著者

Atsushi Hinenoya Sharda Prasad Awasthi Noritomo Yasuda Ayaka Shima Hirofumi Morino Tomoko Koizumi Toshiaki Fukuda Takanori Miura Takashi Shibata Shinji Yamasaki

出版者

National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

vol.68, no.4, pp.276-279, 2015 (Released:2015-07-22)

参考文献数

16

被引用文献数

8 21

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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.

著者

Phuong Hoai HOANG Sharda Prasad AWASTHI Phuc DO NGUYEN Ngan Ly Hoang NGUYEN Dao Thi Anh NGUYEN Ninh Hoang LE Chinh VAN DANG Atsushi HINENOYA Shinji YAMASAKI

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.79, no.3, pp.479-485, 2017 (Released:2017-03-18)

参考文献数

51

被引用文献数

27

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In this study, we attempted to isolate Escherichia coli from healthy adults in Ho Chi Minh City, Vietnam, and characterized its antimicrobial resistance profile, extended-spectrum β-lactamase (ESBL) genotype, phylogenetic grouping and virulence gene profile. A total of 103 E. coli isolates were obtained, and most of them were antimicrobial resistant such to streptomycin (80.6%), tetracycline (67.0%), ampicillin (65.0%), sulfamethoxsazole/trimethoprim (48.5%), nalidixic acid (43.7%), chloramphenicol (34.0%), cefotaxime (15.5%), ciprofloxacin (15.5%), kanamycin (12.6%), ceftazidime (10.7%), fosfomycin (4.9%) and gentamicin (2.9%). However, all these E. coli strains were susceptible to imipenem. Surprisingly, of 103 strains, 74 (71.8%) and 43 (41.7%) strains showed resistance to more than 3 and 5 classes of antimicrobials, respectively. Furthermore, 10 E. coli strains were ESBL-producers and positive for blaCTX-M genes (7 for blaCTX-M-9 and 3 for blaCTX-M-1), while five were additionally positive for blaTEM genes. S1-nuclease pulsed-field gel electrophoresis analysis revealed that 7 and 3 strains of E. coli carry blaCTX-M genes on their large plasmid and chromosome, respectively. Phylogenetic analysis exhibited that majority of the E. coli strains was grouped into A (44.7%), followed by B1 (23.3%), B2 (18.4%) and D (13.6%). Virulence genes associated with diarrheagenic E. coli, such as astA, EAF, eaeA, elt and eagg were also detected in ESBL-producing E. coli as well as antimicrobial resistant strains. These data suggest that commensal E. coli of healthy human could be a reservoir for antimicrobial resistance determinants and some of them might be harmful to human.

著者

Srinuan SOMROOP Noritoshi HATANAKA Sharda Prasad AWASTHI Kentaro OKUNO Masahiro ASAKURA Atsushi HINENOYA Shinji YAMASAKI

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

vol.79, no.3, pp.683-691, 2017 (Released:2017-03-28)

参考文献数

31

被引用文献数

3

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Cytolethal distending toxin (CDT) consisting of CdtA, CdtB and CdtC has been reported to be a possible virulence factor of campylobacters including Campylobacter upsaliensis. In our previous study, the cdtB gene-based PCR-restriction fragment length polymorphism (RFLP) assay for detection and differentiation of 7 Campylobacter species yielded 3 different RFLP patterns (Cu-I to Cu-III). In this study, entire cdt (Cucdt) genes of each pattern were sequenced to see whether there are any differences in cdt genes, its amino acid sequences and biological activity of CuCDT. We found that all 3 representative strains harbor the entire Cucdt genes and homology between prototype and newly determined Cucdt genes was 94 to 98% with cdtA, 93 to 94% with cdtB and 92 to 93% with cdtC, while that between amino acids of CuCDT was 95 to 99% with CdtA, 97 to 98% with CdtB and 92 to 93% with CdtC. Furthermore, CDT activity produced by C. upsaliensis strains was examined by cytotoxicity assay with HeLa cells. Interestingly, C. upsaliensis produced 64 to 2,340 times higher CDT titer in comparison to other campylobacters did. In addition, Cu-III showed 64 times higher CDT titer than Cu-II, although CDT production level was almost the same by western blotting. These data suggest that CDT produced by C. upsaliensis might contribute more to human diseases in comparison to that produced by other campylobacters and Cu-III CDT seems to be more toxic to HeLa cells in comparison to Cu-I and Cu-II CDTs.

著者

Atsushi Hinenoya Sharda Prasad Awasthi Noritomo Yasuda Keigo Nagano Jayedul Hassan Keiji Takehira Noritoshi Hatanaka Shun Saito Takashi Watabe Miki Yoshizawa Haruna Inoue Shinji Yamasaki

出版者

National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

pp.JJID.2021.355, (Released:2021-08-31)

参考文献数

34

被引用文献数

10

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Escherichia albertii is an emerging zoonotic foodborne pathogen. Several outbreaks of E. albertii have occurred particularly in Japan. Although birds have been considered as one of the most important reservoirs of this bacterium, information regarding the prevalence in birds is still scanty. We performed a survey of E. albertii in wild birds in Japan, and examined characteristics of the isolates. E. albertii specific gene was detected in 5 cloacal swabs out of 156 birds by PCR. Four E. albertii were isolated from a swallow with 2 different E. albertii strains and 2 pigeons in a flock by XRM-MacConkey agar. These isolates were assigned to biogroup 3, shown no resistance to any antimicrobials tested, and classified into 2 EAO-genotypes (EAOg2 and EAOg33) and untypable. Similar to clinical E. albertii strains, these isolates carried virulence genes including eae (n=4), paa (n=4), Eccdt-I (n=2) and stx2f (n=1) in addition to Eacdt. Interestingly, stx2f genes in a strain were located on an inducible bacteriophage, which can confer the ability to produce Stx2f to E. coli. In conclusion, Japanese wild birds carried E. albertii at the similar levels to the reported prevalence in birds. These isolates may have a potential to cause gastroenteritis in humans.

著者

Atsushi Hinenoya Sharda Prasad Awasthi Noritomo Yasuda Ayaka Shima Hirofumi Morino Tomoko Koizumi Toshiaki Fukuda Takanori Miura Takashi Shibata Shinji Yamasaki

出版者

National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

pp.JJID.2014.294, (Released:2015-01-20)

参考文献数

16

被引用文献数

9 21

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In this study, we evaluated the antibacterial activity of chlorine dioxide (ClO2) compared with sodium hypochlorite (NaClO) on various multidrug-resistant strains in the presence of bovine serum albumin and sheep erythrocytes to mimic the frequent blood contamination in clinical environment. The 3 most important species causing nosocomial infections, i.e., methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Pseudomonas aeruginosa (MDRP) and multidrug-resistant Acinetobacter baumannii (MDRA) were evaluated, with 3 representative strains from each. At a 10 ppm-concentration, ClO2 drastically reduced the number of all MDRP and MDRA, and 2 out of 3 MRSA strains, but NaClO was unable to cause any remarkable attenuation for any of the 9 strains tested in 60 seconds. Increased concentration of 100 ppm enabled ClO2 to completely kill MRSA strains, whereas NaClO failed to significantly lower the number of 2 MRSA and 1 MDRA strains. A time-course experiment demonstrated that, within 15 seconds, 100 ppm of ClO2 could kill completely all tested strains but NaClO at this concentration failed to do so. Together, these data suggest that ClO2 is more effective than NaClO against MRSA, MDRP and MDRA, and 100 ppm could be a practical concentration of ClO2 against these multidrug-resistant strains, which may cause fatal nosocomial infections.

著者

Srinuan SOMROOP Noritoshi HATANAKA Sharda Prasad AWASTHI Kentaro OKUNO Masahiro ASAKURA Atsushi HINENOYA Shinji YAMASAKI

出版者

公益社団法人 日本獣医学会

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.16-0654, (Released:2017-02-16)

被引用文献数

3

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Cytolethal distending toxin (CDT) consisting of CdtA, CdtB and CdtC has been reported to be a possible virulence factor of campylobacters including C. upsaliensis. In our previous study, the cdtB gene-based PCR-restriction fragment length polymorphisms (RFLP) assay for detection and differentiation of 7 Campylobacter species yielded 3 different RFLP patterns (Cu-I to Cu-III). In this study, entire cdt (Cucdt) genes of each pattern were sequenced to see whether there are any differences in cdt genes, its amino acid sequences and biological activity of CuCDT. We found that all 3 representative strains harbor the entire Cupcdt genes and homology between prototype and newly determined Cucdt genes was 94 to 98% with cdtA, 93 to 94% with cdtB and 92 to 93% with cdtC, while that between amino acids of CuCDT was 95 to 99% with CdtA, 97 to 98% with CdtB and 92 to 93% with CdtC. Furthermore, CDT activity produced by C. upsaliensis strains was examined by cytotoxicity assay with HeLa cells. Interestingly, C. upsaliensis produced 64 to 2,340 times higher CDT titer in comparison to other campylobacters did. In addition, Cu-III showed 64 times higher CDT titer than Cu-II, although CDT production level was almost the same by western blotting. These data suggest that CDT produced by C. upsaliensis might contribute more to human diseases in comparison to that produced by other campylobacters and Cu-III CDT seems to be more toxic to HeLa cells in comparison to Cu-I and Cu-II CDTs.