Modulatory activity of antioxidants against the toxicity of Rifampicin in vivo

The World Health Organization (WHO) has shown concern about the burden of tuberculosis in the developing countries. Even though rifampicin is an effective drug in the management of tuberculosis, it has been documented to have some toxic effects in humans. Therefore, this study intends to investigate the modulatory effect of vitamins C and E on the hepatotoxicity, sperm quality and brain toxicity of Rifampicin. Forty Wistar albino rats were used, 10 animals per group. Group 1 animals received 0.3 mL of distilled water, the Group 2 animals received the therapeutic dose of rifampicin, Group 3 animals received therapeutic doses of rifampicin plus vitamin E, while Group 4 received therapeutic doses of rifampicin and vitamin C. The administration was performed orally during three months; the animals were sacrificed by cervical dislocation at the end of that period. Blood samples were collected and liver function and lipid profile was analyzed using fully automated clinical chemistry device. The liver, brain and reproductive organs underwent histopathological examination. Sperm samples were collected from the epididymis to achieve count and motility and morphological analysis. Results showed rifampicin alone to raise (p < 0.05) liver function enzymes (Aspartate amino transferase [AST], Serum alanine amino transferase [ALT] and Total Bilirubin) when compared with controls. While the vitamin E treated group showed remarkable protection, the vitamin C treated group showed questionable protection against the rifampicin induced liver damage. Sperm count results showed an important (p < 0.05) increase in the sperm quality in vitamin E and C treated groups. However, the vitamin E plus Rifampicin treated group showed increased lipid peroxidation. The histopathological findings revealed structural damages by rifampicin in liver, brain and epididymis while some remarkable architectural integrity was observed in the antioxidant-treated groups. It can be concluded that vitamin E or C improved sperm quality and protected against the brain damage caused by rifampicin. Moreover, vitamin E demonstrated remarkable hepatoprotection against rifampicin induced damage while vitamin C shows a questionable hepatoprotection.

Echinococcus granulosus sensu lato GENOTYPES IN DOMESTIC LIVESTOCK AND HUMANS IN GOLESTAN PROVINCE, IRAN

Cystic echinococcosis (CE) is a globally parasitic zoonosis caused by larval stages of Echinococcus granulosus. This study investigated E. granulosus genotypes isolated from livestock and humans in the Golestan province, northern Iran, southeast of the Caspian sea, using partial sequencing data of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase 1 (nad1) mitochondrial genes. Seventy E. granulosus isolates were collected from animals in slaughterhouses: 18 isolates from sheep, 40 from cattle, nine from camels, two from buffaloes and one from a goat, along with four human isolates (formalin-fixed, paraffin-embedded tissues) from CE patients of provincial hospitals. All isolates were successfully analysed by PCR amplification and sequencing. The sequence analysis found four E. granulosus genotypes among the 74 CE isolates: G1 (78.3%), G2 (2.7%), G3 (15%) and G6 (4%). The G1-G3 complex genotype was found in all of the sheep, goat, cattle and buffalo isolates. Among the nine camel isolates, the frequency of G1-G3 and G6 genotypes were 66.7% and 33.3%, respectively. All four human CE isolates belonged to E. granulosus sensu stricto. This study reports the first occurrence of the G2 genotype in cattle from Iran and confirms the previously reported G3 genotype in camels in the same country.

Nested-PCR using MPB64 fragment improves the diagnosis of pleural and meningeal tuberculosis

Fluids in which Mycobacterium tuberculosis are seldom found, such as pleural and cerebrospinal liquids, are good candidates to be studied using PCR techniques. We detail our experience with a PCR assay applied to pleural and cerebrospinal fluids using the primer MPB64. Seventy three specimens were analyzed: 30 pleural fluids (PF), 26 pleural biopsies (PB) and 17 cerebrospinal fluids (CSF). The gold standard for the diagnosis of tuberculous meningitis was the positive culture for M. tuberculosis in CSF. Tuberculous pleural effusion was diagnosed when cultures of PF and/or PB were positive for M. tuberculosis, or the PB histology showed granulomas. Our results, compared to the gold standards employed, showed a sensitivity of 70%, specificity of 88%, positive predictive value of 82% and negative predictive value of 80%. The high specificity of the MPB64 fragment while still retaining a good sensitivity makes it very well suited for pleural and cerebrospinal tuberculosis diagnosis.

Impact of livestock on a mosquito community (Diptera: Culicidae) in a Brazilian tropical dry forest

AbstractINTRODUCTION: This study evaluated the effects of cattle removal on the Culicidae mosquito community structure in a tropical dry forest in Brazil.METHODS: Culicidae were collected during dry and wet seasons in cattle presence and absence between August 2008 and October 2010 and assessed using multivariate statistical models.RESULTS: Cattle removal did not significantly alter Culicidae species richness and abundance. However, alterations were noted in Culicidae community composition.CONCLUSIONS: This is the first study to evaluate the impact of cattle removal on Culicidae community structure in Brazil and demonstrates the importance of assessing ecological parameters such as community species composition.

Bile duct-duodenal fistula caused by AIDS/HIV-associated tuberculosis

Allthough infrequent, digestive fistulae in HIV/AIDS patients have been reported throughout the digestive tract from the esophagus to the anus, with predominance of esophageal fistulae. AIDS/HIV-associated opportunistic infections may invade the digestive system and lead to fistula formation. Tuberculosis is the most common infection associated with these esophageal fistulae. We report here one case of bile duct-duodenal fistula in a female AIDS patient with associated abdominal Mycobacterium tuberculosis infection compromising lymphnodes of the hepatic pedicle where the fistula was found. According to the reviewed literature, this is the third case of bile duct-duodenal fistula associated with abdominal tuberculosis in AIDS patient, and the first where both the fistula and the tuberculosis infection were diagnosed at laparotomy for acute abdomen. Whether the AIDS patient with abdominal pain needs or not a laparotomy to treat an infectious disease is often a difficult matter for the surgeon to decide, as most of the times appropriate medical treatment will bring more benefit.

Review on the Molecular Tools for the Understanding of the Epidemiology of Animal Trypanosomosis in West Africa

The epidemiology of animal trypanosomosis around Bobo-Dioulasso (Burkina Faso, West Africa) benefited a lot in the last years from the progress of molecular tools. The two most used molecular techniques were the polymerase chain reaction for the diagnosis of the disease in cattle and the characterization of the trypanosomes in the host and the vector on one hand, and the microsatellite DNA polymorphism in tsetse flies to study the intraspecific genetic variability of the vector on the other hand. The results obtained in the Sideradougou area during a recent two year survey with these techniques, associated with many other georeferenced informations concerning vector and cattle distribution, natural environment, landuse, ground occupation, livestock management, were combined in a Geographical Information System. This new approach of a complex pathogenic system led to a better evaluation of the risk of trypanosome transmission.

Inhibition of the polymerase chain reaction by sputum samples from tuberculosis patients after processing using a silica-guanidiniumthiocyanate DNA isolation procedure

With the objective to evaluate PCR-mediated detection of Mycobacterium tuberculosis DNA as a diagnostic procedure for diagnosis of tuberculosis in individuals attending ambulatory services in Primary Health Units of the City Tuberculosis Program in Rio de Janeiro, Brazil, their sputum samples were collected and treated with a DNA extraction procedure using silica-guanidiniumthiocyanate. This procedure has been described to be highly efficient for extraction of different kind of nucleic acids from bacteria and clinical samples. Upon comparing PCR results with the number of acid-fast bacilli, no direct relation was observed between the number of bacilli present in the sample and PCR positivity. Part of the processed samples was therefore spiked with pure DNA of M. tuberculosis and inhibition of the PCR reaction was verified in 22 out of 36 (61%) of the samples, demonstrating that the extraction procedure as originally described should not be used for PCR analysis of sputum samples.

The development of an enzyme-linked immunosorbent assay for Trypanosoma vivax antibodies and its use in epidemiological surveys

There are data indicating that the distribution of Trypanosoma vivax in the Brazilian territory is expanding with potential to reach other areas, where the vectors are present. The detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. For this reason, an enzyme-linked immunosorbent assay (Tv-ELISA-Ab) with crude antigen from one Brazilian isolate of T. vivax was developed and evaluated. The sensitivity and specificity were respectively 97.6 and 96.9%. In the evaluation of cross-reactions, three calves inoculated with T. evansi trypimastigotes blood forms showed optical densities (OD) under the cut-off during the whole experimental period, except one at 45 days post-inoculation. With relation to Babesia bovis, B. bigemina, and Anaplasma marginale, which are endemic hemoparasites in the studied area, the cross-reactions were shown to be 5.7, 5.3, and 1.1%, respectively. The first serological survey of Pantanal and state of Pará showed that T. vivax is widespread, although regions within both areas had significantly different prevalences. Therefore, this Tv-ELISA-Ab may be a more appropriate test for epidemiological studies in developing countries because the diagnostic laboratories in most countries may be able to perform an ELISA, which is not true for polymerase chain reaction.

Trypanosoma (Duttonella) vivax: its biology, epidemiology, pathogenesis, and introduction in the New World - a review

The biology, epidemiology, pathogenesis, diagnostic techniques, and history of the introduction of Trypanosoma (Duttonella) vivax in the New World are reviewed. The two main immunological responses of trypanosome-infected animals - antibody production and immunodepression - are discussed in the context of how these responses play a role in disease tolerance or susceptibility. Isolation and purification of T. vivax are briefly discussed. The recent reports of bovine trypanosomiasis diagnosed in cattle on farms located in the Pantanal region of the states of Mato Grosso do Sul and Mato Grosso, Brazil, are also discussed.

Rhodococcus equi isolation from sputum of patients with suspected tuberculosis

Rhodococcus equi has emerged as an opportunistic pathogen associated with pulmonary, invasive or systemic infections in immunocompromised patients. We report the identification of 51 R. equi isolates found in sputum samples of 546 individuals suspected to have pulmonary tuberculosis in two Public Health Hospital Units in Brazil. The epidemiology of R. equi infection as well as the phenotypic identification and drug susceptibility profile of isolates are described in this paper.

Interaction of Trichomonas vaginalis and Tritrichomonas foetus with keratin: an important role in parasite infection

Trichomonas vaginalis and Tritrichomonas foetus are human and bovine parasites, respectively, that provoke the sexually transmitted disease trichomoniasis. These extracellular parasites adhere to the host epithelial cell surface. Although mucinases and proteases have been described as important proteins for parasite adhesion to epithelial cells, no studies have examined the role of the keratin molecules that cornify the vaginal epithelium. Here, we investigated the interaction of T. vaginalis and T. foetus with human keratin in vitro; additionally, adherence assays were performed in cattle with T. foetus to elucidate whether trichomonads were able to interact with keratin in vivo. We demonstrated that both T. vaginalisand T. foetusinteracted directly with keratin. Additionally, the trichomonads ingested and digested keratin, shedding new light on the Trichomonas infection process.

Comparative evaluation of the microplate nitrate reductase assay and the rezasurin microtitre assay for the rapid detection of multidrug resistant Mycobacterium tuberculosis clinical isolates

The microplate nitrate reductase assay (MNRA) and the rezasurin microtitre assay (REMA) were used for the susceptibility testing of 73 clinical isolates and the results were compared with those that were obtained using the Bactec 460 TB and Bactec MGIT 960 systems. The REMA and the MNRA were performed in 96-well plates. For the REMA, the concentrations of isoniazid (INH) and rifampicin (RIF) ranged from 1.0-0.01 µg/mL and 2.0-0.03 µg/mL, respectively. For the MNRA, the INH concentration was between 1.0-0.03 µg/mL and the RIF concentration was between 2.0-0.06 µg/mL. For the MNRA, the sensitivity, specificity, positive predictive value, negative predictive value and INH/RIF agreement were 100/95.6, 97.6/100, 96.8/100, 100/98 and 98.6/98.6, respectively, and for the REMA, they were 100/91.3, 90.4/100, 88.5/100, 100/96.1 and 94.5/97.2, respectively. Our data suggest that these two rapid, low-cost methods may be inexpensive, alternative assays for the rapid detection of multidrug resistant tuberculosis in low-income countries.

Determination of fipronil in bovine plasma by solid-phase extraction and liquid chromatography with ultraviolet detection

A fast and efficient method has been developed and validated for the determination of fipronil in bovine plasma. Samples were subjected to solid-phase extraction (SPE) followed by reversed phase liquid chromatography (LC) separation, using acetonitrile/water (60:40 v/v) as the mobile phase with a flow rate of 1.0 mL/min and ultraviolet (UV) detection at 210 nm. Ethiprole was used as the internal standard (IS). The method was found to be linear over the range 5-500 ng/mL (r = 0.999). The limit of quantitation (LOQ) was validated at 5 ng/mL. The method was successfully applied to monitor plasma concentrations following subcutaneous administration of fipronil in cattle.

Crystal-associated cholangiopathy in sheep grazing Brachiaria decumbens containing the saponin protodioscin

An outbreak of hepatogenous photosensitization is reported in a flock of 28 sheep grazing Brachiaria decumbens in Mato Grosso do Sul State, Central-Western Brazil. Seven lambs and an adult sheep were affected and 6 of them died. Two surviving affected lambs and one lamb without clinical signs had increased serum values of gamma glutamyltransferase, bilirubin, and cholesterol. In two adult unaffected sheep those parameters were within normal values. An adult sheep submitted to necropsy presented moderate body condition, unilateral corneal opacity, drying of the muzzle, moderate jaundice, increased lobular pattern of the liver, and a distended gallbladder. Histological lesions were epithelial degeneration, necrosis, and hyperplasia of small bile ducts. Mild amounts of foamy macrophages were observed, mainly in the centroacinar zone. Diffuse swelling and vacuolation were observed in hepatocytes. Crystal negative images were found within bile ducts, foamy macrophages, and the lumen of some renal tubules. The heart showed multifocal areas of degeneration and necrosis of the muscle fibers. Pasture samples (Brachiaria decumbens) contained 2.36% of protodioscin. No Pithomyces chartarum spores were found in the pasture. Samples from a similar neighboring B. decumbens pasture grazed by cattle without photosensitization contained 1.63% of protodioscin isomers. Outbreaks of photosensitization caused by Brachiaria spp. are common in cattle in the Brazilian Cerrado (savanna) with about 51 million hectares of Brachiaria spp pastures. Sheep farming has been recently developed in this region, and the number of sheep is increasing significantly. Because sheep are more susceptible than cattle to lithogenic saponins, poisoning by Brachiaria should be an important limiting factor for the sheep industry.

Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells

Extracellular matrix plays an important role in chronic hepatic lesions and has been studied in experimental intoxication models. However in cattle, studies on chronic disease have focused on the hepatocellular damage and extracellular matrix (ECM) changes are usually overlooked. There are no specific studies on the hepatic ECM in either normal or chronically damaged bovine liver. Thus an experimental model of hepatic toxicity model using Senecio brasiliensis poisoned calves was designed. Senecio brasiliensis contains pyrrolizidine alkaloids which cause either acute or chronic progressive dose dependent liver damage. Five calves were orally fed with 0.38g of dry leaves of S. brasiliensis/kg/day for 24 days. Liver needle biopsy specimens were obtained every 15 days for 60 days. Clinical signs of digestive complications appeared at 3rd week. One calf died on 45th day and four were evaluated up to 60th day. Biopsy samples were processed for routine light microscopy, immuno-histochemistry and transmission electron microscopy. From 30th day on progressive liver damage characterized by hepatocellular ballooning, necrosis, apoptosis and megalocytosis, centrilobular, pericellular and portal fibrosis were seen by light microscopy. Quantitative and semi-quantitative measurements of hepatic ECM components were performed before and after the onset of lesions. Morphometric analysis of total collagen and elastic fiber system was conducted. Total collagen and I and III collagen types progressively increased in throughout the liver of affected calves. Changes in location, amount and disposition of the elastic fiber system were also observed. Then numbers of Kupffer cells were significantly increased at 30th day and total numbers of sinusoidal cells were significantly increased at 45th and 60th days. Liver damage was progressive and irreversible even after the exposure to the plant was discontinued. Severe fibrotic lesions occurred mainly in portal tracts, followed by veno-occlusive and pericellular fibrosis. Collagen types I and III s were present in every normal and damaged liver, with predominance of type I. In affected calves the increase of total collagen and elastic fibers system paralleled the number of total sinusoidal cells.