Outcomes and Risk Factors of Bloodstream Infections Caused by Carbapenem-Resistant and Non-Carbapenem-Resistant Klebsiella pneumoniae in China.

Purpose: To compare antimicrobial resistance, virulence, clinical characteristics, and risk factors between carbapenem-resistant K. pneumoniae (CRKP) and carbapenem-susceptible K. pneumoniae (CSKP) isolates from patients with bloodstream infections (BSIs) in China. Patients and Methods: The clinical data of 103 patients with K. pneumoniae BSI from 10 hospitals were retrospectively analyzed. The minimum inhibitory concentrations of 15 antibiotics against the bacteria were determined. A Galleria mellonella infection model was used to evaluate virulence of the isolates. Kaplan-Meier curves were calculated to evaluate the 28-day and in-hospital survival rates of the isolates. The risk factors for CRKP and CSKP infection and respective mortality rate were evaluated by univariate analysis, and independent risk factors were evaluated using the multivariate logistic regression model. Results: Our results indicated that CRKP isolates were more resistant to most tested antibiotics than CSKP isolates. The G. mellonella infection model was used to demonstrate that CRKP isolates were more virulent than CSKP isolates. We found that in-hospital deaths occurred in 39.3% (22/56) of patients with CRKP BSIs and were significantly higher than those in patients with CSKP infections (19.1%, 9/47). Patients infected with CRKP isolates had poorer outcomes than those infected with the CSKP strains. For in-hospital mortality of CRKP BSIs, the independent risk factors included carbapenem-resistant Enterobacterales bacteremia and length of hospitalization after the onset of BSI. Conclusion: Our findings confirm that CRKP isolates are more drug-resistant than CSKP isolates and are associated with poorer outcomes. To prevent CRKP infection, strict infection control strategies and active surveillance should be implemented in hospitals.

Next-generation sequencing yields the complete mitochondrial genome of the Shangrila hot-spring snakes (Thermophis shangrila; Reptilia: Colubridae).

In this study, we sequenced the complete mitochondrial genome of Thermophis shangrila by using the next-generation sequencing technique. The total length of the mitogenome was 17,407 bp, which was composed of 13 protein coding genes, two rRNA genes (12s and 16s rRNA), 22 tRNA genes, and two control regions (CRI and CRII). The base composition was 32.6% for A, 23.9% for T, 30.0% for C, and 13.5% for G. We added a fragment about 150 bp in length at control region I, which Peng et al. failed to obtain using Sanger dideoxy sequencing.

Revealing the complete mitochondrial genome of Thermophis baileyi Wall, 1907 (Reptilia: Colubridae) through the next-generation sequencing.

The complete mitochondrial genome of Thermophis baileyi was sequenced using the next-generation sequencing (NGS) in the present study. The total length of the mitogenome was 17,355 bp, which was composed of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes (12s and 16s rRNA), and 2 control regions (CR I and CR II). The base composition was 32.4% for A, 23.8% for T, 30.2% for C, and 13.6% for G. Coding genes of each protein in the mtDNA had the same start and stop codons among three Thermophis species.

Molecular Characteristics of Methicillin-Resistant Staphylococcus epidermidis on the Abdominal Skin of Females before Laparotomy.

Staphylococcus epidermidis, especially methicillin-resistant strains, may be the source of surgical site infections and may be a reservoir of staphylococcal cassette chromosome mec (SCCmec) for S. aureus. The aim of this study was to investigate the prevalence of methicillin-resistant S. epidermidis (MRSE) on the abdominal skin of females before laparotomy and determine the molecular characteristics and antimicrobial susceptibility patterns of these isolates. MRSE was found in 54 of 157 isolates based on mecA gene detection, and there was no difference in icaA gene carriage rate between MRSE and methicillin-susceptible S. epidermidis (MSSE) isolates. Antimicrobial susceptibility profiles were determined by broth microdilution antimicrobial susceptibility testing according to the latest CLSI manuals. All MRSE isolates had unfavorable antimicrobial susceptibility patterns. Twenty-three MRSE strains (42.6%) were multi-drug resistant. SCCmec typing and pulsed field gel electrophoresis (PFGE) typing was performed. Thirty-nine (72.2%) had a single SCCmec type, whereas 1.9% had two types. Fourteen strains (25.9%) were non-typeable (NT). The most frequent MRSE genotype was SCCmec type IVa. High diversity with PFGE patterns was obtained for MRSE, and there were no isolates exhibiting identical pulsotype. The results confirm that methicillin-resistant strains are frequently present among S. epidermidis on the abdominal skin of females before laparotomy. Moreover, resistance profiles seem to have no association with the SCCmec types or PFGE types for most common antibiotics.

DNA barcoding and the identification of tree frogs (Amphibia: Anura: Rhacophoridae).

The DNA barcoding gene COI (cytochrome c oxidase subunit I) effectively identifies many species. Herein, we barcoded 172 individuals from 37 species belonging to nine genera in Rhacophoridae to test if the gene serves equally well to identify species of tree frogs. Phenetic neighbor joining and phylogenetic Bayesian inference were used to construct phylogenetic trees, which resolved all nine genera as monophyletic taxa except for Rhacophorus, two new matrilines for Liuixalus, and Polypedates leucomystax species complex. Intraspecific genetic distances ranged from 0.000 to 0.119 and interspecific genetic distances ranged from 0.015 to 0.334. Within Rhacophorus and Kurixalus, the intra- and interspecific genetic distances did not reveal an obvious barcode gap. Notwithstanding, we found that COI sequences unambiguously identified rhacophorid species and helped to discover likely new cryptic species via the synthesis of genealogical relationships and divergence patterns. Our results supported that COI is an effective DNA barcoding marker for Rhacophoridae.

Development of an intergeneric conjugal transfer system for xinaomycins-producing Streptomyces noursei Xinao-4.

To introduce DNA into Streptomyces noursei xinao-4, which produces xinaomycins, we explored an intergeneric conjugal transfer system. High efficiency of conjugation (8×10(-3) exconjugants per recipient) was obtained when spores of S. noursei xinao-4 were heat-shocked at 50 °C for 10 min, mixed with Escherichia coli ET12567 (pUZ8002/pSET152) in the ratio of 1:100, plated on 2CMY medium containing 40 mmol/L MgCl2, and incubated at 30 °C for 22 h. With this protocol, the plasmids pKC1139 and pSET152 were successfully transferred from E. coli ET12567 (pUZ8002) with different frequencies. Among all parameters, the ratio of donor to recipient cell number had the strongest effect on the transformation efficiency. In order to validate the above intergeneric conjugal transfer system, a glycosyltransferase gene was cloned and efficiently knocked out in S. noursei xinao-4 using pSG5-based plasmid pKC1139.

Monitoring of medical complications after acute ischemic stroke in a neurological intensive care unit.

BACKGROUND/AIMS: Post-stroke complications may influence prognosis, and may even become potentially life-threatening. The aim of this prospective study was to examine the frequency and timing of medical complications during the acute stage of critical ischemic stroke in patients treated in a neurological intensive care unit. METHODS: Seventy acute ischemic stroke patients in a critical condition with morbid changes in organs other than the brain or with severe complications were admitted to a neurological intensive care unit and followed up with assessments of 15 specified complications during the first 2 weeks on days 2, 4, 7, and 14. RESULTS: The most common complications within 2 weeks of onset were chest infection (90%), fever (64%), hypoalbuminemia (56%), arrhythmia (46%), irritable ulcer (44%), gastrointestinal dysfunction (39%), progression or recurrence of stroke (33%), and urinary tract infection (30%). The incidence of progression or recurrence of stroke and urinary tract infection peaked at day 2, and the incidence of arrhythmia, fever, chest infection, irritable ulcer, gastrointestinal dysfunction, and malnutrition peaked from 1 to 2 weeks. CONCLUSION: Progression or recurrence of stroke, fever, and chest infection are common complications in the acute stage of critical ischemic stroke.

MTAP gene is associated with ischemic stroke in Chinese Hans.

Common pathogenic mechanisms may be involved in the prevalence of ischemic stroke and coronary heart disease. Recently, genome-wide association (GWA) studies identified a chromosome region (9p21) that confers the risk of coronary heart disease. In a hospital-based case-control study conducted in Chinese Hans, we tested the hypothesis that the methylthioadenosine phosphorylase (MTAP) gene on chromosome region 9p21 is involved in the aetiology of ischemic stroke using a tagging single nucleotide polymorphism (tSNP) strategy. We observed significant association of rs10118757 in the MTAP gene with ischemic stroke. The G allele of rs10118757 was associated with an increased risk of stroke, with a per-allele OR of 1.31(95% CI, 1.04-1.65, p=0.025). The association remains after controlling for confounding factors including age, gender, body mass index, smoking, alcohol drinking, hypertension, diabetes, and hyperlipidaemia (OR=1.38, 95 CI, 1.02-1.88, p=0.039). In addition, the GA+GG genotype of rs10118757 was associated with the increased risk of an undetermined subtype of ischemic stroke (OR=2.14, 95 CI, 1.35-3.38, p=0.001). Further, we also observed the combined effects of rs10118757 with alcohol drinking and hypertension, which increased the risk of ischemic stroke. Our observations support the hypothesis that the MTAP gene may be involved in the prevalence of ischemic stroke in Chinese Hans.