Interrelationship between Ectoparasites and Wild Rodents from Tijucas do Sul, State of Paraná, Brazil

Sixteen species of ectoparasites were collected from 50 wild rodents, from August 1990 to August 1991, in an area of Araucaria augustifolia forest, in the municipality of Tijucas do Sul, State of Paraná, Brazil. Ectoparasites infested 98% of the rodents, with the highest indices of infestation found in the dry-cool season. Species that occurred in single or multiple infestations were recorded. Ectoparasite/host associations were significant (p<0.01) for Gigantolaelaps wolffsohni/Oryzomys nigripes, Polygenis pradoi/Oxymycterus sp. and Amblyopinus sp./Oxymycterus sp. The following represent new host records: Polygenis (Polygenis) tripus from Akodon serrensis and Hoplopleura sciuricola from Sciurus aestuans. New geographic records are given for two species of flea and one sucking lice.

Cotton Rats (Sigmodon hispidus) and Black Rats (Rattus rattus) as Possible Reservoirs of Leishmania spp. in Lara State, Venezuela

A total of 519 wild animals belonging to eleven species were collected during a two year study in a cutaneous leishmaniasis endemic area in Venezuela (La Matica, Lara State). The animals were captured in home-made Tomahawk-like traps baited with maize, bananas or other available local fruits, and parasites were isolated from 27 specimens. Two different species were found naturally infected with flagellates, i.e., cotton rats (Sigmodon hispidus) and black rats (Rattus rattus). Characterization of the parasites using PCR, kDNA restriction pattern and hybridization with species-specific probes revealed the presence of Leishmania (L.) mexicana in three of the black rats and Leishmania (V.) braziliensis in two others. The latter species was also identified in the single positive specimen of S. hispidus. The results suggested both species of animals as possible reservoirs of Leishmania sp.

Observations on Eimeria species of Dasyprocta leporina (Linnaeus, 1758)(Rodentia: Dasyproctidae) from the state of Pará, North Brazil

Redescriptions are given of the mature oocysts of Eimeria aguti Carini 1935, E. cotiae Carini, 1935 and E. paraensis Carini, 1935, in the faeces of five specimens of the rodent Dasyprocta leporina (Rodentia: Dasyproctidae) from the state of Pará, North Brazil. New information is provided on the sporulation time of these parasites and the prepatent period in experimentally infected D. leporina. Some endogenous stages of E. cotiae are described in the epithelial cells of the ileum, and the absence of any oocysts in the gall-bladder contents of the infected animals indicates that the intestine is also the site of development of E. aguti and E. paraensis. Difficulties in separating E. cotiae and E. paraensis on morphology of the oocysts are discussed. The oocysts of both parasites share many structural features and have a wide size range. It is concluded that although it is at present best to maintain these names, the possibility exists that they were separately given to oocysts of smaller dimensions (E. cotiae) and larger dimensions (E. paraensis) of a single parasite. Location of an endogenous site of development for E. paraensis that is distinctly separate from that of E. cotiae might establish more definitely the separate specific status of the two parasites.

Genotyping of Mycobacterium tuberculosis isolates from alow-endemic setting in northwestern state of Paraná in Southern Brazil

The purpose of this study was to provide information about the genetic diversity and prevalent genotype of Mycobacterium tuberculosis in a low-endemic setting in northwestern state of Paraná in Southern Brazil. We employed spoligotyping and mycobacterial interspersed repetitive units-variable number tandem repeat (MIRU-VNTR) techniques to genotype M. tuberculosisisolates from patients with pulmonary tuberculosis (TB). The 93 isolates analyzed by spoligotyping were divided into 36 different patterns, 30 of which were described in the SITVIT database. Latin American and Mediterranean, Haarlem and T families were responsible for 26.9%, 17.2% and 11.8% of TB cases, respectively. From the 84 isolates analyzed by MIRU-VNTR, 58 shared a unique pattern and the remaining 26 belonged to nine clusters. The MIRU loci 40, 23, 10 and 16 were the most discriminatory. A combination of MIRU-VNTR and spoligotyping resulted in 85.7% discriminatory power (Hunter-Gaston index = 0.995). Thus, combining spoligotyping and MIRU-VNTR typing proved to be most useful for epidemiological study in this low-endemic setting in Southern Brazil. The current study demonstrated that there is significant diversity in circulating strains in the city of Maringá and the surrounding regions, with no single genotype of M. tuberculosispredominating.

Mayaro virus and dengue virus 1 and 4 natural infection in culicids from Cuiabá, state of Mato Grosso, Brazil

This study aimed to verify the diversity of Culicidae species and their frequency of infection with flaviviruses and alphaviruses in Cuiabá, state of Mato Grosso, Brazil. Mosquitoes were captured with Nasci aspirators and hand net in 200 census tracts, identified alive at species level and pooled in one-20 (11,090 mosquitoes, 14 species). Female pools (n = 610) were subjected to multiplex seminested-reverse transcription-polymerase chain reaction (RT-PCR) for 11 flavivirus and five alphavirus. Positive pools were tested by single RT-PCR followed by nucleotide sequencing, by RT-PCR for E1 gene [Mayaro virus (MAYV)] and by inoculation in Vero cells (MAYV) or C6/36 cells (flaviviruses). One/171 Aedes aegypti was positive for dengue virus (DENV)-1, 12/403 Culex quinquefasciatus, and four/171Ae. aegypti for MAYV, which was isolated from two pools containing two nonengorged females of Ae. aegypti and two ofCx. quinquefasciatus. DENV-4 was detected in 58/171 pools of Ae. aegytpi, 105/403 Cx. quinquefasciatus, two/five Psorophora sp., two/11 Psorophora varipes/Psorophora albigenu, one/one Sabethes chloropterus, two/five Culex bidens/Culex interfor, and one/one Aedes sp. DENV-4 was isolated from two pools containing three and 16 nonengorged Cx. quinquefasciatus females. Phylogenetic analysis revealed MAYV belongs to genotype L, clustering with human samples of the virus previously identified in the city. Cuiabá has biodiversity and ecosystem favourable for vector proliferation, representing a risk for arbovirus outbreaks.

Lauromacromia bedei sp. nov. from the State of Minas Gerais, Brazil (Odonata, Corduliidae)

Lauromacromia bedei is described and illustrated from a single male specimen collected in a river at the "cerrado" region of the State of Minas Gerais, Brazil.

Preliminary evaluation of acid mine drainage in Minas Gerais State, Brazil

Mining in the State of Minas Gerais-Brazil is one of the activities with the strongest impact on the environment, in spite of its economical importance. Amongst mining activities, acid drainage poses a serious environmental problem due to its widespread practice in gold-extracting areas. It originates from metal-sulfide oxidation, which causes water acidification, increasing the risk of toxic element mobilization and water resource pollution. This research aimed to evaluate the acid drainage problem in Minas Gerais State. The study began with a bibliographic survey at FEAM (Environment Foundation of Minas Gerais State) to identify mining sites where sulfides occur. Substrate samples were collected from these sites to determine AP (acidity potential) and NP (neutralization potential). The AP was evaluated by the procedure of the total sulfide content and by oxygen peroxide oxidation, followed by acidity titration. The NP was evaluated by the calcium carbonate equivalent. Petrographic thin sections were also mounted and described with a special view to sulfides and carbonates. Based on the chemical analysis, the acid-base accounting (ABA) was determined by the difference of AP and NP, and the acid drainage potential obtained by the ABA value and the total volume of material at each site. Results allowed the identification of substrates with potential to generate acid drainage in Minas Gerais state. Altogether these activities represent a potential to produce between 3.1 to 10.4 billions of m³ of water at pH 2 or 31.4 to 103.7 billions of m³ of water at pH 3. This, in turn, would imply in costs of US$ 7.8 to 25.9 millions to neutralize the acidity with commercial limestone. These figures are probably underestimated because some mines were not surveyed, whereas, in other cases, surface samples may not represent reality. A more reliable state-wide evaluation of the acid drainage potential would require further studies, including a larger number of samples. Such investigations should consider other mining operations beyond the scope of this study as well as the kinetics of the acid generation by simulated weathering procedures.

Ammonia volatilization in no-till system in the south-central region of the State of Paraná, Brazil

Ammonia (NH3) volatilization can reduce the efficiency of urea applied to the surface of no-till (NT) soils. Thus, the objectives of this study were to evaluate the magnitude of NH3 losses from surface-applied urea and to determine if this loss justifies the urea incorporation in soil or its substitution for other N sources under the subtropical climatic conditions of South-Central region of Paraná State, Brazil. The experiment, performed over four harvesting seasons in a clayey Hapludox followed a randomized block design with four replicates. A single dose of N (150 kg ha-1) to V5 growth stage of corn cultivated under NT system was applied and seven treatments were evaluated, including surface-applied urea, ammonium sulfate, ammonium nitrate, urea with urease inhibitor, controlled-release N source, a liquid N source, incorporated urea, and a control treatment with no N application. Ammonia volatilization was evaluated for 20 days after N application using a semi-open static system. The average cumulative NH3 loss due to the superficial application of urea was low (12.5 % of the applied N) compared to the losses observed in warmer regions of Southeastern Brazil (greater than 50 %). The greatest NH3 losses were observed in dry years (up to 25.4 % of the applied N), and losses decreased exponentially as the amount of rainfall after N application increased. Incorporated urea and alternative N sources, with the exception of controlled-release N source, decreased NH3 volatilization in comparison with surface-applied urea. Urea incorporation is advantageous for the reduction of NH3 volatilization; however, other aspects as its low operating efficiency should be considered before this practice is adopted. In the South-Central region of Paraná, the low NH3 losses from the surface-applied urea in NT system due to wet springs and mild temperatures do not justify its replacement for other N sources.

State of the science and the way forward for the ecotoxicological assessment of contaminated land

Over the past two decades, soil ecotoxicologists have made strides in utilizing the basic concepts and advancements in soil zoology and ecology. They have applied the existing tools, and developed new ones to investigate how chemical contamination can affect soil ecosystems, including the degradation or destruction of soil quality and habitats or the diminishment of belowground biodiversity. Soil ecotoxicologists are applying a suite of standard protocols, originally developed as laboratory tests with single chemicals (e.g., pesticides), and further enhancing both the approaches and protocols for the assessment of contaminated lands. However, ecological relevance of some approaches remains unresolved. The authors discuss the main challenges for a coherent ecotoxicological assessment of soil ecosystems amid contaminated lands, and provide recommendations on how to integrate the effects of physical and chemical soil properties, the variations in the diversity of soil invertebrates, and the interactions among organisms of various trophic levels. The review examines new international approaches and test methods using examples from three continents (in particular research conducted in Brazil), and provides recommendations for improving ecological relevance of ecotoxicological investigations of contaminated lands.

Plasmid DNA damage induced by singlet molecular oxygen released from the naphthalene endoperoxide DHPNO2 and photoactivated methylene blue

To investigate oxidative lesions and strand breaks induction by singlet molecular oxygen (¹O2), supercoiled-DNA plasmid was treated with thermo-dissociated DHPNO2 and photoactivated-methylene blue. DNA lesions were detected by Fpg that cleaves DNA at certain oxidized bases, and T4-endoV, which cleaves DNA at cyclobutane pyrimidine dimers and apurinic/apyrimidinic (AP) sites. These cleavages form open relaxed-DNA structures, which are discriminated from supercoiled-DNA. DHPNO2 or photoactivated-MB treatments result in similar plasmid damage profile: low number of single-strand breaks or AP-sites and high frequency of Fpg-sensitive sites; confirming that base oxidation is the main product for both reactions and that ¹O2 might be the most likely intermediate that reacts with DNA.

Genetic and phenotypic characterization of isolates of Pyricularia grisea from the rice cultivars epagri 108 and 109 in the State of Tocantins

An epidemic of rice (Oryza sativa) blast occurred on cultivars Epagri 108 and 109 in the municipalities of Lagoa da Confusão and Duerê in the State of Tocantins, during the rice-growing season 1998-99. DNA fingerprinting and virulence phenotype analysis were utilized to determine the diversity of Pyricularia grisea isolates collected from these cultivars in one epidemic year. Rep-PCR analysis of isolates was done by using two primer sequences from Pot2. Two distinct fingerprint groups or lineages were identified among 53 isolates collected from nine different commercial fields. The virulence pattern of isolates retrieved from these two cultivars was analyzed in artificial inoculation tests utilizing 32 genotypes in the greenhouse. A dendrogram constructed from virulence phenotype data showed a single group considering 77% similarity level. The predominant pathotype IB-45 was represented by 47 of the 53 isolates corresponding to 83%. Four other pathotypes (IB-1, IB-9, IB-13 and IB-41) were identified at random among the isolates from these cultivars. There was no relation between rep-PCR grouping and pathotypes. The results showed that the isolates of P. grisea recovered from cultivars Epagri108 and 109 in farmers' fields had narrow phenotypic and genetic diversity. The blast outbreak on these two cultivars one year after their introduction could be attributed to the new pathotype IB-45 or its increase, which was hitherto existing in low frequency.

Effect of trickle irrigation on root development of the wet bulb and 'pera' orange tree yield in the state of São Paulo, Brazil

The aim of this study was to evaluate the effect of different microirrigation designs on root system distribution in wet bulb region, orange orchard yield and quality of orange fruits. The experiment was installed as random blocks with five treatments and four replicates in an orchard of 'Pêra' orange trees grafted on 'Cleopatra' mandarin rootstock. The treatments consisted of: one drip line (T1), two drip lines (T2), four drip lines (T3) per planting row, microsprinkler irrigation (T4) and without irrigation (T5). Irrigation treatments favored yield and ºBrix. The treatment with a single drip line (T1) showed the greatest quantity of roots in relation to the treatments T2 and T3.

Environmental comfort in constructions for Sindi and Guzera calves in the agreste region of the State of Paraiba, Brazil

The objective of this study was to evaluate the quality of air, bioclimatic indexes of facilities and physiological indices of Guzera and Sindhi calves, reared in climatic conditions of Agreste. The study was conducted at the experimental station of Alagoinha, PB, Brazil, using 16 calves of Sindi and Guzerá races. The average concentration of oxygen (20.85%), ammonia (1.99 ppm), carbon monoxide (<0.01 ppm), methane (0.13 ppm) and hydrogen sulfide (<0.01) within facilities, were within the limits established by the Brazilian and international standards, for both animals and workers. The bioclimatic index of temperature and humidity and the temperature of the black globe and humidity index were within the thermal comfort zone for cattle in most of the experimental period, the mean values of respiratory frequency (26.0 min mov-1) and skin temperature (32.3 °C) were higher in the hottest time of the day (1 pm) and rectal temperature (39.3 ºC) in the late afternoon (5 pm), but remained within normal ranges for the studied races. The races have good adaptability to climatic conditions in the region of the Paraibano Agreste, Brazil.

Thermal performance and concentration of gases in facilities for pigs in semiarid region from State of Paraiba - Brazil

The study was conducted in a facility for pigs during the nursery and finishing in the town of 'Montadas', in the semiarid of the state of Paraiba, Brazil, in the rainy and dry season, aiming to evaluate the concentration of oxygen, methane, carbon monoxide and ammonia, and the bioclimatic indexes: ambient temperature (AT), relative humidity (RH) and the index of black globe temperature and humidity (IBGTH). These indexes differed significantly (P>0.05) between the periods and times. The AT in the rainy season was in the thermal comfort zone(TCZ) in most of the times in the nursery; for the finishing phase, thermal discomfort occurred; during the dry season, there was thermal comfort in the nursery phase; in the finishing phase the thermal discomfort occurred at all times. In the rainy season, the IBGTH was in TCZ; in the dry season, it was above the TCZ. The RH in the rainy period was in the TCZ; in the dry season, in most of the times, below the range of the TCZ. The concentration of gases showed no differences (P > 0.05) between periods and between the times, and the carbon monoxide, hydrogen sulfide and methane were below 1.0 ppm, and the ammonia showed a mean of 5.2 ppm. None of the analyzed gases exceeded the limits established by Brazilian and international standards for animals and workers.

Diarrhea outbreaks in suckling piglets due to rotavirus group C single and mixed (rotavirus groups A and B) infections

Porcine group A rotavirus (PoRVA) is a major cause of neonatal diarrhea in suckling and recently weaned piglets worldwide. The involvement of non-group A rotavirus in cases of neonatal diarrhea in piglets are sporadic. In Brazil there are no reports of the porcine rotavirus group C (PoRVC) as etiologic agent of the diarrhea outbreaks in piglets. The aim of this study was to describe the identification of rotavirus group C in single and in mixed infection with rotavirus groups A and B in three neonatal diarrhea outbreaks in suckling (<21-day-old) piglets, with 70% to 80% and 20% to 25% of morbidity and lethality rates, respectively, in three pig herds located in the state of Santa Catarina, Brazil. The diagnosis of PoRV in the diarrheic fecal samples was performed using polyacrylamide gel electrophoresis (PAGE) to identify the presence of porcine rotavirus groups A, B (PoRVB), and C, and by RT-PCR (PoRVA and PoRVC) and semi-nested (SN)-PCR (PoRVB) to partially amplify the VP4 (VP8*)-VP7, NSP2, and VP6 genes of PoRVA, PoRVB, and PoRVC, respectively. One RT-PCR (PoRVA and PoRVC) and SN-PCR (PoRVB) product of each group of rotavirus of each diarrhea outbreak was submitted to nucleotide (nt) sequence analysis. Based on the PAGE technique, 4 (25%) and 1 (6.25%) of the 16 diarrheic fecal samples evaluated in the first outbreak presented PoRVA and PoRVC electropherotype, respectively, and 11 (68.75%) were negative. In the second outbreak, 3 (42.85%) of the 7 fecal samples evaluated presented PoRVA electropherotype, and in 3 (42.85%) and in 1 (14.3%) fecal samples were detected inconclusive and negative results, respectively. Three (30%) of the 10 fecal samples of the third outbreak presented PoRVC electropherotype; 5 (50%) and 2 (20%) samples showed negative and inconclusive results, respectively. Based on the RT-PCR and SN-PCR assays in the first neonatal diarrhea outbreak, PoRVC was detected in 13 (81.2%) of the 16 diarrheic fecal samples evaluated. PoRVC single infection was identified in 4 (25%) of these samples and mixed infections with PoRVA and PoRVB in 9 (56.2%) fecal samples. All of the seven diarrheic fecal samples evaluated from the second neonatal diarrhea outbreak were positive for PoRVC, whereas its mixed infection with other PoRV groups was detected in 4 (57.2%) samples. In the third outbreak, PoRVC in single infection was detected in all of the 10 diarrheic fecal samples analyzed. In the nt sequence analysis, the PoRVA strains of the first and second outbreaks demonstrated higher nt identity with G4P[6] and G9P[23] genotypes, respectively. The PoRVB strains (first and second outbreaks) and the PoRVC strains (first, second, and third outbreaks) showed higher nt identity and clustered in the phylogenetic tree with PoRVB and PoRVC strains that belong to the N4 and I1 genotypes, respectively. This is the first description in Brazil of the involvement of PoRVC in the etiology of diarrhea outbreaks in suckling piglets. The results of this study demonstrated that PoRVC, in both single and mixed infections, is an important enteropathogen involved in neonatal diarrhea outbreaks in piglets and that the use of more sensitive diagnostic techniques allows the identification of mixed infections involving two or even three groups of PoRV, which may be more common than previously reported.