江苏省2012-2015年伤寒/副伤寒沙门菌耐药及分子分型研究

目的 回顾性分析2012-2015年江苏省伤寒/副伤寒沙门菌的耐药表型和分子分型特征。方法 采集江苏省伤寒/副伤寒监测病例的血液和粪便标本,分离培养伤寒/副伤寒沙门菌后进行生化鉴定和血清分型;采用Kirby-Bauer纸片法检测菌株对抗菌药物的敏感性;应用PFGE技术对伤寒和甲型副伤寒沙门菌进行分子分型。结果 134株伤寒沙门菌和甲型副伤寒沙门菌对萘啶酸的耐药率最高,分别为61.2%和86.7%,其余抗生素的耐药率均低于15.0%。伤寒和甲型副伤寒沙门菌中只耐1种抗生素的菌株最多,多重耐药菌在伤寒沙门菌中占2.6%,而在甲型副伤寒沙门菌中占13.3%。2015年伤寒沙门菌的全敏感菌株构成比较2012年增加了44.3%,同年副伤寒沙门菌中出现了耐5种和6种抗生素的多重耐药株。甲型副伤寒沙门菌可分为8种PFGE型别,多重耐药株与其他菌株条带相似性低,不同型别与耐药谱有对应关系;伤寒沙门菌可分为68种PFGE型别,不同型别间变异度较大,与耐药谱无对应关系。结论 2012-2015年江苏省伤寒/副伤寒沙门菌对抗生素的耐药性总体随时间降低,耐药种类数有所增加。伤寒沙门菌株PFGE带型呈现多样性,无耐药谱对应性;而甲型副伤寒菌株PFGE带型较少,有耐药谱对应性。需要加强重点地区重点型别菌株的监测。     

杭州市2002-2008年甲型副伤寒沙门菌分子分型研究

目的研究2002-2008年杭州市甲型副伤寒疫情分离株的亲缘性,并探讨脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）在甲型副伤寒沙门菌分子分型中的应用。方法对404株甲型副伤寒沙门菌运用脉冲场凝胶电泳（PFGE）进行分子分型,并用K-B法测定菌株抗生素敏感性。挑选9株甲型副伤寒沙门菌进行多位点序列分型（MLST）以及稳定性试验。结果 404株甲型副伤寒沙门菌可分为6个PFGE型和4个耐药型,P1型和P2型属于同一个克隆系,该克隆系菌株占试验菌株数的99%,分离自临安市的310株菌均为P1型,分离自杭州市西湖区的主要菌型是P2型和P1型。9株甲型副伤寒沙门菌根据SucA位点的差异可分为2个MLST型。结论杭州市2002-2008年的甲型副伤寒疫情由同一克隆系的菌株主导。PFGE、MLST分型方法各有侧重,可互为补充。     

浙江省伤寒副伤寒沙门菌耐药及分子分型

目的了解浙江省伤寒副伤寒沙门菌耐药及分子分型特点,为伤寒副伤寒防制工作提供依据。方法采用WHO推荐的改良K-B纸片法,对209株甲型副伤寒沙门菌和5株伤寒沙门菌进行14种抗生素敏感性试验;运用脉冲场凝胶电泳分型(PFGE)方法对119株甲型副伤寒沙门菌进行分子分型及流行病学特征分析。结果209株甲型副伤寒沙门菌对红霉素、萘啶酸和利福平100%耐药,对阿米卡星100%敏感,对环丙沙星的敏感率仅为58%;5株伤寒沙门菌对红霉素和利福平100%耐药,对头孢噻吩、头孢噻肟、庆大霉素、环丙沙星、氨苄西林、阿米卡星和阿莫西林/克拉维酸100%敏感;不同地区间的甲型副伤寒沙门菌对大部分药物敏感率一致,只有多西环素存在较大差异;119株甲型副伤寒沙门菌共产生20种PFGE带型,并主要集中在2种同源性较高的型别。结论2008年浙江省伤寒副伤寒以甲型副伤寒菌株为优势株,不同地区甲型副伤寒沙门菌对大部分抗生素敏感率一致;高发地区(台州)的菌株PFGE带型比较分散,可能与菌株变异有关。     

广东省2007年度非伤寒沙门菌监测及病原学特征分析

目的 了解广东省腹泻病患者中非伤寒沙门菌感染情况和菌株的血清型别、分布、耐药性变化.方法 对纳入研究的腹泻病患者进行非伤寒沙门菌检测,对分离到的菌株进行血清分型、药物敏感性试验和脉冲场凝胶电泳(PFGE)分型.结果 2007年度共检测1128份腹泻粪便标本,分离到71株沙门菌,阳性检出率为6.29%;共分得29种血清型,肠炎和鼠伤寒沙门菌居多;大多数沙门菌对常用的头孢类和喹诺酮类抗生素敏感,鼠伤寒沙门菌的耐药率普遍较肠炎和斯坦利沙门菌高;除肠炎沙门菌外,其余的血清型没有同一PFGE型别的菌株;用Xba Ⅰ酶切17株肠炎沙门菌可分为PFGE-XbaⅠ 1～8型,其中PFGE-XbaⅠ 4型为优势型别.用Sfi Ⅰ和Not Ⅰ酶对12株肠炎沙门菌进行再分型,综合用Xba Ⅰ/Sfi Ⅰ/Not Ⅰ三种酶的结果 发现仍有三组菌的PFGE图谱是完全一致的.结论 2007年度广东省非伤寒沙门菌的感染多数为散发病例,头孢类和喹诺酮类抗生素是治疗非伤寒沙门菌感染的首选药物.     

2008年-2010年上海市部分伤寒副伤寒沙门菌耐药分析及分子分型

目的:了解上海市2008年-2010年伤寒、副伤寒沙门菌的耐药及分子分型特点,初步掌握伤寒、副伤寒沙门菌的分子流行特点,为今后的防制工作提供科学依据。方法:采用WHO推荐的改良K-B纸片法,对18株伤寒、副伤寒沙门菌进行13种抗生素敏感性试验;运用脉冲场凝胶电泳分型(PFGE)方法对18株伤寒、副伤寒沙门菌进行分子分型及聚类分析。结果:18株伤寒副伤寒沙门菌对利福平100%耐药,对奈啶酸的耐药率为44.4%,其中伤寒沙门菌对奈啶酸的耐药率为37.5%,5株甲型副伤寒沙门菌对奈啶酸100%耐药,乙型副伤寒对奈啶酸无耐药株。所有菌株对其他11种抗生素均敏感;18株伤寒、副伤寒沙门菌共产生16种PGFE带型,有3株甲型副伤寒沙门菌表现为同一PFGE型别。结论:2008年-2010年伤寒、副伤寒沙门菌对抗生素的敏感性较高;甲型副伤寒沙门菌之间有较高的同源性,伤寒沙门菌的PFGE带型比较分散。     

温州市沙门菌血清型、耐药性和PFGE指纹图谱研究

目的了解2017年温州市沙门菌的血清型、耐药情况和PFGE指纹图谱。方法对分离自腹泻病例的77株沙门菌进行血清分型;采用微量肉汤稀释法对优势菌株进行12种抗生素的药敏试验;采用脉冲场凝胶电泳(PFGE)进行指纹图谱分型研究。结果 77株沙门菌共分为23种血清型,优势血清型为鼠伤寒沙门菌,22株占28.58%;肠炎沙门菌,11株占14.29%。33株优势血清型沙门菌对氨苄西林耐药率最高(84.85%),其次为四环素(69.70%)和萘啶酸(63.64%);多重耐药14株,占42.42%;除氨苄西林、萘啶酸外,鼠伤寒沙门菌的耐药率普遍高于肠炎沙门菌。22株鼠伤寒沙门菌可分成16种PFGE指纹图谱;11株肠炎沙门菌分成3种PFGE指纹图谱。结论温州市食源性沙门菌的血清型分布广泛,耐药状况严重,PFGE指纹图谱呈多样性,其聚集性与血清型存在关联性。     

中国2000-2008年间甲型副伤寒沙门菌脉冲场凝胶电泳和多位点序列分析

目的 分析我国2000-2008年间甲型副伤寒沙门菌流行株的分子分型及病原进化上的特征.方法 应用以Spe Ⅰ为限制性内切酶的脉冲场凝胶电泳(pulsed-field gel electrophoresis,PFGE)方法 和基于9个管家基因位点(aroC、thrA、hisD、purE、sucA、dnaN、hemD、adk和purA)的多位点序列分析(multilocus sequence typing,MLST)分型方法 ,对我国2000-2008年间分离自10个地区的118株甲型副伤寒沙门菌流行株进行分析.结果 应用PFGE方法 将118株甲型副伤寒沙门菌分为32个型,其中包含5株以上的优势PFGE带型有5种.而应用MLST方法 ,所有菌株只分出了2个序列分型(sequence type,ST),各菌株的管家基因序列高度保守,呈现高度克隆化.结论 中国2000-2008年间甲型副伤寒沙门菌菌株应用MLST这种分型方法 很难区分,MLST不适于甲型副伤寒沙门菌的暴发调查和流行病学监测.目前中国的甲型副伤寒是由高度克隆化的菌株引起全国范围的扩散 流行.随着年份的变迁,也积累了散在的变异.     

伤寒与甲型副伤寒沙门菌基因分型与耐药性研究

目的:通过追溯菌株的流行优势型,了解菌株的耐药性,分析流行因素,为查明宁波地区伤寒、副伤寒疫情回升原因提供科学依据。方法:水产品检测采用GB、PCR和mini VIDAS联合检测方法;病人、从业人员检测采用全国临床操作规程或GB方法;菌株鉴定采用VITEK、ATP方法;药物敏感试验采用K-B纸片扩散法;基因分型采用PFGE方法。结果:从11类1500份海产品中检出6株沙门菌,检出率为0.40%,其中甲型副伤寒沙门菌2株,检出率为0.13%,肠炎等沙门菌3株,检出率为0.20%,伤寒沙门菌1株,检出率为0.07%;住院病人及暴发疫情标本中分离到沙门菌593株,其中伤寒沙门菌25株,占4.22%,乙型副伤寒沙门菌1株,占0.17%,甲型副伤寒沙门菌567株,占95.62%;食品、公共场所从业人员检出甲型副伤寒沙门菌2株;病人胆汁中分离到甲型副伤寒沙门菌1株。182株甲型副伤寒沙门菌和3株伤寒沙门菌药敏试验显示,大多数菌株对常用多种抗生素均敏感,其中1株分离于水产品伤寒沙门菌出现多重耐药。14株伤寒沙门菌可分为3个PFGE型,364株甲型副伤寒沙门菌可分为12个PFGE型。结论:宁波地区伤寒、副伤寒疫情回升与食源性有关,同源性试验提示菌株来是同一克隆系的可能性较大,优势流行型为PFGE 2型,且发现宁波地区副伤寒疫情的流行强度与此型细菌相关。检出的伤寒、副伤寒沙门菌对氧哌嗪青霉素、妥布霉素及头孢哌酮等第3代头孢菌素药物显示良好的敏感性,可作为当前预防和治疗的首选药物。伤寒出现多重耐药株,应引起我们的关注。PFGE分型有助于病原的追溯,分析菌株的变迁,为流行病学进一步分析病因提供支持,在确定传播途径等方面具有重要意义。     

中国四省甲型副伤寒分离株脉冲场凝胶电泳分析及分型数据库建立

目的对中国4个甲型副伤寒流行省份的分离株进行标准化脉冲场凝胶电泳（PFGE）分型分析。方法对来自4个省的甲型副伤寒沙门菌利用XbaⅠ酶切染色体DNA进行PFGE分析，利用BioNumerics建立数据库和进行相似性聚类。结果分离自1998-2002年的89株甲型副伤寒分离株共有11种PFGE带型，这些菌株中具有优势带型。有3种带型相似性在96．3％，这3种带型的菌株占到分析菌株的865％，并在不同省份和年度中出现。结论建立了中国甲型副伤寒沙门菌的用于网络监测分析的PFGE技术和数据库，近年中国部分省份的甲型副伤寒沙门菌分离株PFGE型别集中，存在同型菌株的广泛流行。     

多位点序列分型和脉冲场凝胶电泳在肠炎沙门菌分子分型的比较

目的 比较多位点序列分型技术和脉冲场凝胶电泳（PFGE）技术在肠炎沙门菌菌株间分型的分辨率。方法 分别建立肠炎沙门菌的6个管家基因thrA、pure、sucA、aroC、hemD、dnaN和一个特异性的DNA标记Sdf Ⅰ的多位点序列分型技术，及以寡切点的XbaⅠ、SpeⅠ作为限制性内切酶的PFGE方法，并应用上述方法对食品中的分离株进行分型，比较两种方法的分辨率。结果 PFGE可以将50株肠炎沙门菌分为11个型。并且通过双酶系统的双重PFGE分型，还可以将PFGE型别再精细划分为亚型；MLST则揭示了在同一血清型内部，各菌株之间的管家基因碱基序列高度保守，而在沙门菌不同血清型的核苷酸序列之间，则分别存在不同数量的碱基差异。即MLST方法只能用于血清型之间，不能在血清型内部进行分型研究。结论 与MLST比较，PFGE方法在肠炎沙门菌的分型方面显示了比较高的分辨率。     

Laboratory-based surveillance of non-typhoidal Salmonella infections in Guangdong Province, China

Salmonella is one of the most common foodborne pathogens in humans. Laboratory-based surveillance for non-typhoidal Salmonella infection was conducted in Guangdong Province, China to improve understanding about the disease burden and detection of dispersed outbreaks. Salmonella isolated from patients with diarrhea were sent from 16 sentinel hospitals to local public health laboratories for confirmation, serotyping, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis (PFGE). PFGE patterns were analyzed to identify clusters representing potential outbreaks. Between September 2009 and October 2010, 352 (4%) Salmonella isolates were obtained from 9167 stool specimens. Salmonella enterica serotype Typhimurium (45%) and Salmonella enterica serotype Enteritidis (13%) were the most common serotypes, and multidrug resistance was high, especially in Salmonella Typhimurium isolates. PFGE patterns of obtained Salmonella isolates were found to be diverse, but a unique PFGE pattern comprising 53 Salmonella Typhimurium isolates were found to occur almost exclusively in infants. Epidemiologic studies are ongoing to determine whether a common exposure is the source of the Salmonella Typhimurium strain frequently isolated from infants.     

肠炎沙门菌多位点序列分型技术的研究

目的研究肠炎沙门菌菌株间的分子特征,建立了分子流行病学研究方法——多位点基因序列分型技术(MLST),并对食品中的肠炎沙门菌分离株进行分型研究。方法选择肠炎沙门菌的6个管家基因thrA、purE、sucA、aroC、hemD、dnaN及一个特异性的DNA标记SdfΙ作为目标基因。对上述基因分别进行PCR扩增及产物测序,用sequencer2.0软件对测序结果进行分析、比对核苷酸的差异。同时,将肠炎沙门菌株与GenBank中鼠伤寒沙门菌LT2相应的基因序列进行比较。结果在肠炎沙门菌标准菌株50041和18株食品分离株之间,6个基因PCR产物范围内的近60000个核苷酸序列完全相同,未观察到同一血清型内的基因突变。而与LT2相比,基因产物发生了1到6个点突变。在对SdfΙ的核苷酸序列比较研究中发现,肠炎沙门菌标准菌株与食品中分离株SdfΙ的核苷酸序列与GenBank中该序列的碱基对比,发生了C182T的点突变。即MLST技术揭示了在同一血清型内各菌株管家基因碱基序列的高度保守。结论MLST方法适用于不同血清型沙门菌株间的分型研究,而不适于同一血清型的菌株分型。     

2006-2011年福建省沙门菌监测菌株血清型分布及耐药性分析

目的分析福建省沙门菌监测病人菌株血清型分布和耐药性情况。方法依据我省制定的沙门菌监测方案,在全省5个地市设立沙门菌监测点开展工作。结果2006～2011年共分离出449株沙门菌,均为肠道沙门菌内的亚种I和亚种HIb,分属于10个群（11个亚群）,39个血清型,其中A～F群占98．89％,鼠伤寒和肠炎沙门菌是我省检出率最高的2种血清型。同时我省新增了1个P群及10个血清型（变种）。鼠伤寒沙门菌仍是我省严重耐药的血清型,沙门菌多数菌株对萘啶酸、链霉素、磺胺、甲氧苄啶、复方新诺明、四环素、氨苄西林有不同程度的耐药,对三代头孢、环丙沙星、阿莫西林＋棒酸多数菌株敏感。结论鼠伤寒和肠炎沙门菌为我省2个主要的血清型,多数菌株对萘啶酸、链霉素、磺胺类、四环素、氨苄西林有不同程度的耐药。     

沙门菌脉冲场凝胶电泳分型与血清型的对应关系

目的分析沙门菌脉冲场凝胶电泳分型(PFGE)与血清分型之间的对应关系.方法选择中国细菌性传染病分子分型实验室监测网络PulseNet China沙门菌监测数据中鼠伤寒(Typhimurium)、肠炎(Enteritidis)、德尔卑(Derby)、阿贡纳(Agona)及山夫登堡(Senftenberg)前五位常见血清型菌株共1230株,进行PFGE聚类分析,以血清分型作为参照进行比对.确定这5种血清型PFGE优势带型的共有条带.结果1230株菌株中,1149株经PFGE预测的血清型与实际血清型一致,PFGE预测血清型的准确率为93.4%.5种血清型经PFGE预测的血清型阳性预测值多在90.0%以上、阴性预测值均在95.0%以上.结论PFGE聚类对5种常见血清型沙门菌血清分型具有较好的提示及验证作用.     

Vertical and horizontal transmission of salmonella within integrated broiler production system

Salmonella remains one of the leading causes of food-borne illness in the United States, and many key questions regarding the introduction and persistence in animal production systems still remain. In order to understand the ecology of Salmonella within an integrated commercial broiler production system, 289 Salmonella enterica were recovered from two integrated poultry farms during the production and processing of seven consecutive flocks. The variety and prevalence of Salmonella serotypes differed between farms. Overall, 15 serotypes were identified, with the most common being Typhimurium (55%), Montevideo (7.9%), Kentucky (9%), and Enteritidis (9.7%). Salmonella Typhimurium and Enteritidis isolates recovered from processed carcasses from Farm One were further characterized using pulsed-field gel electrophoresis (PFGE), and were shown to be indistinguishable from isolates recovered from the poultry house environment and mice trapped on this farm. Additionally, the same broiler S. Typhimurium and S. Enteritidis strains, identified by PFGE, were also isolated from samples taken at a company breeder farm, suggesting vertical transmission of these Salmonella serotypes in this poultry production system. Results indicate that management practices at the breeder level may have a profound effect on the transmission and persistence of salmonellae within an integrated production system, as well as on the potential contamination of poultry-derived products.     

侵袭性非伤寒沙门菌血清型和耐药性分析

目的分析7株侵袭性非伤寒沙门菌(iNTS)的血清型和耐药性。方法针对收集的7株iNTS菌株,开展血清学鉴定、药物敏感性实验以及全基因组测序,并对血清型、MLST型和耐药基因进行鉴定、注释和分析。结果7株iNTS菌株中,包含1株鼠伤寒血清型和2株Ⅰ4,[5],12:i:-(ST34型)、2株肠炎血清型、1株科瓦利斯血清型和1株未知血清型Ⅰ4,[5],12:d:-(ST279型),其中6株为单相菌,沙门菌二相鞭毛基因缺失或假基因化可能有助于增强沙门菌侵袭性。未发现替加环素、氨曲南、阿米卡星及头孢类、碳青霉烯类抗生素耐药株,存在1株八重耐药鼠伤寒沙门菌。耐药基因与耐药表型基本相符。结论本研究中的iNTS菌株存在八重耐药株,整体耐药水平尚低但不可忽视。     

2008-2009年北京市沙门菌流行特征和分子分型

目的 分析2008-2009年北京市沙门菌流行特征及脉冲场凝胶电泳(PFGE)分子分型. 方法 对2008-2009年通过WHO全球沙门菌监测系统及北京市肠道门诊监测系统分离到的137株沙门菌进行生化鉴定、血清分型和相关流行病学分析;利用PFGE进行分子分型. 结果 北京市2008-2009年沙门菌的流行具有明显季节性,6-9月份高发,共分离菌株84株,占64.1%(84/131);患者年龄多为18～40岁,占46.1%(58/128);男性80例,女性51例,男女比例为1.57:1.137株沙门菌分属于20种血清型,其中肠炎沙门菌和鼠伤寒沙门菌为优势菌型,分别占46.7%(64/137)和17.5%(24/137).共分71种PFGE带型,其中肠炎沙门菌和鼠伤寒沙门菌都有16种PFGE型别.肠炎沙门菌的4种PFGE型别(JEGX01.CN0001、JEGX01.CN0003、JFGX01.CN0002、JEGX01.CN0019)和鼠伤寒沙门菌的JPXX01.CN0001为优势分子型别. 结论 2008-2009年北京市沙门菌的流行具有性别、年龄和季节性分布特征;PFGE分子型别较多,且存在差异明显的多个克隆系.

Abstract：

Objective To study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009. Methods A total of one hundred thirty-seven isolates recovered from the WHO Global Samonella Surveillance system and entero clinic surveillance system were identified by biochemical tests and serotyping.The related epidemiological informations were also analyzed.The isolates were further typed by PFGE. Results The prevalence of Salmonella from 2008 to 2009 showed obvious seasonal character.High incidence occurred from June to September,and 64.1% (84/131) isolates were recovered in this period.Patients of 18-40 year-old were 46.1% (58/128) and 80 patients were male and 40 patients were female with the ratio of 1.57:1.These 137 Salmonella isolates belonged to 20 serotypes,including Enteritidis (46.7%,64/137) and Typhimurium (17.5%,24/137) as the dominant serotype.In total,71 PFGE profiles were identified.Four PFGE patterns of S.Enteritidis isolates (JEGX01.CN0001,JEGX01.CN0003,JEGXO1.CN0002,JEGX01.CN0019) and S.Typhimurium pattern of JPXX01.CN0001 were dominant patterns. Conclusion The prevalence of Salmonella from 2008 to 2009 showed distribution characteristics of sex,age and seasons.The numerous PFGE patterns of Salmonella showed diversity of these isolates and different clones existed in Beijing.     

Serotypes, antibiotic resistance, and class 1 integrons in Salmonella isolates from pediatric cases of enteritis in Tehran, Iran

The present study was conducted to investigate serotype distribution, antimicrobial resistance patterns, carriage of class 1 integron, and clonality of Salmonella strains isolated from patients aged 0-12 years in Tehran, Iran, during 2007-2008. A total of 139 Salmonella isolates were studied. Salmonella serotypes Enteritidis, Infantis, and Typhimurium included 84.9% of isolates, Enteritidis accounting for 41.7%. The most prevalent resistances were to doxycycline (64.7%), nalidixic acid (61.2%), tetracycline (51.8%), and streptomycin (42.8%). Fifty-three (38.1%) isolates contained class 1 integron. Eight different gene cassettes were identified, aadA1 being the most frequently encountered. Pulsed-field gel electrophoresis showed that integron-positive Salmonella strains belonging to serotypes Infantis, Enteritidis, and Typhimurium were attributed to two, three, and five different pulsotypes, respectively. The findings indicated that the distribution and drug resistance pattern of most prevalent Salmonella serotypes were broadly similar to that reported globally from human isolates. Presence of class 1 integrons was common among Salmonella serotypes in Tehran, Iran. Concurrent clonal expansion and horizontal transmission events seem to contribute to increase in drug resistance prevalence among Salmonella serotypes.     

Genomic diversity within phage types of Salmonella enterica ssp. enterica serotypes Enteritidis and Typhimurium

The diversity among 1354 strains of Salmonella enterica subsp. enterica, serotype Enteritidis (n = 847) and Typhimurium (n = 507) isolated in Finland in 1991-2002 (n = 608) and in 2003 (n = 746) were studied. The former strains were studied retrospectively by phage typing and pulsed-field gel electrophoresis (PFGE) harmonized in the European Salm-gene project. The latter strains were studied prospectively, and the results correlated to their antimicrobial susceptibility and association with travel to popular tourist destinations. During both periods, S. Enteritidis phage types (PTs) PT1 and PT4, and S. Typhimurium definite types (DTs) DT1 and DT104 were the major phenotypes. SENTXB.0001 was the dominating single PFGE type among S. Enteritidis strains (40% in 1991-2002; 57% in 2003), and accounted correspondingly for 23% and 63% of the PT1 strains, and 81% and 88% of the PT4 strains. No PFGE types dominated among the S. Typhimurium strains but a correlation was found between certain phage and PFGE types: among DT1 strains, STYMXB.0098 accounted for 66% (1991-2002) and 98% (2003) and among the DT104 strains STYMXB.0001 accounted for 84% and 97% in the two time periods, respectively. Of the S. Enteritidis strains isolated in 2003, 91% were associated with travel, most commonly to Spain, Greece, and Bulgaria. SENTXB.0001 was the major Salmonella PFGE type in these countries. In contrast, most (55%) S. Typhimurium strains were of domestic origin. While only 1.3% of the S. Enteritidis strains were multiresistant and 24% were resistant to nalidixic acid only, 30% of the S. Typhimurium strains were multiresistant. Among the multiresistant S. Typhimurium strains, R-type ACSSuT and PFGE type STYMXB.0001 of the DT104 complex dominated.