BACKGROUND: Workers in the microbiology laboratories are continuously exposed to the risk of laboratory-associated infections. Tuberculosis (TB) is a frequent laboratory-acquired infection owing to production of cough-generated aerosols with ease and high infectivity of Mycobacterium tuberculosis. This study aims to investigate the current situation of biosafety in Korean TB laboratories. METHODS: We conducted a nationwide survey of laboratories in hospitals conducting TB tests using questionnaires about their facility and management standards. RESULTS: We analyzed data from 52 hospitals nationwide that have a capacity of 100–2,000 beds, of which only two laboratories conduct high risk drug-susceptibility testing on cultured isolates among other test items, whereas six laboratories perform only direct sputum-smear microscopy. The remaining laboratories performed moderate-risk activities/tests, like sample processing for culture. In the majority of these laboratories, there are laboratory medicine specialists who are fully in charge of health checkup programs for laboratorians. The facility and management standards vary widely according to the size of the hospital and risk of TB tests. CONCLUSIONS: Our survey results about the current situation of TB laboratories could be useful as baseline data for preparing biosafety guidelines for all TB laboratories in Korea.
Aerosols ; Korea* ; Microscopy ; Mycobacterium tuberculosis ; Specialization ; Tuberculosis*

Pregnancy represents an immunological paradox where the maternal immune system must tolerate the semi-allogeneic fetus expressing paternally-derived Ags. Accumulating evidence over decades has revealed that successful pregnancy requires the active development of robust immune tolerance mechanisms. This review outlines the multi-layered processes that establish fetomaternal tolerance, including the physical barrier of the placenta, restricted chemokine-mediated leukocyte trafficking, lack of sufficient alloantigen presentation, the presence of immunosuppressive regulatory T cells and tolerogenic decidual natural killer cells, expression of immune checkpoint molecules, specific glycosylation patterns conferring immune evasion, and unique metabolic/hormonal modulations. Interestingly, many of the strategies that enable fetal tolerance parallel those employed by cancer cells to promote angiogenesis, invasion, and immune escape. As such, further elucidating the mechanistic underpinnings of fetal-maternal tolerance may reciprocally provide insights into developing novel cancer immunotherapies as well as understanding the pathogenesis of gestational complications linked to dysregulated tolerance processes.

Pregnancy represents an immunological paradox where the maternal immune system must tolerate the semi-allogeneic fetus expressing paternally-derived Ags. Accumulating evidence over decades has revealed that successful pregnancy requires the active development of robust immune tolerance mechanisms. This review outlines the multi-layered processes that establish fetomaternal tolerance, including the physical barrier of the placenta, restricted chemokine-mediated leukocyte trafficking, lack of sufficient alloantigen presentation, the presence of immunosuppressive regulatory T cells and tolerogenic decidual natural killer cells, expression of immune checkpoint molecules, specific glycosylation patterns conferring immune evasion, and unique metabolic/hormonal modulations. Interestingly, many of the strategies that enable fetal tolerance parallel those employed by cancer cells to promote angiogenesis, invasion, and immune escape. As such, further elucidating the mechanistic underpinnings of fetal-maternal tolerance may reciprocally provide insights into developing novel cancer immunotherapies as well as understanding the pathogenesis of gestational complications linked to dysregulated tolerance processes.

Pregnancy represents an immunological paradox where the maternal immune system must tolerate the semi-allogeneic fetus expressing paternally-derived Ags. Accumulating evidence over decades has revealed that successful pregnancy requires the active development of robust immune tolerance mechanisms. This review outlines the multi-layered processes that establish fetomaternal tolerance, including the physical barrier of the placenta, restricted chemokine-mediated leukocyte trafficking, lack of sufficient alloantigen presentation, the presence of immunosuppressive regulatory T cells and tolerogenic decidual natural killer cells, expression of immune checkpoint molecules, specific glycosylation patterns conferring immune evasion, and unique metabolic/hormonal modulations. Interestingly, many of the strategies that enable fetal tolerance parallel those employed by cancer cells to promote angiogenesis, invasion, and immune escape. As such, further elucidating the mechanistic underpinnings of fetal-maternal tolerance may reciprocally provide insights into developing novel cancer immunotherapies as well as understanding the pathogenesis of gestational complications linked to dysregulated tolerance processes.

BACKGROUND: Cladosporium spp. are dematiaceous fungi that are commonly isolated from indoor and outdoor environments, including hospital air. This fungus is rarely pathogenic to humans, but has been reported to cause infections of the skin and toenails, as well as sinusitis and pulmonary infections. The monitoring of culture results was conducted to identify the outbreak of an unknown black fungal infection between January and March 2006 in a University hospital, and infection control activity was performed to identify the cause of the outbreak. METHODS: An epidemiological investigation of 22 patients with infections caused by an unknown black fungus was conducted. Microscopic examination and molecular analysis on the internal transcript spacer (ITS) region was performed to identify the black fungus. To detect the source of contamination, a culture of environmental specimens was performed, and then, disinfection of the laboratory was implemented. RESULTS: The patients with black fungi belonged to various departments and wards. No symptoms of fungal infection were recognized on the basis of the survey. The black fungus was identified as Cladosporium spp. on the basis of morphological features and ITS region sequencing. Culturing of environmental specimens was performed in the laboratory. Black fungi were isolated from a specimen from a rack and had the same morphological features with Cladosporium spp. from clinical specimens. After the rack was autoclaved, Cladosporium spp. from clinical specimens was no longer isolated. CONCLUSION: Epidemiological investigation, microscopic examination, and molecular analysis revealed that the sudden increase in the isolation rate of Cladosporium spp. from clinical specimens was the result of a pseudo-outbreak caused by the contamination of a rack. To our knowledge, this is the first report of a pseudo-outbreak of Cladosporium spp. Continuous monitoring of culture results is important to avoid unnecessary labor for nosocomial infection control.
Cladosporium ; Cross Infection ; Disinfection ; Fungi ; Humans ; Infection Control ; Nails ; Sinusitis ; Skin

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, with its accuracy and speed, is widely used for bacterial identification. The ASTA MicroIDSys system (ASTA, Korea) was recently developed for species identification. We compared its performance with that of Bruker Biotyper (Bruker Daltonics, Germany). Microbes were recovered from sputum, urine, and pus samples from patients admitted to a tertiary care hospital in Korea from January to April 2016. Matrix solution (α-cyano-4-hydroxycinnamic acid) was used, and the peptide profiles acquired from the Microflex LT (Bruker Daltonics) and Tinkerbell LT (ASTA) were analyzed by using their respective software. From 5,322 isolates, Bruker Biotyper identified 163 species; fifty species from 4,919 isolates were identified more than 10 times, including Klebsiella pneumoniae (n=571), Acinetobacter baumannii (n=436), Pseudomonas aeruginosa (n=358), Escherichia coli (n=372), Staphylococcus aureus (n=511), S. epidermidis (n=444), Enterococcus faecium (n=262), E. faecalis (n=220), and Candida albicans (n=248). Identical results, confidence scores (≥ 2.0 for Bruker Biotyper), and acceptable scores (≥140 for ASTA MicroIDSys) were obtained for 86.1% of isolates. Of 4,267 isolates, 99.2% showed acceptable scores in both systems. Results from the ASTA MicroIDSys showed good agreement with those from the Bruker Biotyper. The ASTA MicroIDSys could reliably identify clinically important microorganisms.
Acinetobacter baumannii ; Candida albicans ; Enterococcus faecium ; Escherichia coli ; Humans ; Klebsiella pneumoniae ; Korea ; Mass Spectrometry* ; Pseudomonas aeruginosa ; Sputum ; Staphylococcus aureus ; Suppuration ; Tertiary Healthcare

BACKGROUND: The recovery of bacteria from blood can be affected by many factors. Standardization of blood culture methods is important for reliability. Herein, we aimed to investigate blood culture protocols in Korea. METHODS: We performed a multicenter survey with a questionnaire about blood culture practices, which was sent by email to directors and clinical physicians in charge of clinical microbiology laboratories in May 2014. Total data from 18 participating hospitals were analyzed to be used as current baseline data, which is necessary to optimize blood culture protocols. RESULTS: Many laboratories included recommended blood volume, which is a major factor for bacteria recovery rate. This varied across participating laboratories. For adults, blood sampling of 10 mL was recommended by 10 laboratories and 20 mL was recommended by 5 laboratories. For children who weighed 14-36 kg and less than 14 kg, blood sampling of 10 mL (n=8) and 5 mL (n=7) was recommended, respectively. For neonates, less than 1 mL was recommended by 12 laboratories. CONCLUSION: Substantial variations in blood culture protocols were seen across participating clinical microbiology laboratories. Efforts to standardize this protocol should be undertaken.
Adult ; Bacteria ; Blood Volume ; Child ; Electronic Mail ; Humans ; Infant, Newborn ; Korea* ; Sepsis

BACKGROUND: Compliance with hand hygiene protocols is one of the simplest ways to prevent healthcare-associated infections (HAIs). Hand hygiene is influenced by individual habits and beliefs, as well as by local organizational culture practices. This study was performed in order to increase the rate of compliance to hand hygiene through changes in the organizational culture. METHODS: From 2009 through 2011, this study was performed in a 2,000-bed tertiary-care university hospital with more than 6,000 employees. The program was implemented mainly by team activities, and the leadership and hand hygiene steering committee members supported them. Goals for planning, intervention, and evaluation of the compliance rate for hand hygiene were made annually in the hospital. RESULTS: The rate of compliance to hand hygiene increased significantly each year (43.8% in 2008, 75.3% in 2009, 80.7% in 2010, and 83.2% in 2011). The detection rate of vancomycin-resistant Enterococcus (VRE) and the incidence of healthcare-associated Staphylococcus aureus bacteremia decreased. CONCLUSION: The rate of compliance to hand hygiene was remarkably improved, and it continuously increased through systematic and continuous changes in the organizational culture. In addition, the detection rate of VRE and incidence of S. aureus bacteremia decreased. These results show that hand hygiene is an important factor for preventing HAIs.
Bacteremia ; Committee Membership ; Compliance ; Enterococcus ; Hand Hygiene ; Incidence ; Organizational Culture ; Staphylococcus aureus

BACKGROUND: In general, higher resistance rates are observed among intensive care unit (ICU) isolates than non-ICU isolates. In this study, resistance rates of isolates from ICUs and non-ICUs were compared using the data generated from 20 hospitals in Korea. METHODS: Susceptibility data were collected from 20 hospitals participating in the Korean Nationwide Surveillance of Antimicrobial Resistance (KONSAR) program. Duplicate isolates were excluded from the analysis. The resistance rates did not include intermediate susceptibility. RESULTS: The most prevalent bacteria in the ICUs were Staphylococcus aureus (21%) and Acinetobacter spp. (19%), and those in non-ICU were Escherichia coli (27%) and S. aureus (14%). The resistance rates were higher in ICUs than in non-ICUs at 84% and 58% for methicillin-resistant S. aureus, 86% and 70% for methicillin-resistant coagulase-negative Staphylcoccus (CNS), 34% and 19% for vancomycin-resistant Enterococcus faecium, 38% and 19% for cefotaxime-resistant E. coli, 45% and 25% for cefotaxime-resistant Klebsiella pneumoniae, 42% and 24% for ceftazidime-resistant Enterobacter cloacae, 29% and 11% for ceftazidime-resistant Serattia marcescens, 83% and 44% for imipenem-resistant Acinetobacter spp., and 32% and 17% for imipenem-resistant Pseudomonas aeruginosa, respectively. CONCLUSION: The most prevalent bacteria in ICUs were S. aureus, CNS, and Acinetobacter spp., and high multi-drug resistance rates were observed in the Acinetobacter isolates. Therefore, infection control should be practiced in ICUs to prevent infections caused by multi-drug resistant bacteria.
Acinetobacter ; Bacteria ; Drug Resistance, Multiple ; Enterobacter cloacae ; Enterococcus faecium ; Escherichia coli ; Infection Control ; Intensive Care Units* ; Klebsiella pneumoniae ; Korea ; Methicillin Resistance ; Pseudomonas aeruginosa ; Staphylococcus aureus

Background: Numerous studies have examined the prevalence of Helicobacter pylori infection and clarithromycin (CLA) resistance rate of H. pylori. However, in South Korea, there is a lack of research analyzing specimens from local clinics and hospitals using molecular methods. This study aimed to assess the prevalence of H. pylori infection and CLA resistance across sex and age groups, as well as to explore regional variations in CLA resistance and its characteristics. Methods: Data from a laboratory information system from 2015 to 2018 were retrospectively analyzed to determine the prevalence of H. pylori infection and CLA resistance rate. The 23S ribosomal RNA genes of H. pylori were analyzed using a dual priming oligonucleotide-based multiplex polymerase chain reaction method. Results: The overall prevalence of H. pylori infection was 50.5%(12,000/23,773), with a significantly higher prevalence among males (53.5%) than females (47.0%). The CLA resistance rate was 28.3%, with a significantly higher rate among females (34.9%) than males (23.8%). Age group analysis revealed that the highest prevalence of H. pylori infection was among individuals in their 40s, whereas the highest CLA resistance rate was observed among those in their 60s. The CLA resistance rate exhibited an upward trend and varied among patients based on their place of residence, and A2143G mutation was the most prevalent across all regions. Conclusion The prevalence of H. pylori infection and CLA resistance rate in Korea remain high and vary according to sex, age, and region. To effectively eradicate H. pylori, it is crucial to periodically monitor regional CLA resistance patterns and conduct CLA susceptibility testing before prescription.