Two foodborne disease outbreaks caused by Salmonella putten

Objective To investigate the antimicrobial resistance status and pulsed field gel electrophoresis (PFGE) patterns of Salmonella enteritidis (S.enteritidis) in Shanxi Province in order to provide references for the treatment of Salmonella infection and for tracing the source of outbreaks of foodborne diseases. Methods Sixty-four S. enteritidis strains were collected by monitoring sites for foodborne diseases from April 2015 to March 2018. Biochemical identification system and serotyping analysis were used for bacterial identification. Drug susceptibility patterns were analyzed with micro-broth dilution method. PFGE was used for molecular typing. Results The antimicrobial resistance rate of 64 S. enteritidis strains to nalidixic acid (95.31%) was the highest, followed by that to ampicillin (90.63%) and to ampicillin/sulbactam (81.25%). They had lower resistance rates to cefazolin, cefotaxime, tetracycline, ceftazidime, trimethoprim/sulfamethoxzole and ciprofloxacin (3.13%-23.44%) and were all sensitive to chloramphenicol, cefotaxime, azithromycin, imipenem and gentamicin. No statistically significant difference in drug resistance rates was found between the sporadic strains and the outbreak strains (P>0.05). All 64 S. enteritidis strains digested with XbaⅠwere divided into 33 molecular patterns by PFGE. The numbers of bacteria contained in each pattern ranged from 1 to 10 strains. The similarity among patterns was between 54.6% and 100%. Conclusion More attention should be paid to the drug resistance status of S. enteritidis in Shanxi Province. It is necessary to strengthen the standardized administration of antibiotics. The PFGE patterns of S. enteritidis reveal the presence of significant genetic polymorphism. PFGE is of great significance in analyzing the genetic relationship among S. enteritidis strains and in identifying and tracing the source of outbreaks of foodborne diseases. Key words: Salmonella enteritidis; Drug sensitivity; PFGE molecular typing

To apply a multiplex real-time polymerase chain reaction (PCR) technique to detect Salmonella spp., Listeria monocytogenes, and Yersinia enterocolitica as a diagnostic support tool for the surveillance of foodborne disease outbreaks. Molecular methodology was applied on clinical samples taken from individuals who were associated with foodborne disease outbreaks in two departments of Colombia. The results were compared with the data obtained by conventional culture methodology. In addition, the clonal relation of the isolations was evaluated using the Pulsed Field Gel Electrophoresis (PFGE) technique. 123 cases of foodborne disease were determined, of which 45 biological samples were confirmed by laboratory and 88 by epidemiological link. The molecular methodology detected 35/45 positive samples versus 17/45 positive samples detected by conventional methodology. PFGE demonstrated a clonal relation during each outbreak. The results of the study demonstrate the applicability of the molecular technique as a useful diagnostic support tool to characterize foodborne disease outbreaks, allowing a timely and reliable response.

Foodborne diseases cause an estimated 48 million illnesses each year in the United States, including 9.4 million caused by known pathogens. Foodborne disease outbreak surveillance provides valuable insights into the agents and foods that cause illness and the settings in which transmission occurs. CDC maintains a surveillance program for collection and periodic reporting of data on the occurrence and causes of foodborne disease outbreaks in the United States. This surveillance system is the primary source of national data describing the numbers of illnesses, hospitalizations, and deaths; etiologic agents; implicated foods; contributing factors; and settings of food preparation and consumption associated with recognized foodborne disease outbreaks in the United States.1998-2008.The Foodborne Disease Outbreak Surveillance System collects data on foodborne disease outbreaks, defined as the occurrence of two or more cases of a similar illness resulting from the ingestion of a common food. Public health agencies in all 50 states, the District of Columbia, U.S. territories, and Freely Associated States have primary responsibility for identifying and investigating outbreaks and use a standard form to report outbreaks voluntarily to CDC. During 1998-2008, reporting was made through the electronic Foodborne Outbreak Reporting System (eFORS).During 1998-2008, CDC received reports of 13,405 foodborne disease outbreaks, which resulted in 273,120 reported cases of illness, 9,109 hospitalizations, and 200 deaths. Of the 7,998 outbreaks with a known etiology, 3,633 (45%) were caused by viruses, 3,613 (45%) were caused by bacteria, 685 (5%) were caused by chemical and toxic agents, and 67 (1%) were caused by parasites. Among the 7,724 (58%) outbreaks with an implicated food or contaminated ingredient reported, 3,264 (42%) could be assigned to one of 17 predefined commodity categories: fish, crustaceans, mollusks, dairy, eggs, beef, game, pork, poultry, grains/beans, oils/sugars, fruits/nuts, fungi, leafy vegetables, root vegetables, sprouts, and vegetables from a vine or stalk. The commodities implicated most commonly were poultry (18.9%; 95% confidence interval [CI] = 17.4-20.3) and fish (18.6%; CI = 17.2-20), followed by beef (11.9%; CI = 10.8-13.1). The pathogen-commodity pairs most commonly responsible for outbreaks were scombroid toxin/histamine and fish (317 outbreaks), ciguatoxin and fish (172 outbreaks), Salmonella and poultry (145 outbreaks), and norovirus and leafy vegetables (141 outbreaks). The pathogen-commodity pairs most commonly responsible for outbreak-related illnesses were norovirus and leafy vegetables (4,011 illnesses), Clostridium perfringens and poultry (3,452 illnesses), Salmonella and vine-stalk vegetables (3,216 illnesses), and Clostridium perfringens and beef (2,963 illnesses). Compared with the first 2 years of the study (1998-1999), the percentage of outbreaks associated with leafy vegetables and dairy increased substantially during 2006-2008, while the percentage of outbreaks associated with eggs decreased.Outbreak reporting rates and implicated foods varied by state and year, respectively; analysis of surveillance data for this 11-year period provides important information regarding changes in sources of illness over time. A substantial percentage of foodborne disease outbreaks were associated with poultry, fish, and beef, whereas many outbreak-related illnesses were associated with poultry, leafy vegetables, beef, and fruits/nuts. The percentage of outbreaks associated with leafy vegetables and dairy increased during the surveillance period, while the percentage associated with eggs decreased.Outbreak surveillance data highlight the etiologic agents, foods, and settings involved most often in foodborne disease outbreaks and can help to identify food commodities and preparation settings in which interventions might be most effective. Analysis of data collected over several years of surveillance provides a means to assess changes in the food commodities associated most frequently with outbreaks that might occur following improvements in food safety or changes in consumption patterns or food preparation practices. Prevention of foodborne disease depends on targeted interventions at appropriate points from food production to food preparation. Efforts to reduce foodborne illness should focus on the pathogens and food commodities causing the most outbreaks and outbreak-associated illnesses, including beef, poultry, fish, and produce.

Objective To analyze the pulse-field gel electrophoresis (PFGE) patterns and antibiotic resistance of Salmonella enteritidisstrains isolated in Longyan city in order to provide reference for effective control, clinical diagnosis and treatment of outbreaks of food-borne diseases. Methods Seventy-seven Salmonella enteritidis strains isolated from food poisoning cases, livestock and poultry meat samples collected for food safety risk monitoring and sporadic cases in 2014 and 2016 were analyzed by PFGE. Antibiotic susceptibility testing was carried out to determine the minimum inhibitory concentrations (MIC) of 16 common antibiotics to 57 strains. Results Seventeen PFGE types were identified among the 77 Salmonella strains including three predominant types (P4, P6 and P8) and were grouped into three major pulsotypes (Cluster1-3) at 90% similarity level. The predominant types causing outbreaks of Salmonella enteritidis infection were P8, P6, P4 and P14, which were responsible for five cases of food poisoning.These isolated strains were highly resistant to nalidixic acid (93%), followed by resistance towards ampicillin (74%) and streptomycin (54%). Forty-one strains were resistant to three or more antibiotics (71.93%). Conclusion The PFGE types of Salmonella enteritidis strains isolated in Longyan city exhibit polymorphism and are clustered into three major pulsotypes. PFGE molecular typing can provide early-warning of sporadic outbreaks and help to identify the sources of infections in Salmonella enteritidis-related food poisoning. Attentions should be paid to multidrug resistant Salmonella enteritidis. Surveillance for multidrug resistant strains and usage of antibiotics should be strengthened. Key words: Salmonella enteritis; PFGE molecular typing; Cluster analysis; Minimum inhibitory concentration; Multidrug resistance

Salmonella can cause food poisoning and food-borne disease outbreaks,which is a significant global public health problem.The serotype of salmonella isolated from human infection,and the PFGE molecular typing of Salmonella strains with the same serotype,can enhance the ability of identifying food-borne disease outbreaks,detect cases and trace the source of infection.In the article,the advance of Samondla serotype and PFGE molecular typing and its apphcation are reviewed. Key words: Samonella; Serotype; Outbreak; Pulsed field gel electrophoresis; PulseNet

Background: Foodborne diseases are still a major health issue in Lebanon, although some steps have been taken forward in food safety. To this purpose, PulseNet Lebanon, a foodborne diseases tracking network, was established in 2009, through the collaboration between the Ministry of Public Health (MoPH) and the American University of Beirut (AUB).Materials and Methods: Three papers published regarding the PulseNet project were summarized. Initially, clinical and food samples, collected within the surveillance network scope, were identified by using the respective API for Salmonella and Listeria spp. Salmonella spp. were further serotyped by using the Kauffman and White method. Campylobacter spp. were determined by the 16 S rRNA sequencing method. Antimicrobial susceptibility to a number of antibiotics was determined by using the disk diffusion method for Samonella and Campylobacter spp. Genomic diversity was determined by using pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD).Results: Results indicated that 290 clinical and 49 food isolates were identified as Salmonella. Serotyping revealed the prevalence of ten and seven serotypes in the clinical and food samples, respectively. Fifty-one isolates from chicken ceca and carcass were identified to be Campylobacter spp. Fifty-nine samples were identified to be Listeria monocytogenes. Antimicrobial susceptibility testing revealed a wide range of resistance among the different samples. PFGE showed a variation in pulsotypes among the Salmonella serotypes. PFGE also linked certain outbreaks to their food sources. This method also demonstrated 13 subtypes with 100% similarity among the L. monocytogenes isolates. Finally, the Camplyobcater spp. were grouped into nine clusters with a minimum similarity of 43.5% using RAPD.Conclusion: This summary of results shows the importance of implementing a “farm-to-fork” approach in the surveillance of foodborne disease outbreaks in Lebanon, allowing the detection of pathogens causing foodborne disease outbreaks in a timely fashion.

Objective To analyze the epidemiological characteristics of school foodborne disease outbreaks in Henan Province from 2011 to 2020 and to provide the basis for effective prevention and control of school foodborne disease outbreaks. Methods The outbreaks of foodborne diseases in schools in Henan Province reported by the foodborne disease outbreak surveillance system from 2011 to 2020 were statistically analyzed. Results A total of 47 outbreaks of school foodborne diseases were reported in Henan province in the past 10 years, with a total of 1 258 cases, 701 hospitalizations and 1 death. Zhengzhou, Zhumadian, Xinyang and Xinxiang were the top 4 cities in Henan Province in terms of the number of school foodborne disease outbreaks reported. The peak of foodborne illness incidents in schools was in June and September. The largest number of incidents occurred in middle school canteens and primary school canteens (all 12). The number of reported incidents (12) and the number of cases of foodborne diseases (371) in schools caused by cereals and their products were the largest. Pathogenic bacteria and their toxins were the main pathogenic factors that caused the outbreaks of foodborne diseases in schools, accounting for 78.26% of the identified causes. Bacillus cereus was the top pathogens causing foodborne diseases outbreaks in schools. The pathogenic factor that caused the largest number of cases was Diarrheogenic Escherichia Coli, and the pathogenic factor that caused the death cases was poisonous mushrooms. Apart from unexplained incidents, improper processing was the main link leading to foodborne diseases outbreaks in schools. Conclusion The primary and middle school students are the group with high incidence of foodborne diseases in schools. The supervision and management of school canteen should be strengthened in summer to prevent the outbreak of bacterial foodborne diseases caused by improper processing and storage of grain food. 【摘要】 目的 分析河南省 2011—2020 年学校食源性疾病暴发事件的流行病学规律及特点, 为有效防控学校食源性疾病 暴发事件提供依据。 方法 对国家食品安全风险评估中心的食源性疾病暴发监测系统报告的 2011—2020 年河南省学校 食源性疾病暴发事件进行流行病学统计分析。 结果 河南省 10 年间共报告学校食源性疾病暴发事件 47 起, 累计发病人 数 1 258 人, 住院人数 701 人, 死亡 1 人。河南省学校食源性疾病暴发事件报告起数前 4 位的城市为郑州市、驻马店市、信 阳市, 新乡市。学校食源性疾病事件高峰期是 6 和 9 月。中学食堂和小学食堂导致的事件数最多 (均为 12 起)。粮食制品 引起的学校食源性疾病上报事件数和发病人数最多 (14 起, 371 人)。致病菌及其毒素是引起学校食源性疾病暴发事件的 主要病原因子, 占查明原因事件数的 78.26%。引起学校食源性疾病暴发事件最多的致病菌是蜡样芽孢杆菌, 引起发病人 数最多的致病因素是致泻大肠埃希菌, 引发死亡病例的致病因素是毒蘑菇。除原因不明的事件外, 加工不当是导致学校食 源性疾病暴发事件的主要环节。 结论 中小学生是学校食源性疾病高发群体, 应加强夏秋季学校食堂的监督和管理, 预防 粮食类食品加工储存不当导致的细菌性食源性疾病暴发事件。

Impacts of Microbial Food Safety in China and Beyond.

T HE NUMBER of reported outbreaks of waterborne and foodborne diseases was slightly higher in 1959 than in 1958 (table 1). There was a considerable increase in number of reported outbreaks and cases of staphylococcal food poisoning as compared with the previous year, but this was largely offset by smaller numbers in some other categories (table 2). While it seems improbable that outbreaks of foodborne diseases were more completely reported in 1959 than in previous years, there is evidence that more extensive laboratory investigations were being carried out in some areas. The number of outbreaks in which phage typing of staphylococci was done increased in 1959. In a few instances, the same phage type of organism was recovered from specimens of food as from persons who were handling or preparing foods. Phage types 7 and 47 were more commonly reported than any others. Phage type 80/81 was recovered from ham in one outbreak and from milk in another. A few reports indicated that phage typing was being done but the results of tests were not received. Introduction of coagulase-positive strains of staphylococci of human origin into herds of dairy cattle is receiving more attention. In one State antibiotic-resistant strains of phage type 80/81 were recovered from superficial lesions on the udders of cattle in a herd owned by a carrier of this type of staphylococcus. Two other adults in the family also were carriers of this type. When the animals were moved to new premises and their human contacts changed, their lesions disappeared. A similar situation was reported recently by Wallace (1). Phage type 80/81 was recovered from four cattle in a dairy herd and also from lesions on one worker at the dairy farm. One State is now conducting an intensive study of staphylococcal infections in cattle and their relationship to human infections and disease. Several outbreaks of foodborne diseases were reported in 1959 in which Closttidiuim perfringens (welchii) was considered or suspected as the etiological agent. This spore-forming organism, of which one type (A) causes gas gangrene, has been recognized as the etiological agent in outbreaks in England for a number of years. Its association with disease outbreaks in the United States had been suspected but was not proved until recently. Failure to recognize the role of this organism in foodborne diseases in this country has been due partly to the fact that it can be recovered only when incubated anaerobically. The procedures required for identification of the organism are complicated, and few laboratories are equipped to perform them. C. perfringens is widely distributed in nature in feces, sewage, and soil. Outbreaks due to this bacterium are usually associated with meat, includingfowl, that has been cooked and allowed to cool slowly at room temperature. The incubation period of illnesses is about 8 to 12 hours but may be as long as 22 hours. According to Dack (2), the characteristic symptoms are acute abdominal pain and diarrhea, usually of short duration. In 1959, there were 75 outbreaks of foodborne diseases, affecting more than 1,200 persons, in which poultry or other meat was thought to be the vehicle of infection but no etiological agent was identified. Possibly some of these were caused by C. perfringens. It has Dr. Dauer is medical adviser to the chief, and Mr. Davids is health program representative, in the National Office of Vital Statistics, Public Health Service.

To conduct an etiological molecular epidemiological survey and laboratory test on a foodborne disease epidemic outbreak to make clear of the cause and implement effective prevention and control on it. On May 12th 2012, 135 kindergarten children were sent to Xuzhou City People's Hospital and Children's Hospital with gastrointestinal infection disease. A total of 34 anus swab samples and 4 vomit samples were collected from the patients. Real-time PCR rapid detection, strains separation and cultivation, phage lysis experiments, ATB automated identification system were used to make etiological detection and identification. The genomic DNA of salmonella enteritidis were typed with the pulsed-field gel electrophoresis (PFGE), cluster analysis were carried out together with the patterns of local Salmonella infections. Children in 20 classes were suffered from the gastrointestinal infection among the 21 classes. There were no significant aggregation of class distribution. Among the 135 patients, 76 were boys (56.3%) and 59 were girls (43.7%). The main symptoms were fever (above 38°C), diarrhea and bellyache. Through real-time PCR detection and strains separation, 19 salmonella enteritidis were isolated from 34 anus swab samples of suspected cases and the detection rate was 56%. There were no strains detected from vomit samples. All of the 19 salmonella enteritidis showed the same serological subtype, biochemical reaction, drug sensitivity and phage lysis pattern. The salmonella enteritidis had the identical PFGE pattern (100% similarity), and were different from the pattern of local sporadic infection cases. It was confirmed that this was an epidemic outbreak of foodborne disease caused by homologous salmonella enteritidis by epidemiological survey, clinical information, lab etiological test and molecular typing.

Molecular Subtyping and the Transformation of Public Health

BackgroundFoodborne diseases are a worldwide public health problem. However, data regarding epidemiological characteristics are still lacking in China. We aimed to analyze the characteristics of foodborne diseases outbreak from 2010 to 2016 in Guangxi, South China.MethodsA foodborne disease outbreak is the occurrence of two or more cases of a similar foodborne disease resulting from the ingestion of a common food. All data are obtained from reports in the Public Health Emergency Report and Management Information System of the China Information System for Disease Control and Prevention, and also from special investigation reports from Guangxi province.ResultsA total of 138 foodborne diseases outbreak occurred in Guangxi in the past 7 years, leading to 3348 cases and 46 deaths. Foodborne disease outbreaks mainly occurred in the second and fourth quarters, and schools and private homes were the most common sites. Ingesting toxic food by mistake, improper cooking and cross contamination were the main routes of poisoning which caused 2169 (64.78%) cases and 37 (80.43%) deaths. Bacteria (62 outbreaks, 44.93%) and poisonous plants (46 outbreaks, 33.33%) were the main etiologies of foodborne diseases in our study. In particular, poisonous plants were the main cause of deaths involved in the foodborne disease outbreaks (26 outbreaks, 56.52%).ConclusionsBacteria and poisonous plants were the primary causative hazard of foodborne diseases. Some specific measures are needed for ongoing prevention and control against the occurrence of foodborne diseases.

--To describe the epidemiology of foodborne disease outbreaks in nursing homes and to identify where preventive efforts might be focused. --Reports by state and local health departments of foodborne disease outbreaks occurring from January 1, 1975, through December 31, 1987. --Foodborne disease outbreaks reported to the Centers for Disease Control, Atlanta, Ga, on standard investigation forms. --Each foodborne disease outbreak report was examined by an epidemiologist or statistician. Outbreaks were considered to have a known pathogen if confirmed by laboratory tests, and a known vehicle when an epidemiologic investigation implicated a specific food item. --From 1975 through 1987, 26 states reported 115 outbreaks of foodborne disease in nursing homes, causing illness in 4944 persons and death in 51. These outbreaks represented 2% of all reported foodborne disease outbreaks and 19% of outbreak-associated deaths in this period. Of 52 outbreaks with a known cause, Salmonella was the most frequently reported pathogen, accounting for 52% of outbreaks and 81% of deaths. Salmonella enteritidis outbreaks accounted for 56% of the Salmonella-associated deaths since 1981. The implicated food vehicles in S enteritidis outbreaks were made with eggs or prepared with equipment contaminated with eggs. Staphylococcal foodborne disease was the next most commonly identified cause, accounting for 23% of outbreaks. --Since the elderly are at high risk for serious morbidity from foodborne disease, nursing homes should practice careful food handling, preparation, and storage procedures; provide education for food handlers; and have active infection control programs to rapidly detect and control outbreaks of foodborne disease.

Changes in food production and distribution have increased opportunities for foods contaminated early in the supply chain to be distributed widely, increasing the possibility of multistate outbreaks. In recent decades, surveillance systems for foodborne disease have been improved, allowing officials to more effectively identify related cases and to trace and identify an outbreak's source. We reviewed multistate foodborne disease outbreaks reported to the Centers for Disease Control and Prevention's Foodborne Disease Outbreak Surveillance System during 1973-2010. We calculated the percentage of multistate foodborne disease outbreaks relative to all foodborne disease outbreaks and described characteristics of multistate outbreaks, including the etiologic agents and implicated foods. Multistate outbreaks accounted for 234 (0.8%) of 27,755 foodborne disease outbreaks, 24,003 (3%) of 700,600 outbreak-associated illnesses, 2839 (10%) of 29,756 outbreak-associated hospitalizations, and 99 (16%) of 628 outbreak-associated deaths. The median annual number of multistate outbreaks increased from 2.5 during 1973-1980 to 13.5 during 2001-2010; the number of multistate outbreak-associated illnesses, hospitalizations, and deaths also increased. Most multistate outbreaks were caused by Salmonella (47%) and Shiga toxin-producing Escherichia coli (26%). Foods most commonly implicated were beef (22%), fruits (13%), and leafy vegetables (13%). The number of identified and reported multistate foodborne disease outbreaks has increased. Improvements in detection, investigation, and reporting of foodborne disease outbreaks help explain the increasing number of reported multistate outbreaks and the increasing percentage of outbreaks that were multistate. Knowing the etiologic agents and foods responsible for multistate outbreaks can help to identify sources of food contamination so that the safety of the food supply can be improved.

Foodborne diseases have become a serious public health problem worldwide, and foodborne disease outbreaks have placed a heavy disease burden on China. Foodborne disease outbreaks occur most frequently among families in China. The objectives of this study were to analyze the cause of household foodborne disease outbreaks in China from 2010 to 2020 and to identify where preventive measures could be targeted. All data were obtained from the China Foodborne Disease Surveillance System Report. A total of 17,985 outbreaks, which resulted in 73,252 illnesses, 38,829 hospitalizations, and 1269 deaths, were reported in this period. Most household outbreaks of foodborne diseases occurred in May-October, and the highest number occurred in July (3620 outbreaks, 20%). The province with the highest number of outbreaks was Yunnan Province (4829 outbreaks), followed by Hunan Province (2264 outbreaks). The attribution analysis revealed that fungi (mainly poisonous mushrooms) were the most implicated food category, with 8873 (49.3%) cases. The second was poisonous plants and their products, with 1552 (8.6%) cases. Fungi were the primary etiologic agent, with 31,125 illnesses, accounting for 42.5% of the incidents. Inedibility and misuse (9423 outbreaks), unknown origin (2505 outbreaks), and improper processing (2365 outbreaks) were the main contributing factors causing outbreaks of foodborne diseases. The results show that southwest China was a high-risk area for household foodborne diseases. Therefore, public health institutions should strengthen supervision and food safety education of residents to reduce the outbreaks of household foodborne diseases.