Detection of Salmonella spp. in wild and domestic birds in an anthropized ecotone between the Cerrado and the Amazon Forest in Brazil.

Emergence of zoonotic infectious diseases represent one of the main threats to people worldwide. To properly understand and prevent zoonoses is fundamental to study their epidemiology and the possibility of spillover events, especially for commercially intensive domestic animals and humans. Here, we studied 210 wild birds from the "Ipucas" region, which consists of fragments of the Amazon Forest interspersed with fragments of the "Cerrado" that is subject to seasonal flooding and 75 domestic birds from neighboring poultry farming. Then, we molecularly diagnosed Salmonella and Chlamydia from wild birds and poultry. Among the wild birds, four were diagnosed with Chlamydia psittaci and 23 with Salmonella spp., while we detected 15 poultry infected by Salmonella spp. and no poultry with C. psittaci. We highlighted the common infections of wild and domestic birds in an anthropologically modified environment and potential spillover of Salmonella pathogens among wild and livestock birds. Those infections can harm the health of native and domestic species.

Frequency of enterotoxins, toxic shock syndrome toxin-1, and biofilm formation genes in Staphylococcus aureus isolates from cows with mastitis in the Northeast of Brazil.

Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.

Prevalence and diversity of avian malaria parasites in migratory Black Skimmers (Rynchops niger, Laridae, Charadriiformes) from the Brazilian Amazon Basin.

The Medium Solimões River region in the Brazilian Amazon Basin is an area utilized for reproduction and nesting by a variety of species of migratory aquatic birds such as Black Skimmers (Rynchops niger). These migratory birds form mixed-species reproductive colonies with high population densities and exhibit a large range of migration routes. This study aimed to describe the prevalence and diversity of the avian malaria parasites Plasmodium and Haemoproteus in Black Skimmers, on the basis of the association between microscopic observation of blood smears and amplification of the mitochondrial cytochrome b gene (mtDNA cyt-b). The overall prevalence rates of the parasites for juvenile and adult bird specimens were 16% (5/31) and 22% (15/68), respectively. Sequencing the mtDNA cyt-b marker revealed two Plasmodium lineages, which had been previously described in different regions of the American continent, including a Neotropical region in Southeast Brazil, and one Haemoproteus lineage. The fact that avian malarial parasites have been found infecting the Black Skimmers in the Brazilian Amazon ecosystem, which exhibits considerable diversity, highlights the importance of these migratory birds as a potential source of infection and dispersion of pathogens to other susceptible birds of the Nearctic and Neotropical regions.

Renal changes in the early stages of diet-induced obesity in ovariectomized rats.

The relationship between obesity and renal lesions, especially in low estrogen levels, has been less documented. The aim of this study was to assess the renal changes in diet-induced obesity in ovariectomized rats. Wistar rats were ovariectomized or sham-operated and divided into four groups: sham-operated rats fed a standard diet (SSD); ovariectomized rats fed a standard diet (OSD); sham-operated rats fed a high-fat diet (SHFD); ovariectomized rats fed a high-fat diet (OHFD). Body weight and blood pressure were measured weekly. The rats were killed 24 weeks after initiation of standard or high-fat diet treatment, the kidneys were removed for immunohistochemical and histological studies. Blood and urine samples were collected to quantify sodium, potassium and creatinine. OHFD rats presented increases in visceral adipose tissue, serum insulin levels, blood pressure and proteinuria, and a decrease in fractional excretion of sodium as well. Histological and morphometric studies showed focal alterations in the renal cortex. Expression of macrophages, lymphocytes, nuclear factor-kappa B (NF-kappaB), Proliferating Cell Nuclear Antigen (PCNA), angiotensin II (ANG II) and vimentin was greater in OHFD rats than in control rats. Thus, these results demonstrate that the high-fat diet in ovariectomized rats promoted renal function and structure changes, renal interstitial infiltration of mononuclear cells and increased expression of ANG II and NF-kappaB.

Avian malaria in captive psittacine birds: detection by microscopy and 18S rRNA gene amplification.

A cross-sectional survey was conducted to estimate the occurrence of malaria infection among captive psittacine birds (n=127) from three zoological gardens in Brazil. Malaria infection was evaluated by the association of direct examination of blood smears with amplification of the 18SSU rRNA gene of the Plasmodium genus, demonstrating an overall occurrence of 36%. Most infected bird species were Amazona aestiva (28/73), Ara ararauna (6/10), and Amazona amazonica (3/10). The low parasitemias observed among the infected birds suggest a chronic infection. The sequence analyses of 10 isolates indicate a potential occurrence of four distinct Plasmodium lineages. These findings provide new data on malarial infection in captive psittacine birds, and emphasize the need for better control of importation and exportation of these birds.