肠杆菌目细菌产耐碳青霉烯酶的基因分型检测方法进展

碳青霉烯类耐药肠杆菌科细菌（CRE）已成为全球性的公共卫生问题。有文献报道由CRE引起的感染，尤其是血流感染，会导致患者死亡率较高，为临床治疗带来了极大的挑战。肠杆菌科细菌耐碳青霉烯类药物的主要机制是细菌产生了不同型别的耐碳青霉烯类水解酶。目前只有少数几种新型抗菌药物可以用于CRE的治疗如头孢他啶/阿维巴坦，但头孢他啶/阿维巴坦对持有金属β内酰胺酶的CRE没有活性，所以快速、准确地检测CRE菌株所产碳青霉烯酶种类，对临床合理选择抗菌药物至关重要。本文就目前检测肠杆菌科细菌耐碳青霉烯类药物的基因分型实验方法的优缺点进行总结分析。     

The relationship between nasal and conjunctival cultures of antimicrobial-resistant isolates of methicillin-resistant Staphylococcus aureus

PurposeNasal screening is performed to avoid the complications of postoperative surgical site infections (SSI), especially those due to antimicrobial-resistant species such as methicillin-resistant Staphylococcus aureus (MRSA). This study examined the relationship between bacterial isolates from the conjunctiva and the nasal cavity.MethodsAll patients were diagnosed with ocular surface infections, and the organisms in the conjunctiva and the nasal cavity were isolated. We investigated the relationship of the following antimicrobial-resistant bacteria between the conjunctiva and the nose: MRSA, methicillin-resistant CNS (MRCNS), levofloxacin-resistant (LVFX-R) Corynebacterium spp. Data were analyzed using Fisher’s exact test, and the odds ratio was examined.ResultsThis study included 188 eyes of 188 subjects (87 males and 101 females; mean age 58.5 years, range 11–97 years). MRSA (4 eyes), MRCNS (29 eyes), and LVFX-R Corynebacterium spp. (41 eyes) were identified from the conjunctiva, and MRSA (6 eyes), MRCNS (38 eyes), and LVFX-R Corynebacterium spp. (41 eyes) were identified from the nasal cavity. There was a significant relationship detected between the conjunctiva and the nose for MRSA, MRCNS, and LVFX-R Corynebacterium spp. MRSA displayed high sensitivity (0.750, 95% confidence interval [CI]; 0.301 to 0.987) and specificity (0.984, 95% CI; 0.953 to 0.996) in nasal cavity cultures, and the odds ratio was 181.00 times (95% CI; 18.41 to 2320).ConclusionThis study showed a significant relationship between conjunctival and nasal cultures of MRSA, MRCNS, and LVFX-R Corynebacterium spp., suggesting that nasal cavity culture is a potentially useful screening method for detecting resistant bacteria, especially MRSA, in the conjunctiva.     

Effect of chlorhexidine digluconate on antimicrobial activity,cell viability and physicochemical properties of three endodontic sealers

ObjectiveAssess the biological and physicochemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) leachates with and without chlorhexidine (CHX).MethodsThe sealers were studied in no contact and 1-minute contact with CHX. For biological properties (antibacterial activity and cytotoxicity), leachates were formed in saline of freshly mixed, 1-, 7- and 28 days set sealers. The antibacterial properties of sealer leachates were investigated for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus. The 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate murine fibroblast cell viability after exposure to the leachates. The physical properties (water uptake, sorption, solubility, porosity, surface characteristics) of sealers and the pH of the immersion liquid (saline or distilled water) were also assessed over a 28-days period.ResultsCHX improved the antibacterial properties of the sealer leachates and reduced cell viability for all sealer leachates, except for freshly mixed PCS. BioRoot RCS leachates presented the highest antibacterial properties and cell viability with and without CHX contact. PCS was the material most affected by CHX in terms of physical properties, whereas for AH Plus, solubility was increased. CHX did not affect the physical properties of BioRoot RCS, except for solubility that was decreased. CHX contact did not change sealers’ alkalinity in distilled water whereas it increased it for AH Plus and BioRoot RCS in saline.SignificanceCHX improved the antibacterial efficacy of sealer leachates and either compromised or did not affect cell viability. CHX affected to various extent sealers’ physicochemical properties.     

Fifty shades of graft: How to improve the efficacy of faecal microbiota transplantation for decolonization of antibiotic-resistant bacteria

Background

Spontaneous decolonization of antibiotic-resistant bacteria (ARB) takes time: approximately 25% after 30 days for carbapenem-producing Enterobacteriaceae or extended-spectrum beta-lactamase-producing Enterobacteriaceae. Faecal microbiota transplantation (FMT) has been proposed as a new strategy to promote decolonization in order to reduce the risk of superinfection due to these ARB. This paper discusses the literature on the use of FMT for this indication, and the improvement levers available to promote its efficacy.

应用噬菌体控制假单胞菌的研究进展

假单胞菌属细菌中的部分菌株是动植物和人类的致病菌，也是食品的腐败菌，会导致动植物和人类的高死亡率和严重的食品安全事故。噬菌体作为一种细菌性病毒，特异性高、自我增殖快且无副作用。这些特性使其成为了解决细菌性问题的新思路和新方法。本文就利用噬菌体防控假单胞菌属致病菌和腐败菌在食品、水产、植物、医疗等方面的研究和应用进行综述，以便为后期的深入研究提供一定的参考。     

神经内科院内感染病原菌分布及耐药性分析

目的 分析神经内科患者医院感染病原菌分布及耐药性,为合理选择临床抗菌药物提供依据。方法 选取 2016 年5 月—2019年5 月滕州市中心人民医院神经内科院内感染患者202例,按照《全国临床检验操作规程》标准分离、鉴定细菌,用K-B纸片法进行药敏试验,统计医院感染情况,并对分离病原菌的分布及耐药情况进行回顾性分析。结果 神经内科院内感染以下呼吸道感染为主,占33.17%,其次为泌尿道和消化系统感染,占比为21.29%和13.86%;共分离病原菌268株,其中革兰阴性菌112株,占41.79%;真菌103株,占38.43%;革兰阳性菌53株,占19.78%。革兰阴性杆菌中大肠埃希菌对亚胺培南、头孢哌酮舒巴坦耐药率低于<15%,对哌拉西林和头孢噻肟耐药率>65%;产ESBLs肺炎克雷伯菌、铜绿假单胞菌和大肠埃希菌检出率为分别为37.50% 、34.62%、38.10%;金黄色葡萄球菌对阿莫西林耐药率为91.30%,革兰阳性球菌对利奈唑胺、万古霉素敏感。结论 神经内科院内感染分离病原菌以革兰阴性菌为主,对常用的抗菌药物耐药率高,应合理选用抗菌药物。     

Brucella canis in Commercial Dog Breeding Kennels,Ontario, Canada

We evaluated the prevalence of Brucella canis seropositivity in a convenience sample of dogs from commercial breeding kennels in Ontario, Canada. Overall, 127/1,080 (11.8%) dogs from 23/63 (37%) kennels were seropositive. The prevalence of positive dogs within kennels with >1 positive dog ranged from 3.9% to 100% (median 33%).