武汉地区门诊皮肤软组织感染患者中甲氧西林敏感金黄色葡萄球菌PVL基因携带及耐药性检测

目的 探讨从武汉地区门诊皮肤软组织感染（SSTI）患者中分离的甲氧西林敏感金黄色葡萄球菌（MSSA）携带杀白细胞毒素（PVL）基因及耐药特征。 方法 收集2011—2013年在武汉市5所医疗机构门诊就诊SSTI患者中分离的182株MSSA,采用纸片扩散法进行药敏试验,多重PCR法检测mecA基因和PVL基因。结果 182株MSSA中有65株PVL阳性,阳性率为35.71%。不同病种PVL阳性率差异有统计学意义（χ2 = 49.76,P = 0.00）,其中疖/痈（7/7）、毛囊炎（3/3）、脓肿（55.53%,30/57）和脓疱疮（2/4）的检出率较高。PVL阳性患者年龄［（35.40 ± 19.31）岁］小于PVL阴性患者［（43.21 ± 20.75）岁］,差异有统计学意义（t = 2.50,P = 0.01）。在65株PVL阳性MSSA菌株中,耐药率居前3位的依次是氨苄西林（87.69%）、青霉素（53.85%）、红霉素（41.54%）。在117株PVL阴性MSSA菌株中,耐药率居前3位的依次是克林霉素（26.50%）、青霉素（20.51%）、氨苄西林（12.82%）。PVL阳性MSSA菌株对青霉素（χ2 = 21.19）、氨苄西林（χ2 = 97.97）、多西环素（χ2 = 11.61）、环丙沙星（χ2 = 8.07）、红霉素（χ2 = 25.04）、庆大霉素（χ2 = 10.86）的耐药率高于PVL阴性MSSA菌株,差异均有统计学意义（P < 0.05）。 结论 武汉地区门诊MSSA SSTI患者中,PVL阳性率较高,对大多数β内酰胺类抗菌药物耐药,经验治疗可选择氟氯西林、复方磺胺甲恶唑片或多西环素。     

葡萄球菌性烫伤样皮肤综合征的致病金黄色葡萄球菌剥脱毒素基因型及耐药研究

目的 探讨葡萄球菌性烫伤样皮肤综合征（SSSS）致病的金黄色葡萄球菌（简称金葡菌）分泌表皮剥脱毒素（ET）的主要类型及耐药情况。方法 108株金葡菌分离自SSSS（36例）、脓疱疮（36例）及皮肤脓肿（36例）。用多重PCR法测定致病金葡菌菌株产ETA、ETB、ETD基因型，Kirby-Bauer纸片法检测其对20种抗生素的敏感性。结果 36株来源于SSSS的金葡菌 100％ （36/36）为产ET菌株，其中单产ETA 2株（6％），ETB 7株（19％），兼产ETA和ETB 27株（75％）。来源于脓疱疮的36株金葡菌78％ （28/36）为产ET菌株，单产ETA 5株（14％），兼产ETA和ETB 23株（64％），未发现单产ETB金葡菌。而分离自皮肤脓肿的36株金葡菌仅2.8%（1/36）产ET，为兼产ETA和ETB菌株。108株金葡菌均未检测到ETD。金葡菌产ET的型别分布在三组疾病间差异有统计学意义（χ2 = 89.4，P ＜ 0.01），且分离自SSSS的金葡菌株产ET的比例明显高于脓疱疮组（χ2 = 9.0，P < 0.01）和脓肿组（χ2 = 68.1，P < 0.01）。三组病例的致病金葡菌对青霉素、氨苄西林、大环内酯类及克林霉素高度耐药，但对头孢类抗生素均敏感。脓肿组发现2例耐甲氧西林金葡菌株（MRSA）。结论 SSSS及脓疱疮患儿的致病金葡菌主要为产ET菌株，并以兼产ETA和ETB菌株为主。     

178例儿童脓疱疮皮损中金黄色葡萄球菌药敏及随机扩增多态性DNA分析北大核心CSCD

目的探讨儿童脓疱疮皮损中金黄色葡萄球菌的耐药情况,比较敏感株与耐药株的DNA指纹差异。方法对成都地区178例儿童脓疱疮患者皮损分泌物进行细菌培养,对培养出的162株金黄色葡萄球菌（简称金葡菌）进行21种抗生素的药物敏感试验,同时对162株金葡菌进行随机扩增多态性DNA分析。结果从脓疱疮患儿皮损中分离鉴定出病原菌180株,其中金葡菌162株,占90．00％。162株金葡菌中,148株为甲氧西林敏感金葡菌（MSSA）,14株为耐甲氧西林金葡菌（MRSA）。162株金葡菌进行21种抗生素体外药敏试验,敏感率前5位分别为米诺环素、替考拉宁、喹奴普汀、万古霉素、呋喃妥因。耐药率前5位分别为青霉素、红霉素、克林霉素、复方磺胺甲唔唑、四环素。未发现对夫西地酸、呋喃妥因、万古霉素、喹奴普汀、替考拉宁及米诺环素耐药。按DNA条带的大小和数量进行分型,共分为8种基因型,基因型Ⅲ最多占31．48％;基因型Ⅱ占26．54％;基因型Ⅵ占25．93％,这3种基因型占总数的65．43％（106／162）。148株MSSA的基因型有8种,基因型Ⅲ占33．78％,基因型Ⅵ占26．35％,基因型Ⅱ占22．30％。14株MRSA的基因型只有3种,分别为基因型Ⅱ10株（71．43％）,基因型VI3株（21．43％）,基因型Ⅲ1株（7．14％）,以基因型Ⅱ为主。结论成都儿童脓疱疮皮损中病原菌以金葡菌为主,对米诺环素、替考拉宁及喹奴普汀等高度敏感。其RAPD指纹共分为8型,以基因型Ⅲ最多。     

天然抗角蛋白自身抗体抗小鼠金黄色葡萄球菌感染的研究

目的 以高滴度天然抗角蛋白自身抗体(AK auto Ab)转基因小鼠为模型,分析AK auto Ab在抵御金黄色葡萄球菌感染中的作用.方法 取天然抗角蛋白自身抗体转基因小鼠及阴性对照小鼠,ELISA法检测小鼠腹腔冲洗液总IgM、抗角蛋白IgM抗体以及抗金黄色葡萄球菌IgM抗体水平:腹腔接种金黄色葡萄球菌制备感染模型,检测腹腔接种金黄色葡萄球菌后腹腔及肾脏菌落形成单位数量.测定菌负荷,流式细胞仪检测中性粒细胞比率、炎症因子浓度等.结果 ELISA检测发现,转基因小鼠腹腔冲洗液抗角蛋白IgM、抗金黄色葡萄球菌IgM水平高于阴性对照小鼠.差异有统计学意义(P<0.01);菌落形成实验显示,转基因小鼠腹腔及肾脏菌负荷低于阴性对照(P<0.01):流式细胞仪分析发现.转基因小鼠腹腔中性粒细胞比率、炎症因子浓度低于阴性对照(P<0.01).结论 AK auto Ab在小鼠体内对金黄色葡萄球菌感染具有良好的保护作用.     

浅部与深部感染来源白念珠菌氟康唑耐药株药物敏感性及耐药基因突变比较

【摘要】 目的 比较浅部、深部感染来源的氟康唑耐药白念珠菌体外对8种抗真菌药物的敏感性及耐药基因突变。方法 26株深部感染来源白念珠菌耐药株、33株浅部感染来源白念珠菌耐药株,参照CLSI酵母菌检测方案M27-A4测定上述菌株对氟康唑、伏立康唑、伊曲康唑、泊沙康唑、两性霉素B、氟胞嘧啶、特比萘芬、米卡芬净8种药物单独或联合的体外敏感性。提取所有耐药菌株DNA,通过PCR检测ERG3、ERG11、FUR1 3种耐药基因的突变情况。满足正态分布和方差齐性检验的定量资料两组间比较采用独立样本t检验,不满足者组间比较采用Mann-Whitney U检验,定性资料组间比较采用卡方检验。结果 氟康唑、伊曲康唑、伏立康唑、泊沙康唑、氟胞嘧啶的最小抑菌浓度（MIC）在浅部感染组和深部感染组间差异均有统计学意义（均P＜0.05）,而两性霉素B、米卡芬净的MIC两组间差异无统计学意义（均P > 0.05）。96.6%的菌株特比萘芬MIC值＞64 μg/ml,无法进行组间对比。15株白念珠菌（7株深部感染来源、8株浅部感染来源）特比萘芬 + 唑类（氟康唑、伏立康唑、伊曲康唑、泊沙康唑）联合药敏试验均显示为协同效应,部分抑菌浓度（FIC）指数0.033～0.187;氟胞嘧啶 + 唑类、氟胞嘧啶 + 两性霉素B、两性霉素B + 氟康唑组合均无明显协同作用,FIC指数0.56～1.125。浅部感染来源白念珠菌ERG3基因突变包括错义突变V351A（33株,100%）,深部感染来源白念珠菌包括错义突变V351A（13株,50%）、A353T（4株,15%）;浅部感染来源白念珠菌ERG11基因突变包括错义突变I437V（32株,97%）、Y132H（23株,70%）、T123I（16株,48%）、K128T（6株,18%）、D116E（5株,15%）、A114S（4株,12%）、E266D（2株,6%）、G448E（2株,6%）、G465S（2株,6%）,深部感染来源白念珠菌包括I437V（23株,88%）、E266D（13株,50%）、E260G（5株,19%）、V488I（4株,15%）;浅部感染来源白念珠菌 FUR1基因突变包括错义突变R101C（11株,33%）,深部感染来源白念珠菌未检出错义突变。结论 浅部与深部感染来源白念珠菌氟康唑耐药株对药物的敏感性及基因突变位点均有所差别。     

小鼠真皮成纤维细胞成脂分化对金黄色葡萄球菌感染的抵抗效应及机制研究

目的探讨小鼠真皮成纤维细胞(MdFB)成脂分化过程抗金黄色葡萄球菌感染的效应及机制。方法从新生C57BL/6小鼠提取MdFB, 采用脂肪诱导分化培养基培养48 h诱导成脂分化, 之后采用分化维持培养基继续培养。采用实时荧光定量逆转录PCR(RT-PCR)检测MdFB成脂分化0 ～ 6 d抗菌肽蛋白(CAMP)基因mRNA相对表达水平;采用Western印迹法检测MdFB成脂分化培养基上清液CAMP蛋白表达趋势。取12孔板每孔加入1 ml 1 × 106 CFU MdFB, 再加入1 × 107 CFU灭活金黄色葡萄球菌悬液或磷酸盐缓冲液(对照)刺激, 分别采用成脂分化培养基或普通培养基培养4 h, 分为共同作用组、分化对照组、金葡菌刺激组、对照组, 收集细胞, 采用Western印迹及RT-PCR检测CAMP蛋白及mRNA表达。采用成脂分化5 d的MdFB培养基上清液培养金黄色葡萄球菌(5 × 104 CFU/ml), 在10 ～ 24 h内每2小时评估生长活性, 以普通培养基培养的MdFB上清液(正常对照组)和不含细胞的培养基上清液(阴性对照组)作为对照。采用非配对t检验或方差分析比...     

北京地区儿童皮肤感染金黄色葡萄球菌的耐药研究

目的 分析儿童皮肤感染金黄色葡萄球菌的耐药现状及社区获得性耐甲氧西林金黄色葡萄球菌的流行情况。方法 对600例感染性皮肤病患儿皮损分泌物进行细菌培养。应用琼脂稀释法检测抗生素及环丙沙星对培养出的金黄色葡萄球菌的最小抑菌浓度。结果 600例患儿皮损共培养出金黄色葡萄球菌451株，对13种抗生素及环丙沙星的药敏试验结果显示，对青霉素耐药率为93.8%，对红霉素耐药率为87.6%，对克林霉素为71.6%，对四环素、氯霉素、庆大霉素和环丙沙星的耐药率依次为37.3%，13.3%，6.4%和2.2%，对苯唑西林、头孢唑啉、头孢呋辛和莫匹罗星耐药率分别为1.6%，0.4%，0.2%和0.2%，未发现头孢曲松、万古霉素和夫西地酸耐药菌株。结论 儿童社区获得性耐甲氧西林金黄色葡萄球菌分离率为1.6%。治疗社区来源的皮肤金黄色葡萄球菌感染性皮肤病，全身治疗首选耐青霉素酶的半合成青霉素和头孢菌素，外用治疗可选择莫匹罗星或夫西地酸。     

Treatment and prevention of community-associated methicillin-resistant Staphylococcus aureus skin and soft tissue infections

ABSTRACT:   Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as a pathogen in the community with a range of clinical manifestations. Although skin and soft tissue infections (SSTIs) are the most common presentation, invasive and more virulent disease has been observed. Colonization and infection with CA-MRSA can occur in individuals with no prior healthcare exposures but also in distinct groups whose common characteristic appears to be close person-to-person contact. Outbreaks with CA-MRSA have occurred in day care centers, athletic teams, and prisons, and transmission has been documented among family members and within the hospital. Treatment of SSTIs involves incision and drainage, oral or parenteral antibiotic therapy, or topical therapy. Healthcare practitioners in outpatient and inpatient settings need to be familiar with prevention and treatment strategies for CA-MRSA.     

Susceptibility testing and resistance phenotype detection in Staphylococcus aureus strains isolated from patients with atopic dermatitis, with apparent and recurrent skin colonization

Background Staphylococcus aureus colonization is accepted to be an important triggering factor in patients with atopic dermatitis (AD) and antibiotic resistance has been recognized to be a serious problem as a consequence and for the management of AD treatment. Objectives To investigate the antibiotic resistance pattern of S. aureus strains isolated from patients with AD with apparent (lesional and nonlesional skin areas) and recurrent skin colonization and strains obtained from healthy nasal carriers. Methods Eighty‐seven patients (age 23 ± 11·5 years) with mild to severe AD (SCORAD 46·9 ± 16·6), 21 patients (age 19·8 ± 6·7 years) before antistaphylococcal treatment and 177 healthy nasal carriers (age 27·5 ± 8·4 years) were microbiologically assessed for carriage of S. aureus. Colonization of lesional and nonlesional skin areas was quantified by counting the number of colony forming units on the skin surface (log₁₀ CFU cm^?2). Antimicrobial susceptibility and resistance phenotypes of 179 S. aureus strains were assessed with the agar disc‐diffusion method. Results Staphylococcus aureus was isolated from 87% of lesional and 44% of nonlesional skin samples from patients with AD. The colonization density of S. aureus was markedly higher in lesional than in nonlesional skin (P < 0·001), and was positively correlated with AD severity (P < 0·001) and total serum IgE (P < 0·05). Patients with AD had a significantly higher prevalence of chloramphenicol‐resistant S. aureus than nasal carriers (P < 0·01). Similar rates of resistance were expressed to tetracycline, erythromycin, mupirocin, clindamycin and penicillin. Nearly 35% of S. aureus strains from the lesional skin demonstrated different antimicrobial sensitivity pattern compared with strains from nonlesional skin of the same patients with AD. The trend of increasing resistance to chloramphenicol, erythromycin and fusidic acid was observed among S. aureus strains recovered from patients after approximately 75 days of antibiotic treatment. Methicillin‐resistant S. aureus isolates were cultured from two patients, one during exacerbation and the other after subsequent bacterial recolonization. Conclusions Discrepancies in antibiotic sensitivity pattern were observed among S. aureus strains colonizing different sites of AD skin (lesional and nonlesional areas), and also in AD patients with prior antibiotic treatment. Therefore, clinicians should consider repeat microbial susceptibility testing on different body sites of patients with AD when clinically indicated.     

Emergence of two populations of methicillin-resistant Staphylococcus aureus with distinct epidemiological, clinical and biological features, isolated from patients with community-acquired skin infections

BACKGROUND: Community-acquired skin and soft-tissue infections due to methicillin-resistant Staphylococcus aureus (MRSA) are an emerging clinical and epidemiological problem. OBJECTIVES: To characterize community-acquired skin infections caused by S. aureus, and especially MRSA. METHODS: From November 1999 to December 2003, we conducted in a French hospital a prospective epidemiological, clinical and bacteriological study of skin infections acquired in the community, applying strict criteria for true community-acquired MRSA (CA-MRSA) and health-care-associated MRSA (HCA-MRSA). RESULTS: One hundred and ninety-seven patients had 207 skin infections (154 primary and 53 secondary infections). Twenty-two (11%) patients had skin infections caused by MRSA. The incidence of MRSA skin infections acquired in the community rose from 4% in 2000 to 17% in 2003, but the increase was not statistically significant. Six patients (3%) were infected by CA-MRSA and 15 (8%) by HCA-MRSA; one patient was lost to follow-up and could not be classified. CA-MRSA and HCA-MRSA had different epidemiological, clinical and biological characteristics. CA-MRSA infections were more severe than HCA-MRSA infections: all the CA-MRSA infections (six of six, 100%) required surgical treatment, compared with only two (15%) of 13 with HCA-MRSA infection (P < 0.001). CA-MRSA all belonged to the same clonal strain, harbouring an agr type 3 allele and the Panton-Valentine leucocidin genes (not detected in HCA-MRSA) and possessing a specific antibiotype. CONCLUSIONS: Two populations of MRSA causing skin infections are emerging in the French community, with distinct epidemiological, clinical and biological characteristics.     

Molecular characteristics of methicillin‐resistant Staphylococcus aureus isolated from skin and soft tissue infections collected in the Japanese nationwide surveillance

Skin and soft tissue infections (SSTI) are a common infection among both outpatients and inpatients. The most frequently isolated bacterium in SSTI was Staphylococcus aureus, a quarter of which was methicillin‐resistant S. aureus (MRSA). In this study, to investigate molecular epidemiology of the 141 MRSA strains collected in the Japanese nationwide surveillance, we performed multiplex real‐time polymerase chain reaction to detect staphylococcal cassette chromosome mec (SCCmec) type and virulence genes. The percentage of SCCmec types I, II, III and IV was 1.4%, 52.5%, 5.7% and 40.4%, respectively. According to the SCCmec type, we classified the strains into health‐care‐associated (HA)‐MRSA (n = 84) and community‐associated (CA)‐MRSA (n = 57). Among the virulence genes, the percentage of enterotoxin C gene‐positive strains was significantly higher in CA‐MRSA than in HA‐MRSA. No significant differences were detected between the two groups in terms of antibiotic susceptibility and patients’ background information, classification of SSTI or symptoms of SSTI.     

Are there predominant strains and toxins of Staphylococcus aureus in atopic dermatitis patients? Genotypic characterization and toxin determination of S. aureus isolated in adolescent and adult patients with atopic dermatitis

The colonization of Staphylococcus aureus is one of the most important aggravating factors of atopic dermatitis (AD). Until now, the importance of S. aureus in AD and a positive correlation between colonization with S. aureus and clinical severity/skin barrier function has been demonstrated. The aim of this study was to determine whether there are certain clones of S. aureus which colonize the skin of AD patients. For this purpose, the genotype of S. aureus isolated from AD patients was examined by newly-developed typing methods. With 36 strains of S. aureus isolated from 35 patients with AD, spa typing, multi-locus sequence typing (MLST), and staphylococcal toxin gene assay by multiplex polymerase chain reaction, were performed. Clinical severity and skin barrier function were evaluated with eczema area and severity index (EASI) and with transepidermal water loss (TEWL). Among 36 strains of S. aureus , 14 sequence types (ST) and 20 spa types were identified, suggesting a very heterogeneous genetic composition of S. aureus and the absence of a prevailing genotype in S. aureus colonized with AD patients. Furthermore, there was no specific genotype of S. aureus which was associated with the clinical severity of AD or skin barrier dysfunction. A toxin gene assay, however, showed the predominance of S. aureus strains carrying sea and/or tsst-1 . To the best of our knowledge, this is the first report to show the genetic composition of S. aureus strains isolated from AD patients determined by sequence-based typing methods.     

176例天疱疮住院患者皮损分泌物培养及药敏试验研究

【摘要】 目的 分析天疱疮患者皮损分泌物培养及药敏试验结果,优化天疱疮的处理方案。方法 回顾性分析2008年1月至2018年12月于安徽医科大学第一附属医院皮肤性病科住院的天疱疮患者皮损分泌物培养及药敏试验结果。结果 入选患者176例,156例 （88.64%） 皮损分泌物培养出细菌和/或真菌,包括25种细菌和10种真菌,其中104例（66.67%）培养出1种病原体,52例（33.33%）培养出2种及以上病原体。134例（76.14%）检出革兰氏阳性球菌,其中金黄色葡萄球菌80例、溶血葡萄球菌21例、表皮葡萄球菌16例;66例（37.50%）检出革兰氏阴性杆菌;24例（13.64%）检出真菌。95例复发患者中89例（93.68%）分泌物培养阳性,81例初发患者中67例（82.72%）分泌物培养阳性,两组阳性率比较,χ2 = 5.22,P < 0.05。金黄色葡萄球菌阳性患者药敏试验结果显示,97.26%对万古霉素敏感,97.18%对利奈唑胺敏感,87.14%对利福平敏感。结论 天疱疮患者并发皮肤感染常见,以革兰氏阳性球菌感染为主,其中金黄色葡萄球菌对万古霉素、利奈唑胺、利福平的敏感性高。     

Antimicrobial susceptibility of Staphylococcus aureus isolated from children with impetigo in China from 2003 to 2007 shows community‐associated methicillin‐resistant Staphylococcus aureus to be uncommon and heterogeneous

Background The number of patients with impetigo caused by community‐associated methicillin‐resistant Staphylococcus aureus (CA‐MRSA) has been increasing. Objectives To investigate the antimicrobial susceptibility of S. aureus causing impetigo in children in China from 2003 to 2007 and further characterize isolates of CA‐MRSA. Materials and methods We examined 984 S. aureus isolates for antimicrobial susceptibility to 11 antimicrobials using the agar dilution method. CA‐MRSA isolates were analysed for Panton–Valentine leucocidin (PVL) genes, and staphylococcal cassette chromosome mec (SCCmec) typing was performed. Results The largest proportion (94·5%) of strains were resistant to penicillin, followed by erythromycin (86·2%) and clindamycin (69·6%). In total 772 of 984 (78·5%) S. aureus strains were multiresistant. The incidence of CA‐MRSA was 1·1%, with a high rate of resistance to clindamycin (90·9%) and tetracycline (72·7%), but all were susceptible to ciprofloxacin. The susceptibility profiles of MRSA to other antimicrobial agents were similar to those of methicillin‐sensitive S. aureus (MSSA). None of the S. aureus strains were resistant to vancomycin and fusidic acid; moreover, only one strain was resistant to mupirocin. Typing of the SCCmec showed that 54·5% were type IV, 18·2% were type V and 9·1% were type VI. All the PVL‐positive CA‐MRSA carried SCCmec type IV. Conclusions CA‐MRSA is still relatively uncommon and heterogeneous in children in China. Penicillin and erythromycin are no longer appropriate agents. Effective antibiotic agents for patients with impetigo are mupirocin and fusidic acid.