Campylobacter jejuni and other emerging Campylobacteraceae in retail beef liver - an underestimated potential source?

Bovine by-products, such as liver, could be an underestimated source of Campylobacter jejuni. Therefore, our aims were to evaluate the occurrence of C. jejuni and other Campylobacteraceae in retail beef liver and characterize their antibiotic resistance (ciprofloxacin, tetracycline, erythromycin and gentamicin) and potential genetic relationship by flagellin gene restriction fragment length polymorphism (flaA-RFLP) and multilocus sequence typing with clinical strains. Seventy-six out of 206 samples (36·9%) were positive for Campylobacter and related organisms. Arcobacter butzleri was the most frequently isolated species (21·8%), followed by C. jejuni (9·7%), C. fetus (7·8%) and C. coli (1%). The C. jejuni strains showed resistance to tetracycline (17·2%) or ciprofloxacin (6·9%), with only one strain resistant to both antibiotics. Meanwhile, 8·3% of ciprofloxacin resistance was observed in C. fetus. The other species showed no resistance. Most of the clonal complexes (CC) in which the C. jejuni genotypes were grouped (CC-21, 42, 48 and 52), coincided with genotypes of clinical strains previously reported in Chile. As such, this study provides evidence that beef liver could be an underestimated route for resistant C. jejuni to humans. Further studies should assess whether this food could play a role in the transmission of other emerging Campylobacteraceae such as those reported here.

Hypervirulent and hypermucoviscous extended-spectrum ß-lactamase-producing Klebsiella pneumoniae and Klebsiella variicola in Chile.

Convergence of virulence and antibiotic-resistance has been reported in Klebsiella pneumoniae, but not in Klebsiella variicola. We, hereby, report the detection and genomic characterization of hypervirulent and hypermucoviscous K. pneumoniae and K.variicola recovered in Chile from health-care associated infections, which displayed resistance to broad-spectrum cephalosporins. One hundred forty-six K. pneumoniae complex isolates were screened by hypermucoviscosity by the "string test." Two hypermucoid isolates, one hypermucoviscous K. pneumoniae (hmKp) and one K. variicola (hmKv), were further investigated by whole-genome sequencing. In vivo virulence was analyzed by the Galleria mellonella killing assay. In silico analysis of hmKp UCO-494 and hmKv UCO-495 revealed the presence of multiple antibiotic-resistance genes, such as blaCTX-M-1, blaDHA-1 and blaLEN-25 among others clinically relevant resistance determinants, including mutations in a two-component regulatory system related to colistin resistance. These genetic features confer a multidrug-resistant (MDR) phenotype in both strains. Moreover, virulome in silico analysis confirmed the presence of the aerobactin gene iutA, in addition to yersiniabactin and/or colicin V encoding genes, which are normally associated to high virulence in humans. Furthermore, both isolates were able to kill G. mellonella and displayed higher virulence in comparison with the control strain. In summary, the convergence of virulence and the MDR-phenotype in K. pneumoniae complex members is reported for the first time in Chile, denoting a clinical problem that deserves special attention and continuous surveillance in South America.

Sífilis maligna, una presentación de sífilis a tener en cuenta / Syphilis Maligna: A Presentation to Bear in Mind

La sífilis maligna es una forma infrecuente de sífilis secundaria asociada a la infección por el VIH, caracterizada clínicamente por nódulos necróticos y lesiones ulceradas generalizadas. Presentamos 4 pacientes diagnosticados de sífilis maligna tras revisar los casos de sífilis diagnosticados en nuestro centro entre 2012 y 2016. Describimos los aspectos epidemiológicos, clínicos, histopatológicos y serológicos, así como su relación con el VIH y la respuesta al tratamiento. Aunque se trate de una forma de sífilis poco frecuente, en los últimos años ha aumentado el número de casos publicados, principalmente pacientes jóvenes infectados por el VIH. Es necesario incluir la sífilis maligna en el diagnóstico diferencial de pacientes infectados por el VIH con lesiones ulceradas y necróticas

Malignant syphilis is an uncommon form of secondary syphilis associated with HIV infection. Clinically, it is characterized by necrotic nodules and generalized ulcerated lesions. We present 4 cases of malignant syphilis diagnosed after evaluating syphilis cases diagnosed at our hospital between 2012 and 2016. We describe the epidemiologic, clinical, histiopathologic, and serologic characteristics of malignant syphilis and explore its response to treatment and association with HIV infection. Although malignant syphilis is uncommon, there has been an increase in the number of cases published in recent years, particularly in young HIV-positive patients. Malignant syphilis must be contemplated in the differential diagnosis of HIV patients with ulcerated, necrotic lesions

Syphilis Maligna: A Presentation to Bear in Mind. / Sífilis maligna, una presentación de sífilis a tener en cuenta.

Malignant syphilis is an uncommon form of secondary syphilis associated with HIV infection. Clinically, it is characterized by necrotic nodules and generalized ulcerated lesions. We present 4 cases of malignant syphilis diagnosed after evaluating syphilis cases diagnosed at our hospital between 2012 and 2016. We describe the epidemiologic, clinical, histiopathologic, and serologic characteristics of malignant syphilis and explore its response to treatment and association with HIV infection. Although malignant syphilis is uncommon, there has been an increase in the number of cases published in recent years, particularly in young HIV-positive patients. Malignant syphilis must be contemplated in the differential diagnosis of HIV patients with ulcerated, necrotic lesions.

Tumoración mal delimitada de larga evolución en el pie de un inmigrante / Poorly Circumscribed, Long-Standing Tumor on the Foot of an Immigrant

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Estudio retrospectivo de las características clínicas, histológicas e inmunológicas en una serie de 9 pacientes con epidermólisis ampollosa adquirida / Retrospective Study of the Clinical, Histologic, and Immunologic Features of Epidermolysis Bullosa Acquisita in 9 Patients

Introducción: La epidermólisis ampollosa adquirida es una enfermedad ampollosa subepidérmica autoinmune causada por autoanticuerpos contra el colágeno VII. Su clínica es heterogénea con afectación de la piel y las mucosas, pudiendo generar secuelas invalidantes. Existen diversas opciones terapéuticas frecuentemente insatisfactorias. Objetivo: Revisar los casos de epidermólisis ampollosa adquirida diagnosticados durante un periodo de 26 años. Material y métodos: Estudio retrospectivo de las características clínicas e inmunopatológicas de 9 pacientes con dicho diagnóstico. Resultados: La mediana de edad de presentación fue de 37 años, el 66,67% de pacientes fueron mujeres. Asociaciones: neoplasias malignas, enfermedad inflamatoria intestinal y procesos autoinmunes. La variante inflamatoria fue la más frecuente (6/9). La histología mostró constantemente una ampolla subepidérmica y la inmunofluorescencia directa la presencia de depósitos lineales de IgG y C3 en la membrana basal. La inmunofluorescencia indirecta fue positiva en 6 pacientes, mostrando en todos ellos un patrón dérmico en piel separada. En 5 pacientes se determinaron los anticuerpos contra el colágeno vii por Enzyme-Linked Immuno Sorbent Assay, de los cuales 2 fueron positivos, e Inmunoblot con NC1 recombinante en 6 casos, positivo en todos ellos. La respuesta terapéutica fue variable. Conclusiones: Se trata de una enfermedad rara, de clínica heterogénea, que puede inducir a confusión con otras enfermedades ampollosas subepidérmicas. Se requiere un alto índice de sospecha y el empleo de todos los métodos disponibles para establecer su diagnóstico. La correcta evaluación de la afectación cutáneo-mucosa y la instauración precoz de la terapéutica adecuada permitirá la detección de sus secuelas y de las complicaciones del tratamiento (AU)

Background: Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease caused by autoantibodies to type VII collagen. The clinical presentation is variable, with skin and mucosal lesions that can cause significant dysfunction. Different treatment options exist, but the results are often unsatisfactory. Objective: To review all the cases of epidermolysis bullosa acquisita (EBA) diagnosed at our hospital over a 26-year period. Materials and methods: We performed a retrospective review of the clinical, histologic, and immunologic features of EBA in 9 patients. Results: Mean age at presentation was 37 years and 66.67% of the patients were women. EBA occurred in association with malignant tumors, inflammatory bowel disease, and autoimmune disorders. The most common variant was inflammatory EBA (6 of the 9 cases). In all 9 patients, histology revealed a subepidermal blister and direct immunofluorescence showed linear deposits of immunoglobulin G and C3 in the basement membrane zone. Indirect immunofluorescence performed on salt-split skin substrate was positive in 6 patients and showed a dermal pattern in all cases. Five patients were tested for autoantibodies to type VII collagen using enzyme-linked immunosorbent assay, with positive results in 2 cases. Immunoblotting using recombinant noncollagenous domains (NC1) of type VII collagen was positive in all 6 cases in which it was performed. Response to treatment was variable. Conclusions: EBA is a rare disease with a variable clinical presentation that can be confused with that of other subepidermal blistering diseases. Correct diagnosis requires a high level of clinical suspicion and the use of all available diagnostic tests. Thorough evaluation of cutaneous and mucosal involvement and prompt initiation of appropriate treatment will ensure the detection and prevention of dysfunction and treatment-related complications (AU)

Retrospective study of the clinical, histologic, and immunologic features of epidermolysis bullosa acquisita in 9 patients.

INTRODUCTION: Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease caused by autoantibodies to type VII collagen. The clinical presentation is variable, with skin and mucosal lesions that can cause significant dysfunction. Different treatment options exist, but the results are often unsatisfactory. OBJECTIVE: To review all the cases of epidermolysis bullosa acquisita (EBA) diagnosed at our hospital over a 26-year period. MATERIALS AND METHODS: We performed a retrospective review of the clinical, histologic, and immunologic features of EBA in 9 patients. RESULTS: Mean age at presentation was 37 years and 66.67% of the patients were women. EBA occurred in association with malignant tumors, inflammatory bowel disease, and autoimmune disorders. The most common variant was inflammatory EBA (6 of the 9 cases). In all 9 patients, histology revealed a subepidermal blister and direct immunofluorescence showed linear deposits of immunoglobulin G and C3 in the basement membrane zone. Indirect immunofluorescence performed on salt-split skin substrate was positive in 6 patients and showed a dermal pattern in all cases. Five patients were tested for autoantibodies to type VII collagen using enzyme-linked immunosorbent assay, with positive results in 2 cases. Immunoblotting using recombinant noncollagenous domains (NC1) of type VII collagen was positive in all 6 cases in which it was performed. Response to treatment was variable. CONCLUSIONS: EBA is a rare disease with a variable clinical presentation that can be confused with that of other subepidermal blistering diseases. Correct diagnosis requires a high level of clinical suspicion and the use of all available diagnostic tests. Thorough evaluation of cutaneous and mucosal involvement and prompt initiation of appropriate treatment will ensure the detection and prevention of dysfunction and treatment-related complications.

DNA sperm damage correlates with nuclear ultrastructural sperm defects in teratozoospermic men.

Sperm morphology has consistently been the best indicator of male fertility. Transmission electron microscopy currently provides the most information on the subcellular details of sperm structure. Recently, assessment of sperm DNA damage has been employed to assess fertility potential. The purpose of this work was to link sperm DNA damage, evaluated by an intercalated fluorescent dye, with the structural characteristics of sperm. Conventional semen analysis was performed on samples from men undergoing fertility evaluation. Thirty men were evaluated and assigned to three subgroups based on strict criteria for sperm morphology: normal morphology (>14% normal forms), intermediate morphology (5-14% normal forms), and poor morphology (<5% normal forms). By quantifying acridine orange-positive cells and ultrastructural sperm defects, we found that the poor morphology pattern group showed a positive association between sperm carrying damaged DNA and the percentage of sperm nucleus with vacuoles (P = 0.01). No statistically significant correlations were established in other ultrastructural characteristics of sperm, including immature chromatin, lytic changes, or abnormal sperm tails. These results suggest that zones without chromatin in the sperm nucleus reflect underlying chromosomal or DNA defects in severe teratozoospermic men. This association should be considered in the evaluation of male fertility.

Identification of potential sources of Staphylococcus aureus in herds with mastitis problems.

Staphylococcus aureus is a common udder pathogen of dairy cows that often causes herd problems. Various mastitis control programs have been used to combat the problem but have not always been efficient in preventing new Staph. aureus infections, indicating the presence of possible sources of infection other than those traditionally considered. Therefore, the aim of the study was to identify potential sources of infection relevant for Staph. aureus mastitis within 5 dairy herds with udder health problems caused by Staph. aureus. Samples were collected from milk of lactating cows, from body sites, and from the environment of lactating cows, dry cows, late pregnant heifers, young heifers 4 to 12 mo old, and heifer calves 0 to 3 mo old. Isolates of Staph. aureus were identified and compared using pulsed-field gel electrophoresis. Four to 7 unique Staph. aureus pulsotypes were found within each herd, with one strain predominating in milk in each herd. The milk pulsotypes were also frequently isolated in body samples, especially on hock skin, and in the immediate environment of lactating cows, and were sometimes found in other animal groups, especially in dry cows and heifer calves 0 to 3 mo old. The prevalence of Staph. aureus in milk and other types of samples varied markedly between herds. Staphylococcus aureus isolates with genotypes indistinguishable from those found in milk also dominated in extra-mammary sites within the dairy herds studied, and hock skin was identified as an important reservoir of Staph. aureus. The results contribute new knowledge necessary to improve strategies for udder health control in herds.

Comparison of a commercialized phenotyping system, antimicrobial susceptibility testing, and tuf gene sequence-based genotyping for species-level identification of coagulase-negative staphylococci isolated from cases of bovine mastitis.

In order to evaluate the usefulness of some phenotypic and genotypic methods for species identification of coagulase-negative staphylococci (CNS), isolates were obtained from bovine cases of clinical and sub-clinical mastitis from different geographical areas in Sweden. By using the Staph-Zym test, antimicrobial susceptibility testing, and sequencing of part of the CNS tuf gene and, when needed, part of the 16S rRNA gene we characterized 82 clinical isolates and 24 reference strains of 18 different species of staphylococci. The genotypic methods identified nine different species of CNS among the 82 milk isolates. A comparison with results obtained by tuf gene sequencing showed that Staph-Zym correctly identified CNS reference strains to species level more often than bovine milk CNS isolates (83% and 61%, respectively). In addition, tests supplementary to the Staph-Zym were frequently needed in both groups of isolates (50% of reference strains and 33% of milk isolates) to obtain an identification of the strain. It is notable that Staph-Zym judged two isolates as CNS, although they belonged to other species, could not give a species name in 11% of the bovine CNS isolates, and gave 28% of the isolates an incorrect species name. The present study indicates that the studied phenotypic methods are unreliable for identification of CNS from bovine intra-mammary infections.

Prolonged diapause and the stability of host-parasitoid interactions.

We investigated the effect on host-parasitoid dynamics of prolonged diapause, a feature of the life history of many animals living in unpredictable environments, by modifying the classical May (J. Anim. Ecol. 47 (1978) 833) host-parasitoid model. We considered three patterns of development of host and parasitoid: (a) prolonged parasitoid diapause controlled by host physiology, (b) parasitoid interference in host development, preventing parasitized hosts from prolonging diapause, and (c) host diapause independent of parasitoid attack. We found that single-year prolonged diapause shifted the boundaries of the May model towards a slight increase in stability. Longer periods of diapause prolongation had a stronger influence, but this influence remained modest if we considered realistic parameter values. In contrast to other recent studies, our results suggest that prolonged diapause does not necessarily compensate for the destabilizing effects of time lags on the influence of parasitoids on population dynamics.

Necesidad de tratamiento y costos en preescolares / Treatment needs and costs in preschool children

El objetivo de este trabajo fue comparar el estdo dentario, la necesidad de tratamiento, el tiempo necesario y la evaluación económica para logar salud bucal en dos grupos de preescolares de diferente riesgo social. Sobre 132 niños pertenecientes a una escuela privada de alto nivel socio-económico (Grupo 1) y 115 niños de un barrio urbano marginal con riesgo social (Grupo II) entre 3 y 5 años de edad, examinadores calibrados realizaron el examen dentario con adecuada fuente de luz, espejo bucal y explorador. Se determinaron los índices ceod, ceos, estado dentario y necesidad de tratamiento de acuerdo a la Encuesta Básica de Salud Buco Dental, OMS 1997. Se estableció la media, el error estándar, la significación de las diferencias y los porcentajes según criterios de la OMS. Los valores obtenidos para el ceod fueron para el Grupo I: 0,43+-0,25 a los 3 años, en el grupo II: 3,56+-0,49. A los 4 años 0,55+-0,18 y 5,8+-0,7 respectivamente. A los 5 años el grupo I: 0,84+-0,22 y el Grupo II: 5,33+-0,46. Al comparar las medias los valores de t resultaron: 3 años: 5,59; 4 años: 7,29; 5 años: 8,98. El 69,58 por ciento de los niños del grupo I estaban libres de caries. En el grupo II 7,14 por ciento. En el Grupo I la presencia de caries alcanzó el 26,31 por ciento y en el Grupo II el 84,84 por ciento. Los costos del programa del grupo I resultó de $1573,19 con un tiempo necesario de 177hs. 10 minutos. Los costos del programa del grupo II resultaron de $6117,44 con un tiempo necesario de tratamiento de 309hs 10 minutos. La necesidad de tratamiento según la OMS fue útil para planificar programas de salud en estos grupos de niños. La inclusión de la evaluación económica posibilitó establecer que a medida que aumenta el riesgo social, mayores son los costos para lograr salud en ese grupo de niños

Necesidad de tratamiento y costos en preescolares / Treatment needs and costs in preschool children

El objetivo de este trabajo fue comparar el estdo dentario, la necesidad de tratamiento, el tiempo necesario y la evaluación económica para logar salud bucal en dos grupos de preescolares de diferente riesgo social. Sobre 132 niños pertenecientes a una escuela privada de alto nivel socio-económico (Grupo 1) y 115 niños de un barrio urbano marginal con riesgo social (Grupo II) entre 3 y 5 años de edad, examinadores calibrados realizaron el examen dentario con adecuada fuente de luz, espejo bucal y explorador. Se determinaron los índices ceod, ceos, estado dentario y necesidad de tratamiento de acuerdo a la Encuesta Básica de Salud Buco Dental, OMS 1997. Se estableció la media, el error estándar, la significación de las diferencias y los porcentajes según criterios de la OMS. Los valores obtenidos para el ceod fueron para el Grupo I: 0,43+-0,25 a los 3 años, en el grupo II: 3,56+-0,49. A los 4 años 0,55+-0,18 y 5,8+-0,7 respectivamente. A los 5 años el grupo I: 0,84+-0,22 y el Grupo II: 5,33+-0,46. Al comparar las medias los valores de t resultaron: 3 años: 5,59; 4 años: 7,29; 5 años: 8,98. El 69,58 por ciento de los niños del grupo I estaban libres de caries. En el grupo II 7,14 por ciento. En el Grupo I la presencia de caries alcanzó el 26,31 por ciento y en el Grupo II el 84,84 por ciento. Los costos del programa del grupo I resultó de $1573,19 con un tiempo necesario de 177hs. 10 minutos. Los costos del programa del grupo II resultaron de $6117,44 con un tiempo necesario de tratamiento de 309hs 10 minutos. La necesidad de tratamiento según la OMS fue útil para planificar programas de salud en estos grupos de niños. La inclusión de la evaluación económica posibilitó establecer que a medida que aumenta el riesgo social, mayores son los costos para lograr salud en ese grupo de niños (AU)

Variability of the electric organ discharge interval duration in resting Gymnotus carapo.

We recorded the electric organ discharges of resting Gymnotus carapo specimens. We analyzed the time series formed by the sequence of interdischarge intervals. Nonlinear prediction, false nearest neighbor analyses, and comparison between the performance of nonlinear and linear autoregressive models fitted to the data indicated that nonlinear correlations between intervals were absent, or were present to a minor extent only. Following these analyses, we showed that linear autoregressive models with combined Gaussian and shot noise reproduced the variability and correlations of the resting discharge pattern. We discuss the implications of our findings for the mechanisms underlying the timing of electric organ discharge generation. We also argue that autoregressive models can be used to evaluate the changes arising during a wide variety of behaviors, such as the modification in the discharge intervals during interaction between fish pairs.

El transporte público y la dinámica de la tuberculosis a nivel poblacional / The public transporte and the dinamic of the tuberculosis in population level

En este artículo hemos introducido, por primera vez, un modelo matemático para el estudio de la dinámica de enfermedades transmisibles, que toma en consideración el impacto de transmisión en dos ambientes diferentes para una población heterogénea. Calculamos el número reproductivo básico y determinamos el impacto de homotransmisiones y heterotransmisiones en el número de infecciones secundarias

El transporte público y la dinámica de la tuberculosis a nivel poblacional / The public transporte and the dinamic of the tuberculosis in population level

En este artículo hemos introducido, por primera vez, un modelo matemático para el estudio de la dinámica de enfermedades transmisibles, que toma en consideración el impacto de transmisión en dos ambientes diferentes para una población heterogénea. Calculamos el número reproductivo básico y determinamos el impacto de homotransmisiones y heterotransmisiones en el número de infecciones secundarias

Transmission and dynamics of tuberculosis on generalized households.

Tuberculosis (TB) transmission is enhanced by systematic exposure to an infectious individual. This enhancement usually takes place at either the home, workplace, and/or school (generalized household). Typical epidemiological models do not incorporate the impact of generalized households on the study of disease dynamics. Models that incorporate cluster (generalized household) effects and focus on their impact on TB's transmission dynamics are developed. Detailed models that consider the effect of casual infections, that is, those generated outside a cluster, are also presented. We find expressions for the Basic Reproductive Number as a function of cluster size. The formula for R0 separates the contributions of cluster and casual infections in the generation of secondary TB infections. Relationships between cluster and classical epidemic models are discussed as well as the concept of critical cluster size.

A model for tuberculosis with exogenous reinfection.

Following primary tuberculosis (TB) infection, only approximately 10% of individuals develop active T.B. Most people are assumed to mount an effective immune response to the initial infection that limits proliferation of the bacilli and leads to long-lasting partial immunity both to further infection and to reactivation of latent bacilli remaining from the original infection. Infected individuals may develop active TB as a consequence of exogenous reinfection, i.e., acquiring a new infection from another infectious individual. Our results in this paper suggest that exogenous reinfection has a drastic effect on the qualitative dynamics of TB. The incorporation of exogenous reinfection into our TB model allows the possibility of a subcritical bifurcation at the critical value of the basic reproductive number R(0)=1, and hence the existence of multiple endemic equilibria for R(0)<1 and the exogenous reinfection rate larger than a threshold. Our results suggest that reducing R(0) to be smaller than one may not be sufficient to eradicate the disease. An additional reduction in reinfection rate may be required. These results may also partially explain the recently observed resurgence of TB.

Combination therapy with hydroxyurea versus without hydroxyurea as first line treatment options for antiretroviral-naive patients.

PURPOSE: This study analyzed whether combination therapy with hydroxyurea (HU) could be considered as first line treatment for antiretroviral-naive patients. METHOD: The prospective open-label study was carried out from March 1996 to May 2000. The antiretroviral treatments were treatment 1-didanosine 400 mg/day, stavudine 60/80 mg/day, and HU 500 mg/day; treatment 2-two nucleosides plus a protease inhibitor; treatment 3-didanosine, indinavir, and HU (500-1,000 mg/day). The viral load (VL) and CD4 determinations were performed at weeks 24, 48, 72, and 96. RESULTS: The sample comprised 284 patients. The distribution of patients by levels of VL and CD4 were similar in the three treatment groups. At week 24, patients receiving T1 and T3 achieved higher percentages of undetectable VL (89% and 81%, respectively) with no significant differences (p =.127) between them. The T2 group showed a lower proportion (58%) of undetectable VL, which was significantly lower than T1 (p <.0001) and T3 (p <.0007). At week 48, the results were similar to week 24. At week 96, nearly all patients had undetectable viral load (UVL). The analysis of adverse effects showed that the T2 group at week 48 had a greater proportion of adverse effects that was significantly different from T1 (p =.0026); T3 had intermediate values with no significant difference from T2 (p =.45) and from T1 (p =.048). At week 48, T1 showed higher adherence level with significant difference from the other two treatments. CONCLUSION: Patients were followed for some 96 weeks and, with an intention-to-treat analysis, were found to do better virologically and Clinically in treatment groups containing HU. The combination of antiretroviral drugs with HU may be an excellent option as initial therapy because of its strong antiretroviral action, its lower rate of adverse effect, and the smaller cost as compared to other regimens.