Search

Core-shell GaInN/GaN multiquantum shell (MQS) nanowires (NWs) are gaining great attention for high-efficiency micro-light-emitting diodes (micro-LEDs) owing to the minimized etching region on their sidewall, nonpolar or semipolar emission planes, and ultralow density of dislocations. In this study, we evaluated the changes in NW morphologies and the corresponding device properties induced by GaInN/GaN superlattice (SL) structures. The cathodoluminescence intensities of the samples with 20 and 40 pairs of SLs were about 2.2 and 3.4 times higher, respectively, than that of the sample without SLs. The high-resolution scanning transmission electron microscopy (STEM) inspection confirmed that the high growth temperature of SLs prevented growth in the semipolar plane region close to the n-GaN core. A similar phenomenon was also observed for the GaN quantum barriers of the semipolar MQS region under a high growth temperature of 810 °C. This phenomenon was ascribed to the passivation of the semipolar plane surface by hydrogen atoms and the high probability of decomposition through NH

GaInN/GaN multi-quantum-shell (MQS) nanowires (NWs) are gaining increasing attention as promising materials for developing highly efficient long-wavelength micro-light emitting diodes (LEDs). To improve the emission properties in GaInN/GaN MQS NWs, it is necessary to suppress the emission from the (0001) c-plane MQS at the apex region, which featured with low crystalline quality. In this study, we investigated the enhancement of optical properties and the realization of micro-LEDs by confirming the effect of the (0001) plane region. A 7.9-fold enhancement of the electroluminescence (EL) intensity was demonstrated by removal the (0001) plane region via inductively coupled plasma (ICP) dry etching, owing to the promoted current injection into the (1–101) semi-polar and (10–10) non-polar sidewall area. To investigate the effect of the emission area on the samples with and without truncated (0001) plane region, devices with three different mesa areas (50 × 50, 100 × 100, and 100 × 200 μm2) were fabricated. An increased EL intensity with the reduced mesa areas was observed in the samples without dry etching of the (0001)-plane area, because more current can be injected into the sidewall region with higher crystalline quality and luminous efficiency than the (0001)-plane MQS. Under the same injection current density, the truncated samples’ light output was increased for more than ten times as compared to the samples without (0001)-plane etching. Therefore, it confirms the possibility of realizing highly efficient GaInN/GaN MQS NWs LEDs by eliminating the (0001) plane MQS region. A precise etching and surface passivation of the apex region is expected to further reduce the reverse leakage current and improve the performance in NW-LEDs.

Although the biliary system is generally aseptic, gallbladder microbiota has been reported in humans and some animals apart from dogs. We screened and analyzed the bacterial deoxyribonucleic acid in canine gallbladders using bile sampled from 7 healthy dogs and 52 dogs with liver- or gallbladder-associated disease. PCR screening detected bacteria in 17.3% of diseased dogs (9/52) and none in healthy dogs. Microbiota analysis of PCR-positive samples showed that the microbial diversity differed between liver- and gallbladder-associated disease groups. Thus, a specific bacterial community appears to occur at a certain frequency in the bile of diseased dogs.

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.

Creative Arts Educ Ther (2018) 4(2):118–130 DOI: 10.15212/CAET/2018/4/19 A Living Quilt: The Journey of a Cohort of Emerging Arts Therapists in Aotearoa Abstract This article traces the collaborative creation of a final gift–a symbolic weighted quilt–recently given by a cohort of third year trainee arts therapists to their faculty and fellow students. The article uses poetry and narrative to present and explore the process of this group of emerging arts therapists being woven together via their experiences of creativity, uncertainty and trust during their time on the Master of Arts in Arts Therapy program. It notes the interconnectivity between the singular and shared identities found during this journey, and explores the precious, expansive, and universal nature of the arts therapy experience and profession. This creative collaboration is a representation of the experience of student arts therapists who, having been soaked in the heavy liquids of creative encounters and felted together as a community, are now on the cusp of taking this deep fluid identity and experience out into the wider community.

Urinary tract infections (UTIs) are among the most common outpatient infections, with a lifetime incidence of around 60% in women. We analysed urine samples from 223 patients with community-acquired UTIs and report the presence of the cleavage product released during the synthesis of colibactin, a bacterial genotoxin, in 55 of the samples examined. Uropathogenic Escherichia coli strains isolated from these patients, as well as the archetypal E. coli strain UTI89, were found to produce colibactin. In a murine model of UTI, the machinery producing colibactin was expressed during the early hours of the infection, when intracellular bacterial communities form. We observed extensive DNA damage both in umbrella and bladder progenitor cells. To the best of our knowledge this is the first report of colibactin production in UTIs in humans and its genotoxicity in bladder cells., Author summary Colibactin is a bacterial genotoxin suspected of being involved in cancer. So far, the focus has been on colorectal cancer following asymptomatic intestinal carriage of genotoxic Escherichia coli. Here, we show for the first time that this genotoxin is produced in humans, by detecting it in the urine of patients suffering from urinary tract infections. We subsequently show in a rodent UTI model the genotoxic activity of colibactin in the bladder, including in regenerative cells. These results raise the hypothesis of a role of UTI in bladder cancer, which could be an interesting perspective for future investigation.

Objectives The Escherichia coli O25-ST131 clone is responsible for global dissemination of the blaCTX-M gene. However, the prevalence of this clone in the digestive tract, devoid of antimicrobial selection, and its molecular epidemiology remain unclear. In this study, we examined the origin of blaCTX-M-positive E. coli O25-ST131 and its distribution. Methods We separately sequenced the chromosomal and plasmid genomes of 50 E. coli O25 isolates obtained from faecal samples of patients with diarrhoea in Japan. Results Although 36 (72%) of 50 E. coli O25 isolates were ST131, only 6 harboured blaCTX-M. According to the fimH and ybbW sequences and fluoroquinolone susceptibility, H30R1 isolates were dominant (27/36; 75%) and possessed IncFII-FIA-FIB with FAB formula subtype F1:A2:B20 plasmids at a high frequency (24/27; 89%). The F1:A2:B20 plasmids possessed more resistance genes such as blaTEM-1, aminoglycoside resistance genes and trimethoprim/sulfamethoxazole resistance genes compared with non-F1:A2:B20 plasmids. In contrast, only one blaCTX-M-14 gene was located on the F1:A2:B20 plasmids, whereas the other three were located on IncFII (F4:A-:B-) (n = 1) and IncZ (n = 2) plasmids. Two H30Rx-ST131 isolates harboured blaCTX-M-15: one was on the chromosome and the other on the IncFIA-R plasmid. The stability and conjugation ability of the F1:A2:B20 plasmids were compared with those of non-F1:A2:B20 plasmids, which revealed higher stability but lower conjugative ability. Conclusions These results suggest that E. coli H30R1-ST131 is a multidrug-resistant clone containing several resistance genes in the F1:A2:B20 plasmid, which were widely distributed before the acquisition of blaCTX-M.

Here, we report a bacterium-isolated as the sole pathogen from a child with diarrhea-harboring eae and 2 different cytolethal distending toxin genes (cdt) that are homologous to Escherichia coli cdt-I and cdt-II. The bacterium was originally identified as atypical E. coli by conventional biochemical testing, but was finally identified as E. albertii by multilocus sequence analysis, which is the only method that can currently differentiate E. albertii from E. coli. The Shiga toxin 2f (stx2f) genes were also detected in the strain. Production of these 3 toxins was confirmed by western blotting and/or a cytotoxicity assay using eukaryotic cell lines. This is the first report showing the biological activity of CDT-I, CDT-II, and Stx2f in E. albertii.

Dogs are model animals that can be used to study the gut microbiome. Although the gut microbiome is assumed to be closely related to aging, information pertaining to this relationship in dogs is limited. Here, we examined the association between the canine gut microbiome and age via a bacterial 16S rRNA gene amplicon sequence analysis in a colony of 43 Japanese purebred Shiba Inu dogs. We found that microbial diversity tended to decrease with aging. A differential abundance analysis showed an association of a single specific microbe with aging. The age-related coabundance network analysis showed that two microbial network modules were positively and negatively associated with aging, respectively. These results suggest that the dog gut microbiome is likely to vary with aging.

The objectives of this study were to investigate prevalence and pathogenic potential of Escherichia coli contaminating raw milk and its products in Egypt. Out of 187 dairy products including 72 raw milk samples, 55 Karish cheese and 60 Ras cheese, 222 E. coli isolates including 111, 89 and 22 were obtained from 55 raw milk samples (76.4%), 41 Karish cheese (74.5%), and 13 Ras cheese (21.7%), respectively. Isolated E. coli strains were examined for 24 representative virulence genes present in diarrheagenic E. coli (DEC) and extraintestinal pathogenic E. coli (ExPEC). Among DEC and ExPEC virulence factors, genes for enteropathogenic E. coli (eaeA, bfpA, EAF), enterohemorrhagic E. coli (stx1, stx2, eaeA), enterotoxigenic E. coli (elt, est), enteroinvasive E. coli (invE), enteroaggregative E. coli (Eagg, astA), diffusely adherent E. coli (daaD), ExPEC (cdt-I to cdt-V, cnf1, cnf2, hlyA) and putative adhesins (efa1, iha, ehaA, saa, and lpfAO113) were screened by colony hybridization assay. Out of 222 E. coli strains, 104 (46.8%) isolated from 69 (36.9%) samples carried one or more virulence genes. The most prevalent gene detected was lpfAO113 (40.5%), followed by ehaA (32.4%,), astA (3.15%,), iha (1.80%), hlyA (1.35%), stx1 (0.90%), stx2 (0.90%), eaeA (0.45%), cdt-III (0.45%) and cnf2 (0.45%). Two strains isolated from Karish cheese harbored 5 virulence genes (stx1, stx2, iha, ehaA, lpfAO113). Stx subtype was determined to be stx1 (not stx1c or stx1d) and stx2d. Indeed, expression of hemolysin A, CDT-III, CNF-II, Stx1 and Stx2d was confirmed by blood agar plate, cytotoxicity assay and Western blotting, respectively. Among the 222 E. coli strains, 54 (48.6%), 38 (42.6%) and 12 (54.7%) isolated from raw milk, Karish cheese and Ras cheese were potentially virulent, respectively. O-genotyping indicated that most of the potentially virulent E. coli isolates did not belong to clinically important O serogroups except O75, O91 and O166, which have been associated with human diseases. Phylogenetic grouping revealed that 150 (67.6%), 67 (30.2%) and 5 (2.30%) strains were clustered into A, B1 and D groups, respectively, which are considered to be associated with intestinal infection, indicating that these E. coli strains might have a potential to cause gastroenteritis. To the best of our knowledge, this is the first comprehensive study regarding prevalence and pathogenic potential of E. coli in dairy products in Egypt. Raw milk, Karish cheese and Ras cheese in Egypt are highly contaminated with E. coli including potentially pathogenic strains, which may impose a public health threat.

Infection of cattle by bovine leukemia virus (BLV) causes significant economic losses in terms of milk and meat production in many countries. Because the gut microbiota may be altered by immunomodulation resulting from viral infections, we hypothesized that latent BLV infection would change the gut (i.e., rumen and hindgut) microbiota of infected cattle. In this study, we compared the gut microbiota of 22 uninfected and 29 BLV-infected Holstein-Friesian cows kept on the same farm, by 16S rRNA amplicon sequence analysis of fecal samples. First, we found that the fecal microbial diversity of BLV-infected cows differed slightly from that of uninfected cows. According to differential abundance analysis, some bacterial taxa associated with ruminal fermentation, such as Lachnospiraceae and Veillonellaceae families, were enriched in the fecal microbiota of uninfected cows. Second, the virus propagation ability of BLV strains was examined in vitro, and the correlation of the fecal microbiota with this virus propagation ability was analyzed. Higher virus propagation was shown to lead to less diversity in the microbiota. Differential abundance analysis showed that one bacterial taxon of genus Sanguibacteroides was negatively correlated with the virus propagation ability of BLV strains. Considering these results, BLV infection was speculated to decrease energy production efficiency in the cows via modification of rumen and hindgut microbiota, which partly relies on the virus propagation ability of BLV strains. This may explain the secondary negative effects of BLV infections such as increased susceptibility to other infections and decreased lifetime milk production and reproductive efficiency.

Bacteria of the genus Providencia are opportunistic pathogens of clinical significance due to their association with diarrhea and urinary tract infections. The present study was conducted to examine the prevalence and antimicrobial resistance of Providencia spp. in retail meats sold in Guangzhou, China and Osaka, Japan. Out of 158 meat samples including beef, pork and chicken, 67 Providencia (42%) belonging to four species viz., P. alcalifaciens, P. rustigianii, P. stuartii and P. rettgeri were isolated, and most of them were resistant to tetracycline (91%) followed by ampicillin (69%) and streptomycin (49%). Of 67 isolates, 29 (43%) were MDR, which is defined to be resistant to more than three classes of antimicrobials. No statistically significant differences were observed between Chinese and Japanese retail meat samples regarding contamination rate of Providencia spp. as well as frequency of the antimicrobial resistance of the isolates including MDR. Class 1 and/or class 2 integrons were detected in six of the eight isolates that were resistant to more than 4 antimicrobials, however none of the isolates harbored class 3 integron. A P. rustigianii harboring the blaOXA-10 gene was isolated, which is the first report of Providencia with blaOXA-10 gene of food origin. These data suggest that retail meats in China and Japan are substantially contaminated with Providencia spp., which displayed a high frequency of antimicrobial resistance, and establishing the surveillance of Providencia spp., especially antimicrobial resistant one, in retail meats is imperative.

In this study, we evaluated and compared the antibacterial activity of chlorine dioxide (ClO2) and sodium hypochlorite (NaClO) on various multidrug-resistant strains in the presence of bovine serum albumin and sheep erythrocytes to mimic the blood contamination that frequently occurs in the clinical setting. The 3 most important species that cause nosocomial infections, i.e., methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (MDRP), and multidrug-resistant Acinetobacter baumannii (MDRA), were evaluated, with three representative strains of each. At a 10-ppm concentration, ClO2 drastically reduced the number of bacteria of all MDRP and MDRA strains, and 2 out of 3 MRSA strains. However, 10 ppm of NaClO did not significantly kill any of the 9 strains tested in 60 seconds (s). In addition, 100 ppm of ClO2 completely killed all MRSA strains, whereas 100 ppm of NaClO failed to significantly lower the number of 2 MRSA strains and 1 MDRA strain. A time-course experiment demonstrated that, within 15 s, 100 ppm of ClO2, but not 100 ppm of NaClO, completely killed all tested strains. Taken together, these data suggest that ClO2 is more effective than NaClO against MRSA, MDRP, and MDRA, and 100 ppm is an effective concentration against these multidrug-resistant strains, which cause fatal nosocomial infections.

Background: Inhibition of the renin-angiotensin system (RAS) has been used to treat diabetic nephropathy. However, RAS inhibition increases the risk of renal complications. In this study, we evaluated the effect of combining RAS inhibitor treatment with beraprost sodium (BPS), a prostaglandin I2 analog, in diabetic nephropathy with arteriosclerosis obliterans. Methods: This study was a prospective, randomized, open-label study. Twenty-six Japanese patients (age >30 years) with diabetic nephropathy and arteriosclerosis obliterans were randomly assigned to the BPS group (n=13), which received the combination of an RAS inhibitor and BPS (120 μg day) therapy, or the control group (n=13), which received only an RAS inhibitor. Patients were followed up for 1 year. The primary endpoint was the effect of BPS on renal function. Results: In the control group, serum creatinine (1.64±0.87 to 2.34±1.53 mg dL, p

Extranodal natural killer/T-cell lymphoma (ENK/TCL) is most often in the nose or the nasopharynx but can present elsewhere. We report a rare case of ENK/TCL that presented as swelling of an upper eyelid without ocular involvement. A 76-year-old man visited our hospital with a swollen lesion of the left upper eyelid which had appeared 2 months earlier. A biopsy of the upper eyelid revealed slight perivascular and periadnexal infiltration of mononuclear cells with dermal edema. Treatment with oral prednisolone at a dosage of 20 mg/day decreased the eyelid swelling. However, 5 months later, exacerbation of the swelling and nasal congestion were observed. A second biopsy of the upper eyelid revealed a diffuse dermal infiltrate composed of mononuclear cells with an angiocentic growth pattern. Immunohistochemical studies and in situ hybridization showed natural killer-lineage antigens (CD56, granzyme B, and T-cell intracellular antigen 1) with expression of Epstein-Barr virus. These findings lead to the diagnosis of ENK/TCL. We treated the patient with radiation therapy (50 Gy) and 3 courses of a regimen including dexamethasone, carboplatin, etoposide, and ifosphamide. This case suggests that ENK/TCL can present with swelling of an upper eyelid as the primary sign of the skin lesion. Swelling of an upper eyelid should be considered in the differential diagnosis of ENK/TCL.

In the present study, we examined the prevalence of Providencia spp. in retail meats and in stool samples from diarrheal patients in Thailand. Providencia-specific (Psp)-PCR amplification was positive for 58% (15/26) of the chicken, 64% (16/25) of the pork, and 68% (17/25) of the beef samples. Subsequently, Providencia strains were isolated from 65% (17/26) of the chicken, 68% (17/25) of the pork, and 72% (18/25) of the beef samples. Although P. alcalifaciens (40-58%) was the most prevalent Providencia strain, P. rettgeri, P. stuartii, and P. rustigianii were also isolated. Of the patient stool samples tested, 7.5% (16/214) had Psp-PCR products, of which 4 were P. alcalifaciens (1.9%), 4 were P. rettgeri (1.9%), and 1 was P. stuartii (0.5%). In conclusion, retail meats were substantially contaminated with Providencia, especially P. alcalifaciens. Therefore, retail meats are possibly the source of Providencia infections in humans.

A multiple DNA inversion system, the shufflon, exists in incompatibility (Inc) I1 and I2 plasmids. The shufflon generates variants of the PilV protein, a minor component of the thin pilus. The shufflon is one of the most difficult regions for de novo genome assembly because of its structural diversity even in an isolated bacterial clone. We determined complete genome sequences, including those of IncI2 plasmids carrying mcr-1, of three Escherichia coli strains using single-molecule, real-time (SMRT) sequencing and Illumina sequencing. The sequences assembled using only SMRT sequencing contained misassembled regions in the shufflon. A hybrid analysis using SMRT and Illumina sequencing resolved the misassembled region and revealed that the three IncI2 plasmids, excluding the shufflon region, were highly conserved. Moreover, the abundance ratio of whole-shufflon structures could be determined by quantitative structural variation analysis of the SMRT data, suggesting that a remarkable heterogeneity of whole-shufflon structural variations exists in IncI2 plasmids. These findings indicate that remarkable rearrangement regions should be validated using both long-read and short-read sequencing data and that the structural variation of PilV in the shufflon might be closely related to phenotypic heterogeneity of plasmid-mediated transconjugation involved in horizontal gene transfer even in bacterial clonal populations.

We screened mcr-1 and mcr-2 genes in 9,306 Escherichia coli strains isolated from healthy animals in the Japanese Veterinary Antimicrobial Resistance Monitoring (JVARM) system. mcr-1 was detected in 39 strains (5, 20, and 14 strains isolated from cattle, swine, and broilers, respectively), whereas mcr-2 was not detected. mcr-2 was also not detected with the investigation sequence homology search against our curated GenEpid-J database.

Here, we report a bacterium-isolated as the sole pathogen from a child with diarrhea-harboring eae and 2 different cytolethal distending toxin genes (cdt) that are homologous to Escherichia coli cdt-I and cdt-II. The bacterium was originally identified as atypical E. coli by conventional biochemical testing, but was finally identified as E. albertii by multilocus sequence analysis, which is the only method that can currently differentiate E. albertii from E. coli. The Shiga toxin 2f (stx2f) genes were also detected in the strain. Production of these 3 toxins was confirmed by western blotting and/or a cytotoxicity assay using eukaryotic cell lines. This is the first report showing the biological activity of CDT-I, CDT-II, and Stx2f in E. albertii.

International audience; Various forms of cancer have been linked to the carcinogenic activities of microorganisms(1-3). The virulent gene island polyketide synthase (pks) produces the secondary metabolite colibactin, a genotoxic molecule(s) causing double-stranded DNA breaks(4) and enhanced colorectal cancer development(5,6). Colibactin biosynthesis involves a prodrug resistance strategy where an N-terminal prodrug scaffold (precolibactin) is assembled, transported into the periplasm and cleaved to release the mature product(7-10). Here, we show that ClbM, a multidrug and toxic compound extrusion (MATE) transporter, is a key component involved in colibactin activity and transport. Disruption of clbM attenuated pks+ E. coli-induced DNA damage in vitro and significantly decreased the DNA damage response in gnotobiotic Il10(-/-) mice. Colonization experiments performed in mice or zebrafish animal models indicate that clbM is not implicated in E. coli niche establishment. The X-ray structure of ClbM shows a structural motif common to the recently described MATE family. The 12-transmembrane ClbM is characterized as a cation-coupled antiporter, and residues important to the cation-binding site are identified. Our data identify ClbM as a precolibactin transporter and provide the first structure of a MATE transporter with a defined and specific biological function.

Cytolethal distending toxins (CDTs), which block eukaryotic cell proliferation by acting as inhibitory cyclomodulins, are produced by diverse groups of Gram-negative bacteria. Active CDT is composed of three polypeptides—CdtA, CdtB, and CdtC—encoded by the genes cdtA , cdtB , and cdtC , respectively. We developed a PCR-restriction fragment length polymorphism assay for the detection and differentiation of five alleles of cdtB (Cdt-I through Cdt-V) in Escherichia coli and used the assay to investigate the prevalence and characteristic of CDT-producing E. coli in children with diarrhea (A. Hinenoya et al., Microbiol. Immunol. 53:206–215, 2009). In these assays, two untypable cdtB genes were detected and the organisms harboring the cdtB gene were identified as Providencia alcalifaciens (strains AH-31 and AS-1). Nucleotide sequence analysis of the cdt gene cluster revealed that the cdtA , cdtB , and cdtC genes of P. alcalifaciens are of 750, 810, and 549 bp, respectively. To understand the possible horizontal transfer of the cdt genes among closely related species, the presence of cdt genes was screened in various Providencia spp. by colony hybridization assay, and the cdt gene cluster was found in only limited strains of P. alcalifaciens . Genome walking revealed that the cdt gene cluster of P. alcalifaciens is located adjacent to a putative transposase gene, suggesting the locus might be horizontally transferable. Interestingly, the CDT of P. alcalifaciens (PaCDT) showed some homology with the CDT of Shigella boydii . Whereas filter-sterilized lysates of strains AH-31 and AS-1 showed distention of CHO but not of HeLa cells, E. coli CDT-I exhibited distention of both cells. This activity of PaCDT was confirmed by generating recombinant PaCDT protein, which could also be neutralized by rabbit anti-PaCdtB antibody. Furthermore, recombinant PaCDT was found to induce G 2 /M cell cycle arrest and phosphorylation of host histone H2AX, a sensitive marker of DNA double-strand breaks. To our knowledge, this is the first report showing that certain clinical P. alcalifaciens strains could produce variants of the CDTs compared.

In the present study, we examined the prevalence of Providencia spp. in retail meats and in stool samples from diarrheal patients in Thailand. Providencia-specific (Psp)-PCR amplification was positive for 58% (15/26) of the chicken, 64% (16/25) of the pork, and 68% (17/25) of the beef samples. Subsequently, Providencia strains were isolated from 65% (17/26) of the chicken, 68% (17/25) of the pork, and 72% (18/25) of the beef samples. Although P. alcalifaciens (40-58%) was the most prevalent Providencia strain, P. rettgeri, P. stuartii, and P. rustigianii were also isolated. Of the patient stool samples tested, 7.5% (16/214) had Psp-PCR products, of which 4 were P. alcalifaciens (1.9%), 4 were P. rettgeri (1.9%), and 1 was P. stuartii (0.5%). In conclusion, retail meats were substantially contaminated with Providencia, especially P. alcalifaciens. Therefore, retail meats are possibly the source of Providencia infections in humans.

In this study, we evaluated and compared the antibacterial activity of chlorine dioxide (ClO2) and sodium hypochlorite (NaClO) on various multidrug-resistant strains in the presence of bovine serum albumin and sheep erythrocytes to mimic the blood contamination that frequently occurs in the clinical setting. The 3 most important species that cause nosocomial infections, i.e., methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (MDRP), and multidrug-resistant Acinetobacter baumannii (MDRA), were evaluated, with three representative strains of each. At a 10-ppm concentration, ClO2 drastically reduced the number of bacteria of all MDRP and MDRA strains, and 2 out of 3 MRSA strains. However, 10 ppm of NaClO did not significantly kill any of the 9 strains tested in 60 seconds (s). In addition, 100 ppm of ClO2 completely killed all MRSA strains, whereas 100 ppm of NaClO failed to significantly lower the number of 2 MRSA strains and 1 MDRA strain. A time-course experiment demonstrated that, within 15 s, 100 ppm of ClO2, but not 100 ppm of NaClO, completely killed all tested strains. Taken together, these data suggest that ClO2 is more effective than NaClO against MRSA, MDRP, and MDRA, and 100 ppm is an effective concentration against these multidrug-resistant strains, which cause fatal nosocomial infections.

The consumption of raw milk cheese can expose populations to Shiga toxin-producing Escherichia coli (STEC). We report here the genome sequence of an E. coli O26:H11 strain isolated from humans during the first raw milk cheese outbreak described in France (2005).

In the present study, we examined the prevalence of Providencia spp. strains among children with diarrhea in Japan. We developed a Providencia genus-specific polymerase chain reaction (PCR) method, and the specificity and sensitivity was evaluated to be 100% with various bacterial strains including 7 genera and 13 species. Five of 345 samples (1.4%) were positive by PCR using a Providencia genus-specific primer targeting the 16S rRNA gene. The single species Providencia rettgeri was isolated from 4 stool samples of children with diarrhea. The prevalence of Providencia spp. in children with diarrhea in Japan is lower than that previously reported for Japanese travelers abroad with diarrhea.

A 79-year-old man with a 3-month history of lymphedema of the lower limbs, and diabetes mellitus, was admitted to our hospital for suspected deep venous thrombosis. Several hours after admission, leg pain and purpura-like skin color appeared. On the 2nd hospital day, he was referred to our department for possible acute occlusive peripheral artery disease (PAD) and skin necrosis with blisters; however, computed tomography with contrast showed no occlusive lesions. He had already developed shock and necrotizing deep soft-tissue infections of the left lower leg. Laboratory findings revealed renal dysfunction and coagulation system collapse. Soon after PAD was ruled out, clinical findings suggested necrotizing deep soft-tissue infections, shock state, disseminated intravascular coagulation, and multiple organ failure. These symptoms led to a high suspicion of the well-recognized streptococcal toxic shock syndrome (STSS). With a high suspicion of STSS, we detected Group G β-hemolytic streptococci (GGS) from samples aspirated from the leg bullae, and the species was identified as Streptococcus dysgalactiae subsp. equisimilis (SDSE) by 16S-ribosomal RNA sequencing. However, unfortunately, surgical debridement was impossible due to the broad area of skin change. Despite adequate antimicrobial therapy and intensive care, the patient died on the 3rd hospital day. The M-protein gene (emm) typing of the isolated SDSE was revealed to be stG6792. This type of SDSE is the most frequent cause of STSS due to GGS in Japan. We consider it to be crucial to rapidly distinguish STSS from acute occlusive PAD to achieve life-saving interventions in patients with severe soft-tissue infections.