ABSTRACT
Diarrheagenic Escherichia coli (E. coli) is a main cause of diarrhea worldwide. This study reports the investigation on the occurrence of enterotoxigenic E. coli (ETEC) serotype O27:H7-associated foodborne gastrointestinal disease that occurred at two schools, one middle school and one high school, in Seoul, Korea in June 2015. The immediate government investigation in 1,216 students and 19 food handlers in these two schools revealed that 116 students, 32 students in the middle school and 84 students in the high school, and 2 food handlers, one from middle school and the other from high school, developed gastrointestinal illness symptoms including diarrhea. Following lab investigation identified 29 ETEC serotype O27:H7 strains, 27 from 116 students and 2 from 19 food handlers. Pattern of pulsed-field gel electrophoresis analysis of ETEC isolates suggested that ETEC serotype O27:H7 caused the diarrheal outbreak in June 2015 in Seoul, Korea was a specific clone. In addition, these ETEC serotype O27:H7 isolates were highly resistance to the several antibiotics. The results from the present study provide the evidence that ETEC serotype O27:H7 can be an important cause of domestic foodborne outbreak in Korea.
Subject(s)
Humans , Anti-Bacterial Agents , Clone Cells , Diarrhea , Electrophoresis, Gel, Pulsed-Field , Enterotoxigenic Escherichia coli , Escherichia coli , Gastrointestinal Diseases , Korea , Seoul , SerogroupABSTRACT
Of total 1,438 specimens of patients with diarrhea in Seoul, 2011, 217 samples (15%) were found pathogenic Escherichia coli that included 192 strains (89%) of enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). The highest isolation rate for ETEC and EAEC was found in August and September. Sixty two pathogenic E. coli strains (34 ETEC and 28 EAEC strains) were selected from 175 strains (94 ETEC and 81 EAEC strains) isolated in August and September. Of 94 strains characterized for ETEC phenotype, 76 (81%) expressed heat-stable toxin (ST) only. Antimicrobial susceptibility test was carried out by using sixteen types of antibiotics. A high level of antimicrobial resistance to tetracycline (57%), ampicillin and ticarcillin (54%) was observed among EAEC isolates while the highest resistance rate of ETEC was found for nalidixic acid (47%), followed by tetracycline (32%). As to the antimicrobial susceptibility test, EAEC showed the complicated multi-drug resistant patterns in which the resistance was higher than ETEC. Pulsed-field gel electrophoresis (PFGE) was carried out to examine the genetic relatedness among ETEC and EAEC isolates. Except for 11 strains, 51 strains were divided by eight pulsotypes. In PFGE analysis, isolates from foodborne disease outbreaks in August and September 2011 showed close relation.
Subject(s)
Humans , Ampicillin , Anti-Bacterial Agents , Diarrhea , Disease Outbreaks , Electrophoresis, Gel, Pulsed-Field , Enterotoxigenic Escherichia coli , Escherichia coli , Foodborne Diseases , Nalidixic Acid , Phenotype , Tetracycline , TicarcillinABSTRACT
The current study evaluated the presence of virulence factors by a multiplex PCR technique and then phylogenetically classified the studied strains into groups A, B1, B2 and D, according to Clermont et al. (2000), in 152 intestinal and extraintestinal swine isolates of Escherichia coli. Seventy seven isolates tested were positive for virulence factors. Phylogenetic characterization placed 21 samples into group A, 65 into B1, 19 into B2 and 47 into D. Fourteen urine samples were classified as uropathogenic E. coli (UPEC), nine were both UPEC and enterotoxigenic E. coli (ETEC) and four were ETEC only. The most common phylogenetic classifications were B1 and D groups. Of the analyzed fecal samples, 25 were classified as ETEC. Phylogenetically, the group of higher occurrence was B1, followed by B2, A and D. For the small intestine samples, 20 were classified as ETEC. Phylogenetic analysis found groups B1 and A to be the most commons in these samples. Six isolated tissue samples were classified as ETEC and most of them were designated as group D by phylogenetic classification. The phylogenetic analysis could be employed in veterinary laboratories in the E. coli isolates screening, including the possibility of vaccine strain selection and epidemiological searches.
O presente estudo teve por objetivo avaliar a presença de diferentes fatores de virulência em 152 isolados de Escherichia coli intestinais e extra-intestinais provenientes de suínos pela técnica de PCR multiplex e classificá-los nos grupos filogenéticos A, B1, B2 e D, de acordo com Clermont et al. (2000). Setenta e sete isolados foram positivos para pelo menos um fator de virulência. Através da caracterização filogenética, 21 isolados foram caracterizados como pertencentes ao grupo A, 65 ao grupo B1, 19 ao grupo B2 e 47 isolados ao grupo D. Quatorze isolados de urina foram caracterizados como E. coli uropatogênica (UPEC); nove apresentaram fatores de UPEC e E. coli enterotoxigênica (ETEC) simultaneamente e quatro foram classificados como ETEC. Na classificação filogenética, os isolados provenientes de amostras de urina classificaram-se principalmente nos grupos D e B1. Das amostras de fezes analisadas, 25 demonstraram fatores de virulência característicos do patotipo ETEC. Filogeneticamente, o grupo de maior ocorrência foi o B1 seguido de B2, A e D. Em relação às cepas isoladas de intestino delgado, 20 foram caracterizadas como ETEC. Pela filogenia, 23 isolados classificaram-se nos grupos A ou B1. Seis isolados de tecidos foram qualificados como ETEC e a maioria deles foram designados como pertencentes ao grupo D, pela classificação filogenética. A análise filogenética pode ser empregada em laboratórios de diagnóstico veterinário como um screening para isolados de E. coli, incluindo a possibilidade de seleção de cepas vacinais e levantamentos epidemiológicos.
Subject(s)
Animals , Enterotoxigenic Escherichia coli/virology , Uropathogenic Escherichia coli/virology , Escherichia coli/isolation & purification , Polymerase Chain Reaction/veterinary , Swine/microbiology , Feces/microbiology , Intestines/microbiology , Urine/microbiologyABSTRACT
Germanium biotite, a natural mineral, has been used as a feed supplement to reinforce innate immune ability. The aim of the present study was to evaluate the effects of germanium biotite on the adsorptive and inhibition of growth abilities against Escherichia (E.) coli and Salmonella spp. in vitro. Two strains of enterotoxigenic E. coli and four strains of two Salmonella serotypes (Salmonella Derby and Salmonella Typhimurium), major bacterial diarrheal pathogens, were used for this experiment. The absorptive ability of germanium biotite against most Salmonella used in present experiment was observed weakly. The germanium biotite, however, showed significant effect of bacterial growth inhibition in most experiment bacteria. These results suggest that the use of the germanium biotite as feed supplement could alleviate diarrhea following inhibition of bacteria growth. It is also presumed that antibiotics usage for farm animals, considered as causes of antibiotic residue in meat and emerging antibiotic resistance, could be reduced through the use of germanium biotite as a feed supplement, in place of antibiotics used for the prevention of diarrhea.
Subject(s)
Aluminum Silicates , Animals, Domestic , Anti-Bacterial Agents , Bacteria , Diarrhea , Drug Resistance, Microbial , Enterotoxigenic Escherichia coli , Escherichia , Ferrous Compounds , Germanium , Hypogonadism , Meat , Mitochondrial Diseases , Ophthalmoplegia , SalmonellaABSTRACT
The study evaluated drinking water from localities in and around Chandigarh for fecal coliforms, V.cholerae and Enterotoxigenic E.coli and correlate with occurrence of acute gastroenteritis occurring from the same region. Drinking water sample were collected from various sources from the defined area. Samples were tested for fecal coliforms and E.coli count by multiple tube method and pathogens by membrane filtration technique. E. coli were screened for heat labile toxin (LT) by the reverse passive agglutination method and heat stable toxin (ST) by ELISA. Stool samples from cases of acute gastroenteritis from the same region and time were collected and processed for V. cholerae, Enterotoxigenic E coli (ETEC) and others like Salmonella, Shigella and Aeromonas spp. Of 364 water samples examined, 116 (31.8%) samples were contaminated with fecal coliforms (58.5% rural, 33.4% semi-urban and 11.1% from urban areas). E. coli were grown from 58 samples. Ninety-two isolates of E. coli were tested for enterotoxins of which 8 and 24 were positive for LT and ST respectively. V. cholerae were isolated from 2 samples during the outbreak investigation. Stored water samples showed a significantly higher level of contamination and most of Enterotoxigenic E. coli were isolated from stored water samples. A total of 780 acute gastroenteritis cases occurred; 445 from semiurban, 265 rural and 70 from urban areas. Out of 189 stool samples submitted, ETEC were the commonest (30%) followed by V. cholerae (19%), Shigellae (8.4%), Salmonellae (2.1%) and Aeromonas (2.6%). ST-ETEC (40/57) were commoner than LT- ETEC(17/57). In the present study, high levels of contamination of drinking water supplies (32.1%) correlated well with cases of acute gastroenteritis. Majority of cases of acute gastroenteritis occurred in the semi-urban area corresponding with high level of contamination (33.4%). The highest level of water contamination was seen in rural areas (58.5%) but the number of acute gastroenteritis cases were lesser (33.9%) as ponds were infrequently used for drinking purpose. Safer household water storage and treatment is recommended to prevent acute gastroenteritis, together with point-of-use water quality monitoring.
ABSTRACT
The stool samples from 245 patients with diarrhea were tested for heat labile toxin (LT) and heat stable toxins (ST) by passive latex agglutination and enzyme immunoassay methods respectively. Twelve (4.9 percent) enterotoxigenic E. Coli ETEC strains were isolated. Five strains (2 percent) expressed ST, and 7 (2.8 percent) expressed LT.
Subject(s)
Humans , Infant, Newborn , Child, Preschool , Child , Clinical Enzyme Tests , Cross-Sectional Studies , Diarrhea, Infantile , Escherichia coli Infections , Enterotoxigenic Escherichia coli/enzymology , Enterotoxigenic Escherichia coli/isolation & purification , Bacterial Toxins/analysis , Bacterial Toxins/isolation & purification , Diagnostic Techniques and Procedures , Immunoassay , Methods , MethodsABSTRACT
This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.
Subject(s)
Animals , Cattle , Cattle Diseases/epidemiology , DNA, Bacterial/chemistry , Diarrhea/epidemiology , Escherichia coli/genetics , Escherichia coli Infections/epidemiology , Feces/microbiology , Fimbriae, Bacterial/genetics , Polymerase Chain Reaction/veterinary , Polymorphism, Restriction Fragment Length , Vietnam/epidemiology , Virulence Factors/geneticsABSTRACT
La diarrea del viajero (DV) afecta a 34 millones de personas que viajan a países en desarrollo todos los años. El destino representa el factor de riesgo más importante para el desarrollo de DV. Por mucho, los agentes etiológicos más frecuentes son bacterias patógenas (Escherichia coli enterotoxigénica, Escherichia coli enteroagregativa, Campylobacter, Salmonella). La reducción en la tasa de diarrea sería posible al evitar el consumo de alimentos y bebestibles contaminados. Una estrategia preventiva más eficaz consiste en administrar antibióticos todos los días durante viajes a áreas en que el riesgo de DV es alto. Rifaximina, antibiótico no absorbible recientemente aprobado, puede ser usado para el tratamiento de la DV en regiones donde la E. coli no invasora es el patógeno predominante. En áreas donde un organismo invasivo como el Campylobacter y Shigella son comunes, las fluoroquinolonas sigue siendo el medicamento escogido. La azitromicina es recomendada en áreas con Campylobacter resistente a las quinolonas y para el tratamiento de niños y mujeres embarazadas.
Travelers diarrhea (TD) affects 34 millions of people who travel to developing countries each year. Destination represents the single most important risk factor for developing TD. By far, the most frequent etiologic agents are bacterial pathogens (enterotoxigenic Escherichia coli, enteroaggregative E. coli, Campylobacter, Salmonella). Reduction in the rate of diarrhea maybe possible by avoiding contaminated foods and beverages. A more effective preventive strategy is daily administration of antibiotics during trips to areas where the risk of TD is high. Rifaximine, a recently approved non-absorbable antibiotic, can be used for the treatment of TD in regions where non invasive E. coli is the predominant pathogen. In areas where invasive organism such as Campylobacter and Shigella are common, fluoroquinolones remain the drug of choice. Azythromycin is recommended in areas with quinolone-resistant Campylobacter and for treatment of children and pregnant women.
Subject(s)
Humans , Diarrhea/epidemiology , Diarrhea/microbiology , Diarrhea/drug therapy , Travel , Anti-Bacterial Agents/administration & dosage , Gram-Negative Bacteria/pathogenicity , Diarrhea/prevention & control , Eukaryota/pathogenicity , Age Factors , Antibiotic ProphylaxisABSTRACT
Objective To investigate the fermentation conditions for the heat-labile enterotoxin B subunit (LTB) of genetic recombinant E.coli. Methods The effects of different kinds of media, the range of pH, the induction time, the glucose concentration, and the fed-batch on LTB level in 10-liter fermenter under the condition of cascade controlling dissolved oxygen content were analyzed. Results Under the established conditions, the cell output per liter was 40.5g, and the expression level was 30.6%. Conclusion The results indicate that the stable fermentation technology with high efficiency has been established.