RESUMO
All clinical isolates of Streptococcus dysgalactiae subsp. equisimilis (SDSE) are considered susceptible to ß-lactams, the first-line drugs used to treat SDSE infections. However, given that penicillin-non-susceptible SDSE strains have been isolated in Denmark, in this study, we aimed to identify ß-lactam-non-susceptible clinical isolates of SDSE in Japan. In 2018, we collected 150 clinical isolates of S. dysgalactiae, and species identification was performed using a Rapid ID Strep API kit. The minimum inhibitory concentrations (MIC) of six ß-lactams (penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor) were determined for the 85 clinical isolates identified as SDSE using the agar dilution method standardized by the Clinical & Laboratory Standards Institute. The MIC ranges of penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor were 0.007-0.06, 0.03-0.12, 0.015-0.06, 0.25-2, 0.12-2, and 0.06-0.5 µg/mL, respectively. None of the clinical isolates of SDSE were non-susceptible to penicillin G, indicating that all 85 clinical isolates of SDSE were susceptible to ß-lactams. Our findings indicate that almost all clinical isolates of SDSE, from several prefectures of Japan, are still susceptible to ß-lactams. Nevertheless, there remains a need for continuous and careful monitoring of drug susceptibility among clinical SDSE isolates in Japan.
Assuntos
Antibacterianos , Testes de Sensibilidade Microbiana , Infecções Estreptocócicas , Streptococcus , beta-Lactamas , Humanos , beta-Lactamas/farmacologia , Antibacterianos/farmacologia , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Streptococcus/classificação , Japão , Infecções Estreptocócicas/microbiologia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Adulto , Criança , Adulto Jovem , Idoso de 80 Anos ou mais , Pré-EscolarRESUMO
We compared rapid antigen detection kits widely used for the rapid diagnosis of group A streptococcal pharyngitis, evaluating their minimum detection sensitivity and operability in five levels. Five kits based on the immunochromatographic method were used: ImunoAce Strep A (Tauns), ImunoAce Strep A Neo (Tauns), Quick Navi-StrepA2 (Denka), Quick Vue Dipstick Strep A (SB Bioscience) and RapidTesta Strep A (SEKISUI MEDICAL). Thirteen strains were tested: 10 clinical isolates of Streptococcus pyogenes, 2 strains of Streptococcus dysgalactiae subsp. equisimilis (SDSE), and S. pyogenes ATCC 19615. All kits had the same or higher minimum detection sensitivity than previously reported. ImunoAce StrepA Neo had the highest detection sensitivity and the best overall evaluation among the group A streptococcal rapid antigen detection kits used in this study. The detection sensitivity of SDSE with group A polysaccharide antigen was comparable to that of S. pyogenes. Although culture tests are necessary to confirm the causative organism, SDSE may present with clinical symptoms similar to those of S. pyogenes, and detection with a rapid antigen detection kit may be of therapeutic value.
Assuntos
Faringite , Infecções Estreptocócicas , Humanos , Streptococcus pyogenes , Infecções Estreptocócicas/diagnóstico , Faringite/diagnóstico , Faringite/microbiologia , Kit de Reagentes para DiagnósticoRESUMO
Although community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged worldwide, no nationwide CA-MRSA surveillance has been conducted in Japan to determine the changes in its molecular characteristics over time. We aimed to characterize the molecular epidemiology of Panton-Valentine leucocidin (PVL)-positive CA-MRSA strains collected from across Japan in the past decade. We isolated 1,770 MRSA strains from the skin and pus samples of outpatients of 244 medical facilities in 31 prefectures between 2010 and 2018 (2010, 2012, 2014, 2016, and 2018). Regions, hospitals, and periods in which strains were isolated and patient age group and sex were tabulated. Staphylococcal cassette chromosome mec (SCCmec) typing, detection of virulence factor genes, and antimicrobial susceptibility testing were performed. Whole-genome analysis was performed for the PVL-positive strains isolated in 2018. All strains harbored the mecA gene. Compared to that in 2010, the percentage of SCCmec type IV increased in 2018, with a corresponding increase in the proportion of PVL-positive strains (10% to 26%). Of the isolates obtained in 2018, clonal complex 8 (CC8) was dominant among PVL-positive strains. Core-genome single-nucleotide polymorphism analysis, using whole-genome sequencing, suggested that the CC8 PVL-positive strains spread throughout Japan over the last decade. Furthermore, a unique ST22 clone carrying both the PVL- and toxic shock syndrome toxin-1-encoding genes has emerged. We demonstrated that the molecular epidemiology of CA-MRSA in Japan differs from that in Europe and the United States; thus, it is crucial to monitor the trend of changes in CA-MRSA characteristics in Japan. IMPORTANCE Community-associated MRSA, which is a multidrug-resistant organism and can cause infections in otherwise-healthy individuals, has become a global problem. This paper describes a nationwide surveillance conducted in Japan to investigate changes in molecular epidemiological characteristics of CA-MRSA over the past decade and provides a detailed review of the characteristics of Panton-Valentine leucocidin (PVL)-positive strains isolated in 2018. Although CA-MRSA is rare in Japan to date, we found that the isolation of PVL-positive strains has been increasing over the past decade. In particular, the PVL-positive strains wherein CC8 was dominant exhibited high interstrain similarity, suggesting that a limited number of clones have spread over the past decade. Furthermore, a unique ST22 clone carrying both PVL-encoding and toxic shock syndrome toxin-1-encoding genes has emerged. This study shows that various changes can be observed when molecular epidemiological analysis, combined with next-generation sequencing, is conducted over a long period.
Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Infecções Comunitárias Adquiridas/epidemiologia , Exotoxinas/genética , Humanos , Japão/epidemiologia , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/epidemiologia , Fatores de Virulência/genéticaRESUMO
The Enterobacter cloacae complex (ECC) is one of the most common causes of bacteremia and leads to poor clinical outcomes. The aim of this study was to clarify the antimicrobial susceptibility profiles and genetic backgrounds of non-carbapenemase-producing reduced-carbapenem-susceptible (RCS) ECC blood isolates in Japan using agar dilution antimicrobial susceptibility testing, whole-genome sequencing, and quantitative polymerase chain reaction for ampC, ompC, and ompF transcripts. Forty-two ECC blood isolates were categorized into RCS and carbapenem-susceptible groups based on the minimum inhibitory concentration of imipenem. The RCS ECC blood isolates belonged to distinct species and sequence types and produced varying class C ß-lactamases. The E. roggenkampii, E. asburiae, and E. bugandensis isolates belonged only to the RCS group. Some E. hormaechei ssp. steigerwaltii isolates from the RCS group exhibited AmpC overexpression caused by amino acid substitutions in AmpD and AmpR along with ompF downregulation. These findings suggest that non-carbapenemase-producing RCS ECC blood isolates are genetically diverse.
Assuntos
Carbapenêmicos , Infecções por Enterobacteriaceae , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Hemocultura , Carbapenêmicos/farmacologia , Enterobacter cloacae/genética , Infecções por Enterobacteriaceae/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , beta-Lactamases/genéticaRESUMO
We investigated the efficiency of the Verigene Enteric Pathogens Nucleic Acid Test (Verigene EP test), which is an automated microarray-based assay system that enables rapid and simultaneous genetic detection of gastrointestinal pathogens and toxins, including those in the Campylobacter Group, Salmonella species, Shigella species, the Vibrio Group, Yersinia enterocolitica, Shiga toxin 1 and 2, norovirus GI/GII, and rotavirus A. Three clinical laboratories evaluated the Verigene EP test, using 268 stool samples for bacterial and toxin genes and 167 samples for viral genes. Culture-based reference methods were used for the detection of bacteria and toxins, while a different molecular assay was used for viral detection. The overall concordance rate between the Verigene EP test and the reference methods for the 1940 assays was 99.0%. The overall sensitivity and specificity of the Verigene EP test were 97.0% and 99.3%, respectively. Of the 19 samples with discordant results, 13 samples were false positives and six were false negatives. The Verigene EP test simultaneously detected two targets in 11 samples; overall, the test demonstrated high efficiency in detecting crucial diarrheagenic pathogens, indicating its suitability for clinical practice.
Assuntos
Toxinas Bacterianas/isolamento & purificação , Diarreia/diagnóstico , Gastroenterite/microbiologia , Microbioma Gastrointestinal , Toxinas Bacterianas/genética , Diarreia/genética , Diarreia/microbiologia , Fezes/microbiologia , Gastroenterite/diagnóstico , Gastroenterite/genética , Humanos , Técnicas de Diagnóstico Molecular , Norovirus/genética , Norovirus/isolamento & purificação , Norovirus/patogenicidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Toxina Shiga I/química , Toxina Shiga I/genética , Toxina Shiga I/isolamento & purificação , Shigella/genética , Shigella/isolamento & purificação , Shigella/patogenicidadeRESUMO
OBJECTIVES: A standard treatment regimen against Mycobacteroides abscessus complex (MABC) infections has not yet been established, making MABC difficult to treat successfully. In this study, we sought to develop an active ingredient for the clinical treatment of MABC infections. METHODS: We screened 102 MABC strains isolated from clinical specimens using DNA sequence analysis with the housekeeping genes hsp65 and rpoB. Drug susceptibility testing was performed against two subspecies-Mycobacteroides abscessus subsp. abscessus (M. abscessus) and Mycobacteroides abscessus subsp. massiliense (M. massiliense)-using eight antimicrobial agents (clarithromycin, amikacin, doxycycline, imipenem, linezolid, moxifloxacin, faropenem, and rifampicin). The combined efficacy of the antimicrobial agents was investigated using a checkerboard method. RESULTS: We identified 51 isolates as M. abscessus, 46 as M. massiliense, and five as others. Most of the M. abscessus isolates (83.0 %) exhibited inducible resistance to clarithromycin via the expression of the erm(41) gene. Combinations of imipenem with linezolid, moxifloxacin, and rifampicin exhibited additive effects against 81.0 %, 40.7 %, and 26.9 % of M. abscessus, respectively, and against 54.5 %, 69.2 %, and 30.8 % of M. massiliense, respectively. CONCLUSIONS: These results demonstrated the potential efficacy of a regimen containing imipenem against M. abscessus and M. massiliense infections.
Assuntos
Antibacterianos/farmacologia , Mycobacteriaceae/efeitos dos fármacos , Infecções por Actinomycetales/microbiologia , Amicacina/farmacologia , Claritromicina/farmacologia , Doxiciclina/farmacologia , Humanos , Imipenem/farmacologia , Linezolida/farmacologia , Testes de Sensibilidade Microbiana , Moxifloxacina/farmacologia , Mycobacteriaceae/classificação , Mycobacteriaceae/crescimento & desenvolvimento , Análise de Sequência de DNA , beta-Lactamas/farmacologiaRESUMO
Recently, a new rapid assay for the detection of tcdB gene of Clostridioides difficile was developed using the GENECUBE. The assay can directly detect the tcdB gene from stool samples without a purification in approximately 35 minutes with a few minutes of preparation process. We performed a prospective comparative study of the performance of the assay at eight institutions in Japan. Fresh residual stool samples (Bristol stool scale ≥5) were used and comparisons were performed with the BD MAX Cdiff assay and toxigenic cultures. For the evaluation of 383 stool samples compared with the BD MAX Cdiff assay, the sensitivity, and specificity of the two assays was 99.0% (379/383), 98.1% (52/53), 99.1% (327/330), respectively. In the comparison with toxigenic culture, the total, sensitivity, and specificity were 96.6% (370/383), 85.0% (51/60), and 98.8% (319/323), respectively. The current investigation indicated the GENECUBE Clostridioides difficile assay has equivalent performance with the BD MAX Cdiff assay for the detection of tcdB gene of C. difficile.
Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Clostridioides difficile/genética , Fezes/microbiologia , Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/diagnóstico , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Enterotoxinas/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Kit de Reagentes para Diagnóstico , Proteínas Repressoras/genética , Sensibilidade e EspecificidadeRESUMO
OBJECTIVES: To characterise the genotypic profiles of methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates from companion animals and to investigate their association with those from humans in Japan. METHODS: Non-duplicated MRSA clinical isolates recovered between July 2016 and January 2018 were analysed. The MRSA isolates were typed by polymerase chain reaction (PCR)-based open reading frame (ORF) typing (POT) scores, SCCmec types, multilocus sequence typing, and virulence gene profiles. Phylogenetic comparison of those isolates with previously described human isolates was performed. RESULTS: Among 56 MRSA isolates (33 cats, 20 dogs and three rabbits), 26 isolates with a POT1 score of 93, SCCmec type II mostly belonged to CC5, including ST5. Twenty-six isolates with a POT1 score of 106, SCCmec type IV showed diversity of STs: 15 isolates belonged to CC8, mainly including ST8, and 11 isolates belonged to CC1, including ST1 and newly identified STs 4768, 4775, and 4779. Two cat isolates were ST8-SCCmec type IV possessing pvl/ACME-arcA, presumed to be the hypervirulent community-associated MRSA (CA-MRSA) clone USA300. Notably, all three rabbit isolates belonged to ST4768. The POT1 score 106 CA-MRSA isolates from animals and humans were divided into two large clusters of CC1 and CC8, where host species-specific sub-clusters were not identified within each cluster. A large cluster of POT1 score 93 healthcare-associated MRSA (HA-MRSA) isolates from animals and humans consisted of sub-clusters formed exclusively by the vast majority of human isolates and those formed by animal and human isolates. CONCLUSION: Companion animals could be potential reservoirs and vehicles for the transmission of CA-MRSA to humans, and could transmit companion animal-adaptive HA-MRSA lineages to humans as their second reservoirs.
Assuntos
Infecção Hospitalar/microbiologia , Staphylococcus aureus Resistente à Meticilina/classificação , Animais de Estimação/microbiologia , Infecções Estafilocócicas/microbiologia , Fatores de Virulência/genética , Animais , Gatos , Cães , Genótipo , Especificidade de Hospedeiro , Humanos , Japão , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Tipagem Molecular , Filogenia , Coelhos , Infecções Estafilocócicas/veterinária , Urina/microbiologiaRESUMO
Vancomycin-resistant enterococci are troublesome pathogens in clinical settings because of few treatment options. A VanA/VanM-type vancomycin-resistant Enterococcus faecium clinical isolate was identified in Japan. This strain, named AA708, harbored five plasmids, one of which migrated during agarose gel electrophoresis without S1 nuclease treatment, which is indicative of a linear topology. We named this plasmid pELF1. Whole genome sequencing (WGS) analysis of the AA708 strain revealed that the complete sequence of pELF1 was 143,316 bp long and harbored both the vanA and vanM gene clusters. Furthermore, mfold analysis and WGS data show that the left end of pELF1 presumably forms a hairpin structure, unlike its right end. The pELF1 plasmid was not digested by lambda exonuclease, indicating that terminal proteins were bound to the 5' end of the plasmid, similar to the Streptomyces linear plasmids. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis results were also consistent with the exonuclease assay results. In retardation assays, DNAs containing the right end of proteinase K-untreated pELF1 did not appear to move as well as the proteinase K-treated pELF1, suggesting that terminal proteins might be attached to the right end of pELF1. Palindromic sequences formed hairpin structures at the right terminal sequence of pELF1; however, sequence similarity with the well-known linear plasmids of Streptomyces spp. was not high. pELF1 was unique as it possessed two different terminal structures. Conjugation experiments revealed that pELF1 could be transferred to E. faecalis, E. faecium, E. casseliflavus, and E. hirae. These transconjugants exhibited not only high resistance levels to vancomycin, but also resistance to streptomycin, kanamycin, and erythromycin. These results indicate that pELF1 has the ability to confer multidrug resistance to Enterococcus spp. simultaneously, which might lead to clinical hazards.
RESUMO
BACKGROUND: VanB-type vancomycin (VAN) resistance gene clusters confer VAN resistances on Enterococcus spp. over a wide range of MIC levels (MIC = 4-1000 mg/L). However, the epidemiology and the molecular characteristics of the VAN susceptible VanB-type Enterococcus still remain unclear. RESULTS: We characterized 19 isolates of VanB-type Enterococcus faecium that might colonize in the gut and were not phenotypically resistant to VAN (MIC = 3 mg/L). They were obtained from two hospitals in Japan between 2009 and 2010. These isolates had the identical vanB gene cluster and showed same multilocus sequence typing (MLST) (ST78) and the highly related profiles in pulsed-field gel electrophoresis (PFGE). The vanB gene cluster was located on a plasmid, and was transferable to E. faecium and E. faecalis. Notably, from these VanB-type VREs, VAN resistant (MIC≥16 mg/L) mutants could appear at a frequency of 10- 6-10- 7/parent cell in vitro. Most of these revertants acquired mutations in the vanSB gene, while the remainder of the revertants might have other mutations outside of the vanB gene cluster. All of the revertants we tested showed increases in the VAN-dependent expression of the vanB gene cluster, suggesting that the mutations affected the transcriptional activity and increased the VAN resistance. Targeted mutagenesis revealed that three unique nucleotide substitutions in the vanB gene cluster of these strains attenuated VAN resistance. CONCLUSIONS: In summary, this study indicated that stealthy VanB-type E. faecium strains that have the potential ability to become resistance to VAN could exist in clinical settings.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/genética , Infecções por Bactérias Gram-Positivas/microbiologia , Proteínas de Bactérias/metabolismo , Eletroforese em Gel de Campo Pulsado , Enterococcus faecium/classificação , Enterococcus faecium/isolamento & purificação , Humanos , Japão , Família Multigênica , Tipagem de Sequências Multilocus , Mutação , Vancomicina/farmacologia , Resistência a VancomicinaRESUMO
An 83-year-old previously self-sufficient man was referred to our hospital for a fever, severe tenderness over the lumbar spine, and elevated C-reactive protein levels. Computed tomography revealed fluid collection in the intervertebral space of L3/4. Gram-positive, short rod-shaped bacteria were isolated from two sets of blood cultures. A 16S rRNA sequence analysis of an isolate showed a similarity of 98.1% to the nearest type strain Brachybacterium squillarum JCM 16464T. Biochemical characteristics of the presently isolated strain differed from those of the most closely related species of the genus Brachybacterium. The patient was successfully discharged on day 73 of admission with antimicrobial therapies and showed no recurrence during outpatient visits. Brachybacterium spp. have mainly been isolated from the environment, and human Brachybacterium infections have rarely been documented to date. To our knowledge, this is the first clinical isolation of Brachybacterium sp. as a causative pathogen of bloodstream infection.
Assuntos
Infecções por Actinomycetales/microbiologia , Bacteriemia/microbiologia , Vértebras Lombares/patologia , Micrococcaceae/isolamento & purificação , Infecções por Actinomycetales/sangue , Infecções por Actinomycetales/diagnóstico , Infecções por Actinomycetales/tratamento farmacológico , Idoso de 80 Anos ou mais , Anti-Infecciosos/uso terapêutico , Bacteriemia/sangue , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Biópsia por Agulha , Proteína C-Reativa/análise , Creatinina/análise , DNA Bacteriano/genética , Humanos , Masculino , Micrococcaceae/genética , RNA Ribossômico 16S/genéticaRESUMO
In recent years, besides the widespread occurrence of extended-spectrum ß-lactamase (ESBL)- and/or plasmid-mediated AmpC (pAmpC)-producing Enterobacteriaceae in both healthcare and community settings of humans, the third-generation cephalosporin (3GC)-resistant microbes have also been reported from companion animals worldwide. Here, we characterized ESBL- and/or pAmpC-producing Enterobacteriaceae clinical isolates from companion animals. Among the 487 clinical isolates mainly from urine of dogs and cats between May and September 2016, 104 non-repetitive isolates were resistant to the 3GC, and they consisted of 81 of 381 (21.3%) Escherichia coli, 21 of 50 (42.0%) Klebsiella pneumoniae, and 2 of 56 (3.6%) Proteus mirabilis isolates. In the 81 E. coli, the predominant bla genes were blaCTX-M-27 and blaCMY-2 (nâ¯=â¯15 each), followed by blaCTX-M-15 (nâ¯=â¯14), blaCTX-M-14 (nâ¯=â¯10), and blaCTX-M-55 (nâ¯=â¯5). In 21 K. pneumoniae, 10 bla gene types including blaCTX-M-15 (nâ¯=â¯4), blaCTX-M-2 (nâ¯=â¯4), and blaCTX-M-14 (nâ¯=â¯3) were found. The blaCTX-M-2 was identified in 2 P. mirabilis. Twenty-four of the 42 E. coli belonging to phylogroup B2 were O25b-ST131 clone, mostly associated with uropathogenic E. coli pathotype, and 22 isolates of this clone were identified as specific H30R subclone. High prevalence of the blaCTX-M-27-harboring isolates were noted among the H30R/non-Rx lineage (13/19, 68.4%) (pâ¯< â¯0.05). The genetic environment of blaCTX-M-27 of most isolates of this lineage was identical to that of human isolates, but unique flanking genetic structures were also identified. Newly emerging virulent lineage B2-non-O25b-ST1193 was also confirmed in 5 isolates. The fosA3 and/or armA genes were detected in E. coli and K. pneumoniae isolates. These data suggest that companion animals serve as a potential reservoir of antimicrobial resistant E. coli and K. pneumoniae. This also has considerable veterinary importance, since urinary tract infections are an important disease causing therapeutic challenges worldwide.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae/veterinária , Enterobacteriaceae/genética , beta-Lactamases/genética , Animais , Doenças do Gato/epidemiologia , Doenças do Gato/microbiologia , Gatos , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Enterobacteriaceae/efeitos dos fármacos , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/genética , Japão/epidemiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Animais de Estimação/microbiologia , Prevalência , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , Infecções Urinárias/microbiologiaRESUMO
PURPOSE: The decline in methicillin-resistant Staphylococcus aureus (MRSA) isolation rates has become a general observation worldwide, including Japan. We hypothesized that some genetic shift in MRSA might cause this phenomenon, and therefore we investigated the genetic profiles among MRSA clinical isolates obtained from three different epidemic phases in Japan. METHODOLOGY: A total of 353 MRSA isolates were selected from 202 medical facilities in 1990 (pre-epidemic phase), 2004 (epidemic phase) and 2016 (post-epidemic phase). Molecular typing was performed by PCR detection of 22 genes using the polymerase chain reaction (PCR)-based ORF typing (POT) system, including an additional eight genes including small genomic islets and seven toxin genes. RESULTS: Isolates with a POT1 of score 93, identified as presumed clonal complex (pCC)5-staphylococcal cassette chromosome mec (SCCmec) type II including ST5-SCCmec type II New York/Japan clone, represented the major epidemic MRSA lineage in 1990 and 2004. In 2016, however, a marked decrease in isolates with a POT1 score of 93, along with changes in the epidemiology of toxin genes carried, was noted, where the carriers of tst genes including the tst-sec combination were markedly reduced, and those possessing the seb gene alone were markedly increased. Rather, isolates with a POT1 score of 106, including pCC1 or pCC8 among the isolates with SCCmec type IV, which often links to community-associated MRSA, were predominant. Interestingly, the pCC1 and pCC8 lineages were related to sea and tst-sec carriage, respectively. CONCLUSIONS: Over time, a transition in MRSA genetic profiles from a POT1 score of 93 in 1990 and 2004 to 106 in 2014 was found in Japan.
Assuntos
Toxinas Bacterianas/genética , Epidemias , Deriva Genética , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Antibacterianos/farmacologia , Infecção Hospitalar/epidemiologia , Exotoxinas/genética , Humanos , Japão/epidemiologia , Leucocidinas/genética , Meticilina/farmacologia , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem Molecular , Fatores de Virulência/genéticaRESUMO
Despite increasing reports of skin and soft tissue infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Japan, the extent to which these strains cause nosocomial infections remains unknown, and this is especially true for bloodstream infections. In this study, we molecularly characterized MRSA isolates from Japanese blood samples. Among the 151 MRSA isolates collected from 53 medical facilities in 2011, 115 (76%) and 30 (20%) were classified as staphylococcal cassette chromosome mec (SCCmec) types II and IV, respectively, while the Panton-Valentine leukocidin (PVL) gene was detected in only two isolates. Among 66 MRSA isolates collected from Tokyo Medical University Hospital between 2012 and 2015, 43 (65%) and 20 (30%) were classifiable as SCCmec types II and IV, respectively. In 2015, highly virulent strains, such as the SCCmec type IV/PVL and SCCmec type IV/ toxic shock syndrome toxin-1 clonal types, increased in number. Therefore, the SCCmec type IV clone may cause invasive infections not only in community settings but also in healthcare settings in Japan.
Assuntos
Bacteriemia/epidemiologia , Toxinas Bacterianas/genética , Infecção Hospitalar/epidemiologia , Enterotoxinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Superantígenos/genética , Fatores de Virulência/genética , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Toxinas Bacterianas/biossíntese , Hemocultura , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Enterotoxinas/biossíntese , Exotoxinas/biossíntese , Exotoxinas/genética , Fluoroquinolonas/farmacologia , Hospitais Universitários , Humanos , Japão/epidemiologia , Leucocidinas/biossíntese , Leucocidinas/genética , Meticilina/farmacologia , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções dos Tecidos Moles/tratamento farmacológico , Infecções dos Tecidos Moles/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Superantígenos/biossíntese , Fatores de Virulência/biossíntese , beta-Lactamas/farmacologiaAssuntos
Proteínas de Bactérias/genética , Colistina/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Klebsiella pneumoniae/efeitos dos fármacos , Tigeciclina/farmacologia , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Doenças do Cão/microbiologia , Cães , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/veterinária , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Animais de Estimação , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
This study was performed to investigate the carriage rates of CTX-M-type extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli among ill companion animals in Japan. Among the 178 nonrepetitive E. coli isolates, including 131 from dogs and 47 from cats, collected between September and November 2015, 42 (23.6%) isolates from 29 dogs and 13 cats were identified as ESBL producers. The antimicrobial susceptibility, O serotype, phylogenetic group, ß-lactamase genotype, plasmid replicon type, and sequence type (ST) of each isolate were analyzed. The major ESBL types were CTX-M-14 (26.8%), CTX-M-15 (24.4%), CTX-M-27 (19.5%), and CTX-M-55 (19.5%); predominant replicon types of blaCTX-M-carrying plasmid were IncF group and IncI1-Iγ. The most prevalent STs were ST131 (n = 15, 35.7%), followed by ST38, ST10, and ST410. The 15 isolates of ST131 belonged to B2-O25. E. coli B2-O25-ST131 isolates harboring blaCTX-M-15 or blaCTX-M-27 were resistant to ceftazidime and ciprofloxacin. In particular, CTX-M-15 producers showed multidrug resistance. Our results demonstrated that the CTX-M-producing pandemic E. coli clone B2-O25-ST131 has already spread in Japanese companion animals as well. Moreover, the similarity of genotypes, serotypes, phylogenetic groups, and STs of the isolates from companion animals to those from humans suggested probable transmission of resistant bacteria between pets and humans.
Assuntos
Escherichia coli/isolamento & purificação , Escherichia coli/metabolismo , beta-Lactamases/metabolismo , Animais , Antibacterianos/farmacologia , Gatos , DNA Bacteriano/genética , Cães , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Genótipo , Japão , Testes de Sensibilidade Microbiana/métodos , Tipagem de Sequências Multilocus/métodos , FilogeniaRESUMO
A 56-year-old previously healthy man was hospitalized due to a 10-day history of neck pain and an elevated C-reactive protein level. Gram-negative spiral bacilli were isolated from his blood, and Helicobacter cinaedi was confirmed using 16S rRNA sequencing. The infectious focus was not identified by initial cervical magnetic resonance imaging (MRI); however, repeated MRI demonstrated prominent high signal intensity in the entire region of the C6-C7 vertebrae and C6/C7 disc space. Furthermore, fluorodeoxyglucose-positron emission tomography/computed tomography showed no significant uptake, other than in the C6-C7 region. The patient was successfully treated with ceftriaxone for six weeks without sequelae.
Assuntos
Vértebras Cervicais/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Hospedeiro Imunocomprometido , Osteomielite/microbiologia , Proteína C-Reativa/análise , Ceftriaxona/uso terapêutico , Diagnóstico Diferencial , Helicobacter/genética , Infecções por Helicobacter/genética , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteomielite/tratamento farmacológico , RNA Ribossômico 16S/genética , Tomografia Computadorizada por Raios XRESUMO
The Verigene Gram-positive blood culture test (BC-GP) and the Verigene Gram-negative blood culture test (BC-GN) identify representative Gram-positive bacteria, Gram-negative bacteria and their antimicrobial resistance by detecting resistance genes within 3 h. Significant benefits are anticipated due to their rapidity and accuracy, however, their clinical utility is unproven in clinical studies. We performed a clinical trial between July 2014 and December 2014 for hospitalized bacteremia patients. During the intervention period (N = 88), Verigene BC-GP and BC-GN was used along with conventional microbiological diagnostic methods, while comparing the clinical data and outcomes with those during the control period (N = 147) (UMIN registration ID: UMIN000014399). The median duration between the initiation of blood culture incubation and the reporting time of the Verigene system results was 21.7 h (IQR 18.2-26.8) and the results were found in 88% of the cases by the next day after blood cultures were obtained without discordance. The hospital-onset infection rate was higher in the control period (24% vs. 44%, p = 0.002), however, no differences were seen in co-morbidities and severity between the control and intervention periods. During the intervention period, the time of appropriate antimicrobial agents' initiation was significantly earlier than that in the control period (p = 0.001) and most cases (90%; 79/88) were treated with antimicrobial agents with in-vitro susceptibility for causative bacteria the day after the blood culture was obtained. The costs for antimicrobial agents were lower in the intervention period (3618 yen vs. 8505 yen, p = 0.001). The 30-day mortality was lower in the intervention period (3% vs. 13%, p = 0.019).
Assuntos
Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Técnicas de Diagnóstico Molecular/instrumentação , Idoso , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/microbiologia , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Feminino , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/genética , Humanos , Masculino , Análise em Microsséries/métodos , Estudos ProspectivosRESUMO
The Verigene Gram-Negative Blood Culture Nucleic Acid Test (BC-GN) is a microarray-based assay that enables rapid detection of 9 common Gram-negative bacteria and 6 resistance determinants directly from positive blood cultures. We compared the performance of BC-GN with currently used automated systems, testing 141 clinical blood cultures and 205 spiked blood cultures. For identification of BC-GN target organisms in clinical and spiked blood cultures, the BC-GN assay showed 98.5% (130/132) and 98.9% (182/184) concordance, respectively. Of 140 resistance genes positively detected in clinical and spiked blood cultures with the BC-GN test, 139 (99.3%) were confirmed by PCR, and the detection results were consistent with the resistance phenotypes observed. The BC-GN assay, thus, can potentially improve care for sepsis patients by enabling timely detection and targeted antimicrobial therapy.
Assuntos
Bacteriemia/diagnóstico , Bacteriemia/microbiologia , DNA Bacteriano/análise , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Testes de Sensibilidade Microbiana/métodos , Técnicas de Diagnóstico Molecular/métodos , Automação Laboratorial/métodos , DNA Bacteriano/genética , Bactérias Gram-Negativas/classificação , Humanos , Fatores de TempoRESUMO
A 43-year-old man was referred to our hospital for an acute-onset fever and left flank pain. He had been previously diagnosed with lymphangioma, and abdominal computed tomography showed pararenal cysts with fat stranding around the left kidney, of which infection was subsequently confirmed on magnetic resonance imaging. Gram-negative spiral bacilli were isolated from two sets of blood cultures, and Helicobacter cinaedi was identified using 16S rRNA sequencing. The patient was successfully treated with ceftriaxone therapy without recurrence. A multilocus sequence typing analysis indicated the current H. cinaedi strain differed from previous strains isolated in Japan.