Resistant pathogens, fungi, and viruses

Armed conflict and the proliferation of antimicrobial resistance: The situation in war-ravaged Afghanistan

Antimicrobial resistance (AMR) constitutes a serious impediment to the attainment of the World Health Organization's Sustainable Development Goals, which seek to ensure and promote healthy living among humans and animals. Studies have identified the vulnerability of conflict-affected populations to exposure to antimicrobial-resistant pathogens. Resource-limited countries like Afghanistan have suffered for long periods from armed conflicts, and this situation is exacerbated by the already poor or dilapidated healthcare delivery services. The country has suffered human and economic losses due to antimicrobial-resistant bacterial infections driven by the prolonged war, as well as a limited number of antimicrobials and frequent under dosage. Most reports point to the overuse of broad-spectrum antibiotics as the main reason for building up resistant strains. There is a need for more efforts toward identifying the major contributors and enlightening the public on the importance of AMR. This review aimed to provide a critical appraisal regarding the current situation of AMR in Afghanistan.

Mushroom Nutrition as Preventative Healthcare in Sub-Saharan Africa

The defining characteristics of the traditional Sub-Saharan Africa (SSA) cuisine have been the richness in indigenous foods and ingredients, herbs and spices, fermented foods and beverages, and healthy and whole ingredients used. It is crucial to safeguard the recognized benefits of mainstream traditional foods and ingredients, which gradually eroded in the last decades. Notwithstanding poverty, chronic hunger, malnutrition, and undernourishment in the region, traditional eating habits have been related to positive health outcomes and sustainability. The research prevailed dealing with food availability and access rather than the health, nutrition, and diet quality dimensions of food security based on what people consume per country and on the missing data related to nutrient composition of indigenous foods. As countries become more economically developed, they shift to “modern” occidental foods rich in saturated fats, salt, sugar, fizzy beverages, and sweeteners. As a result, there are increased incidences of previously unreported ailments due to an unbalanced diet. Protein-rich foods in dietary guidelines enhance only those of animal or plant sources, while rich protein sources such as mushrooms have been absent in these charts, even in developed countries. This article considers the valorization of traditional African foodstuffs and ingredients, enhancing the importance of establishing food-based dietary guidelines per country. The crux of this review highlights the potential of mushrooms, namely some underutilized in the SSA, which is the continent’s little exploited gold mine as one of the greatest untapped resources for feeding and providing income for Africa’s growing population, which could play a role in shielding Sub-Saharan Africans against the side effects of an unhealthy stylish diet.

Novel Peptide Conjugates of Modified Oligonucleotides for Inhibition of Bacterial RNase P

Novel alternatives to traditional antibiotics are now of great demand for the successful treatment of microbial infections. Here, we present the engineering and properties of new oligonucleotide inhibitors of RNase P, an essential bacterial enzyme. The series of 2’-O-methyl RNA (2’-OMe-RNA) and phosphoryl guanidine oligonucleotides were targeted to the substrate-binding region of M1 RNA subunit of the RNase P. Uniformly modified 2’-OMe RNA and selectively modified phosphoryl guanidine oligonucleotides possessed good stability in biological media and effectively inhibited RNase P. Their conjugates with transporting peptides were shown to penetrate bacterial cells (Escherichia coli and Acinetobacter baumannii) and inhibit bacterial growth.

Information on nosocomial infections in the mainstream media: an opinion document

This paper seeks to explore the reasons for the low impact of nosocomial infection in the mainstream media and the responsibilities of physicians and journalists in terms of this situation. To this end, a small group of 13 experts met for round-table discussions, including physicians with expertise in nosocomial infection, medical lawsuits and ethics, as well as journalists from major mainstream Spanish media outlets. The various participants were asked a series of questions prior to the meeting, which were answered in writing by one of the speakers and discussed during the meeting by the whole group, the aim being to obtain consensual conclusions for each of them. The document was subsequently reviewed, edited and forwarded to all co-authors for their agreement. The opinions expressed are the personal opinions of the participants and not necessarily those of the institutions in which they work or with which they collaborate.

Cytomegalovirus immunoglobulin G titers do not predict reactivation risk in immunocompetent hosts

Cytomegalovirus (CMV) reactivation occurs in roughly one-third of immunocompetent patients during critical illness, and is associated with worse outcomes. These outcomes have prompted consideration of early antiviral prophylaxis, but two-third of patients would receive unnecessary treatment. Tissue viral load has been associated with risk of reactivation in murine models, and recent work has suggested a relationship between immune responses to CMV and underlying viral load. We, therefore, sought to confirm the hypothesis that serum CMV-specific immunoglobulin G (IgG) correlates with tissue viral load, and might be used to predict the risk of reactivation during critical illness. We confirm that there is a good correlation between tissue viral load and serum CMV-specific IgG after laboratory infection of inbred mice. Further, we show that naturally infected outbred hosts have variable tissue viral DNA loads that do not correlate well with serum IgG. Perhaps as a consequence, CMV-specific IgG was not predictive of reactivation events in immunocompetent humans. When reactivation did occur, those with the lowest IgG levels had longer durations of reactivation, but IgG quartiles were not associated with differing peak DNAemia. Together our data suggest that CMV-specific IgG titers diverge from tissue viral loads in outbred immunocompetent hosts, and their importance for the control of reactivation events remains unclear.

Impaired polyfunctionality of CD8+ T cells in severe sepsis patients with human cytomegalovirus reactivation

Human cytomegalovirus (HCMV) establishes a lifelong chronic latent infection and often reactivates in immunocompromised patients. In addition, HCMV reactivates in patients with sepsis or other critical illnesses, particularly in patients with poor prognoses. However, the immunological characteristics of sepsis patients with HCMV reactivation have not been elucidated. In the present study, we examined T-cell responses in severe sepsis patients with and without HCMV reactivation. First, HCMV pp65-specific T-cell functions were assessed by intracellular cytokine staining (ICS) for IFN-γ, TNF-α, and MIP-1β and by CD107a staining. We analyzed the ICS data for each function individually and found no difference between the patient groups. However, the relative frequency of polyfunctional CD8⁺ T cells was significantly decreased in sepsis patients with HCMV reactivation. Next, we examined programmed cell death protein 1 (PD-1) expression. It was significantly increased in the CD8⁺ T-cell population in severe sepsis patients with HCMV reactivation, indicating CD8⁺ T-cell exhaustion. Interestingly, the frequency of PD-1⁺ cells in the CD8⁺ T-cell population was inversely correlated with the relative frequency of polyfunctional CD8⁺ T cells. Herein, we demonstrate that HCMV reactivation in severe sepsis patients is associated with PD-1 expression and impaired polyfunctionality of CD8⁺ T cells.

Aptamers against pathogenic microorganisms

An important current issue of modern molecular medicine and biotechnology is the search for new approaches to early diagnostic assays and adequate therapy of infectious diseases. One of the promising solutions to this problem might be a development of nucleic acid aptamers capable of interacting specifically with bacteria, protozoa, and viruses. Such aptamers can be used for the specific recognition of infectious agents as well as for blocking of their functions. The present review summarizes various modern SELEX techniques used in this field, and of several currently identified aptamers against viral particles and unicellular organisms, and their applications. The prospects of applying nucleic acid aptamers for the development of novel detection systems and antibacterial and antiviral drugs are discussed.

Whence Resistance?

BACKGROUND

Antimicrobial resistance results from a complex interaction between pathogenic and non-pathogenic bacteria, antimicrobial pressure, and genes, which together comprise the total body of potential resistance elements. The purpose of this study is to review and evaluate the importance of antimicrobial pressure on the development of resistance in a single surgical intensive care unit.

METHODS

We reviewed a prospectively collected dataset of all intensive care unit (ICU)-acquired infections in surgical and trauma patients over a 6-y period at a single hospital. Resistant gram-negative pathogens (rGNR) included those resistant to all aminoglycosides, quinolones, penicillins, cephalosporins, or carbapenems; resistant gram-positive infections (rGPC) included methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE). Each resistant infection was evaluated for prior or concomitant antibiotic use, previous treatment for the same (non-resistant) organism, and concurrent infection with the same organism (genus and species, although not necessarily resistant) in another ICU patient.

RESULTS

Three hundred and thirty resistant infections were identified: 237 rGNR and 93 rGPC. Infections with rGNR occurred frequently while receiving antibiotic therapy (65%), including the sensitive form of the subsequent resistant pathogen (42.2%). Infections with rGPC were also likely to occur on antimicrobial therapy (50.6%). Treatment of a different patient for an infection with the same resistant pathogen in the ICU at the time of diagnosis, implying potential patient-to-patient transmission occurred more frequently with rGNR infections (38.8%).

CONCLUSION

Antimicrobial pressure exerts a substantial effect on the development of subsequent infection. Our data demonstrate a high estimated rate of de novo emergence of resistance after treatment, which appears to be more common than patient-to-patient transmission. These data support the concept that efforts to limit antimicrobial usage will be more efficacious than enhanced isolation procedures when trying to reduce antimicrobial resistance.

Sepsis and cytomegalovirus: foes or conspirators?

Cytomegalovirus (CMV) reactivation in non-immune-suppressed critically ill patients is an area of increasing interest. CMV has long been appreciated as a pathogen in immunocompromised hosts. CMV reactivates in approximately one-third of latently infected non-immune-suppressed hosts during critical illness; however, its role as a pathogen in these patients remains unclear. CMV reactivation has been linked to bacterial sepsis and likely results from inflammation, transient immune compromise, and viral epigenetic changes. While CMV may improve immune response to some bacterial infections, other data suggest that CMV induces exaggerated responses to severe infections that may be harmful to latently infected hosts. These results also suggest that previous infection history may explain significant differences seen between human septic responses and murine models of sepsis. While critically ill human hosts clearly have worse outcomes associated with CMV reactivation, determining causality remains an area of investigation, with randomized control trials currently being performed. Here we review the current literature and highlight areas for future investigation.