沙门菌分离株耐药性分析

目前,沙门菌对羧苄西林、氨苄西林、四环素等抗生素的总体耐药性持续上升。随着抗生素种类不断增加及广泛应用,逐渐出现许多新的耐药菌株,沙门菌耐药谱正发生新的变化⁽¹⁾。     

福建省2018年临床沙门菌分离株血清型及耐药性分析

目的了解福建省2018年哨点医院分离的204株沙门菌的血清型分布及耐药特征。方法对204株沙门菌进行血清学分型,并据CLSI指导原则对14种抗生素进行药敏试验。结果204株沙门菌血清型以鼠伤寒沙门菌为主(63.2%,129/204),其次是肠炎沙门菌(10.8%,22/204),还包括德尔卑沙门菌、斯坦利沙门菌和圣保罗沙门菌等。204株沙门菌对氨苄西林、四环素、氨苄西林/舒巴坦耐药率较高,分别为73.0%、70.1%、52.9%,对亚胺培南耐药率最低(4.0%)。耐3类或3类以上抗生素的多重耐药菌占52.9%。对14种抗生素全部耐药的菌株占4.4%。结论福建省临床来源的沙门菌血清型以鼠伤寒沙门菌为主。沙门菌对氨苄西林及四环素等耐药较为严重,多重耐药现象普遍存在。需做好食源性沙门氏菌的监测工作,从源头预防沙门氏菌感染。     

副伤寒沙门菌耐药性与菌株质粒的监测

目的　了解副伤寒沙门菌的耐药情况及耐药机制。方法　对 1 997～ 2 0 0 1年从桂林地区分离到的 2 92株副伤寒沙门菌进行药敏实验和质粒检测。结果　 2 92株副伤寒沙门菌对痢特灵、头孢氨苄、头孢唑啉、头孢啦定敏感率达 1 0 0 % ,对复方新诺明的耐药率为 80 .0 % ,磺胺甲基异口恶唑 85 .6 % ,对此两种抗生素的耐药性有逐年增高的趋势。菌株多重耐药最多可达 4～ 6种 ,耐药类型以磺胺甲基异口恶唑、复方新诺明、青霉素、红霉素为主。 85 .6 % (2 5 0 / 2 92 )的菌株可检出带有90Mdal的大分子质粒 ,质粒检出率与耐药种类呈正相关 (t=4 .78,P <0 .0 5 ) ,所有耐磺胺甲基异口恶唑和复方新诺明的菌株均能检出该质粒 ,而 2 9株敏感株则未能检出质粒。结论　桂林地区副伤寒杆菌普遍对磺胺甲基异口恶唑和复方新诺明耐药 ,痢特灵、头孢氨苄、头孢唑啉、头孢啦定等抗菌素为桂林地区治疗副伤寒的首选药物。菌株携带 90Mdal大分子质粒 ,与副伤寒菌株的耐药性有关。     

肠炎沙门菌临床分离株耐药性与耐药基因分析

目的对分离自北京、广州、新疆3个地区腹泻病人粪便标本中的肠炎沙门菌菌株进行耐药性监测,并分析其耐药基因的变异情况。方法应用生化试验、血清凝集试验对分离的疑似沙门菌菌株进行鉴定。采用K-B药敏纸片法对鉴定出的肠炎沙门菌进行抗生素敏感性试验。利用PCR技术扩增其耐药基因DNA促旋酶gyrA基因和拓扑异构酶parC基因,同时进行测序。结果共分离鉴定出20株肠炎沙门菌,分离菌株对环丙沙星、庆大霉素、头孢他定、亚胺培南的敏感率为100%,对萘啶酸耐药;75%的菌株呈现多重耐药性(multidrug resistance,MDR)序列比对结果显示gyrA基因Asp87及Gly133密码子处发生了点突变,其中Gly133是新的突变点。未发现parC基因密码子突变。结论肠炎沙门菌临床分离株MDR情况比较严重,对萘啶酸普遍耐药,这可能与20株菌的gyrA基因QRDR的突变相关。为防止多重耐药现象的蔓延和加重,除了应加强耐药性及耐药性相关基因的实验室监测外,临床治疗沙门菌感染时需慎用抗生素。     

南通市市售食品沙门菌菌型分布及耐药性研究

目的：了解南通市市售食品沙门菌污染状况、菌型分布及耐药性,为防治沙门菌病提供科学依据。方法：对采自南通市农贸市场、超市6类372份市售食品样品进行沙门菌分离鉴定、分型、药敏试验。结果：372份市售食品沙门菌的检出率为5．11％,生禽畜肉检出率最高,为12．59％,共检出5个血清型,实验分离到的菌株对头孢类等抗生素敏感,对庆大霉素、环丙沙星等抗生素的敏感性各有差异,农贸市场的检出率明显高于超市。结论：南通市市售食品沙门菌污染以生禽畜肉为主,菌型以血清型较常见,对抗菌药物的敏感性较高,农贸市场的污染状况较严重。     

食品中沙门菌整合子与耐药性关系研究

目的：研究食品中沙门菌的整合子携带情况及整合子与耐药性之间的关系。方法：PCR检测细菌总DNA中1、2、3类整合酶基因，确定细菌携带整合子的情况。整合子阳性菌档进一步检测整合子的可变区，分析插入基因盒的序列。结果：69株大肠菌中25株携带1类整合子，集中分布在对4种以上抗生素耐药的菌株中。插入基因盒主要是dfr(甲氧苄氨嘧啶)和aadA(氨基糖甙类)基因盒，各种基因盒组合中最常见的是difrl—aadA1。结论：细菌的多重耐药性与整合子携带高度一致，但是单个菌株的耐药谱与整合子的耐药基因盒缺乏对应关系。     

2008—2013年北京市17株伤寒和副伤寒沙门菌耐药和分子分型研究

目的分析2008—2013年北京市17株伤寒、副伤寒沙门菌耐药及分子分型。方法对2008-2013年通过对北京市肠道门诊监测系统分离到的17株伤寒、副伤寒沙门菌进行生化鉴定、血清分型并运用纸片法进行药敏检测;利用脉冲场凝胶电泳(PFGE)进行分子分型。结果 17株伤寒、副伤寒沙门菌对三代头孢菌素类药物头孢他啶敏感率达100%,头孢噻肟和头孢曲松敏感率均为93.75%,对氟喹诺酮类药物环丙沙星敏感率为93.75%,萘啶酸耐药率达31.25%。其中16株伤寒、副伤寒沙门菌可分为15种PFGE带型,带型分布较分散。结论北京市伤寒、副伤寒沙门菌分离株对3代头孢类抗生素及环丙沙星敏感;PFGE分子型别较多,无聚集性。     

合肥市零售猪肉中沙门菌分离株多重耐药谱研究

采用Kirby-Bauer法对合肥市零售猪肉中分离的26株沙门菌进行药敏试验,并进行多重耐药谱分析,为抗生素的合理使用提供科学依据.     

合肥市生猪肉沙门菌分离株耐药表型与耐药基因的相关性研究

目的:了解生猪肉中沙门菌分离株耐药表型与耐药基因的携带关系。方法:采用K-B纸片法对生猪肉中26株沙门菌分离株进行22种抗菌药物敏感试验,并应用PCR技术对沙门菌分离株进行耐药基因检测。结果:26株沙门菌总耐药率为61.54%(16/26),其中14株(53.85%)对至少3种以上抗菌药物耐药,属于多重耐药株,强力霉素-四环素-氯霉素-卡那霉素是主要多重耐药谱;3类抗菌药物耐药基因以tetB、Flor和aph(3)-IIa与aadB基因分别检出最高。结论:沙门菌耐药表型测定结果与耐药基因检测结果一致,耐药及多重耐药性与耐药基因的携带相关。     

深圳市2004～2007年分离沙门菌的耐药性分析

目的:分析深圳市2004～2007年分离的67株沙门菌对19种抗生素的敏感性,指导临床合理用药.方法:采用纸片扩散法测定菌株对抗生素的敏感性.结果:对目前临床常用的诺氟沙星、环丙沙星和头孢曲松等敏感率很高.36株菌为耐药菌株,9株菌多重耐药,部分菌株交叉耐药.结论:沙门菌对多种常用抗生素已产生耐药性,临床用药时应予注意.     

北京部分市售整鸡中沙门菌和弯曲菌协同定量污染研究

目的对2013年北京部分市售整鸡样品中沙门菌和弯曲菌的定量污染水平、沙门菌血清型和弯曲菌种水平分布进行研究。方法 2013年5—7月采集北京市售整鸡样品33份,进行样品中沙门菌和弯曲菌的定量检测,并分别对沙门菌和弯曲菌进行血清分型和种水平鉴定。结果 19个样品检出沙门菌,检出率为57.6%;5个样品检出弯曲菌,检出率为15.2%;阳性样品中沙门菌和弯曲菌平均污染水平分别为119.4 MPN/100g和58.6 CFU/g。分离出的166株沙门菌被鉴定为14种血清型,最常见的为肠炎沙门菌,其次为印第安纳沙门菌。从同一样品中分离到共11种2个以上不同血清型组合的沙门菌,最常见的血清型组合为肠炎-印第安纳沙门菌。结论 2013年5—7月北京部分市售整鸡中沙门菌污染率较高、污染水平严重、血清型复杂。     

北京市九城区超市及农贸市场零售整鸡中弯曲菌含量与耐药性分析

目的 调查北京市9个城区超市及农贸市场零售环节整鸡样品中弯曲菌含量及抗生素耐药性情况.方法 于2012年8月至2013年7月,选取北京市9个城区的27个超市和18个农贸市场进行调查,共采集零售整鸡样品240份.用改良Karmali、Preston培养基对样品中弯曲菌数量进行测定,采用革兰染色、乳胶凝集和多重PCR方法分别对样品中的弯曲机进行纯化、分离和类型鉴定,并采用美国农业部弯曲菌定量计数方法,计算样品中弯曲菌含量.采用琼脂稀释法,测定弯曲菌对8种抗生素的最低抑菌浓度(MIC).结果 弯曲菌检出率为26.3％(63/240),共计检出弯曲菌151株,其中空肠弯曲菌85株,结肠弯曲菌66株.弯曲菌含量的P25、P50、P75分别为7.5、45.0、350.0 CFU/g.空肠弯曲菌、结肠弯曲菌对抗生素耐药率为:阿奇霉素[AZI,13％(11/85)、82％(54/85)],氯霉素[CHL,33％(28/85)、42％(28/85)],环丙沙星[CIP,95％(81/85)、100％(85/85)],多西环素[DOX,38％ (32/85)、80％(53/85)],红霉素[ERY,12％ (10/85)、82％(54/85)],庆大霉素[GEN,25％(21/85)、68％(45/85)],四环素[TET,67％(57/85)、73％ (62/85)],所有菌株均对美罗培南(MEP)敏感.空肠弯曲菌多重耐药率为55％ (47/85),结肠弯曲菌为86％(57/66)(x2=16.70,P＜0.01).在151株弯曲菌中,共发现21个抗生素耐药谱,其中空肠弯曲菌耐药谱为20个,结肠弯曲菌耐药谱为10个.空肠弯曲菌中,耐药谱CIP-DOX-TET型比例最高,为22％(19/85),CIP-TET、CHL-CIP-TET和CHL-CIP-GEN型分别为14％(12/85)、9％(8/85)和7％(6/85).结肠弯曲菌中,耐药谱AZI-CHL-CIP-DOX-ERY-GEN-TET型比例最高,为35％ (23/66),AZI-CIP-DOX-ERY-GEN-TET和AZI-CIP-DOX-ERY-TET型分别为21％(14/66)和15％(10/66).结论 北京市9个城区零售整鸡样品弯曲菌检出率和含量较高,尤其以农贸市场现宰杀整鸡样品中弯曲菌含量较多,零售整鸡样品中检出的弯曲菌耐药形势严峻.     

Antimicrobial resistance and genetic relatedness among Salmonella from retail foods of animal origin: NARMS retail meat surveillance

Salmonella isolates were recovered from a monthly sampling of chicken breasts, ground turkey, ground beef, and pork chops purchased from selected grocery stores in six participating FoodNet sites (Connecticut, Georgia, Maryland, Minnesota, Oregon, and Tennessee) in 2002 and an additional two sites in 2003 (California and New York). In 2002 and 2003, a total of 6,046 retail meats were examined, including 1,513 chicken breasts, 1,499 ground turkey samples, 1,522 ground beef samples, and 1,502 pork chops. Retail meat samples tested increased to 3,533 in 2003 as compared to 2,513 in 2002. Overall, six percent of 6,046 retail meat samples (n = 365) were contaminated with Salmonella, the bulk recovered from either ground turkey (52%) or chicken breast (39%). Salmonella isolates were serotyped and susceptibility tested using a panel of 16 antimicrobial agents. S. Heidelberg was the predominant serotype identified (23%), followed by S. Saintpaul (12%), S. Typhimurium (11%), and S. Kentucky (10%). Overall, resistance was most often observed to tetracycline (40%), streptomycin (37%), ampicillin (26%), and sulfamethoxazole (25%). Twelve percent of isolates were resistant to cefoxitin and ceftiofur, though only one isolate was resistant to ceftriaxone. All isolates were susceptible to amikacin and ciprofloxacin; however, 3% of isolates were resistant to nalidixic acid and were almost exclusive to ground turkey samples (n = 11/12). All Salmonella isolates were analyzed for genetic relatedness using pulsed-field gel electrophoresis (PFGE) patterns generated by digestion with Xba1 or Xba1 plus Bln1. PFGE fingerprinting profiles showed that Salmonella, in general, were genetically diverse with a total of 175 Xba1 PFGE profiles generated from the 365 isolates. PFGE profiles showed good correlation with serotypes and in some instances, antimicrobial resistance profiles. Results demonstrated a varied spectrum of antimicrobial resistance and PFGE patterns, including several multidrug resistant clonal groups among Salmonella isolates, and signify the importance of sustained surveillance of foodborne pathogens in retail meats.     

Antimicrobial resistance and resistance genes in Escherichia coli isolated from retail meat purchased in Alberta, Canada

This study analyzed antimicrobial resistance (AMR) and resistance genes in generic Escherichia coli isolated from retail meat samples purchased (2007-2008) in Alberta, Canada, and determined potential associations between resistance phenotypes and resistance genes with relation to the meat types. A total of 422 E. coli isolates from retail chicken, turkey, beef, and pork meats were tested for antimicrobial susceptibility. Multiplex PCRs were used to detect major resistance genes for tetracyclines [tet(A), tet(B), tet(C)], sulfonamides (sul1, sul2, sul3), aminoglycosides (strA/B, aadA, aadB, aac(3)IV, aphA1, aphA2), and β-lactamase (bla(CMY-2), bla(TEM), bla(SHV), bla(PSE-1)). Resistance to ciprofloxacin was not found in any isolate. Overall resistances to clinically important antimicrobials amoxicillin-clavulanic acid (16.8% of isolates) and ceftriaxone (12.6% isolates) were observed. These resistances were observed more frequently (p<0.0001) in chicken-derived E. coli than those from the other meat types. Resistance to multiple antimicrobials (≥ 5) was found in more chicken derived E. coli (32%) than E. coli from other meat types. The β-lactamase genes of clinical importance, including bla(CMY-2) and bla(TEM), were found in about 18% of poultry-derived E. coli and in only 5% of ground beef. The bla(CMY-2) gene was more likely to be found in E. coli from chicken than turkey, beef, or pork meats. The tet(A) gene was associated with bla(CMY-2), whereas bla(CMY-2) and bla(TEM) genes were associated with strA/B genes. Resistance genes for tetracycline, sulfonamides, and aminoglycosides were associated with the phenotypic expression of resistance to unrelated classes of antimicrobials. These data suggest the prevalence of AMR and select resistance genes were higher in poultry-derived E. coli. The multiple associations found between AMR phenotypes and resistance genes suggest a complex nature of resistance in E. coli from retail meat, and hence the use of a single antimicrobial could result in the selection of resistant E. coli not only to the drug being used but to other unrelated classes of antimicrobials as well.     

Antimicrobial drug resistance of Salmonella isolates from meat and humans, Denmark

We compared 8,144 Salmonella isolates collected from meat imported to or produced in Denmark, as well as from Danish patients. Isolates from imported meat showed a higher rate of antimicrobial drug resistance, including multidrug resistance, than did isolates from domestic meat. Isolates from humans showed resistance rates lower than those found in imported meat but higher than in domestic meat. These findings indicate that programs for controlling resistant Salmonella spp. are a global issue.     

零售鸡肉中环丙沙星与头孢噻肟双耐药大肠杆菌的检测与遗传特征分析

目的评估我国社区零售鸡肉中多重耐药大肠杆菌的污染危害。方法2011年4月至12月间,从陕西、广东、内蒙古采集新鲜整鸡样品207个,对环丙沙星与头孢噻肟双耐药大肠杆菌进行分离、遗传分型和药敏分析,并应用PCR扩增和测序方法对喹诺酮和三代头孢耐药机制进行分析。结果 35.7%(73/207)的零售整鸡样品中检出环丙沙星与头孢噻肟双耐药大肠杆菌,以系统发生A群为主(61.6%,45/73),所有菌株均为多重耐药株,优势耐药谱型为AMP-CAZ-CTX-CIP-CHL-SXTTET(n=34)和AMP-CAZ-CTX-CIP-CHL-GEN-SXT-TET(n=24),所有菌株的拓扑异构酶喹诺酮耐药决定区中均有点突变,多数菌株的突变数量为3个(n=56)或4个(n=12),从50个菌株中检出质粒介导喹诺酮耐药机制,包括oqxAB(n=48)、aac(6')-Ib-cr(n=5)、qnrS1(n=5)和qnrS2(n=3)。从72株大肠杆菌中共检出6个blaCTX-M型,其中blaCTX-M-55(n=62)为优势型。结论本研究检测的社区零售整鸡是环丙沙星与头孢噻肟双耐药大肠杆菌的重要储存库。     

Antimicrobial resistance among Salmonella isolates from hospitals in Rome.

The susceptibility to antimicrobial agents of 569 salmonella isolated collected in 1977-8 from patients in hospitals in Rome was tested. Fifty-nine per cent of all isolates were resistant to one or more antimicrobials. Resistance was most common to sulphathiazole, tetracycline, streptomycin, whereas colistin, gentamicin, tobramycin, trimethoprim-sulphamethoxazole and nalidixic acid were the most active in vitro. Multiple resistance was most frequently found in strains of Salmonella wien and S. typhimurium (94% and 38% respectively). A significant change in the resistance pattern of S. wien was observed between 1977 and 1978, with a significant increase of susceptibility to some antimicrobials in 1978. Twenty-one R-plasmids transmissible to E. coli K12 were derived from 46 resistant strains of S. typhimurum.     

Prevalence of antimicrobial resistance among Salmonella isolates from chicken in China

We evaluated the antimicrobial resistance of Salmonella isolated in 2008 from a chicken hatchery, chicken farms, and chicken slaughterhouses in China. A total of 311 Salmonella isolates were collected from the three sources, and two serogroups of Salmonella were detected, of which 133 (42.8%) consisted of Salmonella indiana and 178 (57.2%) of Salmonella enteritidis. The lowest percentage of S. indiana isolates was found in the chicken hatchery (4.2%), followed by the chicken farms (54.9%) and the slaughterhouses (71.4%). More than 80% of the S. indiana isolates were highly resistant to ampicillin (97.7%), amoxicillin/clavulanic acid (87.9%), cephalothin (87.9%), ceftiofur (85.7%), chloramphenicol (84.9%), florfenicol (90.9%), tetracycline (97.7%), doxycycline (98.5%), kanamycin (90.2%), and gentamicin (92.5%). About 60% of the S. indiana isolates were resistant to enrofloxacin (65.4%), norfloxacin (78.9%), and ciprofloxacin (59.4%). Of the S. indiana isolates, 4.5% were susceptible to amikacin and 5.3% to colistin. Of the S. enteritidis isolates, 73% were resistant to ampicillin, 33.1% to amoxicillin/clavulanic acid, 66.3% to tetracycline, and 65.3% to doxycycline, whereas all of these isolates were susceptible to the other drugs used in the study. The S. indiana isolates showed resistance to 16 antimicrobial agents. Strains of Salmonella (n?=?108) carrying the resistance genes floR, aac(6')-Ib-cr, and bla(TEM) were most prevalent among the 133 isolates of S. indiana, at a frequency of 81.2%. The use of pulsed-field gel electrophoresis to analyze the S. indiana isolates that showed similar antimicrobial resistance patterns and carried resistance genes revealed six genotypes of these organisms. Most of these isolates had the common pulsed-field gel electrophoresis patterns found in the chicken hatchery, chicken farms, and slaughterhouses, suggesting that many multidrug-resistant isolates of S. indiana prevailed in the three sources. Some of these isolates were not derived from a specific clone, but represented a variety of genotypes of S. indiana.     

某院流感嗜血杆菌耐药性及其对氨苄西林耐药机制

目的了解流感嗜血杆菌对常用抗菌药物的耐药性及其对氨苄西林的耐药机制。方法采用纸片扩散法和头孢硝噻吩纸片法,对2012年1月1日—12月31日某院住院及门诊患者送检标本分离的流感嗜血杆菌耐药性和β-内酰胺酶进行检测,聚合酶链反应(PCR)法对耐氨苄西林菌株进行TEM型和ROB型β-内酰胺酶基因扩增。结果 100例流感嗜血杆菌感染患者,年龄段分布主要为1~10岁,占61.00%。流感嗜血杆菌对氨苄西林耐药率为35.00%(35株),对复方磺胺甲口恶唑耐药率高,达64.65%;对左氧氟沙星和阿奇霉素敏感率最高,分别为97.96%、96.84%,对环丙沙星、头孢噻肟、氯霉素、头孢呋辛和氨苄西林/舒巴坦敏感率均较高,依次为96.91%、92.78%、85.71%、77.89%和74.75%。100株流感嗜血杆菌中,21株β-内酰胺酶阳性,且均为氨苄西林耐药株。对35株耐氨苄西林菌株进行TEM和ROB基因检测,结果 22株TEM型阳性,未检出ROB阳性株。结论流感嗜血杆菌对复方磺胺甲口恶唑敏感率低,对其他常用抗菌药物敏感率高;流感嗜血杆菌对氨苄西林的主要耐药机制为产TEM型β-内酰胺酶。