At the time when owing to COVID-19 pandemic, the public is more interested in infectious diseases and pathogens than in any other period, a book titled “The New Microbiology: From Microbiomes to CRISPR” by the renowned microbiologist Pascale Cossart was translated and published by our colleague. In this book, the author describes important discoveries and new conceptual advances in the field of microbiology over the past century. The author emphasizes that bacteria form a microbiome and lead a social life and explains the impact and importance of the microbiome on human health and ecosystem. Further, the discovery of ‘CRISPR,’ which led to the era of genome editing and gene therapy, has been described in details. This book will dramatically change our perspective regarding all living things, including bacteria, plants, animals, and even insects, as well as our eating habits and daily life, based on the new understanding of microorganisms. I recommend reading this book as I am sure that it will broaden the perspectives of both clinical microbiologists and health care workers.

BACKGROUND: We aimed to validate a pilot study of photodiagnosis using near infrared (NIR) transillumination and assess the clinical efficacy of hypericin-mediated photodynamic therapy (HYP-PDT) in a rabbit laryngeal cancer model in order to develop a novel therapeutic modality with complete remission and preservation of the functional organ. METHODS: (1) In vitro study: VX tumor cells were subcultured and subjected to HYP-PDT. (2) In vivo study: A laryngeal cancer model was developed in which 12 rabbits were inoculated with a VX tumor suspension in the submucosal area of the left vocal fold using a transoral approach. All rabbits underwent NIR transillumination using light with a wavelength of 780 nm. The survival periods of the three treatment groups (6 rabbits in Group A: HYP-PDT, 3 each in Groups B and C: laser irradiation or HYP administration only) were analyzed. RESULTS: The higher the HYP concentration, the lower the VX cell viability in response to HYP-PDT using 590 nm LED. Following HYP-PDT, small tumors in Group A-1 rabbits healed completely and the animals demonstrated a long survival period, and larger tumors in Group A-2 healed partially with a survival period that extended over 3 weeks after inoculation. The survival of Groups B and C were not different over the first 3 weeks of the study, and were shorter than in Group A. CONCLUSION We found HYP-PDT could be a curative therapy for early-stage cancers that may also preserve organ function, and may inhibit tumor progression and metastasis during advanced stages of laryngeal cancer.

BACKGROUND: Nasopharyngeal aspirate (NPA) is known as the best specimen for accurate diagnosis of viral respiratory infections in pediatric patients, but the procedure is very annoying. Recently introduced flocked swabs have been reported to be easy to obtain a good quality specimen and comfortable to patients. The purpose of this study was to compare the sensitivities between NPA and nasopharyngeal flocked swabs (NPFS) for detection of respiratory viruses in children. METHODS: For this study, 111 hospitalized children with acute respiratory tract infections were recruited. NPA and NPFS were performed in parallel from each patient. NPFS were always collected after NPA. Specimens were tested for six common respiratory viruses in triplicate using indirect immunofluorescence (IIF), viral cultures, and multiplex reverse transcription PCR (RT-PCR). RESULTS: The proportion of specimens inadequate for IIF was higher in NPA (23.4%) than NPFS (5.4%). According to the consensus positive, the positive rates of NPFS were higher than those of NPA when using IIF (45.7% and 30.6%, P=0.048) and culture (38.7% and 27.9%, P=0.004). However, the false-positive rates of NPFS were higher than those of NPA when using IIF (12.4% and 1.2%, P=0.004). The positive rates of NPFS and those of NPA were not different in multiplex RT-PCR (67.6% and 55.9%, P=0.055). CONCLUSION: The higher sensitivity of IIF for NPFS specimens and of culture for respiratory viruses and the similar sensitivities in multiplex PCR could make them an alternative to NPA samples, especially in physician clinics or emergency rooms.
Child ; Child, Hospitalized ; Consensus ; Diagnosis ; Emergency Service, Hospital ; Fluorescent Antibody Technique, Indirect ; Humans ; Multiplex Polymerase Chain Reaction ; Nasopharynx ; Polymerase Chain Reaction ; Respiratory Tract Infections ; Reverse Transcription ; Specimen Handling

With increase of multi-drug resistant Escherichia coli in community-acquired urinary tract infections (CA-UTI), other treatment option with a therapeutic efficacy and a low antibiotic selective pressure is necessary. In this study, we evaluated in vitro susceptibility of E. coli isolates from CA-UTI to fosfomycin (FM), nitrofurantoin (NI), temocillin (TMO) as well as trimethoprim-sulfamethoxazole (SMX), ciprofloxacin (CIP) and cefepime (FEP). The minimal inhibitory concentrations were determined by E-test or agar dilution method according to the Clinical and Laboratory Standards Institute guidelines, using 346 E. coli collected in 12 Korean hospitals from March 2010 to February 2011. FM, NI and TMO showed an excellent susceptibility profile; FM 100% (346/346), TMO 96.8% (335/346), and NI 99.4% (344/346). Conversely, resistance rates of CIP and SMX were 22% (76/346) and 29.2% (101/349), respectively. FEP still retained an activity of 98.5%. In Korea, NI and TMO in addition to FM are a good therapeutic option for uncomplicated CA-UTI, especially for lower UTI.
Anti-Bacterial Agents/*administration & dosage ; Cell Survival/*drug effects ; Cephalosporins/administration & dosage ; Ciprofloxacin/administration & dosage ; Community-Acquired Infections/drug therapy/*microbiology ; Dose-Response Relationship, Drug ; Drug Combinations ; Drug Resistance, Bacterial/drug effects ; Escherichia coli/*drug effects ; Escherichia coli Infections/drug therapy/*microbiology ; Fosfomycin/administration & dosage ; Humans ; Nitrofurantoin/administration & dosage ; Penicillins/administration & dosage ; Republic of Korea ; Sulfadoxine/administration & dosage ; Treatment Outcome ; Trimethoprim/administration & dosage ; Urinary Tract Infections/diagnosis/*microbiology

With increase of multi-drug resistant Escherichia coli in community-acquired urinary tract infections (CA-UTI), other treatment option with a therapeutic efficacy and a low antibiotic selective pressure is necessary. In this study, we evaluated in vitro susceptibility of E. coli isolates from CA-UTI to fosfomycin (FM), nitrofurantoin (NI), temocillin (TMO) as well as trimethoprim-sulfamethoxazole (SMX), ciprofloxacin (CIP) and cefepime (FEP). The minimal inhibitory concentrations were determined by E-test or agar dilution method according to the Clinical and Laboratory Standards Institute guidelines, using 346 E. coli collected in 12 Korean hospitals from March 2010 to February 2011. FM, NI and TMO showed an excellent susceptibility profile; FM 100% (346/346), TMO 96.8% (335/346), and NI 99.4% (344/346). Conversely, resistance rates of CIP and SMX were 22% (76/346) and 29.2% (101/349), respectively. FEP still retained an activity of 98.5%. In Korea, NI and TMO in addition to FM are a good therapeutic option for uncomplicated CA-UTI, especially for lower UTI.
Anti-Bacterial Agents/*administration & dosage ; Cell Survival/*drug effects ; Cephalosporins/administration & dosage ; Ciprofloxacin/administration & dosage ; Community-Acquired Infections/drug therapy/*microbiology ; Dose-Response Relationship, Drug ; Drug Combinations ; Drug Resistance, Bacterial/drug effects ; Escherichia coli/*drug effects ; Escherichia coli Infections/drug therapy/*microbiology ; Fosfomycin/administration & dosage ; Humans ; Nitrofurantoin/administration & dosage ; Penicillins/administration & dosage ; Republic of Korea ; Sulfadoxine/administration & dosage ; Treatment Outcome ; Trimethoprim/administration & dosage ; Urinary Tract Infections/diagnosis/*microbiology

BACKGROUND: Antimicrobial susceptibility testing (AST) of Clostridium difficile is increasingly important because of the rise in resistant strains. The standard medium for the AST of C. difficile is supplemented Brucella agar (sBA), but we found that the growth of C. difficile on sBA was not optimal. Because active growth is critical for reliable AST, we developed a new, modified C. difficile (mCD) agar. C. difficile grew better on mCD agar than on sBA. METHODS: C. difficile isolates were collected from patients with healthcare-associated diarrhea. sBA medium was prepared according to the CLSI guidelines. Homemade mCD agar containing taurocholate, L-cysteine hydrochloride, and 7% horse blood was used. For 171 C. difficile isolates, we compared the agar dilution AST results from mCD agar with those from sBA. RESULTS: No significant differences were observed in the 50% minimal inhibitory concentration (MIC50) and 90% minimal inhibitory concentration (MIC90) of clindamycin (CLI), metronidazole (MTZ), moxifloxacin (MXF), piperacillin-tazobactam (PTZ), and rifaximin (RIX), but the values for vancomycin (VAN) were two-fold higher on mCD agar than on sBA. The MICs of CLI, MXF, and RIX were in 100% agreement within two-fold dilutions, but for MTZ, VAN, and PTZ, 13.7%, 0.6%, and 3.1% of the isolates, respectively, were outside the acceptable range. CONCLUSIONS: The MIC ranges, MIC50 and MIC90, were acceptable when AST was performed on mCD agar. Thus, mCD agar could be used as a substitute medium for the AST of C. difficile.
Anti-Infective Agents/*pharmacology ; Clostridium Infections/microbiology ; Clostridium difficile/*drug effects/isolation & purification ; Diarrhea/*microbiology ; Humans ; Microbial Sensitivity Tests/*methods

PURPOSE: This study investigated the clinical presentations of symptomatic Clostridium difficile infection (CDI) in children. METHODS: We reviewed the medical records of 43 children aged <20 years who showed either positive C. difficile culture or C. difficile toxin test results between June 2010 and April 2014. RESULTS: Of the 43 patients (mean age 6.7 years), 22 were boys. Sixteen patients (37.2%) showed both positive C. difficile culture and toxin test results. Seventeen out of 43 children (39.5%) had preexisting gastrointestinal diseases, and 26 children had other medical conditions that were risk factors for CDI. Twenty-eight children had a history of antibiotic treatment for >3 days, and the most frequently prescribed antibiotic was amoxicillin-clavulanate (35.7%). Twenty-eight patients were diagnosed with CDI despite taking probiotic supplements, most commonly Lactobacillus acidophilus (53.6%). The most common symptom was diarrhea (72.1%) at the time CDI was diagnosed. C. difficile was eradicated in 11 patients (25.6%) after treatment with oral metronidazole for 10-14 days, and in the two patients (4.6%) who required two courses of oral metronidazole. Sixteen patients (37.2%) showed clinical improvement without any treatment. CONCLUSION: This study showed the various clinical characteristics of CDI in children and that preexisting clinical conditions favored the development of CDI. In addition, CDI was found to occur in a number of patients even after probiotic prophylaxis given in conjunction with antibiotic therapy.
Child* ; Clostridium difficile* ; Diarrhea ; Gastrointestinal Diseases ; Humans ; Lactobacillus acidophilus ; Medical Records ; Metronidazole ; Probiotics* ; Risk Factors

BACKGROUND: Binary toxin-producing Clostridium difficile infections (CDI) are known to be more severe and to cause higher case fatality rates than those by binary toxin-negative isolates. There has been few data of binary toxin-producing CDI in Korea. Objective of the study is to characterize clinical and microbiological trait of CDI cause by binary-toxin producing isolates in Korea. MATERIALS AND METHODS: From September 2008 through January 2010, clinical characteristics, medication history and treatment outcome of all the CDI patients were collected prospectively. Toxin characterization, PCR ribotyping and antibiotic susceptibility were performed with the stool isolates of C. difficile. RESULTS: During the period, CDI caused by 11binary toxin-producing isolates and 105 toxin A & toxin B-positive binary toxin-negative isolates were identified. Comparing the disease severity and clinical findings between two groups, leukocytosis and mucoid stool were more frequently observed in patients with binary toxin-positive isolates (OR: 5.2, 95% CI: 1.1 to 25.4, P = 0.043; OR: 7.6, 95% CI: 1.6 to 35.6, P = 0.010, respectively), but clinical outcome of 2 groups did not show any difference. For the risk factors for acquisition of binary toxin-positive isolates, previous use of glycopeptides was the significant risk factor (OR: 6.2, 95% CI: 1.4 to 28.6, P = 0.019), but use of probiotics worked as an inhibitory factor (OR: 0.1, 95% CI: 0.0 to 0.8; P = 0.026). PCR ribotypes of binary toxinproducing C. difficile showed variable patterns: ribotype 130, 4 isolates; 027, 3 isolates; 267 and 122, 1 each isolate and unidentified C1, 2 isolates. All 11 binary toxin-positive isolates were highly susceptible to clindamycin, moxifloxacin, metronidazole, vancomycin and piperacillin-tazobactam, however, 1 of 11 of the isolates was resistant to rifaximin. CONCLUSIONS: Binary toxin-producing C. difficile infection was not common in Korea and those isolates showed diverse PCR ribotypes with high susceptibility to antimicrobial agents. Glycopeptide use was a risk factor for CDI by those isolates.
Anti-Infective Agents ; Aza Compounds ; Clindamycin ; Clostridium ; Clostridium difficile ; Glycopeptides ; Humans ; Korea ; Leukocytosis ; Metronidazole ; Polymerase Chain Reaction ; Probiotics ; Prospective Studies ; Quinolines ; Ribotyping ; Risk Factors ; Sprains and Strains ; Treatment Outcome ; Vancomycin

The aim of this study was to evaluate the efficacy of levofloxacin and rifaximin based quadruple regimen as first-line treatment for Helicobacter pylori infection. A prospectively randomized, double-blinded, parallel group, comparative study was performed. Three hundred consecutive H. pylori positive patients were randomized to receive: omeprazole, amoxicillin, clarithromycin (OAC); omeprazole, amoxicillin, levofloxacin (OAL); and omeprazole, amoxicillin, levofloxacin, rifaximin (OAL-R). The eradication rates in the intention to treat (ITT) and per protocol (PP) analyses were: OAC, 77.8% and 85.6%; OAL, 65.3% and 73.6%; and OAL-R, 74.5% and 80.2%. The eradication rate achieved with OAC was higher than with OAL on the ITT (P = 0.05) and PP analysis (P = 0.04). OAL-R regimen was not inferior to OAC. The frequency of moderate to severe adverse effects was significantly higher in OAC treatment group. Especially, diarrhea was most common complaint, and there was a significantly low rate of moderate to severe diarrhea with the rifaximin containing regimen. In conclusion, the levofloxacin and rifaximin based regimen comes up to the standard triple therapy, but has a limited efficacy in a Korean cohort. The rifaximin containing regimen has a very high safety profile for H. pylori eradication therapy.
Adult ; Aged ; Amoxicillin/administration & dosage ; Anti-Bacterial Agents/*administration & dosage ; Clarithromycin/administration & dosage ; Diarrhea/chemically induced ; Double-Blind Method ; Drug Therapy, Combination ; Female ; Helicobacter Infections/complications/*drug therapy ; *Helicobacter pylori ; Humans ; Male ; Middle Aged ; Ofloxacin/*administration & dosage ; Omeprazole/administration & dosage ; Peptic Ulcer/complications/*drug therapy ; Prospective Studies ; Rifamycins/*administration & dosage

BACKGROUND: Group A Streptococcus (GAS) is responsible for a wide spectrum of human diseases. We investigated the distribution of emm types and antibiotic resistance rates of GAS from clinical specimens in several Korean medical centers. METHODS: A total of 192 strains of GAS from throat, blood, and other specimens collected in Seoul, Busan, Ulsan, Iksan, and Jeju were studied in 2008-2009. The emm genotypes were identified using PCR and sequencing. Antimicrobial susceptibility testing was performed by disk diffusion method. Phenotypes of macrolide resistance were evaluated, and macrolide resistance genes were determined by PCR. RESULTS: The emm89 (33.9%) was most frequently detected, followed by emm1 (12.5%), emm12 (8.3%), emm4 (7.8%), and emm75 (7.3%). The distribution of emm types did not show a close relation to the type of specimen and was different for each area. The resistance rates to erythromycin (ERY) and clindamycin (CLI) were 4.6% and 3.7%, respectively. Among the nine ERY-resistant strains, the rate of constitutive resistance was 88.9%, compared with 11.1% for the M phenotype. Five of the ERY-resistant strains were emm28. CONCLUSION: This multicenter study reveals heterogenous emm genotypes by geographic area. Rates of resistance to ERY and CLI were low, and most of the ERY-resistant strains showed a constitutive macrolide-lincosamide-streptogramin B (cMLSB) phenotype.
Clindamycin ; Diffusion ; Drug Resistance, Microbial ; Erythromycin ; Genotype ; Humans ; Korea ; Molecular Epidemiology ; Pharynx ; Phenotype ; Polymerase Chain Reaction ; Streptococcus ; Streptococcus pyogenes