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The emergence and spread of nonencapsulated Streptococcus pneumoniae (NESp) is a public health concern in the post-pneumococcal conjugate vaccine era. We analyzed the prevalence, molecular characteristics, and antimicrobial resistance of NESp responsible for non-invasive infections in northern Japan. Among 4463 S. pneumoniae isolates collected from non-invasive infection cases during four study periods between January 2011 and January 2019, NESp isolates were identified using molecular and phenotypical methods. NESp isolates were analyzed for antimicrobial susceptibility, genotype, and virulence-associated genes. A total of 71 NESp isolates were identified (1.6% of all the clinical isolates) and assigned to the null capsule clade (NCC)1 (pspK+) (94.4%) or NCC2 (aliC+/aliD+) (5.6%). Five dominant sequence types (STs) were ST7502 (23.9%), ST4845 (19.7%), ST16214 (11.3%), ST11379 (9.9%), and ST7786 (7.0%). These dominant STs and all seven novel STs were related to the sporadic NESp lineage ST1106 or PMEN clone Denmark14-ST230. High non-susceptibility rates of NESp were observed for trimethoprim-sulfamethoxazole, erythromycin, and tetracycline (>92.9%), and multidrug resistance was observed in 88.7% of the NESp isolates, including all the ST7502, ST4845, and ST11379 isolates. The present study revealed that the dominant clonal groups of NESp were associated with a high prevalence of non-susceptibility to antimicrobials in northern Japan.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Kenji Kudo; Masahiko Ito; Ayako Sumi; Nobumichi Kobayashi. Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan. International Journal of Infectious Diseases 2021, 105, 695 -701.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Kenji Kudo, Masahiko Ito, Ayako Sumi, Nobumichi Kobayashi. Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan. International Journal of Infectious Diseases. 2021; 105 ():695-701.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Kenji Kudo; Masahiko Ito; Ayako Sumi; Nobumichi Kobayashi. 2021. "Clonal lineages and antimicrobial resistance of nonencapsulated Streptococcus pneumoniae in the post-pneumococcal conjugate vaccine era in Japan." International Journal of Infectious Diseases 105, no. : 695-701.
Staphylococcus argenteus, a novel staphylococcal species independent of S. aureus, causes a wide spectrum of infectious diseases. As detection of this species from humans and animals has been increasingly reported worldwide, its growing virulence and drug resistance via external genetic determinants has become concerning. In this study, the prevalence and genetic characteristics of virulence factors and drug resistance determinants were investigated for 82 S. argenteus clinical isolates in Hokkaido, Japan, for a one-year period starting in August 2019. These S. argenteus isolates corresponded to 0.66% of the total number of S. aureus isolates collected in the same period. The most prevalent genotype was sequence type (ST) 2250 and staphylocoagulase (coa) genotype XId (45.1%, n = 37), followed by ST1223-coa XV (30.5%, n = 25) and ST2198-coa XIV (24.4%, n = 20). Panton-Valentine leukocidin genes (lukS-PV-lukF-PV) were identified in a single ST2250 isolate. Only ST1223 isolates had the enterotoxin gene cluster (egc-2), seb, and selw (detection rate; 100%, 60%, and 84%, respectively), while sec, sey, sel26-sel27, tst-1 were only detected in ST2250 isolates (detection rate; 10.8%, 100%, 67.6%, and 10.8%, respectively). ST2198 isolates harbored selx at a significantly higher rate (60%) than isolates of other STs. Although most of S. argenteus isolates were susceptible to antimicrobials examined, ST2198 showed higher resistance rates to penicillin, macrolides, and aminoglycosides than other STs, and it harbored various resistance genes such as blaZ, erm(C), msr(A), lnuA, and aac(6′)-Ie-aph(2″)-Ia. Only one ST2250 isolate possessed SCCmec-IVc, showing resistance to oxacillin. blaZ was the most prevalent determinant of resistance in the three STs and belonged to two plasmid groups and a chromosomal group, suggesting its diverse origin. lnu(A) in ST2198 isolates was assigned to a major cluster with various staphylococcal species. The present study indicates that the prevalence of virulence factors and drug resistance profile/determinants differ depending on the lineage (ST) of S. argenteus.
Meiji Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Mina Hirose; Miyo Ike; Masahiko Ito; Nobumichi Kobayashi. Distribution of Virulence Factors and Resistance Determinants in Three Genotypes of Staphylococcus argenteus Clinical Isolates in Japan. Pathogens 2021, 10, 163 .
AMA StyleMeiji Aung, Noriko Urushibara, Mitsuyo Kawaguchiya, Mina Hirose, Miyo Ike, Masahiko Ito, Nobumichi Kobayashi. Distribution of Virulence Factors and Resistance Determinants in Three Genotypes of Staphylococcus argenteus Clinical Isolates in Japan. Pathogens. 2021; 10 (2):163.
Chicago/Turabian StyleMeiji Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Mina Hirose; Miyo Ike; Masahiko Ito; Nobumichi Kobayashi. 2021. "Distribution of Virulence Factors and Resistance Determinants in Three Genotypes of Staphylococcus argenteus Clinical Isolates in Japan." Pathogens 10, no. 2: 163.
Enterococcus faecalis is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for E. faecalis clinical isolates in north-central Bangladesh. Among a total of 210 E. faecalis isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.2, 45.7, and 11.4%, respectively, while no isolates were resistant to ampicillin, vancomycin and teicoplanin. The most prevalent resistance gene was erm(B) (97%), and any of the four genes encoding aminoglycoside modifying enzyme (AME) were detected in 99 isolates (47%). The AME gene aac(6′)-Ie-aph(2”)-Ia was detected in 46 isolates (21.9%) and was diverse in terms of IS256-flanking patterns, which were associated with resistance level to gentamicin. Tetracycline resistance was ascribable to tet(M) (61%) and tet(L) (38%), and mutations in the quinolone resistance-determining region of both GyrA and ParC were identified in 44% of isolates. Five isolates (2.4%) exhibited non-susceptibility to linezolide (MIC, 4 μg/mL), and harbored the oxazolidinone resistance gene optrA, which was located in a novel genetic cluster containing the phenicol exporter gene fexA. The optrA-positive isolates belonged to ST59, ST902, and ST917 (CC59), while common lineages of other multiple drug-resistant isolates were ST6, ST28, CC16, and CC116. The present study first revealed the prevalence of drug resistance determinants of E. faecalis and their genetic profiles in Bangladesh.
Sangjukta Roy; Meiji Soe Aung; Shyamal Kumar Paul; Salma Ahmed; Nazia Haque; Emily Rahman Khan; Tridip Kanti Barman; Arup Islam; Sahida Abedin; Chand Sultana; Anindita Paul; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages. Microorganisms 2020, 8, 1240 .
AMA StyleSangjukta Roy, Meiji Soe Aung, Shyamal Kumar Paul, Salma Ahmed, Nazia Haque, Emily Rahman Khan, Tridip Kanti Barman, Arup Islam, Sahida Abedin, Chand Sultana, Anindita Paul, Muhammad Akram Hossain, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Nobumichi Kobayashi. Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages. Microorganisms. 2020; 8 (8):1240.
Chicago/Turabian StyleSangjukta Roy; Meiji Soe Aung; Shyamal Kumar Paul; Salma Ahmed; Nazia Haque; Emily Rahman Khan; Tridip Kanti Barman; Arup Islam; Sahida Abedin; Chand Sultana; Anindita Paul; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. 2020. "Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages." Microorganisms 8, no. 8: 1240.
Staphylococcal enterotoxins (SEs) are virulence factors of Staphylococcus aureus associated with various toxic diseases due to their emetic and superantigenic activities. Although at least 27 SE(-like) genes have been identified in S. aureus to date, the newly identified SE(-like) genes have not yet been well characterized by their epidemiological features. In this study, the prevalence and genetic diversity of SE gene sey and SE-like genes selw, selx, selz, sel26, and sel27 were investigated for 624 clinical isolates of community-acquired methicillin-resistant S. aureus (CA-MRSA). The most prevalent SE(-like) gene was selw (92.9%), followed by selx (85.6%), sey (35.4%) and selz (5.6%), while sel26 and sel27 were not detected. Phylogenetically, sey, selw, selx, and selz were discriminated into 7, 10, 16, and 9 subtypes (groups), respectively. Among these subtypes, sey was the most conserved and showed the highest sequence identity (>98.8%), followed by selz and selx. The SE-like gene selw was the most divergent, and four out of ten genetic groups contained pseudogenes that may encode truncated product. Individual subtypes of SE(-like) genes were generally found in isolates with specific genotypes/lineages of S. aureus. This study revealed the putative ubiquity of selw and selx and the prevalence of sey and selz in some specific lineages (e.g., ST121) in CA-MRSA, suggesting a potential role of these newly described SEs(-like) in pathogenicity.
Meiji Soe Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi. Prevalence and Genetic Diversity of Staphylococcal Enterotoxin (-Like) Genes sey, selw, selx, selz, sel26 and sel27 in Community-Acquired Methicillin-Resistant Staphylococcus aureus. Toxins 2020, 12, 347 .
AMA StyleMeiji Soe Aung, Noriko Urushibara, Mitsuyo Kawaguchiya, Masahiko Ito, Satoshi Habadera, Nobumichi Kobayashi. Prevalence and Genetic Diversity of Staphylococcal Enterotoxin (-Like) Genes sey, selw, selx, selz, sel26 and sel27 in Community-Acquired Methicillin-Resistant Staphylococcus aureus. Toxins. 2020; 12 (5):347.
Chicago/Turabian StyleMeiji Soe Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi. 2020. "Prevalence and Genetic Diversity of Staphylococcal Enterotoxin (-Like) Genes sey, selw, selx, selz, sel26 and sel27 in Community-Acquired Methicillin-Resistant Staphylococcus aureus." Toxins 12, no. 5: 347.
Multidrug resistance (MDR) in non-vaccine serotypes (NVTs)-Streptococcus pneumoniae is a global public health concern after the widespread use of pneumococcal conjugate vaccines (PCVs). The present study aimed to analyze the prevalence of serotypes and antimicrobial susceptibilities of non-invasive/colonization isolates of S. pneumoniae eight years after the introduction of PCV in Japan. A total of 545 non-invasive pneumococcal isolates (460 children, 85 adults) obtained from July 2018 to January 2019 were studied. All isolates were tested for susceptibility to ten antimicrobials and were characterized for serotypes, penicillin binding protein (PBP) genotypes, and macrolide resistance genes. Among children, 95.0% of isolates belonged to non-13-valent pneumococcal conjugate vaccine (PCV13) serotypes (NVTs), with 15A (15.0%) being dominant, followed by 35B (12.2%), 23A (11.1%), 15B (9.8%), and 15C (9.6%). In contrast, serotype 3 (18.8%) was the most prevalent in adults, while 15A, 10A, and 23A were also common. Serotypes covered by PCV13 and 23-valent pneumococcal polysaccharide vaccine (PPSV23) in all the adult isolates were 25.9% and 48.2%, respectively. High resistance rates were observed against erythromycin, tetracycline, and clindamycin (≥62.4% children, ≥58.8% adults). Penicillin-resistant and penicillin-intermediate isolates represented 2.2% and 33.8% of all isolates, respectively. Most isolates of the three dominant NVTs 15A, 35B, and 23A were non-susceptible to penicillin. Overall, multiple drug resistance (MDR) was detected in 69.0% of all isolates, including dominant NVTs 15A, 35B, 23A, 15B, and 15C. Among all the isolates, 81.8% harbored at least one altered PBP genes, and erm(B), mef(A/E) and both these genes were found in 68.2%, 23.3%, and 6.8%, respectively. High prevalence (>90%) of erm(B) was observed in serogroup 15, and serotypes 23A, 33F, and 12F. The present study revealed the high prevalence of NVTs 15 and 23A, and 35B showing MDR, suggesting their spread after introduction of routine PCV immunization.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masahiko Ito; Ayana Takahashi; Satoshi Habadera; Nobumichi Kobayashi. High prevalence of antimicrobial resistance in non-vaccine serotypes of non-invasive/colonization isolates of Streptococcus pneumoniae: A cross-sectional study eight years after the licensure of conjugate vaccine in Japan. Journal of Infection and Public Health 2020, 13, 1094 -1100.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Masahiko Ito, Ayana Takahashi, Satoshi Habadera, Nobumichi Kobayashi. High prevalence of antimicrobial resistance in non-vaccine serotypes of non-invasive/colonization isolates of Streptococcus pneumoniae: A cross-sectional study eight years after the licensure of conjugate vaccine in Japan. Journal of Infection and Public Health. 2020; 13 (8):1094-1100.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masahiko Ito; Ayana Takahashi; Satoshi Habadera; Nobumichi Kobayashi. 2020. "High prevalence of antimicrobial resistance in non-vaccine serotypes of non-invasive/colonization isolates of Streptococcus pneumoniae: A cross-sectional study eight years after the licensure of conjugate vaccine in Japan." Journal of Infection and Public Health 13, no. 8: 1094-1100.
Increase of extraintestinal pathogenic Escherichia coli (ExPEC) showing resistance to beta-lactams is a major public health concern. This study was conducted as a first molecular epidemiological study on ExPEC in Cuba, regarding prevalence of extended-spectrum beta-lactamases (ESBLs) and carbapenemase genes. A total of 306 ExPEC isolates collected in medical institutions in 16 regions in Cuba (2014–2018) were analyzed for their genotypes and presence of genes encoding ESBL, carbapenemase, plasmid-mediated quinolone resistance (PMQR) determinants by PCR and sequencing. The most common phylogenetic group of ExPEC was B2 (49%), followed by D (23%), A (21%), and B1 (7%). Among ESBL genes detected, blaCTX-M was the most common and detected in 61% of ExPEC, with blaCTX-M-15 being dominant and distributed to all the phylogenetic groups. NDM-1 type carbapenemase gene was identified in two isolates of phylogenetic group B1-ST448. Phylogenetic group B2 ExPEC belonged to mostly ST131 (or its single-locus variant) with O25b allele, harboring blaCTX-M-27, and included an isolate of emerging type ST1193. aac (6’)-Ib-cr was the most prevalent PMQR gene (40.5%), being present in 54.5% of CTX-M-positive isolates. These results indicated high prevalence of CTX-M genes and the emergence of NDM-1 gene among recent ExPEC in Cuba, depicting an alarming situation.
Dianelys Quiñones; Meiji Soe Aung; Yenisel Carmona; María Karla González; Niurka Pereda; Mercedes Hidalgo; Mayrelis Rivero; Arnaldo Zayas; Rosa Del Campo; Noriko Urushibara; Nobumichi Kobayashi; Arnaldo Zallas. High Prevalence of CTX-M Type Extended-Spectrum Beta-Lactamase Genes and Detection of NDM-1 Carbapenemase Gene in Extraintestinal Pathogenic Escherichia coli in Cuba. Pathogens 2020, 9, 65 .
AMA StyleDianelys Quiñones, Meiji Soe Aung, Yenisel Carmona, María Karla González, Niurka Pereda, Mercedes Hidalgo, Mayrelis Rivero, Arnaldo Zayas, Rosa Del Campo, Noriko Urushibara, Nobumichi Kobayashi, Arnaldo Zallas. High Prevalence of CTX-M Type Extended-Spectrum Beta-Lactamase Genes and Detection of NDM-1 Carbapenemase Gene in Extraintestinal Pathogenic Escherichia coli in Cuba. Pathogens. 2020; 9 (1):65.
Chicago/Turabian StyleDianelys Quiñones; Meiji Soe Aung; Yenisel Carmona; María Karla González; Niurka Pereda; Mercedes Hidalgo; Mayrelis Rivero; Arnaldo Zayas; Rosa Del Campo; Noriko Urushibara; Nobumichi Kobayashi; Arnaldo Zallas. 2020. "High Prevalence of CTX-M Type Extended-Spectrum Beta-Lactamase Genes and Detection of NDM-1 Carbapenemase Gene in Extraintestinal Pathogenic Escherichia coli in Cuba." Pathogens 9, no. 1: 65.
Staphylococcus argenteus, a novel emerging species within Staphylococcus aureus complex (SAC), has been increasingly reported worldwide. In this study, prevalence of S. argenteus among human clinical isolates, and their clonal diversity and genetic characteristics of virulence factors were investigated in Hokkaido, the northern main island of Japan. During a four-month period starting from March 2019, twenty-four S. argenteus and 4330 S. aureus isolates were recovered from clinical specimens (the ratio of S. argenteus to S. aureus :0.0055). Half of S. argenteus isolates (n = 12) belonged to MLST sequence type (ST) 2250 and its single-locus variant, with staphylocoagulase genotype (coa-) XId, while the remaining isolates were assigned to ST2198/coa-XIV (n = 6), and ST1223 with a novel coa-XV identified in this study (n = 6). All the isolates were mecA-negative, and susceptible to all the antimicrobials tested, except for an ST2198 isolate with blaZ and an ST2250 isolate with tet(L) showing resistance to ampicillin and tetracyclines, respectively. Common virulence factors in the S. argenteus isolates were staphylococcal enterotoxin (-like) genes sey, selz, sel26, and sel27 in ST2250, selx in ST2198, and enterotoxin gene cluster (egc-1: seg-sei-sem-sen-seo) in ST1223 isolates, in addition to hemolysin genes (hla, hlb, and hld) distributed universally. Elastin binding protein gene (ebpS) and MSCRAMM family adhesin SdrE gene (sdrE) detected in all the isolates showed high sequence identity among them (> 97%), while relatively lower identity to those of S. aureus (78–92%). Phylogenetically, ebpS, sdrE, selx, sey, selw, sel26, and sel27 of S. argenteus formed clusters distinct from those of S. aureus, unlike sec, selz, tst-1, and staphylokinase gene (sak). The present study revealed the prevalence of S. argenteus among clinical isolates, and presence of three distinct S. argenteus clones (ST2250; ST2198 and ST1223) harboring different virulence factors in northern Japan. ST2198 S. argenteus, a minor clone (strain BN75-like) that had been rarely reported, was first identified in Japan as human isolates.
Meiji Soe Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Seika Takahashi; Miyo Ike; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi; Aung; Sumi; Ike; Ito. Molecular Epidemiological Characterization of Staphylococcus argenteus Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV. Microorganisms 2019, 7, 389 .
AMA StyleMeiji Soe Aung, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Seika Takahashi, Miyo Ike, Masahiko Ito, Satoshi Habadera, Nobumichi Kobayashi, Aung, Sumi, Ike, Ito. Molecular Epidemiological Characterization of Staphylococcus argenteus Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV. Microorganisms. 2019; 7 (10):389.
Chicago/Turabian StyleMeiji Soe Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Seika Takahashi; Miyo Ike; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi; Aung; Sumi; Ike; Ito. 2019. "Molecular Epidemiological Characterization of Staphylococcus argenteus Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV." Microorganisms 7, no. 10: 389.
Pneumococcal proteins unrelated to serotypes are considered to be candidates of antigens in next-generation vaccines. In the present study, the prevalence of vaccine candidate protein genes, along with serotypes and antimicrobial resistance determinants, was investigated in a total of 57 isolates obtained from a tertiary care hospital in Japan. All of the pediatric isolates and 76.6% of the adult isolates did not belong to PCV13 (a 13-valent pneumococcal conjugate vaccine) serotypes, and 70.2% of all isolates showed multidrug resistance. All of the isolates had ply, pavA, nanA, and nanB, and high prevalence was noted for the pspA and pspC genes (96.5% and 78.9%, respectively). Detection rates for the pneumococcal histidine triad protein (Pht) genes phtA, phtB, phtD, and phtE were 49.1%, 26.3%, 61.4%, and 100%, respectively. Two fusion-type genes, phtA/B and phtA/D, were identified, with a prevalence of 36.9% and 14.0%, respectively. These fusion types showed 78.1–90.0% nucleotide sequence identity with phtA, phtB, and phtD. The most prevalent pht profile was phtA + phtD + phtE (26.3%), followed by phtA/B + phtE (19.3%) and phtA/B + phtD + phtE (17.5%), while pht profiles including phtD and/or phtA/phtD were found in 71.9% of isolates. The present study revealed the presence of two fusion types of Pht and their unexpectedly high prevalence. These fusion types, as well as PhtA and PhtB, contained sequences similar to the B cell epitopes that have been previously reported for PhtD.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi; Aung. Prevalence of Various Vaccine Candidate Proteins in Clinical Isolates of Streptococcus pneumoniae: Characterization of the Novel Pht Fusion Proteins PhtA/B and PhtA/D. Pathogens 2019, 8, 162 .
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Masaaki Shinagawa, Satoshi Takahashi, Nobumichi Kobayashi, Aung. Prevalence of Various Vaccine Candidate Proteins in Clinical Isolates of Streptococcus pneumoniae: Characterization of the Novel Pht Fusion Proteins PhtA/B and PhtA/D. Pathogens. 2019; 8 (4):162.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi; Aung. 2019. "Prevalence of Various Vaccine Candidate Proteins in Clinical Isolates of Streptococcus pneumoniae: Characterization of the Novel Pht Fusion Proteins PhtA/B and PhtA/D." Pathogens 8, no. 4: 162.
Clostridium perfringens (C. perfringens) is responsible for food-borne gastroenteritis and other infectious diseases, and toxins produced by this bacterium play a key role in pathogenesis. Although various toxins have been described for C. perfringens isolates from humans and animals, prevalence of individual toxins among clinical isolates has not yet been well explored. In the present study, a total of 798 C. perfringens clinical isolates were investigated for prevalence of eight toxin genes and their genetic diversity by PCR, nucleotide sequencing, and phylogenetic analysis. Besides the alpha-toxin gene (plc) present in all the isolates, the most common toxin gene was cpe (enterotoxin) (34.2%), followed by cpb2 (beta2 toxin) (1.4%), netB (NetB) (0.3%), and bec/cpile (binary enterotoxin BEC/CPILE) (0.1%), while beta-, epsilon-, and iota-toxin genes were not detected. Genetic analysis of toxin genes indicated a high level of conservation of plc, cpe, and netB. In contrast, cpb2 was revealed to be considerably divergent, containing at least two lineages. Alpha-toxin among 46 isolates was classified into ten sequence types, among which common types were distinct from those reported for avian isolates. A single isolate with bec/cpile harbored a plc variant containing an insertion of 834-bp sequence, suggesting its putative origin from chickens.
Asami Matsuda; Meiji Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Mayumi Nakamura; Yuka Horino; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi. Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of Clostridium perfringens: Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (bec/cpile). Toxins 2019, 11, 326 .
AMA StyleAsami Matsuda, Meiji Aung, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Mayumi Nakamura, Yuka Horino, Masahiko Ito, Satoshi Habadera, Nobumichi Kobayashi. Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of Clostridium perfringens: Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (bec/cpile). Toxins. 2019; 11 (6):326.
Chicago/Turabian StyleAsami Matsuda; Meiji Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Mayumi Nakamura; Yuka Horino; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi. 2019. "Prevalence and Genetic Diversity of Toxin Genes in Clinical Isolates of Clostridium perfringens: Coexistence of Alpha-Toxin Variant and Binary Enterotoxin Genes (bec/cpile)." Toxins 11, no. 6: 326.
Genetic background and molecular characteristics of Staphylococcus aureus collected from patients with skin and soft tissue infections were studied in the North-Central region of Bangladesh from 2015 to 2016. Among 430 clinical isolates, methicillin-resistant S. aureus (MRSA) accounted for 31% having SCCmec type IV (73%) and V (14%), and belonged mostly to coagulase (coa) genotypes IIa, IIIa, IVb, and XIa, while dominant coa type in methicillin-susceptible S. aureus (MSSA) was IIIa, followed by Va, IIa, and VIa. Panton–Valentine Leukocidin genes (pvl) were detected at higher rate in MSSA (54%) than in MRSA (24%). Based on multilocus sequence typing, pvl-positive MRSA isolates were classified into clonal complex 88 (CC88) (ST88, ST2884, ST4345), CC6 (ST6, ST4350), and CC1 (ST1, ST772), while pvl-negative MRSA into CC5, CC22, CC80, CC121, and CC672. The pvl-negative ST80 MRSA isolates had SCCmec-IVa (agr-III/coa-XIc, etd/edinB-positive, fusB-negative), indicating that they belong to the novel CC80 clade related to the European community-acquired MRSA clone. Among MSSA, genotypes ST121/spa-t645/coa-Va and ST2884 (CC88)/spa-t2393/coa-IIIa were identified in both pvl-positive and negative isolates, and all the ST772 isolates harbored pvl. All the ST121 isolates had a variant of elastin-binding protein gene (ebpS-v) with internal 180-nucleotide deletion. The present study suggested that CC88 (ST88, ST2884) and ST772 are the putative dominant lineages of pvl-positive MRSA/MSSA, while novel CC80 clade is one of the main pvl-negative MRSA lineages distributed endemically in Bangladesh.
Nazia Haque; Meiji Soe Aung; Shyamal Kumar Paul; Shafikul Bari; Salma Ahmed; Santana Rani Sarkar; Sangjukta Roy; Syeda Anjuman Nasreen; Muhammad Chand Mahmud; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. Molecular Epidemiological Characterization of Methicillin-Susceptible and -ResistantStaphylococcus aureusIsolated from Skin and Soft Tissue Infections in Bangladesh. Microbial Drug Resistance 2019, 25, 241 -250.
AMA StyleNazia Haque, Meiji Soe Aung, Shyamal Kumar Paul, Shafikul Bari, Salma Ahmed, Santana Rani Sarkar, Sangjukta Roy, Syeda Anjuman Nasreen, Muhammad Chand Mahmud, Muhammad Akram Hossain, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Nobumichi Kobayashi. Molecular Epidemiological Characterization of Methicillin-Susceptible and -ResistantStaphylococcus aureusIsolated from Skin and Soft Tissue Infections in Bangladesh. Microbial Drug Resistance. 2019; 25 (2):241-250.
Chicago/Turabian StyleNazia Haque; Meiji Soe Aung; Shyamal Kumar Paul; Shafikul Bari; Salma Ahmed; Santana Rani Sarkar; Sangjukta Roy; Syeda Anjuman Nasreen; Muhammad Chand Mahmud; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. 2019. "Molecular Epidemiological Characterization of Methicillin-Susceptible and -ResistantStaphylococcus aureusIsolated from Skin and Soft Tissue Infections in Bangladesh." Microbial Drug Resistance 25, no. 2: 241-250.
Purpose. Staphylococcus argenteus is a novel emerging species of coagulase-positive staphylococcus that is genetically closely related to Staphylococcus aureus. To elucidate the molecular differences in the virulence factors (staphylocoagulase, protein A, alpha-haemolysin, enterotoxin-like toxin and staphylokinase) between these staphylococcal species, S. argenteus that had recently been isolated in Myanmar (five nasal isolates and four clinical isolates) were analysed. Methodology. The nucleotide sequences of the virulence factors were determined by PCR and direct sequencing, followed by phylogenetic analysis by mega6 and multiple alignment by clustalw using the published sequence data for S. aureus and S. argenteus. Results. Six S. argenteus isolates belonged to MLST sequence type (ST) 2250, while others belonged to ST4625, ST2198 and ST2854. The novel staphylocoagulase (coa) genotype XIV and the novel coa-XI subtype (XId) were identified in an ST2198 isolate and all other isolates, respectively. Among the S. argenteus isolates, the protein A and alpha-haemolysin genes showed high sequence identity (96–98 % and >99 %, respectively), while lower identity was observed between S. argenteus and S. aureus (88–91 % and 86 %, respectively), with both species showing phylogenetically distinct clusters. Similar findings were found for the staphylococcal enterotoxin (SE)-like toxin genes selw, selx and sely. In contrast, the staphylokinase genes were almost identical between these two species. All of the coa-XId isolates had a CRISPR/Cas locus at the site of orfX without having SCCmec, whereas an ST2198 isolate lacked this locus. Conclusion.The primary virulence factors (staphylocoagulase, protein A andalpha-haemolysin) as well as the SE-like toxins of S. argenteus were genetically discriminated from those of S. aureus, revealing the presence of the novel coa-type/subtype (coa-IXd, XIV) in S. argenteus.
Meiji Soe Aung; Thida San; Nilar San; Win Mar Oo; Phyoe May Ko; Khin Thet Thet; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. Molecular characterization of Staphylococcus argenteus in Myanmar: identification of novel genotypes/clusters in staphylocoagulase, protein A, alpha-haemolysin and other virulence factors. Journal of Medical Microbiology 2019, 68, 95 -104.
AMA StyleMeiji Soe Aung, Thida San, Nilar San, Win Mar Oo, Phyoe May Ko, Khin Thet Thet, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Nobumichi Kobayashi. Molecular characterization of Staphylococcus argenteus in Myanmar: identification of novel genotypes/clusters in staphylocoagulase, protein A, alpha-haemolysin and other virulence factors. Journal of Medical Microbiology. 2019; 68 (1):95-104.
Chicago/Turabian StyleMeiji Soe Aung; Thida San; Nilar San; Win Mar Oo; Phyoe May Ko; Khin Thet Thet; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. 2019. "Molecular characterization of Staphylococcus argenteus in Myanmar: identification of novel genotypes/clusters in staphylocoagulase, protein A, alpha-haemolysin and other virulence factors." Journal of Medical Microbiology 68, no. 1: 95-104.
Spread of Gram-negative bacteria producing extended-spectrum beta-lactamases (ESBLs) and carbapenemases constitutes a growing challenge in control of bacterial infections. In this study, prevalence and genetic characteristics of Escherichia coli and Klebsiella pneumoniae harboring ESBL and/or carbapenemase genes, with other beta-lactamase/resistance genes, were investigated for a total of 375 clinical isolates in Mymensingh located in north-central Bangladesh. The major ESBL gene was blaCTX-M-1 group, which was detected in 33.9% and 51.4% of E. coli and K. pneumoniae, respectively, with CTX-M-15 gene being dominant. SHV-type beta-lactamase genes, including newly identified alleles (SHV-201 and SHV-202) were detected at higher rate in K. pneumoniae (27%). Nine isolates of E. coli (3.9%) harbored carbapenemase genes; blaNDM-1 (phylogenetic group A-sequence type 2104 (A-ST2104), B2-ST73), blaNDM-5 (A-ST167, B2-ST38/ST2659-related STs), and blaNDM-7 (B1-ST101/ST224, D-ST6682). AmpC beta-lactamase genes (blaCMY-2, blaCMY-27, and blaCMY-42) were detected in E. coli, which mostly harbored blaCTX-M-15 and plasmid-mediated quinolone resistance (PMQR) determinants (aac6'-Ib-cr, qnrB, qnrS, qepA, and oqxAB). A new CMY allele (CMY-160) belonging to CMY-2 group was identified in phylogenetic group D E. coli. Among K. pneumoniae, carbapenemase gene was detected in three isolates (2%); blaNDM-1 in ST11 and ST1322, and blaOXA-181 in ST43 isolate. As well as higher rate of aac6'-Ib-cr in K. pneumoniae (39%), PMQR gene oqxAB was also commonly found among isolates analyzed. These findings indicated spread of blaNDM genes to diverse E. coli clones and emergence of blaOXA-181 in K. pneumoniae, with increased prevalence of ESBLs represented by CTX-M-15 in Bangladesh.
Emily Rahman Khan; Meiji Soe Aung; Shyamal Kumar Paul; Salma Ahmed; Nazia Haque; Farid Ahamed; Santana Rani Sarkar; Sangjukta Roy; Mohammad Mustafizur Rahman; Muhammad Chand Mahmud; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. Prevalence and Molecular Epidemiology of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae Harboring Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Bangladesh. Microbial Drug Resistance 2018, 24, 1568 -1579.
AMA StyleEmily Rahman Khan, Meiji Soe Aung, Shyamal Kumar Paul, Salma Ahmed, Nazia Haque, Farid Ahamed, Santana Rani Sarkar, Sangjukta Roy, Mohammad Mustafizur Rahman, Muhammad Chand Mahmud, Muhammad Akram Hossain, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Nobumichi Kobayashi. Prevalence and Molecular Epidemiology of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae Harboring Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Bangladesh. Microbial Drug Resistance. 2018; 24 (10):1568-1579.
Chicago/Turabian StyleEmily Rahman Khan; Meiji Soe Aung; Shyamal Kumar Paul; Salma Ahmed; Nazia Haque; Farid Ahamed; Santana Rani Sarkar; Sangjukta Roy; Mohammad Mustafizur Rahman; Muhammad Chand Mahmud; Muhammad Akram Hossain; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. 2018. "Prevalence and Molecular Epidemiology of Clinical Isolates of Escherichia coli and Klebsiella pneumoniae Harboring Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Bangladesh." Microbial Drug Resistance 24, no. 10: 1568-1579.
The increasing trend of Escherichia coli producing extended-spectrum beta-lactamases (ESBLs) and carbapenemases is a global public health concern. In this study, prevalence and molecular characteristics of E. coli harboring ESBL and carbapenemase genes were investigated for 426 isolates derived from various clinical specimens in a teaching hospital in Yangon, Myanmar, for the 1-year period beginning January 2016. A total of 157 isolates (36.9%) were ESBL producers and harbored CTX-M-1 group genes (146 isolates; blaCTX-M-15, blaCTX-M55) or CTX-M-9 group genes (11 isolates; blaCTX-M-14, blaCTX-M-27). Carbapenem resistance was detected in 35 isolates (8.2%), among which 26 isolates had carbapenemase genes encoding NDM-1 (2 isolates), NDM-4 (6 isolates), NDM-5 (14 isolates), NDM-7 (3 isolates), and OXA-181 (2 isolates). blaNDM-5 was identified in phylogenetic groups A, B1, and D isolates belonging to various genotypes (ST101, ST354, ST405, ST410, ST1196) associated with blaTEM-1, blaCTX-M-15, blaOXA-181, blaCMY-2, blaCMY-6, blaCMY-42, qnrB, qnrS, or aac6'-Ib-cr. While two isolates with blaOXA-181 belonged to phylogenetic group A-ST410, one isolate had also blaNDM-5, as well as blaCTX-M-15 and blaCMY-2, and the other harbored blaCMY-42 and aac6'-Ib-cr, showing different resistance patterns. Phylogenetic group B2 isolates examined were classified into mostly ST131 and had solely blaCTX-M-15 or blaCTX-M-27, harboring more virulence factors than other phylogenetic groups. The present study revealed high prevalence of ESBL genes represented by blaCTX-M-15 and dominance of blaNDM-5 among NDM genes, disseminating to various E. coli clones. Notably, carbapenemase gene encoding OXA-181 was first identified in Myanmar, suggesting its spread together with NDM genes.
Meiji Soe Aung; Nilar San; Win Win Maw; Thida San; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Clinical Isolates of Escherichia coli in Myanmar: Dominance of blaNDM-5 and Emergence of blaOXA-181. Microbial Drug Resistance 2018, 24, 1333 -1344.
AMA StyleMeiji Soe Aung, Nilar San, Win Win Maw, Thida San, Noriko Urushibara, Mitsuyo Kawaguchiya, Ayako Sumi, Nobumichi Kobayashi. Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Clinical Isolates of Escherichia coli in Myanmar: Dominance of blaNDM-5 and Emergence of blaOXA-181. Microbial Drug Resistance. 2018; 24 (9):1333-1344.
Chicago/Turabian StyleMeiji Soe Aung; Nilar San; Win Win Maw; Thida San; Noriko Urushibara; Mitsuyo Kawaguchiya; Ayako Sumi; Nobumichi Kobayashi. 2018. "Prevalence of Extended-Spectrum Beta-Lactamase and Carbapenemase Genes in Clinical Isolates of Escherichia coli in Myanmar: Dominance of blaNDM-5 and Emergence of blaOXA-181." Microbial Drug Resistance 24, no. 9: 1333-1344.
Purpose. Among the pneumococcal proteins, pneumococcal surface protein A (PspA) is considered the most promising candidate for a serotype-independent vaccine. This study aimed to investigate the serotype, genetic diversity of PspA, lineage (genotype) and drug resistance traits of pneumococcal isolates from paediatric patients. Methodology. A total of 678 non-invasive pneumococcal isolates obtained from June to November 2016 were analysed. All isolates were characterized for PspA families, serotypes and macrolide resistance genes. Seventy-one representative isolates of non-vaccine serotypes (NVTs) were genetically analysed for the clade-defining region (CDR) of PspA, as well as multi-locus sequence typing (MLST). Results. The detection rate of NVTs was 87.9 % (n=596), including dominant NVTs 15A (14.5 %, n=98), 35B (11.8 %, n=80), 15C (9.3 %, n=63) and 23A (9.0 %, n=61). Most isolates (96.6 %) possessed macrolide resistance genes erm(B) and/or mef(A/E). PspA families 1, 2 and 3 were detected in 42.3, 56.6 and 0.6 % of isolates, respectively. Nucleotide sequences of CDR showed high identity (90–100 %) within the same PspA clade, although the CDR identity among different PspA families ranged from 53 to 69 %. All isolates of NVTs 23A, 10A, 34, 24, 22F/22A, 33F, 23B and 38 were from PspA family 1, while NVTs 35B, 15C, 15B and 11A/11D isolates were from family 2. In contrast, genetically distinct PspAs were found in NVTs 6C and 15A. PspA family 3/clade 6 was detected in only NVT serotype 37 isolates assigned to ST447 and ST7970, showing the mucoid phenotype. Conclusion. The present study revealed the predominance of PspA families 1 and 2 in NVTs, and the presence of family 3 in serotype 37.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Shigeo Morimoto; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. Genetic diversity of pneumococcal surface protein A (PspA) in paediatric isolates of non-conjugate vaccine serotypes in Japan. Journal of Medical Microbiology 2018, 67, 1130 -1138.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Shigeo Morimoto, Masahiko Ito, Kenji Kudo, Nobumichi Kobayashi. Genetic diversity of pneumococcal surface protein A (PspA) in paediatric isolates of non-conjugate vaccine serotypes in Japan. Journal of Medical Microbiology. 2018; 67 (8):1130-1138.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Shigeo Morimoto; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. 2018. "Genetic diversity of pneumococcal surface protein A (PspA) in paediatric isolates of non-conjugate vaccine serotypes in Japan." Journal of Medical Microbiology 67, no. 8: 1130-1138.
High-level fluoroquinolone resistance is conferred by the mutation of conserved serine and acidic amino acids in the quinolone resistance-determining region (QRDR) of the A subunits of the type II topoisomerases, DNA gyrase (GyrA) and topoisomerase IV (ParC). In Japan, fluoroquinolone-resistant Enterococcus faecium continues to emerge in clinical settings. We analyzed 131 Japanese E. faecium clinical isolates for susceptibility to levofloxacin (LVFX), and QRDR mutational status. The bacterial collection had a high percentage of resistance (79%) and showed elevated drug minimal inhibitory concentrations (MICs). Eighty-three isolates had single or combined mutations in gyrA and/or parC; all were resistant to LVFX. A strong correlation was evident between log-transformed MICs and the total number of QRDR mutations (r = 0.7899), confirming the involvement of QRDR mutations in drug resistance, as previously described. Three-dimensional modeling indicated that the amino acid change(s) in QRDR could disrupt the interaction between the enzymes and drugs: the most common cause of quinolone resistance. Interestingly, eight isolates had a single mutation on gyrA and exhibited significantly reduced susceptibility. These data imply that either DNA gyrase or topoisomerase IV can be the primary target of fluoroquinolones, although topoisomerase IV is commonly thought to be the primary target in gram-positive bacteria.
Noriko Urushibara; Keisuke Suzaki; Mitsuyo Kawaguchiya; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi. Contribution of Type II Topoisomerase Mutations to Fluoroquinolone Resistance inEnterococcus faeciumfrom Japanese Clinical Setting. Microbial Drug Resistance 2018, 24, 1 -7.
AMA StyleNoriko Urushibara, Keisuke Suzaki, Mitsuyo Kawaguchiya, Meiji Soe Aung, Masaaki Shinagawa, Satoshi Takahashi, Nobumichi Kobayashi. Contribution of Type II Topoisomerase Mutations to Fluoroquinolone Resistance inEnterococcus faeciumfrom Japanese Clinical Setting. Microbial Drug Resistance. 2018; 24 (1):1-7.
Chicago/Turabian StyleNoriko Urushibara; Keisuke Suzaki; Mitsuyo Kawaguchiya; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi. 2018. "Contribution of Type II Topoisomerase Mutations to Fluoroquinolone Resistance inEnterococcus faeciumfrom Japanese Clinical Setting." Microbial Drug Resistance 24, no. 1: 1-7.
Asymptomatic carriers of toxigenic Staphylococcus aureus are potential source of diseases, including food poisoning. Toxigenic potential and genetic traits of colonizing S. aureus were investigated for 563 healthy food handlers in Myanmar. Carriage of S. aureus was found in 110 individuals (19.5%), and a total of 144 S. aureus isolates were recovered from nasal cavities (110 isolates) and hands (34 isolates). Panton-Valentine leucocidin genes (pvl) were detected in 18 isolates (12.5%), among which 11 isolates were classified into coa-VIa, agr type III, and ST1930 (CC96) that had been also detected in pvl-positive clinical isolates in Myanmar. A pvl-positive, ST2250 nasal isolate was identified as S. argenteus, a novel coagulase-positive staphylococcus species. Toxic shock syndrome toxin-1 (TSST-1) gene was detected in five pvl-negative isolates. All of the 144 isolates harbored at least one of the 21 enterotoxin(-like) gene(s). The most prevalent enterotoxin(-like) gene was selw (98%), followed by selx (97%), sei (28%), sely (28%), sem (26%), sel (24%), and sea and sec (22% each). Considerable genetic diversity with five groups was detected for selw. The present study revealed the relatively high rate of pvl, as well as the wide distribution of enterotoxin(-like) genes among colonizing S. aureus in Myanmar.
Meiji Soe Aung; Thida San; Mya Mya Aye; San Mya; Win Win Maw; Khin Nyein Zan; Wut Hmone Win Htut; Mitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar. Toxins 2017, 9, 241 .
AMA StyleMeiji Soe Aung, Thida San, Mya Mya Aye, San Mya, Win Win Maw, Khin Nyein Zan, Wut Hmone Win Htut, Mitsuyo Kawaguchiya, Noriko Urushibara, Nobumichi Kobayashi. Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar. Toxins. 2017; 9 (8):241.
Chicago/Turabian StyleMeiji Soe Aung; Thida San; Mya Mya Aye; San Mya; Win Win Maw; Khin Nyein Zan; Wut Hmone Win Htut; Mitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. 2017. "Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar." Toxins 9, no. 8: 241.
Since the implementation of routine PCV13 immunization in Japan, nonvaccine serotypes (NVTs) have been increasing among clinical isolates of Streptococcus pneumoniae. In this study, susceptibility to 18 antibiotics was tested for all the 231 isolates with NVTs, which were collected from children 90.9%), tetracycline (91.3%), and clindamycin (75.3%), while penicillin (PEN) nonsusceptibility (PNSP; MIC ≥0.12 μg/ml) was detected in 42.9% of the pneumococci [39.4%; PEN-intermediate S. pneumoniae (PISP), 3.5%; PEN-resistant S. pneumoniae (PRSP)]. All serotype 15A isolates were PRSP (MIC, ≥2 μg/ml) or PISP, and PNSP was prevalent in also serotypes 23A (96.9%), 6C (41%), and 35B (33.3%). Overall, 42.0% of the isolates showed multidrug resistance (MDR). Sequence types (STs) determined for 20 PNSP isolates with NVTs were ST63 (15A), STs 242 or 5832 (6C), STs 338 or 5242 (23A), and ST558 (35B). All the PNSP isolates possessed tet(M), and erm(B) or mefA(A/E), and 70% of them were gPRSP having three altered genes pbp1a, pbp2x, and pbp2b. Among alterations in transpeptidase-coding region of penicillin-binding proteins (PBPs), two substitutions of T371S in the STMK motif and TSQF574–577NTGY in PBP1a were common to all PRSP isolates. The present study showed the spread of PNSP in NVTs 15A, 23A, 6C, and 35B, and the emergence of the MDR international clone Sweden15A-ST63 in northern Japan.
Mitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. Multidrug Resistance in Non-PCV13 Serotypes ofStreptococcus pneumoniaein Northern Japan, 2014. Microbial Drug Resistance 2017, 23, 206 -214.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Nobumichi Kobayashi. Multidrug Resistance in Non-PCV13 Serotypes ofStreptococcus pneumoniaein Northern Japan, 2014. Microbial Drug Resistance. 2017; 23 (2):206-214.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. 2017. "Multidrug Resistance in Non-PCV13 Serotypes ofStreptococcus pneumoniaein Northern Japan, 2014." Microbial Drug Resistance 23, no. 2: 206-214.
High prevalence of Rickettsia felis in patients with fever of unknown origin was revealed in the north-central Bangladesh from 2012 to 2013. Subsequently, in this study, prevalence of R. felis in cats and cat fleas (Ctenocephalides felis), together with febrile patients, was studied by PCR detection of 17 kDa antigen gene and DNA sequencing. R. felis was detected in 28% (28/100) and 21% (14/68) of cat blood and cat flea samples, respectively, whereas 42% (21/50) of patients were positive for R. felis. R. felis-positive cat fleas were detected at significantly higher rate on R. felis-positive cats. The results suggested a potential role of cats and cat fleas for transmission of R. felis to humans in Bangladesh.
Rajib Ahmed; Shyamal Kumar Paul; Muhammad Akram Hossain; Salma Ahmed; Muhammad Chand Mahmud; Syeda Anjuman Nasreen; Faria Ferdouse; Rumana Hasan Sharmi; Farid Ahamed; Souvik Ghosh; Noriko Urushibara; Meiji Soe Aung; Nobumichi Kobayashi. Molecular Detection ofRickettsia felisin Humans, Cats, and Cat Fleas in Bangladesh, 2013–2014. Vector-Borne and Zoonotic Diseases 2016, 16, 356 -358.
AMA StyleRajib Ahmed, Shyamal Kumar Paul, Muhammad Akram Hossain, Salma Ahmed, Muhammad Chand Mahmud, Syeda Anjuman Nasreen, Faria Ferdouse, Rumana Hasan Sharmi, Farid Ahamed, Souvik Ghosh, Noriko Urushibara, Meiji Soe Aung, Nobumichi Kobayashi. Molecular Detection ofRickettsia felisin Humans, Cats, and Cat Fleas in Bangladesh, 2013–2014. Vector-Borne and Zoonotic Diseases. 2016; 16 (5):356-358.
Chicago/Turabian StyleRajib Ahmed; Shyamal Kumar Paul; Muhammad Akram Hossain; Salma Ahmed; Muhammad Chand Mahmud; Syeda Anjuman Nasreen; Faria Ferdouse; Rumana Hasan Sharmi; Farid Ahamed; Souvik Ghosh; Noriko Urushibara; Meiji Soe Aung; Nobumichi Kobayashi. 2016. "Molecular Detection ofRickettsia felisin Humans, Cats, and Cat Fleas in Bangladesh, 2013–2014." Vector-Borne and Zoonotic Diseases 16, no. 5: 356-358.
Twenty-two of 1,103 methicillin-resistant Staphylococcus aureus (MRSA) isolates containing the type II staphylococcal cassette chromosome mec element (SCC mec ) (collected in Hokkaido, Japan, from 2008 to 2011) harbored the arginine catabolic mobile element (ACME). Five genetic variations were identified in the ACME-staphylococcal cassette chromosome mec composite islands, 66 to 79 kb in size. The percentage of ACME carriage temporally increased from 0.85% to 4.5% in parallel with the emergence of shorter variants (66 to 72 kb). Shorter variants may have a selective advantage and accelerate the dissemination of ACME in Japanese MRSA.
Noriko Urushibara; Mitsuyo Kawaguchiya; Mayumi Onishi; Keiji Mise; Meiji Soe Aung; Nobumichi Kobayashi. Novel Structures and Temporal Changes of Arginine Catabolic Mobile Elements in Methicillin-Resistant Staphylococcus aureus Genotypes ST5-MRSA-II and ST764-MRSA-II in Japan. Antimicrobial Agents and Chemotherapy 2016, 60, 3119 -3122.
AMA StyleNoriko Urushibara, Mitsuyo Kawaguchiya, Mayumi Onishi, Keiji Mise, Meiji Soe Aung, Nobumichi Kobayashi. Novel Structures and Temporal Changes of Arginine Catabolic Mobile Elements in Methicillin-Resistant Staphylococcus aureus Genotypes ST5-MRSA-II and ST764-MRSA-II in Japan. Antimicrobial Agents and Chemotherapy. 2016; 60 (5):3119-3122.
Chicago/Turabian StyleNoriko Urushibara; Mitsuyo Kawaguchiya; Mayumi Onishi; Keiji Mise; Meiji Soe Aung; Nobumichi Kobayashi. 2016. "Novel Structures and Temporal Changes of Arginine Catabolic Mobile Elements in Methicillin-Resistant Staphylococcus aureus Genotypes ST5-MRSA-II and ST764-MRSA-II in Japan." Antimicrobial Agents and Chemotherapy 60, no. 5: 3119-3122.
Puerperal infection is a common complication during postnatal period in developing countries. Bacterial species, drug resistance, and genetic characteristics were investigated for a total of 470 isolates from puerperal infections in Bangladesh for a 2-year period (2010-2012). The most common species was Escherichia coli (n=98), followed by Enterococcus faecalis (n=54), Staphylococcus haemolyticus (n=33), Proteus mirabilis (n=32), Staphylococcus aureus (n=27), Klebsiella pneumoniae (n=22), and Enterobacter cloacae (n=21). S. aureus and Acinetobacter baumannii were isolated at a higher frequency from wound infections after cesarean section, while E. coli, E. cloacae, and K. pneumoniae were isolated from community-acquired endometritis and urinary tract infections. Resistance to third-generation cephalosporins was frequent for Enterobacteriacae, and was mainly mediated by blaCTX-M-1 group beta-lactamases. The CTX-M gene in E. coli from the four phylogroups was identified as blaCTX-M-15, and phylogroup B2 isolates with blaCTX-M-15 were classified into ST131 with O25b allele, harboring aac(6')-Ib-cr and various virulence factors. Carbapenemase genes blaNDM-1 and blaNDM-7 were identified in one isolate each of phylogroup A E. coli. Methicillin-resistant S. aureus isolates had type IV or V SCCmec, including isolates of ST361 (CC672), which is related to an emerging ST672 clone in the Indian subcontinent. This study revealed the recent epidemiological status of aerobic bacteria causing puerperal infections in Bangladesh, providing useful information to improve clinical practice and infection control.
Salma Ahmed; Mitsuyo Kawaguchiya; Souvik Ghosh; Shyamal Kumar Paul; Noriko Urushibara; Chand Mahmud; Kamrun Nahar; Mohammad Akram Hossain; Nobumichi Kobayashi. Drug Resistance and Molecular Epidemiology of Aerobic Bacteria Isolated from Puerperal Infections in Bangladesh. Microbial Drug Resistance 2015, 21, 297 -306.
AMA StyleSalma Ahmed, Mitsuyo Kawaguchiya, Souvik Ghosh, Shyamal Kumar Paul, Noriko Urushibara, Chand Mahmud, Kamrun Nahar, Mohammad Akram Hossain, Nobumichi Kobayashi. Drug Resistance and Molecular Epidemiology of Aerobic Bacteria Isolated from Puerperal Infections in Bangladesh. Microbial Drug Resistance. 2015; 21 (3):297-306.
Chicago/Turabian StyleSalma Ahmed; Mitsuyo Kawaguchiya; Souvik Ghosh; Shyamal Kumar Paul; Noriko Urushibara; Chand Mahmud; Kamrun Nahar; Mohammad Akram Hossain; Nobumichi Kobayashi. 2015. "Drug Resistance and Molecular Epidemiology of Aerobic Bacteria Isolated from Puerperal Infections in Bangladesh." Microbial Drug Resistance 21, no. 3: 297-306.