Exposure to pesticides used in rice farming (bentazone, chlorantraniliprole and tebuconazole) affects biochemical biomarkers and hepatic histopathological parameters of hammertoad tadpoles (Boana faber).

Pesticides used in rice cultivation can cause negative health effects to non-target organisms representative of natural biodiversity. In this context, the present study aimed to investigate the occurrence of pesticides in surface waters from a river that flows in the middle of a rice farming-dominated area. We were also interested in evaluate biochemical and histological effects caused by exposure (16 d) to the lower and higher concentrations of the main found herbicide (bentazone, BTZ), insecticide (chlorantraniliprole, CTP) and fungicide (tebuconazole, TBZ), isolated or mixed, in Boana faber tadpoles. No significant differences were observed in the development of the animals. Tadpoles exposed to the herbicide BTZ showed higher hepatic levels of malondialdehyde (MDA). In animals exposed to CTP, MDA levels were lower than controls. Animals exposed to the fungicide TBZ showed higher hepatic activity of glutathione S-transferase and carboxylesterase (CbE), as well as higher levels of carbonyl proteins and MDA. Animals exposed to Mix showed higher activity in CbE and glucose-6-phosphate dehydrogenase activity in the liver, as well as higher levels of MDA. In the brain and muscle of tadpoles exposed to Mix, acetylcholinesterase activity was higher. Histological changes were also observed in pesticide-exposed animals, such as increased occurrence of melanomacrophages, inflammatory infiltrates and congestion. Our data evidences the contamination of natural aquatic environments by rice pesticides, and the adverse effects of main ones in B. faber tadpoles, which suggests the contribution of pesticides derived from rice cultivation to the degradation of local biodiversity health.

Diversity of gastrointestinal parasites and molecular characterization of Giardia duodenalis in free-living and captive howler monkeys (Alouatta guariba clamitans) in southern Brazil.

Non-human primates (NHPs) are the group that most share infectious agents with humans due to their close taxonomic relationship. The southern brown howler monkeys (Alouatta guariba clamitans) are endemic primates from Brazil and Argentina's Atlantic Forest. This study aimed to investigate the presence of intestinal parasites in free-living (FL) and captive (CA) southern brown howler monkeys. Thirty-nine stool samples were collected in two areas in southern Brazil, 15 FL and 24 CA. Stool sediments obtained by centrifugal sedimentation technique were used for microscopic analysis and direct immunofluorescence assay and evaluated by molecular analysis through amplification and sequencing of TPI fragments. Intestinal parasites Giardia duodenalis, Cryptosporidium spp., and Trypanoxyuris minutus were detected at coproparasitological analysis. This is the first report of the presence of Cryptosporidium spp. in free-living howlers. The molecular characterization of G. duodenalis isolates indicated assemblage B for the first time found in free-living A. guariba clamitans. The high prevalence of G. duodenalis transmission in CA howler monkeys can be explained by direct contact with humans and frequent soil contact. The presence of a potentially zoonotic assemblage in these animals indicates that the process of fragmentation and cohabitation with humans and livestock affects the wildlife, thus indicating a need for eco-health measures.

IgM antibody responses against Plasmodium antigens in neotropical primates in the Brazilian Atlantic Forest.

Introduction: Zoonotic transmission is a challenge for the control and elimination of malaria. It has been recorded in the Atlantic Forest, outside the Amazon which is the endemic region in Brazil. However, only very few studies have assessed the antibody response, especially of IgM antibodies, in Neotropical primates (NP). Therefore, in order to contribute to a better understanding of the immune response in different hosts and facilitate the identification of potential reservoirs, in this study, naturally acquired IgM antibody responses against Plasmodium antigens were evaluated, for the first time, in NP from the Atlantic Forest. Methods: The study was carried out using 154 NP samples from three different areas of the Atlantic Forest. IgM antibodies against peptides of the circumsporozoite protein (CSP) from different Plasmodium species and different erythrocytic stage antigens were detected by ELISA. Results: Fifty-nine percent of NP had IgM antibodies against at least one CSP peptide and 87% against at least one Plasmodium vivax erythrocytic stage antigen. Levels of antibodies against PvAMA-1 were the highest compared to the other antigens. All families of NP showed IgM antibodies against CSP peptides, and, most strikingly, against erythrocytic stage antigens. Generalized linear models demonstrated that IgM positivity against PvCSP and PvAMA-1 was associated with PCR-detectable blood-stage malaria infection and the host being free-living. Interestingly, animals with IgM against both PvCSP and PvAMA-1 were 4.7 times more likely to be PCR positive than animals that did not have IgM for these two antigens simultaneously. Discussion: IgM antibodies against different Plasmodium spp. antigens are present in NP from the Atlantic Forest. High seroprevalence and antibody levels against blood-stage antigens were observed, which had a significant association with molecular evidence of infection. IgM antibodies against CSP and AMA-1 may be used as a potential marker for the identification of NP infected with Plasmodium, which are reservoirs of malaria in the Brazilian Atlantic Forest.

Detection of Plasmodium simium gametocytes in non-human primates from the Brazilian Atlantic Forest.

BACKGROUND: Plasmodium species of non-human primates (NHP) are of great interest because they can naturally infect humans. Plasmodium simium, a parasite restricted to the Brazilian Atlantic Forest, was recently shown to cause a zoonotic outbreak in the state of Rio de Janeiro. The potential of NHP to act as reservoirs of Plasmodium infection presents a challenge for malaria elimination, as NHP will contribute to the persistence of the parasite. The aim of the current study was to identify and quantify gametocytes in NHP naturally-infected by P. simium. METHODS: Whole blood samples from 35 NHP were used in quantitative reverse transcription PCR (RT-qPCR) assays targeting 18S rRNA, Pss25 and Pss48/45 malaria parasite transcripts. Absolute quantification was performed in positive samples for 18S rRNA and Pss25 targets. Linear regression was used to compare the quantification cycle (Cq) and the Spearman's rank correlation coefficient was used to assess the correlation between the copy numbers of 18S rRNA and Pss25 transcripts. The number of gametocytes/µL was calculated by applying a conversion factor of 4.17 Pss25 transcript copies per gametocyte. RESULTS: Overall, 87.5% of the 26 samples, previously diagnosed as P. simium, were positive for 18S rRNA transcript amplification, of which 13 samples (62%) were positive for Pss25 transcript amplification and 7 samples (54%) were also positive for Pss48/45 transcript. A strong positive correlation was identified between the Cq of the 18S rRNA and Pss25 and between the Pss25 and Pss48/45 transcripts. The 18S rRNA and Pss25 transcripts had an average of 1665.88 and 3.07 copies/µL, respectively. A positive correlation was observed between the copy number of Pss25 and 18S rRNA transcripts. Almost all gametocyte carriers exhibited low numbers of gametocytes (< 1/µL), with only one howler monkey having 5.8 gametocytes/µL. CONCLUSIONS: For the first time, a molecular detection of P. simium gametocytes in the blood of naturally-infected brown howler monkeys (Alouatta guariba clamitans) was reported here, providing evidence that they are likely to be infectious and transmit P. simium infection, and, therefore, may act as a reservoir of malaria infection for humans in the Brazilian Atlantic Forest.

Plasmodium infection and its association with biochemical and haematological parameters in free-living Alouatta guariba clamitans (Cabrera, 1940) (Primates: Atelidae) in Southern Brazil.

BACKGROUND: The influence of Plasmodium spp. infection in the health of Southern brown howler monkey, Alouatta guariba clamitans, the main reservoir of malaria in the Atlantic Forest, is still unknown. OBJECTIVES: The aim of this study was to investigate the positivity rate of Plasmodium infection in free-living howler monkeys in an Atlantic Forest fragment in Joinville/SC and to associate the infection with clinical, morphometrical, haematological and biochemical alterations. METHODS: Molecular diagnosis of Plasmodium infection in the captured monkeys was performed by Nested-polymerase chain reaction (PCR) (18S rRNA and coxI). Haematological and biochemical parameters were compared among infected and uninfected monkeys; clinical and morphometrical parameters were also compared. FINDINGS: The positivity rate of Plasmodium infection was 70% among forty captured animals, the highest reported for neotropical primates. None statistical differences were detected in the clinical parameters, and morphometric measures comparing infected and uninfected groups. The main significant alteration was the higher alanine aminotransferase (ALT) levels in infected compared to uninfected monkeys. MAIN CONCLUSIONS: Therefore, Plasmodium infection in howler monkeys may causes haematological/biochemical alterations which might suggest hepatic impairment. Moreover, infection must be monitored for the eco-epidemiological surveillance of malaria in the Atlantic Forest and during primate conservation program that involves the animal movement, such as translocations.

Hematological and serum biochemistry data on southern brown howler monkeys (Alouatta guariba clamitans) in captivity in Brazil.

BACKGROUND: Physiological values reflect the health condition and responses of individuals to handling in captivity. The aim of this study was to establish hematological and serum biochemistry parameters of clinically healthy animals of the Alouatta guariba clamitans subspecies. METHODS: We collected blood samples from adult males and females kept at the Center for Biological Research of Indaial after chemical containment with 3.9 mg/kg of tiletamine hydrochloride and zolazepam. RESULTS: Significant differences between males and females were found in the levels of erythrocytes, hemoglobin, hematocrit, lymphocytes, neutrophils, platelets, mean corpuscular hemoglobin concentration (MCHC), and gamma-glutamyltranspeptidase (GGT). CONCLUSIONS: Our results suggest the existence of sexual dimorphism in some physiological parameters of A guariba clamitans. The parameters reported herein can be used as reference values for other populations kept under similar conditions.