New Microbiologica最新文献

In this study, the potential effects of Tyrosine kinase 2 (TYK2) inhibition on COVID-19 outcomes was explored by assessing the causal association of the expression of TYK2 and COVID-19 outcomes with a two-sample Mendelian randomization (MR) design using summary statistics from genome-wide association studies (GWAS) and colocalization analysis. The MR analysis showed that the increase in gene expression of TYK2 was associated with a higher risk of critical illness COVID-19, hospitalized COVID-19, and SARS-CoV-2 infection with inverse-variance weighted method. The mediation analysis showed that the increased risk of COVID-19 by TYK2 expression is partly mediated by the increased C-C motif ligand 2 (CCL2) and intercellular adhesion molecule-1 (ICAM1) levels. The study provided suggestive evidence that TYK2 inhibition reduces the risk of COVID-19, and proposed TYK2 as a drug target for COVID-19 treatment.

This study aims to evaluate the distribution and antimicrobial resistance profiles of microorganisms isolated from blood cultures of patients hospitalised in intensive care units and wards of our hospital over a 2-year period, in light of European antimicrobial resistance data and country surveillance data. Blood cultures sent to the microbiology laboratory from the wards and intensive care units of our hospital between December 2020 and 2022 were retrospectively evaluated from the hospital automation system. The identification and the antimicrobial susceptibility of the isolates were done by the Phoenix 100 system (Becton Dickinson, USA). The results of antibiotic susceptibility were evaluated according to the criteria of the European Committee for Antimicrobial Susceptibility Testing (EUCAST). The blood culture results of 872 patients with pathogenic bacterial growth in their blood cultures were examined and evaluated. Taking into account World Health Organisation (WHO) surveillance reports, it appears that our hospital's antimicrobial resistance rates were higher than those reported by our country's data. Resistance profiles vary from country to country, city to city, and even among different hospitals in the same city. Monitoring of antimicrobial resistance, even at the hospital level, will contribute to programs to combat antimicrobial resistance both across the country and all around the world.

Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide; however, systemic infections such as bacteremia remain rare, particularly in immunocompetent individuals. This case report presents a rare instance of C. jejuni bacteremia in a 12-year-old girl undergoing chemotherapy for acute lymphoblastic leukemia (ALL), emphasizing the increased vulnerability of immunocompromised pediatric patients. The patient was admitted with febrile neutropenia, mucositis, and diarrhea. Blood cultures taken at admission signaled positive after 90 hours, and the isolate was identified as C. jejuni using MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing revealed sensitivity to erythromycin, which led to successful treatment and recovery following a 10-day antibiotic course. The case illustrates the pathophysiological role of chemotherapy-induced neutropenia and mucosal barrier damage in facilitating bacterial translocation and systemic infection. It also highlights diagnostic challenges due to the fastidious nature and slow growth of the organism, reinforcing the importance of rapid diagnostic tools and targeted therapy based on susceptibility results. In an era of rising antimicrobial resistance and growing populations of immunocompromised patients, this report underscores the critical need for heightened clinical awareness, robust laboratory support, and preventive public health strategies to mitigate the risk of severe Campylobacter infections in vulnerable groups.

In this study, we evaluated the in vitro antibacterial activity of cefepime/enmetazobactam and cefepime/zidebactam against well-characterized OXA-48-like producing Klebsiella pneumoniae clinical strains. Genomic analysis revealed that all strains carried class D carbapenemase including blaOXA-48 and blaOXA-181 as well as different ESBL genes. Our results demonstrated that both enmetazobactam and zidebactam significantly enhanced the bactericidal activity of cefepime in vitro. Based on these findings, we suggest that these combinations could be considered a valuable therapeutic approach for treatment of infections caused by OXA-48-producing K. pneumoniae.

Brucellosis is an endemic zoonotic infection in Turkey, capable of involving multiple organs and systems. While systemic symptoms are common, focal organ involvement may also occur. Isolated splenic infarction is a rare complication. We report a 27-year-old man with a one-week history of left upper abdominal pain, without fever or weight loss. Physical examination revealed closed Traube's space and left upper quadrant tenderness. Laboratory tests showed leukocytosis, thrombocytosis, and elevated transaminases. Brucella tube agglutination test was positive at 1/640. Abdominal CT demonstrated multiple hypodense, subcapsular, wedge-shaped lesions consistent with splenic infarction. Infective endocarditis, portal or splenic vein thrombosis, and rheumatologic disorders were excluded. The patient received a 12-week antibiotic regimen, resulting in clinical, laboratory, and radiological resolution. Splenic infarction secondary to brucellosis is infrequently described. Reported cases usually present with fever, abdominal pain, or systemic manifestations. Uniquely, our patient had only localized abdominal pain without fever or systemic features, underscoring the variable clinical spectrum of brucellosis. This case emphasizes the need to consider brucellosis in the differential diagnosis of splenic infarction, especially in endemic areas.

Paranasal sinus Fungus Ball (FB) is the most common non-invasive mycotic rhinosinusitis. It most frequently affects the maxillary and sphenoidal sinuses and the treatment of choice is Endoscopic Sinus Surgery (ESS). Although this pathology has been widely investigated throughout the years, some questions still remain unanswered. This study concentrates on assessing radiological and microbiological characteristics by examining a large number of cases treated in our centre. 235 cases of FB that underwent ESS in Fondazione I.R.C.C.S. Policlinico San Matteo di Pavia in the period comprised between January 2000 and May 2020 were collected. The surgical report, microbiological culture, histological report and preoperative Computed Tomography were analysed. FB was confirmed to affect more commonly the female population (68.22%). The maxillary (69.78%) and sphenoidal sinuses (27.23%) were the most frequent localizations. Interestingly, the microbiological reports showed different growth patterns as positive cultures from maxillary FB were reached in 21.52% of cases, while from sphenoidal FB in 45.76%. Different mycotic populations were found: Aspergillus fumigatus was isolated in 33 FB specimens, of which 63.3% in the maxillary sinus, while Aspergillus flavus was isolated in 10 specimens, of which 80% in the sphenoid sinus (p=0.017 and p=0.039 respectively). Radiologically, heterogeneous soft tissue density at sinus cavity (p=0.029) was more represented in patients with positive culture. This study analysed a large population and demonstrated differences in the growth pattern and subpopulation of fungi between differently localized FB, underlining a new characteristic of this pathology.

Background: The introduction of integrase strand transfer inhibitors (INSTIs) has transformed HIV therapy, offering high efficacy and tolerability. However, emerging evidence links INSTI exposure to weight gain. The long-term impact of switching from protease inhibitor (PI)-based to INSTI-based combined antiretroviral therapy (cART) on body composition and metabolic health remains incompletely understood.

Methods: We conducted a retrospective longitudinal study of 89 virologically suppressed people living with HIV (PLWH) followed from 2008 to 2021. All participants were on PI-based cART at baseline (T0). Between 2008 and 2013 (T1), a subset switched to a raltegravir-based INSTI regimen, with subsequent transitions to dolutegravir or bictegravir during follow-up (T2). Changes in body weight, body mass index (BMI), and metabolic parameters were compared between participants who remained on PI therapy and those who switched to any INSTI ("Ever INSTI").

Results: Over the full observation period, individuals who switched to INSTI-based therapy experienced significantly greater mean increases in body weight and BMI compared with those maintained on PI-based regimens. Immune recovery remained stable across groups, and metabolic safety appeared preserved. Within the INSTI class, participants with prolonged raltegravir exposure exhibited a trend toward greater long-term weight gain, though this finding should be interpreted cautiously due to the small subgroup size and potential residual confounding.

Conclusions: Switching from PI- to INSTI-based cART in virologically suppressed PLWH is associated with modest but sustained increases in body weight and BMI over time, without evident deterioration in metabolic health. These results support the favourable safety profile of INSTIbased regimens while underscoring the need for routine anthropometric monitoring and preventive lifestyle interventions during long-term therapy.

Human macrophages are credited with a dual ontogeny: tissue-resident macrophages (TRM) derive from embryonal structures and are endowed with both high resistance to pathogen-induced cell death and homeostatic proliferation in response to self-secreted cytokines. Conversely, circulating monocytes of bone marrow origin can differentiate into macrophages (MDM) upon migration to tissues in response to chemotactic signals triggered by infections or tissue damage. Both TRM and MDM can undergo differential cell activation programs, i.e., "M1/M2 polarization," leading to pro-inflammatory or anti-inflammatory and tissue-remodeling activities, respectively. We here will review the events following in vitro infection of human primary MDM by two unrelated RNA viruses: the human immunodeficiency virus (HIV), a retrovirus causing acquired immunodeficiency syndrome, and Zika virus (ZIKV), a flavivirus associated with microcephaly in newborns. M1 polarization of MDM before infection resulted in a clear-cut containment of the replicative capacity of both HIV-1 and ZIKV, whereas M2-MDM showed a complex modulation of HIV-1 replication and did not affect ZIKV production in human MDM. These findings suggest that M1 polarization of human macrophages contributes to the containment of diverse RNA virus infections, as here exemplified for HIV-1 and ZIKV, and could be harnessed to develop potential host-directed antiviral strategies.

Background: Methicillin-resistant Staphylococcus aureus has become significant due to its prevalence as one of the main causes of nosocomial infections, provoking both human and economic losses; therefore, a better understanding of its biology will allow the proposal of new strategies of control.

Objective: To analyze the metabolic profiles of two strains of Staphylococcus aureus under exposure to sub-inhibitory concentrations of oxacillin.

Method and materials: Methicillin-susceptible Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus strains were exposed to oxacillin at 0.125 mg/L; afterwards, tandem mass spectrometry was used to analyze their metabolic profiles (12 amino acid [AA]s and 28 acylcarnitine [AcC]s).

Results: Exposure to oxacillin in both strains generated osmolytes such as proline and carnitine, in response to osmotic stress generated from the damage on the cellular wall. Moreover, they presented a capacity to modify their intra-cellular composition of both amino acids and AcCs in response to exposure to the drug.

Conclusion: Exposure of MSSA and MRSA strains to oxacillin modifies their metabolome.

Opportunistic infections caused by Cryptococcus spp. are well-documented among people with HIV. However, the incidence of cryptococcosis has also recently risen among other immunocompromised patients. Here, we reported a rare case of primary cutaneous cryptococcosis in a 73-year-old man who had been taking corticosteroids long-term for rheumatoid arthritis (RA). Despite receiving antimicrobial treatment, he developed painful, non-healing ulceronecrotic lesions accompanied by haemorrhagic bullae on his right forearm and upper arm. Initially, it was thought that the patient had RA-associated vasculitis. A skin biopsy showed numerous small round structures that were stained with periodic acid-Schiff in the dermis. The wall of round structures had positive mucicarmine stain, consistent with the presence of mucopolysaccharides capsule of yeast. Also, the cryptococcal antigen test was positive in the serum. On the 14th day of fluconazole treatment, there was an improvement in the clinical picture, including a reduction in pain. However, he died from complications arising from his pre-existing systemic disease, specifically heart failure. This case highlights the importance of considering cutaneous fungal infections in immunocompromised patients with non-healing skin lesions despite antimicrobial treatment.