Biologically synthesized silver nanoparticles as potent antibacterial effective against multidrug-resistant Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the most worrisome infectious bacteria due to its intrinsic and acquired resistance against several antibiotics and the recalcitrance of its infections; hence, the development of novel antimicrobials effective against multidrug-resistant P. aeruginosa is mandatory. In this work, silver nanoparticles obtained by green synthesis using a leaf extract and fungi were tested against a battery of clinical strains from cystic fibrosis, pneumonia and burnt patients, some of them with multidrug resistance. Both nanoparticles showed a potent antibacterial effect, causing severe damage to the cell wall, membrane and DNA, and inducing the production of reactive oxygen species. Moreover, the nanoparticles derived from fungi showed synergistic antibacterial effects with the antibiotics meropenem and levofloxacin for some clinical strains and both kinds of nanoparticles were nontoxic for larvae of the moth Galleria mellonella, encouraging further research for their implementation in the treatment of P. aeruginosa infections.

Taenia solium tapeworms synthesize corticosteroids and sex steroids in vitro.

Cysticercosis is a disease caused by the larval stage of Taenia solium cestodes that belongs to the family Taeniidae that affects a number of hosts including humans. Taeniids tapeworms are hermaphroditic organisms that have reproductive units called proglottids that gradually mature to develop testis and ovaries. Cysticerci, the larval stage of these parasites synthesize steroids. To our knowledge there is no information about the capacity of T. solium tapeworms to metabolize progesterone or other precursors to steroid hormones. Therefore, the aim of this paper was to investigate if T. solium tapeworms were able to transform steroid precursors to corticosteroids and sex steroids. T. solium tapeworms were recovered from the intestine of golden hamsters that had been orally infected with cysticerci. The worms were cultured in the presence of tritiated progesterone or androstenedione. At the end of the experiments the culture media were analyzed by thin layer chromatography. The experiments described here showed that small amounts of testosterone were synthesized from (3)H-progesterone by complete or segmented tapeworms whereas the incubation of segmented tapeworms with (3)H-androstenedione, instead of (3)H-progesterone, improved their capacity to synthesize testosterone. In addition, the incubation of the parasites with (3)H-progesterone yielded corticosteroids, mainly deoxicorticosterone (DOC) and 11-deoxicortisol. In summary, the results described here, demonstrate that T. solium tapeworms synthesize corticosteroid and sex steroid like metabolites. The capacity of T. solium tapeworms to synthesize steroid hormones may contribute to the physiological functions of the parasite and also to their interaction with the host.

In vitro effect of sodium fluoride on antioxidative enzymes and apoptosis during murine odontogenesis.

Excessive fluoride ingestion has been identified as a risk factor for fluorosis and oxidative stress. The oxidative stress results from the loss of equilibrium between oxidative and antioxidative mechanisms that can produce kinase activation, mitochondrial disturbance and DNA fragmentation, resulting in apoptosis. Actually many people are exposed to no-adverted fluoride consumption in acute or chronic way. The aim of this study was to determine the effect of sodium fluoride on first molar germ in relation to its effect on antioxidative enzymes immunoexpression and apoptosis. Thirty first molar germs from 1-day-old Balb/c mice were cultured for 24 h with sodium fluoride (0 mM, 1 mM and 5 mM). Immunoexpression determination of CuZnSod, MnSod, catalase, Bax, Bid, caspase 8, caspase 9, caspase 3 and TUNEL assay were performed. Cellular disorganization in ameloblast and odontoblast-papilla zones was observed. CuZnSod and MnSod immunoexpression decrease in experimental groups. Caspase 8, caspase 3, Bax, Bid increase expression and more TUNEL positive cells in both experimental groups than control, suggest that apoptosis induced by fluoride is related to oxidative stress due to reduction of the enzymatic antioxidant.

Zoonosis por helmintos en mamíferos de morelia, Michoacán, República Mexicana / Helminthes in rats and other mammiferous

Mediante captura y examen de pequeños mamíferos de la Ciudad de Morelia, Michoaan, República Mexicana, se encontraron parasitados por diversos helmintos, céstodos y nemátodos, así como por protozoos de los que también afectan al hombre. Los principales mamíferos capturados fueron Rattus norvegicus y Rattus rattus, encontrándose parasitados principalmente por Trichinella spiralis 60 por ciento, Hymenolepis diminuta 45 por ciento, e Hymenolepis nana 1.3 por ciento. Se señala la importancia que tienen este tipo de estudios, para determinar los mamíferos que funcionan como reservorios de zoonosis y fuente de infección para el hombre en la Ciudad de Morelia, Michoacán, República Mexicana y de otras localidades del país

[Frequency of Toxocara cati eggs in domestic cats in Mexico City and the State of Mexico]. / Frecuencia de hallazgo de huevos de Toxocara cati en gatos domésticos de la Ciudad de México y el Estado de México.

Toxocariosis is a zoonosis which has been widely studied in dogs. However, not much is known about this parasitosis in cats. The aim of the present work was to determine the frequency of Toxocara cati in domestic cats in Mexico City and the State of Mexico. Feces of 660 domestic cats were studied by the Faust concentration-floating test; 401 samples were from cats living in Mexico City of which 308 lived in houses and 93 in apartments; 231 were from urban areas of the State of Mexico and 28 from a rural area of the same state. The total frequency of T. cati eggs obtained from domestic cats in Mexico City was 42.9%; in cats living in apartments it was 18.3% and in cats living in houses it was 50.3%. In domestic cats from the State of Mexico, T. cati frequency was 36.4% in the urban and 21.4% in the rural areas. We consider that toxocariosis frequency observed at the two studied sites is high and that the need to prevent dissemination of the infectious forms of T. cati is urgent, as is the necessity of informing the population of the risk of living with T. cati parasited animals and of the anatomopathological alterations caused by T. cati in man.

[Infection by Toxoplasma gondii in children with infantile cerebral palsy]. / Infección por Toxoplasma gondii en niños con parálisis cerebral infantil.

An analytic relationship between positivity of the indirect immunofluorescent test (IIFT) for toxoplasmosis and clinical findings in a population of 328 children with cerebral infantile palsy (CIP) was performed. Children were distributed by age in one of four groups: I (0-2 years); II (3-6 years); III (7-12 years) and IV (13-18 years). One control group of 168 children with no PCI clinical findings was included. 125 sera were positive at 1:64 dilutions. The study of the binomial mother-child of 40 cases rendered 26 mothers with significant titer values. The majority of positive mothers to IIFT correlated with the youngest children (Groups I, II and III), mainly with group I (70.0%), which showed the highest titer ranges. Correlation between positive IIFT and clinical features was as high as 100.0%.

[Frequency of vaginal trichomoniasis and candidiasis and its relation to the clinical profile]. / Frecuencia de tricomoniasis y candidiasis vaginal y su relación con el cuadro clínico.

Eight hundred samples of vaginal swabs were taken from women with active sexual life attending the Cervicouterine Cancer Opportune Detection Service at the Familial Medicine Unit No. 18 of the National Institute of Social Security, to study the incidence and prevalence of vaginal trichomoniasis, the presence of yeasts of the genus Candida and their relationships with clinical features of vulvovaginitis. Identification of parasites was made by means of direct examination with light microscope; 14.39 per cent of candida vulvovaginitis against 3.13 per cent of trichomoniasis was found; in only five cases the two parasites were associated. Leukorrhea and vaginal pruritus were the major symptoms found and the most affected anatomical regions were vaginal walls in trichomoniasis and cervix in candidiasis. Although vaginal trichomoniasis is a worldwide distributed parasitosis, its frequency is very variable, not so vaginal candidiasis, which is more frequent.