Mortality and sequelae of tuberculous meningitis in a high-resource setting: A cohort study, 1990–2017 / Mortalidad y secuelas de la meningitis tuberculosa en Barcelona (España): Estudio de cohortes, 1990-2017

Introduction: Tuberculous meningitis (TBM), the most serious form of tuberculosis, results in high mortality and long-term disability in low-resource countries. We investigated temporal trends in mortality and sequelae in a high-resource low-incidence country. Methods: We performed a retrospective cohort study of all adult patients with TBM at two third-level teaching hospitals in Barcelona (Spain), between January 1990 and December 2017, assessing temporal trends in mortality and sequelae after 12 months over four consecutive 7-year time windows. Rates observed across the four periods were adjusted for covariates. Results: Of the 135 cases included, all but one started tuberculosis (TB) treatment and 120 (89.6%) received rifampicin, isoniazid, and pyrazinamide, with or without ethambutol. The probability of being alive at month 12 was 81.8%, with no differences among the four periods: in comparison with the 1990–1996 period, the adjusted hazard ratios and 95% confidence intervals (CI) were 2.55 (0.71–9.25), 0.70 (0.13–3.85), and 1.29 (0.28–5.91) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Sequelae were present in 28.3% at month 12, with no differences across the four periods in the adjusted analysis: in comparison with the 1990–1996 period, the odds ratios and 95% CIs were 0.80 (0.09–7.22); 1.94 (0.21–17.96), and 2.42 (0.25–23.07) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Conclusion: This study shows that TBM still causes high mortality and disability even in a high-resource low-incidence TB setting and without improvement over time.(AU)

Introducción: La meningitis tuberculosa (TBM), la forma más grave de tuberculosis, provoca una alta mortalidad y discapacidad a largo plazo en países con bajos recursos. Nuestro objetivo es investigar la tendencia temporal de la mortalidad y las secuelas en un país con recursos elevados y baja incidencia. Métodos: Hemos realizado un estudio de cohortes retrospectivo de los pacientes adultos con TBM en dos hospitales universitarios de tercer nivel en Barcelona (España), entre 1990 y 2017, evaluando las tendencias temporales de mortalidad y secuelas a los 12 meses, comparando cuatro periodos consecutivos de siete años. Las tasas observadas en los cuatro periodos se han ajustado por covariables. Resultados: De los 135 casos incluidos, todos menos uno inició tratamiento antituberculoso y 120 (89,6%) recibieron rifampicina, isoniazida y pirazinamida, con o sin etambutol. La probabilidad de estar vivo a los 12 meses fue de 81,8%, sin diferencias entre los cuatro periodos: en comparación con el periodo 1990-1996, los coeficientes de riesgo ajustados y los intervalos de confianza (IC) del 95% fueron 2,55 (0,71-9,25), 0,70 (0,13-3,85) y 1,29 (0,28-5,91) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Las secuelas estaban presentes en 28,3% en el mes 12, sin diferencias entre los cuatro periodos en el análisis ajustado: en comparación con el periodo 1990-1996, los coeficientes de probabilidad y los IC 95% fueron 0,80 (0,09-7,22); 1,94 (0,21-17,96) y 2,42 (0,25-23,07) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Conclusión: Este estudio muestra que la TBM todavía causa una alta mortalidad y discapacidad sin mejoría con el tiempo, incluso en un entorno con baja incidencia de tuberculosis y con elevados recursos.(AU)

Cambios en las características epidemiológicas y en el pronóstico de la hepatitis crónica B en personas que viven con VIH / Epidemiological characteristic and prognosis changes in chronic hepatitis B in people living with HIV

Introducción: La vacunación, los avances en el tratamiento frente al virus de la hepatitis B (VHB) y los cambios epidemiológicos producidos en España en las últimas décadas han podido modificar las características y el pronóstico de la hepatitis crónica B (HCB) en personas que viven con VIH (PVIH). Métodos: Estudio observacional retrospectivo donde se incluyeron PVIH-HCB en seguimiento en una unidad de referencia madrileña hasta el año 2019. Se comparó la incidencia y las características epidemiológicas y clínicas según el momento del diagnóstico (antes del año 2000 y posteriormente en periodos de cinco años). Además, se realizó un estudio longitudinal retrospectivo evaluando la tasa de mortalidad, descompensación hepática y factores asociados. Resultados: De 5.452 PVIH, 160 presentaban HCB en el momento basal (prevalencia 2,92%, IC 95%: 2,5-3,4), 85,6% hombres, edad mediana al diagnóstico 32,1 (27-37,2) años. La incidencia (2,4/100 pacientes-año) no varió en los diferentes periodos. Los pacientes diagnosticados antes del 2000 (n = 87) comparados con los diagnosticados entre 2015-2019 (n = 11) con mayor frecuencia eran nativos españoles (90,8 vs. 18,2%), habían consumido drogas intravenosas (55,2 vs. 0), tenían antecedentes de hepatitis C (40 vs. 9,1%) y delta (30,4 vs. 0) y mayor afectación hepática (24,1% cirróticos vs. 0). Tras un seguimiento de 20,4 años, 23 pacientes murieron (7,1/1.000 pacientes-año) y 19 presentaron descompensación hepática (4,9/1.000 pacientes-año), todos diagnosticados antes del año 2010. La mortalidad se asoció con mayor fibrosis hepática basal estimada por Fibroscan® (HR 1,06; IC 95%: 1,03-1,09). Conclusión: Las PVIH-HCB con diagnóstico previo al año 2000 son más frecuentemente de nacionalidad española, infectadas por vía parenteral y con mayor prevalencia de otras coinfecciones. Los pacientes diagnosticados antes del 2010 tienen peor pronóstico condicionado por presentar mayor grado de fibrosis hepática.(AU)

Introduction: Due to hepatitis B virus (HBV) treatment and vaccination during the last decades in Spain, epidemiological and prognosis of chronic hepatitis B (CHB) may have changed. Methods: Retrospective review of CHB–HIV coinfected patients in a single reference center in Madrid until year 2019. We compared incidence, epidemiological and clinical characteristics according diagnosis period (before 2000, 2000–2004, 2005–2009, 2010–2014, 2015–2019). A retrospective longitudinal study was done to assess mortality, related risk factors and hepatic decompensation. Results: Out of 5452 PLHIV, 160 had CHB (prevalence 2.92%; 95% CI: 2.5–3.4), 85.6% were men, median age 32.1 (27–37.2). Incidence rate did not change over the years (2.4/100 patients-year). PLHIV with CHB diagnosed before year 2000 (n = 87) compared with those diagnosed between 2015 and 2019 (n = 11) were more often native-Spanish (90.8% vs. 18.2%), had infected using intravenous drugs (55.2% vs. 0), were coinfected with hepatitis C (40% vs. 9.1%) or hepatitis delta virus (30.4% vs. 0) and had more severe liver disease (cirrhosis 24.1% vs. 0). After a median follow-up of 20.4 years, 23 patients died (7.1/1000 patients-year) and 19 had liver decompensation (4.9/1000 patients-year). All deaths and liver decompensation occurred in patients diagnosed before year 2010. Mortality was associated with higher liver fibrosis in Fibroscan® (HR 1.06, 95% CI: 1.03–1.09). Conclusion: The epidemiology of CHB in PLHIV in our cohort is changing with less native Spanish, more sexually transmitted cases and less coinfection with other hepatotropic virus. Patients diagnosed before 2010 have worst prognosis related to higher grades of liver fibrosis.(AU)

Impact on tuberculosis diagnostic during COVID-19 pandemic in a tertiary care hospital / Impacto de la pandemia COVID-19 en el diagnóstico de tuberculosis en un hospital de tercer nivel

Introduction: The aim of this study is to review how did the first three COVID-19 waves affected the diagnostic of tuberculosis and to describe the extra-pulmonary Mycobacterium tuberculosis complex (TB) diagnosis. Materials and methods: A retrospective observational study was done during the first three waves of pandemic to ascertain the impact on TB samples and to recover the extra-pulmonary TB cases we included the first two years of COVID-19. All relevant data was recovered from hospital and Clinical Microbiology records. Results: Prepandemic period showed an average of 44 samples per week for TB study; during the first three waves this number dropped to 23.1 per week. A reduction of 67.7% of pulmonary TB diagnosis was observed and an increase of 33.3% diagnosis of extra-pulmonary TB was noted when comparing pre-pandemic and pandemic period. Discussion: The number of declared cases and samples for TB diagnosis dropped during the first three COVID-19 waves due to the overstretched Public Health System which could lead to a delay in diagnosis, treatment and to the spread of TB disease in the general population. Surveillance programs should be reinforced to avoid this.(AU)

Introducción: El objetivo de este estudio fue revisar cómo afectaron las primeras tres olas de la pandemia COVID-19 al diagnóstico de tuberculosis y describir el diagnóstico de las infecciones extrapulmonares causadas por Mycobacterium tuberculosis complex (TB). Materiales y métodos: Se realizó un estudio observacional y retrospectivo durante el periodo que incluye las tres primeras olas de la pandemia para valorar el impacto en las muestras de TB y para valorar el diagnóstico de las TB extrapulmonares se amplió el periodo de estudio para incluir los 2 primeros años de la COVID-19. Todos los datos relevantes se extrajeron de la base de datos del hospital y del Servicio de Microbiología y Parasitología Clínica. Resultados: En el periodo prepandémico se recibían una media de 44 muestras por semana para el estudio de TB; durante las tres primeras olas ese número cayó a 23,1 por semana. Se observó una reducción del 67,7% en el diagnóstico de la TB pulmonar y un aumento del 33,3% en el diagnóstico de la TB extrapulmonar cuando se comparó con los datos prepandemia. Discusión: El número de casos declarados y el número de muestras para el diagnóstico de TB cayó durante las tres primeras olas del COVID-19 debido a la saturación del Sistema Nacional de Salud, lo que podría llevar a un retraso en el diagnóstico, tratamiento y a un aumento de la transmisión en la población general. Los sistemas de vigilancia deberían reforzarse para evitar esto.(AU)

Efectividad de la vacuna antigripal para prevenir casos graves de gripe. Temporada 2022/2023 / Effectiveness of influenza vaccine in preventing severe cases of influenza: Season 2022/2023

Introducción: La gripe supone una importante carga en términos de morbimortalidad, siendo la vacunación una de las medidas más efectivas para su prevención. Por lo que el objetivo de este estudio es conocer la efectividad de la vacuna antigripal para prevenir casos de gripe grave en los pacientes ingresados en un hospital de tercer nivel durante la temporada 2022/23. Metodología: Estudio de casos y controles. Se incluyeron todos los pacientes hospitalizados con resultado positivo en una RT-PCR de gripe. Se consideró caso a aquellos que cumplieron criterio de caso grave (neumonía, sepsis, fallo multiorgánico, ingreso en la UCI o exitus). Quienes no los cumplían se consideraron controles. Se calculó la efectividad vacunal (EV) para prevenir los casos graves y su intervalo de confianza al 95%. Resultados: Un total de 403 pacientes ingresaron con gripe confirmada. Noventa y ocho (24,3%) de ellos desarrollaron gripe grave. Del total, el 50,6% fueron varones y el 47,1% fueron mayores de 65 años. La EV ajustada por tipo de gripe, edad y ciertas comorbilidades fue del 40,6% (−21,9-71,1). En un análisis segmentado, la vacuna de la gripe resultó efectiva para la prevención de los casos graves en todas las categorías. Resultó especialmente relevante en el grupo de 65 años o más (EVa=60,9%; −2,0-85,0) y en los pacientes con gripe A (EVa=56,7%; 1,5-80,9). Conclusiones: La vacunación antigripal redujo notablemente la aparición de casos graves de gripe en los pacientes hospitalizados, por tanto, sigue siendo la principal estrategia para reducir la morbimortalidad y los costes asociados.(AU)

Introduction: Influenza poses a significant burden in terms of morbidity and mortality, with vaccination being one of the most effective measures for its prevention. Therefore, the aim of this study is to determine the effectiveness of the influenza vaccine in preventing cases of severe influenza in patients admitted to a tertiary hospital during the 2022/23 season. Methods: Case-control study. All hospitalised patients with a positive result in an RT-PCR for influenza were included. Those who met the criteria for a severe case (pneumonia, sepsis, multi-organ failure, admission to ICU or exitus) were considered cases. Those who did not meet these criteria were considered controls. Vaccine effectiveness (VE) to prevent severe cases and its 95% confidence interval were calculated. Results: A total of 403 patients were admitted with confirmed influenza. Of these, 98 (24.3%) developed severe influenza. Of the total, 50.6% were men and 47.1% were over 65 years of age. VE adjusted for influenza type, age and certain comorbidities was 40.6% (−21.9 to 71.1). In a segmented analysis, influenza vaccine was effective in preventing severe cases in all categories. It was particularly relevant in the 65+ age group (VEa=60.9%; −2.0 to 85.0) and in patients with influenza A (VEa=56.7%; 1.580.9). Conclusion: Influenza vaccination markedly reduced the occurrence of severe cases of influenza in hospitalised patients, therefore, it remains the main strategy to reduce morbidity and mortality and associated costs.(AU)

Oportunidades perdidas en la detección temprana de la infección por VIH en pacientes con infecciones de transmisión sexual: un estudio de vida real / Missed opportunities in the early detection of HIV infection in patients with sexually transmitted infections: A real-life study

Introducción: Las enfermedades de transmisión sexual, como la cervicitis, la proctitis y la uretritis, se asocian a altas tasas de infección por VIH. Ante la sospecha de estas patologías, se debería solicitar una serología del VIH. Material y métodos: Estudio retrospectivo realizado durante 2018 en el Hospital Costa del Sol (Marbella, Málaga). Se revisaron las serologías para el VIH solicitadas en pacientes a los que se les pidió una PCR para Chlamydia trachomatis y Neisseria gonorrhoeae. Resultados: Se valoraron 1.818 pacientes, en los que se realizó serología para el VIH al 44,7%, de las cuales 14 (1,7%) resultaron positivas. El 55,3% restante fueron oportunidades perdidas de diagnóstico. Conclusiones: Las infecciones por C.trachomatis y N.gonorrhoeae están asociadas a una elevada tasa de infección oculta por el VIH. El grado de sospecha de VIH en esta población sigue siendo bajo, y resulta esencial que se refuerce ante la posibilidad de infección por estas patologías.(AU)

Introduction: Sexually transmitted diseases such as cervicitis, proctitis and urethritis are associated with high rates of HIV infection. When these pathologies are suspected, HIV serology should be requested. Material and methods: A Retrospective study was performed during 2018 at the Hospital Costa del Sol (Marbella, Málaga, Spain). HIV serologies requested in patients who were asked for PCR for Chlamydia trachomatis and Neisseria gonorrhoeae were reviewed. Results: A total of 1818 patients were evaluated, in which HIV serology was performed in 44.7%, of which 14 (1.7%) were positive. The remaining 55.3% were missed diagnostic opportunities. Conclusions: C.trachomatis and N.gonorrhoeae infections are associated with a high rate of occult HIV infection. The degree of suspicion of HIV in this population remains low and it is essential that it be reinforced in the presence of the possibility of infection by these pathologies.(AU)

BCGitis con afectación de aneurisma aortoilíaco: aportación de dos casos y revisión de la literatura / BCGitis with aortoiliac aneurysm involvement: Report of two cases and review of the literature

La BCGitis es una complicación infrecuente del tratamiento intravesical con Bacillus Calmette-Guérin para el cáncer superficial de vejiga de alto grado y el carcinoma in situ. Puede causar afectación vascular. Presentamos 2 casos y una revisión de la literatura de series de casos publicadas en los 10 años previos a la finalización de este trabajo en abril de 2022, que describiesen un caso de aneurisma micótico aortoilíaco tras recibir este tratamiento. De los 51 casos incluidos (49 revisados y 2 originales), el 100% eran hombres, 82% tenían más de 65 años. La mediana del período de latencia fue de 15 meses (RIQ 18). La localización más frecuente fue la aorta abdominal, documentándose rotura en el 45,1%. El síntoma más frecuente fue dolor abdominal o lumbar (61%), seguido de síndrome general (49%). Asoció absceso retroperitoneal un 39,2%. La mortalidad atribuible fue de 13,6%. La BCGitis debería incluirse como diagnóstico diferencial de pacientes que hayan recibido terapia con BCG y presenten afectación vascular, incluso años tras el tratamiento.(AU)

BCGitis is a rare complication after intravesical administration of Bacillus Calmette-Guérin for high-grade superficial bladder cancer and carcinoma in situ. May cause vascular involvement. We present two cases and a review of the literature of the case reports published on the 10 years prior to April of 2022, when this project was finished, which described a case of aortoiliac mycotic aneurysm after receiving this treatment. Of the 51 cases included (49 revised and 2 original), 100% were men, 82% were older than 65 years. The median latency period was 15 months (IQR 18). The most frequent location was the abdominal aorta, rupture occurred in 45.1% of patients. The most frequent symptom was abdominal or lumbar pain (61%), followed by general syndrome (49%). In 39.2% cases, it was associated with retroperitoneal abscesses. Attributable mortality was 13.6%. BCGitis should be included in the differential diagnosis in patients who have received BCG therapy and present vascular involvement, even years after being treated.(AU)

Antimicrobial use and resistance in food animal production: food safety and associated concerns in Sub-Saharan Africa / Uso de antimicrobianos y resistencia en la producción animal para consumo humano: inocuidad de los alimentos y preocupaciones asociadas en el África subsahariana

The use of antimicrobials in food animal (FA) production is a common practice all over the world, with even greater usage and dependence in the developing world, including Sub-Saharan Africa (SSA). However, this practice which serves obvious economic benefits to producers has raised public health concerns over the last decades, thus driving the selection and dissemination of antimicrobial resistance and adversely impacting food safety and environmental health. This review presents the current and comprehensive antimicrobial usage practices in food animal production across SSA. We further highlighted the overall regional drivers as well as the public health, environmental, and economic impact of antimicrobial use in the production of food animals. Antimicrobial use is likely to increase with even exacerbated outcomes unless cost-effective, safe, and sustainable alternatives to antibiotics, especially probiotics, prebiotics, bacteriocins, antimicrobial peptides, bacteriophages, vaccines, etc. are urgently advocated for and used in food animal production in SSA. These, in addition to the implementation of strong legislation on antimicrobial use, and improved hygiene will help mitigate the public health concerns associated with antimicrobial use in food animals and improve the well-being and safety of food animals and their products.(AU)

Histone acetyltransferases derived RW20 protects and promotes rapid clearance of Pseudomonas aeruginosa in zebrafish larvae / La histona acetiltransferasa derivada RW20 protege y promueve la rápida eliminación de Pseudomonas aeruginosa en larvas de pez cebra

Pseudomonas is a group of bacteria that can cause a wide range of infections, particularly in people with weakened immune systems, such as those with cystic fibrosis or who are hospitalized. It can also cause infections in the skin and soft tissue, including cellulitis, abscesses and wound infections. Antimicrobial peptides (AMPS) are the alternative strategy due to their broad spectrum of activity and act as effective treatment against multi-drug resistance pathogens. In this study, we have used an AMP, RW20 (1RPVKRKKGWPKGVKRGPPKW20). RW20 peptide is derived from the histone acetyltransferases (HATs) of the freshwater teleost, Channa striatus. The antimicrobial prediction tool has been utilized to identify the RW20 sequence from the HATs sequence. We synthesized the peptide to explore its mechanism of action. In an in vitro assay, RW20 was challenged against P. aeruginosa and we showed that RW20 displayed antibacterial properties and damaged the cell membrane. The mechanism of action of RW20 against P. aeruginosa has been established via field emission scanning electron microscopy (FESEM) as well as fluorescence assisted cell sorter (FACS) analysis. Both these experiments established that RW20 caused bacterial membrane disruption and cell death. Moreover, the impact of RW20, in-vivo, was tested against P. aeruginosa-infected zebrafish larvae. In the infected larvae, RW20 showed protective effect against P. aeruginosa by increasing the larval antioxidant enzymes, reducing the excess oxidative stress and apoptosis. Thus, it is possible that HATs-derived RW20 can be an efficient antimicrobial molecule against P. aeruginosa.(AU)

Characterization of a putative metal-dependent PTP-like phosphatase from Lactobacillus helveticus 2126 / Caracterización de una supuesta fosfatasa similar a PTP dependiente de metales de Lactobacillus helveticus 2126

To date, there are very limited reports on sequence analysis and structure-based molecular modeling of phosphatases produced by probiotic bacteria. Therefore, a novel protein tyrosine-like phosphatase was characterized from L. helveticus 2126 in this study. The purified bacterial phosphatase was subjected to mass spectrometric analysis, and the identity of constructed sequence was analyzed using peptide mass fingerprint. The 3-D structure of protein was elucidated using homology modeling, while its stability was assessed using Ramachandran plot, VERIFY 3D, and PROCHECK. The bacterium produced an extracellular phosphatase of zone diameter 15 ± 0.8 mm on screening medium within 24 h of incubation. This bacterial phosphatase was highly specific towards sodium phytate as it yielded the lowest Km value of 299.50 ± 4.95 μM compared to other phosphorylated substrates. The activity was effectively stimulated in the presence of zinc, magnesium, and manganese ions thereby showing its PTP-like behavior. The phosphatase showed a molecular mass of 43 kDa, and the corresponding M/Z ratio data yielded 46% query coverage to Bacillus subtilis (3QY7). This showed a 61.1% sequence similarity to Ligilactobacillus ruminis (WP_046923835.1). The final sequence construct based on these bacteria showed a conserved motif “HCHILPGIDD” in their active site. In addition, homology modeling showed a distorted Tim barrel structure with a trinuclear metal center. The final model after energy minimization showed 90.9% of the residues in the favorable region of Ramachandran’s plot. This structural information can be used in genetic engineering for improving the overall stability and catalytic efficiency of probiotic bacterial phosphatases.(AU)

Imbalanced metabolism induced NH4+ accumulation and its effect on the central metabolism of Methylomonas sp. ZR1 / El metabolismo desequilibrado indujo la acumulación de NH4+ y su efecto sobre el metabolismo central de Methylomonas sp. ZR1

Nitrogen and carbon are the two most essential nutrient elements, and their metabolism is tightly coupled in single carbon metabolic microorganisms. However, the nitrogen metabolism and the nitrogen/carbon (N/C) metabolic balance in single-carbon metabolism is poorly studied. In this study, the nitrogen metabolism pattern of the fast growing methanotrophs Methylomonas sp. ZR1 grown in methane and methanol was studied. Effect study of different nitrogen sources on the cell growth of ZR1 indicates that nitrate salts are the best nitrogen source supporting the growth of ZR1 using methane and methanol as carbon source. However, its metabolic intermediate ammonium was found to accumulate with high N/C ratio in the medium and consequently inhibit the growth of ZR1. Studies of carbon and nitrogen metabolic kinetic under different N/C ratio conditions indicate that the accumulation of NH4+ is caused by the imbalanced nitrogen and carbon metabolism in ZR1. Feeding carbon skeleton α-ketoglutaric acid could effectively relieve the inhibition effect of NH4+ on the growth of ZR1, which further confirms this assumption. qPCR analysis of the expression level of the central metabolic key enzyme gene indicates that the nitrogen metabolic intermediate ammonium has strong regulation effect on the central nitrogen and carbon metabolism in ZR1. qPCR-combined genomic analysis confirms that a third ammonium assimilation pathway glycine synthesis system is operated in ZR1 to balance the nitrogen and carbon metabolism. Based on the qPCR result, it was also found that ZR1 employs two strategies to relieve ammonium stress in the presence of ammonium: assimilating excess ammonium or cutting off the nitrogen reduction reactions according to the available C1 substrate. Validating the connections between single-carbon and nitrogen metabolism and studying the accumulation and assimilation mechanism of ammonium will contribute to understand how nitrogen regulates cellular growth in single-carbon metabolic microorganisms.(AU)

The abundance of comammox bacteria was higher than that of ammonia-oxidizing archaea and bacteria in rhizosphere of emergent macrophytes in a typical shallow lake riparian / La abundancia de bacterias comammox fue mayor que la de arqueas y bacterias oxidantes de amoníaco en la rizosfera de macrófitos emergentes en un típico lago ribereño poco profundo

Complete ammonia oxidation (comammox) bacteria can complete the whole nitrification process independently, which not only challenges the classical two-step nitrification theory but also updates long-held perspective of microbial ecological relationship in nitrification process. Although comammox bacteria have been found in many ecosystems in recent years, there is still a lack of research on the comammox process in rhizosphere of emergent macrophytes in lakeshore zone. Sediment samples were collected in this study from rhizosphere, far-rhizosphere, and non-rhizosphere of emergent macrophytes along the shore of Lake Liangzi, a shallow lake. The diversity of comammox bacteria and amoA gene abundance of comammox bacteria, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) in these samples were measured. The results showed that comammox bacteria widely existed in the rhizosphere of emergent macrophytes and fell into clade A.1, clade A.2, and clade B, and clade A was the predominant community in all sampling sites. The abundance of comammox amoA gene (6.52 × 106–2.45 × 108 copies g−1 dry sediment) was higher than that of AOB amoA gene (6.58 × 104–3.58 × 106 copies g−1 dry sediment), and four orders of magnitude higher than that of AOA amoA gene (7.24 × 102–6.89 × 103 copies g−1 dry sediment), suggesting that the rhizosphere of emergent macrophytes is more favorable for the growth of comammox bacteria than that of AOB and AOA. Our study indicated that the comammox bacteria may play important roles in ammonia-oxidizing processes in all different rhizosphere regions.(AU)

Biofouling inhibition by Staphylococcus aureus extracts and their potential use for paints / Inhibición de la bioincrustación por extractos de Staphylococcus aureus y su uso potencial para pinturas

For the control of biofouling, some paints based on compounds that are toxic to marine organisms have been used. There is an intensive search for biodegradable solutions that are friendly to non-target organisms. Bacteria have been shown to be a source of compounds with antifouling potential. In this work, the antifouling activity of a strain of Staphylococcus aureus was evaluated. Extracts activity against biofilm-forming bacteria and the toxicity against Artemia franciscana were evaluated. The extracts were incorporated in a hard gel and a paint matrix, and they were exposed to the sea. In both the laboratory and field, we found that the compounds produced by S. aureus have antifouling activity. The non-toxicity of the tested extracts against Artemia franciscana nauplii suggests that the extracts obtained from S. aureus could have a low ecological impact over non-target organisms. Significant differences were found in the percentage of organisms cover in hard gels with extracts and control. After 90 days, important differences were also observed between the percentage of organisms cover of the paints that contained extracts and the control. Dichloromethane extract is the most effective for the inhibition or delay of the settlement of organisms For this reason, they could be used in matrices with different applications, such as in the shipping industry, aquaculture, or any other in which biofouling is a cause of inconvenience.(AU)

C-terminus of serine–arginine protein kinase-like protein, SrpkF, is involved in conidiophore formation and hyphal growth under salt stress in Aspergillus aculeatus / El extremo C de la proteína similar a la serina-arginina proteína quinasa, SrpkF, participa en la formación de conidióforos y el crecimiento de hifas bajo estrés salino en Aspergillus aculeatus

The serine–arginine protein kinase–like protein, SrpkF, was identified as a regulator for the cellulose-responsive induction of cellulase genes in Aspergillus aculeatus. To analyze various aspects of SrpkF function, we examined the growth of the control strain (MR12); C-terminus deletion mutant, which produced SrpkF1–327 (ΔCsrpkF); whole gene-deletion mutant of srpkF (ΔsrpkF), srpkF overexpressing strain (OEsprkF); and the complemented strain (srpkF+) under various stress conditions. All test strains grew normally on minimal medium under control, high salt (1.5 M KCl), and high osmolality (2.0 M sorbitol and 1.0 M sucrose). However, only ΔCsrpkF showed reduced conidiation on 1.0 M NaCl media. Conidiation of ΔCsrpkF on 1.0 M NaCl media was reduced to 12% compared with that of srpkF+. Further, when OEsprkF and ΔCsrpkF were pre-cultured under salt stress conditions, germination under salt stress conditions was enhanced in both strains. By contrast, deletion of srpkF did not affect hyphal growth and conidiation under the same conditions. We then quantified the transcripts of the regulators involved in the central asexual conidiation pathway in A. aculeatus. The findings revealed that the expression of brlA, abaA, wetA, and vosA was reduced in ΔCsrpkF under salt stress. These data suggest that in A. aculeatus, SrpkF regulates conidiophore development. The C-terminus of SrpkF seems to be important for regulating SrpkF function in response to culture conditions such as salt stress.(AU)

Comparative genomics of Brucella abortus and Brucella melitensis unravels the gene sharing, virulence factors and SNP diversity among the standard, vaccine and field strains / La genómica comparada de Brucella abortus y Brucella melitensis revela el intercambio de genes, los factores de virulencia y la diversidad de SNP entre las cepas estándar, vacunales y de campo

Brucella abortus and Brucella melitensis are the primary etiological agents of brucellosis in large and small ruminants, respectively. There are limited comparative genomic studies involving Brucella strains that explore the relatedness among both species. In this study, we involved strains (n=44) representing standard, vaccine and Indian field origin for pangenome, single nucleotide polymorphism (SNP) and phylogenetic analysis. Both species shared a common gene pool representing 2884 genes out of a total 3244 genes. SNP-based phylogenetic analysis indicated higher SNP diversity among B. melitensis (3824) strains in comparison to B. abortus (540) strains, and a clear demarcation was identified between standard/vaccine and field strains. The analysis for virulence genes revealed that virB3, virB7, ricA, virB5, ipx5, wbkC, wbkB, and acpXL genes were highly conserved in most of the Brucella strains. Interestingly, virB10 gene was found to have high variability among the B. abortus strains. The cgMLST analysis revealed distinct sequence types for the standard/vaccine and field strains. B. abortus strains from north-eastern India fall within similar sequence type differing from other strains. In conclusion, the analysis revealed a highly shared core genome among two Brucella species. SNP analysis revealed B. melitensis strains exhibit high diversity as compared to B. abortus strains. Strains with absence or high polymorphism of virulence genes can be exploited for the development of novel vaccine candidates effective against both B. abortus and B. melitensis.(AU)