Retrospective study of the occurrence of Cyclospora cayetanensis at Clinical Hospital of the University of São Paulo Medical School, SP

Cyclospora cayetanensis causes watery diarrhea in tropical countries, among travelers and after ingestion of contaminated water and food. Very little is known about its epidemiology, pathogenic aspects and reservoirs. In Brazil, its prevalence is unknown and to date there have been reports of three outbreaks. We report here a retrospective study of 5,015 stool samples from 4,869 patients attended at Clinical Hospital of the University of São Paulo Medical School, SP, Brazil between April 1996 and January 2002, with 14 cases of Cyclospora cayetanensis being detected there was a prevalence of 0.3%. Of the 14 infected patients, the mean age was 38 years and 71.4% were female. Ten patients presented symptoms; six presented levels of immunological markers and five patients were immunodeficient.

Factors associated with Leptospira sp infection in a large urban center in northeastern Brazil

Leptospirosis is a zoonotic disease that has emerged to cause epidemics in urban communities in developing countries. However, little is known about the infection in the general population. A seroprevalence survey was performed on a random sample of 1,390 subjects in Salvador, Brazil. Data on environmental and socioeconomic factors were collected. The microagglutination test of serum samples was used to show any prior Leptospira infection. The overall seroprevalence was 12.4%. Among the seropositive individuals, 111 (61%) had high titers for serovars of the Icterohaemorrhagiae serogroup. Seroprevalence increased with age and was similar for males and females. A positive correlation between Leptospira infection and low educational level was found. These findings indicate that a significant proportion of this urban population is exposed to pathogenic Leptospira. Public health actions for leptospirosis control will need to target not only the traditional groups at risk of infection with severe forms of this disease, but also the general population that is at risk.

Is severe visceral leishmaniasis a systemic inflammatory response syndrome? A case control study

INTRODUCTION: The objective of the study is to identify the main risk factors for death by New World visceral leishmaniasis and establish a coherent pathogenic substrate of severe disease based on clinical findings. METHODS: Seventy-six deceased inpatients and 320 successfully treated inpatients with VL were studied in a case control study. RESULTS: Bacterial infection and bleeding were mutually exclusive events leading to death. Five risk factors were unique for death by bacterial infection (malnutrition, pulmonary rales, severe anemia, severe absolute neutropenia and higher neutrophil count), while another six were unique for death by bleeding (jaundice, severe relative neutropenia, severe thrombocytopenia, liver injury, kidney failure, higher bone marrow parasite load). Bacterial infection, bleeding, severe anemia, diarrhea, dyspnea, edema, jaundice and bone marrow parasite load were the main syndromes of visceral leishmaniasis among successfully treated patients. CONCLUSIONS: The data support the idea that bacterial infections are due to immune paralysis. Broad organ and system involvement is plausibly due to the high production of proinflammatory cytokines, whose actions fit well with visceral leishmaniasis. The syndromes and causative mediators are typical of a slowly developing systemic inflammatory response syndrome.

Long-term outcome of neuroparacoccidioidomycosis treatment

INTRODUCTION: Neuroparacoccidioidomycosis (NPCM) is a term used to describe the invasion of the central nervous system by the pathogenic fungus Paracoccidioides brasiliensis. NPCM has been described sporadically in some case reports and small case series, with little or no focus on treatment outcome and long-term follow-up. METHODS: All patients with NPCM from January 1991 to December 2006 were analyzed and were followed until December 2009. RESULTS: Fourteen (3.8%) cases of NPCM were identified out of 367 patients with paracoccidioidomycosis (PCM). A combination of oral fluconazole and sulfamethoxazole/trimethoprim (SMZ/TMP) was the regimen of choice, with no documented death due to Paracoccidioides brasiliensis infection. Residual neurological deficits were observed in 8 patients. Residual calcification was a common finding in neuroimaging follow-up. CONCLUSIONS: All the patients in this study responded positively to the association of oral fluconazole and sulfamethoxazole/trimethoprim, a regimen that should be considered a treatment option in cases of NPCM. Neurological sequela was a relatively common finding. For proper management of these patients, anticonvulsant treatment and physical therapy support were also needed.

Seroepidemiological monitoring in sentinel animals and vectors as part of arbovirus surveillance in the state of Mato Grosso do Sul, Brazil

INTRODUCTION: From February-September 2010, seroepidemiological surveys were conducted on non-human primates and transmitter vector capture was used to investigate the possible circulation of arboviruses in the municipalities of Bonito, Campo Grande, and Jardim, State of Mato Grosso do Sul, Brazil. METHODS: A total of 65 primates from the wild and captivity were used, and potential vectors were captured using Castro and dip nets. Serum samples were tested at the Instituto Evandro Chagas, State of Pará, using the hemagglutination inhibition test to detect total antibodies against 19 different arboviruses. Virus isolation was attempted from serum samples and arthropod suspensions using newborn mice and the C6/36 cell line clone. In addition, identification of the vector species was conducted. RESULTS: From the 19 serum samples from Campo Grande, 1 sample had a 1:20 titer for Flavivirus. From the 35 samples collected in Bonito, 17 samples had antibodies to arboviruses, 4 (11.4%) were positive for Alphavirus, and 5 (14.2%) were positive for Flavivirus. Monotypic reactions were observed for the Mayaro (n = 10) and Oropouche (n = 5) viruses, and 6 (17.1%) samples had titers for >1 virus. We captured 120 Culicidae individuals that were potential arbovirus transmitters in Jardim; however, all the samples were negative for the viruses. CONCLUSIONS: Mato Grosso do Sul has a variety of vertebrate hosts and transmission vectors, thereby providing ideal conditions for the emergence or reemergence of arboviruses, including some pathogenic to human beings.

cagE as a biomarker of the pathogenicity of Helicobacter pylori

IntroductionHelicobacter pylori infection is associated with gastro-duodenal diseases. Genes related to pathogenicity have been described for H. pylori and some of them appear to be associated with more severe clinical outcomes of the infection. The present study investigates the role of cagE as a pathogenicity biomarker of H. pylori compare it to cagA, vacA, iceA and babA2 genes and correlate with endoscopic diagnoses.MethodsWere collected biopsy samples of 144 dyspeptic patients at the Hospital of the Federal University of Rio Grande, Rio Grande do Sul, Brazil. After collection, the samples were sent for histological examination, DNA extraction and detection of all putative pathogenicity genes by PCR.ResultsOf the 144 patients undergoing endoscopy, 57 (39.6%) presented H. pylori by histological examination and PCR by detection of the ureA gene. Based on the endoscopic diagnoses, 45.6% (26/57) of the patients had erosive gastritis, while 54.4% (31/57) had enanthematous gastritis. The genes cagA, cagE, vacAs1/m1, vacAs1/m2 and iceA1 were related to erosive gastritis, while the genes vacAs2/m2, iceA2 and babA2 were associated to enanthematous gastritis. We found a statistically significant association between the presence of cagE and the endoscopic diagnosis. However, we detect no statistically significant association between the endoscopic diagnosis and the presence of cagA, vacA, iceA and babA2, although a biological association has been suggested.ConclusionsThus, cagE could be a risk biomarker for gastric lesions and may contribute to a better evaluation of the H. pylori pathogenic potential and to the prognosis of infection evolution in the gastric mucosa.

Development of duplex-PCR for identification of Aeromonas species

Introduction The number of reports of intestinal infections caused by Aeromonas spp. has increased significantly in recent years. In most clinical laboratories, identification of these bacteria is carried out by general phenotypic tests that sometimes do not accurately differentiate Aeromonas and Vibrio. Methods A duplex-polymerase chain reaction (PCR) was developed directed to 2 targets identifying Aeromonas spp. pathogenic to humans. Results The duplex-PCR results were reproducible and specific for Aeromonas spp. pathogenic to humans. Conclusions This method will allow differentiation between Vibrio and Aeromonas spp. in patients with in cholera-like symptoms and can also be used in water quality monitoring.

Ants in a hospital environment and their potential as mechanical bacterial vectors

Introduction We studied the richness and abundance of ant species, their bacteria and the bacteria isolated from patient clinical samples. Methods Ants were collected with baited traps at 64 sites in a public hospital in São Luis, State of Maranhão, Brazil. Results In total, 1,659 ants from 14 species were captured. The most frequent species were Crematogaster victima, Solenopsis saevissima, Tapinoma melanocephalum, Camponotus vittatus and Paratrechina fulva. Forty-one species of bacteria were isolated from the ants and 18 from patients. Conclusions Ants are potential vehicles for pathogenic and opportunistic bacteria, and they can represent a risk factor in nosocomial infections.

Environmental isolation, biochemical identification, and antifungal drug susceptibility of Cryptococcus species

Introduction The incidence of opportunistic fungal infections has increased in recent years and is considered an important public health problem. Among systemic and opportunistic mycoses, cryptococcosis is distinguished by its clinical importance due to the increased risk of infection in individuals infected by human immunodeficiency virus. Methods To determine the occurrence of pathogenic Cryptococcus in pigeon excrement in the City of Araraquara, samples were collected from nine environments, including state and municipal schools, abandoned buildings, parks, and a hospital. The isolates were identified using classical tests, and susceptibility testing for the antifungal drugs (fluconazole, itraconazole, voriconazole, and amphotericin B) independently was also performed. After collection, the excrement samples were plated on Niger agar and incubated at room temperature. Results A total of 87 bird dropping samples were collected, and 66.6% were positive for the genus Cryptococcus. The following species were identified: Cryptococcus neoformans (17.2%), Cryptococcus gattii (5.2%), Cryptococcus ater (3.5%), Cryptococcus laurentti (1.7%), and Cryptococcus luteolus (1.7%). A total of 70.7% of the isolates were not identified to the species level and are referred to as Cryptococcus spp. throughout the manuscript. Conclusions Although none of the isolates demonstrated resistance to antifungal drugs, the identification of infested areas, the proper control of birds, and the disinfection of these environments are essential for the epidemiological control of cryptococcosis.

Interaction of an opportunistic fungus Purpureocillium lilacinum with human macrophages and dendritic cells

IntroductionPurpureocillium lilacinum is emerging as a causal agent of hyalohyphomycosis that is refractory to antifungal drugs; however, the pathogenic mechanisms underlying P. lilacinum infection are not understood. In this study, we investigated the interaction of P. lilacinum conidia with human macrophages and dendritic cells in vitro.MethodsSpores of a P. lilacinum clinical isolate were obtained by chill-heat shock. Mononuclear cells were isolated from eight healthy individuals. Monocytes were separated by cold aggregation and differentiated into macrophages by incubation for 7 to 10 days at 37°C or into dendritic cells by the addition of the cytokines human granulocyte-macrophage colony stimulating factor and interleukin-4. Conidial suspension was added to the human cells at 1:1, 2:1, and 5:1 (conidia:cells) ratios for 1h, 6h, and 24h, and the infection was evaluated by Giemsa staining and light microscopy.ResultsAfter 1h interaction, P. lilacinum conidia were internalized by human cells and after 6h contact, some conidia became inflated. After 24h interaction, the conidia produced germ tubes and hyphae, leading to the disruption of macrophage and dendritic cell membranes. The infection rate analyzed after 6h incubation of P. lilacinumconidia with cells at 2:1 and 1:1 ratios was 76.5% and 25.5%, respectively, for macrophages and 54.3% and 19.5%, respectively, for cultured dendritic cells.ConclusionsP. lilacinum conidia are capable of infecting and destroying both macrophages and dendritic cells, clearly demonstrating the ability of this pathogenic fungus to invade human phagocytic cells.

Potential for entomopathogenic fungi to control Triatoma dimidiata (Hemiptera: Reduviidae), a vector of Chagas disease in Mexico

Introduction The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Methods Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50) was then calculated for the most pathogenic isolate. Results Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05) and differed from that in triatomine nymphs (p=0.009). The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Conclusions Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.

Detection of intestinal parasites on field-grown strawberries in the Federal District of Brazil

Introduction This study evaluated the presence of pathogenic human parasites on field-grown strawberries in the Federal District of Brazil. Methods A total of 48 samples of strawberries and 48 soil samples from 16 properties were analyzed. Results Contaminated strawberries were detected in 56% of the properties. Schistosoma mansoni, Ascaris lumbricoides or Ascaris suum, Balantidium coli, Endolimax nana, and Entamoeba spp. were detected. Soil was contaminated with Entamoeba spp., Entamoeba coli, Strongyloides spp., Ancylostomatidae, and Hymenolepis nana. Conclusions Producers should be instructed on the safe handling of strawberries in order to reduce the incidence of strawberries that are contaminated with enteroparasites.

Leptospirosis in animals and human contacts in Egypt: broad range surveillance

INTRODUCTION: Leptospirosis is a re-emerging zoonotic disease of humans and animals worldwide. The disease is caused by pathogenic species of the genus Leptospira. These organisms are maintained in nature via chronic renal infection of carrier animals, which excrete the organisms in their urine. Humans become infected through direct or indirect exposure to infected animals and their urine or through contact with contaminated water and soil. This study was conducted to investigate Leptospira infections as a re-emerging zoonosis that has been neglected in Egypt. METHODS: Samples from 1,250 animals (270 rats, 168 dogs, 625 cows, 26 buffaloes, 99 sheep, 14 horses, 26 donkeys and 22 camels), 175 human contacts and 45 water sources were collected from different governorates in Egypt. The samples were collected from different body sites and prepared for culture, PCR and the microscopic agglutination test (MAT). RESULTS: The isolation rates of Leptospira serovars were 6.9%, 11.3% and 1.1% for rats, dogs and cows, respectively, whereas the PCR results revealed respective detection rates of 24%, 11.3% and 1.1% for rats, dogs and cows. Neither the other examined animal species nor humans yielded positive results via these two techniques. Only six Leptospira serovars (Icterohaemorrhagiae, Pomona, Canicola, Grippotyphosa, Celledoni and Pyrogenes) could be isolated from rats, dogs and cows. Moreover, the seroprevalence of leptospiral antibodies among the examined humans determined using MAT was 49.7%. CONCLUSIONS: The obtained results revealed that rats, dogs and cows were the most important animal reservoirs for leptospirosis in Egypt, and the high seroprevalence among human contacts highlights the public health implications of this neglected zoonosis.

Preliminary screening of the larvicidal effect of Brevibacillus laterosporus strains against the blowfly Chrysomya megacephala(Fabricius, 1794) (Diptera: Calliphoridae)

AbstractINTRODUCTION: This study evaluated whether different strains of Brevibacillus laterosporus could be used to control larvae of the blowfly Chrysomya megacephala , a pest that affects both human and animal health.METHODS:Mortality rates were recorded after 1-mL suspensions of sporulated cells of 14 different strains of B. laterosporus were added to 2.5g of premixed diet consisting of rotting ground beef fed to first instar larvae of C. megacephala . All bioassays were performed using 10 larvae per strain, with a minimum of three replicates for each bioassay. Larval mortality was recorded daily up to seven days.RESULTS:Strains Bon 707, IGM 16-92, and Shi 3 showed the highest toxicity toward the larvae producing 70.5%, 64.5%, and 51.6% of larval mortality, respectively, which was significantly higher than that in the control group (p < 0.05). In contrast, strains NRS 1642, NRS 661, NRS 590 BL 856, NRS 342, ATCC 6457, Bon 712, and NRS 1247 showed limited or no pathogenic activity against the target larvae.CONCLUSIONS:Our preliminary data indicated that B. laterosporus could be used to develop bioinsecticides against C. megacephala .

Frequency of histopathological changes in Howler monkeys ( Alouatta sp.) naturally infected with yellow fever virus in Brazil

Abstract: INTRODUCTION: Due to the importance that Howler monkeys have on the yellow fever (YF) epidemiological sylvatic cycle in Brazil, more accurate morphological diagnostic criteria needs to be established, especially considering the differences that may exist between the genera of Brazilian non-human primates (NHPs) involved in yellow fever virus (YFV) epizootics. METHODS: Records of YF epizootics in NHPs in Brazil between 2007 and 2009 were obtained from the Brazilian Ministry of Health database to select YF positive (n=98) Howler monkeys (Alouatta sp.) for this study. The changes described in the histopathological reports were categorized by organ and their frequencies calculated. RESULTS: The most frequent lesions observed in the animals with YF were hepatocyte apoptosis (Councilman body formation), midzonal hepatocyte necrosis, steatosis, liver hemorrhage, inflammatory mononuclear cell infiltration of the liver, renal acute tubular necrosis and interstitial nephritis. Midzonal hepatocyte necrosis, steatosis and hemorrhage presented positive correlations with apoptosis of hepatocytes, suggesting strong YFV pathogenic effect association; they were also the main histopathological changes in the Alouatta sp. A pronounced negative correlation between apoptosis of hepatocytes and hepatic mononuclear cell infiltration pointed to significant histopathological differences between YFV infection in Howler monkeys and humans. CONCLUSIONS: The results warn that NHPs may exhibit different response patterns following YFV infection and require a more careful diagnosis. Presumptive diagnosis based on primate histopathological lesions may contribute to public health service control.