Masanobu Onozaki - Academia.edu (original) (raw)

Papers by Masanobu Onozaki

Food Control, May 1, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Dairy Science, Aug 1, 2012

Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion ... more Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion of thin watery milk with white flakes. Prototheca zopfii has been biochemically and serologically divided into at least 2 genotypes, P. zopfii genotype 1 and P. zopfii genotype 2. The latter is known to be the main causative agent of bovine protothecal mastitis. Prototheca zopfii was later reclassified into 5 varieties: var. zopfii (genotypes 1 and 2), var. 1 (formerly Prototheca blaschkeae), var. 3 (formerly P. moriformis), and var. portoricensis. In this study, the 18S ribosomal DNA sequences of diverse clinical specimens from different areas in Japan were studied to clarify the pathogenicity of P. zopfii var. zopfii. The phylogenetic tree revealed that all genotype 2 isolates were grouped in a cluster of P. zopfii var. zopfii SAG 2021 T (type strain genotype 2), and were independent from the cluster of the genotype 1 isolates. Thus, all isolates from bovine mastitis in Japan were identified as P. zopfii genotype 2. Therefore, P. zopfii var. zopfii genotype 2 is associated with bovine mastitis.

Journal of Dermatological Science, Apr 1, 2009

that the Tunisian families are likely linked to the previously identified critical 15q22–15q24 in... more that the Tunisian families are likely linked to the previously identified critical 15q22–15q24 interval. For families PPK3 and PPK4, no other cases could be investigated. Nevertheless, it is noteworthy that the two patients belonging to these families shared a common haplotype between markers D15S534 and D15S650. Parametric multipoint linkage analysis gave the maximum cumulative lod score value of 5.33 for marker D15S650. These results support genetic linkage of the PPK-families to the tested critical interval on 15q22–15q24. It is noteworthy that in family PPK2, individuals IV-1 and IV-2 born to a consanguineous marriage were homozygous for the interval between microsatellite markers D15S213 and D15S988; this segment is likely inherited from a common ancestor. As their mother III-2 was healthy, this suggests that the disease locus should be distal to marker D15S988. In the present study, we provide confirmatory evidence for the location of the punctate PPK in 15q22–15q24 although the precise gene interval should be reconsidered when compared to the study of Gao et al. that suggested that the disease is proximal to D15S988, based on recombinant healthy individuals [5]. To our knowledge, this is the first report of Buschke–Fischer– Brauer’s disease in North African families.

Nippon Ishinkin Gakkai Zasshi, 2008

Kansenshōgaku zasshi, 2009

Journal of Veterinary Medical Science, 2011

Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cur... more Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cure. Therefore, prevention is the best approach and this is best achieved through the use of effective disinfectants. The aim of this study was to evaluate the in vitro algaecide efficacy of conventional disinfectants against strains of P. zopfii genotype 1 and 2. The minimal algaecide concentration (MAC) of alkyldiaminoethylglycine hydrochloride, chlorhexidine, dioxide chlorine, povidone iodine and sodium hypochlorous acid against 10 isolates and the type strain (SAG2063 T) of P. zopfii genotype 1 as well as 10 isolates and the type strain (SAG2021 T) of P. zopfii genotype 2 were examined using the micro dilution method. This in vitro study indicated that alkyldiaminoethylglycine hydrochloride, chlorhexidine, povidone iodine and sodium hypochlorous acid, but not dioxide chlorine, are effective against both genotypes of P. zopfii.

Journal of Veterinary Medical Science, 2011

Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cur... more Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cure. Therefore, prevention is the best approach and this is best achieved through the use of effective disinfectants. The aim of this study was to evaluate the in vitro algaecide efficacy of conventional disinfectants against strains of P. zopfii genotype 1 and 2. The minimal algaecide concentration (MAC) of alkyldiaminoethylglycine hydrochloride, chlorhexidine, dioxide chlorine, povidone iodine and sodium hypochlorous acid against 10 isolates and the type strain (SAG2063 T) of P. zopfii genotype 1 as well as 10 isolates and the type strain (SAG2021 T) of P. zopfii genotype 2 were examined using the micro dilution method. This in vitro study indicated that alkyldiaminoethylglycine hydrochloride, chlorhexidine, povidone iodine and sodium hypochlorous acid, but not dioxide chlorine, are effective against both genotypes of P. zopfii.

Journal of Infection and Chemotherapy, Oct 1, 2014

This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed ... more This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed patient. The patient was a 62-year-old housewife who presented general malaise in April 2011. Hairy cell leukemia was highly suspected. Chemotherapy was started because the patient developed severe pancytopenia in October 2011. Itraconazole capsules (100 mg/day) and trimethoprim (320 mg/day) plus sulfamethoxazole (1600 mg/day) combinations were orally administered for prophylaxis of fungal infections. Of BacT/ALERT 3D FA aerobic culture bottles and FN anaerobic culture bottles, only FA aerobic blood culture bottles produced positive reactions when the patient developed fever in January 2012. Gramstaining of blood culture bottles revealed Gram-negative elliptical sporangia. Culturing on Sabouraud dextrose agar produced smooth and creamy white, yeast-like colonies. Partial DNA sequences of the nuclear 18S rDNA and 28S rDNA D1/D2 domains of the isolated strain were identical to those of P. zopfii genotype 2. The MICs and minimal lethal concentrations of antifungals revealed that it was susceptible to amphotericin B and itraconazole. The patient died, at which time plasma (1 / 3)-b-D-glucan was positive (131 pg/mL).

Medical Mycology, Feb 1, 2011

(GM), kanamycin (KM) and itraconazole (ITZ) [6-10]. However, in vitro susceptibility tests on the... more (GM), kanamycin (KM) and itraconazole (ITZ) [6-10]. However, in vitro susceptibility tests on the two P. zopfi i genotypes have not been well investigated. This is the fi rst study to assess the susceptibility of genotype 2 isolates from bovine mastitis and genotype 1 strains recovered from cow-barn surroundings. Materials and methods Strains The type P. zopfi i strain of genotype 1 (SAG2063 T) and genotype 2 (SAG2021 T) were used for susceptibility tests. In addition, 10 isolates of P. zopfi i genotype 2 were recovered from 10 cases of bovine protothecal mastitis in Japan. Ten isolates of P. zopfi i genotype 1 were obtained from Japanese farm stock [3]. These isolates were previously defi ned by an 18S rDNA-based genotype-specifi c PCR assay [3-5] (Table 1).

Journal of Medical Microbiology, 2008

Loop-mediated isothermal amplification (LAMP) is a novel, rapid nucleic acid amplification method... more Loop-mediated isothermal amplification (LAMP) is a novel, rapid nucleic acid amplification method with high specificity and sensitivity under isothermal conditions. In this study a LAMP assay for diagnosing Pneumocystis pneumonia (PCP) was developed. Oligonucleotide primers specific for Pneumocystis species were designed corresponding to 18S rRNA gene sequences. The assay, performed for 30 min at 61 6C, was capable of detecting 50 copies per tube (2¾10 3 copies ml "1) in 30 min and did not show cross-reactivity to other species of fungi, including the genera Candida, Aspergillus and Cryptococcus. A total of 21 of 24 clinical specimens (sputum and bronchoalveolar lavage fluid) from patients with suspected PCP tested positive using the LAMP assay by real-time fluorescence detection. The results of the LAMP reaction were also observed by real-time turbidity detection and end-point visual turbidity or fluorescence detection. With real-time fluorescence detection, melting curves of the products were effective at distinguishing specific amplification from non-specific amplification or self-amplification. Visual detection was also possible as a rapid and easy assay using only a heat block and a black light. Recently, a new specific DNA amplification technique called loop-mediated isothermal amplification (LAMP) was developed (Nagamine et al., 2002; Notomi et al., 2000), and has already been applied to the detection of pathogenic viruses (Poon et al., 2005), bacteria (Iwamoto et al., 2003), parasites (Poon et al., 2006) and fungi (Endo et al., 2004). LAMP, which does not involve the use of PCR, allows the rapid amplification of DNA with high specificity under isothermal conditions using DNA polymerase with

Kansenshōgaku zasshi, 2004

Japanese Journal of Infectious Diseases, 2013

In this study, a specific quantitative PCR system for the detection and identification of Prototh... more In this study, a specific quantitative PCR system for the detection and identification of Prototheca zopfii genotypes was developed using a TaqMan } MGB probe and ResoLight dye. The P. zopfii-specific primers 18PZF1 and 18PZR1 were generated on the basis of the alignment of the small subunit ribosomal DNA domain base sequences of the genera Chlorella and Prototheca obtained from DDBJ/EMBL/GenBank, and the TaqMan } MGB probe PZP1 was designed corresponding to this amplification region. Analysis of the melting curves of the amplicons using ResoLight dye was able to differentiate between P. zopfii genotypes 1 and 2. The specificity of this detection system was examined using strains from a culture collection (28 strains) and clinical isolates (140 strains). The TaqMan } MGB probe amplicon was detected only in reference strains of P. zopfii (n ＝ 12) and clinical isolates (n ＝ 135). Ninety-two clinical specimens from cows with mastitis (36 samples) and healthy controls (56 samples) were also tested. All isolates from milk samples (n ＝ 92) and clinical isolates (n ＝ 135) were identified as P. zopfii genotype 2.

Food Control

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Applied Microbiology, 2021

Aims The aim of the study was to develop a microarray-based method for the detection of antibioti... more Aims The aim of the study was to develop a microarray-based method for the detection of antibiotic-resistant Campylobacter in broiler farms to decrease the risk of contamination of chicken meat. Methods and Results A combination of DNA microarray and primer extension for rapid and simultaneous detection of fluoroquinolone- and macrolide-resistant Campylobacter jejuni/Campylobacter coli, termed Campylobacter Express Resistance Array (CAMERA), was used to analyse chicken caecal droppings. CAMERA assays could detect at least 105 colony forming units of C. jejuni/C. coli g−1 of chicken caecal contents spiked with C. jejuni/C. coli. To compare the CAMERA method and direct culturing method for screening antibiotic-resistant C. jejuni/C. coli in poultry farms, chicken caecal droppings obtained from 42 poultry houses were analysed using both methods. In total, 95.2% of the results (40/42 poultry houses) obtained using the CAMERA and culturing method were identical. In the remaining two poul...

Kansenshogaku Zasshi, 2009

Japanese Journal of Infectious Diseases, 2013

In this study, a specific quantitative PCR system for the detection and identification of Prototh... more In this study, a specific quantitative PCR system for the detection and identification of Prototheca zopfii genotypes was developed using a TaqMan } MGB probe and ResoLight dye. The P. zopfii-specific primers 18PZF1 and 18PZR1 were generated on the basis of the alignment of the small subunit ribosomal DNA domain base sequences of the genera Chlorella and Prototheca obtained from DDBJ/EMBL/GenBank, and the TaqMan } MGB probe PZP1 was designed corresponding to this amplification region. Analysis of the melting curves of the amplicons using ResoLight dye was able to differentiate between P. zopfii genotypes 1 and 2. The specificity of this detection system was examined using strains from a culture collection (28 strains) and clinical isolates (140 strains). The TaqMan } MGB probe amplicon was detected only in reference strains of P. zopfii (n ＝ 12) and clinical isolates (n ＝ 135). Ninety-two clinical specimens from cows with mastitis (36 samples) and healthy controls (56 samples) were also tested. All isolates from milk samples (n ＝ 92) and clinical isolates (n ＝ 135) were identified as P. zopfii genotype 2.

Nippon Ishinkin Gakkai Zasshi, 2006

The conidia of filamentous fungi can be easily blown into the air and tend to be contaminants in ... more The conidia of filamentous fungi can be easily blown into the air and tend to be contaminants in the laboratory environment. We developed a new safety culture tube for fungi to prevent biohazards and a procedure for collecting conidia for passage or fixing strains was proposed.

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy, 2014

This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed ... more This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed patient. The patient was a 62-year-old housewife who presented general malaise in April 2011. Hairy cell leukemia was highly suspected. Chemotherapy was started because the patient developed severe pancytopenia in October 2011. Itraconazole capsules (100 mg/day) and trimethoprim (320 mg/day) plus sulfamethoxazole (1600 mg/day) combinations were orally administered for prophylaxis of fungal infections. Of BacT/ALERT 3D FA aerobic culture bottles and FN anaerobic culture bottles, only FA aerobic blood culture bottles produced positive reactions when the patient developed fever in January 2012. Gram-staining of blood culture bottles revealed Gram-negative elliptical sporangia. Culturing on Sabouraud dextrose agar produced smooth and creamy white, yeast-like colonies. Partial DNA sequences of the nuclear 18S rDNA and 28S rDNA D1/D2 domains of the isolated strain were identical to those of P....

Nippon Ishinkin Gakkai Zasshi, 2008

Veterinary Microbiology, 2008

This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine masti... more This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine mastitis and the cow-barn surroundings by molecular characterization to clarify routes of infection for bovine protothecal mastitis. We performed isolation of Prototheca from cow-barn surroundings (drinking water, sewage and feces) and milk samples from cases of bovine mastitis. Genotypes of the 32 isolates of P. zopfii from cow-barn surroundings and 67 isolates from mastitis were analyzed by genotype-specific PCR assays and restriction fragment length polymorphism (RFLP) assays. All mastitis isolates were identified as P. zopfii genotype 2. Conversely, 29 isolates from cow-barn surroundings were identified as P. zopfii genotypes 1 and 3 isolates as genotype 2, respectively. Given these results, both genotypes of P. zopfii could exist in cow-barn surroundings, but no sites were identified as frequent sources of P. zopfii genotype 2. P. zopfii isolates should thus be further explored with regard to genotype to clarify the reservoir of etiological agents in bovine Prototheca mastitis.

Food Control, May 1, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Dairy Science, Aug 1, 2012

Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion ... more Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion of thin watery milk with white flakes. Prototheca zopfii has been biochemically and serologically divided into at least 2 genotypes, P. zopfii genotype 1 and P. zopfii genotype 2. The latter is known to be the main causative agent of bovine protothecal mastitis. Prototheca zopfii was later reclassified into 5 varieties: var. zopfii (genotypes 1 and 2), var. 1 (formerly Prototheca blaschkeae), var. 3 (formerly P. moriformis), and var. portoricensis. In this study, the 18S ribosomal DNA sequences of diverse clinical specimens from different areas in Japan were studied to clarify the pathogenicity of P. zopfii var. zopfii. The phylogenetic tree revealed that all genotype 2 isolates were grouped in a cluster of P. zopfii var. zopfii SAG 2021 T (type strain genotype 2), and were independent from the cluster of the genotype 1 isolates. Thus, all isolates from bovine mastitis in Japan were identified as P. zopfii genotype 2. Therefore, P. zopfii var. zopfii genotype 2 is associated with bovine mastitis.

Journal of Dermatological Science, Apr 1, 2009

that the Tunisian families are likely linked to the previously identified critical 15q22–15q24 in... more that the Tunisian families are likely linked to the previously identified critical 15q22–15q24 interval. For families PPK3 and PPK4, no other cases could be investigated. Nevertheless, it is noteworthy that the two patients belonging to these families shared a common haplotype between markers D15S534 and D15S650. Parametric multipoint linkage analysis gave the maximum cumulative lod score value of 5.33 for marker D15S650. These results support genetic linkage of the PPK-families to the tested critical interval on 15q22–15q24. It is noteworthy that in family PPK2, individuals IV-1 and IV-2 born to a consanguineous marriage were homozygous for the interval between microsatellite markers D15S213 and D15S988; this segment is likely inherited from a common ancestor. As their mother III-2 was healthy, this suggests that the disease locus should be distal to marker D15S988. In the present study, we provide confirmatory evidence for the location of the punctate PPK in 15q22–15q24 although the precise gene interval should be reconsidered when compared to the study of Gao et al. that suggested that the disease is proximal to D15S988, based on recombinant healthy individuals [5]. To our knowledge, this is the first report of Buschke–Fischer– Brauer’s disease in North African families.

Nippon Ishinkin Gakkai Zasshi, 2008

Kansenshōgaku zasshi, 2009

Journal of Veterinary Medical Science, 2011

Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cur... more Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cure. Therefore, prevention is the best approach and this is best achieved through the use of effective disinfectants. The aim of this study was to evaluate the in vitro algaecide efficacy of conventional disinfectants against strains of P. zopfii genotype 1 and 2. The minimal algaecide concentration (MAC) of alkyldiaminoethylglycine hydrochloride, chlorhexidine, dioxide chlorine, povidone iodine and sodium hypochlorous acid against 10 isolates and the type strain (SAG2063 T) of P. zopfii genotype 1 as well as 10 isolates and the type strain (SAG2021 T) of P. zopfii genotype 2 were examined using the micro dilution method. This in vitro study indicated that alkyldiaminoethylglycine hydrochloride, chlorhexidine, povidone iodine and sodium hypochlorous acid, but not dioxide chlorine, are effective against both genotypes of P. zopfii.

Journal of Veterinary Medical Science, 2011

Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cur... more Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cure. Therefore, prevention is the best approach and this is best achieved through the use of effective disinfectants. The aim of this study was to evaluate the in vitro algaecide efficacy of conventional disinfectants against strains of P. zopfii genotype 1 and 2. The minimal algaecide concentration (MAC) of alkyldiaminoethylglycine hydrochloride, chlorhexidine, dioxide chlorine, povidone iodine and sodium hypochlorous acid against 10 isolates and the type strain (SAG2063 T) of P. zopfii genotype 1 as well as 10 isolates and the type strain (SAG2021 T) of P. zopfii genotype 2 were examined using the micro dilution method. This in vitro study indicated that alkyldiaminoethylglycine hydrochloride, chlorhexidine, povidone iodine and sodium hypochlorous acid, but not dioxide chlorine, are effective against both genotypes of P. zopfii.

Journal of Infection and Chemotherapy, Oct 1, 2014

This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed ... more This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed patient. The patient was a 62-year-old housewife who presented general malaise in April 2011. Hairy cell leukemia was highly suspected. Chemotherapy was started because the patient developed severe pancytopenia in October 2011. Itraconazole capsules (100 mg/day) and trimethoprim (320 mg/day) plus sulfamethoxazole (1600 mg/day) combinations were orally administered for prophylaxis of fungal infections. Of BacT/ALERT 3D FA aerobic culture bottles and FN anaerobic culture bottles, only FA aerobic blood culture bottles produced positive reactions when the patient developed fever in January 2012. Gramstaining of blood culture bottles revealed Gram-negative elliptical sporangia. Culturing on Sabouraud dextrose agar produced smooth and creamy white, yeast-like colonies. Partial DNA sequences of the nuclear 18S rDNA and 28S rDNA D1/D2 domains of the isolated strain were identical to those of P. zopfii genotype 2. The MICs and minimal lethal concentrations of antifungals revealed that it was susceptible to amphotericin B and itraconazole. The patient died, at which time plasma (1 / 3)-b-D-glucan was positive (131 pg/mL).

Medical Mycology, Feb 1, 2011

(GM), kanamycin (KM) and itraconazole (ITZ) [6-10]. However, in vitro susceptibility tests on the... more (GM), kanamycin (KM) and itraconazole (ITZ) [6-10]. However, in vitro susceptibility tests on the two P. zopfi i genotypes have not been well investigated. This is the fi rst study to assess the susceptibility of genotype 2 isolates from bovine mastitis and genotype 1 strains recovered from cow-barn surroundings. Materials and methods Strains The type P. zopfi i strain of genotype 1 (SAG2063 T) and genotype 2 (SAG2021 T) were used for susceptibility tests. In addition, 10 isolates of P. zopfi i genotype 2 were recovered from 10 cases of bovine protothecal mastitis in Japan. Ten isolates of P. zopfi i genotype 1 were obtained from Japanese farm stock [3]. These isolates were previously defi ned by an 18S rDNA-based genotype-specifi c PCR assay [3-5] (Table 1).

Journal of Medical Microbiology, 2008

Loop-mediated isothermal amplification (LAMP) is a novel, rapid nucleic acid amplification method... more Loop-mediated isothermal amplification (LAMP) is a novel, rapid nucleic acid amplification method with high specificity and sensitivity under isothermal conditions. In this study a LAMP assay for diagnosing Pneumocystis pneumonia (PCP) was developed. Oligonucleotide primers specific for Pneumocystis species were designed corresponding to 18S rRNA gene sequences. The assay, performed for 30 min at 61 6C, was capable of detecting 50 copies per tube (2¾10 3 copies ml "1) in 30 min and did not show cross-reactivity to other species of fungi, including the genera Candida, Aspergillus and Cryptococcus. A total of 21 of 24 clinical specimens (sputum and bronchoalveolar lavage fluid) from patients with suspected PCP tested positive using the LAMP assay by real-time fluorescence detection. The results of the LAMP reaction were also observed by real-time turbidity detection and end-point visual turbidity or fluorescence detection. With real-time fluorescence detection, melting curves of the products were effective at distinguishing specific amplification from non-specific amplification or self-amplification. Visual detection was also possible as a rapid and easy assay using only a heat block and a black light. Recently, a new specific DNA amplification technique called loop-mediated isothermal amplification (LAMP) was developed (Nagamine et al., 2002; Notomi et al., 2000), and has already been applied to the detection of pathogenic viruses (Poon et al., 2005), bacteria (Iwamoto et al., 2003), parasites (Poon et al., 2006) and fungi (Endo et al., 2004). LAMP, which does not involve the use of PCR, allows the rapid amplification of DNA with high specificity under isothermal conditions using DNA polymerase with

Kansenshōgaku zasshi, 2004

Japanese Journal of Infectious Diseases, 2013

In this study, a specific quantitative PCR system for the detection and identification of Prototh... more In this study, a specific quantitative PCR system for the detection and identification of Prototheca zopfii genotypes was developed using a TaqMan } MGB probe and ResoLight dye. The P. zopfii-specific primers 18PZF1 and 18PZR1 were generated on the basis of the alignment of the small subunit ribosomal DNA domain base sequences of the genera Chlorella and Prototheca obtained from DDBJ/EMBL/GenBank, and the TaqMan } MGB probe PZP1 was designed corresponding to this amplification region. Analysis of the melting curves of the amplicons using ResoLight dye was able to differentiate between P. zopfii genotypes 1 and 2. The specificity of this detection system was examined using strains from a culture collection (28 strains) and clinical isolates (140 strains). The TaqMan } MGB probe amplicon was detected only in reference strains of P. zopfii (n ＝ 12) and clinical isolates (n ＝ 135). Ninety-two clinical specimens from cows with mastitis (36 samples) and healthy controls (56 samples) were also tested. All isolates from milk samples (n ＝ 92) and clinical isolates (n ＝ 135) were identified as P. zopfii genotype 2.

Food Control

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Applied Microbiology, 2021

Aims The aim of the study was to develop a microarray-based method for the detection of antibioti... more Aims The aim of the study was to develop a microarray-based method for the detection of antibiotic-resistant Campylobacter in broiler farms to decrease the risk of contamination of chicken meat. Methods and Results A combination of DNA microarray and primer extension for rapid and simultaneous detection of fluoroquinolone- and macrolide-resistant Campylobacter jejuni/Campylobacter coli, termed Campylobacter Express Resistance Array (CAMERA), was used to analyse chicken caecal droppings. CAMERA assays could detect at least 105 colony forming units of C. jejuni/C. coli g−1 of chicken caecal contents spiked with C. jejuni/C. coli. To compare the CAMERA method and direct culturing method for screening antibiotic-resistant C. jejuni/C. coli in poultry farms, chicken caecal droppings obtained from 42 poultry houses were analysed using both methods. In total, 95.2% of the results (40/42 poultry houses) obtained using the CAMERA and culturing method were identical. In the remaining two poul...

Kansenshogaku Zasshi, 2009

Japanese Journal of Infectious Diseases, 2013

In this study, a specific quantitative PCR system for the detection and identification of Prototh... more In this study, a specific quantitative PCR system for the detection and identification of Prototheca zopfii genotypes was developed using a TaqMan } MGB probe and ResoLight dye. The P. zopfii-specific primers 18PZF1 and 18PZR1 were generated on the basis of the alignment of the small subunit ribosomal DNA domain base sequences of the genera Chlorella and Prototheca obtained from DDBJ/EMBL/GenBank, and the TaqMan } MGB probe PZP1 was designed corresponding to this amplification region. Analysis of the melting curves of the amplicons using ResoLight dye was able to differentiate between P. zopfii genotypes 1 and 2. The specificity of this detection system was examined using strains from a culture collection (28 strains) and clinical isolates (140 strains). The TaqMan } MGB probe amplicon was detected only in reference strains of P. zopfii (n ＝ 12) and clinical isolates (n ＝ 135). Ninety-two clinical specimens from cows with mastitis (36 samples) and healthy controls (56 samples) were also tested. All isolates from milk samples (n ＝ 92) and clinical isolates (n ＝ 135) were identified as P. zopfii genotype 2.

Nippon Ishinkin Gakkai Zasshi, 2006

The conidia of filamentous fungi can be easily blown into the air and tend to be contaminants in ... more The conidia of filamentous fungi can be easily blown into the air and tend to be contaminants in the laboratory environment. We developed a new safety culture tube for fungi to prevent biohazards and a procedure for collecting conidia for passage or fixing strains was proposed.

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy, 2014

This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed ... more This report describes a fatal case Prototheca zopfii genotype 2 infection in an immunosuppressed patient. The patient was a 62-year-old housewife who presented general malaise in April 2011. Hairy cell leukemia was highly suspected. Chemotherapy was started because the patient developed severe pancytopenia in October 2011. Itraconazole capsules (100 mg/day) and trimethoprim (320 mg/day) plus sulfamethoxazole (1600 mg/day) combinations were orally administered for prophylaxis of fungal infections. Of BacT/ALERT 3D FA aerobic culture bottles and FN anaerobic culture bottles, only FA aerobic blood culture bottles produced positive reactions when the patient developed fever in January 2012. Gram-staining of blood culture bottles revealed Gram-negative elliptical sporangia. Culturing on Sabouraud dextrose agar produced smooth and creamy white, yeast-like colonies. Partial DNA sequences of the nuclear 18S rDNA and 28S rDNA D1/D2 domains of the isolated strain were identical to those of P....

Nippon Ishinkin Gakkai Zasshi, 2008

Veterinary Microbiology, 2008

This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine masti... more This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine mastitis and the cow-barn surroundings by molecular characterization to clarify routes of infection for bovine protothecal mastitis. We performed isolation of Prototheca from cow-barn surroundings (drinking water, sewage and feces) and milk samples from cases of bovine mastitis. Genotypes of the 32 isolates of P. zopfii from cow-barn surroundings and 67 isolates from mastitis were analyzed by genotype-specific PCR assays and restriction fragment length polymorphism (RFLP) assays. All mastitis isolates were identified as P. zopfii genotype 2. Conversely, 29 isolates from cow-barn surroundings were identified as P. zopfii genotypes 1 and 3 isolates as genotype 2, respectively. Given these results, both genotypes of P. zopfii could exist in cow-barn surroundings, but no sites were identified as frequent sources of P. zopfii genotype 2. P. zopfii isolates should thus be further explored with regard to genotype to clarify the reservoir of etiological agents in bovine Prototheca mastitis.