1. Investigación

Wild birds have been suggested to be reservoirs of antimicrobial resistant and/or pathogenic Enterococcus faecalis (Efs) strains, but the scarcity of studies and available sequences limit our understanding of the population structure of the species in these hosts. Here, we analysed the clonal and plasmid diversity of 97 Efs isolates from wild migratory birds. We found a high diversity, with most sequence types (STs) being firstly described here, while others were found in other hosts including some predominant in poultry. We found that pheromone-responsive plasmids predominate in wild bird Efs while 35% of the isolates entirely lack plasmids. Then, to better understand the ecology of the species, the whole genome of fivestrains with known STs (ST82, ST170, ST16 and ST55) were sequenced and compared with all the Efs genomes available in public databases. Using several methods to analyse core and accessory genomes (AccNET, PLACNET, hierBAPS and PANINI), we detected differences in the accessory genome of some lineages (e.g. ST82) demonstrating specific associations with birds. Conversely, the genomes of other Efs lineages exhibited divergence in core and accessory genomes, reflecting different adaptive trajectories in various hosts. This pangenome divergence, horizontal gene transfer events and occasional epidemic peaks could explain the population structure of the species.

More than a century ago, independent groups raised the possibility of using bacteria to selectively infect tumours. Such treatment induces an immune reaction that can cause tumour rejection and protect the patient against further recurrences. One of the first holistic approximations to use bacteria in cancer treatment was performed by William Coley, considered the father of immune-therapy, at the end of XIX century. Since then, many groups have used different bacteria to test their antitumour activity in animal models and patients. The basis for this reactivity implies that innate immune responses activated upon bacteria recognition, also react against the tumour. Different publications have addressed several aspects of oncolytic bacteria. In the present review, we will focus on revisiting the historical aspects using bacteria as oncolytic agents and how they led to the current clinical trials. In addition, we address the molecules present in oncolytic bacteria that induce specific toxic effects against the tumors as well as the activation of host immune responses in order to trigger antitumour immunity. Finally, we discuss future perspectives that could be considered in the different fields implicated in the implementation of this kind of therapy in order to improve the current use of bacteria as oncolytic agents.

The 2022 annual meeting of the HTLV & HIV‐2 Spanish Network was held in Madrid on December 14. We summarize here the main information presented and discussed at the workshop and review time trends for human retroviral infections in Spain. As transmissible agents, infections by human retroviruses are of obligatory declaration. Until the end of 2022, the Spanish national registry had recorded 451 cases of HTLV‐1, 821 of HTLV‐2, and 416 of HIV‐2. For HIV‐1, estimates are of 150 000 people currently living with HIV‐1 and 60 000 cumulative deaths due to AIDS. During year 2022, new diagnoses in Spain were of 22 for HTLV‐1, 6 for HTLV‐2, and 7 for HIV‐2. The last updated figures for HIV‐1 are from 2021 and counted 2786 new diagnoses. The slowdown in yearly infections for HIV‐1 in Spain points out that new strategies are needed to achieve the United Nations 95‐95‐95 targets by 2025. For the remaining neglected human retroviral infections, their control might be pushed throughout four interventions: (1) expanding testing; (2) improving education and interventions aimed to reduce risk behaviors; (3) facilitating access to antiretrovirals as treatment and prevention, including further development of long‐acting formulations; and (4) increasing vaccine research efforts. Spain is a 47 million population country in South Europe with strong migration flows from HTLV‐1 endemic regions in Latin America and Sub‐Saharan Africa. At this time universal HTLV screening has been implemented only in the transplantation setting, following the report of 5 cases of HTLV‐associated myelopathy shortly after transplantation of organs from HTLV‐1 positive donors. There are four target populations for expanding testing and unveiling asymptomatic carriers responsible for silent HTLV‐1 transmissions: (1) migrants; (2) individuals with sexually transmitted infections; (3) pregnant women; and (4) blood donors.