OBJECTIVETo elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China.

METHODSA total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing.

RESULTSAmong 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions.

CONCLUSIONThe results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Animals ; Anti-Bacterial Agents ; pharmacology ; Cefotaxime ; pharmacology ; Chickens ; microbiology ; China ; Ciprofloxacin ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Food Contamination ; Food Microbiology ; Meat ; microbiology ; Salmonella ; classification ; isolation & purification ; Serotyping ; beta-Lactamases

This study was conducted to analyze the prevalence and quantitative loads of Salmonella spp. on pig farms in Chiang Mai, Lamphun, Thailand to assess loading levels before slaughtering. The serotype diversity, antimicrobial-resistance pattern and pulse-field type of Salmonella spp. were also characterized to assess the dynamic propagation of the pathogen. The Salmonella-positive prevalence was 246/805 (30.56%), and the quantitative loads varied from 1.48~4.04 Log10MPN/g, with a mean +/- standard deviation of 2.11 +/- 0.57. AMP/S/TE (ampicillin/streptomycin/tetracycline) was the highest frequency antimicrobial resistance pattern found in this study. In addition, Salmonella Rissen was the primary serotype in this region. PFGE results indicated the occurrence of infection by cross contamination among pig farms. Our study showed that pork is easily contaminated with this pathogen. Farm control programs must be based on strict biosecurity and hygienic measures, which could further reduce the contamination pressure at slaughterhouses or retail shops.
Abattoirs ; Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Load/veterinary ; Colony Count, Microbial/veterinary ; Drug Resistance, Multiple, Bacterial/*drug effects ; Electrophoresis, Gel, Pulsed-Field/veterinary ; Feces/microbiology ; Female ; Male ; Prevalence ; Salmonella/classification/*drug effects/*genetics/isolation & purification ; Salmonella Infections, Animal/*epidemiology/microbiology/transmission ; Serotyping/veterinary ; Swine ; Swine Diseases/*epidemiology/microbiology/transmission ; Thailand/epidemiology

OBJECTIVETo determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.

METHODSFive large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.

RESULTSIn total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.

CONCLUSIONOur findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.

Animals ; Chickens ; microbiology ; China ; Drug Resistance, Multiple, Bacterial ; Food Contamination ; Meat-Packing Industry ; Salmonella ; classification ; drug effects ; isolation & purification ; Serotyping

OBJECTIVETo 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.

METHODSOn 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.

RESULTSChildren 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.

CONCLUSIONIt 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.

Bacteriophage Typing ; Child, Preschool ; China ; epidemiology ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Female ; Humans ; Male ; Molecular Epidemiology ; Salmonella Food Poisoning ; epidemiology ; microbiology ; Salmonella enteritidis ; classification ; isolation & purification

OBJECTIVEIn order to better understand the nature of Salmonella infection in diarrheal patients in Guangdong province, the study analyzed the serum types, antibiotic resistance and molecular determinants of the isolated Salmonella strains.

METHODSIn year 2010, 8405 diarrhea patients from 16 surveillant hospital in Guangzhou, Zhongshan, Dongguan, Zhuhai, Maoming, Yangjiang and Jiangmen cities in Guangdong province, were recruited in the study. A total of 8405 fecal specimen were collected and subjected to Salmonella isolation and culture. The isolated Salmonella strains were further analyzed via serotyping, antimicrobial susceptibility testing, and PFGE. The χ(2) test was applied to compare the differences between the isolated Salmonella strains in different seasons and districts. BioNumerics software was used to analyze the PFGE results in order to determine the correlation between different Salmonella strains.

RESULTSThe positive rate of the surveillant Salmonella in Guangdong province was 3.58% (301/8405) in 2010; with the gender ratio at 1.34:1 (166/124). Salmonella infection was found in all age groups, and most in infants, accounting for 57.48% (173/301). The isolated rates of Salmonella were separately 3.48% (61/1751), 4.97% (134/2695), 3.08% (73/2370) and 2.08% (33/1589) in the four seasons; and the difference was statistically significant (χ(2) = 27.29, P < 0.01). The isolated rates of Salmonella in different regions were as follows: Zhuhai 15.43% (25/162), Maoming 7.53% (18/239), Dongguan 6.51% (39/599), Yangjiang 3.64% (14/385), Zhongshan 3.03% (70/2309), Guangzhou 2.90% (126/4349) and Jiangmen 2.49% (9/362). The difference between regions was statistically significant (χ(2) = 100.75, P < 0.01). Except one strain of the isolated Salmonella cannot be serotyped, the other 300 strains were divided into 42 serotypes, of which Salmonella typhimurium and Salmonella enteritidis were dominant, account for 45.18% (136/301) and 10.96% (33/301) respectively. Although over 85% of Salmonella were sensitive to cephalosporin, ACSSuT resistance patterns (defined as resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) reached 34.88% (105/301), the highest resistant rate was found in serotype Salmonella typhimurium, as high as 65.44% (89/136). 136 strains of Salmonella typhimurium were divided into 51 PFGE types, showed great genetic diversity. 33 strains of Salmonella enteritidis were divided into 18 PFGE types. The strains with same PFGE pattern may have different drug-resistant patterns, and vice versa.

CONCLUSIONSalmonella typhimurium and Salmonella enteritidis were the dominant serotypes causing infectious diarrhea in Guangdong province. Cephalosporin was the primary choice in clinical medicine. However, Salmonella typhimurium was resistant to drug most seriously in Guangdong province. There was no significant correlation between Salmonella resistance patterns and PFGE type.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; Bacterial Typing Techniques ; Child ; Child, Preschool ; China ; epidemiology ; Diarrhea ; microbiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Salmonella Infections ; epidemiology ; microbiology ; prevention & control ; Salmonella enteritidis ; classification ; isolation & purification ; Salmonella typhimurium ; classification ; isolation & purification ; Serotyping ; Young Adult

OBJECTIVETo study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009.

METHODSA total of one hundred thirty-seven isolates recovered from the WHO Global Salmonella 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.

RESULTSThe 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, JEGX01.CN0002, JEGX01.CN0019) and S. Typhimurium pattern of JPXX01.CN0001 were dominant patterns.

CONCLUSIONThe 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.

Adolescent ; Adult ; Bacterial Typing Techniques ; China ; epidemiology ; DNA, Bacterial ; isolation & purification ; Electrophoresis, Gel, Pulsed-Field ; Female ; Food Microbiology ; Humans ; Male ; Molecular Typing ; Salmonella ; classification ; genetics ; isolation & purification ; Salmonella Infections ; epidemiology ; microbiology ; Serotyping ; Young Adult

OBJECTIVETo analyze molecular and evolution characteristics of Salmonella Paratyphi A isolates from 2000 to 2008, China.

METHODSUsing pulsed-field gel electrophoresis (PFGE) method with SpeI restriction enzyme, and multilocus sequence typing (MLST) method based on housekeeping genes (aroC, thrA, hisD, purE, sucA, dnaN, hemD, adk, and purA), the genomic variations of 118 Salmonella Paratyphi A isolates from 10 regions during 2000 to 2008 were analyzed.

RESULTSUsing PFGE method, 118 Salmonella Paratyphi A isolates were clustered into 32 PFGE patterns, and 5 patterns were predominant (5 isolates or above). However, only 2 MLST types were identified for all isolates with MLST method. Among all Salmonella Paratyphi A isolates, the sequences of housekeeping genes were highly conservative and showed a high degree of cloning.

CONCLUSIONFor Chinese epidemic Salmonella Paratyphi A isolates during 2000 - 2008, MLST method showed low discrimination power and the MLST method should not be applied to outbreak and epidemiological surveillance of Salmonella Paratyphi A. Currently, nationwide paratyphoid fever epidemics is caused by highly clonal isolates in China. As the time changes, these isolates also accumulate sporadic mutations.

Bacterial Typing Techniques ; China ; DNA, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; methods ; Humans ; Multilocus Sequence Typing ; Paratyphoid Fever ; epidemiology ; microbiology ; Salmonella paratyphi A ; classification ; genetics ; isolation & purification ; Sequence Analysis, DNA ; Serotyping

Salmonella enterica has been one of the most widespread foodborne pathogens in Korea. Between 1998 and 2007, a total of 9,472 Salmonella isolates were identified from foodborne and waterborne illness patients. During that time, Korea was transitioning into a developed country in industry as well as in its hygiene system. Although the isolation number of total Salmonella including serovar Typhi has decreased since 1999, the isolation of rare Salmonella serovars has emerged. Three most prevalent serovars during 1998-2007 were S. enterica Typhi, S. enterica Enteritidis, and S. enterica Typhimurium. There were remarkable outbreaks caused by rare serovars such as S. enterica Othmarschen, S. enterica London and S. enterica Paratyphi A, and overseas traveler-associated infections caused by S. enterica Weltevreden and S. enterica Anatum. Salmonella serovars from overseas travelers made a diverse Salmonella serovar pool in Korea. This study is the first review of the status of the human Salmonella infection trend in a developing country during 1998-2007. Newly emerging rare Salmonella serovars should be traced and investigated to control new type pathogens in the developed world.
Food Microbiology ; Humans ; Republic of Korea ; Salmonella/classification/genetics/*isolation & purification ; Salmonella Infections/epidemiology/etiology/*microbiology ; Serotyping ; Water Microbiology

OBJECTIVETo understand pathogen patterns of enteric infectious diseases and its impact on this pattern due to aggregation of a great deal of foreign visitors during Beijing Olympic Games.

METHODSThe diarrheal patient's rectal swabs and stool specimens were collected from Olympic stadium and hospitals of four districts, including Dongcheng, Xicheng, Haidian and Chaoyang. Enteric multiple pathogens were detected from the total 45 specimens. The culture method was used for the enteric bacteria, ELISA and RT-PCR for the enteric viruses. Molecular typing of Salmonella Enteritidis isolation was completed by PFGE.

RESULTSIt was found that 26 out of 45 cases were positive with 57.8 percent for pathogen detection, and 24 were identified as enteric pathogenic bacteria, including Vibrio parahaemolyticus, Salmonella, diarrheagenic Escherichia coli and Campylobacter jejuni, two as norovirus. There were mixed infections of two pathogenic bacteria for three cases. Ten kinds of pathogens were detected from foreign cases, while five kinds from Chinese cases. A total of 5 PFGE patterns were identified in 10 Salmonella Enteritidis isolates from national and foreign diarrheal cases, which were concentrative in some extent.

CONCLUSIONVibrio parahaemolyticus, Salmonella, diarrheagenic Escherichia coli and Campylobacter jejuni were found to be the primary bacterial pathogens during the Olympic Games. Enteric virus infection existed in summer diarrhea.

Adult ; Bacterial Typing Techniques ; Campylobacter jejuni ; classification ; isolation & purification ; China ; Diarrhea ; epidemiology ; etiology ; microbiology ; virology ; Enterobacteriaceae ; classification ; isolation & purification ; Enterovirus ; isolation & purification ; Escherichia coli Infections ; microbiology ; Female ; Humans ; Male ; Salmonella ; classification ; isolation & purification ; Shigella ; classification ; isolation & purification ; Sports ; Vibrio parahaemolyticus ; classification ; isolation & purification

OBJECTIVETo investigate the application of pulsed-field gel electrophoresis (PFGE) in food-borne outbreak.

METHODSPathogens were isolated and further characteristics identified by traditional methods. The strains isolated were carried out with molecular typing with using PFGE. PFGE was performed by Laboratory Directions for molecular subtyping of Salmonella by PFGE (CDC, USA) and the results of PFGE were analyzed by BioNumerics soft.

RESULTSTotally 14 Salmonella serotype Muenchen strains were isolated from 19 patients, 3 of 9 suspicious foods were positive for S. muenchen and 7 strains were isolated from 18 cooks. The biochemistry characterization and antimicrobial susceptibility of all the strains isolated were the same. 23 S. muenchen isolates were all shown indistinguishable by PFGE.

CONCLUSIONPFGE should play a key role in identifying the outbreak-associated isolates and distinguishing them from unrelated sporadic isolates. It might also demonstrate that the genetic fingerprints of serotype Muenchen isolates derived from patients were indistinguishable from those derived from drinks. PFGE might provide precise information on bacterial food-borne pathogens, promptly identify the source of infection, and effectively prevent from spreading. It should be one of the early warning method on controlling outbreak of the food-borne disease.

China ; epidemiology ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; methods ; Humans ; Microbial Sensitivity Tests ; Salmonella Food Poisoning ; epidemiology ; microbiology ; Salmonella enterica ; classification ; isolation & purification ; Serotyping