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1.
JAC Antimicrob Resist ; 6(3): dlae073, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38741895

ABSTRACT

Background: The spread of transmissible plasmids with carbapenemase genes has contributed to a global increase in carbapenemase-producing Enterobacterales over the past two decades, with blaNDM and blaOXA among the most prevalent carbapenemase genes. Objectives: To characterize an Escherichia coli isolate co-carrying blaNDM-5 and blaOXA-181 (JBEHAAB-19-0176) that was isolated in the Japan Antimicrobial Resistant Bacterial Surveillance in 2019-20, and to evaluate the functional advantage of carrying both genes as opposed to only one. Methods: The whole-genome sequence of the isolate was determined using long- and short-read sequencing. Growth assay and co-culture experiments were performed for phenotypic characterization in the presence of different ß-lactam antibiotics. Results: WGS analysis showed that blaNDM-5 and blaOXA-181 were carried by the same IncX3 plasmid, pJBEHAAB-19-0176_NDM-OXA. Genetic characterization of the plasmid suggested that the plasmid emerged through the formation of a co-integrate and resolution of two typical IncX3 plasmids harbouring blaNDM-5 and blaOXA-181, which involved two recombination events at the IS3000 and IS26 sequences. When cultured in the presence of piperacillin or cefpodoxime, the growth rate of the transformant co-harbouring blaNDM-5 and blaOXA-181 was significantly higher than the transformant with only blaNDM-5. Furthermore, in co-culture where the two blaNDM-5-harbouring transformants were allowed to compete directly, the strain additionally harbouring blaOXA-181 showed a marked growth advantage. Conclusions: The additional carriage of blaOXA-181 confers a selective advantage to bacteria in the presence of piperacillin and cefpodoxime. These findings may explain the current epidemiology of carbapenemase-producing Enterobacterales, in which bacteria carrying both blaNDM-5 and blaOXA-48-like genes have emerged independently worldwide.

2.
J Glob Antimicrob Resist ; 38: 12-20, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38789082

ABSTRACT

OBJECTIVES: The treatment options available for infections caused by multidrug-resistant Gram-negative pathogens are often limited. Cefiderocol (CFDC) is a novel siderophore cephalosporin that exhibits activity against these pathogens. Several studies have reported the in vitro activity of CFDC against isolates from Europe, the United States, and China, but the activity against carbapenem-resistant bacteria with IMP-type carbapenemase has not been extensively studied. We, therefore, studied the in vitro activities of CFDC against carbapenem-resistant bacteria with available genomic backgrounds based on whole-genome sequencing (WGS) in Japan, where the IMP-type is the predominant carbapenemase produced by Gram-negative rods. METHODS: We selected 603 isolates (528 Enterobacterales, 18 Pseudomonas aeruginosa, and 57 Acinetobacter spp.) from a collection of Gram-negative clinical isolates collected during a Japan Antimicrobial Resistance Bacterial Surveillance program and evaluated the antimicrobial activities of CFDC, ceftolozane/tazobactam (CTLZ/TAZ), imipenem-relebactam (IPM/REL), and ceftazidime/avibactam (CAZ/AVI) against carbapenemase-producing Enterobacterales, carbapenemase-non-producing meropenem-non-susceptible Enterobacterales, and carbapenemase-producing nonfermentative bacteria. RESULTS: Among these, 97.7% of carbapenemase-producing Enterobacterales (99.2% of IMP-type carbapenemase-producing Enterobacterales), 100% of carbapenemase-producing P. aeruginosa, and 91.2% of carbapenemase-producing Acinetobacter spp. were susceptible to CFDC, showing better antimicrobial activity than the other antimicrobial agents evaluated in this study. CFDC was highly effective against class A-, B-, and D ß-lactamase-harbouring isolates when compared to the other antimicrobial agents. In addition, the relationship between CFDC resistance and three genetic factors involved in resistance was discussed. CONCLUSIONS: This is the first large-scale study to systematically demonstrate the efficacy of CFDC against IMP-type carbapenemase-producing strains with known genomic backgrounds.

3.
Antimicrob Agents Chemother ; 68(5): e0166923, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38564665

ABSTRACT

Japan is a country with an approximate 10% prevalence rate of carbapenem-resistant Pseudomonas aeruginosa (CRPA). Currently, a comprehensive overview of the genotype and phenotype patterns of CRPA in Japan is lacking. Herein, we conducted genome sequencing and quantitative antimicrobial susceptibility testing for 382 meropenem-resistant CRPA isolates that were collected from 78 hospitals across Japan from 2019 to 2020. CRPA exhibited susceptibility rates of 52.9%, 26.4%, and 88.0% against piperacillin-tazobactam, ciprofloxacin, and amikacin, respectively, whereas 27.7% of CRPA isolates was classified as difficult-to-treat resistance P. aeruginosa. Of the 148 sequence types detected, ST274 (9.7%) was predominant, followed by ST235 (7.6%). The proportion of urine isolates in ST235 was higher than that in other STs (P = 0.0056, χ2 test). Only 4.1% of CRPA isolates carried the carbapenemase genes: blaGES (2) and blaIMP (13). One ST235 isolate carried the novel blaIMP variant blaIMP-98 in the chromosome. Regarding chromosomal mutations, 87.1% of CRPA isolates possessed inactivating or other resistance mutations in oprD, and 28.8% showed mutations in the regulatory genes (mexR, nalC, and nalD) for the MexAB-OprM efflux pump. Additionally, 4.7% of CRPA isolates carried a resistance mutation in the PBP3-encoding gene ftsI. The findings from this study and other surveillance studies collectively demonstrate that CRPA exhibits marked genetic diversity and that its multidrug resistance in Japan is less prevailed than in other regions. This study contributes a valuable data set that addresses a gap in genotype/phenotype information regarding CRPA in the Asia-Pacific region, where the epidemiological background markedly differs between regions.


Subject(s)
Anti-Bacterial Agents , Bacterial Proteins , Carbapenems , Microbial Sensitivity Tests , Pseudomonas Infections , Pseudomonas aeruginosa , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/isolation & purification , Japan/epidemiology , Carbapenems/pharmacology , Anti-Bacterial Agents/pharmacology , Humans , Bacterial Proteins/genetics , Pseudomonas Infections/microbiology , Pseudomonas Infections/epidemiology , Pseudomonas Infections/drug therapy , beta-Lactamases/genetics , Genome, Bacterial/genetics , Piperacillin, Tazobactam Drug Combination/therapeutic use , Piperacillin, Tazobactam Drug Combination/pharmacology , Whole Genome Sequencing , Meropenem/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Amikacin/pharmacology
5.
J Antimicrob Chemother ; 79(2): 312-319, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38084874

ABSTRACT

BACKGROUND: Antimicrobial use (AMU) in primary care is a contributing factor to the emergence of antimicrobial-resistant bacteria. We assessed the potential effects of AMU on the prevalence of a combination of resistance phenotypes in bacteraemic Escherichia coli in outpatient care settings between primary care facilities ('clinics') and hospitals. METHODS: Population-weighted total AMU calculated from the national database was expressed as DDDs per 1000 inhabitants per day (DID). National data for all routine microbiological test results were exported from the databases of a major commercial clinical laboratory, including 16 484 clinics, and the Japan Nosocomial Infections Surveillance, including 1947 hospitals. AMU and the prevalence of combinations of resistance phenotypes in bacteraemic E. coli isolates were compared between clinics and hospitals. RESULTS: The five most common bacteria isolated from patients with bacteraemia were the same in clinics, outpatient settings and inpatient settings in hospitals, with E. coli as the most frequent. Oral third-generation cephalosporins and fluoroquinolones were the top two AMU outpatient drugs, except for macrolides, and resulted in at least three times higher AMU in clinics than in hospitals. The percentage of E. coli isolates resistant to both drugs in clinics (18.7%) was 5.6% higher than that in hospitals (13.1%) (P < 10-8). CONCLUSIONS: Significant AMU, specifically of oral third-generation cephalosporins and fluoroquinolones, in clinics is associated with a higher prevalence of E. coli isolates resistant to both drugs. This study provides a basis for national interventions to reduce inappropriate AMU in primary care settings.


Subject(s)
Anti-Infective Agents , Bacteremia , Humans , Escherichia coli , Japan/epidemiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Infective Agents/pharmacology , Fluoroquinolones/pharmacology , Bacteremia/drug therapy , Bacteremia/epidemiology , Cephalosporins/pharmacology , Primary Health Care , Drug Resistance, Bacterial
6.
Nat Commun ; 14(1): 8046, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38052776

ABSTRACT

Antimicrobial resistance is a global health concern; Enterobacterales resistant to third-generation cephalosporins (3GCs) and carbapenems are of the highest priority. Here, we conducted genome sequencing and standardized quantitative antimicrobial susceptibility testing of 4,195 isolates of Escherichia coli and Klebsiella pneumoniae resistant to 3GCs and Enterobacterales with reduced meropenem susceptibility collected across Japan. Our analyses provided a complete classification of 3GC resistance mechanisms. Analyses with complete reference plasmids revealed that among the blaCTX-M extended-spectrum ß-lactamase genes, blaCTX-M-8 was typically encoded in highly similar plasmids. The two major AmpC ß-lactamase genes were blaCMY-2 and blaDHA-1. Long-read sequencing of representative plasmids revealed that approximately 60% and 40% of blaCMY-2 and blaDHA-1 were encoded by such plasmids, respectively. Our analyses identified strains positive for carbapenemase genes but phenotypically susceptible to carbapenems and undetectable by standard antimicrobial susceptibility testing. Systematic long-read sequencing enabled reconstruction of 183 complete plasmid sequences encoding three major carbapenemase genes and elucidation of their geographical distribution stratified by replicon types and species carrying the plasmids and potential plasmid transfer events. Overall, we provide a blueprint for a national genomic surveillance study that integrates standardized quantitative antimicrobial susceptibility testing and characterizes resistance determinants.


Subject(s)
Anti-Bacterial Agents , Drug Resistance, Bacterial , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Escherichia coli , Plasmids/genetics , Genomics , Carbapenems/pharmacology , Microbial Sensitivity Tests
7.
Microbiol Spectr ; 11(6): e0216723, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-37855603

ABSTRACT

IMPORTANCE: IncX3 plasmids harboring bla NDM-5 play a major role in the spread of carbapenem resistance in Asia, particularly in China, in clinical and environmental settings. In this study, we present that Enterobacterales isolates carrying IncX3 plasmids harboring bla NDM-5 have been disseminated in Japan, where their identification was previously rare. In addition, bla NDM-16b, a single-nucleotide variant of bla NDM-5, was found to be carried by an identical IncX3 plasmid. A comparative sequence analysis revealed that the bla NDM-16b gene emerged from a single nucleotide substitution on an IncX3 plasmid harboring bla NDM-5. The bla NDM-16b gene did not confer elevated carbapenem resistance compared to bla NDM-5 in our assay using transformants carrying the plasmid harboring either of these genes, although the A233V substitution was reported to confer stability to the enzyme in ion-depleted conditions. Nevertheless, vigilance regarding the emergence of novel variants is required.


Subject(s)
Carbapenems , beta-Lactamases , beta-Lactamases/genetics , Japan , Plasmids/genetics , Carbapenems/pharmacology , Nucleotides
8.
Antimicrob Agents Chemother ; 66(6): e0012522, 2022 06 21.
Article in English | MEDLINE | ID: mdl-35647649

ABSTRACT

Faropenem (FRPM) is active against extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales, but evidence for its efficacy is lacking. This study determined the correlation between the susceptibility by disk diffusion method and the MIC of FRPM for third-generation cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae, and the effectiveness of FRPM for the treatment of urinary tract infection (UTI) caused by these two bacteria in a retrospective cohort analysis. Of the 48 third-generation cephalosporin-resistant clinical isolates tested, 44 isolates produced ESBL, and 8 isolates produced AmpC, including 4 isolates produced both ESBL and AmpC. Thirty-seven isolates had an FRPM MIC of ≤1 mg/L, and seven had an FRPM MIC of 2 mg/L. An FRPM MIC of >2 mg/L was observed with four isolates. In a retrospective cohort analysis, 63 patients with UTI treated with FRPM were identified. All isolates of ESBL-producing E. coli (n = 54) and K. pneumoniae (n = 9) treated with FRPM showed disk diffusion zone diameters larger than 16.0 mm (estimated MIC, 2.2 mg/L). All patients completed the scheduled treatment courses with FRPM, but 28- and 90-day relapses happened in 10 patients (16%) and 16 patients (25%), respectively. No significant risk factors for the 28- and 90-day relapses were found. FRPM can be used according to disk diffusion susceptibility testing in UTI. Further investigations are necessary to assess the clinical breakpoint of FRPM for ESBL-producing Enterobacterales and the candidates most likely to benefit from using FRPM.


Subject(s)
Escherichia coli Infections , Urinary Tract Infections , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cephalosporins/pharmacology , Cephalosporins/therapeutic use , Escherichia coli , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Humans , Klebsiella pneumoniae , Microbial Sensitivity Tests , Recurrence , Retrospective Studies , Treatment Outcome , Urinary Tract Infections/drug therapy , Urinary Tract Infections/microbiology , beta-Lactamases/therapeutic use , beta-Lactams
10.
Infect Drug Resist ; 14: 3357-3362, 2021.
Article in English | MEDLINE | ID: mdl-34471362

ABSTRACT

INTRODUCTION: Extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) reportedly accounts for >20% of E. coli infections and 2.0% of infective endocarditis cases. Nonetheless, there is a global paucity of reports on infective endocarditis caused by ESBL-EC. CASE: An 83-year-old Japanese man who underwent mitral annuloplasty for mitral valve prolapse 5 years ago developed a fever of 38.5°C. The patient was hospitalized the first time for pyelonephritis and bacteremia due to ESBL-EC and treated successfully with the antimicrobial meropenem for 14 days. Two days after discharge, however, the patient was re-admitted with bacteremia due to ESBL-EC. He was treated successfully with the antimicrobial cefmetazole for 14 days. The patient was admitted to our institution for a third time due to bacteremia again, a day after discharge following meropenem antibiotic therapy. Transesophageal echocardiography showed vegetation in the anterior mitral valve annulus. Magnetic resonance imaging of the head showed septic cerebral embolism. The patient was diagnosed with infective endocarditis due to ESBL-EC and underwent mitral valve replacement. After 6 weeks of antibiotic therapy with meropenem and tobramycin, the patient recovered completely. The causative E. coli strain MS6396 was identified as the E. coli clone ST131 by multilocus sequence typing and confirmed the presence of bla CTX-M-27 ESBL gene. CONCLUSION: Only six cases of infective endocarditis associated with ESBL-EC have been reported in the past. Moreover, this is the first report of a patient with infective endocarditis bacteriologically or genetically analyzed for ESBL-EC. In future, factors that may cause infective endocarditis in ESBL-EC infections may be clarified through more thorough bacteriological/genetic analyses of ESBL-EC.

11.
J Infect Chemother ; 25(9): 657-668, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31196772

ABSTRACT

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2014. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January 2014 and April 2015 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 1534 strains (335 Staphylococcus aureus, 264 Streptococcus pneumoniae, 29 Streptococcus pyogenes, 281 Haemophilus influenzae, 164 Moraxella catarrhalis, 207 Klebsiella pneumoniae, and 254 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 43.6%, and those of penicillin-susceptible S. pneumoniae was 100%. Among H. influenzae, 8.2% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 49.1% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 9.2% and 0.4%, respectively.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Epidemiological Monitoring , Respiratory Tract Infections/prevention & control , Antimicrobial Stewardship , Haemophilus influenzae/drug effects , Humans , Japan/epidemiology , Klebsiella pneumoniae/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Moraxella catarrhalis/drug effects , Pseudomonas aeruginosa/drug effects , Respiratory Tract Infections/microbiology , Streptococcus pneumoniae/drug effects , Streptococcus pyogenes/drug effects
12.
J Infect Chemother ; 23(9): 587-597, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28669567

ABSTRACT

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 37.2% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacteria/isolation & purification , Respiratory System/microbiology , Respiratory Tract Infections/microbiology , Drug Resistance, Bacterial , Haemophilus influenzae/drug effects , Haemophilus influenzae/isolation & purification , Humans , Japan , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Microbial Sensitivity Tests , Moraxella catarrhalis/drug effects , Moraxella catarrhalis/isolation & purification , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Public Health Surveillance , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/isolation & purification , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/isolation & purification , beta-Lactamases/analysis
13.
J Med Microbiol ; 66(2): 203-212, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27902395

ABSTRACT

PURPOSE: We investigated the expression levels of virulence factors (ompA, omp33-36 and carO) in five clinical isolates and in a standard ATCC 19606 strain of Acinetobacter baumannii to determine their effect on the virulence characteristics of the isolates. METHODOLOGY: The mRNA levels of omps and proinflammatory cytokines were analyzed by quantitative real-time PCR. For adherence assay, after human lung epithelial cells (A549) were co-cultured with A. baumannii at 37 °C for 2 h, the cell-adherent bacteria was counted. Pearson correlation analysis was used to compare the omps mRNA levels, the proinflammatory cytokines and the number of adherent bacteria. RESULTS: The mRNA levels of ompA in the clinical isolates were higher and similar compared with those in ATCC 19606, whereas the mRNA levels of omp33-36 in the clinical isolates were lower and similar compared with those in ATCC 19606. The mRNA levels of carO in the clinical isolates were significantly higher than those in ATCC 19606. The number of cell-adherent clinical isolates was higher than that of cell-adherent ATCC 19606. Furthermore, the number of cell-adherent clinical isolates was positively and significantly correlated with ompA mRNA level. The mRNA levels of TNF-α, IL-6 and IL-8 in A549 cells co-cultured with the clinical isolates were lower than those in A549 cells co-cultured with ATCC 19606. Moreover, the mRNA levels of TNF-α, IL-6 and IL-8 were negatively and significantly correlated with those of carO in the isolates. CONCLUSION: These results provide insights into the renewed virulence characteristics of A. baumannii clinical isolates that depend on cell adherence capacity and the expression level of omp mRNAs.


Subject(s)
Acinetobacter baumannii/pathogenicity , Bacterial Outer Membrane Proteins/metabolism , Porins/metabolism , Virulence Factors/metabolism , A549 Cells , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Bacterial Adhesion , Bacterial Outer Membrane Proteins/genetics , Coculture Techniques , Cross Infection/genetics , Cross Infection/microbiology , Humans , Interleukin-6/metabolism , Interleukin-8/metabolism , Porins/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Tumor Necrosis Factor-alpha/metabolism , Virulence Factors/genetics
14.
J Infect Chemother ; 21(7): 512-5, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25862195

ABSTRACT

Acinetobacter baumannii is a Gram-negative bacterial agent involved in nosocomial infections. In this five-year retrospective study, phylogenetic relationships among carbapenem-resistant A. baumannii strains that were isolated at Teikyo University Hospital in Tokyo metropolis, Japan, were explored. A panel of 72 carbapenem-resistant A. baumannii strains that isolated from January 2006 until August 2010 was studied. Next-Generation sequencing (NGS) was employed to perform large-scale genotyping of these isolates. They were separated, according to the time of isolation, into two genetically distinct groups, one correspondent to strains of the outbreak reported to local public health department in 2010 and the other contained strains from earlier isolations, suggesting different origins of the isolates. Moreover, taxa in each group showed two main clustering patterns. Multilocus sequence typing (MLST) study on 8 isolates from the last outbreak showed that they were from one sequence type, 92, displaying less discriminatory power comparing to large-sequence typing. The clonal lineage profiles produced in this retrospective study will be used as a reference database to compare future isolations of A. baumannii. This study demonstrates the power of NGS in conducting epidemiological researches, allowing a high resolution genotyping.


Subject(s)
Acinetobacter Infections/microbiology , Acinetobacter baumannii/genetics , Genotyping Techniques/methods , Molecular Typing/methods , Sequence Analysis, DNA/methods , Acinetobacter baumannii/classification , Cross Infection/microbiology , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Disease Outbreaks , Drug Resistance, Bacterial , Genotype , Humans , Retrospective Studies , Tokyo
15.
J Infect Chemother ; 21(6): 410-20, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25817352

ABSTRACT

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and -resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be ß-lactamase-non-producing ABPC-resistant and 11.0% to be ß-lactamase-producing ABPC-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteria/drug effects , Bacterial Infections/drug therapy , Drug Resistance, Bacterial/drug effects , Respiratory Tract Infections/drug therapy , Respiratory Tract Infections/microbiology , Communicable Diseases/drug therapy , Communicable Diseases/microbiology , Humans , Japan , Microbial Sensitivity Tests
17.
J Infect Chemother ; 19(3): 517-23, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23073648

ABSTRACT

We present here three cases in which morphological changes and/or a decreased number of Streptococcus pneumoniae or Moraxella catarrhalis could be observed in gram-stained sputum obtained just after the first administration of an antimicrobial agent. Case 1 was a 53-year-old man with pneumonia caused by gram-positive diplococcus, identified as S. pneumoniae, who was administered 2 g of ampicillin over a period of 1 h. Gram-stained sputum showed smaller or gram-negative pneumococci at the completion of administration of the agent, a decreased number of cocci at 1 h after administration, and almost no cocci at 12 h after the completion of administration. Case 2 was a 72-year-old woman with pneumonia caused by diplococcus, identified as S. pneumoniae, who was administered 2 g of ampicillin over a period of 1 h. Gram-stained sputum showed weakly stained, small cocci at the completion of administration of the agent and few cocci at 1 h after the completion of administration. Case 3 was a 58-year-old woman with pneumonia caused by a gram-negative diplococcus, identified as Moraxella catarrhalis, who was administered 1 g of cefotaxime over a period of 30 min. Gram-stained sputum showed few extracellular cocci and some intracellular cocci inside neutrophils 1 h after administration and no cocci 2 h after the completion of administration. These three cases showed that gram-stained sputum obtained just after and/or 1 h after administration of the first antimicrobial agent were suitable as the quickest therapeutic indicator of the effectiveness of empiric therapy, with the effectiveness of the agent being shown much earlier than with markers such as the white blood cell count and C-reactive protein level.


Subject(s)
Community-Acquired Infections/microbiology , Gentian Violet/chemistry , Moraxella catarrhalis/isolation & purification , Phenazines/chemistry , Pneumonia, Bacterial/microbiology , Sputum/microbiology , Streptococcus pneumoniae/isolation & purification , Aged , Community-Acquired Infections/diagnosis , Community-Acquired Infections/drug therapy , Female , Humans , Male , Middle Aged , Moraxella catarrhalis/classification , Moraxellaceae Infections/diagnosis , Moraxellaceae Infections/drug therapy , Moraxellaceae Infections/microbiology , Pneumonia, Bacterial/diagnosis , Pneumonia, Bacterial/drug therapy , Pneumonia, Pneumococcal/diagnosis , Pneumonia, Pneumococcal/drug therapy , Pneumonia, Pneumococcal/microbiology , Streptococcus pneumoniae/classification
18.
Intern Med ; 51(22): 3185-8, 2012.
Article in English | MEDLINE | ID: mdl-23154730

ABSTRACT

A 31-year-old woman who had developed systemic lupus erythematosus at 17 years of age was admitted to the hospital for suspected cellulitis in the lower extremities. A blood culture performed upon admission to the hospital detected Helicobacter cinaedi (H. cinaedi), which was also isolated in blood and fecal cultures obtained on the 42nd hospital day. Bacterial translocation of H. cinaedi present in the intestines may have led to the development of recurrent bacteremia and cellulitis. In cases such as this, appropriate antibiotics therapy might be needed for more than one month. Moreover, H. cinaedi, a cause of emerging infections, requires a long period of time to grow; therefore it is important to extend the culture duration when the presence of this bacterium is suspected.


Subject(s)
Bacteremia/complications , Cellulitis/complications , Helicobacter Infections/complications , Lupus Erythematosus, Systemic/complications , Adult , Anti-Bacterial Agents/therapeutic use , Aztreonam/therapeutic use , Bacteremia/drug therapy , Bacteremia/microbiology , Cellulitis/drug therapy , Cellulitis/microbiology , Communicable Diseases, Emerging/complications , Communicable Diseases, Emerging/drug therapy , Communicable Diseases, Emerging/microbiology , Female , Helicobacter/isolation & purification , Helicobacter Infections/drug therapy , Helicobacter Infections/microbiology , Humans , Recurrence
19.
J Infect Chemother ; 18(6): 931-6, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22476652

ABSTRACT

A 32-year-old man was admitted to our hospital because of fever, headache, and loss of consciousness. Four days before admission, he had had difficulty speaking. On the day of admission, his colleague had found him to be unconscious and lying on his back. He was admitted to our hospital. The temperature at the eardrum was 35.2°C. Neurologic evaluation was negative. Computed tomography (CT) scan of the brain showed slight ventricular enlargement bilaterally. An X-ray film of the chest showed no abnormality. On the second hospital day, neck stiffness was noted. The cerebrospinal fluid (CSF) contained 870 white cells/µl, most of which were neutrophils; the glucose level in the CSF was 10 mg/dl, and the protein level was 140 mg/dl. Stained smears of the CSF, including Gram staining and India-ink preparations, disclosed no microorganisms. Capsular antigen tests for several bacteria were negative. Antimicrobial agents were started. However, by changing the microscope focus slightly while viewing Gram stains of the CSF, we could see brightened and Gram-positive bacilli that had been phagocytosed by neutrophils. This finding suggested the presence of Mycobacterium tuberculosis. Ziehl-Neelsen staining of the CSF and gastric juice revealed anti-acid bacilli. Polymerase chain reaction for M. tuberculosis in the gastric juice was positive. This case showed that Gram staining could be useful as an initial adjunct for the diagnosis of tuberculous meningitis, particularly when the CSF shows predominantly neutrocytic pleocytosis, but no other evidence of bacterial meningitis.


Subject(s)
Bacterial Typing Techniques/methods , Gentian Violet/chemistry , Mycobacterium tuberculosis/isolation & purification , Phenazines/chemistry , Tuberculosis, Meningeal/microbiology , Adult , Antitubercular Agents/therapeutic use , Humans , Male , Staining and Labeling/methods , Tuberculosis, Meningeal/cerebrospinal fluid , Tuberculosis, Meningeal/diagnosis , Tuberculosis, Meningeal/drug therapy
20.
J Infect Chemother ; 17(4): 510-23, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21409533

ABSTRACT

For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ß-lactams (four penicillins, three penicillins in combination with ß-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), three aminoglycosides, four macrolides (including a ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). The incidence of methicillin-resistant S. aureus (MRSA) was as high as 59.8%, and those of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) were 35.5 and 11.8%, respectively. Among H. influenzae, 13.9% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 26.7% to be ß-lactamase-non-producing ABPC-resistant (BLNAR), and 5.3% to be ß-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5%) of ß-lactamase-producing strains was suspected in Moraxella catarrhalis isolates. Four (3.2%) extended-spectrum ß-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5%) of P. aeruginosa were found to be metallo ß-lactamase-producing strains, including three (1.9%) suspected multidrug-resistant strains showing resistance to imipenem, amikacin, and ciprofloxacin. Continual national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacterial Infections/microbiology , Respiratory Tract Infections/microbiology , Adult , Bacteria/isolation & purification , Bacterial Infections/epidemiology , Drug Resistance, Bacterial , Haemophilus influenzae/drug effects , Humans , Inhibitory Concentration 50 , Japan/epidemiology , Klebsiella pneumoniae/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Moraxella catarrhalis/drug effects , Population Surveillance , Pseudomonas aeruginosa/drug effects , Respiratory Tract Infections/epidemiology , Streptococcus pneumoniae/drug effects
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