Platelets accumulate in lung lesions of tuberculosis patients and inhibit T-cell responses and Mycobacterium tuberculosis replication in macrophages.

Platelets regulate human inflammatory responses that lead to disease. However, the role of platelets in tuberculosis (TB) pathogenesis is still unclear. Here, we show that patients with active TB have a high number of platelets in peripheral blood and a low number of lymphocytes leading to a high platelets to lymphocytes ratio (PL ratio). Moreover, the serum concentration of different mediators promoting platelet differentiation or associated with platelet activation is increased in active TB. Immunohistochemistry analysis shows that platelets localise around the lung granuloma lesions in close contact with T lymphocytes and macrophages. Transcriptomic analysis of caseous tissue of human pulmonary TB granulomas, followed by Gene Ontology analysis, shows that 53 platelet activation-associated genes are highly expressed compared to the normal lung tissue. In vitro activated platelets (or their supernatants) inhibit BCG-induced T- lymphocyte proliferation and IFN-γ production. Likewise, platelets inhibit the growth of intracellular macrophages of Mycobacterium (M.) tuberculosis. Soluble factors released by activated platelets mediate both immunological and M. tuberculosis replication activities. Furthermore, proteomic and neutralisation studies (by mAbs) identify TGF-ß and PF4 as the factors responsible for inhibiting T-cell response and enhancing the mycobactericidal activity of macrophages, respectively. Altogether these results highlight the importance of platelets in TB pathogenesis.

A case of syphilis associated with immune reconstitution inflammatory syndrome and review of the literature.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) associated with syphilis has rarely been described in HIV-infected patients. Diagnosis can be challenging because it is not always possible to discern it from a recent infection or a worsening of an undiagnosed one. CASE PRESENTATION: An HIV-positive 42-year-old man with a poor compliance history of antiretroviral therapy presented at our unit and complained of ocular symptoms. Ocular syphilis diagnosis was posed after initial misdiagnosing with cytomegalovirus infection, and antiretroviral therapy compliance improved after switching to a bictegravir-based regimen. Despite intravenous (IV) penicillin, we observed an initial worsening with the appearance of new skin lesions, and IRIS syphilis was suspected. In the literature, 14 cases of IRIS syphilis are described, all regarding male patients. Seven were HIV naïve to therapy, and 7 HIV-experienced with poor therapy compliance. Basal syphilis serology was negative in ten, with subsequent seroconversion after the development of IRIS. IRIS-syphilis development was observed after a median time of 28 days from ART initiation; 10 cases were considered "unmasking-IRIS" and 4 "paradoxical-IRIS". Skin and ocular involvement were the most often reported. In most cases, it was not necessary to use a systemic steroid. A good outcome was reported in 12. CONCLUSIONS: Syphilis should be considered in differential diagnosis with other diseases associated with IRIS. A negative syphilis serology before beginning antiretroviral therapy could convey the impression that syphilis has been ruled out. Whereas a high index of suspicion should be maintained when symptoms suggestive of syphilis, such as ocular and skin manifestations, are noticed after therapy has begun.

HLA-E-restricted CD8+ T Lymphocytes Efficiently Control Mycobacterium tuberculosis and HIV-1 Coinfection.

We investigated the contribution of human leukocyte antigen A2 (HLA-A2) and HLA-E-restricted CD8+ T cells in patients with Mycobacterium tuberculosis and human immunodeficiency virus 1 (HIV-1) coinfection. HIV-1 downregulates HLA-A, -B, and -C molecules in infected cells, thus influencing recognition by HLA class I-restricted CD8+ T cells but not by HLA-E-restricted CD8+ T cells, owing to the inability of the virus to downmodulate their expression. Therefore, antigen-specific HLA-E-restricted CD8+ T cells could play a protective role in Mycobacterium tuberculosis and HIV-1 coinfection. HLA-E- and HLA-A2-restricted Mycobacterium tuberculosis-specific CD8+ T cells were tested in vitro for cytotoxic and microbicidal activities, and their frequencies and phenotypes were evaluated ex vivo in patients with active tuberculosis and concomitant HIV-1 infection. HIV-1 and Mycobacterium tuberculosis coinfection caused downmodulation of HLA-A2 expression in human monocyte-derived macrophages associated with resistance to lysis by HLA-A2-restricted CD8+ T cells and failure to restrict the growth of intracellular Mycobacterium tuberculosis. Conversely, HLA-E surface expression and HLA-E-restricted cytolytic and microbicidal CD8 responses were not affected. HLA-E-restricted and Mycobacterium tuberculosis-specific CD8+ T cells were expanded in the circulation of patients with Mycobacterium tuberculosis/HIV-1 coinfection, as measured by tetramer staining, but displayed a terminally differentiated and exhausted phenotype that was rescued in vitro by anti-PD-1 (programmed cell death protein 1) monoclonal antibody. Together, these results indicate that HLA-E-restricted and Mycobacterium tuberculosis-specific CD8+ T cells in patients with Mycobacterium tuberculosis/HIV-1 coinfection have an exhausted phenotype and fail to expand in vitro in response to antigen stimulation, which can be restored by blocking the PD-1 pathway using the specific monoclonal antibody nivolumab.

Direct-acting antivirals and visceral leishmaniasis: a case report.

BACKGROUND: Visceral leishmaniasis is a vector-borne parasitic disease caused by protozoa belonging to the genus Leishmania. The clinical presentation of visceral leishmaniasis strictly depends on the host immunocompetency, whereas depressive conditions of the immune system impair the capability to resolve the infection and allow reactivation from sites of latency of the parasite. CASE PRESENTATION: We describe a case of visceral leishmaniasis (VL) that occurred in a patient with chronic hepatitis C treated with direct-acting antiviral drugs (DAA). The hypothesized mechanism is the alteration of protective inflammation mechanisms secondary to DAA therapy. Downregulation of type II and III IFNs, their receptors, which accompany HCV clearance achieved during treatment with sofosbuvir and ribavirin might have a negative impact on a risk for reactivation of a previous Leishmania infection. We know indeed that IFN-γ is important to enhance killing mechanisms in macrophages, which are the primary target cells of Leishmania. CONCLUSION: Since VL is endemic in Sicily as well as in other countries of the Mediterranean basin, physicians should be aware of the possible unmasking of cryptic Leishmania infection by DAAs.

Intestinal Involvement in Kawasaki Disease.

OBJECTIVES: To describe a case of Kawasaki disease with intestinal involvement and to analyze other published reports to define clinical characteristics, diagnostic issues, and therapeutic approaches of gastrointestinal involvement in Kawasaki disease. STUDY DESIGN: A computerized search without language restriction was conducted using PubMed and SCOPUS. An article was considered eligible for inclusion in the systematic review if it reported data on patient(s) with intestinal involvement in Kawasaki disease. Our case was also included in the analysis. RESULTS: Thirty-three articles reporting 48 cases of Kawasaki disease with intestinal involvement were considered. Fever, abdominal pain, and vomiting were the most frequent symptoms observed and typical Kawasaki disease signs and symptoms appeared after intestinal complaints in all cases. Plain radiographs, ultrasonography, and computed tomography showed pseudo-obstruction as the most frequent sign of gastrointestinal involvement; 25 patients underwent surgery. Cardiac involvement was documented in 21 cases. All but three patients received medical treatment with immunoglobulin intravenous or aspirin. The outcome was good in 28 patients; 7 patients showed persistence of coronary artery abnormalities; 1 patient developed cyanosis, and later, left hand and forefoot gangrene; 3 patients died. CONCLUSIONS: The diagnosis and treatment of Kawasaki disease might be delayed if intestinal symptoms appear before the characteristic clinical features of Kawasaki disease, thus, increasing the risk of cardiac complications. Furthermore, patients may undergo unnecessary invasive procedures. Pediatricians and pediatric surgeons, therefore, should consider Kawasaki disease among diagnoses in children with fever, abdominal symptoms, and radiologic findings of pseudo-obstruction.

Bactibilia in diseases of the biliary tract and pancreatic gland in patients older than 80 years: a STROBE-retrospective cohort study in a teaching hospital in Italy.

Bile is a lipid-rich sterile solution produced in the liver that can be infected resulting in bactibilia. A higher incidence of postoperative infectious complications has been seen in patients with bactibilia. Recently, gram-negative bacteria have been linked to a tumor-associated inflammatory status. This study is a retrospective cohort study of 39 patients, who are over 80 years of age only (53.85% males and 46.15% females), hospitalized with diseases of the biliopancreatic system in one teaching hospital in Italy from January 2011 to December 2012 with a follow-up of 5 years. The most common biliary diseases after surgery were pancreatic head cancer (p < 0.0001) and gallbladder cancer (p = 0.0051), while the most common bacteria in the bile were E. coli (p = 0.0180) and Pseudomonas spp. (p < 0.0001). Uni- and multivariate linear correlation analysis revealed that patients with pancreatic head cancer had low survival times compared to patients with other diseases. Moreover, the bacterium type was a positive predictor of survival time compared to other variables. Our data confirm E. coli as a pathogen in patients with gallbladder and pancreatic cancer. Although the influence of bactibilia in developing surgical complications is limited, we consider that its composition is crucial to properly address the antibiotic treatment in biliary tract infections, especially in the elderly.

Human CD8 T lymphocytes recognize Mycobacterium tuberculosis antigens presented by HLA-E during active tuberculosis and express type 2 cytokines.

CD8 T cells contribute to protective immunity against Mycobacterium tuberculosis. In humans, M. tuberculosis reactive CD8 T cells typically recognize peptides associated to classical MHC class Ia molecules, but little information is available on CD8 T cells recognizing M. tuberculosis Ags presented by nonclassical MHC class Ib molecules. We show here that CD8 T cells from tuberculosis (TB) patients recognize HLA-E-binding M. tuberculosis peptides in a CD3/TCR αß mediated and CD8-dependent manner, and represent an additional type of effector cells playing a role in immune response to M. tuberculosis during active infection. HLA-E-restricted recognition of M. tuberculosis peptides is detectable by a significant enhanced ex vivo frequency of tetramer-specific circulating CD8 T cells during active TB. These CD8 T cells produce type 2 cytokines upon antigenic in vitro stimulation, help B cells for Ab production, and mediate limited TRAIL-dependent cytolytic and microbicidal activity toward M. tuberculosis infected target cells. Our results, together with the finding that HLA-E/M. tuberculosis peptide specific CD8 T cells are detected in TB patients with or without HIV coinfection, suggest that this is a new human T-cell population that participates in immune response in TB.

Validation of a Loop-Mediated Isothermal Amplification-Based Kit for the Detection of Legionella pneumophila in Environmental Samples According to ISO/TS 12869:2012.

Legionella pneumophila is a freshwater opportunistic pathogen and the leading cause of severe pneumonia known as Legionnaires' disease. It can be found in all water systems and survives in biofilms, free-living amoebae, and a wide variety of facilities, such as air conditioning and showers in hospitals, hotels and spas. The reference cultural method allows for the isolation and identification in many days, and in addition, it does not detect viable but rather non-culturable bacteria, increasing the risk of infection. In this context, a new LAMP-based (loop-mediated isothermal amplification) kit was developed, allowing for the rapid, sensitive, and labor-saving detection of L. pneumophila. The kit, "Legionella pneumophila Glow", was validated according to ISO/TS 12869:2012, testing sensitivity, inclusivity and exclusivity, and kit robustness. Sensitivity showed that the "Legionella pneumophila Glow" kit can detect up to 28 plasmid copies/µL. Robustness tests showed consistent results, with both contamination levels and the matrices used giving reproducible results. Furthermore, real samples were evaluated to compare the performance of the two methods. The LAMP kit "Legionella pneumophila Glow" proved a useful option for the rapid, efficient, and labor-saving screening of different typologies of water samples, offering significant advantages over the traditional method, as it is characterized by a high sensitivity, ease of use for laboratory testing, and a large reduction in analysis time, making it an asset to official controls.

The Impact of the Seasonal and Geographical Distribution of Tuberculosis in Sicily: A 6-Year Retrospective Study (2018-2023).

Background: Tuberculosis (TB) continues to be a major public health issue, with high mortality rates reported worldwide. It is worth noting that most of the hospitalizations for tuberculosis in the Sicilian region involve Italian-born individuals, underscoring the need to address this problem. Recent research on the geographic area and seasonality of infectious diseases, including tuberculosis, may aid in developing effective preventive measures. Objectives: This study aimed to evaluate the impact of the season and geographical area on tuberculosis disease prevalence in the Sicilian region. Methods: A retrospective study from January 2018 to May 2023 was conducted on patients with tuberculosis in the Sicilian region by analyzing computerized records on the Infectious Diseases Information System, currently named the Italian National Notification System (NSIS), of the Epidemiology Unit at Policlinico Paolo Giaccone University Hospital of Palermo and the Regional Reference Laboratory for Tuberculosis Surveillance and Control. Results: Eastern and Western Sicily were the geographical Sicilian areas with the highest frequency of patients with tuberculosis (52.2% and 42.6%, respectively). In comparison, Central Sicily had a significantly lower frequency of patients with tuberculosis (5.2%). Regarding the season, autumn was the season with the highest number of notification cases (28.9%), while spring was the season with the lowest frequency of patients with tuberculosis (19.7%). In autumn, we found significantly fewer patients with tuberculosis from Eastern Sicily (39.3%) and Central Sicily (1.5%), while Western Sicily had more patients with tuberculosis (59.3%). In spring, we found significantly more patients with tuberculosis from Eastern Sicily (64.1%), while Western and Central Sicily had significantly fewer patients with tuberculosis (23.9% and 12%, respectively). The presence of patients with tuberculosis did not significantly differ between geographical regions in summer and winter. Conclusions: Geographical area and seasonality significantly impact the distribution of tuberculosis cases in Sicily. These factors may be linked to different climatic conditions across the various geographical areas considered. Our findings suggest that climate can play a critical role in the spread of airborne infectious diseases, such as tuberculosis.

Microbial profile in bile from pancreatic and extra-pancreatic biliary tract cancer.

BACKGROUND: Dysbiotic biliary bacterial profile is reported in cancer patients and is associated with survival and comorbidities, raising the question of its effect on the influence of anticancer drugs and, recently, the suggestion of perichemotherapy antibiotics in pancreatic cancer patients colonized by the Escherichia coli and Klebsiella pneumoniae. OBJECTIVE: In this study, we investigated the microbial communities that colonize tumours and which bacteria could aid in diagnosing pancreatic and biliary cancer and managing bile-colonized patients. METHODS: A retrospective study on positive bile cultures of 145 Italian patients who underwent cholangiopancreatography with PC and EPC cancer hospitalized from January 2006 to December 2020 in a QA-certified academic surgical unit were investigated for aerobic/facultative-anaerobic bacteria and fungal organisms. RESULTS: We found that among Gram-negative bacteria, Escherichia coli and Pseudomonas spp were the most frequent in the EPC group, while Escherichia coli, Klebsiella spp, and Pseudomonas spp were the most frequent in the PC group. Enterococcus spp was the most frequent Gram-positive bacteria in both groups. Comparing the EPC and PC, we found a significant presence of patients with greater age in the PC compared to the EPC group. Regarding Candida spp, we found no significant but greater rate in the PC group compared to the EPC group (11.7% vs 1.96%). We found that Alcaligenes faecalis was the most frequent bacteria in EPC than the PC group, among Gram-negative bacterial species. CONCLUSIONS: Age differences in gut microbiota composition may affect biliary habitats in our cancer population, especially in patients with pancreatic cancer. Alcaligenes faecalis isolated in the culture of bile samples could represent potential microbial markers for a restricted follow-up to early diagnosis of extra-pancreatic cancer. Finally, the prevalence of Candida spp in pancreatic cancer seems to trigger new aspects about debate about the role of fungal microbiota into their relationship with pancreatic cancer.

Non-invasive assessment of liver steatosis and fibrosis in HIV/HCV- and HCV- infected patients.

BACKGROUND: Conflicting data have been reported on the prevalence of liver steatosis, its risk factors and its relationship with fibrosis in patients with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection or with HCV mono-infection. AIM: The study aims were to assess steatosis prevalence and its risk factors in both HCV groups. We also evaluated whether steatosis was linked with advanced fibrosis. Sixty-eight HIV/HCV co-infected and 69 HCV mono-infected patients were consecutively enrolled. They underwent liver ultrasonography and transient elastography. Bright liver echo-pattern was used to diagnose steatosis; advanced fibrosis was defined as liver stiffness ≥ 9.5 kPa and FIB-4 values ≥ 3.25. The optimal stiffness cut-off according to FIB-4 ≥ 3.25 was evaluated by ROC analysis. RESULTS: No significant difference was found in steatosis-prevalence between mono- and co-infected patients (46.3 vs. 51.4%). Steatosis was associated with triglycerides and impaired fasting glucose/diabetes in HCV mono-infected, with lipodystrophy, metabolic syndrome, total-cholesterol and triglycerides in co-infected patients. Stiffness ≥ 9.5 was significantly more frequent in co-infection (P < 0.003). Advanced fibrosis wasn't significantly associated with steatosis. The area under the ROC curve was 0.85 (95% CI 0.79-0.9). On multivariate analysis steatosis was associated with triglycerides in both HCV mono- and co-infected groups (P < 0.02; P < 0.03). CONCLUSION: Although steatosis was common in both HCV mono- and co-infected patients, it was not linked with advanced fibrosis. Triglycerides were independent predictors of steatosis in either of the HCV-groups. Dietary interventions and lifestyle changes should be proposed to prevent metabolic risk factors.

TTAS a new stilbene derivative that induces apoptosis in Leishmania infantum.

Leishmania parasites are able to undergo apoptosis (programmed cell death), similarly to mammalian cells. Recently it was demonstrated in vitro the anti-leishmanial effect of some natural and synthetic stilbenoids including resveratrol and piceatannol. In this study we evaluated the Leishmanicidal activity of a pool of stilbene derivatives which had previously shown high apoptotic efficacy against neoplastic cells. All the compounds tested were capable to decrease the parasite viability in a dose-dependent manner. Trans-stilbenes proved to be markedly more effective than cis-isomers. This was different from that observed in tumor cells in which cis-stilbenes were more potent cytotoxic agents. Trans-3,4',5-trimethoxy-3'-amino-stilbene (TTAS) was the most active stilbene showing in Leishmania infantum a LD(50) value of 2.6 µg/mL. In contrast TTAS showed a low toxicity when tested on normal hemopoietic cells. This compound induced apoptosis in parasites by disrupting the mitochondrial membrane potential. Moreover it shows the ability to block Leishmania parasites in G(2)-M phase of cell cycle in agreement with the data obtained by affinity chromatography that identify tubulin as the putative target of TTAS. In conclusion, our results indicate that some stilbene derivatives are highly effective as anti-leishmanial agents and TTAS represents a pro-apoptotic agent in Leishmania parasites that merit further in vivo investigation.

KPC - 3 Klebsiella pneumoniae ST258 clone infection in postoperative abdominal surgery patients in an intensive care setting: analysis of a case series of 30 patients.

BACKGROUND: Abdominal surgery carries significant morbidity and mortality, which is in turn associated with an enormous use of healthcare resources. We describe the clinical course of 30 Intensive Care Unit (ICU) patients who underwent abdominal surgery and showed severe infections caused by Klebsiella pneumoniae sequence type (ST) 258 producing K. pneumoniae carbapenemase (KPC-Kp). The aim was to evaluate risk factors for mortality and the impact of a combination therapy of colistin plus recommended regimen or higher dosage of tigecycline. METHODS: A prospective assessment of severe monomicrobial KPC-Kp infections occurring after open abdominal surgery carried out from August 2011 to August 2012 in the same hospital by different surgical teams is presented. Clinical and surgical characteristics, microbiological and surveillance data, factors associated with mortality and treatment regimens were analyzed. A combination regimen of colistin with tigecycline was used. A high dose of tigecycline was administered according to intra-abdominal abscess severity and MICs for tigecycline. RESULTS: The mean age of the patients was 56.6 ± 15 and their APACHE score on admission averaged 22.72. Twenty out of 30 patients came from the surgical emergency unit. Fifteen patients showed intra-abdominal abscess, eight anastomotic leakage, four surgical site infection (SSI) and three peritonitis. The overall crude ICU mortality rate was 40% (12 out of 30 patients). Twelve of the 30 patients were started on a combination treatment of high-dose tigecycline and intravenous colistin. A significantly lower mortality rate was observed among those patients compared to patients treated with approved dose of tigecycline plus colistin. No adverse events were reported with high doses of tigecycline. CONCLUSIONS: Critically-ill surgical patients are prone to severe post-surgical infectious complications caused by KPC-Kp. Timely microbiological diagnosis and optimizing antibiotic dosing regimens are essential to prevent worse outcomes. Further studies and well-controlled clinical trials are needed to define the optimal treatment of infections by KPC-Kp and, more generally, carbapenem-resistant bacteria.

Codon and Reverse Codon: A Theoretical Approach to Reinterpret the Genetic Code Table.

The genetic code table represents a fundamental scheme to translate a genetic code into a sequence of amino acids and, therefore, the possibility of operating the synthesis of all the proteins necessary for the life of organisms. Unfortunately, the various biological mechanisms are not fully clear. Hence, in this report, we analyzed the genetic code table and the amino acids codified by codons with an original theoretical and statistical approach based on the concept of permutations. We found an interesting reinterpretation of many codons, as reverse codons, which could help clarify some as-yet-unknown aspects in the field of protein folding.

Intestinal Lesions Due to Rhodococcus equi in a Patient With Advanced Retroviral Disease and Pulmonary Infection: A Case of Colonic Malakoplakia.

In humans, Rhodococcus equi (R. equi) is a zoonotic infection usually involving immunocompromised subjects, only rarely affecting immunocompetent subjects. Herein, we describe an R. equi infection in a 50-year-old Russian man with acquired immune deficiency syndrome (AIDS) who presented with pulmonary cavitary lesions and clinical manifestation of colonic malakoplakia. A colonoscopy examination showed ulceration and mucosal erosion, and the histological findings confirmed the colonic malakoplakia. The patient recovered from pulmonary and gastrointestinal disease after four weeks of antibiotic treatment with intravenous ciprofloxacin and oral azithromycin and also underwent subsequent long-term oral antibiotic treatment to achieve clinical and immune restoration after antiretroviral therapy. Infectious disease pathology subspecialties should always consider R. equi chronic infection as a cause of malakoplakia in patients with AIDS. As only a few cases of colonic malakoplakia associated with R. equi are reported in the literature, these cases are important to describe, especially for clinical and treatment management.