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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.
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.
Pneumococcal isolates from adult patients in northern Japan in 2016 were subjected to molecular investigation related to pneumococcal surface protein A (PspA) and drug resistance determinants. Of the 51 isolates, serotype 3/ST180 was the most prevalent (17.6%), followed by 35B (ST2755/ST558) (11.8%) and 15A (ST63/ST7874/ST13068/ST13785) (9.8%). Coverage of serotypes by 13-valent conjugate vaccine and 23-valent polysaccharide vaccine was 27.5% and 49%, respectively. All the isolates expressed PspA family 1 or 2 (51% and 49%, respectively). Each serotype was associated with either of the PspA families (e.g., serotype 3, PspA family 1; serotypes 35B and 15A, PspA family 2). Multidrug resistance (MDR) was found in 84.3% of the isolates. Minimum of one altered penicillin-binding protein gene was detected in 82.4% of isolates, indicating 25.5% non-susceptibility to penicillin. Serotypes 15A and 35B were predominant and demonstrated MDR. An isolate of serotype 15A/ST13785 (single-locus variant of ST242) was resistant to fluoroquinolones associated with double mutation in the quinolone resistance-determining regions of gyrA and parC. The present study indicates the spread of MDR pneumococci represented by isolates of serotypes 3, 15A, and 35B, and prevalence of both PspA family 1 and 2 in isolates obtained from adult patients.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Satoshi Habadera; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. Association Between Pneumococcal Surface Protein A Family and Genetic/Antimicrobial Resistance Traits of Non-Invasive Pneumococcal Isolates from Adults in Northern Japan. Microbial Drug Resistance 2019, 25, 744 -751.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Satoshi Habadera, Masahiko Ito, Kenji Kudo, Nobumichi Kobayashi. Association Between Pneumococcal Surface Protein A Family and Genetic/Antimicrobial Resistance Traits of Non-Invasive Pneumococcal Isolates from Adults in Northern Japan. Microbial Drug Resistance. 2019; 25 (5):744-751.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Satoshi Habadera; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. 2019. "Association Between Pneumococcal Surface Protein A Family and Genetic/Antimicrobial Resistance Traits of Non-Invasive Pneumococcal Isolates from Adults in Northern Japan." Microbial Drug Resistance 25, no. 5: 744-751.
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.
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.
Purpose. In Japan, the 7-valent pneumococcal vaccine (PCV7) was introduced in 2010 and, in 2013, the PCV7 was replaced with the 13-valent pneumococcal vaccine (PCV13). This study was conducted to investigate serotypes, antimicrobial resistance and prevalence of pilus islets in pneumococcal isolates from inpatients in a Japanese tertiary hospital. Methodology. From April 2011 to February 2016, 151 isolates [95 (18 children, 77 adults) and 56 (19 children, 37 adults) in the PCV7 and PCV13 periods, respectively] were collected. All isolates were serotyped using genetic methods and were tested for susceptibility to 18 antimicrobials. Unaltered penicillin-binding protein (PBP) genes, macrolide resistance genes and pilus islets were identified by PCR. Results. Between the two periods, the prevalence of non-PCV13 serotypes was shown to increase from 50.0 to 78.9 % in children, and serotype 3 increased from 14.3 to 24.3 % in adults. Six of seven isolates from invasive diseases were assigned to non-PCV13 serotypes. Overall, multidrug resistance (MDR) was detected in 46.4 % of isolates, which included the dominant non-PCV13 serotypes 6E, 15A and 23A (prevalence≥75.0 %). gPRSP (three altered genes pbp1a, pbp2b and pbp2x) and macrolide resistance genes [erm(B) and/or mef(A/E)] were detected in 35.8 and 93.4 % of all isolates, respectively. Pilus islets [PI-1 (clade I, II and III) and/or PI-2] were found in 22.5 % (34/151) of isolates belonging to six different serotypes (19F, 23F, 19A, 6E, 15B and 35B) and 88.2 % (30/34) of these exhibited MDR. Conclusion. This study revealed the spread of MDR in several non-PCV13 serotypes and in isolates with pilus islets.
Mitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi. Serotype distribution, antimicrobial resistance and prevalence of pilus islets in pneumococci following the use of conjugate vaccines. Journal of Medical Microbiology 2017, 66, 643 -650.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Meiji Soe Aung, Masaaki Shinagawa, Satoshi Takahashi, Nobumichi Kobayashi. Serotype distribution, antimicrobial resistance and prevalence of pilus islets in pneumococci following the use of conjugate vaccines. Journal of Medical Microbiology. 2017; 66 (5):643-650.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Meiji Soe Aung; Masaaki Shinagawa; Satoshi Takahashi; Nobumichi Kobayashi. 2017. "Serotype distribution, antimicrobial resistance and prevalence of pilus islets in pneumococci following the use of conjugate vaccines." Journal of Medical Microbiology 66, no. 5: 643-650.
Serotype 23B Streptococcus pneumoniae was isolated from a 67-year-old Japanese patient with meningitis. This isolate was susceptible to penicillin G, while genotyped as gPISP with a mutation in a penicillin-binding motif in PBP2b. The 23B isolate was assigned to ST11996 that is related to CC439, a dominant group among serotype 23B.
A. Takamatsu; M. Kawaguchiya; B. Chang; M. Ito; Y. Hirano; S. Katsuta; S. Matsuzaka; Y. Serizawa; N. Kobayashi. First report of serotype 23B Streptococcus pneumoniae isolated from an adult patient with invasive infection in Japan. New Microbes and New Infections 2017, 17, 96 -97.
AMA StyleA. Takamatsu, M. Kawaguchiya, B. Chang, M. Ito, Y. Hirano, S. Katsuta, S. Matsuzaka, Y. Serizawa, N. Kobayashi. First report of serotype 23B Streptococcus pneumoniae isolated from an adult patient with invasive infection in Japan. New Microbes and New Infections. 2017; 17 ():96-97.
Chicago/Turabian StyleA. Takamatsu; M. Kawaguchiya; B. Chang; M. Ito; Y. Hirano; S. Katsuta; S. Matsuzaka; Y. Serizawa; N. Kobayashi. 2017. "First report of serotype 23B Streptococcus pneumoniae isolated from an adult patient with invasive infection in Japan." New Microbes and New Infections 17, no. : 96-97.
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.
In Japan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced to the nation's routine immunization program in April 2013 and was replaced by the 13-valent pneumococcal conjugate vaccine (PCV13) in November 2013. Distribution of serotypes and macrolide resistance genotypes was investigated for a total of 1097 (975 children, 122 adults) and 960 (873 children, 87 adults) clinical isolates of Streptococcus pneumoniae from noninvasive infections in Hokkaido (northern main island of Japan) in the routine immunization periods for PCV7 and PCV13 (April–October 2013 and November 2013–November 2014, respectively). Serotype was determined by sequential multiplex PCR and additional genetic analyses. Macrolide resistance genes erm(B) and mef(A/E) were detected by multiplex PCR. Although the most prevalent serotypes in children were 23A and 6C in the PCV7 period, after replacement with PCV13, 19A became the most common, followed by 6C, 15A and 23A. Among adults, serotype 3 was consistently the most frequent throughout the study periods. Compared with values from the pre-PCV7 routine immunization period, PCV7 serotypes decreased from 48.3 to 3.3% in the PCV13 period among children, while the rates of non-PCV13 serotypes (particularly 15A, 23A, 11A, 10A and 35B) increased from 39.7 to 75.1% (p < 0.001). In the PCV13 period, erm(B), mef(A/E) and both of these genes were detected in 75.8, 31.6 and 11.3% of all isolates, respectively. Serotype 19A accounted for 76.9% of the isolates with both the macrolide resistance genes, and emerging non-PCV13 serotypes 15A, 15C and 23A mostly harboured erm(B).
M. Kawaguchiya; N. Urushibara; M.S. Aung; S. Morimoto; M. Ito; K. Kudo; A. Sumi; N. Kobayashi. Emerging non-PCV13 serotypes of noninvasive Streptococcus pneumoniae with macrolide resistance genes in northern Japan. New Microbes and New Infections 2015, 9, 66 -72.
AMA StyleM. Kawaguchiya, N. Urushibara, M.S. Aung, S. Morimoto, M. Ito, K. Kudo, A. Sumi, N. Kobayashi. Emerging non-PCV13 serotypes of noninvasive Streptococcus pneumoniae with macrolide resistance genes in northern Japan. New Microbes and New Infections. 2015; 9 ():66-72.
Chicago/Turabian StyleM. Kawaguchiya; N. Urushibara; M.S. Aung; S. Morimoto; M. Ito; K. Kudo; A. Sumi; N. Kobayashi. 2015. "Emerging non-PCV13 serotypes of noninvasive Streptococcus pneumoniae with macrolide resistance genes in northern Japan." New Microbes and New Infections 9, no. : 66-72.
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.
Serogroup 6 of Streptococcus pneumoniae contains four established serotypes (6A-6D). Recently, putative serotype 6E (genotype 6E) was proposed as a novel type, which is cross-reactive with 6B-specific antiserum, but its capsular polysaccharide synthesis (cps) locus is genetically distinct from those of serotypes 6A and 6B. In the present study, prevalence of genotype 6E was analyzed by a newly designed multiplex polymerase chain reaction (PCR) for noninvasive or colonizing S. pneumoniae isolates in northern Japan assigned to serogroup 6 in our previous study by the sequential multiplex PCR developed by Pai et al. Among the isolates previously assigned to 6A and 6B, 2.2% (1/45) and 77.3% (140/181) of isolates, respectively, were revealed to have cps genes of genotype 6E. Eight 6E isolates selected for further analysis were found to have identical or highly similar sequences of cps genes (wzg, wzh, wze, wciN, wciP, and wzy) to those of strains previously reported as putative serotype 6E, and all the isolates were classified into sequence type 90 (ST90). Reanalysis of genetic traits on penicillin and macrolide resistance clarified significantly higher rates of three pbp mutations (gPRSP) and ermB in genotype 6E than in serotypes 6A and 6B. These findings suggested a need for detection of genotype 6E in the surveillance of S. pneumoniae serotypes.
Mitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. High Prevalence of Genotype 6E (Putative Serotype 6E) Among Noninvasive/Colonization Isolates ofStreptococcus pneumoniaein Northern Japan. Microbial Drug Resistance 2015, 21, 209 -214.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Nobumichi Kobayashi. High Prevalence of Genotype 6E (Putative Serotype 6E) Among Noninvasive/Colonization Isolates ofStreptococcus pneumoniaein Northern Japan. Microbial Drug Resistance. 2015; 21 (2):209-214.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Nobumichi Kobayashi. 2015. "High Prevalence of Genotype 6E (Putative Serotype 6E) Among Noninvasive/Colonization Isolates ofStreptococcus pneumoniaein Northern Japan." Microbial Drug Resistance 21, no. 2: 209-214.
Distribution of serotypes, prevalence of resistance to penicillin and/or erythromycin (EM), and its genetic traits were analyzed for a total of 1,061 noninvasive or colonization isolates of Streptococcus pneumoniae (998 and 61 isolates from children and adults, respectively) in Hokkaido, northern main island of Japan, in the year 2011, the pre-PCV7 routine immunization period. Serotype deduction was performed by sequential multiplex polymerase chain reaction (PCR), employing mutagenic PCR-restriction fragment length polymorphism for discrimination of 6A/C and 6B/D. Unaltered three PBP genes and macrolide resistance genes erm(B) and mef(A/E) were detected by multiplex PCR. Among isolates from children, 25 serotypes, including the prevalent types 6B (17.5%), 19F (15.6%), 23F (12.2%), and 6C (11.6%), were identified, revealing the PCV7 and PCV13 coverage rates as 48.2% and 60.3%, respectively, while serotype 3 was the most frequent (19.0%) among isolates from adults. Most of the pediatric isolates (96.8%) exhibited resistance to EM (minimum inhibitory concentration [MIC], ≥1 μg/ml), with a higher prevalence of erm(B) (67.2%) than mef(A/E) (39.7%). erm(B) was associated with high-level EM resistance (MIC, ≥128 μg/ml) and distributed at high detection rates to major serotypes 23F (85.2%) and 6B (85.1%), as well as minor serotypes 3, 10A, 14, 15B, 15C, 19A, and 23A (>90%). While penicillin-resistant S. pneumoniae (PRSP) (penicillin G-MIC, 2-3 μg/ml) was detected in 7.8% of isolates from children, the most common PBP gene genotype was gPRSP (three altered genes pbp1a, 2x, and 2b; 38.3%), which was detected at higher rates (>60%) in the dominant serotypes 23F, 6B, and 19F, and minor serotypes 6D and 15A. Dominant serotypes in the S. pneumoniae isolates were generally similar to those reported for invasive strains, despite lower coverage rates by PCV7/13. The importance of further surveillance on incidence and drug resistance in the post-PCV7 period was suggested for non-PCV7/13 serotypes 6C, 6D, 10A, 15A, 15B, 15C, 23A, and 35B.
Mitsuyo Kawaguchiya; Noriko Urushibara; Souvik Ghosh; Osamu Kuwahara; Shigeo Morimoto; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. Serotype Distribution and Susceptibility to Penicillin and Erythromycin Among Noninvasive or Colonization Isolates ofStreptococcus pneumoniaein Northern Japan: A Cross-Sectional Study in the Pre-PCV7 Routine Immunization Period. Microbial Drug Resistance 2014, 20, 456 -465.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Souvik Ghosh, Osamu Kuwahara, Shigeo Morimoto, Masahiko Ito, Kenji Kudo, Nobumichi Kobayashi. Serotype Distribution and Susceptibility to Penicillin and Erythromycin Among Noninvasive or Colonization Isolates ofStreptococcus pneumoniaein Northern Japan: A Cross-Sectional Study in the Pre-PCV7 Routine Immunization Period. Microbial Drug Resistance. 2014; 20 (5):456-465.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Souvik Ghosh; Osamu Kuwahara; Shigeo Morimoto; Masahiko Ito; Kenji Kudo; Nobumichi Kobayashi. 2014. "Serotype Distribution and Susceptibility to Penicillin and Erythromycin Among Noninvasive or Colonization Isolates ofStreptococcus pneumoniaein Northern Japan: A Cross-Sectional Study in the Pre-PCV7 Routine Immunization Period." Microbial Drug Resistance 20, no. 5: 456-465.
The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL+ and/or ACME+S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. The PVL gene was identified in three MRSA strains with SCCmec IV, which belonged to ST8, spa type t008, coagulase type III, and agr type I. Two PVL-positive MRSA strains had also type I ACME, and were isolated from skin abscess of outpatients who have not travelled abroad recently. One of these PVL+/ACME+ strains carried tet(K), msrA, and aph(3′)-IIIa, showing resistance to kanamycin, tetracycline, erythromycin, and ciprofloxacin, suggesting acquisition of more resistance than ST8 CA-MRSA reported in Japan previously. In contrast, another PVL+/ACME+ strain and a PVL+/ACME− strain were susceptible to more antimicrobials and had less virulence factors than PVL−/ACME+ MRSA strains. Besides the two PVL+ MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL−/ACME+ MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL−/ACME− MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.
Mitsuyo Kawaguchiya; Noriko Urushibara; Dai Yamamoto; Toshiharu Yamashita; Masaaki Shinagawa; Naoki Watanabe; Nobumichi Kobayashi. Characterization of PVL/ACME-Positive Methicillin-ResistantStaphylococcus aureus(Genotypes ST8-MRSA-IV and ST5-MRSA-II) Isolated from a University Hospital in Japan. Microbial Drug Resistance 2013, 19, 48 -56.
AMA StyleMitsuyo Kawaguchiya, Noriko Urushibara, Dai Yamamoto, Toshiharu Yamashita, Masaaki Shinagawa, Naoki Watanabe, Nobumichi Kobayashi. Characterization of PVL/ACME-Positive Methicillin-ResistantStaphylococcus aureus(Genotypes ST8-MRSA-IV and ST5-MRSA-II) Isolated from a University Hospital in Japan. Microbial Drug Resistance. 2013; 19 (1):48-56.
Chicago/Turabian StyleMitsuyo Kawaguchiya; Noriko Urushibara; Dai Yamamoto; Toshiharu Yamashita; Masaaki Shinagawa; Naoki Watanabe; Nobumichi Kobayashi. 2013. "Characterization of PVL/ACME-Positive Methicillin-ResistantStaphylococcus aureus(Genotypes ST8-MRSA-IV and ST5-MRSA-II) Isolated from a University Hospital in Japan." Microbial Drug Resistance 19, no. 1: 48-56.
The Group A rotavirus (RVA) P[10] is a rare genotype of the RVA VP4 gene. To date, the whole genome sequence of only a single P[10] RVA strain, RVA/Human-tc/IDN/69M/1980/G8P4[10], has been determined, revealing a DS-1-like genotype constellation. Whole genomic analyses of P[10] RVA strains with other VP7 genotypes are essential to obtain conclusive data on the origin and genetic diversity of the P10] RVAs. In the present study, the whole genome of a human G4P[10] RVA strain, RVA/Human-tc/IDN/57M/1980/G4P[10], was analyzed. Strain 57M exhibited an unusual G4-P[10]-I1-R1-C1-M1-A1-N1-T2-E1-H2 genotype constellation, and was found to originate from intergenogroup reassortment events involving acquisition of RVA strain 69M-like VP4, NSP3 and NSP5 genes by a co-circulating Wa-like human G4 RVA strain. Although the reference P[10] strain, 69M, exhibits a DS-1-like genotype constellation, the exact origin of this RVA remains to be elucidated. By detailed phylogenetic analyses, we found that the VP1-VP3, VP6, NSP2 and NSP4 genes of 69M originated from artiodactyl and/or artiodactyl-like human P[14] strains, whilst its NSP1, NSP3 and NSP5 genes were more related to those of typical human DS-1-like strains than those of other RVAs. On the other hand, the origin of the VP4 gene of 69M could not be established. Nevertheless, these observations clearly indicated that strain 69M might have originated from reassortment events involving at least the artiodactyl or artiodactyl-like human RVAs and the typical human DS-1-like strains. The present study provided rare evidence for intergenogroup reassortment events involving co-circulating typical human Wa-like RVAs and unusual RVAs of the DS-1-like genogroup, and revealed the presence of artiodactyl-like genes in a human P[10] strain, highlighting the complex evolutionary patterns of the P[10] RVAs.
Souvik Ghosh; Noriko Urushibara; Mitsuyo Kawaguchiya; Tsuzumi Shintani; Nobumichi Kobayashi. The origin of two rare human P[10] rotavirus strains. Infection, Genetics and Evolution 2013, 13, 292 -300.
AMA StyleSouvik Ghosh, Noriko Urushibara, Mitsuyo Kawaguchiya, Tsuzumi Shintani, Nobumichi Kobayashi. The origin of two rare human P[10] rotavirus strains. Infection, Genetics and Evolution. 2013; 13 ():292-300.
Chicago/Turabian StyleSouvik Ghosh; Noriko Urushibara; Mitsuyo Kawaguchiya; Tsuzumi Shintani; Nobumichi Kobayashi. 2013. "The origin of two rare human P[10] rotavirus strains." Infection, Genetics and Evolution 13, no. : 292-300.