This study was conducted to investigate the presence of Escherichia (E.) coli O157 and E. coli O157:H7 and stx1 and stx2 genes on cattle carcasses and in rectal samples collected from Samsun Province of Turkey. A total of 200 samples collected from cattle carcasses and the rectal contents of 100 slaughtered cattle from two commercial abattoirs were tested using the immunomagnetic separation technique and multiplex PCR methods. E. coli O157 and E. coli O157:H7 were detected in 52 of the 200 samples (26%) tested. Of the positive samples, 49 were E. coli O157 and three were E. coli O157:H7. The E. coli O157 strain was isolated from 24 carcasses and 25 rectal samples, while E. coli O157:H7 was isolated from two carcasses and one rectal sample. Of the 49 samples positive for E. coli O157, 32 were from the rectal and carcass samples of the same animal, while two E. coli O157:H7 isolates were obtained from rectal swabs and carcasses of the same animal. The stx1 and stx2 genes were both detected in 35 E. coli O157 isolates and one E. coli O157:H7 isolate, but the stx2 gene was only detected alone in two E. coli O157 isolates. Overall, 16 carcasses tested positive for E. coli O157 and one carcass tested positive for E. coli O157:H7 based on both carcass and rectal samples. Overall, the results of this study indicate that cattle carcasses pose a potential risk to human health due to contamination by E. coli O157 and E. coli O157:H7 in the feces.
Abattoirs ; Animals ; Cattle ; Escherichia coli O157/*genetics/isolation & purification ; *Immunomagnetic Separation ; Meat/microbiology ; *Polymerase Chain Reaction ; Rectum/microbiology ; Shiga Toxin 1/*genetics ; Shiga Toxin 2/*genetics ; Turkey

China ; epidemiology ; Escherichia coli Infections ; epidemiology ; microbiology ; Escherichia coli O157 ; classification ; isolation & purification ; metabolism ; Humans ; Shiga Toxin 1 ; biosynthesis ; isolation & purification ; Shiga Toxin 2 ; biosynthesis ; isolation & purification ; Sorbitol

OBJECTIVETo establish a triplex TaqMan real-time PCR system containing internal amplification control (IAC) to detect cholera toxin gene ctxA and enterotoxigenic Escherichia coli (ETEC)heat-labile enterotoxin gene elt.

METHODSPrimers and probes were designed based on the sequences of ctxA, elt and IAC. Both sensitivity and specificity were analyzed and interactions between different reactions were evaluated.

RESULTSThis system showed that the sensitivity of ctxA was 94 copies/reaction while the elt 79 copies/reaction and the amplification efficiency were 94.7% and 98.1%, respectively. Under the ratio of copy numbers on gene ctxA to elt as between 1 : 1-1 : 10, when both targets were detected, with impact was less on each other. However, when the amount of elt or ctxA was 100 times of IAC, the amplification of IAC was significantly inhibited.

CONCLUSIONThis system showed both satisfactory sensitivity and specificity, thus could be used to detect pathogenic bacteria in diarrhea stools. The detection of IAC could prompt the presence of PCR inhibitors in samples being tested.

No abstract available.
Aeromonas* ; Enterotoxins*

Cholera enterotoxin (CT) is a major virulence determinant of Vibrio cholerae 01. CI' is known to be the major virulence factor of Vibrio cholerae 01 and in accordance with the recent report showing which V. cholerae non-01 has ctx gene, we performed the molecular genetic study for the detection of ctx gene related to the production of CT at the subject Vibrio spp. except for V. cholerae non-01 and V. cholerae non-01 stock cultured in the laboratory of microbiology, College of Medicine, Pusan National University and the Vibrio spp. isolated from the marine products of Pusan General Fish Market and the sea water, and then its results are as follows: 1. PCR for the detection of ctx gene at the subject of V. cholerae 01:61H-151 having the ctx gene of which the denaturation is 1 rninute at 95'C, annealing to 1min, 30 sec at 60'C, the extension to be 1min. 30 sec at 72'C and 30 or 40 cycles. ctx gene was detected from 4 strains of V. cholera non-01 derived from the environment isolates. 2. Adjusting the quantity of chromosomal DNA used as template DNA to be from 0.1 pg to 1 ng, in order to know the PCR conditions for the effective search of ctx gene, and the detection limit of the system was 10 pg of chromosomal DNA. 3. The broth culture was used for template DNA, ctx gene of 302 bp was detected from 4 V. cholerae non-01, as in the case of chromosomal DNA, and the cell number was possible to be detected to 3 * 10.4. We attempted the confirmation of ctx gene through Southern blot hybridization, labeling with P and then it was confirmed only from 4 V. cholerae non-01 as like PCR results. 5. As the result of the sensitivity of PCR and Southern blot hybridization, it was shown to be possible which 10 pg was detected in case of chromosomal DNA and in case of cultured broth, the cell number was detected until 10 at PCR and Southern blot hybridization, and thus it was examed which its sensitivity was same.
Blotting, Southern ; Busan ; Cell Count ; Cholera Toxin* ; Cholera* ; DNA* ; Enterotoxins ; Limit of Detection ; Molecular Biology ; Operon* ; Polymerase Chain Reaction* ; Seawater ; Vibrio cholerae* ; Vibrio* ; Virulence

Cholera is an acute secretory form of diarrhea caused by a potent enterotoxin (cholera toxin) after ingestion of toxigenic Vibrio cholerae of the O1 or O139 serogroups. Although cholera is very common in Africa and Asia as a whole, the incidence of cholera has been very low in recent years in Korea. Dehydration and electrolyte abnormalities due to massive watery diarrhea can lead to death, and the mortality rates in untreated patients with severe cholera can exceed 70%. Effective rehydration therapy is the cornerstone of the management of patients with cholera and can reduce the mortality rate to less than 0.2%. Antibiotics reduce the volume and duration of diarrhea, but are recommended for patients with severe disease because of the rapid emergence and spread of multidrug-resistant V. cholerae across the globe. Two oral cholera vaccines are available, and the World Health Organization recommends that these oral vaccines be considered in integrated prevention programs in endemic countries at risk for outbreaks.
Africa ; Anti-Bacterial Agents ; Asia ; Cholera Toxin ; Cholera Vaccines ; Cholera* ; Dehydration ; Diarrhea ; Disease Outbreaks ; Eating ; Enterotoxins ; Epidemiology* ; Fluid Therapy ; Humans ; Incidence ; Korea ; Mortality ; Serogroup ; Vaccines ; Vibrio cholerae ; World Health Organization

No abstract available.
Enterotoxigenic Escherichia coli* ; Enterotoxins*

No abstract available.
Enterotoxigenic Escherichia coli* ; Enterotoxins*

A multiplex loop-mediated isothermal amplification (mLAMP) assay was developed for simultaneous detection of the stx1 and stx2 genes and applied for detection of shiga toxin-producing Escherichia coli (STEC) in cattle farm samples. Two target genes were distinguished based on T m values of 85.03 +/- 0.54degrees C for stx1 and 87.47 +/- 0.35degrees C for stx2. The mLAMP assay was specific (100% inclusivity and exclusivity), sensitive (with a detection limit as low as 10 fg/microL), and quantifiable (R 2 = 0.9313). The efficacy and sensitivity were measured to evaluate applicability of the mLAMP assay to cattle farm samples. A total of 12 (12/253; 4.7%) and 17 (17/253; 6.7%) STEC O157, and 11 (11/236; 4.7%) non-O157 STEC strains were isolated from cattle farm samples by conventional selective culture, immunomagnetic separation, and PCR-based culture methods, respectively. The coinciding multiplex PCR and mLAMP results for the types of shiga toxin revealed the value of the mLAMP assay in terms of accuracy and rapidity for characterizing shiga toxin genes. Furthermore, the high detection rate of specific genes from enrichment broth samples indicates the potential utility of this assay as a screening method for detecting STEC in cattle farm samples.
Animals ; Cattle ; Cattle Diseases/epidemiology/microbiology ; Escherichia coli Infections/epidemiology/microbiology/*veterinary ; Feces/microbiology ; Multiplex Polymerase Chain Reaction/veterinary ; Nucleic Acid Amplification Techniques/*veterinary ; Shiga Toxin 1/*genetics/isolation & purification ; Shiga Toxin 2/*genetics/isolation & purification ; Shiga-Toxigenic Escherichia coli/*genetics/isolation & purification

A total of 156 Shiga-like toxin producing Escherichia coli (STEC) were isolated from fecal samples of Korean native (100/568, 18%) and Holstein dairy cattle (56/524, 11%) in Korea between September 2010 and July 2011. Fifty-two STEC isolates (33%) harbored both of shiga toxin1 (stx1) and shiga toxin2 (stx2) genes encoding enterohemolysin (EhxA) and autoagglutinating adhesion (Saa) were detected by PCR in 83 (53%) and 65 (42%) isolates, respectively. By serotyping, six STEC from native cattle and four STEC from dairy cattle were identified as O-serotypes (O26, O111, O104, and O157) that can cause human disease. Multilocus sequence typing and pulsed-field gel electrophoresis patterns highlighted the genetic diversity of the STEC strains and difference between strains collected during different years. Antimicrobial susceptibility tests showed that the multidrug resistance rate increased from 12% in 2010 to 42% in 2011. Differences between isolates collected in 2010 and 2011 may have resulted from seasonal variations or large-scale slaughtering in Korea performed to control a foot and mouth disease outbreak that occurred in early 2011. However, continuous epidemiologic studies will be needed to understand mechanisms. More public health efforts are required to minimize STEC infection transmitted via dairy products and the prevalence of these bacteria in dairy cattle.
Animals ; Anti-Bacterial Agents/pharmacology ; Cattle/microbiology ; Drug Resistance, Multiple, Bacterial ; Electrophoresis, Gel, Pulsed-Field/veterinary ; Escherichia coli Infections/epidemiology/microbiology/*veterinary ; Female ; Genes, Bacterial/genetics ; Latex Fixation Tests/veterinary ; Microbial Sensitivity Tests/veterinary ; Multilocus Sequence Typing/veterinary ; Prevalence ; Republic of Korea/epidemiology ; Shiga Toxin 1/genetics ; Shiga Toxin 2/genetics ; *Shiga-Toxigenic Escherichia coli/drug effects/genetics