Signatures of a jet cocoon in early spectra of a supernova associated with a γ-ray burst.

Long γ-ray bursts are associated with energetic, broad-lined, stripped-envelope supernovae1,2 and as such mark the death of massive stars. The scarcity of such events nearby and the brightness of the γ-ray burst afterglow, which dominates the emission in the first few days after the burst, have so far prevented the study of the very early evolution of supernovae associated with γ-ray bursts3. In hydrogen-stripped supernovae that are not associated with γ-ray bursts, an excess of high-velocity (roughly 30,000 kilometres per second) material has been interpreted as a signature of a choked jet, which did not emerge from the progenitor star and instead deposited all of its energy in a thermal cocoon4. Here we report multi-epoch spectroscopic observations of the supernova SN 2017iuk, which is associated with the γ-ray burst GRB 171205A. Our spectra display features at extremely high expansion velocities (around 115,000 kilometres per second) within the first day after the burst5,6. Using spectral synthesis models developed for SN 2017iuk, we show that these features are characterized by chemical abundances that differ from those observed in the ejecta of SN 2017iuk at later times. We further show that the high-velocity features originate from the mildly relativistic hot cocoon that is generated by an ultra-relativistic jet within the γ-ray burst expanding and decelerating into the medium that surrounds the progenitor star7,8. This cocoon rapidly becomes transparent9 and is outshone by the supernova emission, which starts to dominate the emission three days after the burst.

A surge of light at the birth of a supernova.

It is difficult to establish the properties of massive stars that explode as supernovae. The electromagnetic emission during the first minutes to hours after the emergence of the shock from the stellar surface conveys important information about the final evolution and structure of the exploding star. However, the unpredictable nature of supernova events hinders the detection of this brief initial phase. Here we report the serendipitous discovery of a newly born, normal type IIb supernova (SN 2016gkg), which reveals a rapid brightening at optical wavelengths of about 40 magnitudes per day. The very frequent sampling of the observations allowed us to study in detail the outermost structure of the progenitor of the supernova and the physics of the emergence of the shock. We develop hydrodynamical models of the explosion that naturally account for the complete evolution of the supernova over distinct phases regulated by different physical processes. This result suggests that it is appropriate to decouple the treatment of the shock propagation from the unknown mechanism that triggers the explosion.

Increased metabolite production by deletion of an HDA1-type histone deacetylase in the phytopathogenic fungi, Magnaporthe oryzae (Pyricularia oryzae) and Fusarium asiaticum.

Histone deacetylases (HDACs) play an important role in the regulation of chromatin structure and gene expression. We found that dark pigmentation of Magnaporthe oryzae (anamorph Pyricularia oryzae) ΔMohda1, a mutant strain in which an orthologue of the yeast HDA1 was disrupted by double cross-over homologous recombination, was significantly stimulated in liquid culture. Analysis of metabolites in a ΔMohda1 mutant culture revealed that the accumulation of shunt products of the 1,8-dihydroxynaphthalene melanin and ergosterol pathways were significantly enhanced compared to the wild-type strain. Northern blot analysis of the ΔMohda1 mutant revealed transcriptional activation of three melanin genes that are dispersed throughout the genome of M. oryzae. The effect of deletion of the yeast HDA1 orthologue was also observed in Fusarium asiaticum from the Fusarium graminearum species complex; the HDF2 deletion mutant produced increased levels of nivalenol-type trichothecenes. These results suggest that histone modification via HDA1-type HDAC regulates the production of natural products in filamentous fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: Natural products of fungi have significant impacts on human welfare, in both detrimental and beneficial ways. Although HDA1-type histone deacetylase is not essential for vegetative growth, deletion of the gene affects the expression of clustered secondary metabolite genes in some fungi. Here, we report that such phenomena are also observed in physically unlinked genes required for melanin biosynthesis in the rice blast fungus. In addition, production of Fusarium trichothecenes, previously reported to be unaffected by HDA1 deletion, was significantly upregulated in another Fusarium species. Thus, the HDA1-inactivation strategy may be regarded as a general approach for overproduction and/or discovery of fungal metabolites.

Pregnancies with factor V deficiency: a case report and review of the literature.

CASE REPORT: A 30-year-old Japanese nulliparous woman visited for pregnancy at 33 weeks with a massive ovarian tumor located in the pouch of Douglas. By preoperative screening, her prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged, and her FV activity was significantly decreased to 4.8%. After prophylactic FFP 20 ml/kg was administered and her FV factor was 19.3%, cesarean delivery was performed, and her perioperative course was uneventful. One year later, she underwent a dilatation and evacuation because of a missed abortion, although prophylactic FFP was not administered. During a third pregnancy, after prophylactic FFP 20 ml/kg was administered and FV activity increased to 21.1%, elective cesarean delivery was performed, and her postoperative course was uneventful. CONCLUSION: For surgical therapy or delivery, the goal of therapy is to maintain FV activity above 20%. It is particularly useful to administer prophylactic FFP.

A randomized phase III trial comparing S-1 versus UFT as adjuvant chemotherapy for stage II/III rectal cancer (JFMC35-C1: ACTS-RC).

BACKGROUNDS: Preventing distant recurrence and achieving local control are important challenges in rectal cancer treatment, and use of adjuvant chemotherapy has been studied. However, no phase III study comparing adjuvant chemotherapy regimens for rectal cancer has demonstrated superiority of a specific regimen. We therefore conducted a phase III study to evaluate the superiority of S-1 to tegafur-uracil (UFT), a standard adjuvant chemotherapy regimen for curatively resected stage II/III rectal cancer in Japan, in the adjuvant setting for rectal cancer. PATIENTS AND METHODS: The ACTS-RC trial was an open-label, randomized, phase III superiority trial conducted at 222 sites in Japan. Patients aged 20-80 with stage II/III rectal cancer undergoing curative surgery without preoperative therapy were randomly assigned to receive UFT (500-600 mg/day on days 1-5, followed by 2 days rest) or S-1 (80-120 mg/day on days 1-28, followed by 14 days rest) for 1 year. The primary end point was relapse-free survival (RFS), and the secondary end points were overall survival and adverse events. RESULTS: In total, 961 patients were enrolled from April 2006 to March 2009. The primary analysis was conducted in 480 assigned to receive UFT and 479 assigned to receive S-1. Five-year RFS was 61.7% [95% confidence interval (CI) 57.1% to 65.9%] for UFT and 66.4% (95% CI 61.9% to 70.5%) for S-1 [P = 0.0165, hazard ratio (HR): 0.77, 95% CI 0.63-0.96]. Five-year survival was 80.2% (95% CI 76.3% to 83.5%) for UFT and 82.0% (95% CI 78.3% to 85.2%) for S-1. The main grade 3 or higher adverse events were increased alanine aminotransferase and diarrhea (each 2.3%) in the UFT arm and anorexia, diarrhea (each 2.6%), and fatigue (2.1%) in the S-1 arm. CONCLUSION: One-year S-1 treatment is superior to UFT with respect to RFS and has therefore become a standard adjuvant chemotherapy regimen for stage II/III rectal cancer following curative resection.

A massive star origin for an unusual helium-rich supernova in an elliptical galaxy.

The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from all supernovae hitherto observed by its faint and rapidly fading light curve, prominent calcium lines in late-phase spectra and lack of any mark of recent star formation near the supernova location. These properties are claimed to be explained by a helium detonation in a thin surface layer of an accreting white dwarf. Here we report that the observed properties of SN 2005cz, which appeared in an elliptical galaxy, resemble those of SN 2005E. We argue that these properties are best explained by a core-collapse supernova at the low-mass end (8-12 solar masses) of the range of massive stars that explode. Such a low-mass progenitor lost its hydrogen-rich envelope through binary interaction, had very thin oxygen-rich and silicon-rich layers above the collapsing core, and accordingly ejected a very small amount of radioactive (56)Ni and oxygen. Although the host galaxy NGC 4589 is an elliptical, some studies have revealed evidence of recent star-formation activity, consistent with the core-collapse model.

An asymmetric explosion as the origin of spectral evolution diversity in type Ia supernovae.

Type Ia supernovae form an observationally uniform class of stellar explosions, in that more luminous objects have smaller decline-rates. This one-parameter behaviour allows type Ia supernovae to be calibrated as cosmological 'standard candles', and led to the discovery of an accelerating Universe. Recent investigations, however, have revealed that the true nature of type Ia supernovae is more complicated. Theoretically, it has been suggested that the initial thermonuclear sparks are ignited at an offset from the centre of the white-dwarf progenitor, possibly as a result of convection before the explosion. Observationally, the diversity seen in the spectral evolution of type Ia supernovae beyond the luminosity-decline-rate relation is an unresolved issue. Here we report that the spectral diversity is a consequence of random directions from which an asymmetric explosion is viewed. Our findings suggest that the spectral evolution diversity is no longer a concern when using type Ia supernovae as cosmological standard candles. Furthermore, this indicates that ignition at an offset from the centre is a generic feature of type Ia supernovae.

Levobupivacaine-dextran mixture for transversus abdominis plane block and rectus sheath block in patients undergoing laparoscopic colectomy: a randomised controlled trial.

We performed a randomised controlled double-blinded study of patients having laparoscopic colectomy with bilateral transversus abdominis plane block plus rectus sheath block, comparing a control group receiving 80 ml levobupivacaine 0.2% in saline with a dextran group receiving 80 ml levobupivacaine 0.2% in 8% low-molecular weight dextran. Twenty-seven patients were studied in each group. The mean (SD) maximum plasma concentration of levobupivacaine in the control group (1410 (322) ng.ml(-1) ) was higher than the dextran group (1141 (287) ng.ml(-1) ; p = 0.004), and was reached more quickly (50.6 (30.2) min vs 73.2 (24.6) min; p = 0.006). The area under the plasma concentration-time curve from 0 min to 240 min in the control group (229,124 (87,254) ng.min.ml(-1) ) was larger than in the dextran group (172,484 (50,502) ng.min.ml(-1) ; p = 0.007). The median (IQR [range]) of the summated numerical pain rating score at rest during the first postoperative 24 h in the control group (16 (9-20 [3-31]) was higher than in the dextran group (8 (2-11 [0-18]); p = 0.0001). In this study, adding dextran to levobupivacaine decreased the risk of levobupivacaine toxicity while providing better analgesia.

The long-term outcome of transvaginal anterior levatorplasty for intractable rectovaginal fistula.

AIM: Several procedures have been described for rectovaginal fistula with a wide range of success, but there is little information on the long-term outcome. The aim of the present study was to investigate the long-term outcome after transvaginal anterior levatorplasty (ALP) for intractable rectovaginal fistula. METHOD: Data of 16 consecutive patients undergoing transvaginal ALP with fistulectomy and closure of the rectum and vagina between 1998 and 2011 were prospectively recorded and retrospectively investigated to study the long-term outcome. RESULTS: Birth injury (n = 7), low anterior resection for rectal cancer (n = 3), pouch surgery for ulcerative colitis (n = 2) and a procedure for prolapse and haemorrhoids (n = 2) were the main causes of the fistula. Nine patients had a covering stoma before surgery. All patients underwent ALP, with a covering stoma in two patients. Infection occurred in one patient and wound rupture after surgery in another patient. These patients underwent reoperation by ALP. All fistulae had healed at a median follow-up of 84 (8-193) months after initial surgery or stoma closure. CONCLUSION: Transvaginal ALP is effective for the treatment of mid or low rectovaginal fistula. The results show that a graft is not necessary regardless of whether or not previous surgery has been performed.

Stockmanship competence and its relation to productivity and economic profitability: the context of backyard goat production in the Philippines.

A stockperson has a significant influence on the productivity and welfare of his animals depending on his stockmanship competence. In this study, stockmanship competence (SC) is defined as the capacity of the stockperson to ensure the welfare of his animals by providing his animals' needs. The study was conducted to evaluate the SC of backyard goat raisers and examine its relationship to goat productivity and economic profitability. There were 101 respondents for this study who have all undertaken farmer livestock school on integrated goat management (FLS-IGM). Interview was conducted in Region I, Philippines on September 3 to 30, 2012 and March 4 to 17, 2013. Data on SC, goat productivity and farmer's income were gathered. Questions regarding SC were formulated based on the Philippine Recommendations for Goat Production and from other scientific literature. Housing, feeding, breeding and health and husbandry management were the indicators used in computing stockmanship competence index score (SCIS). Pearson correlation using Statistical Package for Social Science (SPSS) was carried out to analyse the relationship between SCIS, productivity and income. Based from the results of the study, a majority of the respondents raised native and upgraded goats. The computed mean SCIS before and after undergoing FLS-IGM were 38.52% and 75.81% respectively, a percentage difference of 65.23%. Both index scores resulted in significant differences in productivity and income. The median mature weight and mortality rate of goats before FLS-IGM was 14 kg and 30% respectively. After FLS-IGM, median mature weight was 19 kg and mortality rate decreased from 30% to 11.11%. Likewise, fewer goat diseases were observed by farmers who were able to undergo FLS-IGM. With regard to income, there was a 127.34% difference on the median net income derived by farmers. Result implies that improved SC could lead not only to increased productivity and income of backyard goat raisers but also to better animal welfare.

Plasma CD147 reflects histological features in patients with lupus nephritis.

OBJECTIVE: A glycosylated transmembrane protein, CD147, has been implicated in regulating lymphocyte responsiveness and leukocyte recruitment. As lupus nephritis (LN) often follows a relapsing-remitting disease course, accurate understanding of the disease activity would be extremely helpful in improving prognosis. Unfortunately, neither clinical nor serological data can accurately reflect the histological features of LN. The present study investigated whether CD147 can accurately predict pathological features of LN. METHODS: Plasma and spot urine samples were collected from 64 patients who underwent renal biopsy between 2008 and 2011. Disease activity for LN tissues was evaluated using the biopsy activity index, and compared to levels of biomarkers including CD147. RESULTS: In LN tissues, CD147 induction was striking in injured glomeruli and infiltrating inflammatory cells, but not in damaged tubules representing atrophy. Plasma CD147 levels accurately reflected the histological disease activity. However, prediction using a single molecule would be quite difficult because of the complex pathogenesis of LN. The diagnostic accuracy of multiplex parameters indicated that the combination including plasma CD147 might yield excellent diagnostic abilities for guiding ideal LN therapy. CONCLUSION: Plasma CD147 levels might offer useful insights into disease activity as a crucial biomarker in patients with LN.

Effects of acivicin on growth, mycotoxin production and virulence of phytopathogenic fungi.

Acivicin is an inhibitor of γ-glutamyl transpeptidase and glutamine amidotransferase. When grown on a synthetic minimal agar medium, acivicin strongly inhibited the growth of Magnaporthe oryzae and Alternaria brassicicola, and to a lesser extent, Botrytis cinerea. However, only partial or marginal growth inhibition was observed with regard to Fusarium sporotrichioides and Fusarium graminearum. The growth retardation caused by acivicin was significantly alleviated by cultivating the fungus on a nutrient-rich medium. The inhibition of M. oryzae growth caused by 1 µmol l(-1) of acivicin on minimal agar medium was subdued by the addition of specific single amino acids, including His, a branched-chain amino acid (Leu, Ile or Val), an aromatic amino acid (Trp, Tyr or Phe), Met or Gln, at a concentration of 0·4 mmol l(-1). Trichothecene production by F. graminearum in trichothecene-inducing liquid medium was reduced significantly in the presence of acivicin despite its inability to inhibit growth in the trichothecene-inducing liquid medium. Foliar application of conidia in the presence of acivicin reduced the severity of rice blast disease caused by M. oryzae. These results suggest the usefulness of this modified amino acid natural product to mitigate agricultural problems caused by some phytopathogenic fungi. Significance and impact of the study: Fusarium head blight or scab disease and rice blast, caused by Fusarium graminearum and Magnaporthe oryzae, respectively, are major diseases of cereal crops that cause a significant loss of yield and deterioration in the quality of the grain. The present study investigated the effects of acivicin, a glutamine amino acid analog, on the physiology of various phytopathogenic fungi. Application of acivicin to a fungal culture and conidial suspension reduced mycotoxin production by the wheat scab fungus and the severity of rice blast, respectively. These results suggest the possibility that acivicin may serve as a lead compound to develop agricultural chemicals for the control of some plant diseases.

The impact of the number of occult metastatic lymph nodes on postoperative relapse of resectable esophageal cancer.

Clinical stage II/III esophageal cancer (EC), as defined by the Japanese Classification, relapses at a moderately high rate even after curative resection. The number of lymph node metastases is known to be associated with tumor relapse. Recently, the prognostic significance of occult metastatic lymph nodes (MLNs), as well as that of overt MLNs, has been reported. The aim of this study was to investigate the impact of the total number of MLNs including occult MLNs on postoperative relapse in clinical stage II/III EC. One hundred and five patients with clinical stage II/III EC who underwent esophagectomy accompanied by radical lymphadenectomy at the Department of Surgical Oncology in Osaka City University Hospital between January 2000 and October 2008 were included in this study. Occult MLNs, metastases not detected by hematoxylin-eosin staining, were identified by immunohistochemistry (IHC) using antipancytokeratin antibody AE1/AE3. The clinicopathological features of occult MLNs were compared between the relapse and no relapse groups. A total of 6558 lymph nodes (1357 from two-field dissection and 5201 from three-field dissection) were examined by IHC staining; 362 overt MLNs and 143 occult MLNs were detected. The number of occult MLNs increased in proportion to the International Union Against Cancer pathological (p)N-status and pStage. When the number of occult MLNs was added to the number of pNs, the number of total MLNs was associated with postoperative relapse. With respect to tumor, node, metastasis stage, 6 of 22 patients (27%) who were pathological node-negative converted to node-positive by considering total MLNs. The number of N3 patients with relapse increased markedly with restaging by total MLNs. The number of total MLNs, but not overt MLNs, was an independent prognostic factor on multivariate analysis. These results suggest that occult MLNs were often found, and they were associated with postoperative relapse of resectable esophageal cancer. The total number of MLNs including occult MLNs could contribute to evaluating the precise stage of patients with esophageal cancer.

First demonstration of MC-EDFA-repeatered SDM transmission of 40 x 128-Gbit/s PDM-QPSK signals per core over 6,160-km 7-core MCF.

We demonstrate the first 7-core multicore erbium-doped fiber amplified (MC-EDFA) transmission of 40 x 128-Gbit/s PDM-QPSK signals over 6,160-km 7-core multicore fiber (MCF). The crosstalk (XT) from all of the other 6 cores of a MC-EDFA and a 55-km length MCF are about -46.5 dB and -45.6 dB at center core, respectively. The core-to-core rotation approach at every amplified span is used to average the XT of all cores. The averaged optical signal-to-noise ratio (OSNR) after 6,160-km transmission is 15.6 dB with 0.1 nm resolution bandwidth. The Q-factor of all 40 channels surpasses the threshold of the forward-error-correction of 6.4 dB with 1 dB margin after 6,160 km. The total net capacity is 28.8 Tbit/s per fiber and achieved capacity-distance product is 177 Pbit/s.km per fiber. We confirmed the feasibility of MC-EDFA repeatered systems for trans-oceanic transmission.

Assessment of skin test with varicella-zoster virus antigen for predicting the risk of herpes zoster.

The Shozu Herpes Zoster (SHEZ) Study was designed to clarify the incidence of and predictive and immunological factors for herpes zoster in a defined community-based Japanese population. As part of this series, a total of 5683 residents aged ≥50 years received a varicella-zoster virus (VZV) skin test with VZV antigen, and 48 h later, the erythema and oedema were assessed by measuring the longest diameter. The diameters of both the erythema and oedema decreased with the increasing age of the subject. Sixty-three subjects contracted herpes zoster within a year after receiving the VZV skin test. Analysis of the herpes zoster incidence rate vs. the skin test reaction revealed that the shorter the diameter of erythema or oedema, the greater the likelihood of herpes zoster. These results demonstrated that the VZV skin test is an excellent surrogate marker for predicting the risk of herpes zoster.

Porphyromonas gingivalis displays a competitive advantage over Aggregatibacter actinomycetemcomitans in co-cultured biofilm.

BACKGROUND AND OBJECTIVE: Biofilm formation occurs through the events of cooperative growth and competitive survival among multiple species. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are important periodontal pathogens. The aim of this study was to demonstrate competitive or cooperative interactions between these two species in co-cultured biofilm. MATERIAL AND METHODS: P. gingivalis strains and gingipain mutants were cultured with or without A. actinomycetemcomitans. Biofilms formed on glass surfaces were analyzed by crystal violet staining and colony counting. Preformed A. actinomycetemcomitans biofilms were treated with P. gingivalis culture supernatants. Growth and proteolytic activities of gingipains were also determined. RESULTS: Monocultured P. gingivalis strains exhibited a range of biofilm-formation abilities and proteolytic activities. The ATCC33277 strain, noted for its high biofilm-formation ability and proteolytic activity, was found to be dominant in biofilm co-cultured with A. actinomycetemcomitans. In a time-resolved assay, A. actinomycetemcomitans was primarily the dominant colonizer on a glass surface and subsequently detached in the presence of increasing numbers of ATCC33277. Detachment of preformed A. actinomycetemcomitans biofilm was observed by incubation with culture supernatants from highly proteolytic strains. CONCLUSION: These results suggest that P. gingivalis possesses a competitive advantage over A. actinomycetemcomitans. As the required biofilm-formation abilities and proteolytic activities vary among P. gingivalis strains, the diversity of the competitive advantage is likely to affect disease recurrence during periodontal maintenance.

Short-term outcomes of local correction of stoma prolapse with a stapler device.

BACKGROUND: The aim of the present study was to classify the short-term outcomes of local correction of stoma prolapse with a stapler device. METHODS: The medical records of 11 patients undergoing local correction of stoma prolapse using a stapler device were retrospectively reviewed. RESULTS: No mortality or morbidity was observed after the surgery. Median operative time was 35 min (range 15-75 min), and blood loss was minimal. Median duration of follow-up was 12 months (range 6-55 months). One of the 11 patients had a recurrent stoma prolapse. CONCLUSIONS: This technique can be a feasible, safe and minimally invasive correction procedure for stoma prolapse.

Genetic variation of Gongylonema pulchrum from wild animals and cattle in Japan based on ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes.

The gullet worm (Gongylonema pulchrum) has been recorded from a variety of mammals worldwide, including monkeys and humans. Due to its wide host range, it has been suggested that the worm may be transmitted locally to any mammalian host by chance. To investigate this notion, the ribosomal RNA gene (rDNA), mainly regions of the internal transcribed spacers (ITS) 1 and 2, and a cytochrome c oxidase subunit I (COI) region of mitochondrial DNA of G. pulchrum were characterized using parasites from the following hosts located in Japan: cattle, sika deer, wild boars, Japanese macaques, a feral Reeves's muntjac and captive squirrel monkeys. The rDNA nucleotide sequences of G. pulchrum were generally well conserved regardless of their host origin. However, a few insertions/deletions of nucleotides along with a few base substitutions in the ITS1 and ITS2 regions were observed in G. pulchrum from sika deer, wild boars and Japanese macaques, and those differed from G. pulchrum in cattle, the feral Reeves's muntjac and captive squirrel monkeys. The COI sequences of G. pulchrum were further divided into multiple haplotypes and two groups of haplotypes, i.e. those from a majority of sika deer, wild boars and Japanese macaques and those from cattle and zoo animals, were clearly differentiated. Our findings indicate that domestic and sylvatic transmission cycles of the gullet worm are currently present, at least in Japan.

stx genotype and molecular epidemiological analyses of Shiga toxin-producing Escherichia coli O157:H7/H- in human and cattle isolates.

The relationship between human diseases caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) O157 strains and O157 strains isolated from cattle was investigated in an area where stockbreeding is prolific. For this purpose, the stx genotypes, the molecular epidemiological characteristics of 268 STEC O157 strains including 211 human-origin strains and 57 cattle-origin strains, and clinical manifestations of 210 STEC-infected people were analyzed. Of 211 human-origin strains, 92 strains (44%) were of the stx1/stx2 genotype, and 74 strains (35%) were of the stx2c genotype. Most of the people infected with stx2c genotype strains presented no symptoms or mild symptoms such as slight diarrhea, except for 3 patients with bloody diarrhea. Of the 57 cattle-origin strains, 27 strains (47%) were of the stx2c genotype and 17 strains (30%) were of the stx1/stx2 genotype. Pulsed-field gel electrophoresis (PFGE) and insertion sequence (IS) analysis demonstrated that 11 isolates (41%) of the 27 cattle isolates of the stx2c genotype had high homology (>95% identity) with human isolates. These results suggest that some genetic patterns of the stx2c genotype strains might be preserved in cattle or their surrounding environment for several years, and during these periods, they might have opportunities to infect people through various routes. Because of the mild virulence of the stx2c genotype strains, they seemed to be transmitted asymptomatically from cattle to humans and then spread from person to person. It may be a public health concern. Further, they occasionally cause severe symptoms in humans; therefore, caution is warranted for infections by stx2c genotype O157 strains, in addition to stx2-possessing genotype O157 strains.