Impact of multiplex polymerase chain reaction syndromic panel on antibiotic use among hospitalized children with respiratory tract illness during COVID-19 pandemic

BACKGROUND/PURPOSE

Precise detection of respiratory pathogens by molecular method potentially may shorten the time to diagnose and reduce unnecessary antibiotic use.

METHODS

Medical records of hospitalized children from January 2020 to June 2021 with acute respiratory illness who received a FilmArray RP for respiratory pathogens were reviewed and compared with data from diagnosis-matched patients without receiving the test.

RESULTS

In total, 283 patients and 150 diagnosis-matched controls were included. Single pathogen was detected in 84.3% (193/229) of the patients. The most common pathogen was human rhinovirus/enterovirus (31.6%, 84/266), followed by respiratory syncytial virus (18.8%, 50/266) and adenovirus (15%, 40/266). Although antimicrobial days of therapy (DOT) was significantly longer in FilmArray group than the control [7.1 ± 4.9 days vs 5.7 ± 2.7 days, P = 0.002], the former showed a higher intensive care unit (ICU) admission rate (3.9% vs 0%; P = 0.010). All ICU admissions were in FilmArray RP-positive group. There was no difference in antimicrobial DOT between FilmArray RP-positive and the negative groups, in all admissions, even after excluding ICU admissions. Antimicrobial DOT was shorter in the positive than negative group in patients with lower respiratory tract infections without admission to ICU [median (IQR): 6 (4-9) days vs 9 (4-12) days, P = 0.047].

CONCLUSIONS

Shorter antimicrobial DOTs were identified in children with lower respiratory tract infection admitted to general pediatric ward and with an identifiable respiratory pathogen, indicating a role of the multiplex PCR in reducing antimicrobial use for children with respiratory tract infection.

Carbapenem-resistant Enterobacteriaceae infection in children less than one year old in an Asian medical center

BACKGROUND

The emergence of carbapenem-resistant Enterobacteriaceae (CRE) is a threat to public health worldwide. This study aimed to determine the risk factors and outcomes for CRE colonization and infection in infants.

METHODS

Children aged <1 year hospitalized with CRE pathogens isolated from January 2016 to June 2019 were retrospectively analyzed. Demographic and clinical data were examined.

RESULTS

A total of 48 infections were identified in 70 infants aged <1 year, and 66.7% (32/48) of these infants were born preterm. The infection rate in infants aged <1 month was higher than that of others (P = 0.005). The most commonly isolated CRE was Klebsiella pneumoniae (60.4%, 29/48), followed by Enterobacter cloacae complex (18.8%, 9/48). Sputum (37.5%, 18/48), blood (27.1%, 13/48), and urine (25.0%, 12/48) were the most common clinical samples. Urinary tract infection was common in infants aged 6-12 months. CRE infection was associated with mechanical ventilation (P = 0.037), central venous catheter (CVC) insertion (P = 0.034), and congenital heart disease (P = 0.027). The hospital stay of patients with CRE infection was longer (median, 75 days; SD, 66.4 days), and their all-cause mortality (6.4%) was higher than those with colonization.

CONCLUSIONS

CRE infection was common in infants aged <1 month, and patients usually had longer hospitalization. Carbapenemase production was not common. Mechanical ventilation, CVC insertion, and congenital heart disease were associated with a higher risk of CRE acquisition in infants aged <1 year.

Risk factors and outcomes of Clostridium difficile infection in hospitalized patients

BACKGROUND

The aim of this study was to identify risk factors for Clostridium difficile infection (CDI) and its attributable mortality and to propose methods to prevent CDI and improve patients' outcomes.

METHODS

CDI was defined as diarrheal patients with stool samples that were positive for C. difficile toxin. Clinical presentations of all patients with CDI and two times as many age- and sex-matched culture-negative controls at the Chang Gung Memorial Hospital in 2014 were identified and compared by multivariate, nonparametric, and Kaplan-Meier survival analysis.

RESULTS

There were no significant differences in ages, sex, or Charlson comorbidity indexes between the CDI group (n = 42) and the control group (n = 86). The multivariate analysis indicated that underlying peptic ulcer disease and previous use of gastric acid inhibitors or third-generation cephalosporins for at least 3 days were significantly more common in patients with CDI than in the controls. Charlson scores were associated with mortality due to CDI. Recommended treatment using oral vancomycin to treat patients with Charlson score ≥ 5 and oral metronidazole or vancomycin to treat those with moderate underlying disease (Charlson score ≥ 2 and ≤ 5) significantly increased survival in these patients (p = 0.001).

CONCLUSIONS

Oral vancomycin given to patients with high Charlson scores and oral metronidazole or vancomycin to patients with moderate Charlson scores decreased mortality due to CDI. Restricting the use of third-generation cephalosporins and gastric acid inhibitors is recommended to prevent CDI in hospitalized patients.

Venovenous extracorporeal life support for posttraumatic respiratory distress syndrome in adults: the risk of major hemorrhages

Background

The aim of this retrospective study is to investigate the therapeutic benefits and the bleeding risks of venovenous extracorporeal life support (VV-ECLS) when used for adult posttraumatic respiratory distress syndrome (posttraumatic ARDS).

Materials and methods

Twenty adult trauma patients (median age: 38 years, median injury severity score: 35) treated with VV-ECLS in a level I trauma center between January 2004 and June 2013 were enrolled in this study. The indication of VV-ECLS for posttraumatic ARDS was refractory hypoxemia (P_aO₂/F_iO₂ ratio ≤ 70 mmHg) under advanced mechanical ventilation. To minimize potential complications, a protocol-guided VV-ECLS was adopted.

Results

Sixteen patients were weaned off VV-ECLS, and of these patients fourteen survived. Medians of the trauma-to-ECLS time, the pre-ECLS mechanical ventilation, and the ECLS duration in all patients were 64, 45, and 144 hours respectively. The median P_aO₂/F_iO₂ ratio was improved significantly soon after VV-ECLS, from 56 to 106 mmHg (p < 0.001). However, seven major hemorrhages occurred during VV-ECLS, of which three were lethal. The multivariate analysis revealed that the occurrence of major hemorrhages during VV-ECLS was independently related to the trauma-to-ECLS time < 24 hours (OR: 20; p = 0.02; 95% CI: 2–239; c-index: 0.81).

Conclusions

Despite an effective respiratory support, VV-ECLS should be cautiously administered to patients who develop advanced ARDS soon after major trauma.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-014-0056-0) contains supplementary material, which is available to authorized users.

Identification of the first nucleated phase in submonolayer Ti deposited on Si(111)-7×7 by atomic resolution techniques

Ti5Si4 has been identified to be the first nucleated phase in submonolayer Ti deposited on the Si(111)-7 x 7 surface by ultrahigh vacuum scanning tunneling microscopy in conjunction with atomic-resolution transmission electron microscopy. The direct observation of the formation of clusters surrounded by the heavily damaged silicon lattice strongly suggested that Si is the dominant diffusing species in forming the silicide.

Characterization of a 5'-flanking region supporting the transcription of mouse thymosin beta-4 in mouse NIH3T3 cells

Expression of the gene coding for thymosin beta-4 (Tbeta-4), the major G-actin sequestering peptide in the cell, is regulated mainly at the level of transcription. In this study, we examined the nucleotide sequence of the 5'-flanking region (from -2202 to -881) of the mouse Tbeta-4 gene, and demonstrated that the DNA fragment from -278 to +410 of this gene was capable of directing the expression of a chloramphenicol acetyltransferase reporter gene in NIH3T3 cells. However, expression of the reporter gene in cells cannot be induced by interferon-alpha treatment even though a rapid activation of endogenous Tbeta-4 gene by this cytokine was observed. These results suggest that the projected interferon-stimulated response element (ISRE) might reside in other parts of the mouse Tbeta-4 gene.

Role of intestinal P-glycoprotein (mdr1) in interpatient variation in the oral bioavailability of cyclosporine

Interpatient differences in the oral clearance of cyclosporine (INN, ciclosporin) have been partially attributed to variation in the activity of a single liver enzyme termed CYP3A4. Recently it has been shown that small bowel also contains CYP3A4, as well as P-glycoprotein, a protein able to transport cyclosporine. To assess the importance of these intestinal proteins, the oral pharmacokinetics of cyclosporine were measured in 25 kidney transplant recipients who each had their liver CYP3A4 activity quantitated by the intravenous [14C-N-methyl]-erythromycin breath test and who underwent small bowel biopsy for measurement of CYP3A4 and P-glycoprotein. Forward multiple regression revealed that 56% (i.e., r2 = 0.56) and 17% of the variability in apparent oral clearance [log (dose/area under the curve)] were accounted for by variation in liver CYP3A4 activity (p < 0.0001) and intestinal P-glycoprotein concentration (p = 0.0059), respectively. For peak blood concentration, liver CYP3A4 activity accounted for 32% (p = 0.0002) and P-glycoprotein accounted for an additional 30% (p = 0.0024) of the variability. Intestinal levels of CYP3A4, which varied tenfold, did not appear to influence any cyclosporine pharmacokinetic parameter examined. We conclude that intestinal P-glycoprotein plays a significant role in the first-pass elimination of cyclosporine, presumably by being a rate-limiting step in absorption. Drug interactions with cyclosporine previously ascribed to intestinal CYP3A4 may instead be mediated by interactions with intestinal P-glycoprotein.

Sequencing analysis of hepatitis C virus mixed genotype in a hemodialysis patients

It has become clear that the genotypes of HCV vary with respect to pathogenicity, infectivity, response to antiviral therapy and geographic clustering. The prevalence of genotype distribution of HCV infection in Taiwan was investigated by typing with type-specific DNA primers in HCV core region. Using a design by Okamoto et al., it was found that in 280 serum samples examined, 3.3% (4/122) of the virus detected were mixed type. The implication of mixed type infection remains to be clarified: whether it is a single infection with a new variant, or infection with two HCV virions at different times or confusion with type-specific DNA primers themselves. The nucleotide sequences of the recombinant plasmid DNAs and the PCR products recovered from gel electrophoresis were analyzed by autosequencer. Gene sequences of HCV cDNAs of the two blood donors were used as control. To double check the results, we have also analyzed the DNA sequences of the cloned plasmids in the NS5 region with the primer system designed by Chayama et al. Results indicated that the hemodialysis patient was doubly infected with HCV, rather than by a HCV variant.

Detection and identification of toxigenic Vibrio cholerae O1 strains by a simplified polymerase chain reaction method

The polymerase chain reaction (PCR) with three oligonucleotide primers was used to amplify both 184 bp and 425 bp DNA fragments of cholera toxin A subunit gene (ctxA) for detection and identification of toxigenic V. cholerae O1 strains in one step. For enhancing the sensitivity, we have used the chemiluminescent detection system for Southern hybridization. A total of 92 Vibrio strains were tested by both PCR and enzyme-linked immunosorbent assay (ELISA). Three E. coli (ETEC) strains, one toxigenic V. mimicus, and one toxigenic V. cholerae non-O1 were also tested for cross reactivities. Our results indicated that the correlation between the immunological ELISA method and the molecular biological PCR method were very well. The lowest detectable amount of the purified serotype Inaba chromosomal DNA by PCR is 2 pg and 0.4 pg by chemiluminescent detection system. In this work we report a PCR assay with a combination of three primers to detect and identify the ctxA of V. cholerae O1 in one step. The simplified and accurate method is useful for toxigenic V. cholerae O1 detection and identification.