Phenotypical characterization and adhesin identification in Escherichia coli strains isolated from dogs with urinary tract infections

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Emended description of Yersinia massiliensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of four molecular typing Methodologies as tools for determining taxonomy relations and for identifying. species among Yersinia isolates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

TNF-alpha, H2O2 and NO response of peritoneal macrophages to Yersinia enterocolitica O : 3 derivatives

In this study, the effect of Yersinia derivatives on nitric oxide (NO), hydrogen peroxide (H2O2) and tumor necrosis factor-alpha (TNF-alpha) production by murine peritoneal macrophages was investigated. Addition of lipopolysaccharide (LPS) to the macrophage culture resulted in NO production that was dose dependent. on the other hand, bacterial cellular extract (CE) and Yersinia outer proteins (Yops) had no effect on NO production. The possible inhibitory effect of Yops on macrophage cultures stimulated with LPS was investigated. Yops partially inhibited NO production (67.4%) when compared with aminoguanidine. The effects of Yersinia derivatives on H2O2 production by macrophages were similar to those on NO production. LPS was the only derivative that stimulated H2O2 release in a dose-dependent manner. All Yersinia derivatives provoked the production of TNF-alpha, but LPS had the strongest effect, as observed for NO production. CE and Yops stimulated TNF-alpha production to a lesser extent than LPS. The results indicate the possibility that in vivo Yops may aid the evasion of the bacteria from the host defense mechanism by impairing the secretion of NO by macrophages. (C) 2003 Elsevier SAS. All rights reserved.

Yersinia enterocolitica O : 3 isolated from patients with or without reactive arthritis induces polyclonal activation of B cells and autoantibody production in vivo

The mechanisms by which arthritis-provoking pathogens such as Yersinia enterocolitica interact with the human immune system to produce inflammatory synovitis are not well known. One of the immunomodulating mechanisms used against these pathogens is the polyclonal activation of lymphocytes. In this study, we investigated the extent of the B-lymphocyte activation induced in mice by a strain of Y. enterocolitica O:3 (FCF 526) isolated from a patient with arthritis, and compared it with two other strains, a virulent one (FCF 397[+]) isolated from a patient without arthritis and its plasmidless isogenic pair (FCF397[-]). Also we investigated the production of autoantibodies in mice infected with these different strains. SPF Swiss mice were infected intravenously with a suspension of Y. enterocolitica . Spleen cells were taken on days 7, 14, 21 and 28 after infection and the number of cells secreting nonspecific and specific antibodies of IgG 1 , IgG 2a , IgG 2b , IgG 3 , IgM and IgA isotypes were determined by the ELISPOT technique. The presence of autoantibodies in mouse serum was investigated by the dot-blot assay. The pattern of infection of the three bacterial strains were almost the same. We observed a general increase in the number of nonspecific Ig-secreting cells with all three strains, and the greatest increases observed were in the IgG 2a and IgG 3 isotypes. Only a small fraction of the immunoglobulins detected were antibacterial, suggesting that the rest resulted from polyclonal B cell activation. The strain isolated from the patient with arthritis (FCF526) induced the greatest production of autoantibodies, coinciding with the period in which the greatest activation of nonspecific B lymphocytes was seen. There were no signs of arthritis or inflammation in the joints of the infected animals. Based on our results, we were unable to determine whether there is an association between the arthritogenic capability of Y. enterocolitica and polyclonal activation of B cells.

The hamster cheek pouch: an immunologically privileged site suitable to the study of granulomatous infections

A bolsa jugal do hamster (BJH) é uma invaginação da mucosa oral, caracterizada histologicamente como semelhante a pele. Nesse estudo nós descrevemos algumas de suas características anatômicas, histológicas e embriológicas e comentamos sobre sua propriedade como local imunologicamente privilegiado, considerando a ausência de drenagem linfática e o reduzido número de células de Langerhans. Apresentamos também os resultados obtidos quando da inoculação de micobacterias (BCG, Mycobacterium tuberculosis e Mycobacterium leprae) e do fungo Paracoccidioides brasiliensis na bolsa jugal. Comparada com as lesões provocadas em outras localizações e, à exceção do BCG, as lesões induzidas na bolsa são menores e de maior duração e, mesmo quando granulomatosas, incapazes de controlar a multiplicação do agente; nos casos em que houve o desenvolvimento da resposta imune, ele se fez tardiamente e foi acompanhado pela redução do número de parasitas nas lesões. Essas observações apontam a bolsa jugal do hamster como um local de escolha para o estudo sobre a participação da resposta imune no desenvolvimento e modulação das doenças infecciosas e dos granulomas.

Fungal infections of the mucous membrane

A clinical review of three potentially severe fungal diseases, which are characterized in many cases by mucosal involvement, is presented. They are paracoccidioidomycosis, histoplasmosis, and mucormycosis. Mucosal involvement for paracoccidioidomycosis and rhinocerebral mucormycosis is frequent. Thus, oral involvement may provide early clue for diagnosis. In paracoccidioidomycosis, the mucosal lesion classically shows superficial ulcers with granular appearance and hemorrhagic points, usually on lips, palate, and jugal mucosa. In mucormycosis, necrosis of the palate followed for purulent discharge is a hallmark of rhinocerebral disease. Treatment with amphotericin B desoxycholate or the new second-generation triazoles is highly efficacious.

Intestinal parasitic infections in HIV/AIDS patients: epidemiological, nutritional and immunological aspects

This study applied a socioeconomic questionnaire designed to evaluate the frequency of intestinal parasites and characterize epidemiological, nutritional, and immunological variables in 105 HIV/AIDS patients - with and without parasitic infections, attending the Day Hospital in Botucatu, UNESP, from 2007 to 2008. Body mass index was calculated and the following tests performed: parasitological stool examinations; eosinophil, IgE, CD4(+) T and CD8(+) T lymphocyte cell counts; albumin test; viral load measure; and TNF-alpha, IFN-gamma, IL-2, IL-5 and IL-10 cytokine levels. Results were positive for parasitic intestinal infections in 12.4% of individuals. Most patients had good socioeconomic conditions with basic sanitation, urban dwellings, treated water supply and sewage, good nutritional and immunological status and were undergoing HAART. Parasites were found at the following frequencies: Entamoeba - five patients (38.5%), Giardia lamblia-four (30.7%), Blastocystis hominis-three (23.0%), Endolimax nana-two (15.4%), and Ascaris lumbricoides - one (7.7%). There were no significant differences between the two groups for eosinophils, albumin, IgE, CD4(+) T and CD8(+) T lymphocytes, INF-gamma, IL-2, or IL-10. Most patients also showed undetectable viral load levels. Significant differences were found for TNF-alpha and IL-5. These results show the importance of new studies on immunodeficient individuals to increase understanding of such variables.

Usefulness of catheter tip culture in the diagnosis of neonatal infections

Objective: To determine the number of colony-forming units (CFU) that best correlates with catheter-related infections (CRI) in newborns.Methods: This was a prospective study of semiquantitative cultures of catheter tips obtained from newborns in the neonatal unit at Faculdade de Medicina de Botucatu, state of São Paulo, Brazil. The microorganisms isolated from catheter and peripheral blood cultures were identified and submitted to a drug susceptibility test. The optimal cutoff point was determined by the receiver operating characteristic (ROC) curve.Results: A total of 85 catheters obtained from 63 newborns were studied. Staphylococcus epidermidis was the predominant species in the catheters (75%). Eight of 11 (72.7%) CRI episodes were associated with coagulase-negative staphylococci, six of which were of the S. epidermidis type. ROC curve analysis indicated that the optimal cutoff point for the diagnosis of CRI was 122 CFU.Conclusions: The cutoff point of 122 CFU correlated best with the diagnosis of CRI in newborns.

Occurrence of Odontogenic Infections in Patients Treated in a Postgraduation Program on Maxillofacial Surgery and Traumatology

This study assessed the occurrence and characteristics of oral and maxillofacial infections in patients treated at a Brazilian oral and maxillofacial emergency service during a 7-year period. The clinical files of all patients treated at the Oral and Maxillofacial Surgery and Traumatology Service of the Aracatuba Dental School, São Paulo State University, Brazil, between 2002 and 2008 were reviewed. From a population of 3645 patients treated in this period, the study sample consisted of 93 subjects who presented odontogenic infections. Data referring to the patients' sex, age, medical history, and the etiology, diagnosis, complications, drug therapy/treatment, and evolution of the pathologic diseases were collected and analyzed using the Epi Info 2000 software. of these patients, 54 were men (58.1%) and 39 were women (41.9%). Most patients were in the 31- to 40-year-old (20.7%) and 21- to 30-year-old (19.6%) age groups. The most frequent etiology was pulp necrosis due to caries (80.6%). Regarding the treatment, antibiotics were administered to all patients, surgical drainage was done in 75 patients (82.4%), and 44 patients (47.3%) needed hospital admission. First-generation cephalosporin alone or combined with other drugs was the most prescribed antibiotic (n = 26) followed by penicillin G (n = 25). Most patients (n = 85, 91.4%) responded well to the treatment. Five cases had complications: 3 patients needed hospital readmission, 1 case progressed to descending mediastinitis, and 1 patient died. Odontogenic infections can be life-threatening and require hospital admission for adequate patient care. Complications from odontogenic infections, although rare, may be fatal if not properly managed.

The Potential of p38 MAPK Inhibitors to Modulate Periodontal Infections

Periodontal disease initiation and progression occurs as a consequence of the host immune inflammatory response to oral pathogens. The innate and acquired immune systems are critical for the proper immune response. LPS, an outer membrane constituent of periodontal pathogenic bacteria, stimulates the production of inflammatory cytokines IL-1 beta TNF alpha IL-6 and RANKL either directly or indirectly. In LPS-stimulated cells, the induction of cytokine expression requires activation of several signaling pathways including the p38 MAPK pathway. This review will discuss the significance of the p38 MAPK pathway in periodontal disease progression and the potential therapeutic consequences of pharmacological antagonism of this pathway in the treatment of periodontal diseases.

Immune response and performance of growing Santa Ines lambs to artificial Trichostrongylus colubriformis infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental infections with Paracoccidioides brasiliensis obtained from armadillos: comparison to clinical isolates

Paracoccidioides brasiliensis causes paracoccidioidomycosis (PCM) that is one of the most prevalent systemic human mycoses in Latin America. Armadillos show a high incidence of PCM infection and could, therefore, be a natural reservoir for this fungus. In this study were compared the virulence profiles of isolates obtained from nine-banded armadillos (Dasypus novemcinctus) (PbT1 and PbT4) and isolates from PCM patients (Pb265 and Bt83). Pathogenicity was evaluated by fungal load and analysis of colony morphology. Immunity against the fungus was tested by delayed type hypersensitivity test (DTH) and antibody quantification by ELISA. The higher virulence of PbT1 and PbT4 was suggested by higher fungal load in spleen and lungs. Armadillo isolates and Bt83 presented a cotton-like surface contrasting with the cerebriform appearance of Pb265. All isolates induced cellular and humoral immune responses in infected BALB/c mice. DTH reactions were similarly induced by the four isolates, however, a great variability was observed in specific antibody levels, being the highest ones induced by Bt83 and PbT4. The present work confirms that armadillos harbor P. brasiliensis, whose multiplication and induced immunity in experimentally infected mice are heterogeneous, resembling the behavior of isolates from human PCM. This study reinforces the possibility that armadillos play an important role in the biological cycle of this pathogen.

Experimental autoimmune encephalomyelitis evolution was not modified by multiple infections with Strongyloides venezuelensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efficacy of the nematode-trapping fungus Duddingtonia flagrans against infections by Haemonchus and Trichostrongylus species in lambs at pasture

The efficacy of the nematode-trapping fungus Duddingtonia flagrans against infections by trichostrongyle nematodes in sheep was assessed throughout 6 months. Twenty Ile de France lambs were divided into two groups (control and treated groups), which were kept in separate pastures. Animals of the treated group were fed with D. flagrans twice a week (Tuesdays and Fridays). Pellets were prepared with the fungus mycelia in liquid culture medium and contained approximately 20% fungus. They were mixed with the animals' diet at a concentration of 1 g pellet per 10 kg live weight. Faecal egg counts (FEC), packed cell volume (PCV), total serum protein and the animals' body weight were determined fortnightly from 7 October 2005 to 24 March 2006. Comparison of such parameters between groups showed no significant differences (P > 0.05), except on 10 February 2006, when the control group presented a higher mean FEC than the treated group (P < 0.05). Feeding sheep with pellets containing D. flagrans had no benefit to the prophylaxis of nematode infections under the experimental conditions used in the present study.