Sequence type (ST) 33 of Shiga toxin-producing Escherichia coli (STEC) strain O91:H14 has been proposed as a potential domestic clone of STEC in Korea because of its high prevalence among human patients with mild diarrhea or asymptomatic carriers. Herein, the clonal diversity of 17 STEC O91:H14 isolates of ST33 during 2003 to 2014 was analyzed by pulsed-field gel electrophoresis, including 14 isolates from human patients and 3 from retail meats. Their virulence characteristics, acid resistance, and antimicrobial susceptibility were also determined. Our results showed that all isolates were clustered mainly into three different pulsotypes and were likely low pathogenic without antimicrobial resistance.
Clone Cells ; Diarrhea ; Electrophoresis, Gel, Pulsed-Field ; Escherichia coli ; Humans ; Korea ; Meat ; Molecular Epidemiology ; Prevalence ; Shiga Toxin ; Shiga-Toxigenic Escherichia coli ; Virulence

To diagnose colibacillosis, detection of O-serogroups and virulence genes has been recommended worldwide. The prevalence of virulence factors can fluctuate over time. The objectives of this study were to determine the prevalence of O-serogroups, virulence genes, and F18 subtypes among pathogenic Escherichia coli isolated from weaned piglets with diarrhea in Korea. Between 2008 and 2016, 362 E. coli were isolated from weaned piglets with diarrhea. Hemolysis was determined in blood agar, and O-serogroups were identified using the slide agglutination technique. The genes for the toxins and fimbriae were amplified by polymerase chain reaction (PCR). Real-time PCR was conducted to discriminate between F18 subtypes. Although the most prevalent serogroup was O149 (11.3%) in the last 9 years, O139 (19.1%) became the most prevalent in recent years (2015–2016). The most predominant pathotype was enterotoxigenic E. coli (61.3%). The frequencies of Shiga-like toxin-producing E. coli (STEC) (23.4%), O139 (19.1%), Stx2e (35.1%), and F18ab (48.7%) increased over the most recent years. Although enterotoxigenic E. coli was the most predominant pathotype, the frequencies of O139, Stx2e, STEC, and F18ab have increased in recent years. These results demonstrate that there have been temporal changes in the predominant O-serogroups and virulence genes over the last decade in Korea. These findings can be practicable for use in epidemiology and control measures for enteric colibacillosis in Korean piggeries.
Agar ; Agglutination ; Diarrhea ; Enterotoxigenic Escherichia coli ; Epidemiology ; Escherichia coli ; Escherichia ; Hemolysis ; Korea ; Polymerase Chain Reaction ; Prevalence ; Real-Time Polymerase Chain Reaction ; Serogroup ; Shiga-Toxigenic Escherichia coli ; Virulence Factors ; Virulence

Atypical hemolytic uremic syndrome (aHUS), a rare form of thrombotic microangiopathy, is distinguished from the typical form by the absence of a preceding verotoxin-producing Escherichia coli infection. Notably, aHUS occurs in association with genetic or acquired disorders causing dysregulation of the alternative complement pathway. Patients with aHUS may show the presence of anti-complement factor H (CFH) autoantibodies. This acquired form of aHUS (anti-CFH-aHUS) primarily affects children aged 9–13 years. We report a case of a 13-year-old Lao girl with clinical features of aHUS (most likely anti-CFH-aHUS). The initial presentation of the patient met the classical clinical triad of thrombotic microangiopathy (microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury) without preceding diarrheal illness. Low serum levels of complement 3 and normal levels of complement 4 indicated abnormal activation of the alternative complement pathway. Plasma infusion and high-dose corticosteroid therapy resulted in improvement of the renal function and hematological profile, although the patient subsequently died of infectious complications. This is the first case report that describes aHUS (possibly anti-CFH-aHUS) in Laos.
Adolescent ; Anemia, Hemolytic ; Atypical Hemolytic Uremic Syndrome ; Autoantibodies ; Child ; Complement C3 ; Complement C4 ; Complement Factor H ; Complement Pathway, Alternative ; Female ; Humans ; Immunosuppression ; Kidney ; Laos ; Plasma ; Shiga-Toxigenic Escherichia coli ; Thrombocytopenia ; Thrombotic Microangiopathies

BACKGROUND: We attempted to determine the characteristics of diarrheal pathogens according to species, seasonal variations, and patient age using multiplex PCR for the epidemiologic study of diarrheal disease in Jeju Island. METHODS: From March 2015 to Feb 2017, stool specimens were collected from 537 diarrheal patients older than 16 years. Multiplex PCR was used to identify pathogens and found Group A Rotavirus, enteric Adenovirus, Norovirus GI/GII, Astrovirus, Salmonella spp., Shigella spp., Vibrio spp., Campylobacter spp., Clostridium difficile toxin B (CDB), Clostridium perfringens, Yersinia enterocolitica, Aeromonas spp., Escherichia coli O157:H7, and verocytotoxin-producing E. coli (VTEC). RESULTS: Pathogens were isolated from 221 of 537 samples (41.2%); 9.3% were positive only for viral pathogens; 30.2%, only for bacterial pathogens; and 1.7%, for both viral and bacterial pathogens. Bacteria were more prevalent in spring, summer, and autumn, but viral pathogens were more prevalent in winter. Overall prevalence were Campylobacter spp. (26.7%), Clostridium perfringens (23.9%); Norovirus GII (11.4%), CDB (8.2%), Aeromonas spp. (6.3%), Group A Rotavirus (5.1%), Salmonella spp. (3.9%), Astrovirus (3.9%), Norovirus GI (3.1%), Vibrio spp (2.7%), enteric Adenovirus (1.6%), Shigella spp. (1.2%), VTEC (1.2%), and Yersinia enterocolitica (0.4%). Group A Rotavirus and Norovirus GII were more prevalent in winter and early spring. Campylobacter spp., CDB, and C. perfringens were detected frequently, without seasonal variation. CONCLUSION: Bacterial pathogens are more prevalent than viruses in acute diarrhea in adults living in Jeju Island, especially in spring, summer, and autumn. Viral pathogens are prevalent in winter. Campylobacter spp., CDB, and Clostridium perfringens are the major pathogens occurring without seasonal variations. These data will be helpful in identifying diarrheal pathogens and for treatments and prevention strategies.
Adenoviridae ; Adult* ; Aeromonas ; Bacteria ; Campylobacter ; Clostridium difficile ; Clostridium perfringens ; Diarrhea ; Epidemiologic Studies* ; Epidemiology ; Escherichia coli ; Humans ; Multiplex Polymerase Chain Reaction* ; Norovirus ; Prevalence ; Rotavirus ; Salmonella ; Seasons ; Shiga-Toxigenic Escherichia coli ; Shigella ; Vibrio ; Yersinia enterocolitica

Herein, we report the pathogenic and phylogenetic characteristics of seven Shiga toxin (Stx)-producing Escherichia coli (STEC) isolates from 434 retail meats collected in Korea during 2006 to 2012. The experimental analyses revealed that all isolates (i) were identified as non-O157 STEC, including O91:H14 (3 isolates), O121:H10 (2 isolates), O91:H21 (1 isolate), and O18:H20 (1 isolate), (ii) carried diverse Stx subtype genes (stx₁, stx(2c), stx(2e), or stx₁ + stx(2b)) whose expression levels varied strain by strain, and (iii) lacked the locus of enterocyte effacement (LEE) pathogenicity island, a major virulence factor of STEC, but they possessed one or more alternative virulence genes encoding cytotoxins (Cdt and SubAB) and/or adhesins (Saa, Iha, and EcpA). Notably, a significant heterogeneity in glutamate-induced acid resistance was observed among the STEC isolates (p < 0.05). In addition, phylogenetic analyses demonstrated that all three STEC O91:H14 isolates were categorized into sequence type (ST) 33, of which two beef isolates were identical in their pulsotypes. Similar results were observed with two O121:H10 pork isolates (ST641; 88.2% similarity). Interestingly, 96.0% of the 100 human STEC isolates collected in Korea during 2003 to 2014 were serotyped as O91:H14, and the ST33 lineage was confirmed in approximately 72.2% (13/18 isolates) of human STEC O91:H14 isolates from diarrheal patients.
Cytotoxins ; Enterocytes ; Escherichia coli ; Genomic Islands ; Humans ; Korea ; Meat ; Population Characteristics ; Red Meat ; Shiga Toxin ; Shiga-Toxigenic Escherichia coli ; Virulence ; Virulence Factors

PURPOSE: This study clarified the bacterial pathogens currently causing acute infectious enterocolitis (AIE) in children and evaluated the clinical characteristics and ultrasonographic findings according to the different pathogens. METHODS: Medical records regarding age, sex, clinical symptoms, laboratory data, identified enteropathogens, ultrasonographic findings, treatment, and outcome of 34 patients who were diagnosed with AIE via stool examination using multiplex polymerase chain reaction (PCR) or culture, were retrospectively reviewed. RESULTS: Twenty-four patients (70.6%) were male. The mean age of the patients was 8.5±6.2 (range, 1.1–17.1) years. Six bacterial pathogens were isolated: Salmonella species (spp.) (32.4%), Campylobacter spp. (20.6%), verotoxin-producing Escherichia coli (14.7%), Staphylococcus aureus (11.8%), Clostridium difficile (8.8%), and Shigella spp. (2.9%). Abdominal pain occurred in all patients regardless of pathogen. The patients infected with Salmonella were older than those infected with verotoxin-producing E. coli (p<0.05). C-reactive protein levels were higher in patients with Salmonella and Campylobacter infections than in those with verotoxin-producing E. coli infection (p<0.05), the other clinical and laboratory data were indistinguishable between pathogens. Ultrasonography demonstrated diverse involvement of bowel segments according to pathogen. Wall thickening of both the ileum and the entire colon was the most common lesion site regardless of pathogen. CONCLUSION: Various bacterial agents cause AIE and the symptoms are diverse symptoms, however, all most children recovered spontaneously. Use of multiplex PCR on stool samples warrants improvement of its sensitivity for diagnosis of enteropathogenic bacteria. Ultrasonographic examination is useful for diagnosis of AIE; it can also detect the disease extent and severity.
Abdominal Pain ; Bacteria ; C-Reactive Protein ; Campylobacter ; Campylobacter Infections ; Child* ; Clostridium difficile ; Colon ; Diagnosis ; Enterocolitis* ; Humans ; Ileum ; Male ; Medical Records ; Multiplex Polymerase Chain Reaction ; Retrospective Studies ; Salmonella ; Shiga-Toxigenic Escherichia coli ; Shigella ; Staphylococcus aureus ; Ultrasonography

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0–4 years, less in adults < 40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P < 0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.
Adenoviridae ; Adult ; Bacteria ; Campylobacter ; Child ; Clostridium difficile ; Coinfection ; Cryptosporidium ; Developing Countries ; Diarrhea ; Entamoeba histolytica ; Enterotoxigenic Escherichia coli ; Giardia ; Giardia lamblia ; Humans ; Norovirus ; Prospective Studies ; Rotavirus ; Salmonella ; Saudi Arabia ; Shiga-Toxigenic Escherichia coli ; Shigella ; Vibrio cholerae ; Yersinia enterocolitica

Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowledge, this is the first report of S. Enteritidis in the culpeo fox (Lycalopex culpaeus), black-capped capuchin (Sapajus apella) and Peruvian pelican (Pelecanus thagus) and the first STEC report in Thomson's gazelle (Eudorcas thomsonii).
Animals ; Animals, Zoo* ; Chile* ; Feces ; Prevalence* ; Salmonella enterica* ; Salmonella* ; Serogroup ; Shiga-Toxigenic Escherichia coli*

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