Prevalence and trend analysis of antimicrobial resistance in clinical Escherichia coli isolates collected from diseased pigs in the USA between 2006 and 2016

Antimicrobial resistance (AMR) is an emerging threat to both human and animal health. Antimicrobial use and resistance in food animal production, including swine, has received increased scrutiny as a source of resistant foodborne pathogens. Continuous surveillance of AMR in bacterial isolates of swine origin can guide in conservation of antimicrobials used in both human and swine medicine. The objective of this study was to evaluate the prevalence and trends of the phenotypic AMR in Escherichia coli of swine origin isolated from clinical samples at the Minnesota Veterinary Diagnostic laboratory between 2006 and 2016. The prevalence of resistance to ampicillin, tetracyclines and sulphadimethoxine remained greater than 50% throughout the period. There was a drastic change in enrofloxacin resistance, increasing from less than 1% to more than 20% between 2006 and 2016 (annual relative increase of 57% between 2006 and 2013 and 16% between 2013 and 2016). The prevalence of resistance to other antimicrobials remained constant (ceftiofur, oxytetracycline and chlortetracycline) or changed significantly (annual relative changes of less than 10%) for at least some time‐period between 2006 and 2016 (ampicillin, florfenicol, gentamicin, neomycin, sulphadimethoxine, trimethoprim‐sulphamethoxazole and spectinomycin). Rarefaction analysis revealed an increase in the number of unique combinations of AMRs per year. Network analysis was performed by estimating and plotting partial correlations between minimum inhibitory concentrations (MICs) of various antimicrobials. An increase in strength of these networks was observed, particularly in networks created after 2010, which can be indicative of increased multiple AMR in these isolates. These results provide valuable insight into the trends in AMR in E. coli of swine origin in the USA and act as supplementary information to the existing active AMR surveillance systems.     

Inadequate use of antibiotics and increase in neonatal sepsis caused by resistant bacteria related to health care assistance: a systematic review

Background

Technologies and life support management have enhanced the survival of preterm infants. The immune system of newborns is immature, which contributes to the occurrence of healthcare-associated infections. The overlap of several conditions with neonatal sepsis and the difficulty of diagnosis and laboratory confirmation during this period result in a tendency to over-treat neonatal sepsis. The use of antimicrobial agents is a risk factor for multidrug-resistant bacterial infections. This work aimed to perform a systematic review of the relationship between inadequate use of antimicrobial agents and increase in neonatal sepsis related to healthcare assistance, due to bacterial resistance.

加强医疗病房呼吸机相关性肺炎病原菌及其耐药性分析

目的：探讨加强医疗病房机械通气患者呼吸机相关性肺炎（VAP）的病原菌群及药敏结果。方法：回顾性分析132例VAP临床资料及下呼吸道分泌物细菌培养情况。结果：ICU中机械通气患者VAP发生率为52.2%；病原菌以G-菌为主，其中铜绿假单胞菌、鲍曼不动杆菌、肺炎克雷伯菌、大肠埃希菌及金黄色葡萄球菌是主要致病菌，且耐药严重。结论：加强VAP病原学监测，合理应用抗生素，提高VAP诊断和治疗水平。     

呼吸道标本中腿伤克斯特菌的鉴定、生物学特性及药 物敏感性分析

摘要：目的 探讨腿伤克斯特菌的鉴定方法、生物学特性及药物敏感性，为其鉴定和临床用药提供参考依据。 方法 应用 Ｖｉｔｅｋ ２ Ｃｏｍｐａｃｔ 全自动微生物鉴定系统、基质辅助激光解吸电离飞行时间质谱（ＭＡＬＤＩ?ＴＯＦ ＭＳ）仪及 １６Ｓ ｒＤＮＡ 测序对菌株 进行鉴定；采用微量生化反应管分析其生物学特性；利用 Ｖｉｔｅｋ ２ Ｃｏｍｐａｃｔ 全自动微生物鉴定药敏系统对其进行药物敏感性分 析。 结果 血平板、含万古霉素的巧克力平板上菌落呈灰白色，麦康凯平板上菌落呈浅紫色，菌落均表面粗糙、扁平且迁徙生 长；镜下形态为革兰阴性球杆菌；经菌种鉴定，４ 株菌株均为腿伤克斯特菌；该菌过氧化氢酶、动力试验阳性，其他常规生化试 验均为阴性；药敏结果显示菌株对氟喹诺酮类抗菌药物敏感、中介或耐药，对青霉素类、头孢类、酶抑制剂类、碳青霉烯类、氨 基糖苷类、磺胺类等常见抗菌药物均敏感。 结论 ＭＡＬＤＩ?ＴＯＦ ＭＳ 及 １６Ｓ ｒＤＮＡ 测序技术有助于该菌的检出，临床应增强对此 菌的认识。     

Mechanisms of toxicity mediated by neutrophil and eosinophil granule proteins

Neutrophils and eosinophils are granulocytes which are characterized by the presence of granules in the cytoplasm. Granules provide a safe storage site for granule proteins that play important roles in the immune function of granulocytes. Upon granulocytes activation, diverse proteins are released from the granules into the extracellular space and contribute to the fight against infections. In this article, we describe granule proteins of both neutrophils and eosinophils able to kill pathogens and review their anticipated mechanism of antimicrobial toxicity. It should be noted that an excess of granules protein release can lead to tissue damage of the host resulting in chronic inflammation and organ dysfunction.     

Bovine milk RNases modulate pro-inflammatory responses induced by nucleic acids in cultured immune and epithelial cells

Activation of innate immune receptors by exogenous substances is crucial for the detection of microbial pathogens and a subsequent inflammatory response. The inflammatory response to microbial lipopolysaccharide via Toll-like receptor 4 (TLR4) is facilitated by soluble accessory proteins, but the role of such proteins in the activation of other pathogen recognition receptors for microbial nucleic acid is not well understood. Here we demonstrate that RNase4 and RNase5 purified from bovine milk bind to Salmonella typhimurium DNA and stimulate pro-inflammatory responses induced by nucleic acid mimetics and S. typhimurium DNA in an established mouse macrophage cell culture model, RAW264.7, as well as in primary bovine mammary epithelial cells. RNase4 and 5 also modulated pro-inflammatory signalling in response to nucleic acids in bovine peripheral blood mononuclear cells, although producing a distinct response. These results support a role for RNase4 and RNase5 in mediating inflammatory signals in both immune and epithelial cells, involving mechanisms that are cell-type specific.