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We aimed to evaluate the performance of ceiling-mounted UV-C lamps. This study was conducted in an empty room with UV-C lamps in the biocontainment unit of a tertiary care hospital in South Korea. Each pathogen (Staphylococcus aureus , Escherichia coli , Candida krusei , Bacillus cereus , and Mycobacterium peregrinum) was inoculated on blood agar plates and placed in 20 selected places from the UV-C lamp, and irradiation was applied for 15 min. As a control group, the bacterial solution was diluted 10,000 times and UV was not applied. A mean ± SD of 5.95 ± 0.91 log reduction was observed with UV irradiation compared with the control. The log reduction was greatest for S. aureus [median, 7.05 (IQR, 6.49–7.26)] and least for M. peregrinum [median, 4.88 (IQR, 4.58–5.24)]. The degree of log reduction was inversely proportional to the square of the distance from the UV-C lamp (R2 = -0.12, P <.001). In this study, ceiling-mounted UV-C demonstrated effective disinfection of at least 4-log reduction of the test organisms within a 4-m distance. Mounted UV-C lighting is a considerable option for improving surface disinfection. • Mounted ultraviolet (UV)-C lamps require no separate space and labor to transport. • Mounted UV-C lamps were installed in patients' rooms in the biocontainment units. • Ceiling-mounted UV-C lamps demonstrated effective disinfection within 4 m. • Mounted UV-C disinfection is simple and effective against various organisms. [ABSTRACT FROM AUTHOR]

• Data about symptoms and viral kinetics of omicron BA.5 is lacking. • We thus compared the symptoms and viral kinetics between SARS-CoV-2 omicron BA.1/BA.2 and omicron BA.5. • Patients with omicron BA.5 had more severe initial symptoms but exhibited shortened viable viral shedding period than those with omicron BA.1/BA.2. • This finding provides evidence for the current CDC guideline about isolation period for patients with SARS-CoV-2 in omicron BA.5 era. [ABSTRACT FROM AUTHOR]

• Immunocompromised patients with COVID-19 shed viable virus for median 4 weeks. • B-cell depleting therapy increases the risk of prolonged viable viral shedding. • Vaccination shortens the viable virus shedding in immunocompromised patients. [ABSTRACT FROM AUTHOR]

• Multi-drug resistant organisms (MDRO) were isolated from 8.6% of COVID-19 pneumonia. • MDROs were detected from 28% (13/47) among patients with culture data. • Long-term care facility stay was a risk factor for isolation of resistant organisms. • Corticosteroids use in COVID-19 may increase the risk of bacterial co-infection. • Strict infection prevention strategies may be needed in patients with risk factors. Superimposed multi-drug resistant organisms (MDROs) co-infection can be associated with worse outcomes in patients with severe coronavirus disease 2019 (COVID-19), even if these patients were managed with strict airborne and contact precautions. Identifying risk factors for isolation of MDROs is critical to COVID-19 treatment. All eligible adult patients with confirmed COVID-19 pneumonia from 10 hospitals in the Republic of Korea between February 2020 and May 2020 were retrospectively enrolled. Using this cohort, epidemiology and risk factors for isolation of MDROs were evaluated. Of 152 patients, 47 with microbial culture results were included. Twenty isolates of MDROs from 13 (28%) patients were cultured. Stenotrophomonas maltophilia (5 isolates) was the most common MDRO, followed by methicillin-resistant staphylococcus aureus (4 isolates). MDROs were mostly isolated from sputum samples (80%, 16/20). The median time from hospitalization to MDRO isolation was 28 days (interquartile range, 18-38 days). In-hospital mortality was higher in patients with MDRO isolation (62% vs 15%; P =.001). Use of systemic corticosteroids after diagnosis of COVID-19 (adjusted odds ratio [aOR]: 15.07; 95% confidence interval [CI]: 2.34-97.01; P =.004) and long-term care facility (LTCF) stay before diagnosis of COVID-19 (aOR: 6.09; 95% CI: 1.02-36.49; P =.048) were associated with MDRO isolation. MDROs were isolated from 28% of COVID-19 pneumonia patients with culture data and 8.6% of the entire cohort. Previous LTCF stay and adjunctive corticosteroid use were risk factors for the isolation of MDROs. Strict infection prevention strategies may be needed in these COVID-19 patients with risk factors. [ABSTRACT FROM AUTHOR]

• Early-onset tuberculosis occurred in 11 patients with posttransplant tuberculosis (12.1%). • Early-onset tuberculosis was associated with a pretransplant tuberculosis history. • Thorough screening test should be performed for patients with a pretransplant tuberculosis history. We encountered some cases of early-onset tuberculosis (TB) after liver transplant (LT), leading to further transmission to other immunocompromised patients. Therefore, we investigated the clinical characteristics and risk factors of early-onset TB after LT. All adult patients with TB after LT from 1996 to 2019 were retrospectively enrolled. Our hospital did not screen for latent TB infection (LTBI) in LT recipients because of concerns regarding the potential hepatotoxicity of anti-TB medication. Patients were categorized into 2 groups based on the TB onset time after LT: early-onset TB (≤2 months) and late-onset TB (>2 months). Of 4301 LT recipients, 91 patients developed TB after LT (2.1%). The median time from LT to TB development was 9.4 months. Of these 91 patients, 11 were classified as having early-onset TB (12.1%). Patients with early-onset TB had a greater pretransplant TB history than patients with late-onset TB (36.4% vs 11.3%, P =.048). This unusual early-onset TB was more common in patients with a pretransplant TB history, suggesting the possibility of missed TB or full manifestation of the indolent course of TB after LT. Therefore, LT recipients with a pretransplant TB history should undergo thorough screening for active TB and consider prophylaxis. [ABSTRACT FROM AUTHOR]

Objectives: We evaluated the effectiveness of IGRA-based isoniazid (INH) treatment with the diagnostic value of quantitative IGRA titer for post-transplant tuberculosis (TB) in kidney transplant (KT) recipients.Methods: All adult KT recipients were enrolled from January 2014 to December 2017. The development of TB after KT was observed, stratified by quantitative IGRA results as well as by IGRA results with/without INH treatment.Results: Of 1150 KT recipients, 322 (28%) revealed positive IGRA results (≥0.35 IU/mL) and 12 (1.0%) developed TB. Seven (3.2%) of 217 patients with positive IGRA without INH developed TB, whereas none of 105 patients with positive IGRA with INH developed TB (rate difference -1616 per 100,000 person-years, P = 0.016) and 5 (0.6%) of 828 patients with negative or indeterminate IGRA developed TB (rate difference -1388 per 100,000 person-years, P<0.001). Among the 217 positive IGRA patients without INH, 6 (6.4%) of 94 patients who had positive IGRA titer>2.96 IU/mL developed TB, whereas one (0.8%) of 123 patients who had positive IGRA titer≤2.96 IU/mL developed TB (rate difference 2964 per 100,000 person-years, P = 0.017).Conclusions: IGRA-based INH treatment with risk stratification by quantitative IGRA results appears to be effective to prevent the development of TB in KT recipients. [ABSTRACT FROM AUTHOR]

Occurrence of typhoons accompanied by heavy precipitation has increased for the past 40 years in northeast Asia. To elucidate the impact of three consecutive typhoon-induced heavy rainfall events and resultant freshwater runoff on the partitioning of organic carbon (C org) oxidation and nutrient dynamics, we investigated the geochemical constituents, the rate of anaerobic C org oxidation, sulfate reduction (SR), iron reduction (FeR) and P speciation in the intertidal mud flat of the Han River estuary, Yellow Sea. C org oxidation by SR and FeR and their metabolic products (∑CO 2 , NH 4 +, H 2 S, Fe2+) decreased significantly (P < 0.05) during and immediately after the heavy rainfall. Additional mesocosm experiments demonstrated that potential N 2 production rates increased up to 2.4 times with increased nitrate concentrations during freshwater runoff. The results suggest that denitrification becomes a significant C org oxidation pathway substituting for SR during high-nitrate freshwater runoff, which may remove substantial portion of the N introduced into the estuary. P speciation analysis further revealed that the concentrations of iron bound P decreased by 2.2 fold during the heavy rainfall compared to that measured before the rainfall. The results suggest that an excess supply of riverine Si keeps P from binding to Fe, thereby stimulating P release. Taking projections of enhanced rainfall events in the future into account, our results suggest that the intensified storm events and resultant riverine runoff induces a shift of C org oxidation pathways in the sediments, which ultimately alters C-N-P-S-Fe dynamics and may deepen N-limiting conditions in coastal ecosystems of the Yellow Sea. Unlabelled Image • Impact of typhoon-induced rainfall and freshwater runoff on sediment biogeochemistry • Carbon oxidation by sulfate- and iron reduction decreased with freshwater runoff • N 2 emission by denitrification increased with the runoff of high nitrate freshwater • Iron bound P decreased during the freshwater runoff containing high silicate • Rainfall and freshwater runoff alter C-N-P-S-Fe dynamics in coastal ecosystems. [ABSTRACT FROM AUTHOR]

Abstract In this study, thermotropic liquid crystal polymer (LCP)-based hybrid materials with various carbon fiber (CF) and polyphenylene sulfide (PPS) contents were developed to replace the heavy metal brackets used for liquid crystal displays (LCDs) in thin, light mobile devices. To determine the physical properties of the composite, several characterization methods, including mechanical, thermal, and morphological tests, were used. As the CF content increases, the tensile and flexural moduli also increase because of the high modulus values of CF. However, some strength-related properties, such as the tensile, flexural, and impact strength, decrease because of the lack of interfacial compatibility between the CF and matrix polymers. Additionally, as the thickness of the LCP-based hybrid material decreases, the flexural strength and flexural modulus increase because of the highly oriented characteristics of LCPs at the surface. To improve the interfacial strength between the CF and LCP, epoxy is a good compatibilizer. In addition, PPS can be used to reduce the weld line formation of LCP and improve the processability of LCP-based hybrid materials with high CF contents. [ABSTRACT FROM AUTHOR]

Objectives: The IFN-γ-release assay (IGRA) cannot differentiate active tuberculosis (TB) from latent TB infection (LTBI). We hypothesized that the TNF-α-release assay (TARA) combined with IGRA might discriminate active TB from not active TB without LTBI.Methods: Adult patients with suspected TB, and with unrelated diseases such as herpes zoster as controls, were enrolled in an intermediate TB-burden country. Patients with confirmed or probable TB were regarded as active TB, and patients with not active TB were further classified as those having not active TB with and without LTBI based on IGRA results. The IGRA and TARA by using ELISPOT assays were performed on peripheral mononuclear cells.Results: Thirty six patients with active TB and 53 patients including 18 not active TB with LTBI and 35 not active TB without LTBI were finally included. The sensitivity and specificity of the IGRA for those patients found to have active TB were 94% (CI, 80-99) and 66% (CI 52-78), respectively. Combining the IGRA and the TARA substantially increased the specificity for active TB (93%, CI, 82-98; P = 0.001) compared with the IGRA only, without compromising sensitivity (89%, CI, 73-96; P = 0.67).Conclusions: Combining the IGRA and TARA appears to be useful for diagnosing active TB. [ABSTRACT FROM AUTHOR]

In order to understand the characteristics and dynamics of dissolved organic matter (DOM) in the sediment of rivers affected by impoundments, we examined the vertical profiles and the benthic fluxes of DOM in four different core sediments located at upstream sites of weirs in major rivers of South Korea. In three out of four sites, exponential accumulation of dissolved organic carbon (DOC) with depth was observed with the signature of seasonal variability. Except for the site displaying a below-detection limit of Fe(II), the general accumulation trends of DOC with depth was concurrent with the increases of Fe(II) and NH 4 + and the decrease of PO 4 3- , signifying a close linkage of the DOM dynamics with anaerobic respiration via iron reduction, an important early diagenesis pathway. The estimated benthic fluxes from the cores revealed that the sediments likely serve as DOC, chromophoric DOM (CDOM), and fluorescent DOM (FDOM) sources to the overlying water. The benthic effluxes based on DOC were comparable to the ranges previously reported in lake and coastal areas, and those of CDOM and FDOM showed even higher levels. These findings imply that impoundment-affected river systems would change the DOM composition of the overlying water, ultimately influencing the subsequent water treatment processes such as disinfection byproducts production and membrane fouling. A simple mass balance model indicated that the impoundment-affected river sediments may operate as a net carbon sink in the environments due to a greater extent of sedimentation compared to the estimated benthic efflux and sediment biological respiration. [ABSTRACT FROM AUTHOR]

We investigated bacterial production (BP) and respiration (BR), as well as the physico-chemical properties of the water column, to elucidate the effect of upwelling on heterotrophic bacterial metabolic activities and growth efficiency (BGE) in July 2012 and May 2013 in the Ulleung Basin (UB), East/Japan Sea. The upwelled conditions were characterized by higher chlorophyll- a (Chl- a ) concentrations resulting from the upward shift of the nitracline compared to that of the non-upwelled condition. Analyses of the size fractions of Chl- a and pigment composition revealed that large size phytoplankton (> 20 µm), mainly consisting of diatoms, appeared to be the major phytoplankton component. BP and BR were significantly correlated with Chl- a ( P < 0.001), but the correlations with temperature were not significant ( P > 0.05). These results suggest that bacterial metabolic activities are stimulated by the availability of organic resources enhanced by upwelling in the UB. Further statistical analysis showed that the difference in BP and BGE with variations in upwelling intensity were significant ( P = 0.018 for BP, P = 0.035 for BGE), but the difference in BR was not significant ( P = 0.321). These results suggest that metabolic energy is partitioned more for BP under a strong upwelling condition, i.e. high nutrient and Chl- a conditions. In contrast, the energy generated via respiration was partitioned more for maintaining metabolism rather than for biomass production under weakly or non-upwelled conditions, i.e. stratified and low Chl- a conditions. Overall, our results suggest that any changes in upwelling intensity would significantly affect the carbon cycle associated with the fate of primary production, and the role of the microbial loop in the UB where changes in the intensity and frequency of upwelling associated with climatic changes are in progress. [ABSTRACT FROM AUTHOR]

We investigated environmental impact of large-scale dyke on the sediment geochemistry, sulfate reduction rates (SRRs), sediment oxygen demand (SOD) and potential contribution of benthic nutrient flux (BNF) to primary production in the Yeongsan River estuary, Yellow Sea. The sediment near the dyke (YE1) with high organic carbon (C org ) content (> 4%, dry wt.) was characterized by extremely high SOD (327 mmol m − 2 d − 1 ) and SRRs (91–140 mmol m − 2 d − 1 ). The sulfate reduction accounted for 73% of C org oxidation, and was responsible for strikingly high concentrations of NH 4 + (7.7 mM), PO 4 3 − (67 μM) and HS − (487 μM) in pore water. The BNF at YE1 accounted for approximately 200% of N and P required for primary production in the water column. The results present one of the most extreme cases that the construction of an artificial dyke may have profound impacts on the biogeochemical and ecological processes in coastal ecosystems. [ABSTRACT FROM AUTHOR]

This paper reports the development of a pH-responsive molecular pattern that shows specific and selective affinity for particular host-guest interactions, and its use as a pH fluorescent sensor. The pH-responsive boronate ester is formed via interactions between the diol group of β-cyclodextrin (CD) and phenylboronic acid of poly(ethylene glycol), and is strategically designed to allow reversible formation of a molecular lining pattern. Printing on a versatile substrate provides a method to monitor the positioning of different molecules by using a pH-responsive boronate ester, allowing specific host-guest interactions on any surface. Confocal laser scanning microscopy, fluorescence spectroscopy, and 1 H NMR results indicate that the assembled CD monolayer can be removed by washing with an acidic pH buffer, demonstrating the presence of a boronate ester connective bridge, which is acid labile. Therefore, visualization of the pH-responsive fluorescence sensor using a rhodamine-CD complex allows straightforward discrimination between different molecules on any substrate, thus facilitating application of this sensor in clinical diagnostics and environmental monitoring. [ABSTRACT FROM AUTHOR]

Objectives: Early diagnosis and treatment of tuberculous meningitis (TBM) is essential for a positive outcome, but sensitive, specific, and rapid diagnostic tests for TBM are lacking. We evaluated the diagnostic utility of enzyme-linked immunosorbent spot (ELISPOT) assays in HIV-uninfected patients with suspected TBM.Methods: All HIV-uninfected patients with suspected TBM were prospectively enrolled at a tertiary care hospital in an intermediate TB-burden country, during a 6-year period. ELISPOT assays were performed on peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid-mononuclear cells (CSF-MC).Results: Of the 276 evaluable patients, 90 (33%) were classified as having TBM (30 definite cases, 19 probable, and 41 possible), and 186 (67%) as having non-TBM. When comparing definite TBM versus non-TBM, the sensitivity and specificity of the PBMC ELISPOT assay (≥6 spots; manufacturer's recommended cut-off) for diagnosing TBM were 96% (95% CI, 82-100) and 58% (95% CI, 50-66), respectively. The CSF-MC ELISPOT assay (≥38 spots; receiver operating characteristic [ROC]-derived cut-off) was a useful rule-in test with specificity of 95% (96% CI, 90-98). Its sensitivity was 68% (95% CI, 45-86), which was superior those of AFB smear microscopy (14%; P < 0.001) and CSF Mycobacterium tuberculosis PCR (41%; P = 0.07). Combining this assay with M. tuberculosis PCR, clinical score, and both together increased sensitivity to 86%, 91%, and 95%, respectively, while retaining about 95% specificity.Conclusions: The CSF-MC ELISPOT assay appears to be a rapid and accurate rule-in test for the diagnosis of TBM and a useful adjunct for diagnosing TBM in HIV-uninfected patients. [ABSTRACT FROM AUTHOR]

We investigated rates of total oxygen uptake (TOU) sulfate reduction (SRR), and benthic nutrient flux (BNF) in sediments of polynya (730–825 m water depth), ice shelf (1064 m water depth), and marginal sea–ice zone (530 m water depth) to evaluate the role of benthic mineralization in degrading organic material produced by primary production in the Amundsen Sea polynya (ASP), Antarctica. Despite high primary production (110 mmol C m −2 d −1 ) in the water column, benthic carbon mineralization in the ASP (average, 2.1±0.3 mmol C m −2 d −1 ) was strikingly lower than in other less productive polar regions, accounting for only 1.9% of primary production. Low sediment accumulation rates (0.18–0.20 cm yr −1 ) and sinking fluxes of organic matter likely caused the low oxygen consumption rates (2.44–3.11 mmol m −2 d −1 ) and low effluxes of dissolved inorganic nitrogen (0.12–0.13 mmol m −2 d −1 ) and phosphate (0.017–0.018 mmol m −2 d −1 ) in the ASP. Carbon oxidation by sulfate reduction (0.11–0.19 mmol C m −2 d −1 ) comprised only 10% of total benthic mineralization, indicating that anaerobic C oxidation plays a minor role in total C oxidation. Our results, including low sediment accumulation rates and benthic metabolic rates, suggest that most organic carbon produced by Phaeocystis blooms would be respired to CO 2 in the water column, and thus the organic carbon reaching the sediment is not adequate to stimulate benthic metabolism in the ASP. [ABSTRACT FROM AUTHOR]

We investigated the heterotrophic bacterial biomass and production in February 2012, in four habitats (a polynya, sea-ice zone, ice shelf, and the open sea) in the Amundsen Sea to determine the spatial distribution, controlling factors, and ecological role of the bacteria during a late phytoplankton bloom by Phaeocystis antarctica . Bacterial abundance (BA) and production (BP) were highest at the center of the polynya, and both were significantly correlated with phytoplankton biomass. BP accounted for average 17% of the organic carbon produced by phytoplankton primary production (PP), which is higher than the average BP:PP ratio reported in most open ocean. The abundance of heterotrophic nanoflagellates (HNF) was correlated with the BA, and the average bacteria:HNF ratio (260) was lower than the values reported in most marine environments (400–1000), including the Ross Sea Polynya (800). Evidence for a tight coupling of bacteria and phytoplankton activities on the one hand and intense HNF grazing on bacteria on the other could be found in the high BP:PP and low bacteria:HNF ratios, respectively. Interestingly, these data were accompanied by low particulate carbon export fluxes measured during the late Phaeocystis bloom. Together, these results indicated that the microbial loop plays a significant role in the biogeochemical carbon cycle and food web processes in the Amundsen Sea Polynya. [ABSTRACT FROM AUTHOR]

Summary Objectives Clinical and radiologic deterioration is sometimes observed during neutrophil recovery in patients with invasive pulmonary aspergillosis (IPA). This deterioration can be caused by immune reconstitution inflammatory syndrome (IRIS) as well as by progression of the IPA. However, there is limited data on IRIS in neutropenic patients. Methods Over a 6-year period, adult patients with neutropenia who met the criteria for probable or proven IPA by the revised EORTC/MSG definition were retrospectively enrolled. IRIS was defined as de novo appearance or worsening of radiologic pulmonary findings temporally related to neutrophil recovery, with evidence of a decrease of 50% in serum galactomannan level. Results Of 153 patients, 36 (24%, 95% CI 18%–31%) developed IRIS during neutrophil recovery. More of these patients received voriconazole than did those with non-IRIS (42% vs. 25%, P = 0.05). Thirty- and ninety-day mortalities were lower in the patients with IRIS than in those with non-IRIS (11% vs. 33%, P = 0.01, and 33% vs. 58%, P = 0.01, respectively). Conclusion IRIS is relatively common among neutropenic patients with IPA, occurring in about one quarter of such patients. It is associated with voriconazole use and has a good prognosis. [ABSTRACT FROM AUTHOR]

Summary Objectives A recently developed RD-1 gene-based assay for diagnosing tuberculous peritonitis (TBP) has given promising results. We therefore created a clinical algorithm for differentiating TBP from other diagnoses using peripheral blood and peritoneal fluid mononuclear cells (PBMC/PF-MC) along with conventional tests. Methods All adult patients with suspected TBP in whom enzyme-linked immunosorbent spot (ELISPOT) assays were performed both on PBMC and PF-MC were prospectively enrolled over a 6-year period. Confirmed TBP with positive cultures or Mycobacterium tuberculosis PCR, probable TBP with PF changes consistent with TBP, caseating granuloma, and a successful response to anti-TB therapy, as well as possible TBP without exclusion of TBP, were each defined. Results A total of 74 patients were enrolled. Of these, 45 (61%) (19 confirmed, 16 probable, and 10 possible) were classified as TBP. The other 29 (39%) patients were classified as not TB. The sensitivity and specificity, respectively, of the tested methods for diagnosing TBP were as follows: PBMC ELISPOT (≥6 spots), 84% and 59%; PF-MC ELISPOT (≥6 spots), 87% and 86%; PF-MC/PBMC ratio (≥3), 69% and 97%; and PF-ADA level (≥21 U/L), 82% and 79%. The areas under the ROC curves were as follows: PF-MC ELISPOT, 0.90; PF-MC/PBMC ratio, 0.82; PBMC ELISPOT, 0.80; and PF-ADA, 0.80, respectively. When a 2-step algorithm (‘PBMC ELISPOT ≥6 spots or PF-ADA ≥21 U/L’ as a rule-out test and ‘PF-MC/PBMC ratio ≥3’ as a rule-in test) was applied, 67% (30/45) of the patients with TBP were accurately classified without undergoing invasive procedures. Conclusions A 2-step algorithm using the PBMC/PF-MC ELISPOT assays and PF-ADA appears to be a promising rapid and non-invasive approach for diagnosing TBP. [ABSTRACT FROM AUTHOR]

The small fuel cell is being researched as an alternative power source to the Li-ion battery in mobile phone. In this paper, a direct hydrogen fuel cell system which powers a mobile phone without a supplementary battery is compactly integrated below 25 ml volume at the backside of the phone. The system consists of a small (8 ml) metal hydride hydrogen storage tank with 4 L hydrogen storage or an energy density of ∼640 W h/L, a thin air-breathing planar polymer electrolyte membrane fuel cell (PEMFC) stack (13.44 cm 2 × 3 mm for a volumetric power density of 335 W/L), miniature pressure regulator, and a high efficiency DC–DC voltage converting circuitry. The hydrogen storage tank is packed with the AB 5 type metal hydride alloy. The eight-cell air-breathing planar stack (8 ml) is very thin (3 mm) due to a thin flexible printed circuit board current collectors as well as a unique riveting assembly and is capable of a robust performance of 2.68 W (200 mW/cm 2 ). A miniature pressure regulator is compact with fluidic and electrical connections within 4 ml. A miniature DC–DC voltage converter operates at an overall efficiency of 90%. Consequently, the estimated energy density of a fully integrated fuel cell system is 205 W h/L (70.5 W h/kg). [ABSTRACT FROM AUTHOR]

Summary: Objective: To evaluate the clinical characteristics and outcomes of patients with hematogenous vertebral osteomyelitis (HVO) caused by gram-negative bacteria (GNB). Methods: We conducted a retrospective chart review of adult patients with HVO from three tertiary-care hospitals over a 7-year period. Results: Of the 313 microbiologically diagnosed HVO cases, GNB was responsible for 65 (20.8%) cases. Compared with patients with MSSA HVO, patients with GNB HVO were more likely to be female (P = 0.03) and have diabetes (P = 0.03), but less likely to have epidural abscess (P = 0.02) and paravertebral abscess (P = 0.003). Clinical outcomes were similar between the GNB and MSSA groups, including in-hospital mortality (4.6% vs. 7.8%; P = 0.53), recurrence (9.7% vs. 4.3%; P = 0.20), and sequelae (31.7% vs. 32.2%; P = 0.95). Among GNB-infected patients, recurrence rates differed according to the total duration of antibiotic treatment: 40.0% (4–6 weeks), 33.3% (6–8 weeks), and 2.1% (≥8 weeks) (P = 0.002). Conclusions: GNB HVO was responsible for 20.8% of adult cases of HVO. Despite some differences in clinical and radiological presentation, clinical outcomes were similar between GNB and MSSA HVO. Antibiotic therapy for ≥8 weeks may benefit patients with GNB HVO. [Copyright &y& Elsevier]

Summary: Objective: To evaluate the clinical characteristics and therapeutic outcomes of patients with hematogenous vertebral osteomyelitis (HVO) caused by methicillin-resistant Staphylococcus aureus (MRSA). Methods: We performed a cohort study of adult patients diagnosed with S. aureus HVO at a tertiary-care hospital over a 7-year period. Results: Of the 139 patients with S. aureus HVO, MRSA caused 62 (44.6%) cases. In multivariate analysis, compared with methicillin-susceptible S. aureus (MSSA), MRSA was associated with a higher risk of persistent bacteremia (≥7 days) (8.40 fold; P < 0.001) and relapse (4.83 fold; P = 0.03), and increased hospital stay (1.69 fold; P = 0.001). Among the MRSA cases, relapse rates differed according to duration of antibiotics: 41.7% (4–6 weeks), 25.0% (6–8 weeks), and 5.6% (≥8 weeks) (P = 0.007). Bacteremia was more likely to persist for ≥7 days in patients with an initial vancomycin trough <15 mg/L than in those with an initial trough ≥15 mg/L (79.3% vs. 20.0%; P = 0.001). Conclusions: MRSA HVO was associated with more frequent persistent bacteremia (≥7 days) and relapse, and longer hospital stay compared to MSSA HVO. Antibiotic therapy for ≥8 weeks and targeting a vancomycin trough of ≥15 mg/L may be benefit patients with MRSA HVO. [Copyright &y& Elsevier]