IFI44 is an immune evasion biomarker for SARS-CoV-2 and Staphylococcus aureus infection in patients with RA.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic of severe coronavirus disease 2019 (COVID-19). Staphylococcus aureus is one of the most common pathogenic bacteria in humans, rheumatoid arthritis (RA) is among the most prevalent autoimmune conditions. RA is a significant risk factor for SARS-CoV-2 and S. aureus infections, although the mechanism of RA and SARS-CoV-2 infection in conjunction with S. aureus infection has not been elucidated. The purpose of this study is to investigate the biomarkers and disease targets between RA and SARS-CoV-2 and S. aureus infections using bioinformatics analysis, to search for the molecular mechanisms of SARS-CoV-2 and S. aureus immune escape and potential drug targets in the RA population, and to provide new directions for further analysis and targeted development of clinical treatments. Methods: The RA dataset (GSE93272) and the S. aureus bacteremia (SAB) dataset (GSE33341) were used to obtain differentially expressed gene sets, respectively, and the common differentially expressed genes (DEGs) were determined through the intersection. Functional enrichment analysis utilizing GO, KEGG, and ClueGO methods. The PPI network was created utilizing the STRING database, and the top 10 hub genes were identified and further examined for functional enrichment using Metascape and GeneMANIA. The top 10 hub genes were intersected with the SARS-CoV-2 gene pool to identify five hub genes shared by RA, COVID-19, and SAB, and functional enrichment analysis was conducted using Metascape and GeneMANIA. Using the NetworkAnalyst platform, TF-hub gene and miRNA-hub gene networks were built for these five hub genes. The hub gene was verified utilizing GSE17755, GSE55235, and GSE13670, and its effectiveness was assessed utilizing ROC curves. CIBERSORT was applied to examine immune cell infiltration and the link between the hub gene and immune cells. Results: A total of 199 DEGs were extracted from the GSE93272 and GSE33341 datasets. KEGG analysis of enrichment pathways were NLR signaling pathway, cell membrane DNA sensing pathway, oxidative phosphorylation, and viral infection. Positive/negative regulation of the immune system, regulation of the interferon-I (IFN-I; IFN-α/ß) pathway, and associated pathways of the immunological response to viruses were enriched in GO and ClueGO analyses. PPI network and Cytoscape platform identified the top 10 hub genes: RSAD2, IFIT3, GBP1, RTP4, IFI44, OAS1, IFI44L, ISG15, HERC5, and IFIT5. The pathways are mainly enriched in response to viral and bacterial infection, IFN signaling, and 1,25-dihydroxy vitamin D3. IFI44, OAS1, IFI44L, ISG15, and HERC5 are the five hub genes shared by RA, COVID-19, and SAB. The pathways are primarily enriched for response to viral and bacterial infections. The TF-hub gene network and miRNA-hub gene network identified YY1 as a key TF and hsa-mir-1-3p and hsa-mir-146a-5p as two important miRNAs related to IFI44. IFI44 was identified as a hub gene by validating GSE17755, GSE55235, and GSE13670. Immune cell infiltration analysis showed a strong positive correlation between activated dendritic cells and IFI44 expression. Conclusions: IFI144 was discovered as a shared biomarker and disease target for RA, COVID-19, and SAB by this study. IFI44 negatively regulates the IFN signaling pathway to promote viral replication and bacterial proliferation and is an important molecular target for SARS-CoV-2 and S. aureus immune escape in RA. Dendritic cells play an important role in this process. 1,25-Dihydroxy vitamin D3 may be an important therapeutic agent in treating RA with SARS-CoV-2 and S. aureus infections.

[Impact of Staphylococcus aureus bacteremia in COVID-19 patients]. / Impacto de la bacteriemia por Staphylococcus aureus en pacientes con COVID-19.

OBJECTIVE: The disease caused by SARS-CoV-2 (COVID-19) has been a challenge for healthcare professionals since its appearance. Staphylococcus aureus has been described as one of the main pathogens causing bacterial infections in viral pandemics. However, co- infection with S. aureus causing bacteremia in patients with COVID-19 has yet to be well studied. METHODS: We performed a e study of S. aureus bacteremia (SAB) at Hospital Miguel Servet (Zaragoza) from March 2020 to February 2021. The clinical characteristics, mortality and risk factors of adults hospitalized patients with BSA associated COVID-19 compared to patients without COVID-19. RESULTS: A total of 95 patients with SAB were identified. 27.3% were positive for SARS-CoV-2. SAB represented 9.9% of bacteremia, being the second agent in frequency after E. coli. Nosocomial bacteremia was more frequent in the group of COVID-19 patients. The most frequent source of BSA in these patients was the respiratory source (26.9% vs 0%; P<0.001) followed by the skin (15.5% vs 15.9%; P=1). The development of sepsis was more frequent in COVID-19 patients (61,5% vs 7,8%; P=0,336) and among them, who received dexamethasone at doses > 6 mg/day (62.5% vs. 37.5%, P<0.05). CONCLUSIONS: Our data suggest that BSA has a negative impact on the evolution of patients with COVID-19. However, further and preferably prospective studies are required to obtain solid data on the impact of BSA on coronavirus patients.

Impact of respiratory bacterial infections on mortality in Japanese patients with COVID-19: a retrospective cohort study.

BACKGROUND: Although cases of respiratory bacterial infections associated with coronavirus disease 2019 (COVID-19) have often been reported, their impact on the clinical course remains unclear. Herein, we evaluated and analyzed the complication rates of bacterial infections, causative organisms, patient backgrounds, and clinical outcome in Japanese patients with COVID-19. METHODS: We performed a retrospective cohort study that included inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021) and obtained demographic, epidemiological, and microbiological results and the clinical course and analyzed the cases of COVID-19 complicated by respiratory bacterial infections. RESULTS: Of the 1,863 patients with COVID-19 included in the analysis, 140 (7.5%) had respiratory bacterial infections. Community-acquired co-infection at COVID-19 diagnosis was uncommon (55/1,863, 3.0%) and was mainly caused by Staphylococcus aureus, Klebsiella pneumoniae and Streptococcus pneumoniae. Hospital-acquired bacterial secondary infections, mostly caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were diagnosed in 86 patients (4.6%). Severity-associated comorbidities were frequently observed in hospital-acquired secondary infection cases, including hypertension, diabetes, and chronic kidney disease. The study results suggest that the neutrophil-lymphocyte ratio (> 5.28) may be useful in diagnosing complications of respiratory bacterial infections. COVID-19 patients with community-acquired or hospital-acquired secondary infections had significantly increased mortality. CONCLUSIONS: Respiratory bacterial co-infections and secondary infections are uncommon in patients with COVID-19 but may worsen outcomes. Assessment of bacterial complications is important in hospitalized patients with COVID-19, and the study findings are meaningful for the appropriate use of antimicrobial agents and management strategies.

Infectious Diseases: What You May Have Missed in 2022.

In 2022, COVID-19 remained the infectious disease at the top of most internal medicine physicians' minds. However, it was not the only infectious disease that was the topic of clinically relevant research that year. This article highlights some important infectious disease evidence unrelated to COVID-19 that was published in 2022. The literature was screened for sound new evidence relevant to internal medicine specialists and subspecialists whose focus of practice is not infectious diseases. The publications highlighted relate to various organisms in different patient populations. One article provides insight into the role of Helicobacter pylori eradication in the treatment of functional dyspepsia. The descriptive epidemiology of bacterial (Staphylococcus aureus) and viral (mpox) infections are the focus of 2 other articles. Several articles address the management of resistant and difficult-to-treat infections: multidrug-resistant gram-negative infections, resistant HIV-1, rifampin-resistant tuberculosis, cryptococcal meningitis, and invasive fungal infection in the setting of neutropenia. Another article provides data on effective HIV preexposure prophylaxis in women, an understudied population. Finally, given the urgent need to reduce inappropriate use of antibiotics, an article on antibiotic stewardship for hospitalized patients with presumed sepsis in a non-intensive care unit setting is also included.

Effects of 5α-dihydrotestosterone on the modulation of monocyte/macrophage response to Staphylococcus aureus: an in vitro study.

BACKGROUND: Staphylococcus aureus (S. aureus) is a pathogen responsible for a wide range of clinical manifestations and potentially fatal conditions. There is a paucity of information on the influence of androgens in the immune response to S. aureus infection. In this study, we evaluated the influence of the hormone 5α-dihydrotestosterone (DHT) on mouse peritoneal macrophages (MPMs) and human peripheral blood monocytes (HPBMs) induced by S. aureus. METHODS: An in vitro model of MPMs from BALB/c sham males, orchiectomised (OQX) males, and females was used. Cells were inoculated with 10 µL of S. aureus, phage-type 80 or sterile saline (control) for 6 h. The MPMs of OQX males and females were pre-treated with 100 µL of 10-2 M DHT for 24 h before inoculation with S. aureus. The concentration of the cytokines TNF-α, IL-1α, IL-6, IL-8, and IL-10; total nitrites (NO-2); and hydrogen peroxide (H2O2) were measured in the supernatant of MPM cultures. In addition, the toll-like receptor 2 (TLR2) and nuclear factor kappa B (NF-kB) genes that are involved in immune responses were analysed. For the in vitro model of HPBMs, nine men and nine women of childbearing age were selected and HPBMs were isolated from samples of the volunteers' peripheral blood. In women, blood was collected during the periovulatory period. The HPBMs were inoculated with S. aureus for 6 h and the supernatant was collected for the analysis of cytokines TNF-α, IL-6, IL-12; and GM-CSF, NO-2, and H2O2. The HPBMs were then removed for the analysis of 84 genes involved in the host's response to bacterial infections by RT-PCR array. GraphPad was used for statistical analysis with a p value < 0.05. RESULTS: Our data demonstrated that MPMs from sham males inoculated with S. aureus displayed higher concentrations of inflammatory cytokines and lower concentrations of IL-10, NO-2, and H2O2 when compared with MPMs from OQX males and females. A similar result was observed in the HPBMs of men when compared with those of women. Previous treatment with DHT in women HPBMs increased the production of pro-inflammatory cytokines and decreased the levels of IL-10, NO-2, and H2O2. The analysis of gene expression showed that DHT increased the activity of the TLR2 and NF-kB pathways in both MPMs and HPBMs. CONCLUSIONS: We found that DHT acts as an inflammatory modulator in the monocyte/macrophage response induced by S. aureus and females exhibit a better immune defence response against this pathogen.

Multidrug-Resistant Kocuria rosea and Methicillin-Resistant Staphylococcus aureus Co-Infection in a Nigerian Patient with COVID-19: A Case Report.

BACKGROUND Bacterial Infections, especially, of the respiratory system, have been reported as one of the medical concerns in patients with the Coronavirus Disease-2019 (COVID-19), particularly those with multiple co-morbidities. We present a case of a diabetic patient with co-infection of multi-drug-resistant Kocuria rosea and methicillin-resistant Staphylococcus aureus (MRSA) who contracted COVID-19. CASE REPORT A 72-year-old man with diabetes presented with symptoms including cough, chest pain, urinary incontinence, respiratory distress, sore throat, fever, diarrhea, loss of taste, and anosmia and was confirmed to have COVID-19. At admission, he was also found to have sepsis. MRSA was isolated in conjunction with another organism, resembling coagulase-negative Staphylococcus, which was misidentified using commercial biochemical testing systems. The strain was finally confirmed to be Kocuria rosea by 16S rRNA gene sequencing. Both strains were highly resistant to multiple classes of antibiotics, but the Kocuria rosea was resistant to all the cephalosporins, fluoroquinolones, and macrolides tested. The use of ceftriaxone and ciprofloxacin did not improve his condition, which ultimately led to his death. CONCLUSIONS This case report shows that the presence of multi-drug-resistant bacteria infections can be fatal in patients with COVID-19, especially in patients with other co-morbidities like diabetes. This case report also shows that biochemical testing may be inadequate in identifying emerging bacterial infections and there is a need to include proper bacterial screening and treatment in the management of COVID-19, especially in patients with other co-morbidities and with indwelling devices.

Treatment and outcome of gram-positive bacteremia in patients receiving extracorporeal membrane oxygenation.

BACKGROUND: While guidance exists for management of blood stream infections with various invasive devices, there are currently limited data to guide antibiotic selection and duration for bacteremia in patients receiving extracorporeal membrane oxygenation (ECMO). OBJECTIVE: To evaluate the treatment and outcomes of thirty-six patients with Staphylococcus aureus and Enterococcus bacteremia on ECMO support. METHODS: Blood culture data was retrospectively analyzed from patients with Staphylococcus aureus bacteremia (SAB) or Enterococcus bacteremia who underwent ECMO support between March 2012 and September 2021 at Brooke Army Medical Center. RESULTS: Of the 282 patients who received ECMO during this study period, there 25 (9%) patients developed Enterococcus bacteremia and 16 (6%) developed SAB. SAB occurred earlier in ECMO as compared to Enterococcus (median day 2 IQR (1-5) vs. 22 (12-51), p = 0.01). The most common duration of antibiotics was 28 days after clearance for SAB and 14 days after clearance for Enterococcus. 2 (5%) patients underwent cannula exchange with primary bacteremia, and 7 (17%) underwent circuit exchange. 1/3 (33%) patients with SAB and 3/10 (30%) patients with Enterococcus bacteremia who remained cannulated after completion of antibiotics had a second episode of SAB or Enterococcus bacteremia. CONCLUSION: This single center case series is the first to describe the specific treatment and outcomes of patients receiving ECMO complicated by SAB and Enterococcus bacteremia. For patients who remain on ECMO after completion of antibiotics, there is a risk of a second episode of Enterococcus bacteremia or SAB.

Staphylococcus aureus binding to Seraph® 100 Microbind® Affinity Filter: Effects of surface protein expression and treatment duration.

INTRODUCTION: Extracorporeal blood purification systems represent a promising alternative for treatment of blood stream infections with multiresistant bacteria. OBJECTIVES: The aim of this study was to analyse the binding activity of S. aureus to Seraph affinity filters based on heparin coated beads and to identify effectors influencing this binding activity. RESULTS: To test the binding activity, we used gfp-expressing S. aureus Newman strains inoculated either in 0.9% NaCl or in blood plasma and determined the number of unbound bacteria by FACS analyses after passing through Seraph affinity filters. The binding activity of S. aureus was clearly impaired in human plasma: while a percent removal of 42% was observed in 0.9% NaCl (p-value 0.0472) using Seraph mini columns, a percent removal of only 10% was achieved in human plasma (p-value 0.0934). The different composition of surface proteins in S. aureus caused by the loss of SarA, SigB, Lgt, and SaeS had no significant influence on its binding activity. In a clinically relevant approach using the Seraph® 100 Microbind® Affinity Filter and 1000 ml of human blood plasma from four different donors, the duration of treatment was shown to have a critical effect on the rate of bacterial reduction. Within the first four hours, the number of bacteria decreased continuously and the reduction in bacteria reached statistical significance after two hours of treatment (percentage reduction 64%, p-value 0.01165). The final reduction after four hours of treatment was close to 90% and is dependent on donor. The capacity of Seraph® 100 for S. aureus in human plasma was approximately 5 x 108 cells. CONCLUSIONS: The Seraph affinity filter, based on heparin-coated beads, is a highly efficient method for reducing S. aureus in human blood plasma, with efficiency dependent on blood plasma composition and treatment duration.

Success and failures in MRSA infection control during the COVID-19 pandemic.

Private sector facilities in the United States have experienced a resurgence of Methicillin-resistant Staphylococcus aureus (MRSA) hospital-onset infections during the COVID-19 pandemic, which eliminated all gains that were achieved over the last decade. The third quarter of 2021, the Standardized Infection Ratio for hospital onset MRSA bloodstream infections was 1.17, well above the baseline value of 1.0. In contrast, the Veterans Health Administration (VHA) has been able to maintain its mitigation efforts and low rates of MRSA hospital-onset infections through the second quarter of fiscal year 2022 (Mar. 31, 2022), the most recent available data. The difference may be explained not only by the VHA's use of uniform mitigating policies which rely on active surveillance and contact precautions, but also on the VAH's ability to maintain adequate staffing during the pandemic. Future research into MRSA mitigation is warranted and this data supports the need for healthcare system transformation.

Changes in the Protein Profile in Staphylococcal Strains from Patients Infected with the SARS-CoV-2 Virus.

Staphylococcus aureus strains are particularly often isolated from patients with SARS-CoV-2 infection. The aim of the current research was to determine whether the SARS-CoV-2 virus infection affects the protein profile of S. aureus. Bacteria were isolated from the forty swabs collected from the patients in the hospitals of the Pomeranian region. MALDI-TOF MS spectra were obtained using a Microflex LT instrument. Twenty-nine peaks were identified. The peak (2,430) is described here for the first time and was unique for the isolates from patients infected with the SARS-CoV-2 virus. These results support the hypothesis of bacterial adaptation to the conditions caused by viral infection.

Effect of Long-Term Use of Alcohol-Containing Handwashing Gels on the Biofilm-Forming Capacity of Staphylococcus epidermidis.

The spread of coronavirus disease 2019 (COVID-19) has promoted the use of hand sanitizers among the general population as recommended by health authorities. Alcohols, which are used in many hand sanitizers, have been shown to promotes the formation of biofilms by certain bacteria and to increase bacterial resistance to disinfection. We investigated the effect of continued use of alcohol-based gel hand sanitizer on biofilm formation by the Staphylococcus epidermidis resident strain isolated from the hands of health science students. Hand microbes were counted before and after handwashing, and the ability to produce biofilms was investigated. We found that 179 (84.8%) strains of S. epidermidis isolated from hands had the ability to form biofilm (biofilm-positive strains) in an alcohol-free culture medium. Furthermore, the presence of alcohol in the culture medium induced biofilm formation in 13 (40.6%) of the biofilm-negative strains and increased biofilm production in 111 (76.6%) strains, which were classified as low-grade biofilm-producing. Based on our findings, there is no clear evidence that the continued use of alcohol-based gels results in the selection of strains with the capacity to form biofilms. However, other disinfectant formulations that are more commonly used in clinical settings, such as alcohol-based hand-rub solutions, should be tested for their long-term effects.

Antimicrobial resistance prevalence of Escherichia coli and Staphylococcus aureus amongst bacteremic patients in Africa: a systematic review.

OBJECTIVES: Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region. METHODS: PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I2 index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations. RESULTS: Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I2 > 90%). CONCLUSION: The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.

Evaluating Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Nasal Screening as a Tool for Antimicrobial Stewardship.

INTRODUCTION: Initiation of broad-spectrum empiric antibiotics is common when infection is suspected in hospitalized adults. The benefits of early utilization of effective antibiotics are well documented. However, the negative effects of inappropriate antibiotic use have led to antimicrobial stewardship mandates. Recent data demonstrate the utility of methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nasal screening to steward anti-MRSA empiric antibiotics in pneumonia. We hypothesize that MRSA PCR nasal swabs would also be effective to rule out other MRSA infection to effectively limit unnecessary antibiotics for any infectious source. METHODS: We performed a single-center retrospective chart review of all adult patient encounters from October 2019-July 2021 with MRSA PCR nasal testing. We then reviewed all charts to evaluate for the presence of infections based on source cultures results, as the gold standard. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated from 2 × 2 contingency tables. RESULTS: Among all patients with MRSA nasal screening, 1189 patients had any infection. Prevalence of MRSA nasal carriage among patients screened was 12%. Prevalence of MRSA infection among all infections was 7.5%. MRSA nasal swabs demonstrated a negative predictive value of 100% for MRSA urinary tract infection, 97.9% for MRSA bacteremia, 97.8% for MRSA pneumonia, 92.1% for MRSA wound infection, and 96.6% for other MRSA infections. Overall, MRSA PCR nasal swabs had a sensitivity of 68.5%, specificity of 90.1%, positive predictive value of 23.7%, and negative predictive value of 98.5% for any infections. CONCLUSIONS: MRSA PCR nasal swabs have a high negative predictive value for all infections. Our data support the use of MRSA PCR nasal swabs to rule out MRSA infection and thereby allow early de-escalation of MRSA coverage in hospitalized patients requiring empiric antibiotics. Implementation of MRSA screening could decrease antibiotic-associated morbidity, resistance, and costs. More studies should be conducted to validate these results and support these findings.

Skin and soft tissue infections in the elderly.

PURPOSE OF REVIEW: To highlight the peculiarity of skin and soft tissue infections (SSTIs) in elderly patients and to provide useful elements for their optimal management. RECENT FINDINGS: In the COVID-19 era, early discharge from the hospital and implementation of outpatient management is of key importance. SUMMARY: Elderly patients are at high risk of SSTIs due to several factors, including presence of multiple comorbidities and skin factors predisposing to infections. Clinical presentation may be atypical and some signs of severity, such as fever and increase in C-reactive protein, may be absent or aspecific in this patients population. An appropriate diagnosis of SSTIs in the elderly is crucial to avoid antibiotic overtreatment. Further studies should explore factors associated with bacterial superinfections in patients with pressure ulcers or lower limb erythema. Since several risk factors for methicillin-resistant Staphylococcus aureus (MRSA) may coexist in elderly patients, these subjects should be carefully screened for MRSA risk factors and those with high risk of resistant etiology should receive early antibiotic therapy active against MRSA. Physicians should aim to several objectives, including clinical cure, patient safety, early discharge and return to community. SSTIs in the elderly may be managed using long-acting antibiotics, but clinical follow-up is needed.

Medical Face Masks Do Not Affect Acid-Base Balance Yet Might Facilitate the Transmission of Staphylococcus aureus in Hospital Settings during the COVID-19 Pandemic.

INTRODUCTION: Due to the SARS-CoV-2 coronavirus pandemic, the wearing of masks has become a common phenomenon. Most of the undesirable effects of using a protective face covering are usually related to the prolonged time of its wearing, and the adverse consequences of face coverings should be considered two-fold. The aim of the study was to evaluate the rate of contamination of the three types of face coverings (surgical, N95, and FFP2 masks) with the microorganism-aerobic bacteria, yeasts, and molds-after the 3 h exposure time. The study aimed to investigate the effects of wearing FFP2 masks (KN95) on respiratory function and the acid-base balance of the human body. RESULTS: The presence of S. aureus was confirmed in both nasal carriers and non-carriers which may demonstrate the cross-contamination and spread of this bacterium via hands. S. aureus was found on external and internal surfaces of face masks of each type, and therefore could also be transmitted via hands from external sources. The 3 h exposure time is not sufficient for Gram-negative rods and mold contamination. Moreover, there were no significant differences in most of the parameters studied between the first and second examinations, both in spirometry and capillary blood gas analysis (p > 0.05).

Tetrahedral Framework Nucleic Acids: A Novel Strategy for Antibiotic Treating Drug-Resistant Infections.

Antibiotic multiresistance (AMR) has emerged as a major threat to human health as millions of people die from AMR-related problems every year. As has been witnessed during the global COVID-19 pandemic, the significantly increased demand for antibiotics has aggravated the issue of AMR. Therefore, there is an urgent need to find ways to alleviate it. Tetrahedral framework nucleic acids (tFNAs) are novel nanomaterials that are often used as drug delivery platforms because of their structural diversity. This study formed a tFNAs-antibiotic compound (TAC) which has a strong growth inhibitory effect on Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) in vitro owing to the increased absorption of antibiotics by bacteria and improved drug movement across cell membranes. We established a mouse model of systemic peritonitis and local wound infections. The TAC exhibited good biosafety and improved the survival rate of severely infected mice, promoting the healing of local infections. In addition to the better transport of antibiotics to the target, the TAC may also enhance immunity by regulating the differentiation of M1 and M2 macrophages, providing a new option for the treatment of infections.

Staphylococcus aureus bacteremia in patients with SARS-CoV-2 infection.

OBJECTIVES: The aim was to compare the incidence of Staphylococcus aureus bacteremia in COVID-19 and non-COVID-19 adult patients during the pandemic period versus the previous two years. Also, we described the characteristics of both cohorts of patients in pandemic period to find differences. MATERIAL AND METHODS: Retrospective study in our tertiary-care centre reviewing S. aureus bacteremia episodes in COVID-19 and non-COVID-19 patients through clinical records and the Microbiology Department database. RESULTS: In 2018 and 2019, the incidence of S. aureus bacteremia episodes was 1.95 and 1.63 per 1000 admissions respectively. In the pandemic period, global incidence was 1.96 episodes per 1000 non-COVID-19 admissions and 10.59 episodes per 1000 COVID-19 admissions. A total of 241 bacteremia was registered during this pandemic period in 74 COVID-19 patients and in 167 non-COVID-19 patients. Methicillin resistance was detected in 32.4% and 13.8% of isolates from COVID-19 and non-COVID-19 patients respectively. In COVID-19 patients, mortality rates were significantly higher. CONCLUSIONS: We showed a significantly high rates of S. aureus bacteremia incidence in COVID-19 patients and higher methicillin resistance and 15-day mortality rates than in non-COVID-19 patients.