盐酸莫西沙星治疗慢性阻塞性肺疾病急性加重期的疗效及安全性

目的探讨盐酸莫西沙星序贯疗法治疗慢性阻塞性肺疾病急性加重期的临床疗效及安全性。方法选取200例慢性阻塞性肺疾病急性加重期的患者,随机分为对照组和观察组,对照组静脉给予盐酸莫西沙星氯化钠注射液治疗,观察组采用莫西沙星序贯疗法进行治疗,前5日静脉给予盐酸莫西沙星氯化钠注射液,病情好转后口服盐酸莫西沙星片,考察两组治疗前、后肺功能指标参数及血液中IL-8、TNF-α水平,比较两组的临床疗效和安全性。结果经治疗后,观察组临床总有效率为94.0%,与对照组的95.0%比较,差异无统计学意义(χ~2=0.0481,P0.05);两组患者的肺功能指标参数与治疗前比较,差异有统计学意义(P0.05),但观察组改善程度与对照组比较,差异有统计学意义(P0.05);两组患者血液中IL-8、TNF-α水平与治疗前比较,差异有统计学意义(P0.05),观察组与对照组比较,差异无统计学意义(P0.05);观察组不良反应发生率8.0%与对照组17.0%比较,差异有统计学意义(χ~2=1.8514,P0.05)。结论采用序贯疗法治疗慢性阻塞性肺疾病,有安全、有效等优点,具有较大的临床推广意义。     

肺炎链球菌致老年患者社区获得性肺炎的危险因素与临床耐药性

目的了解肺炎链球菌致老年患者社区获得性肺炎的危险因素与耐药特征,为临床合理使用抗菌药物,有效预防和控制感染提供依据。方法收集2011年1月至2014年12月金华市第二医院老年科住院患者下呼吸道标本中分离的肺炎链球菌253株,均经全自动微生物鉴定仪鉴定,药敏试验采用纸片扩散法(K-B),结果按美国临床和实验室标准协会(CLSI)标准判读,采用WHONET 5.6软件进行耐药性分析。结果调查显示感染的最危险因素是患者年龄≥60岁,主要标本来源于痰液(75.5%);药敏试验表明肺炎链球菌对克林霉素、红霉素、四环素和复方新诺明的耐药率最高,分别为90.1%、86.2%、81.4%和76.7%,而对阿莫西林、万古霉素、莫西沙星、替考拉宁和利奈唑胺的耐药率2.0%。结论肺炎链球菌是引发本院老年患者社区获得性肺炎的主要致病菌,主要检出于痰标本,其耐药情况较为严重,表现出多药耐药,临床必须加强对肺炎链球菌的耐药性监测,阿莫西林、万古霉素、莫西沙星、替考拉宁和利奈唑胺可作为治疗该菌感染的首选药物。     

莫西沙星药物临床应用及研究进展

本文主要对莫西沙星在治疗敏感菌炎症类疾病中的药理作用、临床应用以及研究进展做了进一步的总结分析和探讨。     

莫西沙星治疗老年支原体肺炎患者的临床疗效分析

目的:探讨莫西沙星治疗老年支原体肺炎患者的临床疗效。方法:收集我院收治的老年支原体肺炎患者80例,年龄60~79岁,随机分为对照组和实验组,每组各40例,两组患者均给予相应常规对症治疗,对照组患者给予红霉素治疗;实验组患者给予莫西沙星治疗。治疗结束后,比较两组患者的退热时间、住院时间、白细胞计数、C反应蛋白水平以及患者的临床总有效率。结果:与治疗前相比,两组患者治疗后的白细胞计数、C反应蛋白水平均显著下降(P0.05),且实验组患者退热时间以及住院时间较对照组显著缩短(P0.05),白细胞计数、C反应蛋白水平明显低于对照组(P0.05),而临床治疗总显著高于对照组(P0.05)。结论:莫西沙星能显著提高老年支原体肺炎患者的临床疗效。     

丹参注射液联合莫西沙星治疗老年慢阻肺急性发作患者的疗效分析

目的:探讨丹参注射液联合莫西沙星治疗老年慢性阻塞性肺病急性加重患者的疗效及对血清可溶性髓样细胞触发受体-1(STREM-1)、白细胞介素-6(IL-6)、中性粒细胞CD64(CD64)及炎症因子水平的影响。方法:选择2015年5月到2017年5月我院接诊的老年慢性阻塞性肺病急性加重患者95例作为研究对象,根据随机数表法分为观察组(n=49)和对照组(n=46)。对照组使用莫西沙星治疗,观察组采用丹参注射液联合莫西沙星治疗。比较两组治疗后的疗效、治疗前后血清STREM-1、IL-6、CD64、炎症因子[肿瘤坏死因子α(TNF-α)、C反应蛋白(CRP)、降钙素原(PCT)]水平、肺功能的变化及不良反应的发生情况。结果:治疗后,观察组临床疗效总有效率为95.92%,显著高于对照组(76.09%,P0.05);观察组患者血清STREM-1、IL-6、CD64、TNF-α、CRP及PCT水平均明显低于对照组(P0.05);观察组FEV1、FVC、FEV1%预测值均明显高于对照组(P0.05);两组患者不良反应总发生率分别6.12%、13.04%,组间比较差异无统计学意义(P0.05)。结论:丹参注射液联合莫西沙星治疗老年慢性阻塞性肺病患者的临床效果显著优于单用莫西沙星治疗,可能与其有效改善患者血清STREM-1、IL-6、CD64水平及炎症因子水平有关。     

宁泌泰胶囊联合盐酸莫西沙星治疗慢性前列腺炎患者的临床疗效及对血清TNF-α、IL-1β、M-CSF的影响

目的:探讨宁泌泰胶囊联合盐酸莫西沙星治疗慢性前列腺炎患者的临床疗效及对血清肿瘤坏死因子(TNF)-α、白介素(IL)-1β、巨噬细胞集落刺激因子(M-CSF)水平的影响。方法:选择2014年8月至2016年8月我院接诊的110例慢性前列腺炎患者,通过随机数表法分为观察组(n=55)和对照组(n=55)。对照组采用盐酸莫西沙星治疗,观察组联合宁泌泰胶囊治疗,均连续治疗2周。比较两组治疗前后慢性前列腺炎症状评分(NIH-CPSI)、前列腺液白细胞计数、血清TNF-α、IL-1β、M-CSF水平的变化及临床疗效。结果:治疗后,观察组临床疗效总有效率明显高于对照组(P0.05);两组NIH-CPSI评分、白细胞计数、血清TNF-α、IL-1β、M-CSF均较治疗前显著降低(P0.05),观察组以上指标均明显低于对照组(P0.05)。结论:宁泌泰胶囊联合盐酸莫西沙星治疗慢性前列腺炎的临床效果显著,可有效缓解临床症状,安全性高,其机制可能和降低血清TNF-α、IL-1β、M-CSF水平相关。     

哌拉西林舒巴坦联合莫西沙星治疗社区获得性肺炎的临床观察

目的:探讨哌拉西林舒巴坦与莫西沙星联用治疗社区获得性肺炎的临床效果。方法:随机选取2015年3月--2016年3月在我院呼吸科病区住院的90例社区获得性肺炎患者,并随机分为观察组(28例)、对照A组(31例)对照B组(31例)。观察组患者采用哌拉西林舒巴坦粉针3.75 g,bid,联合莫西沙星0.4 g,静脉注射,qd,对照A组患者则单用哌拉西林舒巴坦粉针3.75 g,静脉滴注,bid,对照B组患者采用单用莫西沙星0.4 g,静脉注射,qd,三组患者的治疗时间均为10 d。治疗结束后,比较两组患者的临床症状改善情况及不良反应的发生情况。结果:治疗10天后,观察组患者治疗后肺部浸润性阴影、肺部啰音、胃肠道情况及体温等均显著好转,观察组患者的临床治疗有效情况显著高于对照A组(100%vs 87.09%,P0.05),对照B组的有效率也较A组提高(96.77%vs 87.09%,P0.05)。观察组总体治愈率显著高于对照A组(92.86%vs 51.61%),对照B组的总体治愈率显著高于对照A组(70.97%vs 51.61%),但观察组和对照B组之间并无显著性差异(p0.05)。观察组、对照A组、对照B组的细菌清除率分别为92.86%、74.19%、90.32%,观察组和对照B组的清除率显著高于对照A组;三组的不良反应发生率比较并无显著性差异(P0.05)。结论:哌拉西林舒巴坦联合莫西沙星治疗社区获得性肺炎的效果显著优于单用哌拉西林舒巴坦治疗的效果,稍优于单用莫西沙星的治疗效果,安全性较高。     

头孢哌酮舒巴坦联合莫西沙星治疗老年肺部感染的临床效果研究

目的:研究头孢哌酮舒巴坦联合莫西沙星治疗老年肺部感染的临床效果。方法:以2014年1月至2016年12月于我院就诊的200例老年肺部感染患者为研究对象,将其随机分为观察组与对照组,每组各100例。两组患者均采用叩背吸痰、化痰、吸氧、营养支持等常规治疗方案。对照组静脉滴注头孢哌酮/舒巴坦钠进行治疗,每次3.0 g,每12 h给药1次;观察组联合静脉滴注莫西沙星治疗,每次0.4 g,每天给药1次。两组患者疗程均为2周。观察和比较两组患者的临床疗效、退热时间、止咳时间、肺部啰音消散时间和肺CT病灶吸收时间,治疗前后的血清超敏C反应蛋白水平以及白细胞计数的变化。结果:观察组的治疗总有效率为97.00%(97/100),明显高于对照组[83.00%(83/100)](P0.05);观察组的退热时间、止咳时间、肺部啰音消散时间以及肺CT病灶吸收时间均明显低于对照组(P0.05);两组治疗后的血清超敏C反应蛋白水平以及白细胞计数均较治疗前明显降低,且观察组以上指标显著低于对照组(P0.05);两组患者的不良反应发生率比较无明显差异(P0.05)。结论:头孢哌酮舒巴坦联合莫西沙星治疗老年肺部感染的临床效果明显优于单纯给予头孢哌酮舒巴坦治疗,不仅可以有效改善患者的临床症状、控制炎症,且具有较高的安全性。     

莫西沙星治疗78 例伤寒的临床疗效观察

目的:探讨莫西沙星在伤寒治疗中的临床意义。方法:将我院2008年6月至2010年6月期间78例确诊的伤寒患者随机分为治疗组(39例)和对照组(39例),治疗组给予莫西沙星,对照组给予盐酸左氧氟沙星,均静脉滴注,每日1次,体温正常后7 d停药。结果:治疗组痊愈率94.8%,总有效率100%;对照组痊愈率92.3%,总有效率100%,两组痊愈率差异无统计学意义(P<0.05);治疗组开始退热和体温降至正常的时间均较对照组缩短,差异有显著意义(P<0.05)。治疗组不良反应发生率明显低于对照组(P<0.05)。结论:莫西沙星在伤寒治疗中具有疗效确切、无复发、副作用少等特点,在治疗非耐药和耐药伤寒中有重要作用,有较好的临床应用前景。     

阿夫唑嗪联合盐酸莫西沙星治疗慢性前列腺炎的疗效及对血清TNF-α、IL-1β、PSP、M-CSF水平的影响

目的:探讨阿夫唑嗪联合盐酸莫西沙星治疗慢性前列腺炎的疗效及对血清肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、胰石蛋白(PSP)、巨噬细胞集落刺激因子(M-CSF)水平的影响。方法:选择2014年12月~2016年12月于我院就诊的98例慢性前列腺炎患者,按不同治疗方式分为对组与研究组,每组49例。对照组接受盐酸莫西沙星治疗,研究组基于对照组加以阿夫唑嗪治疗。观察并比较两组的临床疗效,治疗前后血清TNF-α、IL-1β、PSP、M-CSF水平、慢性前列腺炎症状指数评分(NIH-CPSI)的变化及不良反应的发生情况。结果:治疗后,研究组总有效率为95.91%,显著高于对照组(77.55%,P0.05)。两组治疗后血清TNF-α、IL-1β、PSP、M-CSF水平、NIH-CPSI评分均较治疗前显著下降,且研究组上述指标均明显低于对照组(P0.05)。两组不良反应的发生率比较差异无统计学意义(P0.05)。结论:阿夫唑嗪联合盐酸莫西沙星治疗慢性前列腺炎的疗效优于单用盐酸莫西沙星,可能与其显著降低血清TNF-α、IL-1β、PSP、M-CSF水平有关。     

The antibacterial agent,moxifloxacin inhibits virulence factors of <Emphasis Type="Italic">Candida albicans</Emphasis> through multitargeting

Fluoroquinolines are broad spectrum fourth generation antibiotics. Some of the Fluoroquinolines exhibit antifungal activity. We are reporting the potential mechanism of action of a fluoroquinoline antibiotic, moxifloxacin on the growth, morphogenesis and biofilm formation of the human pathogen Candida albicans. Moxifloxacin was found to be Candidacidal in nature. Moxifloxacin seems to inhibit the yeast to Hyphal morphogenesis by affecting signaling pathways. It arrested the cell cycle of C. albicans at S phase. Docking of moxifloxacin with predicted structure of C. albicans DNA Topoisomerase II suggests that moxifloxacin may bind and inhibit the activity of DNA Topoisomerase II in C. albicans. Moxifloxacin could be used as a dual purpose antibiotic for treating mixed infections caused by bacteria as well as C. albicans. In addition chances of developing moxifloxacin resistance in C. albicans are less considering the fact that moxifloxacin may target multiple steps in yeast to hyphal transition in C. albicans.     

Mycobacterium avium Possesses Extracellular DNA that Contributes to Biofilm Formation,Structural Integrity,and Tolerance to Antibiotics

Mycobacterium avium subsp. hominissuis is an opportunistic pathogen that is associated with biofilm-related infections of the respiratory tract and is difficult to treat. In recent years, extracellular DNA (eDNA) has been found to be a major component of bacterial biofilms, including many pathogens involved in biofilm-associated infections. To date, eDNA has not been described as a component of mycobacterial biofilms. In this study, we identified and characterized eDNA in a high biofilm-producing strain of Mycobacterium avium subsp. hominissuis (MAH). In addition, we surveyed for presence of eDNA in various MAH strains and other nontuberculous mycobacteria. Biofilms of MAH A5 (high biofilm-producing strain) and MAH 104 (reference strain) were established at 22°C and 37°C on abiotic surfaces. Acellular biofilm matrix and supernatant from MAH A5 7 day-old biofilms both possess abundant eDNA, however very little eDNA was found in MAH 104 biofilms. A survey of MAH clinical isolates and other clinically relevant nontuberculous mycobacterial species revealed many species and strains that also produce eDNA. RAPD analysis demonstrated that eDNA resembles genomic DNA. Treatment with DNase I reduced the biomass of MAH A5 biofilms when added upon biofilm formation or to an already established biofilm both on abiotic surfaces and on top of human pharyngeal epithelial cells. Furthermore, co-treatment of an established biofilm with DNase 1 and either moxifloxacin or clarithromycin significantly increased the susceptibility of the bacteria within the biofilm to these clinically used antimicrobials. Collectively, our results describe an additional matrix component of mycobacterial biofilms and a potential new target to help treat biofilm-associated nontuberculous mycobacterial infections.     

Serum bactericidal activities of moxifloxacin and levofloxacin against aerobic and anaerobic intra-abdominal pathogens

We studied the serum bactericidal activity (SBA) of moxifloxacin and levofloxacin against common pathogens associated with complicated intra-abdominal infections. Ten healthy volunteers received a single dose of moxifloxacin (400 mg) and levofloxacin (750 mg) and serum samples were collected at 2, 4, 8, 12, and 24h after the dose of each drug. Bactericidal titers in serum over time were determined for aerobic gram-negative bacilli (Escherichia coli, Klebseilla pneumoniae, and Enterobacter cloacae) and anaerobic bacteria (Bacteroides fragilis, Bacteroides thetaiotaomicron, Prevotella bivia, and Finegoldia magna). Both fluoroquinolones provided rapid (2h) attainment and prolonged (24h) SBA (titers > or = 1:8) against each of the aerobic bacilli studied. SBA was observed for at least 12h against B. fragilis strains with MICs < or = 2 microg/ml to moxifloxacin and < or = 4 microg/ml to levofloxacin. Prolonged (12h) SBA (titers > or = 1:2) was also observed against isolates of B. thetaiotaomicron, P. bivia, and F. magna with moxifloxacin < or = MICs 2 microg/ml.     

Effect of moxifloxacin on survival,lipid peroxidation and inflammation in immunosuppressed rats with soft tissue infection caused by Stenotrophomonas maltophilia

In order to investigate the effect of moxifloxacin on survival, lipid peroxidation and inflammation in immunosuppressed rats with soft tissue infection caused by Stenotrophomonas maltophilia, 144 white male Wistar rats were randomized into six groups: Groups A and B received saline or moxifloxacin once per day, respectively; Groups C and D received saline or moxifloxacin twice per day, respectively, and Groups E and F received saline or moxifloxacin three times per day, respectively. Blood samples were taken at 6 and 30 hr after administration of S. maltophilia. Malonodialdehyde (MDA), WBC counts, bacterial tissue overgrowth, serum concentrations of moxifloxacin and survival were assessed. Survival analysis proved that treatment with moxifloxacin every 8 hr was accompanied by longer survival than occurred in any other group. Tissue cultures 30 hr after bacterial challenge showed considerably less bacterial overgrowth in the spleens and lungs of moxifloxacin‐treated than in saline‐treated animals, but not in their livers. At 6 hr there were no statistically significant differences between groups. However, at 30 hr, MDA concentrations were significantly greater (P = 0.044) and WBC counts significantly lower (P = 0.026) in group D than in group C. No statistically significant variations were observed between the other groups. Moxifloxacin possibly stimulates lipid peroxidation and enhances phagocytosis, as indicated by MDA production and survival prolongation, without being toxic, as indicated by WBC count. Therefore, under the appropriate conditions, moxifloxacin has a place in treatment of infections in immunosuppressed patients and of infections caused by S. maltophilia.     

Optimization of tuberculosis complex chemotherapy with the use of moxifloxacin]

It was shown in vitro that moxifloxacin by its activity against Mycobacterium tuberculosis (susceptible and resistant to the main antituberculosis agents) was highly superior to lomefloxacin (by 2 to 4 times by the MIC and by 4 times by the MBC). In murine lung tissue culture the highest effect was observed with the use of moxifloxacin in combination with isoniazid and pirazinamide. The efficacy of the regimens with the use of moxifloxacin was estimated in the treatment of 152 patients with pulmonary tuberculosis diagnosticated for the first time. The use of moxifloxacin was shown to be most advantageous in complex therapy of patients with extended and progressive tuberculosis due to polyresistant Mycobacterium tuberculosis strains or patients with concomitant nonspecific inflammatory diseases of the respiratory tracts due to a great variety of grampositive and gramnegative organisms, acid fact bacteria, atypical bacteria and a great variety of anaerobes. The tolerance of the treatment regimens with the use of moxifloxacin was mainly satisfactory.     

Prevalence of Escherichia coli strains resistance to antibiotics in wound infections and raw milk

Antibiotic-resistant Escherichia coli strains including extended-spectrum β-lactamase (ESBL) isolates are globally widespread in medical, food, and environmental sources. Some of these strains are considered the most pathogenic bacteria in humans. The present work examined the predominance of antibiotic resistance in E. coli strains in wound infections comparing with E. coli strains isolated from a raw milk as a potential source of those strains. The wound infections included abdomen, anus, arm, back, buttock, chest, foot, hand, head, leg, lung, mouth, neck, penis, thigh, toe, and vagina infections. In total, 161 and 153 isolates identified as E. coli were obtained from wound infections and raw milk, respectively. A Vitek 2 system innovated by bioMérieux, France was applied to perform the identification and susceptibility tests. The E. coli isolates that have ability to produce ESBL were detected by an ESBL panel and NO45 card (bioMérieux). Over half of the E. coli were from abdomen, back, and buttock wound infections. More than 50%of the E. coli isolates obtained from wound infections were resistant to cefazolin, ampicillin, cefuroxime, ciprofloxacin, mezlocillin, moxifloxacin, piperacillin, and tetracycline; 70% of the isolates from wound infections and 0% of the isolates from raw milk were E. coli isolates produced ESBL. The data showed that the strains resistance to multi-antibiotic and produced ESBL are more widespread among wound infections than in raw milk.     

Reliability of quantitative real-time PCR for bacterial detection in cystic fibrosis airway specimens

The cystic fibrosis (CF) airway microbiome is complex; polymicrobial infections are common, and the presence of fastidious bacteria including anaerobes make culture-based diagnosis challenging. Quantitative real-time PCR (qPCR) offers a culture-independent method for bacterial quantification that may improve diagnosis of CF airway infections; however, the reliability of qPCR applied to CF airway specimens is unknown. We sought to determine the reliability of nine specific bacterial qPCR assays (total bacteria, three typical CF pathogens, and five anaerobes) applied to CF airway specimens. Airway and salivary specimens from clinically stable pediatric CF subjects were collected. Quantitative PCR assay repeatability was determined using triplicate reactions. Split-sample measurements were performed to measure variability introduced by DNA extraction. Results from qPCR were compared to standard microbial culture for Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, common pathogens in CF. We obtained 84 sputa, 47 oropharyngeal and 27 salivary specimens from 16 pediatric subjects with CF. Quantitative PCR detected bacterial DNA in over 97% of specimens. All qPCR assays were highly reproducible at quantities≥10(2) rRNA gene copies/reaction with coefficient of variation less than 20% for over 99% of samples. There was also excellent agreement between samples processed in duplicate. Anaerobic bacteria were highly prevalent and were detected in mean quantities similar to that of typical CF pathogens. Compared to a composite gold standard, qPCR and culture had variable sensitivities for detection of P. aeruginosa, S. aureus and H. influenzae from CF airway samples. By reliably quantifying fastidious airway bacteria, qPCR may improve our understanding of polymicrobial CF lung infections, progression of lung disease and ultimately improve antimicrobial treatments.     

Bacterial strain typing in the genomic era

Bacterial strain typing, or identifying bacteria at the strain level, is particularly important for diagnosis, treatment, and epidemiological surveillance of bacterial infections. This is especially the case for bacteria exhibiting high levels of antibiotic resistance or virulence, and those involved in nosocomial or pandemic infections. Strain typing also has applications in studying bacterial population dynamics. Over the last two decades, molecular methods have progressively replaced phenotypic assays to type bacterial strains. In this article, we review the current bacterial genotyping methods and classify them into three main categories: (1) DNA banding pattern-based methods, which classify bacteria according to the size of fragments generated by amplification and/or enzymatic digestion of genomic DNA, (2) DNA sequencing-based methods, which study the polymorphism of DNA sequences, and (3) DNA hybridization-based methods using nucleotidic probes. We described and compared the applications of genotyping methods to the study of bacterial strain diversity. We also discussed the selection of appropriate genotyping methods and the challenges of bacterial strain typing, described the current trends of genotyping methods, and investigated the progresses allowed by the availability of genomic sequences.     

皮肤软组织感染病原菌分布及耐药性分析

目的 调查皮肤软组织感染病原菌的种类及耐药性,为临床合理使用抗菌药物提供科学依据.方法 利用WHONET 5.6对2009年1月至2011年12月皮肤软组织感染患者脓液或分泌物细菌培养及药敏试验结果进行回顾性分析.结果 共分离菌株444株,金黄色葡萄球菌(SAU)分离率居第1位,171株占38.5％;表皮葡萄球菌居第2位,54株占12.2％;铜绿假单胞菌第3位,43株占9.7％;头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、阿米卡星、亚胺培南和美罗培南对革兰阴性杆菌有较好的抗菌活性(耐药率≤3.3％);金黄色葡萄球菌对青霉素和红霉素的耐药率为93.6％和65.0％,对呋喃妥因、利奈唑胺、利福平、莫西沙星和左旋氧氟沙星耐药率为0％、0％、1.4％、2.2％和9.3％,未检出万古霉素耐药株;耐甲氧西林金黄色葡萄球菌(MRSA)检出率25.7％ (44/171);MRSA和甲氧西林敏感金黄色葡萄球菌(MSSA)对氨苄西林/舒巴坦、利福平、莫西沙星三种药物的敏感性差异有统计学意义.结论 引起皮肤软组织感染病原菌以阳性球菌尤其是金黄色葡萄球菌为主,临床上应尽量根据药敏试验结果选用抗生素,合理用药.     

Evaluation of Trimethoprim/Sulfamethoxazole (SXT), Minocycline,Tigecycline, Moxifloxacin,and Ceftazidime Alone and in Combinations for SXT-Susceptible and SXT-Resistant Stenotrophomonas maltophilia by In Vitro Time-Kill Experiments

Background

The optimal therapy for infections caused by Stenotrophomonas maltophilia (S. maltophilia) has not yet been established. The objective of our study was to evaluate the efficacy of trimethoprim/sulfamethoxazole (SXT), minocycline, tigecycline, moxifloxacin, levofloxacin, ticarcillin-clavulanate, polymyxin E, chloramphenicol, and ceftazidime against clinical isolated S. maltophilia strains by susceptibility testing and carried out time-kill experiments in potential antimicrobials.

Methods

The agar dilution method was used to test susceptibility of nine candidate antimicrobials, and time-killing experiments were carried out to evaluate the efficacy of SXT, minocycline, tigecycline, moxifloxacin, levofloxacin, and ceftazidime both alone and in combinations at clinically relevant antimicrobial concentrations.

Results

The susceptibility to SXT, minocycline, tigecycline, moxifloxacin, levofloxacin, ticarcillin-clavulanate, chloramphenicol, polymyxin E, and ceftazidime were 93.8%, 95.0%, 83.8%, 80.0%, 76.3%, 76.3%, 37.5%, 22.5%, and 20.0% against 80 clinical consecutively isolated strains, respectively. Minocycline and tigecycline showed consistent active against 22 SXT-resistant strains. However, resistance rates were high in the remaining antimicrobial agents against SXT-resistant strains. In time-kill experiments, there were no synergisms in most drug combinations in time-kill experiments. SXT plus moxifloxacin displayed synergism when strains with low moxifloxacin MICs. Moxifloxacin plus Minocycline and moxifloxacin plus tigecycline displayed synergism in few strains. No antagonisms were found in these combinations. Overall, compared with single drug, the drug combinations demonstrated lower bacterial concentrations. Some combinations showed bactericidal activity.

Conclusions

In S. maltophilia infections, susceptibility testing suggests that minocycline and SXT may be considered first-line therapeutic choices while tigecycline, moxifloxacin, levofloxacin, and ticarcillin-clavulanate may serve as second-line choices. Ceftazidime, colistin, and chloramphenicol show poor active against S. maltophilia. However, monotherapy is inadequate in infection management, especially in case of immunocompromised patients. Combination therapy, especially SXT plus moxifloxacin, may benefit than monotherapy in inhibiting or killing S. maltophilia.