Treatment of medical device-related infections is challenging and recurrence is common. The main reason for this is that microorganisms adhere to the surfaces of medical devices and enter into a ...biofilm state in which they display distinct growth rates, structural features, and protection from antimicrobial agents and host immune mechanisms compared with their planktonic counterparts. This article reviews how microorganisms form biofilms and the mechanisms of protection against antimicrobial agents and the host immune system provided by biofilms. Also discussed are innovative strategies for the diagnosis of biofilm-associated infection and novel approaches to treatment and prevention of medical device-associated infections.
Nontuberculous mycobacteria (NTM) diseases mainly manifest as pulmonary illnesses, but 20 -30% of NTM isolates originate from extrapulmonary diseases. These diseases cause a variety of clinical ...syndromes, including skin and soft-tissue infections, musculoskeletal infections, lymphadenitis, and disseminated disease. In skin and soft-tissue infections, musculoskeletal infections, prolonged treatment with combinations of antibiotics is effective in the treatment of NTM diseases, with surgery as an important complementary tool. The recommended duration of therapy for skin and soft-tissue infection is usually 2 – 4 months for mild disease and 6 months for severe disease, while treatment of musculoskeletal NTM disease usually requires at least 6 - 12 months. Management options of NTM lymphadenitis include surgical intervention, medical therapy, or observation. Treatment of disseminated NTM disease generally requires 6 to 12 months after immune restoration. However, despite a considerable increase in knowledge about NTM diseases, determining optimal treatment approaches remains a complex and challenging task.
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•SARS-CoV-2 has a high viral load from 5 days before symptoms onset to 10 days after symptoms onset.•rRT-PCR results are converted to negative approximately 3 weeks after the onset of ...symptoms.•Ct values for 6 weeks or longer were repeated negative and positive.•It is necessary to consider the expansion of the scope of epidemiological investigations.•Consider the release of isolation 10 days after symptom onset in limited resource situations.
It is necessary to know the viral kinetics and conduct epidemiological investigations of confirmers to prevent the spread of the new infectious disease COVID-19 to the community. To date, no study has been published on viral kinetics during the preclinical and clinical periods of SARS-CoV-2.
A confirmed case was defined as a patient with positive results by real-time reverse transcription polymerase chain reaction (RT-PCR) assay for SARS-CoV-2. Both specimen types were collected over the whole clinical course in all patients. Asymptomatic patients who had been screened for COVID-19 due to a strong epidemiological link were also enrolled. The study population included 54 hospitalized patients with confirmed COVID-19.
COVID-19 shows a very high viral load on the day of symptom development, which then decreases overall. Rapid viral proliferation was observed 0–5 days before symptoms developed. Cycle threshold (Ct) value was the lowest in the clinical course from 5 days before symptoms to 10 days after symptoms occurred (Ct < 30). The rRT-PCR results were negative approximately 3 weeks after the onset of symptoms. However, there was a continuous pattern that was negative and positive for up to 6 weeks and more.
Considering the characteristic that COVID-19 has a high viral load before symptoms appear, it is necessary to consider to expand the scope of epidemiological investigations. As there is a very low possibility of transmission after 10 days of symptom occurrence, it may be considered to release isolation after 10 days of symptom occurrence in limited resource situations. This study allows for the planning of epidemiological investigations, patient's ward supply, and follow-up of patients through sequential changes in viral loads over the entire clinical course. In addition, it is possible to estimate the clinical time at which the patient is present.
This study aimed to identify the species of
complex (ECC) isolates and compare the genotype, antibiotic resistance, and virulence among them. A total of 183 ECC isolates were collected from patients ...in eight hospitals in South Korea. Based on partial sequences of
and phylogenetic analysis, all ECC isolates were identified as nine species and six subspecies.
was the predominant species (47.0%), followed by
,
,
, and
. Multilocus sequence typing analysis revealed that dissemination was not limited to a few clones, but
subsp.
,
subsp.
, and
formed large clonal complexes. Antibiotic resistance rates were different between the ECC species. In particular,
,
,
, and
isolates were highly resistant to colistin, whereas most
and
isolates were susceptible to colistin. Virulence was evaluated through serum bactericidal assay and the
larvae infection model. Consistency in the results between the serum resistance and the
larvae infection assay was observed. Serum bactericidal assay showed that
,
, and
were significantly more virulent than
and
. In this study, we identified the predominant ECC species in South Korea and observed the differences in antibiotic resistance and virulence between the species. Our findings suggest that correct species identification, as well as continuous monitoring is crucial in clinical settings.
Coronavirus disease 2019 vaccinations for healthcare workers (HCWs) have begun in South Korea. To investigate adverse events (AEs) of the first dose of each vaccine, any symptom was collected daily ...for seven days after vaccination in a tertiary hospital. We found that 1,301 of 1,403 ChAdOx1 nCoV-19 recipients and 38 of 80 BNT162b2 recipients reported AEs respectively (90.9% vs. 52.5%): injection-site pain (77.7% vs. 51.2%), myalgia (60.5% vs. 11.2%), fatigue (50.7% vs. 7.5%), headache (47.4% vs. 7.5%), and fever (36.1% vs. 5%;
< 0.001 for all). Young HCWs reported more AEs with ChAdOx1 nCoV-19 than with BNT162b2. No incidences of anaphylaxis were observed. Only one serious AE required hospitalization for serious vomiting, and completely recovered. In conclusion, reported AEs were more common in recipients with ChAdOx1 nCoV-19 than in those with BNT162b2. However, most of the reported AEs were mild to moderate in severity. Sufficient explanation and preparation for expected AEs required to promote widespread vaccination.
A rapid decline in immunity and low neutralizing activity against the delta variant in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinees has been observed. This study describes ...an outbreak of coronavirus disease 2019 (COVID-19) breakthrough infections caused by the SARS-CoV-2 delta variant in a psychiatric closed ward.
Data from epidemic intelligence service officers were utilized to obtain information regarding demographic, vaccination history, and clinical data along with SARS-CoV-2 PCR test results for a COVID-19 outbreak that occurred in a closed psychiatric ward.
Among the 164 residents, 144 (87.8%) received two doses of vaccines and 137 (95.1%) of them received ChAdOx1 nCoV-19 vaccine. The mean interval between the second vaccination and COVID-19 diagnosis was 132.77 ± 40.68 days. At the time of detection of the index case, SARS-CoV-2 had spread throughout the ward, infecting 162 of 164 residents. The case-fatality ratio was lower than that in the previously reported outbreak before the vaccination (1.2%, 2/162 vs. 6.9%,
= 0.030). Prolonged hospitalization occurred in 17 patients (11.1%) and was less prevalent in the vaccinated group than in the unvaccinated group (8.5% vs. 25.0%,
= 0.040).
The findings of this study highlight that while vaccination can reduce mortality and the duration of hospitalization, it is not sufficient to prevent an outbreak of the SARS-CoV-2 delta variant in the present psychiatric hospital setting.
The epidemiology of bloodstream infection (BSI) is well-established; however, little is known about the contribution of different pathogens to mortality. To understand true burden of BSI, pathogens ...contributing to mortality were investigated and compared according to where the BSI was acquired.
Data from deceased patients in two teaching hospitals in the Republic of Korea were collected. BSI contributing mortality was defined as BSI within 2-weeks before death. Cases were grouped by acquisition sites: community-acquired (CA)-, healthcare-associated (HCA)-, and hospital-acquired (HA)-BSI. Drug resistance, BSI focus, and appropriateness of empirical antimicrobial therapy were also compared.
Among 1849 deceased patients in the hospitals, 280 (15.1%) patients experienced BSI within 2-weeks before death. In all, 71, 53, and 156 patients in the CA-, HCA-, and HA-BSI groups, respectively, with 316 total isolated pathogens were analyzed. The three most common pathogens were Klebsiella pneumoniae (17.1%), Escherichia coli (16.4%), and Staphylococcus aureus (11.4%). While K. pneumoniae and E. coli were the most common pathogens in CA- and HCA-BSI, Acinetobacter baumannii and Candida species were in HA-BSI. 26.3% (41/156) of patients experienced breakthrough HCA-BSI during administration of carbapenem and/or vancomycin. The proportion of central venous catheter-related infection (0%, 3.4% and 28.3%), carbapenem resistant-Gram negative bacilli (0%, 6.9% and 21.9%), and inappropriate empirical antimicrobial therapy (21.1%, 37.7% and 51.9%; all P < 0.001) were more frequently observed in HA-BSI.
The epidemiology of BSI related to mortality had unique characteristics according to the acquisition site. Given the epidemiology of HA-BSI, infection control and antibiotics stewardship programs should be emphasized.
Mass vaccination campaigns are important to control the COVID-19 pandemic, however, adverse events (AEs) contribute to vaccine hesitancy. To investigate and compare early AEs between the BNT162b2 ...mRNA and AZD1222 adenovirus-vectored vaccines, recipients completed daily surveys about local and systemic reactions for 7 days after each dose, respectively. A total of 80 and 1440 healthcare workers received two doses of BNT162b2 and a first dose of AZD1222 vaccines. Any AEs were reported by 52.5% of recipients after the first dose of BNT162b2, by 76.2% after the second dose of BNT162b2, and by 90.9% after the first dose of AZD1222 (p < 0.001). Younger vaccinees had more AEs after the second dose of BNT162b2 and first dose of AZD1222. Sex based differences were only observed in the AZD1222 recipient group. No incidence of anaphylaxis or neurologic AEs were observed. In conclusion, early AEs were mostly mild to moderate in severity and generally transient in both BNT162b2 and AZD1222 groups. Sufficient explanation of the expected AEs of the vaccine would be helpful for wider vaccination.
We investigated the colistin resistance of
Klebsiella pneumoniae
blood isolates from South Korea. Among 252
K. pneumoniae
isolates, only 11 (4.4%) demonstrated colistin resistance, of which, one was ...resistant to all antibiotics but tigecycline. Multilocus sequence typing analysis revealed ten sequence types among the 11 colistin-resistant isolates, indicating independent occurrence of colistin resistance in
K. pneumoniae
. To understand the mechanism of colistin resistance, amino acid variations in PmrAB, PmrD, PhoPQ, and MgrB were investigated. Amino acid substitutions were identified in all the colistin-resistant
K. pneumoniae
isolates. Particularly, extensive alterations in the genes associated with colistin resistance were shared in four colistin-resistant isolates, suggesting recombination between these genes of unrelated isolates. Our results suggest that genetic recombination is responsible for colistin resistance in some
K. pneumoniae
isolates.
Abstract
Background
A loss of muscle mass may be influenced by multiple factors. Insulin sensitivity and metabolic acidosis are associated with muscle wasting and may be improved with potassium ...intake. This study evaluated the association between dietary potassium intake and skeletal muscle mass.
Methods
We performed a cross-sectional study with data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008–2011). Participant’s daily food intake was assessed using a 24-h recall method. Appendicular skeletal muscle mass (ASM) was calculated as the sum of muscle mass in both arms and legs, measured using dual energy X-ray absorptiometry. The skeletal muscle index (SMI) was calculated as ASM divided by height
2
(kg/m
2
). Low muscle mass was defined as a SMI < 7.0 kg/m
2
for men and < 5.4 kg/m
2
for women.
Results
Data from 16,558 participants (age ≥ 19 years) were analyzed. Participants were categorized into quintiles according to their potassium intake. Sex-specific differences were found in the association between potassium intake and muscle mass (
P
Interaction
< 0.001). In men, higher potassium intake was associated with lower odds for low muscle mass; the fully adjusted odds ratios (95% confidence intervals) were 0.78 (0.60–1.03), 0.71 (0.54–0.93), 0.68 (0.51–0.90), and 0.71 (0.51–0.98) for the top four quintiles (referenced against the lowest quintile), respectively. However, this association was attenuated in women after adjusting for total energy intake. Higher potassium intakes were also associated with a greater SMI.
Conclusions
Higher dietary potassium intake decreased the odds of low muscle mass in men but not in women.
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