Genomic epidemiology of hypervirulent carbapenem-resistant Klebsiella pneumoniae at Jinshan local hospital, Shanghai, during 2014-2018

BACKGROUND

Hypervirulent carbapenem-resistant Klebsiella pneumoniae (Hv-CRKP) triggered a significant public health challenge. This study explored the prevalence trends and key genetic characteristics of Hv-CRKP in one Shanghai suburbs hospital during 2014-2018.

METHODS

During five years, Hv-CRKP strains identified from 2579 CRKP by specific PCR, were subjected to performed short- and long-read sequencing technology; epidemiological characteristics, antimicrobial-resistance genes (ARGs), virulence determinants, detailed plasmid profiles and conjugation efficiency were comprehensively investigated.

RESULTS

155 Hv-CRKP and 31 non-Hv-CRKP strains were sequenced. Hv-CRKP strains exhibited significant resistance to six common antibiotic classes (>92%). ST11 steadily increased and became the most prevalent ST (85.2%), followed by ST15 (8.5%), ST65 (2.6%), ST23 (1.9%), and ST86 (0.6%). ST11-KL64 (65.2%) rapidly increased from 0 in 2014 to 93.9% in 2018. blaKPC-2 was the primary carbapenemase gene (97.4%). Other ARGs switched from aac(3)-IId to aadA2 in aminoglycoside and from sul1 to sul2 in sulfanilamide. The time-dated phylogenetic tree was divided into four independent evolutionary clades. Clade 1 and 3 strains were mostly limited in the ICU, whereas Clade 2 strains were distributed among multiple departments. Compared to ybt14 in ICEKp12 in Clade 1, Clade 3 strains harbored ybt9 in ICEKp3 and blaCTX-M-65. Hv-CRKP infected more wards than non-Hv-CRKP and showed greater transmission capacity. Three plasmids containing crucial carbapenemase genes demonstrated their early transmission across China.

CONCLUSION

The Hv-CRKP ST11-KL64 has rapidly replaced ST11-KL47 and emerged as the predominant epidemic subtype in various hospital wards, highlighting the importance of conducting comprehensive early surveillance for Hv-CRKP, especially in respiratory infections.

Isolation and characterization of bacteriophages with activities against multi-drug-resistant Acinetobacter nosocomialis causing bloodstream infection in vivo

BACKGROUND

Acinetobacter nosocomialis (A. nosocomialis) is a glucose non-fermentative, gram-negative bacillus that belongs to the Acinetobacter calcoaceticus-baumannii complex. In recent years, studies have found an increased clinical prevalence of A. nosocomialis. However, given the increasing trend of antibiotic resistance, developing new antibacterial agents is vital. Currently, research regarding bacteriophage therapy against A. nosocomialis is only limited.

METHODS

Two A. nosocomialis bacteriophages, TCUAN1 and TCUAN2, were isolated from sewage. Experiments such as transmission electron microscopy (TEM), host-range analysis, and sequencing were performed to determine their biological and genomic characteristics. TCUAN2 were further subjected to in vivo experiments and their derived-endolysin were cloned and tested against their bacteria host.

RESULTS

Transmission electron microscopy revealed that TCUAN1 and TCUAN2 belong to Myoviridae and Podoviridae, respectively. Both phages show a broad host spectrum and rapid adsorption efficiency. Further biological analysis showed that TCUAN2 possesses a shorter latent period and larger burst size compared to TCUAN1. Because TCUAN2 showed a better antibacterial activity, it was injected into A. nosocomialis-infected mice which resulted in a significant decrease in bacterial load levels in the blood and increased the mice's survival. Finally, genomic analysis revealed that the complete nucleotide sequence of TCUAN1 is 49, 691 bps (containing 75 open reading frames) with a G + C content of 39.3%; whereas the complete nucleotide sequence of TCUAN2 is 41, 815 bps (containing 68 open reading frames) with a G + C content of 39.1%. The endolysin gene cloned and purified from TCUAN2 also showed antibacterial activity when used with a chelator EDTA.

Non-Contrast-Enhanced MR Arteriography of Potential Living-Related Liver Donor: Using Contrast Enhanced CT Arteriography as Standard Reference

BACKGROUND

Contrast-enhanced computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the primary modalities to assess donors' vessels before transplant surgery. Radiation and contrast medium are potentially harmful to donors.

PURPOSE

To compare the image quality and visualization scores of hepatic arteries on CTA and balanced steady-state free-precession (bSSFP) non-contrast-enhanced MRA (NC-MRA), and to evaluate if bSSFP NC-MRA can potentially be a substitute for CTA.

STUDY TYPE

Prospective.

POPULATION

Fifty-six consecutive potential living-related liver donors (30.9 ± 8.4 years; 31 men).

FIELD STRENGTH/SEQUENCE

1.5T; four bSSFP NC-MRA sequences: respiratory-triggered (Inhance inflow inversion recovery [IFIR]) and three breath-hold (BH); and CTA.

ASSESSMENT

The artery-to-liver contrast (Ca-l) was quantified. Three radiologists independently assigned visualization scores using a four-point scale to potential origins, segments, and branches of the hepatic arteries, determined the anatomical variants based on Hiatt's classification, and assessed the image quality of NC-MRA sequences.

STATISTICAL TESTS

Fleiss' kappa to evaluate the readers' agreement. Repeat measured ANOVA or Friedman test to compare Ca-l of each NC-MRA. Friedman test to compare overall image quality and visualization scores; post hoc analysis using Wilcoxon signed-rank test. P-value <0.05 was considered statistically significant.

RESULTS

Inhance IFIR Ca-l was significantly higher than all BH bSSFP Ca-l (0.56 [0.45-0.64] vs. 0.37 [0.29-0.47] to 0.41 [0.23-0.51]). Overall image quality score of BH bSSFP TI1200 was significantly higher than other NC-MRA (4 [4-4] vs. 4 [3 to 4-4]). The median visualization scores of almost all arteries on CTA were significantly higher than on NC-MRA (4 [3 to 4-4] vs. 1 [1-2] to 4 [4-4]). The median visualization scores were all 4 [4-4 ] on Inhance IFIR with >92.3% observed scores ≥3, except the segment 4 branch (3 [1-4], 53.6%). The identification rates of arterial variants were 92.9%-97% on Inhance IFIR.

DATA CONCLUSIONS

Although CTA is superior to the NC-MRA, all NC-MRA depict the donor arterial anatomy well. Inhance IFIR can potentially be an alternative image modality for CTA to evaluate the arterial variants of living donors.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

A highly efficient and accurate method of detecting and subtyping Influenza A pdm H1N1 and H3N2 viruses with newly emerging mutations in the matrix gene in Eastern Taiwan

The rapid identification of Influenza A virus and its variants, which cause severe respiratory diseases, is imperative to providing timely treatment and improving patient outcomes. Conventionally, two separate assays (total test duration of up to 6 h) are required to initially differentiate Influenza A and B viruses and subsequently distinguish the pdm H1N1 and H3N2 serotypes of Influenza A virus. In this study, we developed a multiplex real-time RT-PCR method for simultaneously detecting Influenza A and B viruses and subtyping Influenza A virus, with a substantially reduced test duration. Clinical specimens from hospitalized patients and outpatients with influenza-like symptoms in Eastern Taiwan were collected between 2011 and 2015, transported to Hualien Tzu Chi Hospital, and analyzed. Conventional RT-PCR was used to subtype the isolated Influenza A viruses. Thereafter, for rapid identification, the multiplex real-time RT-PCR method was developed and applied to identify the conserved regions that aligned with the available primers and probes. Accordingly, a multiplex RT-PCR assay with three groups of primers and probes (MAF and MAR primers and MA probe; InfAF and InfAR primers and InfA probe; and MBF and MBR primers and MB probe) was established to distinguish these viruses in the same reaction. Thus, with this multiplex RT-PCR assay, Influenza B, Influenza A pdm H1N1, and Influenza A H3N2 viruses were accurately detected and differentiated within only 2.5 h. This multiplex RT-PCR assay showed similar analytical sensitivity to the conventional singleplex assay. Further, the phylogenetic analyses of our samples revealed that the characteristics of these viruses were different from those reported previously using samples collected during 2012–2013. In conclusion, we developed a multiplex real-time RT-PCR method for highly efficient and accurate detection and differentiation of Influenza A and B viruses and subtyping Influenza A virus with a substantially reduced test duration for diagnosis.

Biological and genomic characterization of two newly isolated Elizabethkingia anophelis bacteriophages

BACKGROUND

Elizabethkingia anophelis is an opportunistic pathogen that infects newborns and immunocompromised patients. Because the infection is associated with high mortality as a result of its intrinsic resistance to antibiotics, alternative treatment methods are needed. Our previous study successfully isolated the world's first E. anophelis phage, TCUEAP1, which showed beneficial protection to E. anophelis-infected mice. More new bacteriophages are needed in order to provide sufficient choices to combat E. anophelis infections.

METHODS

In the current study, two new phages infecting E. anophelis were isolated from wastewater and were designated as TCUEAP2 and TCUEAP3. Further experiments, namely, transmission electron microscopy (TEM), infection assay, host-range analysis, and sequencing were performed to determine their biological and genomic characteristics.

RESULTS

TEM analysis revealed that both TCUEAP2 and TCUEAP3 possess an icosahedral head with a non-contractile tail, and belong to the Siphoviridae family. Further experiments revealed that TCUEAP3 has a longer latent period and higher burst size compared to TCUEAP2. Host range analysis showed that both TCUEAP2 and TCUEAP3 have a narrow host range, infecting only their respective hosts. The genomic size of phage TCUEAP2 was 42,403 bps containing 61 predicted open reading frames (ORFs), whereas the genome size of TCUEAP3 was 37,073 bps containing 40 predicted ORFs.

CONCLUSION

Due to the distinct biological characteristics of TCUEAP2 and TCUEAP3, they may be satisfactory for clinical uses such as preparation of phage cocktails or decontamination in clinical settings.

Preoptimized phage cocktail for use in aerosols against nosocomial transmission of carbapenem-resistant Acinetobacter baumannii: A 3-year prospective intervention study

Using bacteriophages (phages) as environmental sanitizers has been recognized as a potential alternative method to remove bacterial contamination in vitro; however, very few studies are available on the application of phages for infection control in hospitals. Here, we performed a 3-year prospective intervention study using aerosolized phage cocktails as biocontrol agents against carbapenem-resistant Acinetobacter baumannii (CRAB) infection in the hospital. When a CRAB-infected patient was identified in an intensive care unit (ICU), their surrounding environment was chosen for phage aerosol decontamination. Before decontamination, 501 clinical specimens from the patients were subjected to antibiotic resistance analysis and phage typing. The optimal phage cocktails were a combination of different phage families or were constructed by next-evolutionary phage typing with the highest score for the host lysis zone to prevent the development of environmental CRAB phage resistance. The phage infection percentage of the antibiotic-resistant A. baumannii strains was 97.1%, whereas the infection percentage in the antibiotic-susceptible strains was 79.3%. During the phage decontamination periods from 2017 to 2019, the percentage of carbapenem-resistant A. baumannii in test ICUs decreased significantly from 65.3% to 55%. The rate of new acquisitions of CRAB infection over the three years was 4.4 per 1000 patient-days, which was significantly lower than that in the control wards (8.9 per 1000 patient-days) where phage decontamination had never been performed. In conclusion, our results support the potential of phage cocktails to decrease CRAB infection rates, and the aerosol generation process may make this approach more comprehensive and time-saving.

Phage therapy for secondary bacterial infections with COVID-19

With more than 200 million people affected and 4.5 million deaths so far, the coronavirus disease 2019 (COVID-19) pandemic has become one of the greatest disasters in human history. Secondary bacterial infections (SBIs) are a known complication of viral respiratory infections, and are significantly associated with poorer outcomes in COVID-19 patients despite antibiotic treatments. The increasing antimicrobial resistance (AMR) in bacteria and the decreasing options available in our antimicrobial armory worsen this crisis and call for alternative treatment options. As natural killers of bacteria, phages are recognized as promising alternatives to antibiotics in treating pulmonary bacterial infections, however, little is known about their use for treating SBIs during virus pandemics such as COVID-19. This review highlights the situation of SBIs in COVID-19 patients, and the distinct strengths and limitations of phage therapy for their containment.

Pre-optimized phage therapy on secondary Acinetobacter baumannii infection in four critical COVID-19 patients

Phage therapy is recognized as a promising alternative to antibiotics in treating pulmonary bacterial infections, however, its use has not been reported for treating secondary bacterial infections during virus pandemics such as coronavirus disease 2019 (COVID-19). We enrolled 4 patients hospitalized with critical COVID-19 and pulmonary carbapenem-resistant Acinetobacter baumannii (CRAB) infections to compassionate phage therapy (at 2 successive doses of 10⁹ plaque-forming unit phages). All patients in our COVID-19-specific intensive care unit (ICU) with CRAB positive in bronchoalveolar lavage fluid or sputum samples were eligible for study inclusion if antibiotic treatment failed to eradicate their CRAB infections. While phage susceptibility testing revealed an identical profile of CRAB strains from these patients, treatment with a pre-optimized 2-phage cocktail was associated with reduced CRAB burdens. Our results suggest the potential of phages on rapid responses to secondary CRAB outbreak in COVID-19 patients.

Trajectory of Body Mass Index from Ages 2 to 7 Years and Age at Peak Height Velocity in Boys and Girls

OBJECTIVE

To examine the associations between body mass index (BMI) at 2-4 years and 5-7 years and age at peak height velocity (APHV), an objective measure of pubertal timing, among boys and girls from predominantly racial minorities in the US that have been historically underrepresented in this research topic.

STUDY DESIGN

This study included 1296 mother-child dyads from the Boston Birth Cohort, a predominantly Black and low-income cohort enrolled at birth and followed prospectively during 1998-2018. The exposure was overweight or obesity, based on Centers for Disease Control and Prevention reference standards. The outcome was APHV, derived using a mixed effects growth curve model. Multiple regression was used to estimate the overweight or obesity-APHV association and control for confounders.

RESULTS

Obesity at 2-4 years was associated with earlier APHV in boys (B in years, -0.19; 95% CI, -0.35 to -0.03) and girls (B, -0.22; 95% CI, -0.37 to -0.07). Obesity at 5-7 years was associated with earlier APHV in boys (B, -0.18; 95% CI, -0.32 to -0.03), whereas overweight and obesity at 5-7 years were both associated with earlier APHV in girls (overweight: B, -0.24; 95% CI, -0.40 to -0.08; obesity: B, -0.27; 95% CI, -0.40 to -0.13). With BMI trajectory, boys with persistent overweight or obesity and girls with overweight or obesity at 5-7 years, irrespective of overweight or obesity status at 2-4 years, had earlier APHV.

CONCLUSIONS

This prospective birth cohort study found that overweight or obesity during 2-7 years was associated with earlier pubertal onset in both boys and girls. The BMI trajectory analyses further suggest that reversal of overweight or obesity may halt the progression toward early puberty.

The characteristics and genome analysis of vB_ApiP_XC38, a novel phage infecting Acinetobacter pittii

Acinetobacter pittii is an important pathogen causing nosocomial infection worldwide. In this study, a multidrug-resistant A. pittii ABC38 was used as host bacterium to isolate the lytic phage vB_ApiP_XC38. The biological characteristics of vB_ApiP_XC38 were studied and the genome was sequenced and analyzed. vB_ApiP_XC38 belonged to Podoviridae family. The phage had double-stranded genome, which comprised 79,328 bp with 39.58% G+C content displaying very low similarity (< 1% identity) with published genomes of other phages and bacteria. A total of 97 open reading frames (ORFs) were predicted and contained nucleotide metabolism and replication module, structural components module, and lysis module. The ANI, AAI, and phylogenetic analysis indicated that all phages were found distant from vB_ApiP_XC38. Altogether, morphological, genomics, and phylogenetic analysis suggest that vB_ApiP_XC38 is more likely a novel phage of A. pittii.

Masks and closed-loop ventilators prevent environmental contamination by COVID-19 patients in negative-pressure environments

Herein, we report that nosocomial infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be mitigated by using surgical masks and closed looped ventilation for both non-critical and critical patients. These preventive measures resulted in no viral contamination of surfaces in negative pressure environments.

Isolation and Characterization of a New Phage Infecting Elizabethkingia anophelis and Evaluation of Its Therapeutic Efficacy in vitro and in vivo

Elizabethkingia spp. are a group of non-fermentative, Gram-negative, catalase-positive, and non-motile bacilli. They can cause meningitis in neonates and immunosuppressed patients, and lead to high mortality. Considering the rising trend of drug resistance among bacteria pathogens, bacteriophage (phage) therapy is a potential alternative to antibiotics for treating multidrug-resistant bacterial infections. However, so far, no phages specific for Elizabethkingia spp. have been reported. Using a clinically isolated Elizabethkingia anophelis as the host, the phage TCUEAP1 was isolated from wastewater of Hualien Tzu Chi hospital. The phage particle of TCUEAP1 under electron microscopy was revealed to belong to the siphoviridae family, with a head size of 47 nm, and a tail dimension 12 nm in diameter and 172 nm in length. The one-step growth analysis showed that the latent period of TCUEAP1 was about 40 min with a rise period lasting about 20 min, yielding a burst size of approximately 10 PFU/cell. The adsorption rate of TCUEAP1 reached about 70% in 20 min. Using 20 isolates of Elizabethkingia spp. to test the host range of TCUEAP1, it displayed narrow spectrum infecting three strains of E. anophelis, but forming spot lysis on 16 strains. The sequence result showed that the genome of TCUEAP1 is a double-stranded DNA of 49,816 bp, containing 73 predicted open reading frames. Further genomic analysis showed TCUEAP1 to be a new phage with no resemblance to publicly available phage genomes. Finally, in a mouse intraperitoneal infection model, at 6 h after the bacterial injection, TCUEAP1 decreased the bacterial load by fivefold in blood. Also, TCUEAP1 rescued 80% of mice heavily infected with E. anophelis from lethal bacteremia. We hope that the isolation and characterization of TCUEAP1, the first phage infecting Elizabethkingia spp., can promote more studies of the phages targeting this newly emerging bacterial pathogen.

[Association between plasma selenium and the risk of impaired glucose regulation]

Objective: To investigate the association between plasma selenium exposure and the risk of impaired glucose regulation (IGR). Methods: A case-control study was conducted to select IGR patients who were admitted to the outpatient clinic of the Department of Endocrinology to perform oral glucose tolerance test(OGTT) at the Tongji Hospital affiliated to the Tongji Medical College from September 2004 to 2016 as a case group. Participants with normal glucose tolerance recruited from an unselected group of population undergoing routine health examinations in the same hospital were selected as a control group. The control group was matched according to the age (±5 years old) and sex of the case group. The inclusion criteria for subjects recruited were as follows: age ≥30 years, body mass index (BMI) <40 kg/m(2), no history of a diagnosis of IGR or type 2 diabetes, and no history of receiving pharmacological treatment for hyperlipidemia or hypertension. Patients with any clinically systemic disease such as neurological or endocrine disease, acute illness, chronic inflammatory disease or infectious disease were excluded from the study. A total of 1 957 subjects, 897 in the case group and 1 060 in the control group, were included. Questionnaires were used to collect information of all subjects, and peripheral venous blood was collected after fasting and OGTT, respectively. Plasma selenium, fasting blood glucose, blood lipid (total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol) and 2 h OGTT plasma glucose concentration were detected, respectively. The subjects were divided into low, medium and high concentration groups according to the tertiles of plasma selenium concentration in the control group. The multivariate unconditional logistic regression analysis was performed to analyze the association between plasma selenium exposure and IGR. Results: The age (mean±SD) of the case and control group was (53.71±11.38) and (53.95±12.17) years old. The plasma selenium concentration [M (P(25), P(75))] in the case group was 92.81(77.07, 107.05) μg/L, which was significantly higher than the control group [88.73 (77.13, 100.88) μg/L] (P<0.05). The results of multivariate unconditional logistic regression analysis showed that after adjusting for age, sex, BMI, family history of diabetes and hypertension, the risk of IGR was higher in the high-concentration group and the low-concentration group compared with the middle-concentration group, the values of OR (95%CI) were 1.22 (95%CI: 0.94-1.59) and 1.81 (95%CI: 1.42-2.30), respectively. Conclusion: The study suggested a U-shaped association between plasma selenium and IGR.

A surface antigen of Orientia tsutsugamushi activates human monocyte-derived dendritic cells via nuclear factor-kB & p38 mitogen-activated protein kinase pathways

Background & objectives:

Scrub typhus is a chigger-borne disease caused by Orientia tsutsugamushi. The immunological reactions to O. tsutsugamushi infection are not completely understood. In this study, we investigated the response of dendritic cells (DCs) to a major 56-kDa scrub typhus antigen Sta56.

Methods:

Monocyte-derived human DCs were incubated with different concentrations of recombinant Sta56 and analyzed for maturation based on phagocytic capacity, the ability to induce T-cell proliferation, expression of surface markers, cytokine secretion and activation of toll-like receptor (TLR)-dependent signalling pathways.

Results:

Treatment of DCs with Sta56 induced cell surface expression of CD80, CD83, CD86 and MHC Class II increased the production of interleukin-12 (IL-12) p40, IL-12 p70 and IL-10 and decreased DC phagocytic capacity. Furthermore, Sta56 increased the ability of DCs to activate T-cell proliferation and interferon-γ secretion. TLR4-specific antibodies neutralized Sta56-elicited effects on DC maturation, suggesting direct interaction between Sta56 and TLR4. Moreover, Sta56 activated nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK) signalling as evidenced by decrease in Sta56-induced cytokine production and surface marker expression by specific inhibitors helenalin and SB203580, respectively, and increase in IκBα and p38 phosphorylation and NF-κB-DNA binding.

Interpretation & conclusions:

Our results showed that the surface antigen of O. tsutsugamushi activated DCs through interaction with TLR4 and activation of MAPK and NF-κB signalling, suggesting Sta56 as a potential candidate molecule for the development of vaccine against scrub typhus.

Clinical Antibiotic-resistant Acinetobacter baumannii Strains with Higher Susceptibility to Environmental Phages than Antibiotic-sensitive Strains

Antibiotic-resistant Acinetobacter baumannii is associated with nosocomial infections worldwide. Here, we used clinically isolated A. baumannii strains as models to demonstrate whether antibiotic resistance is correlated with an increased susceptibility to bacteriophages. In this study, 24 active phages capable of infecting A. baumannii were isolated from various environments, and the susceptibilities of both antibiotic-sensitive and antibiotic-resistant strains of A. baumannii to different phages were compared. In our study, a total of 403 clinically isolated A. baumannii strains were identified. On average, the phage infection percentage of the antibiotic-resistant A. baumannii strains was 84% (from 81–86%), whereas the infection percentage in the antibiotic-sensitive A. baumannii strains was only 56.5% (from 49–64%). In addition, the risk of phage infection for A. baumannii was significantly increased in the strains that were resistant to at least four antibiotics and exhibited a dose-dependent response (p-trend < 0.0001). Among all of the A. baumannii isolates, 75.6% were phage typeable. The results of phage typing might also reveal the antibiotic-resistant profiles of clinical A. baumannii strains. In conclusion, phage susceptibility represents an evolutionary trade-off in A. baumannii strains that show adaptations for antibiotic resistance, particularly in medical environments that have high antibiotic use.

Application of Bacteriophage-containing Aerosol against Nosocomial Transmission of Carbapenem-Resistant Acinetobacter baumannii in an Intensive Care Unit

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is associated with nosocomial infections worldwide. Here, we used phage as a potential agent to evaluate the efficacy of daily cleaning practices combined with a bacteriophage-containing aerosol against CRAB.

METHODS

A two-phase prospective intervention study was performed at a 945-bed public teaching hospital. From March to December 2013, we performed terminal cleaning using standard procedures plus an aerosol with active bacteriophage in the intensive care units to evaluate the impact on nosocomial incidence density, carbapenem-resistance rates and antimicrobial drug consumption amounts. Patients with culture proven CRAB infection were transferred to the isolation room when the phage aerosol cleaning had been completed.

RESULTS

A total of 264 new acquisitions of CRAB were identified in the intensive care units (191 in the pre-intervention period and 73 in the intervention period). The rates of new acquisitions of CRAB in the intensive care units decreased from 8.57 per 1000 patient-days in the pre-intervention period to 5.11 per 1000 patient-days in the intervention period (p = 0.0029). The mean percentage of resistant isolates CRAB decreased from 87.76% to 46.07% in the intensive care units (p = 0.001). All of the antimicrobials showed a significant reduction in consumption except imipenem.

CONCLUSIONS

The bacteriophage was successful in decreasing the rates of infection caused by CRAB across intensive care units in a large teaching hospital.

Aspirin plus tirofiban inhibit the thrombosis induced by Russell's viper venom

Background

Thrombosis and coagulopathy are the commonest hematological manifestations of envenomation of Russell’s viper venom (RVV). Factor X is activated by a factor X-activating enzyme from Russell’s viper venom (RVV-X) to start the coagulation cascade. We established an animal model with local ischemic effects induced by RVV. We tried to treat RVV envenomation with antiplatelets and anticoagulants without recourse to antivenom.

Methods

RVV was injected into the foot pad of mice. We observed the effects at different intervals and compared local changes in ischemia with drug treatment after 30 min.

Results

A combination of aspirin plus tirofiban could prevent the ischemic change induced by RVV. The antithrombotic effects of single-use of aspirin or tirofiban were better than single-use of heparin or clopidogrel.

Conclusion

The aspirin + tirofiban group had a better outcome with respect to prevention of tissue ischemia and gangrene. This indicates that the activation and aggregation of platelets is the major cause of thrombosis induced by RVV.

Cross-Regulation of Proinflammatory Cytokines by Interleukin-10 and miR-155 in Orientia tsutsugamushi-Infected Human Macrophages Prevents Cytokine Storm

Scrub typhus is caused by the obligate intracellular bacterium Orientia tsutsugamushi. Macrophages are host cells for its replication and clearance. Severe complications in patients are mainly caused by a cytokine storm resulting from overproduction of proinflammatory cytokines; nevertheless, the molecular mechanism for the occurrence remains obscure. Herein, we investigate the interactive regulation of cytokines and micro-RNA (miR) in human macrophages infected with low and high doses of O. tsutsugamushi. During low dose infection, macrophages produce high levels of IL-10 through extracellular signal-regulated kinase activation, which inhibits proinflammatory cytokine production and facilitates pathogen replication. Increasing levels of pathogen results in reduced levels of IL-10, and macrophages begin to generate high levels of proinflammatory cytokines through NF-κB activation. However, during a high dose infection, macrophages produce high levels of miR-155 to slow the proinflammatory response. The extracellular signal-regulated kinase/IL-10 axis suppresses the NF-κB/tumor necrosis factor alpha axis via activation of signal transducer and activator of transcription 3. Both IL-10 and miR-155 inhibit the NF-κB signaling pathway. Furthermore, IL-10 is a potent inhibitor of miR-155. Patients susceptible to a cytokine storm, peripheral blood mononuclear cells showed significantly lower IL-10 and miR-155 responses to O. tsutsugamushi challenge. Thus, IL-10 and miR-155 operate inhibitory mechanisms to achieve a proper defense mechanism and prevent a cytokine storm.

Human adenovirus type 8 epidemic keratoconjunctivitis with large corneal epithelial full-layer detachment: an endemic outbreak with uncommon manifestations

Epidemic viral conjunctivitis is a highly contagious disease that is encountered year-round. The causative agents are mainly adenoviruses and enteroviruses. It occurs most commonly upon infection with subgroup D adenoviruses of types 8, 19, or 37. For common corneal involvement of human adenovirus type 8 epidemic keratoconjunctivitis, full-layer epithelial detachment is rarely seen. Herein, we report three cases of epidemic keratoconjunctivitis during an outbreak which manifested as large corneal epithelial full-layer detachment within a few days. The lesions healed without severe sequelae under proper treatment. The unique manifestation of this outbreak may indicate the evolution of human adenovirus type 8.

Effect of taxane-based neoadjuvant chemotherapy on fibroglandular tissue volume and percent breast density in the contralateral normal breast evaluated by 3T MR

The aim of this study was to evaluate the change of breast density in the normal breast of patients receiving neoadjuvant chemotherapy (NAC). Forty-four breast cancer patients were studied. MRI acquisition was performed before treatment (baseline), and 4 and 12 weeks after treatment. A computer-algorithm-based program was used to segment breast tissue and calculate breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) (the ratio of FV over BV × 100%). The reduction of FV and PD after treatment was compared with baseline using paired t-tests with a Bonferroni-Holm correction. The association of density reduction with age was analyzed. FV and PD after NAC showed significant decreases compared with the baseline. FV was 110.0 ml (67.2, 189.8) (geometric mean (interquartile range)) at baseline, 104.3 ml (66.6, 164.4) after 4 weeks (p < 0.0001), and 94.7 ml (60.2, 144.4) after 12 weeks (comparison with baseline, p < 0.0001; comparison with 4 weeks, p = 0.016). PD was 11.2% (6.4, 22.4) at baseline, 10.6% (6.6, 20.3) after 4 weeks (p < 0.0001), and 9.7% (6.2, 17.9) after 12 weeks (comparison with baseline, p = 0.0001; comparison with 4 weeks, p = 0.018). Younger patients tended to show a higher density reduction, but overall correlation with age was only moderate (r = 0.28 for FV, p = 0.07, and r = 0.52 for PD, p = 0.0003). Our study showed that breast density measured from MR images acquired at 3T MR can be accurately quantified using a robust computer-aided algorithm based on non-parametric non-uniformity normalization (N3) and an adaptive fuzzy C-means algorithm. Similar to doxorubicin and cyclophosphamide regimens, the taxane-based NAC regimen also caused density atrophy in the normal breast and showed reduction in FV and PD. The effect of breast density reduction was age related and duration related.

[Exploring the lived experiences of middle-aged males diagnosed with chronic kidney disease]

BACKGROUND

The majority of studies addressing chronic kidney disease (CKD) have been quantitative. The lived experiences of patients with early stage CKD have not been explored in the literature. Due to the lack of symptoms during the early stages of CKD, the progress of this disease is often ignored.

PURPOSE

This study explores the lived experiences of middle-aged males diagnosed with CKD. Research focuses on the work experiences, interpersonal relationships, and dietary habits of this group.

METHODS

This qualitative study used a narrative research method with purposive sampling. Ten middle-aged male patients were interviewed. We employed the 3 strategies of member checks, peer review, and debriefing in order to enhance the trustworthiness of the data analysis.

RESULTS

Four major themes were identified: (1) keeping the same life pace as usual with concerns of deterioration; (2) continuing to support their family and play the role of father; (3) hoping to participate in family and friend relationships despite the illness; and (4) being challenged to maintain a healthy diet.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

Although the physical status of participants was similar to the general middle-aged adult population, participants were concerned regarding disease deterioration. The results of this study suggest that health professionals: (1) provide appropriate information based on patients' personality, particularly at the first onset or apparent deterioration of the disease; (2) offer specialized healthcare information to patients relevant to their career choices; and (3) understand CKD-patient difficulties in daily life such as eating out habits and challenges faced in maintaining a healthy diet. Results may provide important information to healthcare providers in education planning and implementation and support programs for patients and families.

Potential of bacteriophage ΦAB2 as an environmental biocontrol agent for the control of multidrug-resistant Acinetobacter baumannii

BACKGROUND

Multidrug-resistant Acinetobacter baumannii (MDRAB) is associated with nosocomial infections worldwide. To date, the use of a phage to prevent infections caused by MDRAB has not been demonstrated.

RESULTS

The MDRAB-specific phage ϕAB2 was stable at 4°C and pH 7 in 0.5% chloroform solution, and showed a slight decrease in plaque-forming units (PFU)/ml of 0.3-0.9 log after 330 days of storage. The addition of ϕAB2 at a concentration of at least 10⁵ PFU/ml to an A. baumannii M3237 suspension killed >99.9% of A. baumannii M3237 after 5 min, regardless of A. baumannii M3237 concentration (10⁴, 10⁵, or 10⁶ colony-forming units (CFU)/ml). The addition of ϕAB2 at a concentration of 10⁸ PFU/slide (>10⁷ PFU/cm²) to glass slides containing A. baumannii M3237 at 10⁴, 10⁵, or 10⁶ CFU/slide, significantly reduced bacterial numbers by 93%, 97%, and 99%, respectively. Thus, this concentration is recommended for decontamination of glass surfaces. Moreover, infusion of ϕAB2 into 10% glycerol exhibited strong anti-MDRAB activity (99.9% reduction), even after 90 days of storage. Treatment of a 10% paraffin oil-based lotion with ϕAB2 significantly reduced (99%) A. baumannii M3237 after 1 day of storage. However, ϕAB2 had no activity in the lotion after 1 month of storage.

CONCLUSIONS

Phages may be useful for reducing MDRAB contamination in liquid suspensions or on hard surfaces. Phages may also be inoculated into a solution to produce an antiseptic hand wash. However, the phage concentration and incubation time (the duration of phage contact with bacteria) should be carefully considered to reduce the risk of MDRAB contamination.

Identification and characterisation of the putative phage-related endolysins through full genome sequence analysis in Acinetobacter baumannii ATCC 17978

Acinetobacter baumannii has recently emerged as a major cause of healthcare-associated infections owing to an increase in its antimicrobial resistance to virtually all available drugs. The ability of endolysins (lysozymes) to digest cell walls when applied exogenously to bacterial cells has enabled their use as novel antibacterials. In order to utilise endolysins as a therapeutic alternative to antibiotics, we surveyed the genome sequence of A. baumannii ATCC 17978 and successfully identified two phage-related endolysin genes, A1S_1600 and A1S_2016 (termed lysAB3 and lysAB4, respectively). Following cloning and expression/purification, various antibacterial activities of these two phage-related endolysins were determined in vitro. Zymographic assays showed that only purified LysAB3 could lyse the peptidoglycan of the A. baumannii cell wall. When applied exogenously, both LysAB3 and LysAB4 were active against most Acinetobacter spp. tested but had virtually no activity against other non-Acinetobacter spp. Scanning electron microscopy revealed that exposure to 100μg/mL LysAB3 and LysAB4 for up to 60min caused a remarkable modification of the cell shape of A. baumannii. These results indicate that the genes encoding phage-related endolysins can be readily isolated from the bacterial genome and have potential for the development of novel antimicrobial agents.

Hepatitis B virus surface antigen can activate human monocyte-derived dendritic cells by nuclear factor kappa B and p38 mitogen-activated protein kinase mediated signaling

Hepatitis B virus Ag (HBsAg), a major antigen of hepatitis B virus (HBV), is also a vaccine component for prevention of HBV infection. Dendritic cells (DCs) of HBV carriers reportedly exhibit functional impairment. In this study, the aim was to investigate the effect of HBsAg on activation of human monocyte-derived dendritic cells (MD-DCs), and the subsequent signal transduction pathway. Treatment of MD-DCs with HBsAg resulted in enhanced cell surface expression of cluster of differentiation 80, CD83, CD86 and major histocompatibility complex class II, and increased interleukin (IL)-12 p40, IL-12p70, and IL-10 production. Furthermore, HBsAg treatment of MD-DCs with HBsAg resulted in enhanced T cell-stimulatory capacity and increased T cell secretion of interferon and IL-10. The pathway of MD-DCs activation by HBsAg was further investigated in the present study. Inhibition of nuclear factor (NF)-kappa B (κB) by helenalin and p38 mitogen-activated protein kinase (MAPK) by SB203580 prevented production of IL-12 p40, IL-12 p70, and IL-10. HBsAg also augmented MAPK phosphorylation. Thus, cytokine secretion of human MD-DCs by HBsAg is blocked by inhibition of the NF-κB and p38 MAPK pathways. Likewise, decreased inhibition of kappa B alpha concentrations and MAPK phosphorylation are critical for MD-DC maturation by HBsAg. These findings may provide a strategy for improving the prophylactic and therapeutic efficacy of vaccines and tumor therapies that utilize these pathways.

Involvement of extraneural tissues and upregulation of inducible nitric oxide synthase after experimental infection with rabies virus in BALB/c mice and LEW/SsN rats

Rabies virus can cause fatal encephalomyelitis, but the involvement of extraneural organs has not been well characterized. In this study, we investigated the histopathological changes and the distribution of viral antigens in extraneural organs after pathogenic rabies virus infection in mouse and rat models. In histopathological examination, classical viral encephalitis and rabies-specific Negri body were observed in the brain. In addition to the central nervous system (CNS), inflammatory responses were found in other organs, such as the heart, kidney, liver, and lung. Similarly, immunohistochemical staining and reverse transcription-polymerase chain reaction revealed the presence of rabies virus in the CNS and extraneural tissues. Moreover, macrophages, especially in the lung and heart, were involved in the infection. Transcriptional analyses of the expression of inducible nitric oxide synthase (iNOS) demonstrated that rabies virus potentiated the gene expression of iNOS in the brain, lung, and heart. The immunoreactive iNOS-positive macrophages were detected adjacent to the infection. These results suggest that macrophages are involved in the extraneural infection and the expression of iNOS in macrophages contributes to the formation of tissue inflammation. Our study indicates the involvement of extraneural organs following rabies virus infection, which may aggravate the progression of this deadly disease.

Promoting access to innovation for frail old persons. IAGG (International Association of Gerontology and Geriatrics), WHO (World Health Organization) and SFGG (Société Française de Gériatrie et de Gérontologie) Workshop--Athens January 20-21, 2012

Frailty tends to be considered as a major risk for adverse outcomes in older persons, but some important aspects remain matter of debate.

OBJECTIVES

The purpose of this paper is to present expert's positions on the main aspects of the frailty syndrome in the older persons.

PARTICIPANTS

Workshop organized by International Association of Gerontology and Geriatrics (IAGG), World Health Organization (WHO) and Société Française de Gériatrie et de Gérontologie (SFGG).

RESULTS

Frailty is widely recognized as an important risk factor for adverse health outcomes in older persons. This can be of particular value in evaluating non-disabled older persons with chronic diseases but today no operational definition has been established. Nutritional status, mobility, activity, strength, endurance, cognition, and mood have been proposed as markers of frailty. Another approach calculates a multidimensional score ranging from "very fit" to "severely frail", but it is difficult to apply into the medical practice. Frailty appears to be secondary to multiple conditions using multiple pathways leading to a vulnerability to a stressor. Biological (inflammation, loss of hormones), clinical (sarcopenia, osteoporosis etc.), as well as social factors (isolation, financial situation) are involved in the vulnerability process. In clinical practice, detection of frailty is of major interest in oncology because of the high prevalence of cancer in older persons and the bad tolerance of the drug therapies. Presence of frailty should also be taken into account in the definition of the cardiovascular risks in the older population. The experts of the workshop have listed the points reached an agreement and those must to be a priority for improving understanding and use of frailty syndrome in practice.

CONCLUSION

Frailty in older adults is a syndrome corresponding to a vulnerability to a stressor. Diagnostic tools have been developed but none can integrate at the same time the large spectrum of factors and the simplicity asked by the clinical practice. An agreement with an international common definition is necessary to develop screening and to reduce the morbidity in older persons.

Consistency of breast density measured from the same women in four different MR scanners

PURPOSE

To compare the breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) measured from breast MRI of the same women using four different MR scanners.

METHODS

The study was performed in 34 healthy Asian volunteers using two 1.5T (GE and Siemens) and two 3T (GE and Philips) MR scanners. The BV, FV, and PD were measured on nonfat-suppressed T1-weighted images using a comprehensive computer algorithm-based segmentation method. The scanner-to-scanner measurement difference, and the coefficient of variation (CV) among the four scanners were calculated. The measurement variation between two density morphological patterns presenting as the central type and the intermingled type was separately analyzed and compared.

RESULTS

All four scanners provided satisfactory image quality allowing for successful completion of the segmentation processes. The measured parameters between each pair of MR scanners were highly correlated, with R(2) ≥ 0.95 for BV, R(2) ≥ 0.99 for FV, and R(2) ≥ 0.97 for PD in all comparisons. The mean percent differences between each pair of scanners were 5.9%-7.8% for BV, 5.3%-6.5% for FV, 4.3%-7.3% for PD; with the overall CV of 5.8% for BV, 4.8% for FV, and 4.9% for PD. The variation of FV was smaller in the central type than in the intermingled type (p = 0.04).

CONCLUSIONS

The results showed that the variation of FV and PD measured from four different MR scanners is around 5%, suggesting the parameters measured using different scanners can be used for a combined analysis in a multicenter study.

Familial cases of Henoch-Schönlein purpura in Taiwanese Aborigines

Henoch-Schönlein purpura (HSP) is a disorder whose cause and pathogenesis is unknown; some familial cases of this disease have been reported. The clinical heterogeneity in HSP may be conferred by a number of genetic loci, including the major histocompatibility complex. The racial and genetic factors responsible for the occurrence of the familial cases of HSP in Taiwan are unclear. The purpose of this study was to examine the racial and genetic factors in familial HSP cases in Taiwan. We retrospectively collected the HSP cases in our hospital during 2006 through 2010 and observed that familial HSP cases were only in Taroko Aborigines. Six cases of HSP in 3 Taroko families were found, and their human leukocyte antigens (HLA) were studied in the tissue typing laboratory of our hospital, to determine the possible association with familial HSP cases in Taiwanese Aborigines. Our results suggest an increased frequency of familial HSP cases with HLA-A24 in Taiwanese Taroko Aborigines. We concluded that racial and genetic predisposition was the possible cause for the familial occurrence of and renal involvement in HSP in Taiwanese Aborigines.

Sufficient virus-neutralizing antibody in the central nerve system improves the survival of rabid rats

Background

Rabies is known to be lethal in human. Treatment with passive immunity for the rabies is effective only when the patients have not shown the central nerve system (CNS) signs. The blood–brain barrier (BBB) is a complex functional barrier that may compromise the therapeutic development in neurological diseases. The goal of this study is to determine the change of BBB integrity and to assess the therapeutic possibility of enhancing BBB permeability combined with passive immunity in the late stage of rabies virus infection.

Methods

The integrity of BBB permeability in rats was measured by quantitative ELISA for total IgG and albumin levels in the cerebrospinal fluid (CSF) and by exogenously applying Evans blue as a tracer. Western blotting of occludin and ZO-1, two tight junction proteins, was used to assess the molecular change of BBB structure.

The breakdown of BBB with hypertonic arabinose, recombinant tumor necrosis factor-alpha (rTNF-γ), and focused ultrasound (FUS) were used to compare the extent of BBB disruption with rabies virus infection. Specific humoral immunity was analyzed by immunofluorescent assay and rapid fluorescent focus inhibition test. Virus-neutralizing monoclonal antibody (mAb) 8-10E was administered to rats with hypertonic breakdown of BBB as a passive immunotherapy to prevent the death from rabies.

Results

The BBB permeability was altered on day 7 post-infection. Increased BBB permeability induced by rabies virus infection was observed primarily in the cerebellum and spinal cord. Occludin was significantly decreased in both the cerebral cortex and cerebellum. The rabies virus-specific antibody was not strongly elicited even in the presence of clinical signs. Disruption of BBB had no direct association with the lethal outcome of rabies. Passive immunotherapy with virus-neutralizing mAb 8-10E with the hypertonic breakdown of BBB prolonged the survival of rabies virus-infected rats.

Conclusions

We demonstrated that the BBB permeability was altered in a rat model with rabies virus inoculation. Delivery of neutralizing mAb to the infected site in brain combined with effective breakdown of BBB could be an aggressive but feasible therapeutic mode in rabies when the CNS infection has been established.

Effect of probiotics on allergic rhinitis in Df, Dp or dust-sensitive children: a randomized double blind controlled trial

OBJECTIVE

To study, we examined the effect of Lactobacillus salivarius on the clinical symptoms and medication use among children with established allergic rhinitis (AR).

DESIGN

Double blind, randomized, controlled trial.

SETTING

Hualien Tzu-Chi General Hospital.

METHODS

Atopic children with current allergic rhinitis received 4x10(9) colony forming units/g of Lactobacillus salivarius (n=99) or placebo (n=100) daily as a powder mixed with food or water for 12 weeks. The SCORing Allergic rhinitis index (specific symptoms scores [SSS] and symptom medication scores [SMS]), which measures the extent and severity of AR, was assessed in each subject at each of the visits--2 weeks prior to treatment initiation (visit 0), at the beginning of the treatment (visit 1), then at 4 (visit 2), 8 (visit 3) and 12 weeks (visit 4) after starting treatment. The WBC, RBC, platelet and, eosinophil counts as well as the IgE antibody levels of the individuals were evaluated before and after 3 months of treatment.

RESULTS

The major outcome, indicating the efficacy of Lactobacillus salivarius treatment, was the reduction in rhinitis symptoms and drug scores. No significant statistical differences were found between baseline or 12 weeks in the probiotic and placebo groups for any immunological or blood cell variables.

CONCLUSIONS

Our study demonstrates that Lactobacillus salivarius treatment reduces rhinitis symptoms and drug usage in children with allergic rhinitis.

Molecular characterization of three major outer membrane proteins, TSA56, TSA47 and TSA22, in Orientia tsutsugamushi

Orientia tsutsugamushi (O. tsutsugamushi), the causative agent of scrub typhus, is an obligate intracellular pathogen. Recent studies have demonstrated the complete genome of O. tsutsugamushi. However, the route and detailed molecular mechanism for O. tsutsugamushi to get accessed into mammalian cells remains unclear. In this study, we demonstrated different adhesive properties of three major outer membrane proteins of O. tsutsugamushi, TSA56, TSA47 and TSA22. TSA56 showed higher antibody responses against patient serum samples compared with those of TSA47 and TSA22. In the adhesion assay, TSA56 exhibited a relative higher adhesion to host cells than TSA47 and TSA22, suggesting that TSA56 is the major outer membrane protein required for O. tsutsugamushi adhesion. Furthermore, the antigen domain (AD) I (residues 19-114) corresponding to the extracellular domain of TSA56 demonstrated a relative high antibody response against the patients' sera than the previously reported ADIII (residues 237-366), which has been suggested to facilitate the invasion of O. tsutsugamushi through interaction with fibronectin. Taken together, our results consistently showed that TSA56 of O. tsutsugamushi is important in the adhesion of Escherichia coli (E. coli) transformants to Vero cells. Moreover, in contrast to known ADIII-fibronectin interactions, TSA56-ADI may also play a role in the adhesion and/or invasion of O. tsutsugamushi to its host cells through unidentified receptors. A further study aimed at delineating the receptor of TSA56-ADI during O. tsutsugamushi infection is warranted.

IAGG workshop: health promotion program on prevention of late onset dementia

IAGG, WHO, and SFGG organized a international workshop on Health promotion programs on prevention of late on-set dementia. Thirty world specialists coming from Europe, North America, Asia, South America, Africa and Australia, shared their experience on methods and results of large epidemiological interventions to reduce incidents of dementia or delay its on-set. Chaired by Laura FRATIGLIONI, an expert in Epidemiological studies on dementia issues, the workshop gave opportunity for discussions and controversies about the state-of-the-art. Based on different national and international trials (ADAPT, MAPT, FINGER, GUDIAGE, GEM etc) the questions remained opened for different aspects of methodology, the choice of domain or multi domain intervention, the choice and the definition of the target populations, the best age of candidates, the issues related to the discrepancy between late effects, and interventions' duration. We are please to publish in the Journal, the presentations presented to this workshop. These publications will complete previously task force published in the journal in the last two years on methodological issues for Alzheimer's trials including end point, biomarkers, and the experience of past therapeutic trials.

Autonomic dysfunction because of severe tetanus in an unvaccinated child

Tetanus is rare in a country with a national vaccination program. When it does occur, the associated autonomic dysfunction is a challenge for physicians. We report here a case of an unvaccinated 5-year-old boy who suffered from tetanus complicated by autonomic dysfunction, which was successfully controlled by the infusion of magnesium sulfate. This is the first case that demonstrated the therapeutic effect of magnesium sulfate in a child with tetanus. This case highlights the importance of implementing a vaccination program.

Immuno-modulatory activity of Ganoderma lucidum-derived polysacharide on human monocytoid dendritic cells pulsed with Der p 1 allergen

Background

Ganoderma lucidum-derived polysaccharide (PS-G) can rapidly and effectively promote the activation and maturation of immature dendritic cells (DCs), suggesting that PS-G possesses the capacity to regulate immune responses. This study aimed to clarify the immunologic effect of PS-G on monocyte-derived dendritic cells (MD-DCs) from asthmatic children allergic to house dust mites. The MD-DCs were stimulated for 24 h with the related allergen, Der p 1, in the presence or absence of PS-G. Cell surface markers and phagocytic capacity were assessed by FACS analysis, and key polarizing cytokines (IL-12 p40, IL-12 p70, IL-6, IL-23, and IL-10) were quantified. The subsequent regulatory effect of pulsed MD-DCs on naïve T cells was evaluated by determining the T-cell cytokine profile.

Results

PS-G induced the maturation of MD-DCs and decreased phagocytic capacity, even if pulsed with Der p 1. After incubation with PS-G and Der p 1, MD-DCs produced higher amounts of IL-12 p70, IL-12 p40, IL-6, IL-23, and IL10 than Der p 1-pulsed DCs. Furthermore, type 1 helper T (Th1) cell cytokine (INF-γ) production was highly increased when naïve autologous T cells were co-cultured with Der p 1-pulsed MD-DCs. Naïve T cells stimulated by MD-DCs pulsed with Der p 1 failed to produce proliferation of T-cells, whereas the addition of PS-G to Der p 1 induced a significant proliferation of T-cells similar to that observed with PS-G alone.

Conclusion

The presence of PS-G in an allergen pulse promoted allergic MD-DCs to produce IL-12 p70, IL-12 p40, IL-6, IL-23, and IL-10, and exerted an effect on shifting the immune balance towards Th1 in children with allergic asthma.

Hepatitis B virus surface antigen can activate dendritic cells and modulate T helper type immune response

Hepatitis B virus surface antigen (HBsAg) is a major antigen of hepatitis B virus (HBV). Dendritic cells (DC) of HBV carriers have been reported to exhibit functional impairment. In this study, the role of HBsAg on mice bone marrow-derived dendritic cells and immune responses in vivo was studied. The immune modulatory function of HBsAg was explored by using mice bone marrow-derived dendritic cells in vitro and also by examining an ovalbumin (OVA) specific immune response in vivo. Treatment of dendritic cells with HBsAg resulted in enhanced cell surface expression of cluster of differentiation (CD) 80, CD83, CD86, and major histocompatibility complex (MHC) class II, and enhanced production of interleukin (IL)-12 p40 and IL-12 p70. Treatment of dendritic cells with HBsAg resulted in decreased T cell secretion of IL-5 by OVA stimulation. In addition, the results showed stronger OVA-specific immunoglobulin (Ig) M and weaker IgG responses in mice sera when they had been immunized with OVA and co-injected with HBsAg. It was also found that the mice exhibited significant enhancement of anti-OVA IgG2a antibody (Ab), as well as marked inhibition of IgG1 Ab production. In cellular immune responses, IL-5 production was significantly decreased and interferon (IFN)-γ increased in the group co-injected with HBsAg. On the other hand, the induction of lymphoproliferative response to OVA stimulation in spleen cells was decreased in the HBsAg co-injected group. These results demonstrate that HBsAg can affect the differentiation of T helper (Th) cells, which might provide a strategy for improving its prophylactic and therapeutic efficacy.

Genomic analysis of bacteriophage ϕAB1, a ϕKMV-like virus infecting multidrug-resistant Acinetobacter baumannii

We present the complete genomic sequence of a lytic bacteriophage ϕAB1 which can infect many clinical isolates of multidrug-resistant Acinetobacter baumannii. The recently isolated bacteriophage displays morphology resembling Podoviridae family. The ϕAB1 genome is a linear double-stranded DNA of 41,526 bp containing 46 possible open reading frames (ORFs). The majority of the predicted structural proteins were identified as part of the phage particle by mass spectrometry analysis. According to the virion morphology, overall genomic structure, and the phylogenetic tree of RNA polymerase, we propose that ϕAB1 is a new member of the ϕKMV-like phages. Additionally, we identified four ORFs encoding putative HNH endonucleases, one of which is presumed to integrate and create a genes-in-pieces DNA polymerase. Also, a potential lysis cassette was identified in the late genome. The lytic power of this bacteriophage combined with its specificity for A. baumannii makes ϕAB1 an attractive agent for therapeutic or disinfection applications.

An outbreak of human metapneumovirus infection in hospitalized psychiatric adult patients in Taiwan

Human metapneumovirus (hMPV) is a paramyxovirus that is associated with respiratory tract infection (RTI) mostly in children, but these outbreaks have rarely been reported in adults. We encountered an outbreak of this disease involving 10 adults in a psychiatric ward in eastern Taiwan. The nasopharyngeal swab specimens from 13 patients with symptoms of RTI were obtained and analyzed. The RT-PCR tests were negative to influenza virus A/B, adenovirus, RSV, parainfluenza virus, coronavirus, Nipah virus and Legionella. The antigen tests were negative to Legionella, Chlamydia, and Mycoplasma. Blood culture was negative in all except patient no. 1, who was found positive for coagulase-negative staphylococci. The hMPV was identified in 10 of 13 adults (77%), but negative for the other virus. Cough was present in all (100%), fever in 90%, and X-ray evidence of pneumonia in 7 patients. One patient died of respiratory failure. We report this outbreak in a mental hospital to alert the medical profession that this unusual infection of hMPV can occur as an outbreak in an adult setting and is an occupational hazard for healthcare personnel.

Levofloxacin versus tetracycline antibiotics for the treatment of scrub typhus

BACKGROUND

Scrub typhus is an important febrile disease in Southeast Asia and is caused by Orientia tsutsugamushi. Fluoroquinolones have proved to be effective for scrub typhus in an animal model. However, it is unclear whether they are also effective clinically.

METHODS

We retrospectively reviewed the hospital-based medical records of patients diagnosed to have scrub typhus by an indirect immunofluorescence antibody assay or PCR at a large referral hospital in Taiwan for a 6-year period (2001-2007). To determine the efficacy of levofloxacin for the treatment of scrub typhus, we divided the patients into a levofloxacin-treated group and a tetracycline antibiotics-treated group.

RESULTS

Out of 132 patients with scrub typhus, 71 initially received levofloxacin and 61 initially received tetracycline antibiotics. There was no statistically significant difference in the effective rate between the two groups (91.5% and 95.1% cured, respectively; p=0.648). The time to defervescence in the levofloxacin-treated group was longer than in the other group (49+/-41.1 and 24+/-19.6hours, respectively; p=0.001). In the patients with higher APACHE II scores, higher mortality was found in the levofloxacin-treated group (44.4% and 0%; p=0.033).

CONCLUSIONS

Levofloxacin is effective in patients with scrub typhus, but has a longer time to defervescence compared with tetracycline antibiotics. When levofloxacin is used for severe scrub typhus, higher mortality may be attributed to the longer time to defervescence.

Retrospective serological study on sequential dengue virus serotypes 1 to 4 epidemics in Tainan City, Taiwan, 1994 to 2000

BACKGROUND AND PURPOSE

We previously reported the development of a non-structural protein NS1 serotype-specific immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) for dengue serodiagnosis and seroepidemiological study. This assay can be used to differentiate the immunologic status of individuals into naive, primary, or secondary dengue virus (DENV) infection and identify the DENV serotypes of primary infection. A retrospective study was conducted to investigate the serological responses of confirmed dengue cases infected during each of the sequential DENV-1 (August 1994 to February 1995), DENV-2 (August to December 1997), DENV-3 (August 1998 to January 1999), and DENV-4 (June to December 2000) epidemics in Tainan City, Taiwan.

METHODS

218 serum samples collected 1.1 to 7.2 years postinfection were analyzed by NS1 serotype-specific IgG ELISA together with corresponding acute and/or convalescent serum samples when available. The immunological status and the infecting DENV serotypes were determined for these individuals.

RESULTS

High titers of dengue NS1 serotype-specific IgG antibody could be detected in serum samples. Differentiation of immunological status showed that 76.6% and 23.4% of cases had primary and secondary infections, respectively. A significant age-dependent increase in the rate of secondary infection was observed for those cases born before 1942. Notably, analysis of postinfection serum samples of 17 dengue hemorrhagic fever patients infected during the 1998 DENV-3 epidemic showed that 9 cases (53%) had primary infections.

CONCLUSIONS

Our data revealed that a majority of the population born after 1943 in Tainan City are naive to DENV infection and are at high risk of infection with all 4 DENV serotypes.

Immunohistochemical study of scrub typhus: a report of two cases

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi, which is transmitted by chiggers. The target cells of this rickettsia are poorly defined in humans. Immunohistochemical staining of tissue sections of patients with scrub typhus is helpful in investigating the target cells of this rickettsia in different organs. We studied two autopsy specimens by immunohistochemical staining using a specific antibody against O. tsutsugamushi. Rickettsiae were located in endothelial cells in all of the organs evaluated, namely heart, lung, brain, kidney, appendix and skin, within cardiac muscle cells and renal tubular epithelial cells, and in macrophages located in the lymph node, liver and spleen. In conclusion, O. tsutsugamushi may disseminate into multiple organs through endothelial cells and macrophages, resulting in the development of fatal complications.

Recognition of dengue virus protein using epitope-mediated molecularly imprinted film

Molecularly imprinted film was fabricated in the presence of a pentadecapeptide onto a quartz crystal microbalance (QCM) chip. This 15-mer peptide has been known as the linear epitope of the dengue virus NS1 protein. Imprinting resulted in an increased polymer affinity toward the corresponding templates but also to the virus protein. Direct detection of the dengue virus protein was achieved quantitatively. The QCM chip response to the NS1 protein was obtained using epitope-mediated imprinting demonstrating a comparable frequency shift in chips immobilized with monoclonal antibodies. The binding effect was further enhanced and confirmed using a monoclonal antibody to form a sandwich with the MIP-NS1 protein complex on the chip. No pretreatment was required.

Piezoelectric immunochip for the detection of dengue fever in viremia phase

The global prevalence of dengue fever has grown so dramatically in recent years that it is endemic in more than 100 countries and has become a major international public health concern. Moreover, since the flu-like symptoms that accompany dengue fever are atypical and varied, the detection procedures currently used to identify it are cumbersome and time-consuming, making early stage epidemiological control and effective medical treatment of this epidemic almost impossible. In this study, a QCM-based detection system was developed in which two monoclonal antibodies against dengue E and NS-1 protein, respectively, were control orientated immobilized on QCM via protein A to produce an immunochip. Various sample pretreatment procedures were evaluated to ascertain the most suitable combination, and both the simulating samples and the clinical specimen were examined by the immunochip. The results revealed that the cibacron blue 3GA gel-heat denature (CB-HD) method was the most effective sample pretreatment technique. Due to the complex composition of the serum, the immunochip could only effectively quantify dengue viral antigens in a 1/1000 untreated simulated sample. With the help of the CB-HD method, the dilution folds were found to capable of being reduced from 1000 to 100, and the detection limit lowered to 1.727 microg/ml (E protein) and 0.740 microg/ml (NS-1 protein) in the original sample. While the cocktail immunochip could not quantify both antigens separately, the higher signal level rendered it a more effective qualification tool for suspect screening. Moreover, the results of the analysis of clinical specimens also proved the ability and future potential of cocktail immunochip in discriminating dengue-positive cases from negative serum specimens in the viremia phase.

The effects of continuous epidural analgesia on Doppler velocimetry of uterine arteries during different periods of labour analgesia

BACKGROUND

The transient effects of epidural bupivacaine 0.25-0.5% on the Doppler velocimetry of umbilical and uterine arteries had been reported, but the effects of continuous lower dose epidural bupivacaine (0.05-0.1%) infusion for labour analgesia have never been reported. In this study, we evaluated the effects of continuous epidural bupivacaine 0.075% on the Doppler velocimetry of uterine arteries.

METHODS

Twenty pregnant women for labour analgesia received continuous epidural bupivacaine 0.075% infusion. We used a 4-MHz continuous-wave Doppler probe (Multigon 500A) with a 200 Hz thump filter to detect uterine blood flow velocity. We recorded the velocimetry data for uterine relaxation and contraction during five time periods: pre-epidural insertion, 1, 2, and 4 h post-epidural infusion, and after delivery of fetus.

RESULTS

Our data showed that the velocimetric indices of uterine vascular resistance were significantly increased 1, 2, and 4 h after epidural infusion when compared with the pre-epidural level; these returned to the baseline after delivery.

CONCLUSION

Continuous epidural analgesia with bupivacaine 0.075% increases the resistance of uterine artery and therefore possibly reduces the uterine blood flow.

Acute Respiratory Distress Syndrome Associated With Rabies: A Case Report

Acute respiratory distress syndrome (ARDS) is the first potentially lethal complication in rabies virus infection, although its occurrence is rare. We report on a fatal case of rabies virus infection in a 45-year-old woman from Hu-Nan Province, China. The neurologic signs of limb numbness and water phobia occurred from 61 days after the dog bite; the clinical course was progressive, with the most severe clinical manifestations being fever, encephalitis, and ARDS. The woman expired 12 days after admission to the hospital. An autopsy proved rabies encephalitis, mainly involving the medulla oblongata, the thalamus, part of the pons, the cerebellum, and the hippocampus. The lung pathologic examination revealed the organizing phase of ARDS with diffuse alveolar damage, hyaline membrane formation, type II alveolar cell hyperplasia accompanied by proliferation of fibroblasts and infiltration of mononuclear cells into the interstitial space. Immunohistochemistry stain and reverse transcription-polymerase chain reaction for rabies virus failed to demonstrate the organism in the lung tissue. Strong expression of inducible nitric oxide synthase (iNOS) was detected in the alveolar macrophages. An immunologic mechanism with iNOS expression in the absence of direct invasion of the organism may participate in the pathogenesis of ARDS associated with rabies.

Thermal aggregation of SARS-CoV membrane protein

SARS-CoV membrane protein could be detected easily using Western blotting in non-denaturing condition but not regular denaturing treatment. Boiling treatment, causing the aggregation of SARS-CoV membrane protein in the stacking gels, results in the failure to detect the membrane protein in the separating gels. Aggregated membrane proteins could not be dissociated by 1% Triton-X 100, 6 M urea, or 2% SDS. The region with amino acid residues from 51 to 170 is responsible for thermal aggregation of SARS-CoV membrane protein. Hydrophobic regions with amino acid residues from 61 to 90, from 91 to 100, from 136 to 170, are essential for this protein aggregation. Thermal aggregation of SARS-CoV membrane protein is not unique among structural proteins of coronaviruses. However, SARS-CoV membrane protein seems to be more sensitive to heat treatment, since the membrane protein of MHV-JHM, another member of the Coronaviridae, would not aggregate after the same treatment. Therefore, if SARS-CoV membrane protein needs to be analyzed using SDS-PAGE, boiling should be avoided. Thermal aggregation of SARS-CoV membrane protein may be one of the reasons for the inactivation of this virus by heat. The unusual property of SARS-CoV membrane protein aggregation induced by heat also provides a model for the study of protein aggregation.

Laboratory-based surveillance and molecular epidemiology of influenza virus in Taiwan

A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere. However, the influenza seasonality in Taiwan was not clear during the four seasons under investigation. For example, the influenza A viruses peaked during the winters of 2001, 2002, and 2003. However, some isolated peaks were also found in the summer and fall (June to November) of 2001 and 2002. An unusual peak of influenza B also occurred in the summer of 2002 (June to August). Phylogenetic analysis shows that influenza A isolates from the same year were often grouped together. However, influenza B isolates from the year 2002 clustered into different groups, and the data indicate that both B/Victoria/2/87-like and B/Yamagata/16/88-like lineages of influenza B viruses were cocirculating. Sequence comparison of epidemic strains versus vaccine strains shows that many vaccine-like Taiwanese strains were circulating at least 2 years before the vaccine strains were introduced. No clear seasonality of influenza reports in Taiwan occurred in contrast to other more continental regions.

Prenatal three-dimensional ultrasound and magnetic resonance imaging evaluation of a fetal oral tumor in preparation for the ex-utero intrapartum treatment (EXIT) procedure

Recent attempts at predelivery management of obstructed fetal airways have focused on the EXIT (ex-utero intrapartum treatment) procedure, which allows sufficient time to secure the fetal airway through preservation of uteroplacental gas exchange. We report a fetus with an exophytic oral tumor noted at 34 weeks of gestation. In this case, three-dimensional (3D) ultrasound allowed a complete and interactive evaluation of the tumor and related facial anatomy, and confirmed that access to the fetal airway was unlikely during delivery. Fetal magnetic resonance imaging (MRI) further demonstrated that the tumor originated in the nasopharynx and obstructed the upper airway. Both imaging results led to a final decision to offer an EXIT procedure for the neonate. At 36 weeks' gestation, a successful EXIT procedure was performed to reduce the risk of respiratory distress immediately after birth. This report highlights the value of 3D ultrasound and MRI as essential prerequisites for optimization of the triage process in selecting EXIT candidates.