A new look at anti-Helicobacter pylori therapy

With the rising prevalence of antimicrobial resistance,the treatment success of standard triple therapy has recently declined to unacceptable levels (i.e.,80% or less) in most countries.Therefore,several treatment regimens have emerged to cure Helicobacter pylori (H.pylori) infection.Novel first-line anti-H.pylori therapies in 2011 include sequential therapy,concomitant quadruple therapy,hybrid (dual-concomitant) therapy and bismuth-containing quadruple therapy.After the failure of standard triple therapy,a bismuth-containing quadruple therapy comprising a proton pump inhibitor (PPI),bismuth,tetracycline and metronidazole can be employed as rescue treatment.Recently,triple therapy combining a PPI,levofloxacin and amoxicillin has been proposed as an alternative to the standard rescue therapy.This salvage regimen can achieve a higher eradication rate than bismuth-containing quadruple therapy in some regions and has less adverse effects.The best second-line therapy for patients who fail to eradicate H.pylori with first-line therapies containing clarithromycin,amoxicillin and metronidazole is unclear.However,a levofloxacin-based triple therapy is an accepted rescue treatment.Most guidelines suggest that patients requiring third-line therapy should be referred to a medical center and treated according to the antibiotic susceptibility test.Nonetheless,an empirical therapy (such as levofloxacin-based or furazolidone-based therapies) can be employed to terminate H.pylori infection if antimicrobial sensitivity data are unavailable.

Levofloxacin/amoxicillin-based schemes vs quadruple therapy for Helicobacter pylori eradication in second-line

Worldwide prevalence of Helicobacter pylori(H.pylori) infection is approximately 50%,with the highest being in developing countries.We compared cure rates and tolerability(SE) of second-line anti-H.pylori levofloxacin/amoxicillin(LA)-based triple regimens vs standard quadruple therapy(QT).An English language literature search was performed up to October 2010.A meta-analysis was performed including randomized clinical trials comparing 7-or 10-d LA with 7-d QT.In total,10 articles and four abstracts were identified.Overall eradication rate in LA was 76.5%(95% CI:64.4%-97.6%).When only 7-d regimens were included,cure rate was 70.6%(95% CI:40.2%-99.1%),whereas for 10-d combinations,cure rate was significantly higher(88.7%;95% CI:56.1%-109.9%;P < 0.05).Main eradication rate for QT was 67.4%(95% CI:49.7%-67.9%).The 7-d LA and QT showed comparable efficacy [odds ratio(OR):1.09;95% CI:0.63-1.87],whereas the 10-d LA regimen was significantly more effective than QT(OR:5.05;95% CI:2.74-9.31;P < 0.001;I 2 = 75%).No differences were reported in QT eradication rates among Asian and European studies,whereas LA regimens were more effective in European populations(78.3% vs 67.7%;P = 0.05).Incidence of SE was lower in LA therapy than QT(OR:0.39;95% CI:0.18-0.85;P = 0.02).A higher rate of side effects was reported in Asian patients who received QT.Our findings support the use of 10-d LA as a simple second-line treatment for H.pylori eradication with an excellent eradication rate and tolerability.The optimal second-line alternative scheme might differ among countries depending on quinolone resistance.

Intensification of levofloxacin sono-degradation in a US/H_2O_2 system with Fe_3O_4 magnetic nanoparticles

Fe3O4 magnetic nanoparticles(MNPs) were synthesised, characterised, and used as a peroxidase mimetic to accelerate levofloxacin sono-degradation in an ultrasound(US)/H2O2 system. The Fe3O4 MNPs were in nanometre scale with an average diameter of approximately 12 to 18 nm. The introduction of Fe3O4 MNPs increased levofloxacin sono-degradation in the US/H2O2 system. Experimental parameters, such as Fe3O4 MNP dose, initial solution p H, and H2O2 concentration, were investigated by a one-factor-at-a-time approach. The results showed that Fe3O4 MNPs enhanced levofloxacin removal in the p H range from 4.0 to 9.0. Levofloxacin removal ratio increased with Fe3O4 MNP dose up to 1.0 g·L-1and with H2O2 concentration until reaching the maximum. Moreover, three main intermediate compounds were identified by HPLC with electrospray ionisation tandem mass spectrometry, and a possible degradation pathway was proposed. This study suggests that combination of H2O2, Fe3O4 MNPs and US is a good way to improve the degradation efficiency of antibiotics.

In vitro Sensitivity of Three Bacterial Pathogens of Koi Carp （Cyprynus carpio L.） to Certain Antibiotics

Three gram negative bacteria isolated from infected koi carp, Cyprinus carpio L. and screened for sensitivity to thirty antibiotics by the Bauer disc diffusion method. Bacteria evaluated were Aeromonas hydrophila, Pseudomonas aeruginosa and Edwardseilla tarda. A. hydrophila was resistant to ampicilin, cephalothin, sulphatriad, cefpodoxime and cefoxitin. Highest sensitivity was recorded to Colistin methane sulphonate and Ceftriaxone. High resistance was observed for P. aeruginosa in Kanamysin, Cephalothin, Sulphatriad, Colistin methane sulphonate, Tobramysin, Nitro Furantoin, Cefpodoxime, Cefoxitin and Aztreonam. Highest sensitivity recorded with Moxifloxacin. High resistance was observed in Co-trimoxamole and higher sensitivity performed for E. tarda by Tetracyclin, Cephotaxime, Ciprofloxacin, Norfloxacin, Ofloxacin, Moxifloxacin, Gatifloxacin and Levofloxacin. Out of that highest sensitivity recorded with Moxifloxacin High sensitivity was recorded for Moxifloxacin, Ciprofloxacin, Gatifloxacin, Levofloxacin. By means of antibiotic sensitivity test highest resistance was recorded to P. aeruginosa （MAR index-0.3） and least resistant was recorded to E, tarda （MAR index- 0.033）.

Antimicrobial Susceptibilities of Salmonella spp. Isolated from Chicken Meat Samples

The aim of this study was to determine presence of Salmonella spp. in chicken meat samples collected from Ankara, Turkey and determine the susceptibility of the Salmonella isolates to some antimicrobial agents. For this purpose, 127 chicken samples were collected from local markets. Investigation of Salmonella was done according to horizontal method, the guidelines of the method recommended by International Standards Organization （ISO）. Antimicrobial susceptibilities of Salmonella spp. was performed with microdilution method according to the guidelines of CLSI M100-SI8. Ampicillin, gentamicin sulphate, ofloxacin, levofloxacin, ciprofloxacin, enrofloxacin, tetracycline, ceftriaxon, amoxicillin/clavulanic acid and trimethoprim/sulfamethoxazole were used in the study. Salmonella spp. was isolated from 5 （3.94%） of the 127 chicken meat samples. Although our findings are not within Turkish Food Codex （TFC） values, lower number of samples that involve Salmonella spp. indicates an improvement in the hygienic conditions in Turkey. Among 5 isolates, one isolate was sensitive to all antimicrobial agents tested. 2 isolates exhibited multidrug resistance. Successfully, all the isolates were sensitive to quinolones as a good result in spite of the reported reduced susceptibility from different regions of the world. However, this study should be improved with more chicken samples and Salmonella spp. isolate numbers to support these results.

结核杆菌对四种二线药物的敏感性试验

目的测定结核分枝杆菌对二线药物的敏感性,为结核病的防治提供理论依据。方法采用绝对浓度法的间接法测定结核分枝杆菌对卡那霉素(KM)、(左)氧氟沙星(OFLX)、环丙沙星(CFX)、对氨基水杨酸(PAS)四种药物的耐药性。结果 60株结核杆菌对单一药敏试验耐药率高低次序是:PAC(100%)、KM(39.3%)、CFX(18.3%)、OFLX(16.7%)。结论结核分枝杆菌对KM、OFLX、CFX、PAS的初始耐药率处于上升水平,必须进一步加强对耐药结核杆菌的监控。

Construction of universal calibration model for levofloxacin injections by fiber-optic transmittance-reflectance near-infrared spectroscopy

The general strategy and method of constructing universal calibration model for levofioxacin injections by near-infrared spectroscopy have been investigated and discussed. Firstly, a constant-temperature homogeneous liquid calibration model for levofloxacin hydrochloride injections with the same composition but different active principal ingredient （API） content was established as the basic unit for universal model. Then, samples of levofloxacin hydrochloride injections containing propylene glycol or levofloxacin lactate injections were added to develop a primary constant-temperature liquid universal model. Temperature- amended final universal model was established to apply to samples under different temperatures. The final model was built from 61 calibration samples and 77 validation samples. The value of the root mean square error of cross validation （RMSECV） and coefficient of determination （r2） of leave-one-out cross-validation （LOOCV） were 0.792 and 0.9993, respectively, the root mean square error of prediction （RMSEP） of test set validation （TSV） was 0.87, and the average relative deviation was 1.44%. According to the ICH guidelines, the universal calibration model was evaluated. Based on the experimental statistical results, the recommended number of calibration samples for a constant-temperature homogeneous liquid quantitative model was no less than 15.