Mateus Matiuzzi da Costa

Atividade antimicrobiana “in vitro” de extrato alcóolico de própolis

O genero Candida sp . compreende 200 especies conhecidas, mas somente uma dezena de especies possui a faculdade de adaptar-se a temperatura de 37°C, podendo ser, ocasionalmente, patogenicas para o homem. Entre elas, estao: C. albicans, C. tropicalis, C. kefyr (pseudotropicalis),C. krusei, C. guilliermondii, C. parakrusei, C. zeylainoides, C.stellatoidea e C. brumpti i. A candidiase e a principal infeccao fungica oportunista do ser humano, causada por leveduras do genero Candida sp ., que fazem parte da microbiota endogena do corpo humano. Por isso, podem acometer hospedeiros sadios, mas a maioria das candidiases se desenvolve em individuos imuno comprometidos, como os pacientes infectados pelo HIV, os que receberam transplante de um orgao, os que fazem tratamento com citostaticos, corticoides e tratamento prolongado com antibacterianos de amplo espectro. Alem disso,o comprometimento de barreiras anatomicas secundariamente a queimadura ou procedimentos invasivos, comoo cateterismo, abrem portas para a invasao.

Caracterização epidemiológica, molecular e perfil de resistência aos antimicrobianos de Escherichia coli isoladas de criatórios suínos do sul do Brasil

Colibacillosis is an enteric disease with a major impact to the swine industry and is caused by enterotoxigenic strains of Escherichia coli. Forty clinical isolates from pigs with diarrhea and 13 environmental isolates were analysed regarding their genotypic profile, genetic relationship and antibiotic resistance. The most prevalent gene was Stb, identified in 50% of the isolates from clinical cases, and Sta and Lt were detected in 35% of them. Among the adesine factors investigated, F18 was found in 27.5% of the E. coli strains. The ERIC-PCR technique used for epidemiological characterization of the isolates did not show the expected discriminatory power. However, the test allowed separation of the isolates in groups, but did not evidence groups related to virulence factors. In the susceptibility test, the highest values for resistance were to tetracycline, in 88.6%. The index of multiple resistance to antimicrobials varied from 0 to 0.69.

Utilização de Saccharomyces cerevisiae como probiótico para tilápias-do-nilo durante o período de reversão sexual submetidas a um desafio sanitário

A 29-d experiment was carried out to evaluate the Saccharomyces cerevisiae (SC) as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion phase, under a sanitary challenge. Three hundred 2-d larvae averaging 8.9 ± 1.02 mg and 0.71 ± 0.09 cm were allotted to a completely randomized design with two treatments and six replicates in twelve 50 L-aquaria. Sanitary challenge consisted of a daily supply of 0.5 mL of fresh swine manure. Treatments consisted of a commercial diet for the sexual reversion of tilapia, with (TP) or without (TT) 0.1% of S. cerevisiae. The larvae were fed ad libitum five times a day. At the end of experiment, the fries were counted, measured and weighed. Two fries of each treatment were randomly chosen for gu removal and counting of the number of bacteria and total coliforms. No treatment effect on performance and survival was observed. Only the intestine of TP fries was colonized by SC. No significant differences were observed for bacteria and total coliforms per g of intestinal content and aquarium water. The use of Saccharomyces cerevisiae as probiotic in diets for Nile tilapia (Oreochromis niloticus) during the sexual reversion period resulted in intestine settling with no effect on performance and survival, in a system of culture with sanitary challenge.

Evaluation of PCR Based on Gene apxIVA Associated with 16S rDNA Sequencing for the Identification of Actinobacillus pleuropneumoniae and Related Species

The pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one the most important swine respiratory diseases. Biochemical and serological tests are widely applied for App diagnosis and characterization. However, in some isolates, conflicting results are found. The present work focus on the characterization of 29 isolates biochemically classified as A. pleuropneumoniae, collected from swine in herds with or without a clinical history of pleuropneumonia. Sixteen isolates were from healthy swine, initially classified as nonserotypable A. pleuropneumoniae; they displayed differences in the molecular characterization patterns of App (genes cpx and apxI, II, and III). Those bacteria that could not be serotyped were submitted to rDNA 16S sequencing. All 29 isolates were analyzed by PCR for the presence of the apxIVA gene. Thirteen isolates (45%) were confirmed to be A. pleuropneumoniae by PCR, nine being from diseased animals (31%) and four from healthy animals (14%) with conclusive serotyping. The rDNA 16S sequencing was used to classify the other 16 isolates in related species other than A. pleuropneumoniae, resulting in eleven A. minor, three A. porcinus, and two Pasteurella sp. Because of conflicting results between biochemical tests and rDNA 16S sequencing, the biochemical characterization was repeated, and the new results were in agreement with the rDNA 16S sequencing data. Biochemical characterization proved to be efficient for the majority of the A. pleuropneumoniae isolates. Nevertheless, conventional tests can render conflicting results, and other methodologies, such as amplification of A. pleuropneumoniae specific apxIVA gene and rDNA 16S sequencing, are very useful for improved classification. We also observed a great variety in rDNA 16S sequences from different A. minor isolates.

Virulence factors, antimicrobial resistance, and plasmid content of Escherichia coli isolated in swine commercial farms

Virulence factors and antimicrobial resistance patterns of Escherichia coli isolates were evaluated. A total of 80 E. coli isolates were evaluated, being 64 from clinical samples (intestinal content and fragments of organs from diarrheic piglets), seven from feces of clinically healthy piglets and sows, and nine environmental samples (five from facilities, two from feed, one from insect, and one from waste). Molecular characterization was performed by PCR detection of fimbriae and toxin genes and plasmid content determination. The isolates were also characterized according to their resistance or sensitivity to the following drugs: ampicillin, trimethoprim:sulfamethoxazole, tetracycline, amikacine, colistin, norfloxacin, florfenicol, enrofloxacin, cefalexin, trimethoprim, neomycin, chloramphenicol, and gentamicin. From 80 E. coli isolates, 53.8% were classified as enterotoxigenic E. coli (ETEC), 2.5% were shiga toxin-producing E. coli (STEC), and 43.8% showed a non specific pattern and were unclassified. One fecal isolate from non-diarrheic piglet was classified as ETEC by PCR. Clinical isolates showed resistance mainly for tetracycline and trimethoprim:sulfamethoxazole. Plasmidial DNA was observed in 70 isolates, being 78.5% of clinical isolates, 8.57% of non-diarrheic feces, and 12.8% of environment.

Virulence factors and antimicrobial resistance of escherichia coli isolated from urinary tract of swine in southern of Brazil

The present study determined the molecular and resistance patterns of E. coli isolates from urinary tract of swine in Southern of Brazil. Molecular characterization of urinary vesicle samples was performed by PCR detection of virulence factors from ETEC, STEC and UPEC. From a total of 82 E. coli isolates, 34 (38.63%) harbored one or more virulence factors. The frequency of virulence factors genes detected by PCR were: pap (10.97%), hlyA (10.97%), iha (9.75%), lt (8.53%), sta (7.31%) sfa (6.09%), f4 (4.87%), f5 (4.87%), stb (4.87%), f6 (1.21%) and f41 (1.21%). Isolates were resistant to penicillin (95.12%), lincomycin (93.9%), erythromycin (92.68%), tetracycline (90.24%), amoxicillin (82.92%), ampicillin (74.39%), josamycin (79.26%), norfloxacin (58.53%), enrofloxacin (57.31%), gentamicin (39.02%), neomycin (37.8%), apramycin (30.48%), colistine (30.48%) and cefalexin (6.09%). A number of 32 (39.02%) E. coli isolates harbored plasmids.

Elisa indireto na detecção de Salmonella spp. em lingüiça suína

The performance of an ELISA test based on a monoclonal antibody (MAb) specific to Salmonella enterica serovar Enteritidis was compared with standard culture method for detection of Salmonella spp. in 110 samples of swine fresh sausages. The prevalence was of 11.82%, according the standard method. Comparison of ELISA and the culture method revealed the sensitivity, specificity, and positive and negative predictive values of 100%, 98%, 87% and 100%, respectively. Results indicate that compared with standard culture method the ELISA test was effective in detection of Salmonella in swine sausages naturally contaminated.

Isolamento de Campylobacter jejuni em feto ovino abortado: relato de caso

Campylobacter jejuni was isolated from aborted ovine fetus at the end of gestation. Three abortion cases within a week and another fourth case one month later were observed. Immediately after the third case, one fetus was submitted to necropsy and samples from abomasal content were collected for bacteriological analysis. At necropsy, only post-mortem and autolytic lesions were observed. Under microaerophilic conditions, a pure bacterial growth was obtained and identified by morphological and tintorial characteristics as Campylobacter sp., being the isolate confirmed as C. jejuni, by phenotypic and molecular assays. This is an alert for the possibility of this pathogen cause abortion in ovine.

Pathogenicity of Rhodococcus equi in mice, isolated from environment, human and horse clinical samples

Rhodococcus equi is a facultative intracellular pathogen associated with bronchopneumonia, mesenteric lymphadenitis and enterocolitis in foals. Although R. equi is likely to be found in every horse-breeding farm, the clinical disease is unrecognized in most of them. Capsule components, equi factor, micolic acid and some products encoded by the large 85-90Kb plasmid were described as virulence factors. However, the pathogenesis of R. equi infections and the sensibility of foals are not completely understood. The aim of this study was evaluate the virulence of R. equi isolated from human, horses and environment for mices. Nine strains carrying the 85-90Kb plasmid isolated from foal clinical specimens, one from immunodeficient human patient and six plasmidless strains (four isolated from feces, one from pasture and one from immunodeficient human patient) were inoculated in cyclophosphamide immunossuppressed mice. The pathological changes and viability of R. equi cells in the liver of mice was verified after the 3rd, 6th an 10th day after inoculation for horse and environmental isolates and for R. equi isolates from human patients on the 1st, 3rd and 6th day. During the necropsy procedures, infiltrate of macrophages and pyogranulomatous lesions were detected after the sixth pos-inoculation day in the liver and spleen. In horse isolates, only plasmid positive strains were virulent, but in human isolates both strains (plasmid positive e plasmid negative) were virulent. Both groups of the immunossupressed mice inoculated with R. equi isolated from environment showed pathological changes. All R. equi strains were unable to kill non imunossuppressed mice.

Susceptibilidade antimicrobiana de Campylobacter fetus subsp. venerealis isolado de bovinos

Venereal campylobacteriosis is associated with infection of Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis. The etiological agent is transmitted by natural bull breeding or artificial insemination using contaminated semen. The present study aimed to determine the in vitro susceptibility of C. fetus subsp. venerealis isolates to antimicrobial drugs generally used in clinical and semen treatment. Reference strains of C. fetus subsp. fetus and C. fetus subsp. venerealis and 21 C. fetus isolates were tested. The susceptibility test was performed by using the modified Kirby-Bauer diffusion disc method. C. fetus subsp. fetus reference strain was resistant to lincomycin and penicillin. C. fetus subsp. venerealis was susceptible to all antimicrobial tested, with exception to C.C. KrewerDnalidixic acid. C. fetus subsp. venerealis samples were sensible to amikacin, ampicillin, cefalotin, streptomycin, gentamycin, penicillin and tetracycline. Drug resistance was observed on 42.86% of lincomycin, 4,76 % of enrofloxacin, and 100% to nalidixic acid. In addition 4.76% of the isolates showed intermediate susceptibility to enrofloxacin, neomycin, polimixin B and 9.52% to lincomycin. The susceptibility of C. fetus isolates to antimicrobial drugs commonly used in clinical and semen treatment was demonstrated.