BACKGROUND: Acute viral gastroenteritis is a common illness in young children. Rotavirus, norovirus and enteric adenovirus are the major agents for viral gastroenteritis. Their detection rates have gradually increased in Korea. Our aim was to monitor the epidemiologic characteristics of the aforementioned viruses and to determine the laboratory and clinical characteristics of pediatric patients infected with these viruses. METHODS: From December 2009 to November 2010, 685 stool specimens from patients hospitalized at Chung-Ang University Hospital were tested for the aforementioned viruses using multiplex PCR. A corresponding medical record review was retrospectively conducted. RESULTS: The overall prevalence rate was 44.8%, with rates of 16.3%, 1.9%, 22.7%, 3.1%, and 0.8% for rotavirus, norovirus genogroup I, norovirus genogroup II, enteric adenovirus, and astrovirus, respectively. Mixed virus infections were detected in 37 patients (5.4%). The highest incidence rates occurred in March 2010 (18.9%), in the 13-24 month age group (38.1%), and in males (53.1%). Fever and chills were most frequently observed in patients with adenovirus (44.4%) than other viruses, while diarrhea was most frequently observed in patients with rotavirus (93.7%). Leukocytosis (55.0%) and lymphocytosis (21.0%) were more common in the norovirus-infected group than other viruses-infected group. CONCLUSION: Our results show different prevalence rates and clinical findings for each gastroenteritis-associated virus. To better understand the clinico-epidemiological features observed in this study, further epidemiologic and clinical investigations are needed.
Adenoviridae ; Child ; Chills ; Diarrhea ; Epidemiology ; Fever ; Gastroenteritis* ; Genotype ; Humans ; Incidence ; Korea ; Leukocytosis ; Lymphocytosis ; Male ; Medical Records ; Multiplex Polymerase Chain Reaction ; Norovirus ; Pediatrics ; Polymerase Chain Reaction ; Prevalence ; Retrospective Studies ; Rotavirus ; Tertiary Healthcare*

BACKGROUND: Group B streptococcus (Streptococcus agalactiae, GBS) was reported as a major cause of neonatal infection and death. To prevent vertical transmission, CDC recommended that all women in week 35-37 of pregnancy should receive the GBS colonization test. We conducted a systematic review and meta-analysis to evaluate diagnostic accuracy and detection rate of real-time PCR for GBS in pregnant women. METHODS: The literature review for GBS using real-time PCR was done including KoreaMed, Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library on November 3, 2015. 443 articles were collected. Two authors select articles and evaluated the quality of studies using Scottish Intercollegiate Guidelines Network tool independently. RESULTS: Diagnostic accuracy of the real-time PCR was assessed by meta-analysis through 34 articles (13,516 for real-time PCR, 1,815 for culture and other comparison test). The GBS colonization was assessed through 34 articles, which reported varying values of 2.0–69.2% using real-time PCR. The real-time PCR for GBS was shown to have overall sensitivity of 0.93 (95% CI 0.92–0.94, I2=86.3%), overall specificity of 0.96 (95% CI 0.96–0.96, I2=90.2%), SROC AUC of 0.99. CONCLUSION: Real-time PCR is an effective test for detecting GBS colonization in pregnant women, resulted in preventing the infection in a new born baby.
Area Under Curve ; Centers for Disease Control and Prevention (U.S.) ; Colon* ; Female ; Humans ; Pregnancy ; Pregnant Women* ; Real-Time Polymerase Chain Reaction* ; Sensitivity and Specificity ; Streptococcus ; Streptococcus agalactiae

BACKGROUND: Cumulative blood culture data provide clinicians with important information in the selection of empiric therapy for blood stream infections. METHODS: We retrospectively analyzed blood culture data from a university hospital during the period from 2006 to 2015. Only the initial isolates of a given species for each patient were included. RESULTS: The number of blood cultures per 1,000 inpatient-days increased from 64 in 2006 to 117 in 2015. The ratio of significant pathogens to total isolates was 0.56-0.63. The most common organisms were Escherichia coli in 2006-2010 but changed to coagulase-negative staphylococci (CoNS) in 2011. The proportion of Staphylococci aureus was decreased during the study period, but Klebsiella pneumoniae was increased. Enterococci were increased, especially E. faecium, which was more frequently isolated than E. faecalis in 2015. Pseudomonas aeruginosa was decreased during the study, but Acinetobacter baumannii was increased. The prevalence of methicillin-resistant S. aureus (MRSA) changed from 62.2% to 53.9%, while vancomycin-resistant E. faecium increased to 35.8%. Extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae increased to 25% and 34%, respectively, in 2015. Starting in 2008, three E. coli and 11 K. pneumoniae isolates were carbapenem-resistant Enterobacteriaceae (CRE), and three were carbapenemase-producing Enterobacteriaceae (CPE). The prevalence of imipenem-resistant A. baumannii rapidly increased during the study period. CONCLUSION: About 60% of all blood isolates were significant pathogens. The most common isolates changed from E. coli to CoNS in 2011. ESBL-producing E. coli and K. pneumoniae, vancomycin-resistant E. faecium, and imipenem-resistant A. baumannii were increased during the study, while the proportion of MRSA tended to decrease slightly. Of the total isolates, 14 were CRE, and 3 were CPE.
Acinetobacter baumannii ; Bacteremia ; beta-Lactamases ; Enterobacteriaceae ; Escherichia coli ; Humans ; Klebsiella pneumoniae ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Pneumonia ; Prevalence ; Pseudomonas aeruginosa ; Retrospective Studies ; Rivers

As many emerging human infections are caused by viruses, laboratory-acquired viral infection will become more common. However, additional knowledges is needed, including actual incidence, disinfectant, and prevention. Although the general biosafety principles of viruses do not differ from those of other microorganisms, biosafety guidelines and programs are not immutable and could vary according to virus and laboratory environment. Most laboratory-acquired viral infections reported in the literature were caused by violation of biosafety principles.
Humans ; Incidence ; Laboratory Infection ; Occupational Diseases ; Virus Diseases

Human cytomegalovirus (CMV) is a clinically important pathogen that causes significant morbidity and mortality in immunocompromised patients and is typically monitored using real-time polymerase chain reaction (real-time PCR). International standards and certified reference materials were recently developed by the WHO, providing the opportunity to standardize viral load reporting. Clinical microbiologists who conduct quantitative CMV DNA testing should be aware of technical issues that can affect the analytical and clinical performance of the method used. These include specimen type, limits of detection and quantification, linear range, reproducibility, and wide variability in viral load values among different assays. Specimen types for testing include whole blood, plasma, serum, and peripheral blood leukocytes. The tests that use whole blood and peripheral blood leukocytes have higher sensitivities. Adsorption chromatography methods are widely used for nucleic acid extraction, and efficiencies can differ between manual and automatic processes. The most common method for quantitative CMV DNA testing is real-time PCR. All CMV testing methods require quality control at the pre-analytic, analytic, and post-analytic stages. In transplant patients, specific quantitative results and monitoring of any changes at follow-up are important. Five to seven days is an adequate follow-up interval in this regard, and drug-resistant CMV should be suspected if there is no response to therapy. One specimen type should be chosen for follow-up quantitative CMV DNA testing, optimized according to WHO standards. Further studies are needed to better standardize CMV testing approaches and to determine the appropriate clinical cut-off level.
Adsorption ; Chromatography ; Cytomegalovirus* ; DNA* ; Follow-Up Studies ; Humans ; Immunocompromised Host ; Leukocytes ; Limit of Detection ; Methods ; Mortality ; Plasma ; Polymerase Chain Reaction* ; Quality Control ; Real-Time Polymerase Chain Reaction ; Viral Load

Mycobacterium abscessus was isolated from cultures of seven blood samples from a 64-year-old diabetic female who was admitted due to steroid-unresponsive adrenal insufficiency. The isolates were difficult to identify using the conventional commercial systems, VITEK 2 (bioMérieux, France) or MicroScan (Siemens Healthcare Diagnostics, USA), but were rapidly identified as M. abscessus by a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based Bruker Biotyper system (Bruker Daltonics, USA). Identification of M. abscessus was confirmed by a reverse hybridizationbased assay (Genotype Mycobacterium CM/AS 12, Hain Lifescience) and direct sequencing of a heatshock protein gene. After removal of her central venous catheter, the patient was successfully treated with a combination therapy comprising clarithromycin, amikacin, cefoxitin, and imipenem. Our findings demonstrate that MALDI-TOF MS can facilitate rapid and accurate identification of M. abscessus from blood cultures, which enables prompt administration of appropriate therapy following catheter removal.
Adrenal Insufficiency ; Amikacin ; Bacteremia* ; Catheters ; Cefoxitin ; Central Venous Catheters ; Clarithromycin ; Delivery of Health Care ; Diagnosis* ; Female ; Humans ; Imipenem ; Mass Spectrometry* ; Middle Aged ; Mycobacterium*

BACKGROUND: Blood cultures are essential in diagnosing and treating sepsis. There are several factors that affect the diagnostic yield of blood cultures such as the number of blood sampling episodes, the incubation period, the type and volume of culture media, and the amount of blood drawn. This study aimed to elucidate whether monitoring the volume of blood drawn with an educational intervention could affect the diagnostic quality of blood cultures. METHODS: We implemented quality monitoring for the blood volume drawn during blood culture testing for adults in an emergency room. We instructed the nurses in the emergency room to draw the optimal amount of blood and to reduce the number of blood culture sets from three to two. We analyzed and compared the amount of blood drawn, the rate of positive blood cultures, the contamination rate, and time to positivity (TTP) between 908 patients pre-intervention and 921 patients post-intervention. RESULTS: The amount of blood drawn increased from 0.7±0.3 mL per bottle (pre-intervention) to 6.5±1.7 mL per bottle (post-intervention) (P<0.0001). The rate of positive blood culture post-intervention (12.14%) was higher than that pre-intervention (6.65%) (P<0.0001). The contamination rate post-intervention (1.82%) was also significantly greater than that pre-intervention (0.60%) (P<0.0001). Except for anaerobes, there was no significant difference in the distribution of microorganisms between the pre- and post-intervention periods. The TTP for anaerobe bottles post-intervention was significantly shorter than that of pre-intervention (16.1±16.3 versus 18.6±18.3 h). CONCLUSION: This study suggests that continuing education about adequate blood volume and aseptic techniques is needed to increase the rate of positive blood cultures and reduce the contamination rate of blood cultures.
Adult ; Blood Volume* ; Culture Media ; Education, Continuing ; Emergencies* ; Emergency Service, Hospital* ; Humans ; Sepsis

BACKGROUND: Sequence type 131 (ST131) O25b serogroup Escherichia coli, producing CTX-M type extended-spectrum β-lactamase (ESBL), is a major clone involved in worldwide pandemic spread in both community- and healthcare-associated infections. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become a routine tool for the identification of bacteria in many laboratories. This study aimed to assess the performance of MALDI-TOF MS for the screening of ESBL-producing E. coli ST131 in a rapid, inexpensive, and simple way. METHODS: A total 26 clinical E. coli, isolated from blood between 2013 and 2014, were used. The characteristics are ST131-O25b ESBL producers (n=6), ST131-O16 ESBL producers (n=4), non-ST131 ESBL producers (n=11), and non-ST131 non-ESBL producers (n=5). Specific biomarker peaks to distinguish the ST131 clonal group from others were investigated by MicroIDSys (ASTA, South Korea) and ASTA Tinkerbell 2.0 software. RESULTS: A peak at 9,713 m/z peak is useful to screen for ST131 E. coli, regardless of serogroup O25 or O16, showing a sensitivity of 100%, specificity of 56.2%, positive predictive value of 58.8%, and negative predictive value of 100% when using a relative intensity cutoff of 15%. CONCLUSION: We can screen for ST131 E. coli using MicroIDSys (ASTA), MALDI-TOF MS in a rapid, inexpensive, and simple way. However, other confirmatory tests are needed to confirm ST131 E. coli due to the low specificity of this method.
Bacteria ; Clone Cells ; Escherichia coli* ; Escherichia* ; Mass Screening ; Mass Spectrometry* ; Methods ; Pandemics ; Sensitivity and Specificity ; Serogroup

BACKGROUND: Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are resistant to most β-lactam antibiotics except carbapenems. In recent years, infrequently isolated Enterobacteriaceae that produce carbapenemase pose a serious threat in the selection of appropriate therapeutic antibiotics. The rapid detection method of carbapenemase-producing Enterobacteriaceae (CPE) is necessary to prevent the spread of CPE into healthcare facilities. METHODS: One hundred clinical Enterobacteriaceae isolates (Klebsiella pneumoniae 40, Escherichia coli 40, others 20) showing susceptibility to carbapenems and positivity in the CLSI ESBL phenotypic test from November 2015 to March 2016 and 59 stocked Enterobacteriaceae isolates harboring resistance genes producing carbapenemase (K. pneumoniae 56, Enterobacter cloacae 2, E. coli 1; types of CPE: KPC 36, GES 12, NDM 6, VIM 2, OXA 2, IMP 1) were subjected to the RAPIDEC CARBA NP test (bioMérieux, France) and CPE phenotypic test using the modified Hodge test (MHT) and carbapenemase inhibition test. RESULTS: All of the 100 Enterobacteriaceae isolates with carbapenem susceptibility and ESBL positivity were negative on the RAPIDEC CARBA NP test and CPE phenotypic test. Of 59 stock CPE isolates, 53 and 42 showed positive results to the RAPIDEC CARBA NP test and MHT, respectively. The sensitivity and specificity of the RAPIDEC CARBA NP test for detecting CPE were 89.8% and 100%, respectively. CONCLUSION: The RAPIDEC CARBA NP test is simple and produces a result within 3 hr. In conclusion, the test is a useful screen for detecting CPE because it shows high sensitivity and specificity for CPE detection.
Anti-Bacterial Agents ; Carbapenems ; Delivery of Health Care ; Enterobacter cloacae ; Enterobacteriaceae* ; Escherichia coli ; Methods ; Pneumonia ; Sensitivity and Specificity

Erysipelothrix rhusiopathiae is a Gram-positive bacillus that causes infections primarily in animals. In humans, the bacteria usually cause localized or generalized cutaneous infections. A 75-year-old man with chronic alcoholism presented with abdominal pain. Abdominal computed tomography and laboratory findings suggested an intra-abdominal abscess in the periaortic soft tissue. While no definitive infectious source was identified, E. rhusiopathiae was identified by 16S rRNA-based gene sequencing from culture-negative, periaortic necrotic tissue, subsequent to empiric antibiotic treatment. It is suggested that E. rhusiopathiae has the potential to cause intra-abdominal abscesses. This case report highlights the usefulness of DNA sequencing to identify pathogens in patients pretreated with antibiotics.
Abdominal Abscess* ; Abdominal Pain ; Abscess ; Aged ; Alcoholism ; Animals ; Anti-Bacterial Agents ; Bacillus ; Bacteria ; Erysipelothrix* ; Humans ; Sequence Analysis, DNA*