Sampling and Pooling Methods for Capturing Herd Level Antibiotic Resistance in Swine Feces using qPCR and CFU Approaches

The aim of this article was to define the sampling level and method combination that captures antibiotic resistance at pig herd level utilizing qPCR antibiotic resistance gene quantification and culture-based quantification of antibiotic resistant coliform indicator bacteria. Fourteen qPCR assays for commonly detected antibiotic resistance genes were developed, and used to quantify antibiotic resistance genes in total DNA from swine fecal samples that were obtained using different sampling and pooling methods. In parallel, the number of antibiotic resistant coliform indicator bacteria was determined in the same swine fecal samples. The results showed that the qPCR assays were capable of detecting differences in antibiotic resistance levels in individual animals that the coliform bacteria colony forming units (CFU) could not. Also, the qPCR assays more accurately quantified antibiotic resistance genes when comparing individual sampling and pooling methods. qPCR on pooled samples was found to be a good representative for the general resistance level in a pig herd compared to the coliform CFU counts. It had significantly reduced relative standard deviations compared to coliform CFU counts in the same samples, and therefore differences in antibiotic resistance levels between samples were more readily detected. To our knowledge, this is the first study to describe sampling and pooling methods for qPCR quantification of antibiotic resistance genes in total DNA extracted from swine feces.     

Development of an accelerated method of determining the antibiotic sensitivity of Cl. perfringens type A]

An express method for determination of antibiotic sensitivity in the strains of Cl. perfringens of type A using Soviet dry nutrient media and antibiotics is proposed. The criteria for estimation of the level of the antibiotic sensitivity of the causative agent of gas gangrene in short periods on the basis of comparison of the data of the antibiotic agar diffusion procedure and the antibiotic MIC were worked out. Twelve antibiotics and 45 collection strains of Cl. perfringens of type A were used in the experiment. The antibiotic agar diffusion method with the use of the nutrient media, microbial load and cultivation conditions developed by the authors is recommended for tentative determination of the antibiotic sensitivity in Cl. perfringens of type A for 4 hours. The use of the agar diffusion method and determination of the antibiotic MIC provided complete estimation of tha antibiotic sensitivity of Cl. perfringens of type A within not more than 24 hours.     

青年人群抗生素知识掌握和使用行为及其影响因素的研究

目的:研究黑龙江省青年人群抗生素知识掌握和使用行为及其影响因素。方法:随机抽取黑龙江省16~44岁之间的青年人,采用问卷调查法进行定量性的横断面研究。结果:2630名受访者中,38.62%知道抗生素可治疗细菌感染但不可治疗病毒感染,30.59%是根据医生处方选择抗生素的,有52.09%的受访者不能按疗程使用抗生素。其中,女性、自觉健康状况较差的受访者抗生素知识掌握与使用行为相对较好。结论:青年人群正确的抗生素知识和规范的抗生素使用行为的比例较低,需要加强青年人群抗生素相关知识及规范应用的教育。     

Complications from antibiotic therapy]

Analysis of 302 side effects of antibiotic theraphy is presented. The side effects were studied comparatively as dependent on the antibiotic group. Dependence of the toxic and toxicoallergic reactions to the antibiotics on the antibiotic blood levels were noted. Previous sensitization resulted in more frequent and earlier side effects. The analysis and clinical observations showed that antibiotic therapy should take into account the results of the laboratory tests, i.e. examination of the kidney functional state, antibiotic levels in the blood and urine, tolerance of the drug by the patient.     

Antibiotics in surgical treatment of acute abscesses.

A four-way, double-blind, prospective trial of treatment of abscesses by incision, curettage, and primary closure with and without antibiotic cover (clindamycin injection before operation or capsules after operation, or both) was conducted. There was no appreciable difference in mean healing time between the patients given both the antibiotic injection and the antibiotic capsules and those given the injection and placebo capsules, whereas healing times in those given the placebo injection and antibiotic capsules or placebo only were appreciably longer. Four of the patients who were not given the antibiotic injection developed bacteraemia; one patient who was given the antibiotic injection also developed a bacteraemia, but this was caused by clindamycin-resistant bacteria. These results show that a single injection of an effective antibiotic before operation is sufficient to protect the patient against bacteraemia and permit optimum healing.     

耐药淋球菌相关核苷酸序列的克隆与初步分析*

为克隆淋球菌染色体耐药相关核苷酸序列,我们利用抑制性消减杂交技术构建耐药性淋球菌与标准参考菌株差异DNA消减库,从中筛选淋球菌耐药相关核苷酸序列。通过初步筛选,对克隆得到的DNA片段进行测序,经GenBank和淋球菌基因组序列库检索分析,发现5个未知新核苷酸序列。这些核苷酸序列可能与淋球菌染色体耐药性相关,将为研究淋球菌耐药性提供新的实验对象。     

含铜抗菌不锈钢的抗菌性能研究

对铁素体和奥氏体2种含铜抗菌不锈钢的抗菌性能进行了考察.采用覆膜法检测抗菌率,用透射电镜观察与铁素体抗菌不锈钢作用后的大肠埃希菌细胞形态.2种抗菌不锈钢材料对供试的 17 株常见菌,除产气肠杆菌外均显示较强的抗菌性能,抗菌谱广;铁素体和奥氏体对1×107 cfu/mL及以下浓度的大肠埃希菌在 24 h内杀灭率达到99%;铁素体和奥氏体分别在作用 3 h和 9 h时可将1×107 cfu/mL的大肠埃希菌全部杀灭;打磨次数和环境温度的变化不影响2种抗菌不锈钢的杀菌率;透射电镜结果显示,与抗菌不锈钢作用后的大肠埃希菌菌体结构松散,细胞壁和细胞膜破裂,有内容物漏出.铁素体和奥氏体抗菌不锈钢均具优良的抗菌性能,抗菌谱广,与其作用后的细菌菌体破裂,有内容物溶出,最终致菌死亡.     

Influence of the culture medium on the production of iturin A by Bacillus subtilis

The production of iturin A by Bacillus subtilis was studied with respect to the composition of the culture medium. Increasing phosphate concentrations did not modify the antibiotic yield. Fructose, sucrose and mannitol were better carbon sources than glucose for antibiotic production. The nature of the nitrogen source was an important factor in the production of antibiotic. Among the amino acids which are components of iturin A, L-asparagine was the best substrate for the biosynthesis of iturin A; L-glutamine and L-serine were rather poor substrates while L-proline and D-tyrosine gave no antibiotic. Ammonium salts permitted good synthesis of antibiotic but the addition of calcium ions to the culture medium inhibited the excretion of antibiotic from the cells.     

Production of the Antibiotic Phenazine-1-Carboxylic Acid by Fluorescent Pseudomonas Species in the Rhizosphere of Wheat

Pseudomonas fluorescens 2-79 and P. aureofaciens 30-84 produce the antibiotic phenazine-1-carboxylic acid and suppress take-all, an important root disease of wheat caused by Gaeumannomyces graminis var. tritici. To determine whether the antibiotic is produced in situ, wheat seeds were treated with strain 2-79 or 30-84 or with phenazine-nonproducing mutants or were left untreated and then were sown in natural or steamed soil in the field or growth chamber. The antibiotic was isolated only from roots of wheat colonized by strain 2-79 or 30-84 in both growth chamber and field studies. No antibiotic was recovered from the roots of seedlings grown from seeds treated with phenazine-nonproducing mutants or left untreated. In natural soils, comparable amounts of antibiotic (27 to 43 ng/g of root with adhering soil) were recovered from roots colonized by strain 2-79 whether or not the pathogen was present. Roots of plants grown in steamed soil yielded larger bacterial populations and more antibiotic than roots from natural soils. In steamed and natural soils, roots from which the antibiotic was recovered had significantly less disease than roots with no antibiotic, indicating that suppression of take-all is related directly to the presence of the antibiotic in the rhizosphere.     

鲍曼不动杆菌的临床分布及药物敏感性结果分析

目的了解鲍曼不动杆菌的临床分布及药物敏感性分析。方法收集2004年5月至2006年5月抚顺市中心医院住院及门诊患者的临床标本,从中分离鲍曼不动杆菌。质控菌株:大肠埃希菌ATCC 25922,铜绿假单胞菌ATCC 27853,采用美国BD公司生产的凤凰微生物鉴定/药敏分析仪,对62株鲍曼不动杆菌进行鉴定和药物敏感测定并分析其临床分布。结果62株鲍曼不动杆菌感染率高的有呼吸病房22例(35.5%),干部病房14例(22.6%),标本类型以痰为主52例(83.9%)。药敏监测该细菌对17种抗生素的耐药情况为亚胺培南、美洛培南、氨苄西林/舒巴坦、左氧氟沙星的敏感率较高,分别为100%、100%、75.8%、70.9%。有头孢唑林、氨苄西林、奥格门丁、氨曲南耐药率为90.3%、88.7%、80.6%、77.4%。结论鲍曼不动杆菌最有效的抗生素是亚胺培南、美洛培南,一旦临床发生感染,应及时调整和选用合理抗生素治疗,避免滥用抗生素,防止耐药菌株的产生,提高临床治愈率。     

一种利用基因表达变化检测、鉴别抗生素的新方法

本研究利用基因表达变化构建一个高通量检测筛选抗生素化合物的新方法。采用含luxCDABE报道子的质粒pCS26和pMS402为载体,构建大肠杆菌重组质粒、筛选铜绿假单胞菌以及沙门氏菌的随机启动子库,获得对抗生素有反应的启动子-报道子融合体,构成抗生素筛选体系。通过重复实验筛选出15个启动子-报道子融合体,它们对不同抗生素有不同的反应,通过这一系统可以检测样品中的抗生素,并初步判断与现有抗生素的异同。使用这种方法可以进行高通量筛选潜在的抗菌物质。     

两种抗生素对酸性磷酸酶部分理化性质的影响

研究两种抗生素间甲氧嘧啶和蒽诺沙星对酸性磷酸酶活性的影响,发现两种抗生素都对酶有抑制作用。利用双倒数作图法表明两种抗生素对酶的抑制作用为非竞争抑制,Dixon作图法求得Ki值分别为0.35和0.4 mmol/L。采用紫外差光谱和荧光光谱研究甲氧嘧啶和蒽诺沙星与酸性磷酸酶的相互作用,结果显示间甲氧嘧啶和蒽诺沙星使酶的紫外吸收增强,荧光强度减弱,其中蒽诺沙星使酶的荧光光谱产生红移。说明这两种抗生素对酶的构象有不同程度的影响。     

Kinetics of Streptomyces baarnensis growth and antibiotic synthesis in batch and dialysis cultures

The kinetics of biomass and antibiotic formation in batch and dialysis culture of Streptomyces baarnensis at various initial concentrations limiting the substrate growth (glucose) has been studied. The antibiotic substances were synthesized by actively growing culture, its concentration in the cultural media was maximum in the log-phase. In continuous dialysis culture on the background of biomass lianer growth in the course of time the constant antibiotic concentration in the media proportional to the glucose input concentration has been established. The inactivation (decomposition) of antibiotic was immediately initiated after discontinuation of substrate supply and followed first kinetics order. Observed features were used for construction of kinetical model of antibiotic biosynthesis. A conclusion has been made that the dialysis culture gives opportunity for more effective antibiotic synthesis as compared with the batch one.     

Comparative pharmacokinetics of erythromycin target cell-associated transport and intravenous administration in patients with pneumonia]

The method of cell-associated antibiotic therapy consists of extracorporal exposure of the autoblood formed elements to antibiotic solution followed by their reinfusion. Pharmacokinetics of erythromycin after its intravenous and cell-associated administration in patients with community-acquired pneumonia and the clinical efficacy of the method were evaluated. HPLC of the erythromycin pharmacokinetic pattern in 20 patients showed that after the antibiotic target transport the pharmacokinetic model changed from one-compartment to two-compartment one and the antibiotic maximum concentration and elimination rate were lower vs. the intravenous administration. It was also shown that the clinical efficacies of the erythromycin intravenous administration and target transport did not significantly differ, whereas after the cell-associated transport of the antibiotic the therapeutic effect was observed earlier and the side effects were less frequent.     

Structure of pentaene antibiotic lavendofuseomycin

By its UV spectrum lavendofuseomycin, a macrolide pentaene antibiotic, was referred to the subgroup of adeopentaenes with the spectral symmetrical patterns. The antibiotic contains a carbonyl, the end and 4 isolated double bonds and hemiketal ring. The molecule is lacking sugar. After the hydroantibiotic oxidation 2-methylhexadecane dicarboxylic and 4'-methyloctanoic acids were isolated. The antibiotic carbon skeleton was asserted on the basis of the mass spectral analysis of the products of the antibiotic complete reduction and the products of the antibiotic retroaldol cleavage. Determination of the position of the isolated double bonds, localization of chromophore, oxygen functions and the position of the amino group in the molecule resulted from investigation of the antibiotic azonolysis products.     

The Impact of WHO Essential Medicines Policies on Inappropriate Use of Antibiotics

Background

Inappropriate overuse of antibiotics contributes to antimicrobial resistance (AMR), yet policy implementation to reduce inappropriate antibiotic use is poor in low and middle-income countries.

Aims

To determine whether public sector inappropriate antibiotic use is lower in countries reporting implementation of selected essential medicines policies.

Materials and Methods

Results from independently conducted antibiotic use surveys in countries that did, and did not report implementation of policies to reduce inappropriate antibiotic prescribing, were compared. Survey data on four validated indicators of inappropriate antibiotic use and 16 self-reported policy implementation variables from WHO databases were extracted. The average difference for indicators between countries reporting versus not reporting implementation of specific policies was calculated. For 16 selected policies we regressed the four antibiotic use variables on the numbers of policies the countries reported implementing.

Results

Data were available for 55 countries. Of 16 policies studied, four (having a national Ministry of Health unit on promoting rational use of medicines, a national drug information centre and provincial and hospital drugs and therapeutics committees) were associated with statistically significant reductions in antibiotic use of ≥20% in upper respiratory infection (URTI). A national strategy to contain antibiotic resistance was associated with a 30% reduction in use of antibiotics in acute diarrheal illness. Policies seemed to be associated with greater effects in antibiotic use for URTI and diarrhea compared with antibiotic use in all patients. There were negative correlations between the numbers of policies reported implemented and the percentage of acute diarrhoea cases treated with antibiotics (r = -0.484, p = 0.007) and the percentage of URTI cases treated with antibiotics (r = -0.472, p = 0.005). Major study limitations were the reliance on self-reported policy implementation data and antibiotic use data from linited surveys.

Conclusions

Selected essential medicines policies were associated with lower antibiotic use in low and middle income countries.     

Effect of support materials on antibiotic MSW2000 production by immobilized Streptomyces violatus

The production of an antibiotic by free and immobilized cells of Streptomyces violatus through entrapment or adsorption on different materials was investigated. S. violatus entrapped in Ca-alginate beads gave low antibiotic activity compared to the free cell or adsorbed cell, while the adsorption of S. violatus on sponge cubes yielded the highest antibiotic concentration after 4 days of incubation in static cultures. A starch concentration of 10 g/L was optimum for the production of the antibiotic by adsorbed cells. The weight and size of the sponge cubes used for immobilization influenced production of the antibiotic and the optimum weight and size of the sponge were 0.8 g and 1.0 cm(3), respectively, yielding a maximum antibiotic production of 280 mg/ml. Maximum antibiotic production was obtained at an initial pH value of 7.5 and in an inoculum size of 3 ml (spore suspension) per 50 ml. The production of the antibiotic in a fixed-bed bioreactor reached a maximum value after 2 days of incubation at a circulation rate of 30 ml/h. The immobilized cells in the bioreactor were reused seven successive times over a period of 14 days.     

Antibiotic resistant Escherichia coli and Salmonella in Russian rooks (Corvus frugilegus) wintering in the Czech Republic

AIMS: To characterize antibiotic resistant Escherichia coli and Salmonella isolates in rooks wintering in the Czech Republic. METHODS AND RESULTS: Three hundred and sixty-three faeces samples from rooks were examined for antibiotic resistant Escherichia coli and Salmonella. Altogether 13.7%E. coli isolates were resistant to antimicrobial agents tested. The dominant type of resistance was to tetracycline. Resistant E. coli isolates were examined for antibiotic resistance genes and class 1 integrons. Five of 29 antibiotic resistant isolates possessed the int1 gene. Nine Salmonella isolates (2.5%) were found in rook faeces. All the isolates belonged to serotype Salmonella enterica serovar Enteritidis phage type PT8 and PT23. CONCLUSIONS: The study suggests that rooks can be infected by antibiotic resistant E. coli and Salmonella isolates, probably reflecting the presence of such isolates in their sources of food and/or water in the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Rooks can serve as reservoirs and vectors of antibiotic resistant E. coli and Salmonella isolates and potentially transmit these isolates over long distances.     

Evolution and ecology of antibiotic resistance genes

A new perspective on the topic of antibiotic resistance is beginning to emerge based on a broader evolutionary and ecological understanding rather than from the traditional boundaries of clinical research of antibiotic-resistant bacterial pathogens. Phylogenetic insights into the evolution and diversity of several antibiotic resistance genes suggest that at least some of these genes have a long evolutionary history of diversification that began well before the 'antibiotic era'. Besides, there is no indication that lateral gene transfer from antibiotic-producing bacteria has played any significant role in shaping the pool of antibiotic resistance genes in clinically relevant and commensal bacteria. Most likely, the primary antibiotic resistance gene pool originated and diversified within the environmental bacterial communities, from which the genes were mobilized and penetrated into taxonomically and ecologically distant bacterial populations, including pathogens. Dissemination and penetration of antibiotic resistance genes from antibiotic producers were less significant and essentially limited to other high G+C bacteria. Besides direct selection by antibiotics, there is a number of other factors that may contribute to dissemination and maintenance of antibiotic resistance genes in bacterial populations.     

Significant Reduction of Antibiotic Consumption and Patients’ Costs after an Action Plan in China, 2010–2014

Introduction

On July 1, 2011, the Chinese government launched a national Action Plan for antibiotic stewardship targeting antibiotic misuse in public hospitals. The aim of this study was to evaluate the impacts of the Action Plan in terms of frequency and intensity of antibiotic utilization and patients costs in public general hospitals.

Methods

Administrative pharmacy data from July 2010 to June 2014 were sampled from 65 public general hospitals and divided into three segments: (1) July 2010 to June 2011 as the preparation period; (2) July 2011 to June 2012 as the intervention period; and (3) July 2012 to June 2014 as the assessment period. The outcome measures included (1) antibiotic prescribing rates; (2) intensity of antibiotic consumption; (3) patients costs; and (4) duration of peri-operative antibiotic treatment in clean surgeries of thyroidectomy, breast, hernia, and orthopedic procedures. Longitudinal and cross-sectional analyses were conducted.

Results

Longitudinal analyses showed significant trend changes in the frequency and intensity of antibiotic consumption, the patients’ costs on antibiotics, and the duration of antibiotic treatment received by surgical patients undergoing the 4 clean procedures during the intervention period. Cross-sectional analyses showed that the antibiotic prescribing rates were reduced to 35.3% and 12.9% in inpatient and outpatient settings, that the intensity of antibiotic consumption was reduced to 35.9 DDD/100 bed-days, that patients’ costs on antibiotics were reduced significantly, and that the duration of peri-operative antibiotic treatment received by surgical patients undergoing the 4 types of clean procedures decreased to less than 24 hour during the assessment period.

Conclusion

The Action Plan, as a combination of managerial and professional strategies, was effective in reducing the frequency and intensity of antibiotic consumption, patients’ costs on antibiotics, and the duration of peri-operative antibiotic treatment in the 4 clean surgeries.