Crystalglobulinemia manifested as acute renal failure and thrombotic vasculopathy.

Crystalglobulinemia is an extremely rare pathology that is associated in most cases with plasma cell dyscrasia, mainly multiple myeloma. In most cases, it may be the manifestation of incipient gammopathy or it manifests shortly after diagnosis. We report a patient with ischemic lesions of thrombotic origin in lower limbs. Subsequently, renal involvement occurs, in view of this involvement, it is suspected that the patient may have an associated vasculitis. After performing the biopsy and with the subsequent diagnosis of monoclonal gammopathy of uncertain significance, the diagnosis is made. We review the most recent bibliography of patients who have been diagnosed with crystalglobulinemia associated with plasma dyscrasia focusing in those with thrombotic vasculopathy or acute renal failure. In our case, in addition to being associated with monoclonal gammopathy of undetermined significance that is less frequent, the debut of the symptoms is years before the detection of the monoclonal peak. This could speak of patients with a low peak of monoclonal component (not detected by immunoelectrophoresis) who could have kidney and vascular damage.

The role of CDKN2A/B deletions in pediatric acute lymphoblastic leukemia.

The CDKN2A/B genes in the 9p21 chromosomal region are frequently involved in human cancer, including pediatric acute lymphoblastic leukemia (ALL). These genes encode 3 proteins that belong to the RB1 and TP53 pathways and act as tumor suppressors by regulating the G1/S checkpoint of the cell cycle. The prognostic value of deletions in the CDKN2A/B locus in ALL is controversial in part due to the limitations of the methodologies used. Further studies with advanced technologies are needed for elucidation. Future studies would also highlight whether CDK4/CDK6 selective inhibitors might be useful therapies for children with these genetic aberrations.

A comparative study of culture methods and PCR assay for Salmonella detection in poultry drinking water.

The present work compared 2 culture methods and PCR assays for motile and nonmotile Salmonella detection using artificially contaminated poultry drinking water. The specificity was 1 for all methods studied. The accuracy and sensitivity were 1 for all motile strains, whereas these parameters were between 0 and 0.7 for nonmotile Salmonella strains. The positive predictive value and negative predictive value were 1 for all motile Salmonella strains in the 3 methods used. Nonmotile Salmonella strains showed a positive predictive value of 1 in the PCR method. However, the positive predictive value was indeterminate in the tetrathionate (TT) methods for both strains tested and in the modified semisolid Rappaport-Vassiliadis (MSRV) method for Salmonella Pullorum. On the other hand, the negative predictive value was between 0.20 and 0.43 for the 3 methods. The detection level of motile strains was 4 to 7 cfu/25 mL for all methods. Nonmotile Salmonella strains could not be detected in the TT method, whereas only Salmonella Gallinarum could be recovered from 1.1 × 10(1) cfu/25 mL in the MSRV method. In relation to the molecular methods, PCR could detect these strains from 1.1 × 10(4) cfu/25 mL. Extending incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. The kappa coefficient showed that there was an excellent agreement between the 3 methods for motile strains. For nonmotile strains, the agreement was poor between the MSRV and the PCR; there was no agreement when the TT method was compared with the MSRV and the PCR methods. The difference in detection levels obtained with the methods used for motile and nonmotile Salmonella strains and the difficulty in detecting these last strains represents a potential problem when a poultry water sample is considered negative for the presence of Salmonella.

Systematic Review of Psychometric Instruments Used in Research with Psychedelics.

There has been a revival of research that studies the subjective effects of psychedelic drugs on humans. Areas of health science have been studying their possible therapeutic benefits, and psychological measurement instruments are being developed as the studies progress. However, these instruments currently suffer criticism regarding their number and evidence of psychometric quality. This study aims to review which psychometric instruments are available to assess subjective states induced by psychedelics. We systematically searched five databases (Web of Science, Academic Search Premier, EMBASE, CINAHL and PubMed) using psychometrics and psychedelics related terms identifying studies published from 1990 to 2021. Of 857 articles generated from the systematic-search, fifteen met our criteria and were included in the review, evaluating nine instruments: MEQ, 5D-ASC, HRS, PSI, EDI, CEQ, EBI, EDI and PIQ. Eight dealing with phenomenological aspects of the psychedelic experience and one as a screening tool for psychotic or manic episode. The purpose of each instrument, the number of items in each version, the type of scale and their elaboration process were described. The number of instruments used in psychedelic research is growing steadily, but there are still many other parts of the psychedelic experience that lack measurement.

Attitudes scale toward cancer-related cognitive changes - an initial Colombian validation.

OBJECTIVE: The aim of this study was to develop an initial valid tool to measure attitudes toward cancer-related cognitive changes. SUBJECTS AND METHODS: After revising the literature, three main dimensions were hypothesized. Eight judges were contacted to obtain content validity evidence. A robust Exploratory Factor Analysis (EFA) was performed via a parallel analysis with an Unweighted Least Squares (ULS) estimator and polychoric correlations. The results were crossed with sociodemographic variables to find possible statistical differences and estimate the size effect. Analysis was performed in the software Factor and the statistical package R. RESULTS: A sample of 374 participants was obtained, involving oncology patients, their caregivers, and people from the general community. A statistical fit was found in two dimensions: Awareness and Judgments [root mean squared error of approximation (RMSEA) = 0.042, standardized root mean square residual (SRMR) = 0.02, comparative fit index (CFI) = 0.99, Tucker-Lewis index (TLI) = 0.98] with a moderate correlation between them (r = 0.612). Optimal reliability indices were obtained for the total scale and its dimensions. No real statistical difference was found between sociodemographic variables; the interpretation norms were established via the quartiles. CONCLUSIONS: The first attempt to measure the construct of interest was developed with two primary validity evidence based on the content and its internal structure. This instrument could help strengthen the prevention of cancer-related cognitive changes. More research is needed to adhere more valid evidence to the scale.

Molecular docking studies of disubstituted diaryl diselenides as mammalian δ-aminolevulinic acid dehydratase enzyme inhibitors.

δ-Aminolevulinic acid dehydratase (δ-ALAD) is a metalloprotein that catalyzes porphobilinogen formation. This enzyme is sensitive to pro-oxidants and classically used as a biomarker of lead (Pb) intoxication. Diphenyl diselenide [(PhSe)2] and analogs bis(4-chlorophenyl) diselenide [(pCl3PhSe)2], bis(4-methoxyphenyl)diselenide [(pCH3OPhSe)2], and bis[3-(trifluoromethy)phenyl] diselenide [(mCF3PhSe)2] inhibit mammalian δ-ALAD by oxidizing enzyme cysteinyl residues, which are involved in diselenide-induced toxicity. 2-Cysteinyl residues from δ-ALAD are believed to sequentially interact with (PhSe)2. Thus this study utilized protein-ligand docking analyses to determine which cysteinyl residues might be involved in the inhibitory effect of (PhSe)2 and analogs toward δ-ALAD. All diselenides that interact in a similar manner with the active site of δ-ALAD were examined. Docking simulations indicated an important role for π-π interactions involving Phe208 and cation-π interactions involving Lys199 and Arg209 residues with the aromatic ring of (PhSe)2 and analogs. Based upon these interactions an approximation between Se atoms and -SH of Cys124, with distances ranging between 3.3 Å and 3.5 Å, was obtained. These data support our previous postulations regarding the mechanism underlying δ-ALAD oxidation mediated by (PhSe)2 and analogs. Based on protein-ligand docking analyses, data indicated that -SH of Cys124 attacks one of the Se atoms of -SH of (PhSe)2 releasing one PhSeH (selenophenol). Subsequently, the -SH of Cys132 attacks the sulfur atom of Cys124 (from the bond of E-S-Se-Ph indermediate), generating the second PhSe⁻, and the oxidized and inhibited δ-ALAD. In conclusion, AutoDock Vina 1.1.1 was a useful tool to search for diselenides inhibitors of δ-ALAD, and, most importantly, it provided insight into molecular mechanisms involved in enzyme inhibition.

Comparison of 2 culture methods and PCR assays for Salmonella detection in poultry feces.

The present work compared 2 culture methods and the combinations of pre-enrichment and enrichment culture methods with PCR assays [buffered peptone water-PCR and tetrathionate-PCR or modified semisolid Rappaport-Vassiliadis (MSRV)-PCR] for motile and nonmotile Salmonella strain detection using artificially contaminated poultry feces. The specificity and positive predictive values were equal to one in both culture methods. Specificity and positive predictive values, accuracy, sensitivity, and negative predictive values were higher for motile than nonmotile Salmonella strains in culture methods. Only Salmonella enterica serovar Gallinarum was detected by the MSRV method with low accuracy, sensitivity, and negative predictive value. The detection level of motile strains was 2 ×10(0) to 22 × 10(2) cfu per 25 g for these methods, whereas it was 6.9 × 10(2) cfu per 25 g in culture methods for Salmonella Gallinarum. Extending the incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. In general, all selective plating media did not show any statistical differences in the parameters of performance studied. On the other hand, accuracy and sensitivity values were higher in MSRV-PCR and tetrathionate-PCR methods than in the buffered peptone water-PCR method. Specificity and positive predictive values were equal to one in most of the cases. In terms of detection limits, motile Salmonella strains were recovered from 5 × 10(0) cfu per 25 g in MSRV-PCR and tetrathionate-PCR methods, whereas the detection limit was better for nonmotile Salmonella in MSRV-PCR methods than in the tetrathionate-PCR method. Kappa coefficients showed that there was a very good agreement between tetrathionate and MSRV methods for motile Salmonella strains, whereas these methods did not show any concordance for nonmotile Salmonella strains. When buffered peptone water-PCR was compared with both tetrathionate-PCR and MSRV-PCR, agreement was poor for motile Salmonella strains and slight to fair for nonmotile Salmonella strains. The difference in isolation rate obtained with the methods used for motile and nonmotile Salmonella strains must be taken into account when a poultry fecal sample is considered negative for the presence of Salmonella.

A comparative study of culture methods and polymerase chain reaction for Salmonella detection in egg content.

The present work compared 2 culture methods and a PCR assay applied with 2 enrichment methods for the detection of motile and nonmotile Salmonella strains using artificially contaminated egg content. The specificity (Sp) was 1 in all methods. The sensitivity (Se), accuracy (Ac), positive predictive value (PPV), and negative predictive value (NPV) were 1 in both culture methods for motile and nonmotile strains. In reference to the PCR methods, Se and PPV were between 0 and 1, whereas Ac and NPV were between 0.14 and 1. The detection level of motile and nonmotile strains was 5 to 54 cfu per 25 mL for both culture methods, but some strains could not be detected by the PCR methods. Extending incubation time of the enrichment medium to 5 d in the tetrathionate broth (TT), and Muller-Kauffmann tetrathionate-novobiocin broth (MKTTn) methods did not improve the isolation rates. All selective plating media did not show any statistical differences in the parameters of performance studied. Kappa coefficients showed that there was an excellent agreement between the bacteriological methods for all Salmonella strains. The agreement was very good and good between the PCR methods, for motile and nonmotile strains, respectively. However, there was a poor agreement when the PCR and bacteriological methods were compared for motile and nonmotile Salmonella strains. The TT and MKTTn methods are similar in terms of Ac, Se, Sp, PPV, and NPV for different Salmonella strains in egg content. The use of the PCR method cannot improve the same parameters, described before, in this matrix. So, further studies are needed to improve the performance parameters and limit of detection in egg content for the PCR methods, so that test can be used in poultry and food industry.

Cerebrospinal fluid control of neurogenesis induced by retinoic acid during early brain development.

Embryonic-cerebrospinal fluid (E-CSF) plays crucial roles in early brain development including the control of neurogenesis. Although FGF2 and lipoproteins present in the E-CSF have previously been shown to be involved in neurogenesis, the main factor triggering this process remains unknown. E-CSF contains all-trans-retinol and retinol-binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis inducer. In early chick embryo brain, only the mesencephalic-rombencephalic isthmus (IsO) is able to synthesize RA. Here we show that in chick embryo brain development: (1) E-CSF helps to control RA synthesis in the IsO by means of the RBP and all-trans-retinol it contains; (2) E-CSF has retinoic acid activity, which suggests it may act as a diffusion pathway for RA; and (3) the influence of E-CSF on embryonic brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to understand neurogenesis from neural progenitor cells.

Seroprevalence of Salmonella and Mycoplasma infection in backyard chickens in the state of Entre Rios in Argentina.

The present work was conducted to study the seroprevalence of Salmonella, Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS) infection in backyard chickens located in Entre Ríos, Argentina, over 3 periods of time. A total of 2,441 sera samples were collected from backyard chickens belonging to 256 family farms in 16 counties in the state of Entre Ríos from January to May 2003 (first period), December 2004 to April 2005 (second period), and October 2006 to May 2007 (third period). The prevalence of family farms testing seropositive for Salmonella averaged 23.9, 15.9, and 28.6% during the first, second, and third period, respectively. The highest prevalence of Salmonella-seropositive farms recorded (66.7%) was on farms from Concordia county, and the lowest prevalence (0%) was on farms from La Paz county. In contrast, the prevalence of family farms seropositive for MG averaged 32.8, 55.1, and 76.2% during the first, second, and third periods, respectively. The highest prevalence of MG-seropositive farms (100%) was found in the counties of Victoria and Tala, and the lowest prevalence (8.7%) was found on farms on Colón county. The prevalence of family farms seropositive for MS averaged 68.6 and 100% during the first and second periods, respectively. The highest prevalence of MS-seropositive farms (100%) was on farms in 85% of the counties tested, and the lowest prevalence (21.7%) was on farms from Colón county. Salmonella, MG, and MS infection are present at high levels in backyard chicken farms, and this presents a high risk to commercial poultry production in Entre Ríos, the state with the highest chicken population and density in Argentina.

A comparative study of culture methods and polymerase chain reaction assay for Salmonella detection in poultry feed.

The present work compared 2 culture methods and PCR assay for the detection of motile and non-motile Salmonella strains using artificially contaminated poultry feed. The specificity was 1 in all methods. The accuracy and sensitivity were between 0.5 and 1 for motile Salmonella strains, whereas these parameters were between 0 and 0.6 for non-motile Salmonella strains. The positive predictive value was 1 for tetrathionate (TT), PCR, and modified semisolid Rappaport-Vassiliadis (MSRV) methods in most of the strains studied. The negative predictive value of each method was very low for non-motile Salmonella strains. The detection level of motile strains was 8 to 20 cfu/25 g for all methods, whereas it was ≥10(4) cfu/25 g in culture methods for non-motile Salmonella strains. In general, the PCR method detected lower non-motile Salmonella contamination levels in feed than did culture methods. Extending incubation time of the enrichment medium to 6 d in the TT method did not improve the isolation rates. All selective plating media did not show any statistical differences in the parameters of performance studied. Kappa coefficients showed that there was good agreement between TT and MSRV methods, and MSRV and PCR methods for motile Salmonella strains in poultry feed samples. The agreement was fair between TT and PCR methods for these strains. For non-motile Salmonella strains, there was poor (TT and MSRV methods), slight (PCR and TT methods), and fair (MSRV and PCR methods) agreement. The TT, MSRV, and PCR methods are similar in terms of accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for different motile Salmonella strains in poultry feed. For non-motile Salmonella strains, the use of the PCR method improves the same parameters, described before, in this matrix. The difference in detection levels obtained with the methods used for motile and nonmotile Salmonella strains and the difficulty to detect these last strains represent a potential problem, when a poultry feed sample is considered negative for the presence of Salmonella.

Support vector machine for EELS oxidation state determination.

Electron Energy-Loss Spectroscopy (EELS) is a powerful and versatile spectroscopic technique used to study the composition and local optoelectronic properties of nanometric materials. Currently, this technique is generating large amounts of spectra per experiment, producing a huge quantity of data to analyse. Several strategies can be applied in order to classify these data to map physical properties at the nanoscale. In the present study, the Support Vector Machine (SVM) algorithm is applied to EELS, and its effectiveness identifying EEL spectra is assessed. Our results evidence the capacity of SVM to determine the oxidation state of iron and manganese in iron and manganese oxides, based on the ELNES of the white lines of the transition metal. The SVM algorithm is first trained with given datasets and then the resulting models are tested through noisy test data sets. We demonstrate that SVM exhibits a very good performance classifying these EEL spectra, despite the usual level of noise and instrumental energy shifts.

Genetic predisposition to fetal and neonatal cancer.

BACKGROUND: Neonatal tumors represent an extremely rare and heterogeneous disease with an unknown etiology. Due to its early onset, it has been proposed that genetic factors could play a critical role; however, germline genetic analysis is not usually performed in neonatal cancer patients PATIENTS AND METHODS: To improve the identification of cancer genetic predisposition syndromes, we retrospectively review clinical characteristics in 45 patients with confirmed tumor diagnosis before 28 days of age, and we carried out germline genetic analysis in 20 patients using next-generation sequencing and directed sequencing. RESULTS: The genetic studies did not find any germline mutation except patients diagnosed with bilateral retinoblastoma who harbored RB1 germline mutations. CONCLUSIONS: Our results suggest that genetic factors have almost no higher impact in most neonatal tumors. However, since the heterogeneity of the tumors and the small sample size analyzed, we recommend complementary and centralized germline studies to discard the early onset as an additional criterion to take into account to improve the identification of cancer genetic predisposition syndromes in neonates.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella in backyard chickens from Entre Rios, Argentina.

This study was conducted to estimate the apparent prevalence of Salmonella spp. in birds kept under backyard system in Entre Ríos, Argentina, and determine the performance of two selective plating media used for Salmonella isolation, and the antimicrobial resistance of the isolated. Also, the association of farms characteristics with Salmonella presence was evaluated. A total of 657 backyard chickens and 15 gooses were sampled one time by cloacal swab, belonging to 51 and one family farms, respectively, and four counties in Entre Rios state from April 2014 to May 2015. Only four samples from backyard chickens belonged to three family farms from Uruguay County were positive to Salmonella spp., so the apparent prevalence was 0.6% for this kind of chicken. Four serovars were isolated (Salmonella ser. Lille, S. ser. Newport, S. ser. Enteritidis and S. ser. Rissen), which were susceptible to all antibiotics tested with the exception of erythromycin. For Hektoen enteric agar and brilliant green agar, relative specificity and positive predictive value were 1, and the relative sensitivity and negative predictive value did not show any difference between them. The agreement was very good between these two plating media. None of the variables studied could be selected to calculate the risk factors associated with Salmonella isolation because p > .15. Although the prevalence of Salmonella spp. is low in backyard birds in Entre Rios, the presence of S. ser. Enteritidis should not be discounted, because it is found in the county that concentrates a large population of intensive poultry production in the state.

Prevalence, antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella spp. in free-ranging waterfowl from Entre Rios, Argentina.

The present study was conducted to estimate the apparent prevalence of Salmonella spp. in free-ranging waterfowl that inhabitant Entre Ríos, Argentina, determine the antimicrobial resistance of the isolated, and compare the performance of two selective plating media used for Salmonella isolation. Five hundred ninety nine free-living waterfowl were sampled one time by cloacal swab from April 2014 to July 2016. Only 6 samples from waterfowl belonged to all counties sampled were positive to Salmonella spp., so the apparent prevalence was 1%. Four serovars were isolated (Salmonella ser. Typhimurium, S. ser. Schwarzengrund, S. enterica subsp. I [4,12: i: -], S. enterica subsp. IIIb [60: r: e, n, x, z15]), which were susceptible to 15 antibiotics tested and resistant to erythromycin. Furthermore, some strains showed an intermediate resistant to neomycin, ciprofloxacin and/or streptomycin. The multiple antibiotic resistances index was 0.05. For Hektoen enteric agar and Salmonella Shigella agar, the relative accuracy, sensitivity, specificity, positive predictive value, and negative predictive value did not show any difference between them. The agreement was good between these two plating-media and the difference between these plating-media was not statistically significant. The low prevalence of Salmonella spp. in waterfowl in Entre Rios should not be discounted, since Salmonella ser. Typhimurium was the most prevalent serovar and some free-ranging waterfowl species studied can migrate from/to different countries, increasing the possibility to cross-contaminated Salmonella to resident or other migrant birds.

MRPL53, a New Candidate Gene for Orofacial Clefting, Identified Using an eQTL Approach.

A valuable approach to understand how individual and population genetic differences can predispose to disease is to assess the impact of genetic variants on cellular functions (e.g., gene expression) of cell and tissue types related to pathological states. To understand the genetic basis of nonsyndromic cleft lip with or without cleft palate (NSCL/P) susceptibility, a complex and highly prevalent congenital malformation, we searched for genetic variants with a regulatory role in a disease-related tissue, the lip muscle (orbicularis oris muscle [OOM]), of affected individuals. From 46 OOM samples, which are frequently discarded during routine corrective surgeries on patients with orofacial clefts, we derived mesenchymal stem cells and correlated the individual genetic variants with gene expression from these cultured cells. Through this strategy, we detected significant cis-eQTLs (i.e., DNA variants affecting gene expression) and selected a few candidates to conduct an association study in a large Brazilian cohort (624 patients and 668 controls). This resulted in the discovery of a novel susceptibility locus for NSCL/P, rs1063588, the best eQTL for the MRPL53 gene, where evidence for association was mostly driven by the Native American ancestry component of our Brazilian sample. MRPL53 (2p13.1) encodes a 39S protein subunit of mitochondrial ribosomes and interacts with MYC, a transcription factor required for normal facial morphogenesis. Our study illustrates not only the importance of sampling admixed populations but also the relevance of measuring the functional effects of genetic variants over gene expression to dissect the complexity of disease phenotypes.

Metas internacionais de segurança do paciente na atenção primária à saúde: uma revisão integrativa / International patient safety goals in the Primary Health Care: an integrative review

A atenção primária em saúde (APS) representa o primeiro contato dos indivíduos com a porta de entrada dos sistemas de saúde. A implementação de estratégias como as Metas Internacionais de Segurança do Paciente (MISP) neste nível de atenção em saúde surge como alternativa para qualificação do cuidado. O presente estudo tem como objetivo investigar na literatura, estudos relacionados às MISP no âmbito da APS. Trata-se de uma revisão de literatura integrativa com busca nas bases de dados Scopus, MEDLINE/Pubmed, LILACS e Scielo, de 2012 a 2019. Dos 43 artigos selecionados, 20,9% apresentaram origem na Espanha, seguidos de Brasil e Reino Unido com sete (16,3%) estudos cada. A MISP 3, sobre o uso seguro de medicamentos, foi a mais prevalente, 65,4% dos estudos, e envolveu estudos com as temáticas de polifarmácia, medicamentos potencialmente inapropriados, revisão de medicamentos e conciliação medicamentosa. A presente revisão integrativa contribuiu para ampliar o conhecimento sobre a segurança do paciente no âmbito da APS e para ressaltar a necessidade da realização de mais estudos referentes às seis MISP, muitas delas, já bem descritas e debatidas no ambiente hospitalar, mas com discreta abordagem mesmo com igual relevância, no âmbito da APS. (AU)

The Primary Health Care (PHC) characterizes the first contact of citizens with the health systems. The implementation of strategies such as the International Patient Safety Goals (IPSG) in this level of healthy attention appears as an alternative to qualify care. The study aims to investigate, thought science literature, studies related to IGPS in the field of PHC. It is an integrative review based on data from Scopus, MEDLINE/Pubmed, LILACS and Scielo, from 2012 to 2019. Out of 43 selected studies, the majority has analyzed data from the Spain (20.9%), followed by Brazil and United Kingdom, seven (16.4%) studies each. The MISP 3, regarding the improve the safety of medications was the most prevalent, 65.4% of the studies, sustaining themes as polypharmacy, potentially inappropriate medication, medication review and medication reconciliation. This integrative review contributes to increase the knowledge about the patient’s safety in the field of PHC and emphasizes the need for further studies related to the six IGPS. Although most of them has already been described and debated in the hospital environment, the PHC remains an overlooked field of study. (AU)

Salmonella spp. contamination in commercial layer hen farms using different types of samples and detection methods.

The performance of detection methods (culture methods and polymerase chain reaction assay) and plating media used in the same type of samples were determined as well as the specificity of PCR primers to detected Salmonella spp. contamination in layer hen farms. Also, the association of farm characteristics with Salmonella presence was evaluated. Environmental samples (feces, feed, drinking water, air, boot-swabs) and eggs were taken from 40 layer hen houses. Salmonella spp. was most detected in boot-swabs taken around the houses (30% and 35% by isolation and PCR, respectively) follow by fecal samples (15.2% and 13.6% by isolation and PCR, respectively). Eggs, drinking water, and air samples were negative for Salmonella detection. Salmonella Schwarzengrund and S. Enteritidis were the most isolated serotypes. For plating media, relative specificity was 1, and the relative sensitivity was greater for EF-18 agar than XLDT agar in feed and fecal samples. However, relative sensitivity was greater in XLDT agar than EF-18 agar for boot-swab samples. Agreement was between fair to good depending on the sample, and it was good between isolation and PCR (feces and boot-swabs), without agreement for feed samples. Salmonella spp. PCR was positive for all strains, while S. Typhimurium PCR was negative. Salmonella Enteritidis PCR used was not specific. Based in the multiple logistic regression analyses, categorization by counties was significant for Salmonella spp. presence (P-value = 0.010). This study shows the importance of considering different types of samples, plating media and detection methods during a Salmonella spp. monitoring study. In addition, it is important to incorporate the sampling of floors around the layer hen houses to learn if biosecurity measures should be strengthened to minimize the entry and spread of Salmonella in the houses. Also, the performance of some PCR methods and S. Enteritidis PCR should be improved, and biosecurity measures in hen farms must be reinforced in the region of more concentrated layer hen houses to reduce the probability of Salmonella spp. presence.