Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 238
Filter
1.
Article in English | WPRIM | ID: wpr-913381

ABSTRACT

Background@#Environmental sanitation plays a significant role on the prevalence of enteropathogenic bacteria. This study aimed to determine the trends in the prevalence and antimicrobial resistance profiles of enteropathogenic bacteria from 2011 to 2019. @*Methods@#A retrospective analysis was performed using data from stool cultures of Salmonella spp., Shigella spp., Plesiomonas shigelloides , Yersinia spp., Vibrio spp., and Campylobacter spp. Samples were obtained between 2011 and 2019 from Severance Hospital. Antimicrobial susceptibility profile was determined using the disk diffusion method for nontyphoidal Salmonella (NTS) and Campylobacterspp., following the Clinical and Laboratory Standards Institute (CLSI) guidelines. @*Results@#The number of specimens obtained for stool culture increased significantly from 13,412 during the period of 1969–1978, to 48,476 over the past nine years (2011–2019), whereas the ratio of positive specimens decreased significantly from 1,732 (12.9%) to 449 (0.9%). The proportion of samples positive for Salmonella Typhi decreased from 472 (93.6%, 1969–1978) to 4 (1.5%, 2011–2019), whereas the proportion of NTS increased from 14 (2.8%, 1969–1978) to 261 (96.7%, 2011–2019). Among all the enteropathogenic bacteria isolated, Shigella spp. accounted for 60.0% (1,039) isolates from 1969 to 1978, but only 1.6% (7) from 2011 to 2019. Campylobacter was the second most prevalent enteropathogenic bacteria, accounting for 29.4% isolates (132). Among the NTS strains isolated from 2016 to 2019, their susceptibility rates to ampicillin and sulfamethoxazole-trimethoprim were 51.1% and 85.2%, respectively. Additionally, the susceptibility rate of Campylobacter to ciprofloxacin was 15.8%. @*Conclusion@#The prevalence of Salmonella Typhi and Shigella spp. significantly decreased, whereas those of NTS and Campylobacter spp. increased. Therefore, continuous monitoring of ciprofloxacin-resistant Campylobacter spp. is of vital importance.

2.
Article in English | WPRIM | ID: wpr-874188

ABSTRACT

Background@#One health is a flexible concept with many facets, including the environment, community, and the nosocomial super-bacteria resistance network. We investigated the molecular prevalence of extended-spectrum-β-lactamase-producing Escherichia coli (ESBL-EC) in workers, livestock, and the farm environment in Korea. @*Methods@#ESBL-EC isolates were obtained from samples from 19 swine farms, 35 retail stores, seven slaughterhouses, and 45 related workers throughout Korea from August 2017 to July 2018, using ChromID ESBL (BioMérieux, Marcy l’Etoile, France) agar and enrichment broth. The presence of ESBL and mobilized colistin resistance (mcr) genes and antimicrobial resistance were determined. Clonality was evaluated with pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). @*Results@#In total, 232 ESBL-EC isolates were obtained from 1,614 non-duplicated samples (14.4% positive rate). The ESBL-EC isolates showed regional and source-related differences. blaCTX-M-55 (N = 100), blaCTX-M-14 (N = 65), blaCTX-M-15 (N = 33), and blaCTX-M-65 (N = 23) were common ESBL types. The ESBL-EC isolates showed high resistance rates for various antimicrobial classes; however, all isolates were susceptible to carbapenem. One swine-originating colistin-resistant isolate did not carry any known mcr gene. PFGE was successful for 197 of the 232 isolates, and most PFGE types were heterogeneous, except for some dominant PFGE types (O, R, T, U, and V). MLST of 88 isolates was performed for representative PFGE types; however, no dominant sequence type was observed. @*Conclusions@#The proportion of ESBL-EC in swine industry-related samples was significant, and the isolates harbored common clinical ESBL gene types. These molecular epidemiologic data could provide important evidence for antimicrobial-resistance control through a one health approach.

3.
Article in English | WPRIM | ID: wpr-874076

ABSTRACT

Background@#The purpose of this study was to analyze the clinical and microbiological characteristics of recurrent urinary tract infection (UTI) caused by Escherichia coli— the most common etiological agent. @*Methods@#Cases of recurrent and single episodes of UTI caused by E. coli were evaluated retrospectively for a period of 6 months (January-June 2019) to analyze the clinical and molecular characteristics of this disease. @*Results@#Healthcare-associated UTI, E. coli bacteremia, and poor microbial clearance 7 days post infection were associated more with the recurrent episodes of infection. E. coli isolates from subjects with recurrent UTIs showed higher rates of antimicrobial resistance and extended-spectrum β-lactamase (ESBL) production. The E. coli clone— sequence type 131 was detected in similar proportions in isolates, recovered from subjects in both groups— recurrent episodes and single episode of UTI. @*Conclusion@#The control of antimicrobial-resistant ESBL-producing E. coli strains may be difficult using antimicrobial therapy and subsequently delay the clearance of the etiologic agent. This could play a major role in the development of recurrent UTIs.

4.
Article in English | WPRIM | ID: wpr-762470

ABSTRACT

Active surveillance culture (ASC) can help detect hidden reservoirs, but the routine use of ASC for extended spectrum β-lactamase-producing Enterobacteriaceae is controversial in an endemic situation. We aimed to determine the prevalence and risk factors of extended spectrum β-lactamase-producing Klebsiella pneumoniae (EBSL-Kpn) colonization among intensive care unit (ICU)-admitted patients. Prospective screening of ESBL-Kpn colonization was performed for ICU-admitted patients within 48 hours for two months. A perirectal swab sample was inoculated on MacConkey agar supplemented with 2 µg/mL ceftazidime. ESBL genotype was determined by PCR-sequencing, and clonal relatedness was evaluated by pulsed-field gel electrophoresis (PFGE). The risk factors of ESBL-Kpn colonization were evaluated. The ESBL-Kpn colonization rate among the 281 patients at ICU admission was 6.4% (18/281), and bla(CTX-M-15) was detected in all isolates. ESBL producers also showed resistance to fluoroquinolone (38.9%, 7/18). All isolates had the same ESBL genotype (bla(CTX-M-15)) and a highly clustered PFGE pattern, suggesting cross-transmission without a documented outbreak. In univariate analysis, the risk factor for ESBL-Kpn colonization over the control was the length of hospital stay (odds ratio=1.062; P=0.019). Routine use of ASC could help control endemic ESBL–Kpn for ICU patients.


Subject(s)
Agar , Ceftazidime , Colon , Critical Care , Electrophoresis, Gel, Pulsed-Field , Enterobacteriaceae , Genotype , Humans , Intensive Care Units , Klebsiella pneumoniae , Klebsiella , Length of Stay , Mass Screening , Prevalence , Prospective Studies , Risk Factors
7.
Article in English | WPRIM | ID: wpr-816604

ABSTRACT

BACKGROUND: The weather has well-documented effects on infectious disease and reports suggest that summer peaks in the incidences of gram-negative bacterial infections among hospitalized patients. We evaluated how season and temperature changes affect bloodstream infection (BSI) incidences of major pathogens to understand BSI trends with an emphasis on acquisition sites.METHODS: Incidence rates of BSIs by Staphylococcus aureus, Enterococcus spp., Escherichia coli, Klebsiella pneumoniae, Acinetobacter spp., and Pseudomonas aeruginosa were retrospectively analyzed from blood cultures during 2008–2016 at a university hospital in Seoul, Korea according to the acquisition sites. Warm months (June–September) had an average temperature of ≥20℃ and cold months (December–February) had an average temperature of ≤5℃.RESULTS: We analyzed 18,047 cases, where 43% were with community-onset BSI. E. coli (N = 5,365) was the most common pathogen, followed by Enterococcus spp. (N = 3,980), S. aureus (N = 3,075), K. pneumoniae (N = 3,043), Acinetobacter spp. (N = 1,657), and P. aeruginosa (N = 927). The incidence of hospital-acquired BSI by Enterococcus spp. was weakly correlated with temperature, and the median incidence was higher during cold months. The incidence of community-onset BSI by E. coli was higher in warm months and was weakly correlated with temperature.CONCLUSION: We found seasonal or temperature-associated variation in some species-associated BSIs. This could be a useful information for enhancing infection control and public health policies by taking season or climate into consideration.


Subject(s)
Acinetobacter , Climate , Climate Change , Communicable Diseases , Enterococcus , Escherichia coli , Gram-Negative Bacterial Infections , Humans , Incidence , Infection Control , Klebsiella pneumoniae , Korea , Pneumonia , Pseudomonas aeruginosa , Public Health , Retrospective Studies , Seasons , Seoul , Staphylococcus aureus , Tertiary Care Centers , Weather
9.
Infection and Chemotherapy ; : 365-375, 2019.
Article in English | WPRIM | ID: wpr-914565

ABSTRACT

BACKGROUND@#The intestinal microbiota plays an important role in the pathogenesis of Clostridioides difficile-associated diarrhea, and regional and racial characteristics influence the microbiome composition and diversity. We investigated the intestinal microbiome characteristics of patients with C. difficile colitis (CD+) compared to those of patients with colitis not due to C. difficile (CD−), patients with vancomycin-resistant enterococci (VRE) colonization, and healthy controls, in Korea.@*MATERIALS AND METHODS@#We collected stool samples from 24, 18, 11 and 13 subjects within CD+, CD−, VRE and healthy control groups, respectively. The microbial communities were evaluated by 454-pyrosequencing of bacterial 16s rRNA.@*RESULTS@#The species richness and microbial diversity were significantly lower in the CD+ group compared to those in healthy controls, but not compared to those in CD− and VRE groups. Phylum-level analysis showed that the proportion of Actinobacteria in the CD+ group was significantly lower than in the healthy control, but was unchanged compared to that in CD− and VRE groups. At the genus level, compared to the healthy group, the CD+ group showed significantly lower proportions of Blautia, Bifidobacterium, Faecalibacterium et al. Compared to the VRE group, the CD+ group showed a significantly higher proportion of Anaerostipes.@*CONCLUSIONS@#We could identify the intestinal microbiome characteristics of Koreans with C. difficile colitis. It might help to develop microbiome based diagnostic and treatment modalities.

11.
12.
Article in English | WPRIM | ID: wpr-715662

ABSTRACT

BACKGROUND: We investigated the molecular epidemiological characteristics and antimicrobial susceptibility pattern of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates to monitor the change in distribution of bla(TEM) in Korea. METHODS: We collected 804 PPNG isolates from diverse hospitals and clinics mainly located in Seoul, Korea, over a period of 11 years (2005–2015). Isolate susceptibility to seven antimicrobials was determined using the agar dilution test. The molecular epidemiological characteristics of the isolates were determined by Sanger sequencing of bla(TEM), N. gonorrhoeae multiantigen sequence typing (NG-MAST) and plasmid typing. RESULTS: Among 72 fully sequenced PPNG isolates, sixteen (22.2%) possessed TEM-135. All TEM-135 isolates had a common silent mutation (c.18C>T), which was previously unreported. We observed a pattern of continuous increase in the number of TEM-135 isolates since 2012. The median and 90% minimum inhibitory concentration of azithromycin were substantially lower in the TEM-135 group than in the non-PPNG and TEM-1 groups. All TEM-135 isolates showed different NG-MAST types and predominantly harbored Toronto/Rio (75%) plasmids. A comprehensive comparative analysis of PPNG with TEM-135 according to NG-MAST, plasmid type, and year of isolation revealed a wide distribution. CONCLUSIONS: The proportion of TEM-135 PPNG has continuously increased since 2012, in association with clonal spread. The difference at position 18 of the TEM-135 sequence can be interpreted as the existence of multiple clonal complexes. The possibility that TEM-135 was acquired via foreign plasmids requires careful follow-up and continuous monitoring of TEM-135 to ascertain whether it constitutes a step towards evolutionary change.


Subject(s)
Agar , Azithromycin , Drug Resistance, Microbial , Follow-Up Studies , Incidence , Korea , Microbial Sensitivity Tests , Neisseria gonorrhoeae , Neisseria , Plasmids , Seoul , Silent Mutation
13.
Infection and Chemotherapy ; : 149-152, 2018.
Article in English | WPRIM | ID: wpr-721994

ABSTRACT

Brucellosis is a zoonotic infection that is usually transmitted from cattle to humans through ingestion of animal milk, direct contact with animal parts, or inhalation of aerosolized particles. In Korea, brucellosis seem to be transmitted through close contact with blood, fetus, urine, and placenta of domestic cow that has been infected by Brucella abortus, or inhalation of B. arbortus while examining or slaughtering cow. Brucella melitensis infection is rare in Korea and there have been no reported cases of B. melitensis originating from other countries until now. This report details a case of complicated brucellosis with infective spondylitis in a 48-year-old male construction worker recently returned from Iraq. Infection with B. melitensis was confirmed using 16s rRNA sequencing and omp31 gene analysis. The patient was successfully treated using a combination of rifampin, doxycycline, and streptomycin, in accordance with WHO guidelines. This is the first reported case of complicated brucellosis with infective spondylitis in Korea caused by B. melitensis originating from Iraq.


Subject(s)
Animals , Brucella abortus , Brucella melitensis , Brucella , Brucellosis , Cattle , Doxycycline , Eating , Fetus , Humans , Inhalation , Iraq , Korea , Male , Middle Aged , Middle East , Milk , Placenta , Rifampin , Spondylitis , Streptomycin , Zoonoses
14.
Infection and Chemotherapy ; : 149-152, 2018.
Article in English | WPRIM | ID: wpr-721489

ABSTRACT

Brucellosis is a zoonotic infection that is usually transmitted from cattle to humans through ingestion of animal milk, direct contact with animal parts, or inhalation of aerosolized particles. In Korea, brucellosis seem to be transmitted through close contact with blood, fetus, urine, and placenta of domestic cow that has been infected by Brucella abortus, or inhalation of B. arbortus while examining or slaughtering cow. Brucella melitensis infection is rare in Korea and there have been no reported cases of B. melitensis originating from other countries until now. This report details a case of complicated brucellosis with infective spondylitis in a 48-year-old male construction worker recently returned from Iraq. Infection with B. melitensis was confirmed using 16s rRNA sequencing and omp31 gene analysis. The patient was successfully treated using a combination of rifampin, doxycycline, and streptomycin, in accordance with WHO guidelines. This is the first reported case of complicated brucellosis with infective spondylitis in Korea caused by B. melitensis originating from Iraq.


Subject(s)
Animals , Brucella abortus , Brucella melitensis , Brucella , Brucellosis , Cattle , Doxycycline , Eating , Fetus , Humans , Inhalation , Iraq , Korea , Male , Middle Aged , Middle East , Milk , Placenta , Rifampin , Spondylitis , Streptomycin , Zoonoses
15.
Article in English | WPRIM | ID: wpr-714433

ABSTRACT

BACKGROUND: Early and appropriate antibiotic treatment improves the clinical outcome of patients with septicemia; therefore, reducing the turn-around time for identification (ID) and antimicrobial susceptibility test (AST) results is essential. We established a method for rapid ID and AST using short-term incubation of positive blood culture broth samples on solid media, and evaluated its performance relative to that of the conventional method using two rapid ID systems and a rapid AST method. METHODS: A total of 254 mono-microbial samples were included. Positive blood culture samples were incubated on blood agar plates for six hours and identified by the MicroFlex LT (Bruker Daltonics) and Vitek-MS (bioMeriéux) systems, followed by AST using the Vitek2 System (bioMeriéux). RESULTS: The correct species-level ID rates were 82.3% (209/254) and 78.3% (199/254) for the MicroFlex LT and Vitek-MS platforms, respectively. For the 1,174 microorganism/antimicrobial agent combinations tested, the rapid AST method showed total concordance of 97.8% (1,148/1,174) with the conventional method, with a very major error rate of 0.5%, major error rate of 0.7%, and minor error rate of 1.0%. CONCLUSIONS: Routine implementation of this short-term incubation method could provide ID results on the day of blood culture-positivity detection and one day earlier than the conventional AST method. This simple method will be very useful for rapid ID and AST of bacteria from positive blood culture bottles in routine clinical practice.


Subject(s)
Agar , Bacteria , Humans , Methods , Sepsis
16.
Article in English | WPRIM | ID: wpr-714428

ABSTRACT

Identifying the trends in community-onset Acinetobacter baumannii complex isolation and diversity according to temperature could help provide insight into the behavior of the A. baumannii complex. We performed a retrospective analysis of A. baumannii complex (Acinetobacter baumannii, Acinetobacter nosocomialis, Acinetobacter pittii, and Acinetobacter calcoaceticus) isolates obtained from patients at a Korean community hospital from 2006 to 2015 with reference to seasonal temperatures. The incidence rates were compared between warm (June–September) and cold (November–March) months, defined as an average mean temperature ≥20℃ and ≤5℃, respectively. Incidence rate was calculated as the number of cases per month, converted to cases/10⁵ admissions for healthcare-acquired isolates and cases/10³ outpatients for community-onset isolates. Approximately 3,500 A. baumannii complex cases were identified, and 26.2% of them were community-onset cases. The median (interquartile range) number of community-onset A. baumannii complex cases was significantly higher (P=0.0002) in warm months at 13.8 (9.5–17.6) than in cold months at 10.1 (6.3–13.2). There was a strong correlation between community-onset A. baumannii complex cases and temperature (Pearson's r=0.6805, P=0.0149). Thus, we identified a seasonality pattern for community-onset A. baumannii complex colonization or infection, but not for healthcare-acquired cases.


Subject(s)
Acinetobacter baumannii , Acinetobacter , Colon , Hospitals, Community , Humans , Incidence , Outpatients , Retrospective Studies , Seasons
18.
Article in English | WPRIM | ID: wpr-713438

ABSTRACT

BACKGROUND: Listeriosis caused by Listeria monocytogenes has a high case-fatality rate (CFR) of approximately 20% to 30%. An increasing incidence of listeriosis has been reported in many countries recently. We investigated the annual incidence, clinical characteristics, and outcomes of listeriosis at three different hospitals in Korea and evaluated the effects of appropriate empiric antimicrobial treatments on patient outcomes. METHODS: We retrospectively collected the data of all culture-positive cases of human listeriosis from three hospitals of different sizes in Korea during 2006–2016 and calculated the annual number of cases and incidence per 100,000 admissions. RESULTS: A total of 58 patients with L. monocytogenes were included in this study. The incidence of listeriosis was significantly higher in 2013–2016 than in 2006–2012 (RR 3.1; 95% CI 1.79–5.36; P < 0.001), mainly because of an increase in patients over 60 years of age (RR 3.69; 95% CI 1.70–8.02; P < 0.001). Multivariate analysis showed that healthcare-associated infection (adjusted OR, 12.15; 95% CI, 2.56–86.01; P=0.004) and empirical treatment with first-line antimicrobial agents (adjusted OR, 0.08; 95% CI, 0.00–0.63; P=0.044) were associated with CFR. CONCLUSIONS: Healthcare-associated infections caused by L. monocytogenes are associated with high CFR. Adequate initial empirical treatments could reduce CFR, suggesting that careful consideration of an empirical antimicrobial regimen is warranted for elderly or immunocompromised patients admitted to the hospital.


Subject(s)
Aged , Anti-Infective Agents , Humans , Immunocompromised Host , Incidence , Korea , Listeria monocytogenes , Listeriosis , Multivariate Analysis , Retrospective Studies
19.
Article in English | WPRIM | ID: wpr-713437

ABSTRACT

BACKGROUND: Diverse microbiota exist in the lower respiratory tract. Although next generation sequencing (NGS) is the most widely used microbiome analysis technique, it is difficult to implement NGS in clinical microbiology laboratories. Therefore, we evaluated the performance of conventional culture methods together with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in identifying microbiota in bronchoalveolar lavage (BAL) fluid. METHODS: BAL fluid samples (n=27) were obtained from patients undergoing diagnostic bronchoscopy for lung mass evaluation. Bacterial and fungal culture was performed with conventional media used in clinical microbiology laboratories. On an average, 20 isolated colonies were picked from each agar plate and identified by MALDI-TOF MS. Microbiome analysis using 16S rRNA NGS was conducted for comparison. RESULTS: Streptococcus spp. and Neisseria spp. were most frequently cultured from the BAL fluid samples. In two samples, Enterobacteriaceae grew predominantly on MacConkey agar. Actinomyces and Veillonella spp. were commonly identified anaerobes; gut bacteria, such as Lactobacillus, Bifidobacterium, and Clostridium, and fungi were also isolated. NGS revealed more diverse bacterial communities than culture, and Prevotella spp. were mainly identified solely by NGS. Some bacteria, such as Staphylococcus spp., Clostridium spp., and Bifidobacterium spp., were identified solely by culture, indicating that culture may be more sensitive for detecting certain bacteria. CONCLUSIONS: Culture and NGS of BAL fluid samples revealed common bacteria with some different microbial communities. Despite some limitations, culture combined with MALDI-TOF MS might play a complementary role in microbiome analysis using 16S rRNA NGS.


Subject(s)
Actinomyces , Agar , Bacteria , Bifidobacterium , Bronchoalveolar Lavage Fluid , Bronchoalveolar Lavage , Bronchoscopy , Clostridium , Enterobacteriaceae , Fungi , Humans , Lactobacillus , Lung , Mass Spectrometry , Microbiota , Neisseria , Prevotella , Respiratory System , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Staphylococcus , Streptococcus , Veillonella
SELECTION OF CITATIONS
SEARCH DETAIL