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Enterococcus faecium has been classified as a "high priority" pathogen by the World Health Organization. Enterococcus faecium has rapidly evolved as a global nosocomial pathogen with adaptation to the nosocomial environment and the accumulation of resistance to multiple antibiotics. Phage therapy is considered a promising strategy against difficult-to-treat infections and antimicrobial resistance. In this study, we isolated and characterized a novel virulent bacteriophage, vB_Efm_LG62, that specifically infects multidrug-resistant E. faecium. Morphological observations suggested that the phage has siphovirus morphology, with an optimal multiplicity of infection of 0.001. One-step growth tests revealed that its latent growth was at 20 min, with a burst size of 101 PFU/cell. Phage vB_Efm_LG62 was verified to have a double-stranded genome of 42,236 bp (35.21% GC content), containing 66 predicted coding sequences as determined by whole genomic sequencing. No genes were predicted to have functions associated with virulence factors or antibiotic resistance, indicating that the phage vB_Efm_LG62 has good therapeutic potential. Our isolation and characterization of this highly efficient phage aids in expanding our knowledge of E. faecium-targeting phages, and provides additional options for phage cocktail therapy. [ABSTRACT FROM AUTHOR]

Improving the capacity of detecting positive severe acute respiratory syndrome coronavirus 2 is critical for identifying the infection of coronavirus disease 2019 (COVID-19) precisely and thereby curbing the pandemic. Cross-disciplinary approaches may improve the efficiency of COVID-19 diagnosis by compensating to some extent the limitations encountered by traditional test methods during the COVID-19 pandemic. Combining computed tomography (CT), serum-specific antibody detection, and nanopore sequencing with nucleic acid testing for individual testing may improve the accuracy of identifying COVID-19 patients. At community or even regional/national levels, the combination of pooled screening and spatial epidemiological strategies may enable the detection of early transmission of epidemics in a cost-effective way, which is also less affected by restricted access to diagnostic tests and kit supplies. This would significantly advance our capacity of curbing epidemics as soon as possible, and better prepare us for entering a new era of high-impact and high-frequency epidemics. [ABSTRACT FROM AUTHOR]

Hepatitis B virus infection is highly endemic in China, especially in rural areas such as Dianjiang County with poor-quality health care and little local HBV information. Therefore, for the first time, the present study was carried out to investigate the molecular epidemiology, phylogeny and population dynamics of HBV based on 146 HBV-infected patients. A 435-bp portion of the HBV S region was sequenced, and the phylogeny was reconstructed, indicating that three genotypes, B, C and D of HBV were distributed in Dianjiang County. The predominant genotype is B (67.12 %), followed by C (32.19 %) and D (0.68 %). Patient demographic information and clinical outcomes were examined by genotypes, and no significant association was found. Population dynamics analysis suggested that both genotype B and C have experienced a tenfold expansion during the last five years for reasons that are unclear. Thus, a thorough molecular epidemiology investigation is strongly recommended in the future. [ABSTRACT FROM AUTHOR]

AIDS is becoming one of leading cause of death among infectious diseases in China. There has been rapidly increasing epidemic of HIV/AIDS in Chengdu since 2003. In order to investigate HIV-1 subtype distribution, drug resistance-associated mutations as well as drug resistance prevalence among treatment naïve HIV-infected individuals in Chengdu of China, 244 HIV confirmed-reactive serum samples were collected from 2007 to 2010, including 165 obtained from blood centers and 79 obtained from hospitals. HIV-1 pol including whole protease, and partial reverse transcriptase genes was amplified, sequenced, and analyzed for subtype determination and drug resistance profile description. A total of 159 amplified sequences which were acquired from 98 sample obtained at blood centers and 61 samples obtained at hospitals had the following genotype distribution: G (0.6 %), F1 (0.6 %), A1 (0.6 %), B (1.9 %), circulating recombinant form (CRF) 01_AE (42.8 %), CRF07_BC (49.1 %), and CRF08_BC (4.4 %). There were 12.2 and 24.6 % samples obtained from blood centers and hospitals, respectively, that harbored drug resistance-associated mutations, and the prevalence of drug resistance among all cases was 1.3 %. This was the first report of HIV molecular surveillance among treatment naïve HIV-infected individuals in Chengdu. Our findings were believed to be helpful on contribution to comprehensive HIV control program in China. [ABSTRACT FROM AUTHOR]

Although the genetic variability of hepatitis B virus (HBV) in HBV-infected patients has been extensively studied, reports on genotypes, subtypes and mutations in the S region of HBV strains from Chinese blood donors are limited. In this study, 245 blood samples from HBsAg-positive blood donors were collected from five geographically diverse blood centers in China. The S region of HBV was amplified, and the HBV genotype and subtype were determined. The amino acid sequences of the S region were aligned, and mutations related to the failure of immunization and HBsAg detection were determined. Of the 245 samples, 228 (93 %) were genotyped successfully. We found that genotypes B, C, D and A accounted for 58.8 %, 21.9 %, 6.6 % and 3.95 % of the isolates, respectively. The distribution of HBV antigen subtypes was as follows: adw (67.6 %), adr (23.3 %) and ayw (8.7 %). Mutations were present in 39 (17.1 %) of 228 samples in the major hydrophilic region (MHR) of the S region. This study demonstrated that HBV genotype/subtype B/adw was the most frequent strain circulating in HBV-infected Chinese blood donors, followed by C/adr. The occurrence of MHR mutants in HBV-infected blood donors and the potential failure to detect some of them in collected units poses a threat to transfusion safety. [ABSTRACT FROM AUTHOR]