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The major diagnostic antigens of Histoplasma capsulatum var. capsulatum are the H and M antigens, pluripotent glycoproteins that elicit both humoral and T-cell-mediated immune responses. The gene encoding the M antigen has previously been sequenced, and its sequence has significant overall homology to those of the genes for fungal catalases. Regions of the M-antigen gene with little or no homology were used to design four oligonucleotide sequences for application in the PCR detection and identification of H. capsulatum var. capsulatum. The PCR correctly identified the 31 H. capsulatum var. capsulatum strains isolated from human, animal, and soil specimens and 1 H. capsulatum var. duboisii isolate. PCR products of 111 and 279 bp were amplified with primers Msp1F-Msp1R and Msp2F-Msp2R, respectively. No amplification product was obtained from DNA extracted from an H. capsulatum var. farciminosum isolate. The specificity of the PCR with the M-antigen-derived primers was confirmed by the total absence of amplification products when genomic DNA from Paracoccidioides brasiliensis, Candida spp., Sporothrix schenckii, Cryptococcus neoformans, Blastomyces dermatitidis, Coccidioides immitis, Aspergillus niger, and Aspergillus fumigatus were applied in the reaction. This rapid, sensitive, and specific assay provides a way to identify typical and atypical isolates of H. capsulatum var. capsulatum.Histoplasmosis, a systemic fungal disease caused by Histoplasma capsulatum var. capsulatum (15), is an important health problem worldwide. Although the majority of cases present as a mild to moderate flu-like disease requiring only supportive therapy, approximately 5% of patients develop a more serious pulmonary and extrapulmonary disease that can be life-threatening if diagnosis is delayed or if treatment is not initiated rapidly. Histoplasmosis is most prevalent in the midwestern states of the United States (27-30), although smaller regions of endemicity are scattered throughout most of Latin America (17,22,24). The disease is one of the most common systemic mycoses in Brazil, where epidemiological surveys carried out by use of the histoplasmin skin test indicate that this mycosis is endemic in all areas surveyed (9). These data suggest that the numbers of cases of histoplasmosis in Brazil may be underestimated and that the areas of endemicity are more widespread than previously thought.The diagnosis of histoplasmosis is based on the results of clinical evaluation, culture of the organism, and various laboratory tests. Isolation and culture of H. capsulatum var. capsulatum provide a definitive diagnosis (15, 30), although complement fixation and precipitin tests that detect antibodies against the major serodiagnostic marker (the M antigen) play a significant role in the identification of infection (10,11,18,(33)(34)(35)(36).The Histoplasma urine antigen test is also useful, particularly in cases of disseminated disease (31). However, serodiagnostic methods have limitations associated with false positivity, which arises from the pr...

Recurrent urinary tract infections (UTIs) are observed in 30-50% of children after the first UTI. Of these, approximately 90% occur within 3 months of the initial episode. The basic aim of antibiotic prophylaxis in children with malformative uropathy and/or recurrent UTIs, is to reduce the frequency of UTIs. The bacteria most frequently responsible for UTI are gram-negative organisms, with Escherichia coli accounting for 80% of urinary tract pathogens. In children with recurrent UTIs and in those treated with antibiotic prophylaxis there is a greater incidence of UTI due to Proteus spp., Klebsiella spp. and Enterobacter spp., whereas Pseudomonas spp., Serratia spp. and Candida spp. are more frequent in children with urogenital abnormalities and/or undergoing invasive instrumental investigations. Several factors are involved in the pathogenesis of UTI, the main ones being circumcision, periurethral flora, micturition disorders, bowel disorders, local factors and hygienic measures. Several factors facilitate UTI relapse: malformative uropathies, particularly of the obstructive type; vesico-ureteric reflux (VUR); previous repeated episodes of cystitis and/or pyelonephritis (3 or more episodes a year), even in the absence of urinary tract abnormalities; a frequently catheterized neurogenic bladder; kidney transplant. The precise mechanism of action of low-dose antibiotics is not yet fully known. The characteristics of the ideal prophylactic agent are presented in this review, as well as indications, dosages, side effects, clinical data of all molecules. While inappropriate use of antibiotic prophylaxis encourages the emergence of microbial resistance, its proper use may be of great value in clinical practice, by reducing the frequency and clinical expression of UTIs and, in some cases such as VUR, significantly helping to resolve the underlying pathology.

An ELISA was developed and evaluated as a method for detecting antibodies against glycosylated and deglycosylated histoplasmin (HMIN). Sera from patients with histoplasmosis, paracoccidioidomycosis, sporotrichosis, coccidioidomycosis, aspergillosis, cryptococcosis and healthy donors were tested by ELISA against purified, deglycosylated histoplasmin (ptHMIN) and compared with purified, native (i.e. glycosylated) histoplasmin (pHMIN). Although cross-reactivity was not abolished when ptHMIN was used in the test, it was reduced (pHMIN ELISA 93 % versus ptHMIN ELISA 96 %). However, there were statistically significant differences between the sensitivities of these two methods for the detection of antibodies (pHMIN ELISA 57 % versus ptHMIN ELISA 92 %; P , 0 . 001) and between the efficiency of the methods (pHMIN ELISA 83 % versus ptHMIN ELISA 95 %; P , 0 . 001). These parameters compare better than previously published data relating to the use of treated HMIN in diagnostic ELISAs. Some of the reactivities of serum samples were compared by immunoblotting using deglycosylated HMIN and by immunodiffusion using the crude antigen. The results demonstrated that cross-reactions with heterologous sera in both ELISAs could also be observed in immunoblotting and arose from shared protein epitopes. These data suggest that ELISA using deglycosylated HMIN is a very sensitive diagnostic method and, by using commercially available antigen, it can be easily standardized and performed faster than previous Western blot-based tests using the same antigen. It provides a useful adjunct to existing methods of diagnosis that could be applied even in situations where laboratory facilities were relatively limited. INTRODUCTIONHistoplasmosis is a systemic fungal disease caused by Histoplasma capsulatum. The significance of histoplasmosis results from its worldwide distribution (Rios-Fabra et al., 1994;Wheat, 2001), its ability to mimic other serious disease entities (Goodwin et al., 1980;McKinsey et al., 1997) and its propensity to cause serious disseminated infection in immunocompromised patients (Bradsher, 1996;Goodwin et al., 1980;Wheat, 1996;Wheat & Kauffman, 2003).Definitive diagnosis has typically relied either on direct visualization of the organism in tissue and/or the isolation of the causative organism, which is time-consuming and lacking in sensitivity (Bullock, 1995;Kwon-Chung & Bennet, 1992;Wheat, 2001). The detection of patients' antibody responses offers a more rapid alternative to microbiological means of diagnosis, and the detection of host anti-H. capsulatum antibodies by immunodiffusion (ID) and complement fixation (CF) tests is often used (Bullock, 1995;Kaufman et al., 1997). Both the yeast and mycelial phases of the fungus produce a number of exoantigens in culture, the most important and characteristic being the H and M antigens. These two antigens are the primary immunoreactive constituents of histoplasmin (HMIN), the standard diagnostic reagent used in ID and CF for many years (Standard & Kaufman, 1976). However, it was...