An unusual presentation of pulmonary aspergilloma and review of available literature.

INTRODUCTION: Aspergilloma is a non-invasive form of pulmonary aspergillosis usually presenting as a clump of mold in pre-existing cavitary lung disease. Aspergillus related lung diseases have been classified into four types, whose manifestation is often related to previous lung diseases and host immunologic status. CASE REPORT: Cases of cavitary pulmonary aspergillosis without any evidence of pre-existing cavities, are rarely reported. We present here a case of pulmonary aspergillosis in which cavity formation appeared apparently after the establishment of infection. CONCLUSIONS: The occurrence of atypical presentations and the importance of recognizing these unusual cases of pulmonary aspergilloma is discussed.

Role of the innate immune system in host defence against fungal infections.

OBJECTIVE: The objective of this narrative review is to present a summary of current knowledge of host-fungal pathogen interaction focusing on the importance of the innate immune system in host defense against invasive fungal infections. In addition, the emergence of drug resistance in the treatment of invasive fungal infections has also been highlighted. MATERIALS AND METHODS: A literature review was conducted to identify articles documenting the role of the host innate immune system against fungal pathogen and the emergence of drug resistance in the treatment of invasive fungal infections. RESULTS: In this review, we provide an update from the most recent studies on the role of the host innate immune system against fungal pathogen and we also highlight the mechanisms that these pathogens use to evade the innate immune system. CONCLUSIONS: This review highlights the existence of different cellular mechanisms that, following the recognition of fungal PAMPS, induce the production of different sets of defense factors. The development of new diagnostic methods and antifungal drugs along with a better understanding of the host immune response are key approaches to controlling invasive fungal infections.

Protective role of IL-18 in host defenses against group B Streptococcus.

The aim of this study was to investigate the role of IL-18, a member of the IL-1 family, in group B Streptococcus (GBS) infection. Both in a neonatal and adult model of GBS infection, IL-18-deficient animals were significantly more susceptible to infection than WT animals. The lack of IL18 was associated with a marked reduction in IFN-γ-levels after bacterial stimulation but did not play a significant role in the recruitment of PMN to sites of GBS infection. Collectively, our data document a fundamental function of IL-18 signaling in boosting the host immune responses against GBS infection.

The interleukin-1ß/CXCL1/2/neutrophil axis mediates host protection against group B streptococcal infection.

Previous studies have indicated that group B streptococcus (GBS), a frequent human pathogen, potently induces the release of interleukin-1ß (IL-1ß), an important mediator of inflammatory responses. Since little is known about the role of this cytokine in GBS disease, we analyzed the outcome of infection in IL-1ß-deficient mice. These animals were markedly sensitive to GBS infection, with most of them dying under challenge conditions that caused no deaths in wild-type control mice. Lethality was due to the inability of the IL-1ß-deficient mice to control local GBS replication and dissemination to target organs, such as the brain and the kidneys. Moreover, in a model of inflammation induced by the intraperitoneal injection of killed GBS, a lack of IL-1ß was associated with selective impairment in the production of the neutrophil chemokines CXCL1 and CXCL2 and in neutrophil recruitment to the peritoneal cavity. Decreased blood neutrophil counts and impaired neutrophil recruitment to the brain and kidneys were also observed during GBS infection in IL-1ß-deficient mice concomitantly with a reduction in CXCL1 and CXCL2 tissue levels. Notably, the hypersusceptibility to GBS infection observed in the immune-deficient animals was recapitulated by neutrophil depletion with anti-Gr1 antibodies. Collectively, our data identify a cytokine circuit that involves IL-1ß-induced production of CXCL1 and CXCL2 and leads the recruitment of neutrophils to GBS infection sites. Moreover, our data point to an essential role of these cells in controlling the progression and outcome of GBS disease.

The role of endosomal toll-like receptors in bacterial recognition.

BACKGROUND: Infections caused by extracellular Gram positive bacteria are still a major health problems. Better understanding of the mechanisms underlying immune responses to these organisms is key to develop pharmacological agents, including vaccines, to control these infections. OBJECTIVE AND PERSPECTIVES: The objective of this review is to highlight the importance of nucleic acid-sensing, intracellular Toll-like receptors in innate immune recognition and in host defenses against extracellular bacteria. CONCLUSIONS: Toll-like receptors 7 and 9 have a major role in inducing host-protective type I interferon responses in conventional dendritic cells in response to streptococci and other extracellular gram positive bacteria. Moreover an as yet unidentified MyD88-dependent receptor is likely responsible for proinflammatory cytokine induction in response to these pathogens.

Secondary hemophagocytic lymphohistiocytosis in zoonoses. A systematic review.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of histiocytes with uncontrolled hemophagocytosis and cytokines overproduction. The syndrome is characterized by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyperferritinemia. HLH can be either primary, with a genetic aetiology, or secondary, associated with malignancies, autoimmune diseases, or infections. AIM: To focus on secondary HLH complicating zoonotic diseases. MATERIALS AND METHODS: PubMed search of human cases of HLH occurring during zoonotic diseases was performed combining the terms (haemophagocytic or haemophagocytosis or hemophagocytosis or hemophagocytic or erythrophagocytosis or macrophage activation syndrome) with each one of the etiological agents of zoonoses. RESULTS: Among bacterial diseases, most papers reported cases occurring during brucellosis, rickettsial diseases and Q fever. Regarding viral diseases, most of the cases were reported in patients with avian influenza A subtype H5N1. Among the protozoan zoonoses, most of the cases were reported in patients with visceral leishmaniasis. Regarding zoonotic fungi, most of the cases were reported in AIDS patient with histoplasmosis. No cases of secondary HLH were reported in patient with zoonotic helminthes. CONCLUSIONS: Zoonotic diseases are an important cause of HLH. Secondary HLH can delay the correct diagnosis of the zoonotic disease, and can contribute to an adverse outcome.

Occurrence of Helicobacter pylori DNA in the coastal environment of southern Italy (Straits of Messina).

AIMS: The occurrence of Helicobacter pylori in the coastal zone of the Straits of Messina (Italy) as free-living and associated with plankton was studied. METHODS AND RESULTS: Monthly sampling of seawater and plankton was carried out from April 2002 to March, 2003. All environmental samples analysed by cultural method, did not show the presence of H. pylori. The DNA extracted from all environmental samples was tested by PCR by using primers for H. pylori 16S rRNA, ureA and cagA. 16S rRNA PCR yielded amplified products of 522-bp in 15 of 36 (41.7%) of the environmental samples. By using the ureA primers to amplify the urea signal sequences, the predicted PCR products of 491-bp were obtained from eight (22.2%) of 36 environmental samples. PCR with cagA primers yielded amplified products of 349-bp in DNA extracted of seven of 36 (19.4%) of the environmental samples. When 16S rRNA, ureA and cagA amplified gene sequences were aligned with H. pylori 26695 and J99 genome sequences, we obtained a percentage of alignment over 90%. CONCLUSIONS: The detection of H. pylori genes in marine samples allows us to consider the marine environment a possible reservoir for this pathogenic bacterium. SIGNIFICANCE AND IMPACT OF THE STUDY: The direct detection of H. pylori genes may be relevant in order to consider the marine environment as significant reservoir for this bacterium.

Beta 2 integrins are involved in cytokine responses to whole Gram-positive bacteria.

Proinflammatory cytokines have an important pathophysiologic role in septic shock. CD14 is involved in cytokine responses to a number of purified bacterial products, including LPS. However, little is known of monocyte receptors involved in cytokine responses to whole bacteria. To identify these receptors, human monocytes were pretreated with different mAbs and TNF-alpha was measured in culture supernatants after stimulation with whole heat-killed bacteria. Human serum and anti-CD14 Abs significantly increased and decreased, respectively, TNF-alpha responses to the Gram-negative Escherichia coli. However, neither treatment influenced responses to any of the Gram-positive bacteria tested, including group A and B streptococci, Listeria monocytogenes, and Staphylococcus aureus. Complement receptor type III (CR3 or CD18/CD11b) Abs prevented TNF-alpha release induced by heat-killed group A or B streptococci. In contrast, the same Abs had no effects when monocytes were stimulated with L. monocytogenes or S. aureus. Using either of the latter bacteria, significant inhibition of TNF-alpha release was produced by Abs to CD11c, one of the subunits of CR4. To confirm these blocking Ab data, IL-6 release was measured in CR3-, CR4-, or CD14-transfected Chinese hamster ovary cells after bacterial stimulation. Accordingly, streptococci triggered moderate IL-6 production (p < 0.05) in CR3 but not CD14 or CR4 transfectants. In contrast, L. monocytogenes and S. aureus induced IL-6 release in CR4 but not CR3 or CD14 transfectants. Collectively our data indicate that beta 2 integrins, such as CR3 and CR4, may be involved in cytokine responses to Gram-positive bacteria. Moreover, CD14 may play a more important role in responses to whole Gram-negative bacteria relative to Gram-positive ones.

Human monocyte receptors involved in tumor necrosis factor responses to group B streptococcal products.

Several group B streptococcal products have been previously found to stimulate human monocytes to produce tumor necrosis factor alpha. In order to identify the receptors involved in these responses, monocytes were stimulated with purified group- or type-specific carbohydrates or lipoteichoic acid in the presence of anti-receptor monoclonal antibodies, soluble CD14, or lipopolysaccharide-binding protein. Results indicate that CD14 plays an important role in tumor necrosis factor alpha responses to all of the stimuli tested. Moreover, both CD14 and complement receptor type 3 may be involved in responses to the group-antigen.

Role of IL-10 in a neonatal mouse listeriosis model.

This study was undertaken to test the hypothesis that altered IL-10 production plays a role in the increased susceptibility of neonates to listeriosis. Plasma IL-10 levels were measured in neonatal and adult mice at various times after infection with Listeria monocytogenes. Relative to adults, neonatal mice had markedly increased IL-10 levels early in the course of infection with Listeria using a 90% lethal dose. Higher neonatal IL-10 responses were also observed after injecting adults and pups with equal doses of killed organisms. Splenic macrophages from neonates produced higher IL-10 levels than those of adults after in vitro stimulation with killed bacteria, confirming in vivo observations. Moreover, IL-10 blockade had differential effects in neonates and adults infected with live Listeria. In adult mice, anti-IL-10 Abs decreased bacterial burden early in the course of infection, but were no longer effective at 6 days or later after challenge. In the pups, however, the same treatment had beneficial effects both early and late during infection and resulted in increased survival. Collectively, our data suggest that an overproduction of IL-10 by macrophages may at least partially explain the increased susceptibility of neonates to listeriosis, and provide further evidence that cytokine production is different in adults and neonates.

Medical management of the diabetic patient during podiatric surgery.

Diabetes mellitus commonly causes complications of the foot that can lead to surgery. The appropriate perioperative management of diabetic patients can reduce the morbidity and mortality associated with diabetic foot surgery and enhance wound healing. The authors review the effects of hyperglycemia, detail preoperative, intraoperative, and postoperative care, and describe anesthetic choices. An algorithm for management of hypoglycemia is offered.

High erythrocyte distribution values and possibilities of hemoglobinopathies.

Patients with hemoglobinopathies were observed to have high erythrocyte distribution widths. In a representative study of 800 patients, 31% of patients with high erythrocyte distribution widths were observed to have hemoglobinopathies by hemoglobin electrophoresis. The potential of erythrocyte distribution width as a means of incidental detection of hemoglobinopathies is discussed.