Marcos Lopes

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes.

Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Defense reaction mediated by NMDA mechanisms in the inferior colliculus is modulated by GABAergic nigro-collicular pathways

Electrical stimulation of the inferior colliculus (IC) causes a behavioral activation together with autonomic responses similar to fear reactions to threatening situations. GABAergic mechanisms exert a tonic inhibitory control on the neural substrates of aversion in the IC insofar as local injections of GABA agonists or antagonists inhibit or mimic these defensive behaviors, respectively. Recently, we have shown that systemic injections of the GABA-A receptor agonist muscimol unexpectedly enhanced the freezing and escape responses provoked by gradual increases in the intensity of the electrical stimulation of the IC. Taking into account that the neural circuits mediated by excitatory amino acids (EAA) in the IC may be responsible for the integration of fear states, in the present study we examined whether the defensive behavior induced by local injections of NMDA into the IC is influenced by prior treatment with systemic muscimol and also whether this GABAergic control could be exerted by GABAergic fibers that project to the inferior colliculus from the substantia nigra pars reticulata (SNpr). Rats were implanted with two guide-cannulae aimed at the IC and SNpr through which drug microinfusions with glass micropipette could be made with reduced brain damage. One week after surgery, the animals received either NMDA (7 nmol/0.2 microl) or saline into the IC and were placed into the middle of an enclosure where behavioral responses such as freezing, crossings, jumping, rearing, and turnings could be measured as an indirect index of unconditioned fear. These animals were pretreated either with saline or muscimol (0.5 mg/kg, IP) or with brain injections of saline or muscimol (1 nmol/0.2 ìl into SNpr). NMDA applied into the IC produced a behavioral activation with significant increases in all behavioral measures. IP injections of muscimol or into the SNpr enhanced the defense reaction caused by microinjections of NMDA into the IC. These findings give support to the idea that unconditioned defensive responses generated in the IC may be mediated by NMDA mechanisms. Additionally, a reduction of the inhibitory control exerted by nigrocollicular GABAergic neurons seems to be responsible for the unexpected pro-aversive action of systemic injections of muscimol on the neural substrates of aversion mediated by NMDA in the IC.

Ticks and rickettsiae from wildlife in Belize, Central America

BackgroundThe agents of spotted fevers in Latin America are Rickettsia rickettsii, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and R. massiliae. In Continental Central America, R. rickettsii remains the only known pathogenic tick-borne rickettsia. In the present study, ticks were collected from wild mammals in natural areas of Belize. Besides providing new data of ticks from Belize, we investigated rickettsial infection in some of these ticks. Our results provide ticks harboring rickettsial agents for the first time in Central America.MethodsBetween 2010 and 2015, wild mammals were lived-trapped in the tropical broadleaf moist forests of central and southern Belize. Ticks were collected from the animals and identified to species by morphological and molecular analysis (DNA sequence of the tick mitochondrial 16S RNA gene). Some of the ticks were tested for rickettsial infection by molecular methods (DNA sequences of the rickettsial gltA and ompA genes).ResultsA total of 84 ticks were collected from 8 individual hosts, as follows: Amblyomma pacae from 3 Cuniculus paca; Amblyomma ovale and Amblyomma coelebs from a Nasua narica; A. ovale from an Eira Barbara; A. ovale, Amblyomma cf. oblongoguttatum, and Ixodes affinis from a Puma concolor; and A. ovale, A. coelebs, A. cf. oblongoguttatum, and I. affinis from two Panthera onca. Three rickettsial agents were detected: Rickettsia amblyommii in A. pacae, Rickettsia sp. strain Atlantic rainforest in A. ovale, and Rickettsia sp. endosymbiont in Ixodes affinis.ConclusionsThe present study provides unprecedented records of ticks harboring rickettsial agents in the New World. An emerging rickettsial pathogen of South America, Rickettsia sp. strain Atlantic rainforest, is reported for the first time in Central America. Besides expanding the distribution of 3 rickettsial agents in Central America, our results highlight the possible occurrence of Rickettsia sp. strain Atlantic rainforest-caused spotted fever human cases in Belize, since its possible vector, A. ovale, is recognized as one of the most important human-biting ticks in the Neotropical region.

Presence of antibodies against Toxoplasma gondii, Neospora caninum and Leishmania infantum in dogs from Piauí.

This study aimed to evaluate the presence of antibodies against Neospora caninum, Toxoplasma gondii and Leishmania infantum in dogs attended at the Veterinary Hospital of the Federal University of Piauí, Northeastern Brazil, where there are no reports of the occurrence of N. caninum and T. gondii in dogs. Serum samples from 530 dogs of genders, different ages and breeds from the municipality of Teresina and nearby towns were analyzed using three indirect fluorescent antibody tests, each one targeting one of the three agents. The associations between the parasites and gender, breed and age of the dogs were assessed by the chi-square test (p > 0.05). The occurrence of antibodies to N. caninum, T. gondii and L. infantum was 3.2, 18.0 and 78.1%, respectively. Toxoplasma gondii was more frequently found in older dogs (p < 0.05) whereas L. infantum was more common in animals aged between 1 to 3 years (p < 0.05). In order to evaluate potential associations between the presence of anti-N. caninum and anti-T. gondii antibodies and Leishmania infection, 240 dogs were selected (120 positive and 120 negative for Leishmania spp.), based on serological and parasitological diagnoses. No association was found between Leishmania spp. and the coccidian parasites (p > 0.05). The results confirm the exposure of dogs to these parasites in the State of Piauí.

Health-related quality of life of children and adolescents with CKD stages 4–5 and their caregivers

BackgroundRenal replacement therapies may affect the quality of life of patients and their primary caregivers (PC).MethodsThis study describes the perception of health-related quality of life (HRQoL) of children/adolescents with CKD stages 4–5, as well as of their PC (n = 64), in comparison to healthy peers and their PC (n = 129), respectively, based on the Peds QL™ 4.0 and Short Form-36 (SF-36) questionnaires and selected biomarkers.ResultsPatients reported a deleterious impact on physical capacity and on social and school activities. A negative influence on emotional aspects was reported by older patients, but not by their PC. Hemodialysis, followed by peritoneal dialysis, had a more negative impact on patients’ physical functioning domain. PC HRQol proxy reports differed from those of their children, especially in older patients. PC of both groups presented similar SF-36 scores. An association was demonstrated between the magnitude of treatment target inadequacies, lower specific dominion scores in the patients/PC proxy reports and PC SF-36 general health scores.ConclusionThe HRQoL of patients with CKD stages 4–5 is negatively affected to different degrees depending on age and treatment modality. The results suggest an association between worsening HRQoL parameters and inadequate control of recognized therapeutic CKD treatment targets.

Occurrence of antibodies against Toxoplasma gondii and its isolation and genotyping in donkeys, mules, and horses in Brazil.

The occurrence of antibodies against Toxoplasma gondii was determined in donkeys, mules, and horses from different regions of Brazil. Serum samples from 304 donkeys (67.11%), 118 horses (26.05%), and 31 mules (6.84%) were analyzed by means of the indirect fluorescent antibody test (cutoff=64). Antibodies against T. gondii were detected in 129 equids (28.47%) (82 donkeys, 32 horses, and 15 mules). Tissue samples from 19 seropositive and 50 seronegative animals were obtained in order to isolate the parasite by means of mouse bioassay, and T. gondii was isolated from a donkey. Through genotypic characterization of the isolate, by means of polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) using 11 genotypic markers, the genotype #163 (TgCkBr220), which has already been described in chickens in Brazil, was identified.

A new species of Ornithodoros (Acari: Argasidae) from desert areas of northern Chile

Ornithodoros atacamensis n. sp. is described from larvae collected on the lizard Liolaemus bisignatus and from free-living adults collected in desert areas from the Pan de Azúcar and Llanos de Challe National Parks, in Northern Chile. Additionally, unengorged larvae were obtained from fertilized females, which laid eggs in the laboratory. Morphological and mitochondrial 16S rDNA sequence analyses were performed in order to compare this new soft tick species with other congeneric Neotropical representatives. Larvae of O. atacamensis are morphologically closely related to Ornithodoros talaje sensu stricto, Ornithodoros puertoricensis, Ornithodoros rioplatensis, Ornithodoros guaporensis and Ornithodoros hasei, all belonging to the O. talaje species group. The larval diagnostic characters for this species are a combination of a large pyriform dorsal plate with a length of approximately 300μm, 17 pairs of dorsal setae with five central pairs, hypostome with apex pointed and dental formula 2/2 in most rows, 3/3 apically, and capsule of the Hallers organ oval in shape without reticulations. Phylogenetic analyses inferred from the mitochondrial 16S rRNA gene and a Principal Component Analysis based on morphometric characters provide additional support to the description of O. atacamensis as an independent lineage within the genus clustering within the O. talaje species group.

Toxoplasma gondii in domestic and wild animals from forest fragments of the municipality of Natal, northeastern Brazil.

Toxoplasmosis stands out as a global disease that has felines as definitive hosts. In the municipality of Natal, Rio Grande do Norte State, Brazil, two parks are notable for their ecological and social importance. This study aimed to investigate the presence of Toxoplasma gondii in short hair cats, bats and small non-volant mammals in these two ecological reserves. Altogether, biological samples were obtained from 154 mammals, 92 wild animals from both areas and 62 domestic cats of the Parque da Cidade. In total, 22 (53.7%) non-volant wild mammals, 11 (21.5%) bats and 28 (52.8%) cats were positive for IgG anti-T. gondii antibodies using the Modified Agglutination Test (≥ 25). It was possible to detect the presence of T. gondii DNA, by means of a molecular amplification of a B1 gene fragment (155bp), in 92 tissue samples from wild animals, including Didelphis albiventris, Monodelphis domestica, Artibeus lituratus, Carollia perspicillata and Glossophaga soricina. Of the 62 cats examined by the same molecular method, T. gondii DNA could be detected in 4 cats. In this study, it was observed the circulation of T. gondii in wild species and domestic cats, demonstrating the involvement of wild and domestic animals in the cycle of T. gondii.

Semantic Verbal Fluency test in dementia: Preliminary retrospective analysis

The Semantic Verbal Fluency (SVF) test entails the generation of words from a given category within a pre-set time of 60 seconds. Objectives To verify whether socio-demographic and clinical data of individuals with dementia correlate with the performance on the SVF test and to ascertain whether differences among the criteria of number of answers, clusters and data spread over the intervals, predict clinical results. Methods This was a retrospective study of 49 charts of demented patients classified according to the Clinical Dementia Rating (CDR) scale. We correlated education, age and gender, as well as CDR and Mini-Mental State Exam (MMSE) scores with the number of answers, clustering and switching distributed over four 15-second intervals on the SVF test. Results The correlation between number of answers and quartiles was weak (r=0.407, p=0.004; r=0.484, p< 0.001) but correlation between the number of clusters and responses was strong (r=0.883, p< 0.001). The number of items on the SVF was statistically significant with MMSE score (p=0.01) and there was a tendency for significance on the CDR (p=0.06). The results indicated little activity regarding what we propose to call cluster recalling in the two groups. Discussion The SVF test, using number of items generated, was found to be more effective than classic screening tests in terms of speed and ease of application in patients with CDR 2 and 3.

Prevalence of antibodies against Neospora spp. and Sarcocystis neurona in donkeys from northeastern Brazil.

Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT results for S. neurona showed a poor concordance (value of Kappa=0.051). This is the first report of Neospora spp. antibodies in Brazilian donkeys and the first detection of antibodies against S. neurona in this animal species.