only by E-test (MIC <48 μg/ml). Overall, 64% of the strains were resistant to metronidazole. The MIC for
metronidazole was also tested by agar-dilution method, and metronidazole resistant strains had an, MIC >8 μg/ml. The disk-diffusion
method showed excellent correlation with E-test results; there was 100% agreement for amoxicillin a other antibiotics showed
90% to 95% accuracy. Disk diffusion is cheaper than E-test (approximately 2.6 cents vs. US$2.60), is easy to perform, and
is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory. 相似文献