Isolation and genomic characterization of a novel Autographiviridae bacteriophage IME184 with lytic activity against Klebsiella pneumoniae

Klebsiella pneumoniae, a multidrug resistant bacterium that causes nosocomial infections including septicemia, pneumonia etc. Bacteriophages are potential antimicrobial agents for the treatment of antibiotic resistant bacteria. In this study, a novel bacteriophage IME184, was isolated from hospital sewage against clinical multi-drug resistant Klebsiella pneumoniae. Transmission electron microscopy and genomic characterization exhibited this phage belongs to the Molineuxvirinae genus, Autographiviridae family. Phage IME184 possessed a double-stranded DNA genome composed of 44,598 bp with a GC content of 50.3%. The phage genome encodes 57 open reading frames, out of 26 are hypothetical proteins while 31 had assigned putative functions. No tRNA, virulence related or antibiotic resistance genes were found in phage genome. Comparative genomic analysis showed that phage IME184 has 94% similarity with genomic sequence of Klebsiella phage K1-ULIP33 (MK380014.1). Multiplicity of infection, one step growth curve and host range of phage were also measured. According to findings, Phage IME184 is a promising biological agent that infects Klebsiella pneumoniae and can be used in future phage therapies.

Association of Mannose-Binding Lectin 2 Gene Polymorphism with Tuberculosis Based on Mycobacterium tuberculosis Lineages

Purpose

Polymorphisms in MBL2 may contribute to the susceptibility to tuberculosis. The aim of the present study was to determine the associations of the polymorphisms of five loci (rs1800450, rs1800451, rs7096206, rs7095891, and rs11003125) in the MBL2 gene with susceptibility to tuberculosis and specific lineages of Mycobacterium tuberculosis causing tuberculosis in the Uyghur population of Xinjiang, China.

Methods

From January 2019 to January 2020, we enrolled 170 Uyghur tuberculosis patients as the case group and 147 Uyghur staff with no clinical symptoms as the control group from four designated tuberculosis hospitals in southern Xinjiang, China. The polymorphisms of five loci in MBL2 of human were detected by sequencing. Whole-genome sequencing was applied in 68 M. tuberculosis isolates from the case group and the data were used to perform genealogy analysis.

Results

The distributions of allele and genotype frequencies of five loci in MBL2 varied little between the case and control groups and varied little among the groups, including those infected with different lineages of M. tuberculosis and the control (except those of rs11003125), the P values were all >0.05. The distribution of alleles of rs11003125 was statistically different between patients infected with lineages 3 and 4 M. tuberculosis (χ²=7.037, P=0.008). The C allele and CC genotype of rs11003125 were found to be protective factors against lineage 4 infection when compared to lineage 3 (ORs were 0.190 and 0.158, respectively; 95% confidence intervals were 0.053~0.690 and 0.025~0.999, respectively).

Conclusion

Our results suggested that human’s susceptibility to tuberculosis is affected both by the host genetic polymorphisms and the lineage of the M. tuberculosis that people were exposed to. However, due to the limitation of the sample size in the present study, larger sample size and more rigorous design should be guaranteed in future studies.

Molecular Characterization and TRAP Analysis of Gene in Dendranthema morifolium

The molecular maker system - TRAP was applied to develop a novel and more accurate method to identify the variety and establish the evolutionary relationship of different categories of Dendranthema morifolium. A software - GENESIS 2.4 was used to conduct the cluster analysis and genetic dendrogram establishment. The results showed that 202 different fragments were amplified with 6 pair primers using the TRAP marker system. The polymorphic fragments number is 45, which takes up to 22.3%. The cluster analysis showed that 4 materials used in this study can be classified into 2 main groups and 3 subgroups. The genetic identity is 0.0767 and the average genetic distance is 0.9236 among the four materials. A new tool using the TRAP marker system is more accurate and can be used to identify different categories of Dendranthema morifolium at molecular level.

Bone marrow Penicillium marneffei infection in acquired immunodeficiency syndrome patients: report of 35 cases

Penicilliosis is a tropical disease occurring mostly in Southeast Asia. The incidence of Penicillium marneffei infection in acquired immunodeficiency syndrome (AIDS) patients is increasing due to the infection of the HIV in the population in recent years. In this report, the bone marrow smears of 331 AIDS patients have been examined for the evidence of P. marneffei infection, and 35 (10.6%) of whom were found positive, showing the existing of pathogen in the bone marrow smears. This result indicates that bone marrow P. marneffei infection is a serious complication in HIV infected patients and the inspection of bone marrow should be considered as a routine procedure during treatment.

A randomized open study to assess the efficacy and tolerability of dihydroartemisinin-piperaquine for the treatment of uncomplicated falciparum malaria in Cambodia

OBJECTIVES

To compare the efficacy and tolerability of dihydroartemisinin-piperaquine (DHA-PQP) with that of a 3-day regimen of mefloquine and artesunate (MAS3) for the treatment of uncomplicated falciparum malaria in Cambodia.

METHOD

Randomized open-label non-inferiority study over 64 days.

RESULTS

Four hundred and sixty-four patients were included in the study. The polymerase chain reaction genotyping-adjusted cure rates on day 63 were 97.5% (95% confidence interval, CI, 93.8-99.3) for DHA-PQP and 97.5% (95% CI, 93.8-99.3) for MAS3, P = 1. There were no serious adverse events, but significantly more episodes of vomiting (P = 0.03), dizziness (P = 0.002), palpitations (P = 0.04), and sleep disorders (P = 0.03) reported in the MAS3 treatment group, consistent with the side-effect profile of mefloquine.

CONCLUSIONS

DHA-PQP was as efficacious as MAS3, but much better tolerated, making it more appropriate for use in a routine programme setting. This highly efficacious, safe and more affordable fixed-dose combination could become the treatment of choice for Plasmodium falciparum malaria in Cambodia.

Induction of human immunodeficiency virus type 1 expression in monocytic cells by Cryptococcus neoformans and Candida albicans

Because candidiasis and cryptococcosis are common in human immunodeficiency virus (HIV)-infected persons, the effect of Cryptococcus neoformans and Candida albicans on HIV expression in monocytic cells was examined. Stimulation of the latently HIV-infected myelomonocytic cell line OM-10.1 with C. neoformans and C. albicans in the presence of pooled human serum caused a ratio-dependent increase in HIV production. Induction of HIV by C. neoformans was enhanced by anti-capsular antibody, while induction by both organisms was inhibited by anti-TNF-alpha antibody. In THP-1 cells transfected with HIV plasmid constructs, both organisms induced transcription from the HIV long terminal repeat that was dependent on intact NF-kappaB binding sequences. Thus, C. neoformans and C. albicans enhance HIV expression in monocytic cells through a TNF-alpha- and NF-kappaB-dependent mechanism. In HIV-infected patients, such enhancement may further impair host immunity and could accelerate the course of HIV disease.