2010年广州某医疗中心儿童夏季细菌性腹泻的病原学调查

目的研究广州地区小儿夏季细菌性腹泻的病原菌分布。方法采集2010年5～7月广州市妇女儿童医疗中心珠江新城院区腹泻患儿的大便标本进行常规病原菌的分离培养,通过生化反应和血清凝集试验进行鉴定和分型,并使用金标法对空肠弯曲菌抗原进行检测。结果从110份标本中检出44株病原菌,检出率为40.0%。其中致病性大肠埃希菌17株,2岁以下患儿检出15株;空肠弯曲菌12株,2岁以下患儿检出10株;沙门菌6株;念珠菌纯生长6株;产气荚膜杆菌3株。结论广州地区夏季儿童细菌性腹泻的主要病原菌是致病性大肠埃希菌及空肠弯曲菌,两者的易感人群以2岁以下婴幼儿为主。     

广州市市售食品食源性致病菌污染状况调查

目的了解广州市市售食品中食源性致病菌的污染状况。方法采用随机抽样方法分别对我市10个区以及两个地级市的集贸市场、超市、宾馆饭店及个体熟食销售点的7类食品共363份样品中沙门氏菌、金黄色葡萄球菌、副溶血性弧菌、单增李斯特菌、肠出血性大肠杆菌O157∶H7、空肠弯曲菌等6种致病菌依据国标的方法进行了监测。结果363件样品中检出致病菌72株。其中副溶血性弧菌检出率为33.93%,主要污染水产品;金黄色葡萄球菌为3.00%,主要污染熟食品;沙门氏菌和单增李斯特菌检出率分别为1.93%和0.66%;未检出大肠杆菌O157：H7和空肠弯曲菌。在各类食品中,致病菌带菌数有显著性差异（以χ^2检验,P〈0.005）。水产品致病菌带菌率最高,以副溶血性弧菌为主;其次为生肉类,以检出沙门氏菌为多。结论我市市售食品存在食源性致病菌污染,水产品和生肉类是主要污染食品。应加强市售食品监督管理,以减少可能引起食源性疾病的因素。     

2018年大丰城区菜市场熟食中致病菌检测情况分析

目的 通过对大丰城区菜市场熟食中的致病菌进行监测，了解熟食中微生物的污染情况，提升食品安全监督管理水平。 方法 对2018年1月~12月大丰城区13家菜市场15类475份熟食制品进行随机抽样检查，监测沙门菌、副溶血性弧菌、单增李斯特菌及金黄色葡萄球菌的污染情况及致病菌总检出率。结果 2018年大丰城区菜市场15类475份熟食制品中，共检出致病菌122株、112份，致病菌总检出率按样本份数为23.58%，按株数检出率为25.68%，其中副溶血性弧菌、单增李斯特菌、金黄色葡萄球菌、沙门菌的样本份数检出率分别为7.58%、4.21%、5.26%、6.53%。结论 我区13家菜市场15类475份熟食中，副溶血性弧菌、沙门菌的检出率较高，泥螺、猪头肉等样本污染情况较严重，商家应规范各类熟食的安全加工和保存，加强食品安全监测。     

MALDI- TOF MS快速鉴定腹泻病原菌的评价

目的 基质辅助激光解吸电离飞行时间质谱仪(MALDI-TOF MS)是近年发展迅速的鉴定病原菌的新技术，具有快速、准确、高通量、方便、低成本的优越性，本研究评价MALDI Microflex鉴定腹泻病原菌的效果。方法 收集3家医院临床分离的腹泻病原菌379株，采用提取法对其进行鉴定，评价质谱的鉴定效果；选择其中200株病原菌进行直接涂抹法和提取法前处理，对比鉴定效果。结果 腹泻病原菌包括沙门菌属、气单胞菌属、志贺菌属、大肠埃希菌属、弧菌属、艰难梭菌属、邻单胞菌属、耶尔森菌属等8个菌属，28个菌种，MALDI-TOF MS技术鉴定腹泻病原菌整体在属水平鉴定正确率为87.07%,种水平鉴定正确率59.37%;不同菌属及不同种的鉴定正确率有差别，气单胞菌和沙门菌较好；提取法鉴定沙门菌和气单胞菌的正确率明显高于直接涂抹法(P<0.05)。结论 MALDI-TOF MS技术鉴定腹泻病原菌具有简单、快速、部分准确的优越性，需要扩充菌种库并结合生化及血清学鉴定。     

金黄色葡萄球菌、大肠杆菌O157、普通变形杆菌和副溶血弧菌多重PCR检测体系的构建

目的:建立一个多重PCR体系,能够快速、准确地检测出食品中金黄色葡萄球菌、大肠杆菌O157、普通变形杆菌、副溶血弧菌4种食源性致病菌。方法:针对4种致病菌的特异基因设计特异性引物,建立多重PCR反应体系,并对反应体系进行了优化。结果:利用所建立的反应体系对人工染菌的海产品进行目标菌检测,该体系能同时扩增出4种目标基因片段,具有良好的特异性,对4种目标菌的检测灵敏度可达到103CFU/ml。结论:本研究建立的多重PCR体系能够快速、准确地检测食品中的金黄色葡萄球菌、大肠杆菌O157、普通变形杆菌和副溶血性弧菌,具有较好的实用性。     

2007—2008年北京大学深圳医院急性感染性腹泻细菌病原学监测结果分析

目的了解2007年7月至2008年7月间北京大学深圳医院急性感染性腹泻的流行病学特征。以便及时采取措施以防传染病暴发流行。方法选择每日排便≥3次的患者作为研究对象,在患者未使用抗菌药物之前进行大便细菌病原学检验并进行统计分析。结果共检测1017份标本,检出病原菌133株,阳性率为13．07％。133株病原菌中,致病性大肠埃希菌、副溶血弧菌、产毒大肠埃希菌、侵袭性大肠埃希菌、沙门菌分别分离出43株（32．34％）、37株（27．82％）、19株（14．28％）、18株（13．54％）和13株（9．77％）。夏秋季检出肠道致病菌90株（67．66％）,高于春冬季节的43株（32．34％）。结论不仅要针对各病原菌检出率的差异在不同季节开展相应的防控措施,还要结合地域的特点对特定的病原菌进行重点监测。     

北京地区多重耐药的腹泻病原菌的构成及耐药特点

目的 感染性腹泻是全球性的公共卫生问题，三代头孢菌素(third-generation cephalosporins, TGCs)是严重腹泻患者的首选治疗，监测医院与腹泻有关耐TGCs的腹泻病原菌的增长趋势和耐药特点，为本地区的流行病学研究及临床合理用药提供依据。方法 收集北京地区的传染病医院2011～2020年腹泻患者大便标本进行培养，筛选致病菌经生化及血清学进一步鉴定到种或群，并以纸片扩散法测定抗菌药物的敏感性；分析耐TGCs的腹泻病原菌的特点。结果 10年间共分离出沙门菌、志贺菌、气单胞菌、类志贺毗邻单胞菌、大肠埃希菌和弧菌等腹泻病原菌2 111株，其中268株耐TGCs,占整个肠道致病菌的12.70%,产生率由2011年的2.71%上升至2020年的29.29%,以致泻大肠埃希菌(39.57%)和气单胞菌(21.55%)最高，对四代头孢菌素、氟喹诺酮类、氯霉素、复方新诺明的耐药率在29%～83%,对磷霉素的耐药率最低8.27%。耐TGCs常表现多重耐药，同时耐喹诺酮类、氯霉素、复方新诺明3类抗生素为主。结论 耐TGCs的腹泻病原菌上升迅速，耐药广泛，不同种属的耐药性不同，应加强...     

重症监护室6400例血培养病原菌分布及药敏分析

目的对重症监护室6400例血培养的病原菌进行分离,并对菌株的分布及药敏进行分析。方法回顾调查2011年1月至2013年6月高州市人民医院ICU病房6400例患者的血样标本,并对其病原菌种类进行分离。采用BDBACTECTM9120全自动血培养仪对血液进行培养,BD—Phoenix-100全自动细菌鉴定仪对细菌的种类进行鉴定并对细菌的药敏性进行检测。结果6400例血样中共检出细菌971株,阳性率为15．17％。其中革兰阴性菌检出515株,占53．04％;革兰阳性菌425株,占43．77％;真菌31株,占3．19％。检出病原菌主要为大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、表皮葡萄球菌、肺炎克雷伯菌以及肠球菌等。其中,葡萄球菌对于甲氧西林和青霉素的耐药性最大,大肠埃希菌、肺炎克雷伯菌以及铜绿假单胞菌对亚胺培南都有很好的受药性。结论阴性葡萄球菌、鲍曼不动杆菌等在重症监护室中属于多发常见的病原菌,该种菌的耐药性以及多重耐药性都非常普遍,临床上应根据药敏检测结果进行用药。     

北京大型社区成人感染性腹泻肠道致病菌监测与耐药性分析

目的了解北京大型社区成人感染性腹泻的致病菌与耐药性,为肠道传染病防控和临床合理使用抗菌药提供依据。方法回顾性分析北京某大型社区2015年至2018年连续4年的4月至10月期间1847例成人肠道门诊腹泻的肠道致病菌和药敏数据。Vitek2 Compact全自动微生物鉴定药敏分析系统进行细菌鉴定,凝集试验进行血清分型,K.B纸片扩散法测定抗菌药物敏感性。结果2015年至2018年肠道致病菌检出率约12.3%,前4位的致病菌分别为副溶血弧菌(51.5%)、沙门菌属(16.3%)、气单胞菌属(11.4%)和类志贺邻单胞菌(7.0%)。肠道致病菌主要检出于7月和8月两个月,沙门菌属易高发于5月。副溶血弧菌、气单胞菌属对氨苄西林耐药率高外,对其他抗菌药均较敏感。但沙门菌属的耐药性偏高,环丙沙星敏感率为62.2%,头孢曲松耐药率10.8%。结论本地区感染性腹泻患者的致病菌主要为副溶血弧菌,而沙门菌属耐药性高,应加强感染性腹泻肠道病原菌及耐药性的监测,指导传染病防控和临床治疗。     

无锡市2009年副溶血性弧菌脉冲场凝胶电泳分型研究

目的分析无锡市2009年副溶血性弧菌分子特征,以及细菌性食物中毒分离的菌株与菌株之间、食源性疾病监测分离的副溶血性弧菌之间的遗传相关性,建立无锡地区副溶血性弧菌分子分型数据库,为无锡市进行食源性疾病的快速反应和预警、监测和控制提供科学依据。方法脉冲场凝胶电泳（PFGE）对菌株进行分子分型,所得结果以BioNumericsV4.0软件UPGMA方法进行聚类分析。结果 21株菌以SfiⅠ酶切后可分为9个PFGE型别,各群间相似性系数〉60%。其中有两起食物中毒菌株DNA指纹图谱完全相同,食源性疾病监测分离株分属7个型别。3型和6型为全年的优势型别。结论 3型和6型为无锡市2009年副溶血性弧菌优势型别,需加强防范。     

Predominant Staphylococcus aureus isolated from antibiotic-associated diarrhea is clinically relevant and produces enterotoxin A and the bicomponent toxin LukE-lukD

Staphylococcus aureus was isolated as the predominant or only isolate from cultures of stools of 60 patients over 2 years in a university hospital, leading to the collection of 114 isolates. Diarrhea was observed in 90% of the patients. Ninety-eight percent of the patients had received antibiotics in the month before the diarrhea. Ninety-two percent of the S. aureus isolates were methicillin resistant. S. aureus was encountered with antibiotic-associated diarrhea among 47 quite elderly patients affected or not affected by a gastrointestinal disease. Among the antimicrobial treatments, cessation of the previous therapy when possible or rapid application of oral vancomycin therapy was the most appropriate. Analysis of total DNA by pulsed-field gel electrophoresis revealed 27 different SmaI pulsotypes distributed in 15 clusters. The pulsotypes never differed for related isolates from a single patient, even if they originated from patients with bacteremia. S. aureus was not isolated as the predominant isolate in cultures of stools of 57 patients who received an antimicrobial treatment for more than 5 days without diarrhea. Occurence of production of both enterotoxin A and the bicomponent leucotoxin LukE-LukD by the S. aureus isolates was significantly different from that by random isolates. The results strongly suggest that when predominant in stool samples, S. aureus should be considered a possible etiologic agent for some cases of antibiotic-associated diarrhea.     

惠州市区腹泻病人沙门菌感染水平研究

目的了解和掌握惠州市区腹泻患者沙门菌感染情况及菌型分布。方法采集定点医院就诊的腹泻患者粪便标本,采用传统方法与荧光定量PCR方法相结合检测沙门菌,用SPSS17.0软件对数据进行统计分析。结果 2472例腹泻患者中,检出沙门菌44例,阳性率为1.78%,共分离出7种血清型,其中鼠伤寒沙门菌26株,斯坦利沙门菌7株,肠炎沙门菌5株,雷根特沙门菌、德尔卑沙门菌各2株,乙型副伤寒沙门菌、阿贡纳沙门菌各1株。结论惠州市区腹泻患者主要以鼠伤寒沙门菌、斯坦利沙门菌和肠炎沙门菌感染引起的腹泻为主。通过加强对腹泻门诊腹泻患者沙门菌的监测,为防止食源性疾病的发生和控制起到良好的预警作用。     

江门市某公司诺如病毒性肠炎暴发的调查

目的查明2007年江门市某公司一起诺如病毒引起的肠炎的流行特点,探讨暴发疫情调查处理的经验,为今后控制类似疫情提供科学依据。方法由疾控中心专业人员用专门的个案调查表对所有病例进行流行病学调查,部分病例采集大便样本进行检测,并结合实验室结果进行流行病学分析。结果本次疫情由诺如病毒引起,呈腹痛、腹泻等胃肠炎症状,病情较轻,共有71人发病,罹患率为7．68％,病例主要分布在30～39岁年龄段,集中在集装箱厂内的总装部和完工部。结论本次疫情通过日常生活的密切接触相互感染．经及时落实各项相应防控措施后迅速得到控制。     

武汉社区腹泻病人粪便中致病菌的构成与耐药性研究

目的了解夏秋季武汉社区引起腹泻病原菌的流行性及耐药状况。方法收集2004年7月1日至10月31日武汉社区4所大型医院4536份门诊腹泻病人粪便标本进行鉴定及药敏试验;REP-PCR对主要致病菌进行基因分型。结果4536份粪便标本中,分离出非伤寒沙门菌64株（1.4%）,志贺菌29株（0.6%）,致病性大肠杆菌33株（0.7%）。其中主要致病菌是鼠伤寒沙门菌33株（52%）,D群志贺菌16株（55%）。挑选13种抗菌药物进行体外敏感试验,并将分离的致病菌对这13种抗生素的耐药率﹑敏感率﹑中介率进行比较,其中非伤寒沙门菌对喹诺酮类的耐药率较其他两种要高,但对第三代头孢的敏感性较强。分离的3种致病菌在第三代头孢抗生素的作用中对头孢他啶的敏感性最强。32株鼠伤寒沙门菌基因分型为9种,16株D群志贺菌基因分型为7种。结论武汉社区内感染性腹泻的致病菌主要以非伤寒沙门菌﹑致病性大肠杆菌和志贺菌为主,其中非伤寒沙门菌占了51%,基因分型提示有社区流行趋势,而且这些致病菌对肠道杆菌常用抗生素的耐药性较为严重。本次调查结果对该社区临床用药起到一定的提示作用。     

Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.

In order to make a rapid and definite diagnosis of Salmonella enteritis in children, an enrichment broth culture-multiplex PCR combination assay was devised to identify Salmonella serovars directly from fecal samples. Two pairs of oligonucleotide primers were prepared according to the sequences of the chromosomal invA and plasmid spvC genes. PCR with these two primers would produce either one amplicon (from the invA gene) or two amplicons (from the invA and spvC genes), depending on whether or not the Salmonella bacteria contained a virulence plasmid. The fecal sample was diluted 10- to 20-fold into gram-negative enrichment broth and incubated to eliminate inhibitory compounds and also to allow selective enrichment of the bacteria. One or two amplicons were obtained, the expected result if Salmonella bacteria were present. The detection limit of this PCR was about 200 bacteria per reaction mixture. The primers were specific, as no amplification products were obtained with 18 species and 22 isolates of non-Salmonella bacteria tested which could be present in the feces or cause contamination. In contrast, when 23 commonly seen Salmonella serovars (38 isolates) were tested, all were shown to carry the invA gene and seven concomitantly harbored the spvC gene of the virulence plasmid. This assay was applied to the diagnosis of Salmonella enteritis in 57 children who were suffering from mucoid and/or bloody diarrhea. Of the 57 children, 38 were PCR positive and 22 were culture positive. There were two culture-positive samples that were not detected by PCR. Thus, this PCR assay showed an efficiency of 95% (38 of 40), which is much higher than the 60% (24 of 40) by culture alone. Not only is this method more sensitive, rapid, and efficient but it will cause only an incremental increase in the cost of stool processing, since enrichment cultivation of fecal samples from diarrheal patients using gram-negative enrichment broth is a routine practice for identification in many diagnostic microbiology laboratories. This PCR method, therefore, has clinical application.     

Two-year survey of etiologic agents of diarrheal disease at San Lazaro Hospital, Manila, Republic of the Philippines.

The prevalence of bacterial pathogens and rotavirus in 2,908 patients with diarrhea who were admitted to San Lazaro Hospital in Manila in 1983 and 1984 was determined. One or more enteric pathogens were isolated or detected in samples from 1,698 (58.4%) patients. Isolation rates for the various enteropathogens were as follows: rotavirus, 30.6%; Shigella spp., 11.6%; Salmonella spp., 9.2%; enterotoxigenic Escherichia coli (1983 only), 7.8%; Vibrio cholerae biotype eltor, 3.8%; non-O1 V. cholerae, 2.8%; Vibrio parahaemolyticus, 1.7%; other Vibrio spp., 1.1%; Campylobacter jejuni, 3.0%; Aeromonas hydrophila, 1.3%; and Plesiomonas shigelloides 1.1%. Giardia lamblia and Entamoeba histolytica were detected in 0.6 and 0.1%, respectively, of stool samples examined. Determination of the etiologic role of isolates was complicated by one or more of the following factors: isolation of multiple enteric pathogens (302 cases); isolation of Salmonella spp., enterotoxigenic E. coli, and C. jejuni from a similar proportion of asymptomatic control patients and patients with diarrhea; and isolation of a high proportion of certain pathogens (especially Salmonella spp.) only from enrichment broth, suggesting infection with a small number of organisms. Isolation of V. cholerae eltor was seasonal, with the majority of cases occurring in the rainy months. In addition, the number of patients with diarrhea increased with the onset of the monsoon rains and peaked during the months of maximum rainfall. Rotavirus infection occurred in both children and adults throughout the year and was the most frequently identified cause of diarrhea in children under 5 years of age. Shigella spp. were the most common agents of diarrhea in adults.     

The role of Proteae in diarrhea

A survey was undertaken on the occurrence of Protease in the human fecal flora and its coincidence with other well-documented enteropathogens such as Campylobacter, Salmonella, Shigella, Staphylococcus aureus, Yersinia, protozoa and rotavirus. A total of 2000 fecal specimens was investigated, 1000 from patients suffering from diarrhea and 1000 from healthy persons which served as controls. Proteus mirabilis was isolated more frequently from diarrhea cases than from healthy people. The difference was statistically significant (P less than 0.001). There was no correlation between its occurrence and isolation of Campylobacter, Salmonella, Shigella, Staphylococcus aureus, and protozoa. However, a questionable coincidence was found with rotavirus (P less than 0.2) and a more certain correlation with Yersinia enterocolitica (P less than 0.025). Proteus mirabilis in patients suffering from infection by other known enteropathogens was largely absent, suggesting that the organisms were independent causative agents of intestinal disorders. Notwithstanding this, they may additionally play a role as opportunists in enteric diseases due to some other pathogens.     

Molecular population genetic analysis of Staphylococcus aureus recovered from cows.

Staphylococcus aureus is one of the most common causes of bovine mastitis. To estimate genetic relationships among S. aureus strains recovered from cows, 357 isolates from milk samples from worldwide localities were examined for electrophoretic variation at 13 metabolic-enzyme loci. Thirty-nine electrophoretic types which represented distinctive multilocus enzyme genotypes were identified, and nearly 90% of all isolates were assigned to one of eight clones. Genetic heterogeneity was found among organisms recovered from dairy herds from which multiple isolates were obtained, indicating that the S. aureus population in a single herd can be multiclonal. Although humans and cows shared 7 of the 39 S. aureus clones, each clone was predominantly associated with one of these host species. These results are consistent with the concept of host specialization among S. aureus clones and imply that successful transfer of bacteria between humans and cows is limited.     

Salmonella enterica serovar Senftenberg human clinical isolates lacking SPI-1

Nontyphoidal Salmonella species cause gastrointestinal disease worldwide. The prevailing theory of Salmonella enteropathogenesis is that bacterial invasion of the intestinal epithelium is essential for virulence and that this requires the virulence-associated genomic region Salmonella pathogenicity island 1 (SPI-1). Recent studies of Salmonella enterica infection models have demonstrated that enterocolitis and diarrhea in mice and cows can occur independently of SPI-1. In this study, we sought to confirm whether two S. enterica serovar Senftenberg clinical isolates lacked genes essential for SPI-1 function. Two clinical strains were isolated and identified as being S. enterica serovar Senftenberg from four stool samples from a food-borne disease outbreak affecting seven individuals in Shenzhen, Guangdong Province, China, using conventional methods, pulsed-field gel electrophoresis and multilocus sequence typing. The possibility of coinfection with other potential bacteria or usual viruses was excluded. Two isolates were analyzed for the presence of invA, sipA, ssaR, sifA, and sopE2 by PCR and Southern blotting and were then assayed for the presence of SPI-1 by PCR and long-range PCR for fhlA-hilA, hilA-spaP, and spaP-invH and Southern blot analysis. A long-range PCR fragment from fhlA to mutS covering the 5' and 3' flanks of SPI-1 was also amplified from the two clinical isolates and sequenced. In addition, the two clinical isolates were assayed for enteroinvasiveness in vitro. Murine infection models were also examined. Biochemical tests and serotyping confirmed that the two clinical isolates are S. enterica serovar Senftenberg. However, they lacked genes critical for SPI-1 function but contained SPI-2 genes and were attenuated for the invasion of cultured intestinal epithelial cells. In conclusion, clinical S. enterica serovar Senftenberg strains isolated from a food-borne disease outbreak lack the invasion-associated locus SPI-1, indicating that SPI-1 is not essential for human gastroenteritis.     

Diarrhea in children under 5 years of age from Ifakara, Tanzania: a case-control study

A matched case-control study was conducted in the Maternal and Child Health Clinic (MCH) in Ifakara, Tanzania, during the rainy season in order to elucidate the risk factors for and etiology of diarrheal diseases in children under 5 years of age. Cases (103) and controls (206) were matched for sex and age group. Precoded questionnaires with demographic details, clinical history, and physical signs were completed. Stools samples were collected for bacterial, parasitological, and viral studies. A high number of siblings (odds ratio [OR], 0.86; P = 0.027), the number of siblings surviving (OR, 0.82; P = 0.007), the birth order (OR, 0.85; P = 0.018) and the distance from the house to the water source (OR, 0.33; P = 0.011) were associated with the risk of diarrhea. There were high rates of enteropathogen isolates in stool samples from children without diarrhea (52.23%). Shigella species were the only enteropathogen statistically related with diarrhea (OR, 2.90; P < 0.029). Enterotoxigenic, enteropathogenic, and enteroaggregative strains of Escherichia coli were not related with diarrhea, and neither were Giardia lamblia or Salmonella species.