2000-2003年广州地区耐甲氧西林金黄色葡萄球菌耐药变迁及治疗对策

目的了解广州地区12家医院临床分离的耐甲氧西林金黄色葡萄球菌(MRSA)的耐药现状及动态变化情况,为临床治疗提供对策。方法严格按NCCLS标准用K-B法对2000-2003年自广州地区12家医院临床分离出的1247株金黄色葡萄球菌进行微生物药物敏感性试验检测。结果1.2000-2003年每年的MRSA的检出率分别为50.8%(154/303)、65.0%(195/300)、61.1%(228/373)、70.8%(192/271),结果差异显著(P<0.001)。2.2000-2003年MRSA对受试的7种抗生素的敏感率分别为环丙沙星(C IP)22.1-40.0%、四环素(TET)35.1-50.3%、红霉素(ERY)12.0-18.9%、万古霉素(VAN)100.0%、克林霉素(CLI)45.8-68.2%、庆大霉素(GEN)20.2-40.1%、青霉素(PEN)0.0%,其中CLI、C IP、GEN的耐药性在四年间差异显著(P<0.001),而其他的几种抗生素均无差异(P>0.05),未发现耐万古霉素的MRSA。结论VAN是治疗MRSA感染的首选经验用药,为控制MRSA感染的发生,临床应合理使用抗生素。     

我院儿科门诊抗生素用药分析

目的:为了了解目前儿科门诊抗生素的使用情况,促进临床抗生素的合理使用,提供参考.方法:随机抽取2003年7月～9月门诊西药处方11703张,统计抗生素处方占处方总数的百分比,两种口服抗生素联合用药和两种注射抗生素联合用药方式,前10位两种注射抗生素联用品种以及前10位两种口服抗生素联用品种.结果:含有抗生素的处方占处方总数的64.75%,口服抗生素处方占含抗生素处方的34.99%,注射抗生素处方占含抗生素处方的65.01%.结论:抗生素使用率较高,剂量偏大,个别联合用药方式有的无理论根据,有的明显不合理,有的甚至属滥用.     

降钙素原(PCT)在脓毒症临床诊断治疗中作用的研究进展

 脓毒症是指机体对感染的反应失调而导致的危及生命的器官功能障碍,并可导致脓毒性休克(脓毒症合并出现严重的循环障碍和细胞代谢紊乱),其死亡风险较单纯脓毒症显著升高,已成为全球人类十大死因之一,且为重症监护室患者常见并发症和死亡原因。因此,对脓毒症的早期鉴别诊断、合理抗生素治疗是决定患者预后的关键。降钙素原(procalcitonin,PCT)是降钙素的前体物质,在健康人血中浓度很低。当全身性细菌感染时,血中PCT水平迅速升高,且其升高程度与疾病严重程度相关。这一特点使得PCT可作为脓毒症或脓毒性休克诊断的血清标志物之一,并较传统血清标志物(C反应蛋白等)灵敏度高、特异性好。而动态监测PCT水平可反映机体对抗生素治疗的敏感性,并进一步指导抗生素治疗的疗程。本文总结了PCT在早期诊断脓毒症和指导抗生素治疗中的临床应用价值。PCT可以作为早期诊断脓毒症的良好指标,并可用于评估患者病情严重程度、进一步指导抗生素治疗、减少抗生素耐药与缩短疗程。单一的PCT指标在检测准确性和应用范围上仍有一定局限,PCT与其他生物标志物组合作为更可靠的诊断和治疗指标是未来的发展前景。     

USA300 methicillin‐resistant Staphylococcus aureus in Norway

Moen AEF*, Tannæs TM, Leegaard TM. USA300 methicillin‐resistant Staphylococcus aureus (MRSA) in Norway. Community‐associated methicillin‐resistant S. aureus USA300 is known for its ability to disseminate and colonize and the clone has been detected globally. We studied the most populated area in Norway in search for the strain and for signs of endemic establishment. Strain typing techniques such as spa‐, SCCmec‐ and dru‐typing, pulsed‐field gel electrophoresis and detection of USA300 molecular markers, lukS/F‐PV and arcA, were performed. USA300 has been present in the study area since 2003 and has increased in incidence in parallel with the total MRSA incidence. Most USA300 isolates were found in the community, but isolates were also detected in health care institutions.     

Bacillus spp. as direct-fed microbial antibiotic alternatives to enhance growth,immunity, and gut health in poultry

The increasing occurrence of antibiotic-resistant bacteria combined with regulatory pressure and consumer demands for foods produced without antibiotics has caused the agricultural industry to restrict its practice of using antibiotic growth promoters (AGP) in food animals. The poultry industry is not immune to this trend, and has been actively seeking natural alternatives to AGP that will improve the health and growth performance of commercial poultry flocks. Bacillus probiotics have been gaining in popularity in recent years as an AGP alternative because of their health-promoting benefits and ability to survive the harsh manufacturing conditions of chicken feed production. This review provides an overview of several modes of action of some Bacillus direct-fed microbials as probiotics. Among the benefits of these direct-fed microbials are their production of naturally synthesized antimicrobial peptides, gut flora modulation to promote beneficial microbiota along the gastrointestinal tract, and various immunological and gut morphological alterations. The modes of action for increased performance are not well defined, and growth promotion is not equal across all Bacillus species or within strains. Appropriate screening and characterization of Bacillus isolates prior to commercialization are necessary to maximize poultry growth to meet the ultimate goal of eliminating AGP usage in animal husbandry.     

Phenotypic and genotypic characterization of enteroaggregative Escherichia coli isolates from pediatric population in Pakistan

Enteroaggregative Escherichia coli (EAEC) are a leading cause of diarrhea among children. The objective of this study was to define the frequency of EAEC among diarrheal children from flood‐affected areas as well as sporadic cases, determine multidrug resistance, and evaluation of virulence using an in vivo model of pathogenesis. Stool samples were collected from 225 diarrheal children from 2010 to 2011 from flood‐affected areas as well as from sporadic cases in Pakistan. Identified EAEC isolates were characterized by phylogrouping, antibiotic resistance patterns including the extended‐spectrum beta lactamase spectrum, single nucleotide polymorphism detection in gyrA and parC, and virulence potential using wax worm, G. mellonella. A total of 35 (12.5%) confirmed EAEC isolates were identified among 225 E. coli isolates. EAEC isolates displayed high resistance to tetracycline, ampicillin, and cefaclor. A total of 34.28% were ESBL positive. Single nucleotide polymorphism detection revealed 37.14% and 68.57% isolates were positive for SNPs in gyrA (A₆₆₀‐T₆₆₀) and parC (C₃₃₀‐T₃₃₀), respectively. Phylogrouping revealed that B2 phylogroup was more prevalent among all EAEC isolates tested followed by D, A, B1, and non‐typeable (NT). Infection of G. mellonella with EAEC showed that killing infective dose was 100% higher than E. coli DH5 alpha control. EAEC are prevalent among Pakistani children with diarrhea, they are highly resistant to antibiotics, and predominantly fall into B2 phylogroup. Epidemiologic surveillance of EAEC and other E. coli pathotypes is critical to assess not only the role of these pathogens in diarrheal disease but also to determine the extent of multidrug resistance among the population.     

超高效液相色谱-串联质谱测定尿中14种β-内酰胺类抗生素残留

目的 建立测定尿液中14种β-内酰胺类抗生素残留的超高效液相色谱-串联质谱分析方法。 方法 尿液经酶解后,Oasis PRiME HLB(200 mg,6 ml)固相萃取柱净化,采用Waters BEH C18色谱柱(2.1 mm×100 mm, 1.7 μm),0.01 mol/L乙酸铵的水-甲醇作为流动相进行梯度洗脱,电喷雾离子源电离,正离子扫描,多反应监测模式进行定性和定量分析。 结果 阿莫西林和头孢曲松的线性范围为10～1 000 ng/ml,其余12种β-内酰胺类抗生素为5～1 000 ng/ml,相关系数均大于0.99。阿莫西林和头孢曲松的定量限为10 ng/ml,其余的方法定量下限为5 ng/ml,检出限为0.5～2.9 ng/ml,3个加标水平下的回收率为79.8%～97.9%,相对标准偏差为2.1%～11.9%。 结论 该方法操作简便、具有较高的灵敏度、特异度和精确性,适用于尿中痕量14种β-内酰胺类抗生素残留量的测定。