Surveillance for this emerging disease should be expanded to the outpatient setting.

These findings indicate that transmission is determined by host infectivity and the number of contacts, whereas super-spreading events were determined by the number of contacts and hospital visits. These relationships highlight the importance of rapidly enforcing infection control measures to prevent outbreaks.

In the present study, carotenoids, anthocyanins, and phenolic acids of cauliflowers ( Brassica oleracea L. ssp. botrytis) with various colored florets (white, yellow, green, and purple) were characterized to determine their phytochemical diversity. Additionally, 48 metabolites comprising amino acids, organic acids, sugars, and sugar alcohols were identified using gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). Carotenoid content was considerably higher in green cauliflower; anthocyanins were detected only in purple cauliflower. Phenolic acids were higher in both green and purple cauliflower. Results of partial least-squares discriminant, Pearson correlation, and hierarchical clustering analyses showed that green cauliflower is distinct on the basis of the high levels of amino acids and clusters derived from common or closely related biochemical pathways. These results suggest that GC-TOFMS-based metabolite profiling, combined with chemometrics, is a useful tool for determining phenotypic variation and identifying metabolic networks connecting primary and secondary metabolism.

Abstract.A total of 720 Escherichia coli strains isolated from diarrheic piglets on 756 swine farms were screened for the presence of the enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1) gene by polymerase chain reaction (PCR). Escherichia coli strains that carried EAST1 genes were also tested by PCR for the presence of 4 fimbriae (F4, F5, F6, F41), 2 heat-stable enterotoxins (STa and STb), and 1 heat-labile enterotoxin (LT) gene. One hundred sixty-four (22.7%) of the 720 E. coli isolates carried genes for EAST1. Of these 164 isolates, 62 (37.8%) carried EAST1 genes only, 11 (6.7%) carried genes for at least 1 of the fimbrial adhesins, 51 (31.1%) carried genes for at least 1 of the enterotoxins, and 40 (23.8%) carried genes for at least 1 of the fimbrial adhesins and enterotoxins. Forty-six percent of strains that carried EAST1 genes carried STa genes, and 16% of strains that carried EAST1 genes carried F4. The isolation rate of enterotoxigenic E. coli strains carrying genes for EAST1 gene was 63%. The 6 major genotypes observed in this study (in decreasing order) were EAST1ϩ, EAST1ϩSTaϩ, EAST1ϩSTaϩSTbϩ, EAST1ϩSTaϩF5ϩ, EAST1ϩSTaϩF4ϩ, and EAST1ϩSTbϩF4ϩ. EAST1 is widely prevalent among diarrheagenic strains of E. coli and may represent an important virulence determinant in the pathogenesis of enteric colibacillosis of preweaned pigs.Escherichia coli is a major cause of diarrhea in human beings and animals. The 4 major groups are enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterohemorrhagic E. coli (EHEC). 5 Recently, evidence has accumulated to implicate a fifth distinct diarrheagenic category, enteroaggregative E. coli (EAggEC). The term enteroaggregative is derived from the pattern of adherence of bacteria to HEp-2 cells in culture. 6 EAggEC strains are a major cause of persistent diarrhea in children in the developing world. The aggregative adherence phenotype is associated with a bundle-forming pilus referred to as AAF/1. The genes for AAF/1 and a heat-stable enterotoxin 1 (EAST1) are carried on a 60-MD plasmid. EAST1 is genetically and immunologically distinct from heat-stable enterotoxin a (STa) produced by ETEC strains. 14,15 In addition to EAggEC, the EAST1 gene is also carried by human, porcine, and bovine ETEC strains. 1,10,15 The EAST1 gene sequence of F4ϩ ETEC strains is slightly different from that of human-colonizing ETEC strains. [14][15][16] The gene encoding EAST1 is highly prevalent among other groups of diarrheagenic E. coli isolated from humans, e.g., EHEC, ETEC, and EAggEC. 10 Although enteric colibacillosis is common in piglets, little is known concerning the prevalence of EAST1-positive E. coli and, thus, its potential significance in isolates from this species. The purpose of this study was to investigate the prevalence of the EAST1 gene in E. coli isolated from diarrheic piglets and to determine its relationship with other fimbrial (F4, F5, F6, and F41) and enterotoxin (STa, STb, and LT) genes by using polymerase chain reac...

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Polymerase chain reaction for 4 fimbriae (F4, F5, F6, F41), 2 heat-stable enterotoxins (STa, STb), and 1 heat-labile enterotoxin (LT) were performed on 400 Escherichia coli isolates to determine their genotype prevalence among enterotoxigenic E. coli isolates from preweaned pigs with diarrhea in the Republic of Korea. A total of 200 of the 400 E. coli isolates were also selected for characterization of the O serogroup. Of these 200 isolates, serogroup could be determined in 139 (69.5%) but not in 61 isolates (30.5%). Isolates of serogroup O101 were the most common, followed in descending order by 08, 020, 0162, 0141, and 0149. Ninety-seven (24.3%) of the 400 E. coli isolates carried genes for at least 1 of the entertoxins or fimbrial adhesins. Of these 97 isolates, 27 carried genes for at least 1 of the fimbrial adhesins and entertoxins. Sixty-six percent of the isolates that carried fimbrial adhesin genes carried genes for at least 1 of the enterotoxins, and 71% of the isolates that carried enterotoxin genes carried genes for at least 1 of the fimbrial adhesins. Genes for the F6 fimbriae were detected in 6% of the E. coli isolates, and F4+, F41+, and F5+ genes were detected in 4.3%, 3.3%, and 2% of the isolates, respectively. Genes for STa, STb, and LT were detected in 10%, 8.5%, and 4.3% of the isolates, respectively. The 6 major genotypes observed in this study (in decreasing order) were F6+, STb+, F41+, STa+STb+, F6+STa+, and STa+.

A PCR was used to determine the genotypic prevalence of five fimbrial adhesins (F4, F5, F6, F41 and F18), two heat-stable enterotoxins (STa and STb), the heat-labile enterotoxin (LT), and the shiga toxin 2e (Stx2e) in 230 isolates of Escherichia coli from postweaning pigs with diarrhoea or oedema disease. Ninety-four (40.9 per cent) of the isolates carried genes for at least one of the fimbrial adhesins or toxins. Genes for the F18 fimbrial adhesin were detected in 18.3 per cent, and genes for F4, F6, F5 and F41 were detected in 10.0 per cent, 4.3 per cent, 1.7 per cent and 0.8 per cent of the isolates, respectively. Genes for STa, STb and LT were detected in 25.7 per cent, 15.2 per cent and 8.7 per cent of the isolates, respectively. Genes for Stx2e were detected in 36 (15.6 per cent) of the isolates, and among them 24 also contained the gene for F18ab and four also contained the gene for F18ac.

ABSTRACT. The in vitro susceptibilities of 76 isolates of Actinobacillus pleuropneumoniae collected from pigs with pleuropneumonia were tested with 12 commonly used antimicrobial drugs by an agar dilution minimal inhibitory concentration procedure according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines. Field isolates had low MICs for ceftiofur, danofloxacin and penicillin. No correlation of antimicrobial resistance was related to serotype.KEY WORDS: Actinobacillus pleuropneumoniae, antimicrobial susceptibility, NCCLS, swine.J. Vet. Med. Sci. 63(3): 341-342, 2001 Actinobacillus pleuropneumoniae is the causative agent of pleuropneumonia which is one of the most important respiratory diseases in pigs worldwide. To date, at least twelve A. pleuropneumoniae serotypes (1 to 12) have been described with serotypes 1 and 5 being further subdivided into subtypes A and B [3,7]. Current bacterins provide only serotype specific protection. Differences in antimicrobial susceptibility of A. pleuropneumoniae isolates from country to country were detected for antimicrobial agents when comparing minimal inhibitory concentration (MIC) data from one country with those from another [1, 2, 5, 10, 11]. For pleuropneumonia treatment to be effective, it is important to know the antimicrobial susceptibility of A. pleuropneumoniae isolates that are isolated in each country. The objective of this study was to determine the antimicrobial susceptibility of A. pleuropneumoniae isolated from pigs in Korea using new standardized procedures for the antimicrobial susceptibility test for animal pathogens issued by the National Committee for Clinical Laboratory Standards (NCCLS) [6].Between 1995 and 1998, 76 isolates of A. pleuropneumoniae were isolated from 115 growing and finishing pigs with pleuropneumonia submitted from across Korea to the Department of Veterinary Pathology, Seoul National University. All pigs were submitted alive, and immediately upon receipt they were euthanatized for necropsy. The lung specimens were collected immediately for bacteriological culture on 5% sheep blood agar.The identification of isolates as A. pleuropneumoniae was based on Gram-staining, positive hemolysis on 5% sheep blood agar, a positive Christie-Atkins-MunchPetersen (CAMP) reaction, a requirement and detection of nicotinamide adenine dinucleotide, urease production, and xylose-and mannose-fermentation. The CAMP reaction was determined on 5% sheep blood agar, with a beta-hemolysis-producing Staphylococcus intermedius strain. Five isolates of A. pleuropneumoniae were isolated in 1995; 15 were isolated in 1996; 26 were isolated in 1997; and 30 were isolated in 1998. The serotypes of the 76 isolates of A. pleuropneumoniae tested in this study have been published: 46 were serotype 2, 20 were serotype 5, and 10 were serotype 6 [4].The following antimicrobial agents and combinations of antimicrobial agents were tested: ampicillin, amoxicillin, danofloxacin, trimethoprim-sulfamethoxazole (19:1), tiamulin, tylosin, tetracycline, pen...