Fucose Ameliorates Tritrichomonas sp.-Associated Illness in Antibiotic-Treated Muc2-/- Mice.

The mucus layer in the intestine plays a critical role in regulation of host-microbe interactions and maintaining homeostasis. Disruptions of the mucus layer due to genetic, environmental, or immune factors may lead to inflammatory bowel diseases (IBD). IBD frequently are accompanied with infections, and therefore are treated with antibiotics. Hence, it is important to evaluate risks of antibiotic treatment in individuals with vulnerable gut barrier and chronic inflammation. Mice with a knockout of the Muc2 gene, encoding the main glycoprotein component of the mucus, demonstrate a close contact of the microbes with the gut epithelium which leads to chronic inflammation resembling IBD. Here we demonstrate that the Muc2-/- mice harboring a gut protozoan infection Tritrichomonas sp. are susceptible to an antibiotic-induced depletion of the bacterial microbiota. Suppression of the protozoan infection with efficient metronidazole dosage or L-fucose administration resulted in amelioration of an illness observed in antibiotic-treated Muc2-/- mice. Fucose is a monosaccharide presented abundantly in gut glycoproteins, including Mucin2, and is known to be involved in host-microbe interactions, in particular in microbe adhesion. We suppose that further investigation of the role of fucose in protozoan adhesion to host cells may be of great value.

Protozoan infections are under-recognized in Swedish patients with gastrointestinal symptoms.

In acute gastroenteritis (GE), identification of the infectious agent is important for patient management and surveillance. The prevalence of GE caused by protozoa may be underestimated in Swedish patients. The purpose was to compare the prevalence of E. histolytica, Cryptosporidium spp., G. intestinalis, and C. cayetanensis in samples from patients where the clinician had requested testing for gastrointestinal parasites only (n = 758) to where testing for bacterial GE only (n = 803) or where both parasite and bacterial testing (n = 1259) was requested and a healthy control group (n = 197). This prospective cohort study was conducted in Region Jönköping County, Sweden (October 2018-March 2019). Fecal samples were analyzed with microscopy and real-time PCR. Cryptosporidium spp. was detected in 16 patients in the bacterial GE group and in 13 in the both bacterial and parasite group; no cases were detected in the group were only parasite infection was suspected. C. cayetanensis was detected in two patients in the bacterial GE group. One case of E. histolytica was detected in the bacterial group and one in the both bacterial and parasite group. G. intestinalis was detected in 14 patients in the parasite only group, 12 in the both parasite and bacterial group, three in the bacterial GE group, and one in the control group. Diarrhea caused by protozoa, especially Cryptosporidium was under-recognized by clinicians and is likely more common than hitherto estimated in Sweden. A more symptom-based diagnostic algorithm may increase detection and knowledge about protozoan infections.

Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of tissue and blood protozoal infections in the pre- and post-transplant period. Significant new developments in the field have made it necessary to divide the previous single guideline published in 2013 into two sections, with the intestinal parasites separated from this guideline devoted to tissue and blood protozoa. The current update reflects the increased focus on donor screening and risk-based recipient monitoring for parasitic infections. Increased donor testing has led to new recommendations for recipient management of Toxoplasma gondii and Trypanosoma cruzi. Molecular diagnostics have impacted the field, with access to rapid diagnostic testing for malaria and polymerase chain reaction testing for Leishmania. Changes in Babesia treatment regimens in the immunocompromised host are outlined. The risk of donor transmission of free-living amebae infection is reviewed. Changing immigration patterns and the expansion of transplant medicine in developing countries has contributed to the recognition of parasitic infections as an important threat to transplant outcomes. Medications such as benznidazole and miltefosine are now available to US prescribers as access to treatment of tissue and blood protozoa is increasingly prioritized.

Household sanitation is associated with lower risk of bacterial and protozoal enteric infections, but not viral infections and diarrhoea, in a cohort study in a low-income urban neighbourhood in Vellore, India.

OBJECTIVE: This study examined associations between household sanitation and enteric infection - including diarrhoeal-specific outcomes - in children 0-2 years of age in a low-income, dense urban neighbourhood. METHODS: As part of the MAL-ED study, 230 children in a low-income, urban, Indian neighbourhood provided stool specimens at 14-17 scheduled time points and during diarrhoeal episodes in the first 2 years of life that were analysed for bacterial, parasitic (protozoa and helminths) and viral pathogens. From interviews with caregivers in 100 households, the relationship between the presence (and discharge) of household sanitation facilities and any, pathogen-specific, and diarrhoea-specific enteric infection was tested through mixed-effects Poisson regression models. RESULTS: Few study households (33%) reported having toilets, most of which (82%) discharged into open drains. Controlling for season and household socio-economic status, the presence of a household toilet was associated with lower risks of enteric infection (RR: 0.91, 95% CI: 0.79-1.06), bacterial infection (RR: 0.87, 95% CI: 0.75-1.02) and protozoal infection (RR: 0.64, 95% CI: 0.39-1.04), although not statistically significant, but had no association with diarrhoea (RR: 1.00, 95% CI: 0.68-1.45) or viral infections (RR: 1.12, 95% CI: 0.79-1.60). Models also suggested that the relationship between household toilets discharging to drains and enteric infection risk may vary by season. CONCLUSIONS: The presence of a household toilet was associated with lower risk of bacterial and protozoal enteric infections, but not diarrhoea or viral infections, suggesting the health effects of sanitation may be more accurately estimated using outcome measures that account for aetiologic agents.

Outbreaks of Disease Associated with Food Imported into the United States, 1996-20141.

The proportion of US food that is imported is increasing; most seafood and half of fruits are imported. We identified a small but increasing number of foodborne disease outbreaks associated with imported foods, most commonly fish and produce. New outbreak investigation tools and federal regulatory authority are key to maintaining food safety.

Human Intestinal Microbiota: Interaction Between Parasites and the Host Immune Response.

The human gut is a highly complex ecosystem with an extensive microbial community, and the influence of the intestinal microbiota reaches the entire host organism. For example, the microbiome regulates fat storage, stimulates or renews epithelial cells, and influences the development and maturation of the brain and the immune system. Intestinal microbes can protect against infection by pathogenic bacteria, viruses, fungi and parasites. Hence, the maintenance of homeostasis between the gut microbiota and the rest of the body is crucial for health, with dysbiosis affecting disease. This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. Although the mechanisms governing the interaction between intestinal microbiota and protozoa are poorly understood, it is known that the composition of the intestinal bacterial populations modulates the progression of protozoan infection and the outcome of parasitic disease. Most reports on the complex interactions between intestinal bacteria, protozoa and the immune system emphasize the protective role of the microbiota against protozoan infection. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered.

Prevalence and risk factors of intestinal protozoan infections: a population-based study in rural areas of Boyer-Ahmad district, Southwestern Iran.

BACKGROUND: Parasitic infections are still a significant health problem in rural areas in developing countries including Iran. There is no recent population-based data about the prevalence of human intestinal parasites in most rural areas of Iran. The current study aimed to determine the prevalence of intestinal protozoan infection in inhabitants of rural areas of Boyer-Ahmad district, Southwestern Iran. METHODS: A total of 1025 stool samples were collected from the inhabitant of 50 randomly selected villages in Boyer-Ahmad Township. The stool samples were evaluated by parasitological methods including, direct wet-mounting, formalin ethyl acetate concentration, zinc sulfate floatation, and Trichrome permanent stain for detection of protozoan infections. Diarrheic samples were further evaluated with a modified Ziehl-Neelsen staining method for detection of coccidian parasites. RESULTS: The prevalence of both pathogenic and nonpathogenic intestinal parasites in the population was 37.5% (385 out of 1025 cases), some individual with multiple infections. Giardia lamblia was detected in 179 (17.46%), Blastocystis hominis in 182 (17.76%), Entamoeba histolytica/dispar in 9 (0.87%), Endolimax nana in 216 (21.07%), Entamoeba coli in 151 (14.73%), Ioedamoeba butschlii in 45 (4.39%), Chillomastix mesnili in 22 (2.14%), Trichomonas hominis in 2 (0.19%) and Dientamoeba fragillis in 2 (0.19%) of cases. Multivariate logistic regression revealed significant associations between protozoan infection (pathogenic protozoa) and contact with animals (OR yes/no = 2.22, p < 0.001) and educational status (OR higher/illiterate = 0.40, P = 0.01). CONCLUSION: Findings of this study demonstrated that protozoan infection rate in rural areas of southwestern Iran is still high and remained as a challenging health problem in these areas.

Asymptomatic Effluent Protozoa Colonization in Peritoneal Dialysis Patients.

Currently, chronic kidney disease (CKD) is a global health problem. Considering the impaired immunity of CKD patients, the relevance of infection in peritoneal dialysis (PD), and the increased prevalence of parasites in CKD patients, protozoa colonization was evaluated in PD effluent from CKD patients undergoing PD. Overnight PD effluent was obtained from 49 asymptomatic stable PD patients. Protozoa analysis was performed microscopically by searching cysts and trophozoites in direct wet mount of PD effluent and after staining smears. Protozoa were found in PD effluent of 10.2% of evaluated PD patients, namely Blastocystis hominis, in 2 patients, and Entamoeba sp., Giardia sp., and Endolimax nana in the other 3 patients, respectively. None of these patients presented clinical signs or symptoms of peritonitis at the time of protozoa screening. Our results demonstrate that PD effluent may be susceptible to asymptomatic protozoa colonization. The clinical impact of this finding should be further investigated.

The role of water in healthcare-associated infections.

PURPOSE OF REVIEW: The aim is to discuss the epidemiology of infections that arise from contaminated water in healthcare settings, including Legionnaires' disease, other Gram-negative pathogens, nontuberculous mycobacteria, and fungi. RECENT FINDINGS: Legionella can colonize a hospital water system and infect patients despite use of preventive disinfectants. Evidence-based measures are available for secondary prevention. Vulnerable patients can develop healthcare-associated infections with waterborne organisms that are transmitted by colonization of plumbing systems, including sinks and their fixtures. Room humidifiers and decorative fountains have been implicated in serious outbreaks, and pose unwarranted risks in healthcare settings. SUMMARY: Design of hospital plumbing must be purposeful and thoughtful to avoid the features that foster growth and dissemination of Legionella and other pathogens. Exposure of patients who have central venous catheters and other invasive devices to tap water poses a risk for infection with waterborne pathogens. Healthcare facilities must conduct aggressive clinical surveillance for Legionnaires' disease and other waterborne infections in order to detect and remediate an outbreak promptly. Hand hygiene is the most important measure to prevent transmission of other Gram-negative waterborne pathogens in the healthcare setting.

Proteases as regulators of pathogenesis: examples from the Apicomplexa.

The diverse functional roles that proteases play in basic biological processes make them essential for virtually all organisms. Not surprisingly, proteolysis is also a critical process required for many aspects of pathogenesis. In particular, obligate intracellular parasites must precisely coordinate proteolytic events during their highly regulated life cycle inside multiple host cell environments. Advances in chemical, proteomic and genetic tools that can be applied to parasite biology have led to an increased understanding of the complex events centrally regulated by proteases. In this review, we outline recent advances in our knowledge of specific proteolytic enzymes in two medically relevant apicomplexan parasites: Plasmodium falciparum and Toxoplasma gondii. Efforts over the last decade have begun to provide a map of key proteotolyic events that are essential for both parasite survival and propagation inside host cells. These advances in our molecular understanding of proteolytic events involved in parasite pathogenesis provide a foundation for the validation of new networks and enzyme targets that could be exploited for therapeutic purposes. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.

Photodynamic inactivation of microbial pathogens: disinfection of water and prevention of water-borne diseases.

Porphyrins have been shown to act as very efficient photosensitizing agents against a broad number of microbial pathogens, including bacteria, fungi, and protozoa. This property has promising applications at a clinical level for the treatment of infectious diseases by photodynamic therapy. Moreover, this technique is also being used to address environmental problems of high significance, such as the decontamination of wastewaters, the disinfection of fish-farming tanks, the protection of animal species (e.g., amphibians and reptiles) that are endangered by pathogens whose life cycle takes place largely in aqueous media, and the control of populations of noxious insects. Such diversified applications take advantage of the availability of a truly large number of porphyrin derivatives with chemical structures that can be tailored to comply with the physical and chemical properties as well as the biological features of several milieus. In addition, the property typical of porphyrins to absorb essentially all of the wavelengths in the sun emission spectrum allows the promotion of processes largely based on natural resources with significant energy savings and low impact on ecosystems.

Changes in Paramecium caudatum (protozoa) near a switched-on GSM telephone.

The protozoan Paramecium caudatum was examined under normal conditions versus aside a switched-on GSM telephone (900 MHz; 2 Watts). Exposed individuals moved more slowly and more sinuously than usual. Their physiology was affected: they became broader, their cytopharynx appeared broader, their pulse vesicles had difficult in expelling their content outside the cell, their cilia less efficiently moved, and trichocysts became more visible. All these effects might result from some bad functioning or damage of the cellular membrane. The first target of communication electromagnetic waves might thus be the cellular membrane.

Late onset pulmonary Lophomonas blattarum infection in renal transplantation: a report of two cases.

Lophomonas blattarum, a rare protozoa, was involved in pulmonary infections of transplant recipients. We report 2 cases of late onset pulmonary L. blattarum infection in renal transplant recipients with normal graft function and relative normal immune function. The diagnosis in both cases was confirmed by bronchoscopy and broncho alveolar lavage (BAL) fluid examination. Both cases were sensitive to metronidazole treatment, but one case did not completely recover during the follow-up. The diagnosis and treatment were discussed to facilitate improvement in the recognition of this rare infection, especially in transplant recipients.

[Diagnosis of myocarditis]. / Myokarditis-Diagnostik.

The diagnosis of myocarditis is still a major challenge in clinical cardiology due to the variety of infectious and non-infectious disease entities. The present review summarizes from the point of view of cardiopathology and infectious medicine morphological and molecular pathological findings in myocardial biopsies of patients with infectious myocarditis, most commonly induced by viral infections, in addition to non-infectious myocarditis mediated by immune processes. A clinical relevant diagnosis of myocarditis is achieved only by integration of clinical, histological, immunohistological and molecular biological findings.

Biological agents as occupational hazards - selected issues.

There are two main groups of biological agents regarded as occupational hazards: allergenic and/or toxic agents forming bioaerosols, and agents causing zoonoses and other infectious diseases. Bioaerosols occurring in the agricultural work environments comprise: bacteria, fungi, high molecular polymers produced by bacteria (endotoxin) or by fungi (ß-glucans), low molecular secondary metabolites of fungi (mycotoxins, volatile organic compounds) and various particles of plant and animal origin. All these agents could be a cause of allergic and/or immunotoxic occupational diseases of respiratory organ (airways inflammation, rhinitis, toxic pneumonitis, hypersensitivity pneumonitis and asthma), conjunctivitis and dermatitis in exposed workers. Very important among zoonotic agents causing occupational diseases are those causing tick-borne diseases: Lyme borreliosis, anaplasmosis, babesiosis, bartonellosis. Agricultural workers in tropical zones are exposed to mosquito bites causing malaria, the most prevalent vector-borne disease in the world. The group of agents causing other, basically not vector-borne zoonoses, comprises those evoking emerging or re-emerging diseases of global concern, such as: hantaviral diseases, avian and swine influenza, Q fever, leptospiroses, staphylococcal diseases caused by the methicillin-resistant Staphylococcus aureus (MRSA) strains, and diseases caused by parasitic protozoa. Among other infectious, non-zoonotic agents, the greatest hazard for health care workers pose the blood-borne human hepatitis and immunodeficiency viruses (HBV, HCV, HIV). Of interest are also bacteria causing legionellosis in people occupationally exposed to droplet aerosols, mainly from warm water.

Amebíase e epidemiologia / Amebiasis and epidemiology

A infecção por Entamoeba histolytica, identificada há mais de 130 anos por Fedor A. Lesh, existe praticamente em todo o mundo e é hoje considerada uma DST - com relação à transmissão é a doença dos cinco efes: finger, feces, flies, fomites e fornication. A epidemiologia da amebíase na cidade do Rio de Janeiro (Brasil), estudada por um de nós (R.M.), parece confirmar o lugar de infecção no rol das doenças sexualmente transmissíveis. Epidemiologia é o estudo da ocorrência de uma doença - estudos epidemiológicos podem influenciar a vida de populações inteiras. O estudo de Framingham (EUA), a investigação de Sharr sobre a doença dos legionários e o trabalho de John Snow sobre a cólera são exemplos clássicos de estudos epidemiológicos que mudaram o comportamento e estilos de vida.

Entamoeba histolytica infection was identified more than 130 years ago, has worldwide occurrence and nowadays is considered a sexually transmitted disease (STD). Regarding transmission is considered as the five Fs disease: finger, feces, flies, fomites and fornication. Rio de Janeiro city amebiasis epidemiology was studied by one of us and seems to confirm its place on STD list. Epidemiology consists on the study of the disease occurrence - epidemiological studies can influence an entire population life. Framinghan (EUA), Legionnaire's disease Sharr investigation and John Snow cholera study are classic examples of epidemiological studies that changed behaviour and lifestyle.

Transfusion-transmitted infections.

Although the risk of transfusion-transmitted infections today is lower than ever, the supply of safe blood products remains subject to contamination with known and yet to be identified human pathogens. Only continuous improvement and implementation of donor selection, sensitive screening tests and effective inactivation procedures can ensure the elimination, or at least reduction, of the risk of acquiring transfusion transmitted infections. In addition, ongoing education and up-to-date information regarding infectious agents that are potentially transmitted via blood components is necessary to promote the reporting of adverse events, an important component of transfusion transmitted disease surveillance. Thus, the collaboration of all parties involved in transfusion medicine, including national haemovigilance systems, is crucial for protecting a secure blood product supply from known and emerging blood-borne pathogens.

Tritrichomonas foetus: pathogenesis of acute infection in normal, estradiol-treated, and stressed mice.

Environmental stress and endocrine control can affect pathogenesis of sexually transmitted diseases such as trichomoniasis. Acute Tritrichomonas foetus infection was compared in female BALB/c mice to infections in mice treated with high doses of estradiol or housed in constant bright illumination (stressed). In untreated mice, T. foetus readily colonized the reproductive tract, causing minimal epithelial damage and inflammation. Several fold increases of IFN-gamma, TNF-alpha, MCP-1, and IL-6 cytokines were detected after estradiol-treatment of mice, resulting in greatly enhanced inflammation and tissue damage throughout the reproductive tract. Interestingly, estradiol-treatment of mice resulted in reduced T. foetus colonization compared to untreated mice. Infection in stressed mice resulted in increased tissue damage, inflammation, and inflammatory cytokine expression, although parasite colonization within the reproductive tract was similar to that in untreated mice. These results indicate that either estradiol-treatment or stress result in pathogenesis often observed during severe disease. Alternatively, infection in non-treated mice results in chronic colonization, with little inflammation or pathology.