Analysis of the SNARE Stx8 recycling reveals that the retromer-sorting motif has undergone evolutionary divergence.

Fsv1/Stx8 is a Schizosaccharomyces pombe protein similar to mammalian syntaxin 8. stx8Δ cells are sensitive to salts, and the prevacuolar endosome (PVE) is altered in stx8Δ cells. These defects depend on the SNARE domain, data that confirm the conserved function of syntaxin8 and Stx8 in vesicle fusion at the PVE. Stx8 localizes at the trans-Golgi network (TGN) and the prevacuolar endosome (PVE), and its recycling depends on the retromer component Vps35, and on the sorting nexins Vps5, Vps17, and Snx3. Several experimental approaches demonstrate that Stx8 is a cargo of the Snx3-retromer. Using extensive truncation and alanine scanning mutagenesis, we identified the Stx8 sorting signal. This signal is an IEMeaM sequence that is located in an unstructured protein region, must be distant from the transmembrane (TM) helix, and where the 133I, 134E, 135M, and 138M residues are all essential for recycling. This sorting motif is different from those described for most retromer cargoes, which include aromatic residues, and resembles the sorting motif of mammalian polycystin-2 (PC2). Comparison of Stx8 and PC2 motifs leads to an IEMxx(I/M) consensus. Computer-assisted screening for this and for a loose Ψ(E/D)ΨXXΨ motif (where Ψ is a hydrophobic residue with large aliphatic chain) shows that syntaxin 8 and PC2 homologues from other organisms bear variation of this motif. The phylogeny of the Stx8 sorting motifs from the Schizosaccharomyces species shows that their divergence is similar to that of the genus, showing that they have undergone evolutionary divergence. A preliminary analysis of the motifs in syntaxin 8 and PC2 sequences from various organisms suggests that they might have also undergone evolutionary divergence, what suggests that the presence of almost-identical motifs in Stx8 and PC2 might be a case of convergent evolution.

The ancient claudin Dni2 facilitates yeast cell fusion by compartmentalizing Dni1 into a membrane subdomain.

Dni1 and Dni2 facilitate cell fusion during mating. Here, we show that these proteins are interdependent for their localization in a plasma membrane subdomain, which we have termed the mating fusion domain. Dni1 compartmentation in the domain is required for cell fusion. The contribution of actin, sterol-dependent membrane organization, and Dni2 to this compartmentation was analysed, and the results showed that Dni2 plays the most relevant role in the process. In turn, the Dni2 exit from the endoplasmic reticulum depends on Dni1. These proteins share the presence of a cysteine motif in their first extracellular loop related to the claudin GLWxxC(8-10 aa)C signature motif. Structure-function analyses show that mutating each Dni1 conserved cysteine has mild effects, and that only simultaneous elimination of several cysteines leads to a mating defect. On the contrary, eliminating each single cysteine and the C-terminal tail in Dni2 abrogates Dni1 compartmentation and cell fusion. Sequence alignments show that claudin trans-membrane helixes bear small-XXX-small motifs at conserved positions. The fourth Dni2 trans-membrane helix tends to form homo-oligomers in Escherichia plasma membrane, and two concatenated small-XXX-small motifs are required for efficient oligomerization and for Dni2 export from the yeast endoplasmic reticulum. Together, our results strongly suggest that Dni2 is an ancient claudin that blocks Dni1 diffusion from the intercellular region where two plasma membranes are in close proximity, and that this function is required for Dni1 to facilitate cell fusion.

The AP-2 complex is required for proper temporal and spatial dynamics of endocytic patches in fission yeast.

In metazoans the AP-2 complex has a well-defined role in clathrin-mediated endocytosis. By contrast, its direct role in endocytosis in unicellular eukaryotes has been questioned. Here, we report co- immunoprecipitation between the fission yeast AP-2 component Apl3p and clathrin, as well as the genetic interactions between apl3Δ and clc1 and sla2Δ/end4Δ mutants. Furthermore, a double clc1 apl3Δ mutant was found to be defective in FM4-64 uptake. In an otherwise wild-type strain, apl3Δ cells exhibit altered dynamics of the endocytic sites, with a heterogeneous and extended lifetime of early and late markers at the patches. Additionally, around 50% of the endocytic patches exhibit abnormal spatial dynamics, with immobile patches and patches that bounce backwards to the cell surface, showing a pervasive effect of the absence of AP-2. These alterations in the endocytic machinery result in abnormal cell wall synthesis and morphogenesis. Our results complement those found in budding yeast and confirm that a direct role of AP-2 in endocytosis has been conserved throughout evolution.

The long life of an endocytic patch that misses AP-2.

Endocytosis is the process by which cells regulate extracellular fluid uptake and internalize molecules bound to their plasma membrane. This process requires the generation of protein-coated vesicles. In clathrin-mediated endocytosis (CME) the assembly polypeptide 2 (AP-2) adaptor facilitates rapid endocytosis of some plasma membrane receptors by mediating clathrin recruitment to the endocytic site and by connecting cargoes to the clathrin coat. While this adaptor is essential for early embryonic development in mammals, initial results suggested that it is dispensable for endocytosis in unicellular eukaryotes. The drastic effect of depleting AP-2 in metazoa and the mild effect of deleting AP-2 subunits in Saccharomyces cerevisiae have prevented a detailed analysis of the dynamics of endocytic patches in the absence of this adaptor. Using live-cell imaging of Schizosaccharomyces pombe endocytic sites we have shown that eliminating AP-2 perturbs the dynamics of endocytic patches beyond the moment of coat assembly. These perturbations affect the cell growth pattern and cell wall synthesis. Our results highlight the importance of using different model organisms to address the study of conserved aspects of CME.

The FN3 and BRCT motifs in the exomer component Chs5p define a conserved module that is necessary and sufficient for its function.

Chs5p is a component of the exomer, a coat complex required to transport the chitin synthase Chs3p from the trans-Golgi network to the plasma membrane. The Chs5p N-terminal region exhibits fibronectin type III (FN3) and BRCT domains. FN3 domains are present in proteins that mediate adhesion processes, whereas BRCT domains are involved in DNA repair. Several fungi--including Schizosaccharomyces pombe, which has no detectable amounts of chitin--have proteins similar to Chs5p. Here we show that the FN3 and BRCT motifs in Chs5p behave as a module that is necessary and sufficient for Chs5p localization and for cargo delivery. The N-terminal regions of S. cerevisiae Chs5p and S. pombe Cfr1p are interchangeable in terms of Golgi localization, but not in terms of exomer assembly, showing that the conserved function of this module is protein retention in this organelle and that the interaction between the exomer components is organism-specific.

Exomer Is Part of a Hub Where Polarized Secretion and Ionic Stress Connect.

Plasma membrane and membranous organelles contribute to the physiology of the Eukaryotic cell by participating in vesicle trafficking and the maintenance of ion homeostasis. Exomer is a protein complex that facilitates vesicle transport from the trans-Golgi network to the plasma membrane, and its absence leads to the retention of a set of selected cargoes in this organelle. However, this retention does not explain all phenotypes observed in exomer mutants. The Schizosaccharomyces pombe exomer is composed of Cfr1 and Bch1, and cfr1Δ and bch1Δ were sensitive to high concentrations of potassium salts but not sorbitol, which showed sensitivity to ionic but not osmotic stress. Additionally, the activity of the plasma membrane ATPase was higher in exomer mutants than in the wild-type, pointing to membrane hyperpolarization, which caused an increase in intracellular K+ content and mild sensitivity to Na+, Ca2+, and the aminoglycoside antibiotic hygromycin B. Moreover, in response to K+ shock, the intracellular Ca2+ level of cfr1Δ cells increased significantly more than in the wild-type, likely due to the larger Ca2+ spikes in the mutant. Microscopy analyses showed a defective endosomal morphology in the mutants. This was accompanied by an increase in the intracellular pools of the K+ exporting P-type ATPase Cta3 and the plasma membrane Transient Receptor Potential (TRP)-like Ca2+ channel Pkd2, which were partially diverted from the trans-Golgi network to the prevacuolar endosome. Despite this, most Cta3 and Pkd2 were delivered to the plasma membrane at the cell growing sites, showing that their transport from the trans-Golgi network to the cell surface occurred in the absence of exomer. Nevertheless, shortly after gene expression in the presence of KCl, the polarized distribution of Cta3 and Pkd2 in the plasma membrane was disturbed in the mutants. Finally, the use of fluorescent probes suggested that the distribution and dynamics of association of some lipids to the plasma membrane in the presence of KCl were altered in the mutants. Thus, exomer participation in the response to K+ stress was multifaceted. These results supported the notion that exomer plays a general role in protein sorting at the trans-Golgi network and in polarized secretion, which is not always related to a function as a selective cargo adaptor.

The tetraspan protein Dni1p is required for correct membrane organization and cell wall remodelling during mating in Schizosaccharomyces pombe.

In fungi, success of mating requires that both cells agglutinate, modify their extracellular envelopes, and fuse their plasma membranes and nuclei to produce a zygote. Here we studied the role of the Schizosaccharomyces pombe Dni1 protein in the cell fusion step of mating. Dni1p is a tetraspan protein bearing a conserved cystein motif similar to that present in fungal claudin-related proteins. Dni1p expression is induced during mating and Dni1p concentrates as discrete patches at the cell-cell contact area and along the mating bridge. Proper Dni1p localization depends on Fus1p, actin and integrity of lipid rafts. In dni1Delta mutants, cell differentiation and agglutination are as efficient as in the wild-type strain, but cell fusion is significantly reduced at temperatures above 25 degrees C. We found that the defect in cell fusion was not associated with an altered cytoskeleton, with an abnormal distribution of Fus1p, or with a defect in calcium accumulation, but with a severe disorganization of the plasma membrane and cell wall at the area of cell-cell contact. These results show that Dni1p plays a relevant role in co-ordinating membrane organization and cell wall remodelling during mating, a function that has not been described for other proteins in the fission yeast.

The Schizosaccharomyces pombe Map4 adhesin is a glycoprotein that can be extracted from the cell wall with alkali but not with beta-glucanases and requires the C-terminal DIPSY domain for function.

SUMMARY: In fungi, cell adhesion is required for flocculation, mating and virulence, and it is mediated by covalently bound cell wall proteins termed adhesins. Map4, an adhesin required for mating in Schizosaccharomyces pombe, is N-glycosylated and O-glycosylated, and is an endogenous substrate for the mannosyl transferase Oma4p. Map4 has a modular structure with an N-terminal signal peptide, a serine and threonine (S/T)-rich domain that includes nine repeats of 36 amino acids (rich in serine and threonine residues, but lacking glutamines), and a C-terminal DIPSY domain with no glycosylphosphatidyl inositol (GPI)-anchor signal. Map4 can be extracted from cell walls with SDS/mercaptoethanol sample buffer or with mild alkali solutions. After extensive extraction with hot sample buffer, no more protein can be released by beta-glucanases or alkali. Additionally, none of the cysteine residues of the protein is required for its retention at the cell wall. These results show that Map4 is not directly bound to beta-glucans and point to the existence of alkali- and SDS/mercaptoethanol-sensitive linkages between cell wall proteins. The N-terminal S/T-rich regions are required for cell wall attachment, but the C-terminal DIPSY domain is required for agglutination and mating in liquid and solid media.

CAL1, a gene required for activity of chitin synthase 3 in Saccharomyces cerevisiae.

The CAL1 gene was cloned by complementation of the defect in Calcofluor-resistant calR1 mutants of Saccharomyces cerevisiae. Transformation of the mutants with a plasmid carrying the appropriate insert restored Calcofluor sensitivity, wild-type chitin levels and normal spore maturation. Southern blots using the DNA fragment as a probe showed hybridization to a single locus. Allelic tests indicated that the cloned gene corresponded to the calR1 locus. The DNA insert contains a single open-reading frame encoding a protein of 1,099 amino acids with a molecular mass of 124 kD. The predicted amino acid sequence shows several regions of homology with those of chitin synthases 1 and 2 from S. cerevisiae and chitin synthase 1 from Candida albicans. calR1 mutants have been found to be defective in chitin synthase 3, a trypsin-independent synthase. Transformation of the mutants with a plasmid carrying CAL1 restored chitin synthase 3 activity; however, overexpression of the enzyme was not achieved even with a high copy number plasmid. Since Calcofluor-resistance mutations different from calR1 also result in reduced levels of chitin synthase 3, it is postulated that the products of some of these CAL genes may be limiting for expression of the enzymatic activity. Disruption of the CAL1 gene was not lethal, indicating that chitin synthase 3 is not an essential enzyme for S. cerevisiae.

The function of chitin synthases 2 and 3 in the Saccharomyces cerevisiae cell cycle.

The morphology of three Saccharomyces cerevisiae strains, all lacking chitin synthase 1 (Chs1) and two of them deficient in either Chs3 (calR1 mutation) or Chs2 was observed by light and electron microscopy. Cells deficient in Chs2 showed clumpy growth and aberrant shape and size. Their septa were very thick; the primary septum was absent. Staining with WGA-gold complexes revealed a diffuse distribution of chitin in the septum, whereas chitin was normally located at the neck between mother cell and bud and in the wall of mother cells. Strains deficient in Chs3 exhibited minor abnormalities in budding pattern and shape. Their septa were thin and trilaminar. Staining for chitin revealed a thin line of the polysaccharide along the primary septum; no chitin was present elsewhere in the wall. Therefore, Chs2 is specific for primary septum formation, whereas Chs3 is responsible for chitin in the ring at bud emergence and in the cell wall. Chs3 is also required for chitin synthesized in the presence of alpha-pheromone or deposited in the cell wall of cdc mutants at nonpermissive temperature, and for chitosan in spore walls. Genetic evidence indicated that a mutant lacking all three chitin synthases was inviable; this was confirmed by constructing a triple mutant rescued by a plasmid carrying a CHS2 gene under control of a GAL1 promoter. Transfer of the mutant from galactose to glucose resulted in cell division arrest followed by cell death. We conclude that some chitin synthesis is essential for viability of yeast cells.

Rapid degradation of the G1 cyclin Cln2 induced by CDK-dependent phosphorylation.

Cyclins regulate the major cell cycle transitions in eukaryotes through association with cyclin-dependent protein kinases (CDKs). In yeast, G1 cyclins are essential, rate-limiting activators of cell cycle initiation. G1-specific accumulation of one G1 cyclin, Cln2, results from periodic gene expression coupled with rapid protein turnover. Site-directed mutagenesis of CLN2 revealed that its phosphorylation provides a signal that promotes rapid degradation. Cln2 phosphorylation is dependent on the Cdc28 protein kinase, the CDK that it activates. These findings suggest that Cln2 is rendered self-limiting by virtue of its ability to activate its cognate CDK subunit.

Ent3 and GGA adaptors facilitate diverse anterograde and retrograde trafficking events to and from the prevacuolar endosome.

Carboxypeptidases Y (Cpy1) and S (Cps1), the receptor Vps10, and the ATPase subunit Vph1 follow the carboxypeptidase Y (CPY) pathway from the trans-Golgi network (TGN) to the prevacuolar endosome (PVE). Using Schizosaccharomyces pombe quantitative live-cell imaging, biochemical and genetic analyses, we extended the previous knowledge and showed that collaboration between Gga22, the dominant Golgi-localized Gamma-ear-containing ARF-binding (GGA) protein, and Gga21, and between Gga22 and the endosomal epsin Ent3, was required for efficient: i) Vps10 anterograde trafficking from the TGN to the PVE; ii) Vps10 retrograde trafficking from the PVE to the TGN; iii) Cps1 exit from the TGN, and its sorting in the PVE en route to the vacuole; and iv) Syb1/Snc1 recycling to the plasma membrane through the PVE. Therefore, monomeric clathrin adaptors facilitated the trafficking of Vps10 in both directions of the CPY pathway, and facilitated trafficking events of Cps1 in different organelles. By contrast, they were dispensable for Vph1 trafficking. Thus, these adaptors regulated the traffic of some, but not all, of the cargo of the CPY pathway, and regulated the traffic of cargoes that do not follow this pathway. Additionally, this collaboration was required for PVE organization and efficient growth under stress.

Human Mycobacterium bovis infection in Castile and León (Spain), 2006-2015. / Tuberculosis por Mycobacterium bovis en la población de Castilla y León (España), 2006-2015.

INTRODUCTION: The annual incidence of tuberculosis (TB) from Mycobacterium bovis in humans has considerably declined in industrialised countries since the early twentieth century. The objective of this study was to determine the epidemiological, clinical and microbiological characteristics of patients with this illness in Castile and León (CyL). METHODS: Retrospective study of all M. bovis TB cases in CyL over a 10-year period, comparing the risk factors, the epidemiology and the clinical course between pulmonary (PTB) and extrapulmonary TB (EPTB). RESULTS: 75 cases of TB were due to M. bovis: 45 PTB and 31 EPTB. The annual incidence of TB due to M. bovis was 0.3 cases per 100,000. It remained stable between the first and second five-year period (0.27 vs. 0.33, p=0.656). However, the overall incidence of TB fell in both five-year periods (13.58 vs. 10.71, p<0.0001). The mean age was 66.2+21.3 years, mainly men (63%) and Spanish patients (92%). PTB was significantly more frequent in men, aged over 66 years, with immunosuppressive conditions or who were smokers. Mortality was 9%, associated with higher age, immunosuppression or treatment different from that recommended by the WHO. CONCLUSIONS: The incidence of M. bovis TB in CyL was higher than that for Spain and for other European countries, and remained stable despite the decreased the TB due to MTC. It affected mostly Spanish-born patients who lived in rural areas and with a high mean age.

[Family impact of rotavirus gastroenteritis in children under two years]. / Impacto familiar de la gastroenteritis por rotavirus en menores de dos años.

INTRODUCTION: Acute gastroenteritis (AGE) in infants has a significant impact on the quality of life of their parents. MATERIAL AND METHODS: Cross-sectional study on the sociological family impact related to rotavirus AGE in children under 2 years. The study was carried out in 25 hospitals and 5 primary care centres in Spain. Sociodemographic, epidemiological and clinical data were recorded, as well as the symptomatology of AGE and its severity measured by the Clark scale. Stool samples were tested to determine rotavirus positive (RV+) or negative (RV-). The parents were asked to complete a a family impact questionnaire. RESULTS: Stool specimens were tested in 1087 AGE cases (584 RV+ vs 503 RV-). The 99.5 % of parents whose children were RV+ reported more worries vs. the 97.7 % of RV-, and RV+ had a higher importance score (p < 0.05). A higher percentage of RV+ parents and those with a high importance score reported more time dedicated to dehydration treatment (p < 0.05). The 82.5 % vs. 73.9 % had disruption of their household tasks, with more importance scores (p < 0.05). RV+ had a higher percentage and importance score than RV- ones in all aspects of their child's AGE symptoms, except loss of appetite. CONCLUSION: AGE produces important dysfunctional experiences in daily family life. According to parental perceptions, RV+ produces greater worries and dysfunctions in child behaviour.

Lady Windermere syndrome in Castile and León. / Síndrome de Lady Windermere en Castilla y León.

INTRODUCTION: Lady Windermere syndrome (LWS) is a pulmonary disease caused by Mycobacterium avium complex (MAC). The objective of this study is to ascertain its frequency and characteristics in the northern area of the autonomous community of Castile and León. METHODS: A retrospective study of patients with MAC isolates in respiratory samples from five public hospitals in the autonomous community over a six-year period, following the ATS/IDSA criteria. The MAC strains were identified by GenoType Mycobacterium reverse hybridisation probes or PCR-RFLP analysis of the hsp65 gene. RESULTS: Of 183 cases of MAC identified, only five women (2.7%) aged 68.8±10.7years met LWS criteria. In three cases, MAC was isolated jointly and intermittently with other pathogens. Only one patient was treated according to ATS/IDSA criteria. DISCUSSION: LWS remains underestimated, with affected patients representing a significant burden on healthcare resources over long periods of time. As a result, greater microbiological and therapeutic knowledge of the syndrome is needed.

Contribution of microbiology in the diagnosis of tuberculosis in Castile and León (Spain): Findings of the GRUMICALE 2013 study. / Contribución de la microbiología al diagnóstico de la tuberculosis en Castilla y León: conclusiones del estudio GRUMICALE 2013.

INTRODUCTION AND OBJECTIVES: A retrospective study was conducted by collecting microbiological tuberculosis (TB) data in Castile and León during the year 2013 in order to determine the incidence and distribution of TB, and resistance to the tuberculostatic drug, and compare them with the epidemiological data provided by the Department of Epidemiological Surveillance (SIVE). MATERIAL AND METHODS: Microbiologists of the 14 hospitals of the Castile and León public health network (GRUMICALE) collected epidemiological, microbiological, and management data from the Microbiology laboratories in the community during the year 2013. A single isolate of Mycobacterium tuberculosis complex (MTC) per patient was considered. RESULTS: The study included a total of 270 MTC isolates (an incidence rate of 11.63 cases/100,000 inhab./year). A total of 288 cases of TB (11.43 cases/100,000 inhab. year) were recovered using epidemiological data, which included 243 confirmed, 29 suspected, and 16 as probable cases. Pulmonary TB was predominant, followed a long way off by the pleural TB and the remaining locations. A total of 27,620 samples were processed for mycobacterial detection. Mycobacterial growth was observed in 3.46% of automated fluid cultures, and 50.37% were positive by direct staining of the smear. Resistance to one tuberculostatic drug, mostly to isoniazid, was observed in 16 (5.92%) isolates of Mycobacterium tuberculosis (MT). The province with greater incidence and number of isolates was León (24.23 cases/100,000 inhab./year), with the highest being observed in El Bierzo health area (30.46 cases/100,000 inhab./year). CONCLUSIONS: An adequate collection of microbiological information is essential to determine the epidemiology of TB in our region.

CHS5, a gene involved in chitin synthesis and mating in Saccharomyces cerevisiae.

The CHS5 locus of Saccharomyces cerevisiae is important for wild-type levels of chitin synthase III activity. chs5 cells have reduced levels of this activity. To further understand the role of CHS5 in yeast, the CHS5 gene was cloned by complementation of the Calcofluor resistance phenotype of a chs5 mutant. Transformation of the mutant with a plasmid carrying CHS5 restored Calcofluor sensitivity, wild-type cell wall chitin levels, and chitin synthase III activity levels. DNA sequence analysis reveals that CHS5 encodes a unique polypeptide of 671 amino acids with a molecular mass of 73,642 Da. The predicted sequence shows a heptapeptide repeated 10 times, a carboxy-terminal lysine-rich tail, and some similarity to neurofilament proteins. The effects of deletion of CHS5 indicate that it is not essential for yeast cell growth; however, it is important for mating. Deletion of CHS3, the presumptive structural gene for chitin synthase III activity, results in a modest decrease in mating efficiency, whereas chs5delta cells exhibit a much stronger mating defect. However, chs5 cells produce more chitin than chs3 mutants, indicating that CHS5 plays a role in other processes besides chitin synthesis. Analysis of mating mixtures of chs5 cells reveals that cells agglutinate and make contact but fail to undergo cell fusion. The chs5 mating defect can be partially rescued by FUS1 and/or FUS2, two genes which have been implicated previously in cell fusion, but not by FUS3. In addition, mating efficiency is much lower in fus1 fus2 x chs5 than in fus1 fus2 x wild type crosses. Our results indicate that Chs5p plays an important role in the cell fusion step of mating.

FAR1 is required for posttranscriptional regulation of CLN2 gene expression in response to mating pheromone.

Yeast cells arrest during the G1 interval of the cell cycle in response to peptide mating pheromones. The FAR1 gene is required for cell cycle arrest but not for a number of other aspects of the pheromone response. Genetic evidence suggests that FAR1 is required specifically for inactivation of the G1 cyclin CLN2. From these observations, the FAR1 gene has been proposed to encode an element of the interface between the mating pheromone signal transduction pathway and the cell cycle regulatory apparatus. We show here that FAR1 is necessary for the decrease in CLN1 and CLN2 transcript accumulation observed in response to mating pheromone but is unnecessary for regulation of the same transcripts during vegetative growth. However, the defect in regulation of CLN1 expression is dependent upon CLN2. We show that pheromone regulates the abundance of Cln2 at a posttranscriptional level and that FAR1 is required for that regulation. From these observations, we suggest that FAR1 function is limited to posttranscriptional regulation of CLN2 expression by mating pheromone. The failure of mating pheromone to repress CLN2 transcript levels in far1 mutants can be explained by the stimulatory effect of the persistent Cln2 protein on CLN2 transcription via the CLN/CDC28-dependent feedback pathway.

[Sample collection methods for urine culture and analysis]. / Métodos para la recogida de muestras de orina para urocultivo y perfil urinario.

A review of the scientific evidence available on the validity of existing sample collection methods for urine culture and analysis in childhood is presented. Few studies evaluating diagnostic tests have analyzed the various available techniques with respect to valid patterns of reference. Except for clean catch midstream urine samples, there are no estimators of validity (sensitivity, specificity, probability quotients) that can be generalized to most of the techniques and that could guide decision making. Consequently, data from descriptive studies on the risk of contamination, feasibility, safety and acceptability of each technique will have to be considered in decision making. Urine collection by means of adhesive perineal bag is the most widely used method in Spain in children who do not control urine emission. Nevertheless, this technique has a high risk of contamination and a very low positive predictive value, limiting its diagnostic utility. Urethral catheterization and suprapubic bladder aspiration are considered the tests of choice; however, because these tests are invasive, their use is restricted. Therefore, when choosing the technique to be used, the patient's circumstances and our working environment will have to be considered.