Biochemical responses of Echinochloa polystachya inoculated with a Trichoderma consortium during the removal of a pyrethroid-based pesticide.

The biochemical response of plants exposed to pesticides and inoculated with microorganisms is of great importance to explore cleaning up strategies for contaminated sites with pyrethroid-based pesticides. We evaluated the effects of a Trichoderma consortium on the biochemical responses of Echinochloa polystachya plants during the removal of a pyrethroid-based pesticide. Plants were inoculated or not with the Trichoderma consortium and exposed to commercial pesticide H24®, based on pyrethroids. Pesticide application resulted in significant reduction in root protein content (58%), but enhanced content of malondialdehyde (MDA) in shoots, superoxide dismutase (SOD) activity in shoots and roots, and catalase (CAT) activity in roots. Inoculation of Trichoderma consortium in E. polystachya exposed to the pesticide resulted in increased protein content in roots and MDA content in shoots (2-fold). Trichoderma consortium improved protein content and SOD activity (140-fold) in plants. Fungal inoculation increased the removal (97.9%) of the pesticide in comparison to the sole effect of plants (33.9%). Results allow further understanding about the responses of the interaction between plants and root-associated fungi to improving the assisted-phytoremediation of solid matrices contaminated with organic pesticides.

This original paper describes the positive role of the Trichoderma sp. consortium on favoring the removal of a pyretrhoid-based pesticide. This is one of first reports on analyzing the influence of a Trichoderma consortium on the oxidative stress and antioxidant response of Echinochloa polystachya in presence of the pesticide. This experimental approach provides a new alternative for further fungal assisted-phytoremediation of a pyretrhoid-based pesticide.

Growth, tolerance, and enzyme activities of Trichoderma strains in culture media added with a pyrethroids-based insecticide.

The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as Trichoderma, which contribute to the biocontrol of several fungal phytopathogens. This research evaluated the tolerance of several strains of Trichoderma to a selected culture medium contaminated with a commercial insecticide (H24®) composed of pyrethroids, permethrin and prallethrin, and carbamate propoxur, and determined the influence of this insecticide on the release of enzymes such as chitinases, peroxidases, and endoglucanases by a consortium of selected Trichoderma strains grown in liquid culture medium. Four out of 10 Trichoderma strains showed tolerance to 200ppm (∼48.3% of growth) of the commercial insecticide after 96h of exposure to a contaminated solid medium. After eight days of growth in liquid culture, the insecticide enhanced extracellular protein content and peroxidase activities in the Trichoderma consortium but decreased both chitinase and glucanase activities. These fungal responses should be considered when implementing strategies that combine alternative pesticides and fungal biocontrollers for managing fungal phytopathogens.

Short-Term Evaluation of the Spatial Distribution of Trophic Groups of Amoebae in the Rhizosphere of Zea mays Inoculated with Rhizophagus intraradices.

Primary production in terrestrial ecosystems is sustained by plants, microbiota, and fungi, which are the major organic matter providers in the root zone, setting in motion the soil food webs. Predators like soil amoebae voraciously feed on bacteria, fungi, and microbial eukaryotes releasing the nutrients sequestered in their biomass. Early food web setting up is crucial for seedling nutrition and its further development after establishment. Mycorrhizal fungi are more than phosphorus providers, and we wonder what their role is in structuring the predators' trophic groups in the root zone. We evaluated the effect of Rhizophagus intraradices inoculated in Zea mays (mycorrhizosphere), on the structuration of amoebae trophic groups along vertical and horizontal (3, 6, and 9 cm) soil distribution when compared to un-inoculated plants, after 20 days in microcosms. Amoebae species richness was highest in non-mycorrhizal seedlings in the root zone at 6- to 9-cm depth, and 3 cm away from plants. More bacterial species are needed when plants are devoid of mycorrhiza, and their influence is constrained 3 cm away from roots. Higher diversity of trophic groups was recorded at mycorrhizal seedlings and at the compartment influenced by the mycelium at 6- to 9-cm depth. The highest bacterivorous diversity, higher number of rare species and protozoa-eating amoebae, and the absence of fungivorous group recorded at the mycorrhizosphere of Z. mays, indicate that the community was very different from the non-mycorrhizal plants. We conclude that the arbuscular mycorrhizal fungus exerts significant changes on the community of trophic groups of amoebae.

Cellulase and chitinase activities and antagonism against Fusarium oxysporum f.sp. cubense race 1 of six Trichoderma strains isolated from Mexican maize cropping.

OBJECTIVE: To evaluate the enzymatic and biocontrol capacity of native Trichoderma strains isolated from corn crops in Irapuato (state of Guanajuato) and Napízaro (state of Michoacán), Mexico. RESULTS: Six native strains from Irapuato and Napízaro were tested, with five of them identified as T. harzianum and one as T. tomentosum. The six strains qualitatively and quantitatively showed enzyme activity for cellulase and chitinase. The best results were obtained for strains IrV6SIC7 and MichV6S2C2 with 878 IU L-1 of chitinase and 1323 IU L-1 of cellulase, respectively. All Trichoderma strains acted antagonistically toward Fusarium oxysporum f.sp. cubense race 1 (FocR1), with percentages of inhibition that ranged from 9 to 54%. In addition, the microscopic analysis allowed visualizing the mechanisms of mycoparasitism and antibiosis by either IrV6SIC7 or MichV6S2C2. The latter effects indicate that the tested native Trichoderma strains isolated from corn crops possessed enzymatic mechanisms as a strategy for biocontrolling FocR1 strains. CONCLUSION: The enzyme production by the Trichoderma strains represents a potential biotechnological utilization for either agricultural or industrial purposes.

Phytoremediation of soil contaminated with weathered petroleum hydrocarbons by applying mineral fertilization, an anionic surfactant, or hydrocarbonoclastic bacteria.

This study evaluated the effect of the application of mineral fertilization (F), the anionic surfactant Triton X-100 (TX100), or the inoculation with a hydrocarbooclastic bacterial consortium (BCons) on the growth of Clitoria ternatea during the phytoremediation of a Gleysol contaminated with weathered petroleum hydrocarbons (39,000 mg kg-1 WPH) collected from La Venta, Tabasco (Mexico). The experiment consisted of a completely randomized design with seven treatments and four replications each under greenhouse conditions. The application of F (biostimulation) increased plant growth and biomass production; in contrast, TX100 only favored root biomass (11%) but significantly favored WPH degradation. Bioaugmentation with BCons did not show significant effects on plant growth. Nevertheless, the combination of biostimulation with bioaugmentation (BCons + F, BCons + TX100, and BCons + F+TX100) enhanced plant growth, hydrocarbonoclastic bacteria population, and WPH degradation when compared to treatments with the single application of bioaugmentation (BCons) or biostimulation (F).

Application of mineral fertilization and commercial surfactant favored root biomass and degradation of weathered petroleum hydrocarbons (WPH). The reintroduction of hydrocarbonoclastic and surfactant-producer bacteria did not enhance plant growth but significantly contributed on WPH degradation from a chronically contaminated soil.

Platelet depletion does not alter the course of Brucella abortus infection in vivo.

Brucellosis is a bacterial disease of animals and a zoonotic infection. Thrombocytopenia is a common outcome in long-lasting brucellosis in humans. Likewise, ex vivo experiments have shown that platelets may play a role in Brucella abortus infections. Following these reports, we explored the course of brucellosis in thrombocytopenic mice, using the non-toxic low-molecular-weight aspercetin protein that depletes platelets in vivo. Aspercetin does not induce systemic hemorrhage or inflammation, and when injected into mice, it generates a rapid dose-dependent drop in platelet counts without affecting central organs, disrupting hematological parameters, or the proinflammatory cytokine profile. Compared to the B. abortus infected control group, the infected thrombocytopenic mice did not show significant differences in the hematological profiles, pathological score, spleen, liver histopathology, or bacterial loads. Except for IL-6, which was higher in the infected thrombocytopenic mice, the TNF-α, IFN-γ and IL-10 did not significantly differ with the PBS-infected group. The results indicate that platelets do not play a significant role in modulating Brucella infection in vivo at the early stages of infection, which is commensurate with the stealthy strategy followed by Brucella organisms at the onset of the disease.

Effect of Predation by Colpoda sp. in Nitrogen Fixation Rate of Two Free-Living Bacteria.

Biological nitrogen fixation is limited to several groups of prokaryotes, some of them reduce nitrogen as free-living nitrogen-fixing bacteria. Protozoa predation on these latter releases sequestered nitrogen that may enhance the formation of new bacterial biomass and possibly increase nitrogen fixation within soil microbial communities. We aim to evaluate the predation effect of Colpoda sp. on two nitrogen fixers: Azospirillum lipoferum and Stenotrophomonas sp. during their lag, early exponential, and exponential phases. The kinetics of bacterial population growth was determined in the predators' presence or absence and the effect of predation on the rate of N fixation was evaluated through the reduction of acetylene to ethylene technique. Colpoda sp. showed a non-significant difference in preferences between the two species offered as prey. Consequently, the abundance of A. lipoferum and Stenotrophomonas sp. decreased significantly due to predator's pressure and both species responded by increasing their specific growth rate. Likewise, predation promoted greater nitrogen fixation rate by CFU during the lag phase in A. lipoferum (0.20 nM/CFU with predation vs 0.09 nM/CFU without predation) and Stenotrophomonas sp. (0.22 nM/CFU vs 0.09 nM/CFU respectively). During early exponential phase (29 h), the rate diminished to 0.13 and 0.05 nM/CFU in A. lipoferum and to 0.09 nM/CFU and 0.05 nM/CFU in Stenotrophomonas sp. Finally, during the exponential phase (52 h), only A. lipoferum without predation produced 0.003 nM/CFU of ethylene. Thus, the nitrogenase activity was higher in the lag and the early exponential phases when predator activity was involved.

Growth and lead uptake by Parkinsonia aculeata L. inoculated with Rhizophagus intraradices.

The increased lead (Pb) pollution in the biosphere has resulted in serious environmental problems, so it is essential to evaluate phytoremediation strategies for contaminated soils. This study evaluated the growth and Pd absorption capacity of Pakinsonia aculeata, inoculated with an arbuscular mycorrhizal fungus (Rhizophagus intraradices) over 18 weeks under greenhouse conditions. Treatments included inoculated and non-inoculated plants combined with six Pb concentrations (0, 40, 80, 160, 320, 640 mg·L-1) in the form of Pb(NO3)2. Results showed that mycorrhizal colonization in inoculated plants ranged from 5.0 to 6.7% and favored plant growth. Pb levels and AMF-inoculation had no effects on chlorophyll fluorescence values. AMF-plants absorbed significantly more Pb in roots (237.97 mg·kg-1) than control plants (202.85 mg·kg-1), as well as high translocation to shoots (27.02 mg·kg-1) under the high Pb dose. The increase in Pb concentration reduced the P concentration in roots, and the P and N concentrations in shoots; however, the absorption and translocation of Ca and Mg was increased in shoots. Inoculation of R. intraradices improved both growth and Pb uptake of P. aculeata, under greenhouse conditions suggesting that this tree species may be potentially studied for detoxifying Pb-polluted soils.

Neutrophils Dampen Adaptive Immunity in Brucellosis.

Brucella organisms are intracellular stealth pathogens of animals and humans. The bacteria overcome the assault of innate immunity at early stages of an infection. Removal of polymorphonuclear neutrophils (PMNs) at the onset of adaptive immunity against Brucella abortus favored bacterial elimination in mice. This was associated with higher levels of interferon gamma (IFN-γ) and a higher proportion of cells expressing interleukin 6 (IL-6) and inducible nitric oxide synthase (iNOS), compatible with M1 macrophages, in PMN-depleted B. abortus-infected (PMNd-Br) mice. At later times in the acute infection phase, the amounts of IFN-γ fell while IL-6, IL-10, and IL-12 became the predominant cytokines in PMNd-Br mice. IL-4, IL-1ß, and tumor necrosis factor alpha (TNF-α) remained at background levels at all times of the infection. Depletion of PMNs at the acute stages of infection promoted the premature resolution of spleen inflammation. The efficient removal of bacteria in the PMNd-Br mice was not due to an increase of antibodies, since the immunoglobulin isotype responses to Brucella antigens were dampened. Anti-Brucella antibodies abrogated the production of IL-6, IL-10, and IL-12 but did not affect the levels of IFN-γ at later stages of infection in PMNd-Br mice. These results demonstrate that PMNs have an active role in modulating the course of B. abortus infection after the adaptive immune response has already developed.

Microbial Bioleaching of Ag, Au and Cu from Printed Circuit Boards of Mobile Phones.

Electronic waste (E-Waste) is consumed at high speed in the world. These residues contain metals that increase their price each year, generating new research on the ability of microorganisms to recover the metals from these wastes. Therefore, this work evaluated the biologic lixiviation of Cu, Ag and Au from printed circuit boards (PCB) of mobile phones by three strains of Aspergillus niger, Candida orthopsilosis, Sphingomonas sp. and their respective consortia, in addition to leaching with citric acid. The microorganisms were cultured in mineral media with 0.5 g of PCB, and the treatments with 1M citric acid were added the same amount of PCB. All treatments were incubated for 35 days at room temperature. The results showed that Sphingomonas sp. MXB8 and the consortium of C. orthopsilosis MXL20 and A. niger MXPE6 can increase their dry biomass by 147% and 126%, respectively, in the presence of PCB. In the bioleaching of metals, the inoculation of A. niger MXPE6, the consortium of Sphingomonas sp. MXB8/C. orthopsilosis MXL20 and Sphingomonas sp. MXB8 leached 54%, 44.2% and 35.8% of Ag. The consortium of A. niger MX5 and A. niger MXPE6 showed a leaching of 0.53% of Au. A. niger MX5 leaching 2.8% Cu. Citric acid increased Cu leaching by 280% compared to treatments inoculated with microorganisms. Although further research is required, A. niger MXPE6 and the consortium of Sphingomonas sp. MXB8/C. orthopsilosis MXL20 could be an alternative to recover Ag from PCB of mobile phones.

[Responses of the common bean (Phaseolus vulgaris L.) and Rhizobium tropici CIAT899 symbiosystem to induced allelopathy by Ipomoea purpurea L. Roth]. / Respuesta del simbiosistema frijol (Phaseolus vulgaris L.) y Rhizobium tropici CIAT899 ante el efecto alelopático de Ipomoea purpurea L. Roth.

Allelopathy is a phenomenon that involves the production of secondary metabolites that influence the growth of plants and microorganisms; however, this alellopathic effect has been scarcely studied on the rhizobia-legume symbiosis. The aims of this research were 1) to assess the allelopathic potential of aqueous extracts of Ipomoea purpurea L. Roth on seed germination and root length of common bean seedlings (Phaseolus vulgaris L.), 2) to determine its effects on the in vitro growth of Rhizobium tropici CIAT899, and 3) to evaluate the allelopathic potential of I. purpurea on the growth, nodulation and physiology of common bean plants inoculated with R. tropici. After 48h, 15% of the aqueous root extract of I. purpurea stimulated seed germination, whereas 4% of the aqueous shoot extracts stimulated such germination. Both the root or shoot extracts stimulated seed germination and e root length. In vitro growth of R. tropici was inhibited as a result of the application of both aqueous extracts. The presence of I. purpurea negatively affected both the growth and physiological responses of common bean plants, and this effect was attenuated after the inoculation of R. tropici; nevertheless, this allelopathic plant affected root nodulation. Our results suggest that the symbiosis of rhizobia and roots of common bean plants is an important element for attenuating the negative effects caused by the allelopathic plant.

Depletion of Complement Enhances the Clearance of Brucella abortus in Mice.

Brucellosis is a bacterial disease of animals and humans. Brucella abortus barely activates the innate immune system at the onset of infection, and this bacterium is resistant to the microbicidal action of complement. Since complement stands as the first line of defense during bacterial invasions, we explored the role of complement in B. abortus infections. Brucella abortus-infected mice depleted of complement with cobra venom factor (CVF) showed the same survival rate as mice in the control group. The complement-depleted mice readily eliminated B. abortus from the spleen and did so more efficiently than the infected controls after 7 days of infection. The levels of the proinflammatory cytokines tumor necrosis factor alpha and interleukin-6 (IL-6) remained within background levels in complement-depleted B. abortus-infected mice. In contrast, the levels of the immune activator cytokine gamma interferon and the regulatory cytokine IL-10 were significantly increased. No significant histopathological changes in the liver and spleen were observed between the complement-depleted B. abortus-infected mice and the corresponding controls. The action exerted by Brucella on the immune system in the absence of complement may correspond to a broader phenomenon that involves several components of innate immunity.

Induced accumulation of Au, Ag and Cu in Brassica napus grown in a mine tailings with the inoculation of Aspergillus niger and the application of two chemical compounds.

This study evaluated the ability of Brassica napus for extracting gold (Au), silver (Ag) and copper (Cu) from a mine tailings, with the inoculation of two Aspergillus niger strains, and the application of ammonium thiocyanate (NH4SCN) or ammonium thiosulfate [(NH4)2S2O3]. After seven weeks of growth inoculated or non-inoculated plants were applied with 1 or 2 g kg-1 of either NH4SCN or (NH4)2S2O3, respectively. Eight days after the application of the chemical compounds, plants were harvested for determining the total dry biomass, and the content of Au, Ag, and Cu in plant organs. Application of (NH4)2S2O3 or NH4SCN resulted in enhanced Au-accumulation in stems (447% and 507%, respectively), while either (NH4)2S2O3+Aspergillus, or NH4SCN increased the Au-accumulation in roots (198.5% and 404%, respectively) when compared to the control. Treatments with (NH4)2S2O3 or (NH4)2S2O3+Aspergillus significantly increased (P ≤ 0.001) the accumulation of Ag in leaves (677% and 1376%, respectively), while NH4SCN + Aspergillus, and (NH4)2S2O3 enhanced the accumulation in stems (7153% and 6717.5%). The Ag-accumulation in roots was stimulated by NH4SCN+ Aspergillus, and (NH4)2S2O3+ Aspergillus (132.5% and 178%, respectively), when compared to the control. The combination of NH4SCN+Aspergillus significantly enhanced the Cu-accumulation in leaves (228%); whereas NH4SCN+ Aspergillus, or (NH4)2S2O3+ Aspergillus resulted in greater accumulation of Cu in stems (1233.5% and 1580%, respectively) than the control. Results suggest that either NH4SCN or (NH4)2S2O3 (with or without Aspergillus) improved the accumulation of Au and Ag by B. napus. Accumulation of Au and Ag in plant organs overpassed the hyperaccumulation criterion (> 1 mg kg-1 of plant biomass); whereas Cu-accumulation in stems and roots also overpassed such criterion (> 1000 mg kg-1) by applying either NH4SCN or (NH4)2S2O3 + A. niger.

Lead phytoextraction from printed circuit computer boards by Lolium perenne L. and Medicago sativa L.

This work assessed the ability of Lolium perenne and Medicago sativa for extracting lead (Pb) from particulate printed circuit computer boards (PCB) mixed in sand with the following concentrations: 0.5, 1.0 and 1.5 g of PCB, and including a control treatment without PCB. The PCB were obtained from computers, and grinded in two particle sizes: 0.0594 mm (PCB1) and 0.0706 mm (PCB2). The PCB particle sizes at their corresponding concentrations were applied to L. perenne and M. sativa by using three experimental assays. In assay II, PCB2 affected the biomass production for both plants. For assay III, the PCB1 increased the biomass of M. sativa (236.5%) and L. perenne (142.2%) when applying either 0.5 or 1.0 g, respectively. In regards to phytoextraction, assay I showed the highest Pb-extraction by roots of L. perenne (4.7%) when exposed to 1.5 g of PCB1. At assay I, L. perenne showed a Pb-bioconcentration factor higher than 1.0 when growing at 0.5 g of PCB1, and when HNO3 was used as digestion solution; moreover, in assay III both plants showed a Pb-translocation factor higher than 1.0. Therefore, Lolium perenne and Medicago sativa are able to recover Pb from electronic wastes (PCB).

[Growth and photochemical efficiency of photosystem ii in seedlings of two varieties of Capsicum annuum L. inoculated with rhizobacteria and arbuscular mycorrhizal fungi]. / Crecimiento y eficiencia fotoquímica del fotosistema ii en plántulas de 2 variedades de Capsicum annuum L. inoculadas con rizobacterias u hongos micorrícicos arbusculares.

Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are a biological alternative for the sustainable management of Capsicum annuum L. This research work evaluated the effects of both PGPR and AMF on bell pepper and jalapeno pepper plants. Five bacterial strains isolated from several locations in Estado de Mexico were used: [P61 (Pseudomonas tolaasii), A46 (P. tolaasii), R44 (Bacillus pumilus), BSP1.1 (Paenibacillus sp.), and OLs-Sf5 (Pseudomonas sp.)], and three treatments with AMF [H1 (consortium isolated from pepper crops in the State of Puebla), H2 (Rhizophagus intraradices), and H3 (consortium isolated from the rhizosphere of lemon trees, State of Tabasco)]. In addition, a fertilized treatment (Steiner nutrient solution at 25%) and an unfertilized control were included. Seedlings of "Caloro" jalapeno pepper and "California Wonder" bell pepper were inoculated with AMF at seed sowing, and PGPR were inoculated after 15 days of seedling emergence; seedlings were grown under plant growth chamber conditions. P61 bacterium and H1 AMF consortia were the most effective microorganisms for jalapeno pepper whereas R44 bacterium and AMF H3 and H1 were the most effective for bell peppers, when compared to the unfertilized control. Furthermore, P61 and R44 bacteria showed beneficial effects on PSII efficiency.

[Production of a compost accelerator inoculant]. / Generación de un inoculante acelerador del compostaje.

Composting was performed using a mixture of ovine manure and straw. Inoculum was extracted at five different phases of the composting process (18, 23, 28, 33 and 38 days after the start of the composting process) and its effect on reducing biotransformation time was evaluated in the composted ovine manure. The samples were preserved in a deep freezer, then lyophilized to obtain the inoculum, 50g of which was added to each treatment in the second experimental phase. Six treatments were established; C=straw (P)+ovine manure (E), T1=P+ E+inoculum 18 days after the start of the composting process (I18), T2=P+E+I23, T3=P+E+I28, T4=P+E+I33, T5=P+E+I38, with three replications. Treatments were placed in a controlled-environment chamber at 45% relative humidity and 30°C along with flasks containing 50g of material to measure daily production, CO2 accumulation, temperature, pH, electric conductivity (dS/m), organic matter (%), total nitrogen (%), total carbon (%), C: N ratio, particle size (Tp) and bulk density (g/l). CO2 production (mg) showed a significant difference (p ≤.05) of treatments T2 and T5 with respect to the others, which demonstrated that the inoculum of these treatments accelerated the dynamics of microorganisms and the composting process. The quality and maturity of the compost are guaranteed as the amount of CO2 decreases.

Brucella canis is an intracellular pathogen that induces a lower proinflammatory response than smooth zoonotic counterparts.

Canine brucellosis caused by Brucella canis is a disease of dogs and a zoonotic risk. B. canis harbors most of the virulence determinants defined for the genus, but its pathogenic strategy remains unclear since it has not been demonstrated that this natural rough bacterium is an intracellular pathogen. Studies of B. canis outbreaks in kennel facilities indicated that infected dogs displaying clinical signs did not present hematological alterations. A virulent B. canis strain isolated from those outbreaks readily replicated in different organs of mice for a protracted period. However, the levels of tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-12 in serum were close to background levels. Furthermore, B. canis induced lower levels of gamma interferon, less inflammation of the spleen, and a reduced number of granulomas in the liver in mice than did B. abortus. When the interaction of B. canis with cells was studied ex vivo, two patterns were observed, a predominant scattered cell-associated pattern of nonviable bacteria and an infrequent intracellular replicative pattern of viable bacteria in a perinuclear location. The second pattern, responsible for the increase in intracellular multiplication, was dependent on the type IV secretion system VirB and was seen only if the inoculum used for cell infections was in early exponential phase. Intracellular replicative B. canis followed an intracellular trafficking route undistinguishable from that of B. abortus. Although B. canis induces a lower proinflammatory response and has a stealthier replication cycle, it still displays the pathogenic properties of the genus and the ability to persist in infected organs based on the ability to multiply intracellularly.

Neutrophils exert a suppressive effect on Th1 responses to intracellular pathogen Brucella abortus.

Polymorphonuclear neutrophils (PMNs) are the first line of defense against microbial pathogens. In addition to their role in innate immunity, PMNs may also regulate events related to adaptive immunity. To investigate the influence of PMNs in the immune response during chronic bacterial infections, we explored the course of brucellosis in antibody PMN-depleted C57BL/6 mice and in neutropenic mutant Genista mouse model. We demonstrate that at later times of infection, Brucella abortus is killed more efficiently in the absence of PMNs than in their presence. The higher bacterial removal was concomitant to the: i) comparatively reduced spleen swelling; ii) augmented infiltration of epithelioid histiocytes corresponding to macrophages/dendritic cells (DCs); iii) higher recruitment of monocytes and monocyte/DCs phenotype; iv) significant activation of B and T lymphocytes, and v) increased levels of INF-γ and negligible levels of IL4 indicating a balance of Th1 over Th2 response. These results reveal that PMNs have an unexpected influence in dampening the immune response against intracellular Brucella infection and strengthen the notion that PMNs actively participate in regulatory circuits shaping both innate and adaptive immunity.

Case report: Renal adenoma in a captive ocelot (Leopardus pardalis) in Costa Rica.

Reports of renal neoplasia are rare in neotropical wildcats. Ocelots (Leopardus pardalis) are medium-sized wildcats living in America's tropical forests. A 12-year-old captive ocelot was diagnosed with a renal mass occupying approximately 25% of the total right kidney volume. The tissue was stained with routine hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS). Immunohistochemistry with the following markers was performed: cytokeratin (CK) AE1/AE3, CK19, CK 7, CD10, vimentin, Melan A, HMB45, Pax-8, and Wilms' tumor 1 (WT1). Histopathology revealed a well-differentiated epithelial tubular neoplasia with less than one mitotic figure per 2.37mm2 field. Vimentin and Pax-8 were the only positive markers. Immunohistochemically, neoplasia was diagnosed as a renal adenoma. Renal adenomas are seldom reported in neotropical wildcats. Reports on wild species are valuable for properly establishing a clinical prognosis for captive species. To the best of our knowledge, this is the first report that provides detailed microscopic and immunohistochemical descriptions of renal adenoma in a captive ocelot.

Molecular, morphological and histopathological evidence of Spirometra mansoni in wild and domestic animals from Costa Rica.

Spirometra mansoni is a diphyllobothroid cestode and one of the causing agents of sparganosis, a zoonotic foodborne and waterborne infection in humans. This parasite has an indirect life cycle with domestic and wild canids or felids as definitive hosts. The last report of S. mansoni in Costa Rica was done in 2004 by morphological assessment of worms, whereas molecular evidence of this species was obtained recently in the Americas. Herein, we present seven cases of spirometrosis in four dogs, three cats and a coyote from different regions of Costa Rica occurring in a time span of a year. Dog cases presented vomiting, hyporexia, lethargy and diarrhea, whereas cats were mostly asymptomatic. Moreover, the coyote was found with Spirometra sp. proglottids incidentally. Cytochrome oxidase subunit 1 (cox1) sequences of eggs or proglottids derived from all cases were analyzed with a Bayesian Inference phylogenetic tree and a haplotype network. These analyses showed the clustering of S. mansoni from Costa Rica with other sequences derived from Asia and America. Moreover, cox1 sequences clustered in two separate haplotypes, suggesting the high genetic diversity of the species. The present cases represent the first molecular evidence of the parasite in Central America; thus, extending its known range in the American continent.