Cryptococcosis as an opportunistic infection in immunodeficiency secondary to paracoccidioidomycosis

We describe the case reports of two patients with immunodeficiency secondary to paracoccidioidomycosis (PCM) and opportunistic Cryptococcus neoformans infections. Secondary immunodeficiency likely occurred as a consequence of the intestinal loss of proteins and lymphocytes associated with malabsorption syndrome due to obstructed lymphatic drainage. Both patients had had severe abdominal involvement during the acute PCM disease. Immunological evaluation showed cellular and humoral immunity impairment. Cryptococcosis manifested as relatively well circumscribed lesions: osteolytic lesions of the skull in one patient, and pulmonary nodules in the other. The latter was treated surgically and with amphotericin B, whereas the other was treated with the combination amphotericin-B and flucytosine. Both patients had a good response to treatment with complete regression of the lesions. They have now 2 and 4 years of follow-up with maintenance therapy and no indication of reactivation of the infection. PCM also did not reactivate. The clinical and immunological characteristics of these patients are discussed and compared to the opportunistic C. neoformans infections of AIDS and transplant patients.     

Prevalence of pulmonary mycoses in smear-negative patients with suspected tuberculosis in the Brazilian Amazon

BackgroundPulmonary mycoses resemble clinically and radiologically chronic pulmonary tuberculosis. Studies describing the prevalence, etiology and clinical features of pulmonary mycosis are of crucial importance in the Brazilian Amazon.AimsTo estimate the frequency of pulmonary mycoses in smear-negative tuberculosis patients; to describe their demographic, epidemiological, and clinical characteristics; and to evaluate diagnostic methods.MethodsA cross-sectional study was conducted at two tuberculosis reference institutions in Amazonas, Brazil. We included 213 patients and collected clinical data, blood and induced sputum to perform serological, direct microscopy, microbiologic culture and PCR-based assays to identify infections caused by Aspergillus fumigatus, Paracoccidioides brasiliensis, Histoplasma capsulatum, Cryptococcus, and HIV. Chest computed tomography was also performed.ResultsPulmonary mycoses were diagnosed in 7% (15/213) of the cases, comprising ten aspergillosis cases, three cases of paracoccidioidomycosis and one case each of histoplasmosis and cryptococcosis. Among the patients with pulmonary mycoses, 86.7% were former tuberculosis patients. The most significant clinical characteristics associated with pulmonary mycoses were cavity-shaped lung injuries, prolonged chronic cough and hemoptysis.ConclusionsOur study confirmed the high prevalence of pulmonary mycoses in smear-negative tuberculosis patients in the Brazilian Amazon.     

Analysis of Invariant Natural Killer T Cells in Human Paracoccidioidomycosis

Invariant natural killer T (iNKT) cells are capable of recognizing lipid antigens and secreting Th1/Th2 cytokines. Deficiency in iNKT cell number or function has been partially implicated in susceptibility to some infectious diseases, such as tuberculosis. We evaluated iNKT cells in paracoccidioidomycosis, another chronic granulomatous disease endemic in Latin America. iNKT cells were detected using PBS57-loaded tetramer staining and flow cytometry. Circulating iNKT cell numbers were similar among healthy individuals who had previously been cured of paracoccidioidomycosis (susceptible individuals, n = 7) and healthy Paracoccidioides brasiliensis-infected (n = 5) and non-infected individuals (n = 5). iNKT from all three groups expanded similarly upon α-GalCer and a synthetic analog (OCH) stimulation. IFN-γ was the dominant cytokine produced both by ex vivo and by expanded iNKT cells, followed by IL-4 and IL-10, in the three groups. No deficit in the monocyte expression of CD1d was detected. In conclusion, individuals who had developed paracoccidioidomycosis in the past have no impairment in iNKT number, expansion capacity, and cytokine secretion.     

Persistent bacterial infections: the interface of the pathogen and the host immune system

Persistent bacterial infections involving Mycobacterium tuberculosis, Salmonella enterica serovar Typhi (S. typhi) and Helicobacter pylori pose significant public-health problems. Multidrug-resistant strains of M. tuberculosis and S. typhi are on the increase, and M. tuberculosis and S. typhi infections are often associated with HIV infection. This review discusses the strategies used by these bacteria during persistent infections that allow them to colonize specific sites in the host and evade immune surveillance. The nature of the host immune response to this type of infection and the balance between clearance of the pathogen and avoidance of damage to host tissues are also discussed.     

Immunization with heat‐inactivated Staphylococcus aureus induced an antibody response mediated by IgG1 and IgG2 in patients with recurrent tonsillitis

Currently Staphylococcus aureus is the predominant pathogen isolated from the respiratory tract of patients with recurrent tonsillitis. Because of an increase in multi‐drug resistant strains of S. aureus, there is a pressing need for effective treatments and preventive approaches to reduce the risk of invasive and life‐threatening infections. A preventive vaccine against S. aureus would have a tremendous clinical impact. However, multiple clinical trials have failed to identify an agent that can induce protective responses. Most trials have been based on subunit vaccines using one or a few purified antigens, which may not be enough to confer protection. Here, the impact of a whole‐cell vaccine comprised of heat‐inactivated S. aureus was investigated in patients with RT. The vaccine was well tolerated and had no significant local or systemic reactions. Immunization with heat‐inactivated S. aureus elicited a significant antibody response characterized by production of IgG1 and IgG2 antibodies and, to a lesser extent, of IgA antibodies. Notably, this response was associated with an important decrease in the incidence of tonsillitis and bacterial colonization of the oropharyngeal mucosa. Our results show that whole‐cell inactivated S. aureus is safe and capable of evoking specific antibody responses in patients with recurrent tonsillitis.     

Neoplasia and paracoccidioidomycosis

Published studies on the association between cancer and paracoccidioidomycosis consist either isolated cases or clinical data based on hospital cohorts of paracoccidioidomycosis. The frequency of neoplasia in series of ≥80 patients with paracoccidioidomycosis ranges from 0.16 to 14.1%, mean of 3.96%. There are only two retrospective controlled studies, one of them showing greater incidence of carcinoma in biopsy and necropsy samples of paracoccidioidomycosis (12 cases in 147 patients with the mycosis: 8.2%) than in the necropsies of the control group (320 cases in 7,302 necropsies: 4.9%). In the other, 22,409 autopsies were reviewed and 4,372 cases of cancer were found; of the 85 patients with paracoccidioidomycosis, 12 were diagnosed with cancer. No differences were observed in the frequency of malignancies between the group of patients with paracoccidioidomycosis (14.1%) and the control group (19.5%). Considering all the reported cases, carcinoma was more frequent than hematological malignancies, and was more often found at the same site or in a neighboring site affected by the mycosis, usually occurring after the diagnosis of the mycosis. Commonly, the basic cause of death was related to secondary infections or neoplasia. Lymphoma was associated with poorly organized rich in fungi granuloma. The clinical course and mortality were related to the cancer evolution or secondary infections and was worse in lymphoid series, metastatic carcinoma or in patients under cytotoxic chemotherapy. Additionally, as in several cases the clinical and histopathological data may mimick neoplasia, the correct diagnosis of both diseases is essential to guarantee an early and safe intervention.     

Molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus strains for clinical medicine

Infections caused by methicillin-resistant S. aureus strains are mainly associated with a hospital setting. However, nowadays, the MRSA infections of non-hospitalized patients are observed more frequently. In order to distinguish them from hospital-associated methicillin-resistant S. aureus (HA-MRSA) strains, given them the name of community-associated methicillin-resistant S. aureus (CA-MRSA). CA-MRSA strains most commonly cause skin infections, but may lead to more severe diseases, and consequently the patient’s death. The molecular markers of CA-MRSA strains are the presence of accessory gene regulator (agr) of group I or III, staphylococcal cassette chromosome mec (SCCmec) type IV, V or VII and genes encoding for Panton–Valentine leukocidin (PVL). In addition, CA-MRSA strains show resistance to β-lactam antibiotics. Studies on the genetic elements of CA-MRSA strains have a key role in the unambiguous identification of strains, monitoring of infections, improving the treatment, work on new antimicrobial agents and understanding the evolution of these pathogens.     

Polyserositis in a patient with acute paracoccidioidomycosis and hepatosplenic schistosomiasis

A severe case of juvenile paracoccidioidomycosis (PCM), manifested as cholestatic jaundice, lymphnode enlargement and an unusual form of polyserositis, associated with portal hypertension secondary to schistosomiasis, as well as bactermias caused byE. coli andS. aureus and post-transfusional hepatitis C is reported. Temporary unresponsiveness of in vivo and in vitro cellular immune responses toP. brasiliensis were registered. The authors discuss the possible interference of either agent in the host immune response, thus explaining the severity of PCM in the present case.     

Diagnosis of pseudomembranous colitis.

Twenty-eight patients with histologically proved pseudomembranous colitis have been seen in one hospital since July 1975. All patients with the disease had received antibiotics, six for infections not requiring operations; the other 22 cases all occurred after major surgery. All the patients had diarrhoea; six patients also had fever with clinical signs of sepsis, and three had abdominal pain thought to be due to anastomotic dehiscence after colonic resection. Pseudomembranous colitis was associated with white blood counts over 15 000/mm3 in 17 patients and albumin concentrations of less than 30 g/1 in 18. Pseudomembranous colitis was an incidental finding at necropsy in two of six patients who had not had an operation. Of the 22 patients who had had major surgery, nine died from this complication; in all except two of these cases the diagnosis was made only at necropsy. If pseudomembranous colitis is suspected on clinical grounds or if there is an unexplained complication after colorectal surgery repeat sigmoidoscopy and testing for faecal toxins should be carried out to establish the diagnosis so that prompt supportive treatment can be given.     

Animal Models and Antifungal Agents in Paracoccidioidomycosis: An Overview

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The morbidity and mortality associated with paracoccidioidomycosis necessitate our understanding of fungal pathogenesis and discovering of new agents to treat this infection. Animal models have contributed much to the knowledge of fungal infections and their corresponding therapeutic treatments. This is true for animal models of the primary fungal pathogens such as P. brasiliensis. This review describes the development, details and utility of animal models of paracoccidioidomycosis for studying and developing the current antifungal agents used for therapy of this fungal disease and novel agents with antifungal properties against P. brasiliensis.     

一株牙鲆源黏质沙雷氏菌YP1的分离鉴定及致病性分析

黏质沙雷氏菌(Serratia marcescens)是引起人类、动物及植物感染的重要条件致病菌,但其作为鱼类致病菌却鲜有报道。【目的】本研究以从患病牙鲆(Paralichthys olivaceus)病灶处分离的一株黏质沙雷氏菌YP1为研究对象,分析黏质沙雷氏菌对鱼类的致病性及对疾控的影响。【方法】利用形态学、分子生物学及生理生化实验综合鉴定菌株YP1;利用菌株YP1进行人工感染实验、组织病理实验及药敏试验,研究其感染症状、组织病理学、毒力和药物敏感性。【结果】分离自患病牙鲆体表溃疡病灶处的菌株YP1鉴定为黏质沙雷氏菌。感染实验结果显示,牙鲆和斑马鱼的半数致死量(LD₅₀)分别为3.44×10⁷CFU/g和6.28×10⁵CFU/g,除牙鲆外菌株YP1对其他鱼类也具有高致病性;菌株YP1主要导致牙鲆腹水,同时伴有呼吸急促、摄食减弱、脱肛、白便、鳃缺血及多脏器膨大出血等症状,并随着感染时间的延长对脏器损伤呈加重趋势。病理组织切片结果显示,菌株YP1对牙鲆鳃、肠、肝、脾、肾、心均造成损伤。药敏试验结果表明,YP1对左氧氟沙星、诺氟沙星等14种药物敏感;但对氨苄西林、头孢拉定等19种药物具有耐药性。【结论】本研究结果证实了黏质沙雷氏菌是能导致牙鲆腹水病的一种病原菌,同时对其他鱼类也具高致病性,为该菌感染鱼类导致疾病的检测、鉴别和防治提供科学依据。     

Prevalence of paracoccidioidomycosis in hospitalized adults in Rio de Janeiro (RJ) Brazil

Double immunodiffusion were used as screening test for the diagnosis of paracoccidioidomycosis. Five hundred hospitalized adults from general (150 patients — group I) and from a specialized chest disease hospital (350 patients — group II), were tested. All of them were without definitive etiological diagnosis and clinical specimens were obtained from the patients with positive serology. Testing sera obtained from 150 patients of the group I, fifty six cases of paracoccidioidomycosis were diagnosed. Specimens for mycological examination were subsequently obtained from 50 of these patients; P. brasiliensis could be recovered in 49 (98%). Fundamental importance was the finding of 17 (4.8%) cases of paracoccidioidomycosis among the 350 patients referred from a chest disease hospital (group II). Serological evidence of paracoccidioidomycosis found in 73 (14.6%) of the 500 screened patients, indicates a relatively high prevalence of this mycosis in adults patients admitted to several hospitals in RJ. These data probably do not reflect the real prevalence of paracoccidioidomycosis in RJ and should be considered as a gross underestimation. Thus, attention should also be paid to juvenile forms and DID could be of a great value in screening these cases too.This work forms part of the thesis A importância das técnicas de imunoprecipitação na triagem e diagnóstico da paracoccidioidomicose, histoplasmose e aspergilose. Estudo em população hospitalar do RJ. M. Phil. on Parasite Biology, Instituto Oswaldo Cruz, RJ — 1984.     

Clinical Performance of a New Soluble CD14-Subtype Immunochromatographic Test for Whole Blood Compared with Chemiluminescent Enzyme Immunoassay: Use of Quantitative Soluble CD14-Subtype Immunochromatographic Tests for the Diagnosis of Sepsis

We previously reported that a soluble CD14-subtype (sCD14-ST) immunochromatographic test (ICT) for plasma is more convenient than chemiluminescent enzyme immunoassay (CLEIA), but plasma separation makes bedside measurements difficult. We developed a new sCD14-ST ICT for whole blood and investigated whether quantitative determinations of sCD14-ST by ICT were useful for diagnosing sepsis and severe sepsis/septic shock. We studied 20 patients who fulfilled two or more systemic inflammatory response syndrome (SIRS) criteria and 32 patients who had been diagnosed with sepsis or severe sepsis/septic shock. Whole blood was collected on day 0 (on admission) and day 7, and the sCD14-ST concentration was quantitatively measured by CLEIA and ICT for whole blood. The patients’ Acute Physiology and Chronic Health Evaluation (APACHE) II, Sequential Organ Failure Assessment (SOFA), and Mortality in Emergency Department Sepsis (MEDS) scores were also calculated. The cut-off values obtained by the quantitative measurements made by ICT were 464.5 pg/mL for sepsis and 762.7 pg/mL for severe sepsis/septic shock (P < 0.0001). A Bland–Altman plot showed that no fixed bias or proportional bias was detected between CLEIA and quantitative ICT for whole blood. sCD14-ST concentrations were significantly correlated with APACHE II, SOFA, and MEDS scores (P < 0.0001). These results suggest that the new sCD14-ST ICT for whole blood may be a useful tool for the convenient, rapid bedside diagnosis and treatment of sepsis.     

A murine pneumonia model to study pathogenesis of <Emphasis Type="Italic">Stenotrophomonas maltophilia</Emphasis>

Early attempts to develop an animal model of infection appeared to support the hypothesis that Stenotrophomonas maltophilia does not cause serious sepsis when bacteria are intravenously administered to mice. This species has also been implicated in an increasing number of infections such as, bacteremia, endocarditis, ophthalmological syndromes, skin lesions, urinary, respiratory tract and gastrointestinal infections. Despite this clinical importance, the mechanisms involved in the pathogenesis of S. maltophilia infections have not been elucidated and the virulence factors of importance in the pathogenesis of S. maltophilia associated pulmonary infection remain to be characterized. The purpose of this study was to establish an infection model using 5 clinical isolates of S. maltophilia in a mouse pneumonia model. All strains were able to establish themselves in respiratory tract with peak of infection occurring at 24 h post infection. The strains were able to cause neutrophil influx, were taken up and intracellularly killed by alveolar macrophages except Sm2 that persisted for a slightly longer time in the macrophages. All strains were resistant to lytic action of serum and survived in blood confirming their ability to cause bacteremia. The strains were cleared from spleen and liver by 7th and 4th day but caused tissue damage that was measured in terms of lipid peroxidation, lactate dehydrogenase activity and histopathological examination of lung tissue homogenate. All strains caused interstitial pneumonitis in lungs of mice.     

Therapeutic applications of lysostaphin against Staphylococcus aureus

Staphylococcus aureus, an opportunistic pathogen, causes diverse community and nosocomial-acquired human infections, including folliculitis, impetigo, sepsis, septic arthritis, endocarditis, osteomyelitis, implant-associated biofilm infections and contagious mastitis in cattle. In recent days, both methicillin-sensitive and methicillin-resistant S. aureus infections have increased. Highly effective anti-staphylococcal agents are urgently required. Lysostaphin is a 27 kDa zinc metallo antimicrobial lytic enzyme that is produced by Staphylococcus simulans biovar staphylolyticus and was first discovered in the 1960s. Lysostaphin is highly active against S. aureus strains irrespective of their drug-resistant patterns with a minimum inhibitory concentration of ranges between 0·001 and 0·064 μg ml⁻¹. Lysostaphin has activity against both dividing and non-dividing S. aureus cells; and can seep through the extracellular matrix to kill the biofilm embedded S. aureus. In spite of having excellent anti-staphylococcal activity, its clinical application is hindered because of its immunogenicity and reduced bio-availability. Extensive research with lysostaphin lead to the development of several engineered lysostaphin derivatives with reduced immunogenicity and increased serum half-life. Therapeutic efficacy of both native and engineered lysostaphin derivatives was studied by several research groups. This review provides an overview of the therapeutic applications of native and engineered lysostaphin derivatives developed to eradicate S. aureus infections.     

Enzyme-linked immunosorbent assay (ELISA) in the paracoccidioidomycosis

An enzyme-linked immunosorbent assay (ELISA) for detection and quantification of antibodies antiParacoccidioides brasiliensis is described. Polystyrene plates have been used as solid phase to absorb P. brasiliensis metabolic yeast phase antigen. Twenty sera of proven paracoccidioidomycosis, 11 of histoplasmosis due Histoplasma capsulatum, 20 of aspergillosis and 20 human normal sera were tested. Ninety-five percent of the paracoccidioidomycosis sera had O.D. superior to 0.150 (from 0.163 to 2.650) at 1/400 serum dilution. ELISA assay was compared with counterimmunoelectrophoresis and erythro-immunoassay tests; a correlation was observed only with erythro-immunoassay. ELISA test should give new perspectives for the serodiagnosis of paracoccidioidomycosis.     

Case–Case Comparison of Candida auris Versus Other Candida Species Bloodstream Infections: Results of an Outbreak Investigation in Colombia

Background

Candida auris is an emerging multidrug-resistant yeast that causes outbreaks in healthcare settings around the world. In 2016, clinicians and public health officials identified patients with C. auris bloodstream infections (BSI) in Colombian healthcare facilities. To evaluate potential risk factors and outcomes for these infections, we investigated epidemiologic and clinical features of patients with C. auris and other Candida species BSI.

Methods

We performed a retrospective case-case investigation in four Colombian acute care hospitals, defining a case as Candida spp. isolated from blood culture during January 2015–September 2016. C. auris BSI cases were compared to other Candida species BSI cases. Odds ratio (OR), estimated using logistic regression, was used to assess the association between risk factors and outcomes.

Results

We analyzed 90 patients with BSI, including 40 with C. auris and 50 with other Candida species. All had been admitted to the intensive care unit (ICU). No significant demographic differences existed between the two groups. The following variables were independently associated with C. auris BSI:?≥?15 days of pre-infection ICU stay (OR: 5.62, CI: 2.04–15.5), evidence of severe sepsis (OR: 3.70, CI 1.19–11.48), and diabetes mellitus (OR 5.69, CI 1.01–31.9).

Conclusion

Patients with C. auris BSI had longer lengths of ICU stay than those with other candidemias, suggesting that infections are acquired during hospitalization. This is different from other Candida infections, which are usually thought to result from autoinfection with host flora.

     

Paracoccidioidomicosis en pediatría: descripción de 4 casos

BackgroundParacoccidioidomycosis is the most frequent systemic mycosis in Latin America, caused by the dimorphic fungus Paracoccidioides. Paracoccidioidomycosis in children is uncommon. Our aim is to describe clinical features of patients who had a confirmed diagnosis of paracoccidioidomycosis in our hospital in the last 10 years.Case reportsWe describe 4 cases of paracoccidioidomycosis in previously healthy children from the north of our country. Diagnoses were made by biopsy or culture.ConclusionsThe diagnosis of paracoccidioidomycosis should be considered in a patient coming from regions where Paracoccidioides is endemic, and presenting with a lymphoproliferative syndrome, anemia, eosinophilia and hypergammaglobulinemia.     

Intestinal microsporidiosis in India: A two year study

Intestinal parasitic pathogens in HIV/AIDS patients include Cryptosporidium sp, Cystoisospora sp, microsporidia and less commonly other parasites. The two most common microsporidia causing intestinal infection are Enterocytozoon bieneusi and Encephalitozoon intestinalis. Most of the Indian studies for intestinal parasitic infections in HIV/AIDS patients have not included microsporidia, due to difficult staining and identification of the parasite. The aim of the present study was to find the prevalence of intestinal microsporidiosis and their species identification along with correlation of CD4 count with parasite positivity and diarrhoea in HIV positive individuals. Stool samples of 363 individuals including 125 HIV seropositive patients with diarrhoea, 158 HIV seropositive patients without diarrhoea, 55 HIV seronegative patients with diarrhoea and 25 healthy controls were obtained from various out-patient departments and in-patients admitted to a tertiary care hospital from August 2008 to October 2009. The stool samples were subjected to examination by wet mount, modified acid fast stain for coccidian parasites and multiplex nested PCR for microsporidia. The overall prevalence of all intestinal parasites among HIV patients in our study was 26.5%. The prevalence of intestinal parasitic pathogens in HIV positive patients with diarrhoea was 43.2%. Microsporidia were the most common parasites detected (14%) in all patients, while in HIV infected patients 15.9% patients had microsporidia infection. The most common species causing intestinal microsporidiosis in our study was E. intestinalis (10.5%). In HIV seropositive individuals with diarrhoea, E. intestinalis was 20.8% and E. bieneusi 8.0% while in HIV-seropositive individuals without diarrhoea, E. intestinalis was 3.8% and E. bieneusi 1.9%. E. intestinalis was present in 10.9% of HIV negative individuals with diarrhoea in whom E. bieneusi was not found. There was a significant association between CD4 count ≤ 200/μl and intestinal parasite positivity. Thus, it can be concluded that intestinal microsporidiosis is under reported but an important disease in India. The predominant species in our study is E. intestinalis , in contrast to other parts of the world where E. bieneusi is more common.     

The circulatory small non-coding RNA landscape in community-acquired pneumonia on intensive care unit admission

Community-acquired pneumonia (CAP) is a major cause of sepsis. Despite several clinical trials targeting components of the inflammatory response, no specific treatment other than antimicrobial therapy has been approved. This argued for a deeper understanding of sepsis immunopathology, in particular factors that can modulate the host response. Small non-coding RNA, for example, micro (mi)RNA, have been established as important modifiers of cellular phenotypes. Notably, miRNAs are not exclusive to the intracellular milieu but have also been detected extracellular in the circulation with functional consequences. Here, we sought to determine shifts in circulatory small RNA levels of critically ill patients with CAP-associated sepsis and to determine the influence of clinical severity and causal pathogens on small RNA levels. Blood plasma was collected from 13 critically ill patients with sepsis caused by CAP on intensive care unit admission and from 5 non-infectious control participants. Plasma small RNA-sequencing identified significantly altered levels of primarily mature miRNAs in CAP relative to controls. Pathways analysis of high or low abundance miRNA identified various over-represented cellular biological pathways. Analysis of small RNA levels against common clinical severity and inflammatory parameters indices showed direct and indirect correlations. Additionally, variance of plasma small RNA levels in CAP patients may be explained, at least in part, by differences in causal pathogens. Small nuclear RNA levels were specifically altered in CAP due to Influenza infection in contrast to Streptococcus pneumoniae infection. Pathway analysis of plasma miRNA signatures unique to Influenza or Streptococcus pneumoniae infections showed enrichment for specific proteoglycan, cell cycle, and immunometabolic pathways.