Spore-forming bacteria in gelatin: Characterization, identification by 16S rRNA and MALDI-TOF mass spectrometry (MS), and presence of heat resistance and virulence genes.

Gelatin, a versatile protein derived from collagen, is widely used in the food, pharmaceutical and medical sectors. However, bacterial contamination by spore-forming bacteria during gelatin processing represents a significant concern for product safety and quality. In this study, an investigation was carried out to explore the heat and chemical resistance, as well as the identification and characterization of spore-forming bacteria isolated from gelatin processing. The methodologies involved chemical resistance tests with drastic pH in microplates and thermal resistance tests in capillary tubes of various isolates obtained at different processing stages. In addition, phenotypic and genotypic analyses were carried out to characterize the most resistant isolates of spore-forming bacteria. The findings of this study revealed the presence of several species, including Bacillus cereus, Bacillus licheniformis, Bacillus sonorensis, Bacillus subtilis, Geobacillus stearothermophilus, and Clostridium sporogenes, with some isolates exhibiting remarkable chemical and heat resistances. In addition, a significant proportion of the most resistant isolates showed gelatinase activity (n = 19/21; 90.5 %) and the presence of heat resistance (n = 5/21; 23.8 %), and virulence genes (n = 11/21; 52.4 %). The results of this study suggest that interventions should be done in quality control practices and that process parameter adjustments and effective contamination reduction strategies should be implemented through gelatin processing.

Challenging fungal infections in cystic fibrosis: a case of mixed Aspergillus species infection and antifungal combination testing.

Aspergillus stands as the predominant fungal genus in the airways of cystic fibrosis (CF) patients, significantly contributing to their morbidity and mortality. Aspergillus fumigatus represents the primary causative species for infections, though the emergence of rare species within the Aspergillus section Fumigati has become noteworthy. Among these, Aspergillus lentulus is particularly significant due to its frequent misidentification and intrinsic resistance to azole antifungal agents. In the management of invasive aspergillosis and resistant infections, combination antifungal therapy has proven to be an effective approach. This report documents a case involving the death of a CF patient due to a pulmonary exacerbation linked to the colonization of multiple Aspergillus species, including A. lentulus, A. fumigatus, and A. terreus, and treated with Itraconazole (ITC) monotherapy. We delineated the procedures used to characterize the Aspergillus isolates in clinical settings and simulated in vitro the impact of the combination antifungal therapy on the isolates obtained from the patient. We evaluated three different combinations: Amphotericin B (AMB)+Voriconazole (VRC), AMB+Anidulafungin (AND), and VRC+AND. Notably, all strains isolated from the patient exhibited a significant decrease in their minimum inhibitory concentration (MIC) or minimum effective concentration (MEC) values when treated with all antifungal combinations. The VRC+AMB combination demonstrated the most synergistic effects. This case report emphasizes the critical importance of susceptibility testing and precise identification of Aspergillus species to enhance patient prognosis. It also underscores the potential benefits of combined antifungal treatment, which, in this case, could have led to a more favourable patient outcome.

Intranasal dexmedetomidine for sedation in ABR testing in children: No pain, big gain!

OBJECTIVES: Obtaining perfect immobility or sleep in children undergoing ABR auditory brainstem response) testing can be challenging. We examined the effectiveness and safety of intranasal dexmedetomidine for sedation of children undergoing ABR testing. MATERIAL AND METHODS: We included prospectively all patients aged from 1 to 15 years for whom sedation for ABR testing was required, between July 2018 and November 2021. We administered an initial dose of 2.5 µg/kg intranasal dexmedetomidine with a repeat dose of 1 µg/kg if needed 30 min later. Collected data included success rate of sedation, sedation onset and recovery times and incidence of side effects. RESULTS: ABR testing was undertaken successfully in 57 of the 59 patients, giving a total success rate of 96,6 %. (95 % confidence interval 88.5 %-99.1 %). The median time to onset of sleep was 32 ± 18.3 min. The median duration of sedation recovery time was 48 ± 24.7 min. We recorded the adverse effects. Thirty-one patients experienced bradycardia and 28 patients experienced hypotension, all of which resolved without intervention. CONCLUSION: Intranasal dexmedetomidine is an effective, safe, simple of use and noninvasive method for sedation in children. It could have a major role in auditory brainstem response testing, specially in the case of non-cooperative children. REGISTRATION NUMBER OF THE TRIAL: NCT03530371.

Uncovering a Novel cyp51A Mutation and Antifungal Resistance in Aspergillus fumigatus through Culture Collection Screening.

BACKGROUND: Aspergillus fumigatus is an important concern for immunocompromised individuals, often resulting in severe infections. With the emergence of resistance to azoles, which has been the therapeutic choice for Aspergillus infections, monitoring the resistance of these microorganisms becomes important, including the search for mutations in the cyp51A gene, which is the gene responsible for the mechanism of action of azoles. We conducted a retrospective analysis covering 478 A. fumigatus isolates. METHODS: This comprehensive dataset comprised 415 clinical isolates and 63 isolates from hospital environmental sources. For clinical isolates, they were evaluated in two different periods, from 1998 to 2004 and 2014 to 2021; for environmental strains, one strain was isolated in 1998, and 62 isolates were evaluated in 2015. Our primary objectives were to assess the epidemiological antifungal susceptibility profile; trace the evolution of resistance to azoles, Amphotericin B (AMB), and echinocandins; and monitor cyp51A mutations in resistant strains. We utilized the broth microdilution assay for susceptibility testing, coupled with cyp51A gene sequencing and microsatellite genotyping to evaluate genetic variability among resistant strains. RESULTS: Our findings reveal a progressive increase in Minimum Inhibitory Concentrations (MICs) for azoles and AMB over time. Notably, a discernible trend in cyp51A gene mutations emerged in clinical isolates starting in 2014. Moreover, our study marks a significant discovery as we detected, for the first time, an A. fumigatus isolate carrying the recently identified TR46/F495I mutation within a sample obtained from a hospital environment. The observed cyp51A mutations underscore the ongoing necessity for surveillance, particularly as MICs for various antifungal classes continue to rise. CONCLUSIONS: By conducting resistance surveillance within our institution's culture collection, we successfully identified a novel TR46/F495I mutation in an isolate retrieved from the hospital environment which had been preserved since 1998. Moreover, clinical isolates were found to exhibit TR34/L98H/S297T/F495I mutations. In addition, we observed an increase in MIC patterns for Amphotericin B and azoles, signaling a change in the resistance pattern, emphasizing the urgent need for the development of new antifungal drugs. Our study highlights the importance of continued monitoring and research in understanding the evolving challenges in managing A. fumigatus infections.

Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry azole susceptibility assessment in Candida and Aspergillus species.

BACKGROUND: Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) allows rapid pathogen identification and potentially can be used for antifungal susceptibility testing (AFST). OBJECTIVES: We evaluated the performance of the MALDI-TOF MS in assessing azole susceptibility, with reduced incubation time, by comparing the results with the reference method Broth Microdilution. METHODS: Resistant and susceptible strains of Candida (n = 15) were evaluated against fluconazole and Aspergillus (n = 15) against itraconazole and voriconazole. Strains were exposed to serial dilutions of the antifungals for 15 h. Microorganisms' protein spectra against all drug concentrations were acquired and used to generate a composite correlation index (CCI) matrix. The comparison of autocorrelations and cross-correlations between spectra facilitated by CCI was used as a similarity parameter between them, enabling the inference of a minimum profile change concentration breakpoint. Results obtained with the different AFST methods were then compared. FINDINGS: The overall agreement between methods was 91.11%. Full agreement (100%) was reached for Aspergillus against voriconazole and Candida against fluconazole, and 73.33% of agreement was obtained for Aspergillus against itraconazole. MAIN CONCLUSIONS: This study demonstrates MALDI-TOF MS' potential as a reliable and faster alternative for AFST. More studies are necessary for method optimisation and standardisation for clinical routine application.

Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry azole susceptibility assessment in Candida and Aspergillus species

BACKGROUND Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) allows rapid pathogen identification and potentially can be used for antifungal susceptibility testing (AFST). OBJECTIVES We evaluated the performance of the MALDI-TOF MS in assessing azole susceptibility, with reduced incubation time, by comparing the results with the reference method Broth Microdilution. METHODS Resistant and susceptible strains of Candida (n = 15) were evaluated against fluconazole and Aspergillus (n = 15) against itraconazole and voriconazole. Strains were exposed to serial dilutions of the antifungals for 15 h. Microorganisms' protein spectra against all drug concentrations were acquired and used to generate a composite correlation index (CCI) matrix. The comparison of autocorrelations and cross-correlations between spectra facilitated by CCI was used as a similarity parameter between them, enabling the inference of a minimum profile change concentration breakpoint. Results obtained with the different AFST methods were then compared. FINDINGS The overall agreement between methods was 91.11%. Full agreement (100%) was reached for Aspergillus against voriconazole and Candida against fluconazole, and 73.33% of agreement was obtained for Aspergillus against itraconazole. MAIN CONCLUSIONS This study demonstrates MALDI-TOF MS' potential as a reliable and faster alternative for AFST. More studies are necessary for method optimisation and standardisation for clinical routine application.

Serum Vitamin D Levels and Life-Threatening Respiratory Syncytial Virus Infection in Previously Healthy Infants.

BACKGROUND: 25-hydroxyvitamin D (VD) effects on lung function and immune-modulation might affect respiratory syncytial virus (RSV) infection outcomes. We aimed to assess VD levels on admission and their association with life-threatening RSV disease (LTD). METHODS: A prospective cohort study was conducted during 2017-2019. Previously healthy infants aged <12 months, hospitalized with a first episode of RSV infection, were enrolled. LTD was defined by need for intensive care and ventilatory support. Serum VD levels <20 ng/mL were categorized as deficient, and 20-29.9 ng/mL as insufficient. RESULTS: Of 125 patients studied, 73 (58%) were male. Median age was 4 months. Twenty-two patients developed LTD. No differences in viral load were seen between cases with LTD and controls (P = .94). Patients who developed LTD had significantly lower VD levels: median 18.4 ng/mL (IQR, 15.1-26.9 ng/mL) versus 31.7 ng/mL (IQR, 23.6-42.0 ng/mL), P < .001; 59% of infants with LTD had VD deficiency compared with 12% in those with better outcome. Multivariable regression analysis confirmed VD deficiency as a risk factor (odds ratio, 11.83; 95% confidence interval, 3.89-35.9; P < .001). CONCLUSIONS: These findings provide additional evidence for the development of strategies to prevent severe RSV infections.

Genetic Susceptibility to Life-threatening Respiratory Syncytial Virus Infection in Previously Healthy Infants.

BACKGROUND: Genetic background may be an important host determinant of respiratory syncytial virus (RSV) disease severity, but full characterization of susceptibility genes remains unclear. This study aimed to assess the presence of specific single-nucleotide polymorphisms (SNPs) in selected genes codifying for different components of the antiviral innate immune response, to determine their role for developing RSV life-threatening disease (LTD). METHODS: Prospective cohort study including previously healthy full-term infants hospitalized with a first RSV infection during 2017-2018. RSV detection, quantification and subgroup determination, and genotyping for SNPs in Toll-like receptor 4 (TLR4 rs4986790, rs4986791), Toll-like receptor 8 (TLR8 rs3761624), macrophage receptor with collagenous structure(MARCO rs1318645) and myxovirus resistance 1(MX1 rs469390) were performed by real-time polymerase chain reaction in nasopharyngeal aspirates obtained on admission. Patients with LTD were those admitted to the intensive care unit requiring ventilatory support. RESULTS: Seventy-five patients were studied, 15 (20%) developed LTD. Infants with concurrent SNPs in MX1 and TLR8, MARCO and TLR8 or MARCO, MX1 and TLR8 had an increased risk of developing LTD. Multivariable logistic regression analysis confirmed this significant association (odds ratio [OR] = 3.75, P = 0.046; OR = 3.92, P = 0.040; OR = 5.56, P = 0.010, respectively). No differences were seen in viral load of patients with LTD compared with those with better outcome (P = 0.737). In addition, no differences in viral load were seen in patients with the described high-risk SNPs compared with those without these polymorphisms. CONCLUSIONS: Life-threatening RSV infection in previously healthy infants was significantly associated with the presence of combined SNPs in MARCO, MX1 and TLR8.

Analysis of predisposing factors for complications of percutaneous tracheostomy.

Since the turn of the century, percutaneous tracheostomy (PT) has become an alternative to the classic open technique and is an elective procedure in intensive care units at most centers. We conducted a prospective study to identify and quantify the complication rate with PT and to analyze this procedure's association with potential risk factors. Our study population was made up of 114 patients-83 men (72.8%) and 31 women (27.2%), aged 18 to 81 years (mean: 57 ± 15)-who underwent PT at our center over an 18-month period. We sought to determine if there were any associations between PT complications and sex, previous fibroscopy, cervical length, cervical risk factors, and general risk factors. Generally minor complications were noted in 15 patients (13.2%); 13 patients experienced hemorrhage, 1 exhibited subcutaneous emphysema, and 1 had a vagal reaction that resolved with medical treatment. Only 3 of these cases (2.6%) were considered to be clinically relevant: 1 hemorrhage (which was treated with ligation), the emphysema (which resolved spontaneously), and the vagal reaction (which resolved with medical treatment). Statistically, we found that PT complications were significantly correlated with two factors: coagulopathy (p = 0.015) and hemodynamic instability (p = 0.017). Even so, these complications were not clinically significant, and they resolved with conservative treatment measures. Given the low incidence and mild degree of these complications, we consider PT to be a safe procedure, even in patients with a high risk of hemorrhage or cervical anatomic difficulties.

Resultados en el tratamiento quirúrgico de los neurinomas del acústico gigantes / Results in the surgical treatment of giant acoustic neuromas

Introducción y objetivos: Comparar los resultados obtenidos en la resección de 21 schwanomas vestibulares gigantes, mediante vía retrosigmoidea y combinada retrosigmoidea/translaberíntica en cuanto a complicaciones intra y postoperatorias, preservación del nervio facial y secuelas posquirúrgicas. Métodos: Se realiza un estudio retrospectivo de 21 pacientes a los que se practicó resección de neurinoma vestibular gigante según la escala de Tos & Thomsen (igual o mayor a 4cm), en un hospital de tercer nivel en el periodo entre 2000 y 2008. Se presentan las características más significativas de la serie estudiada, y se analizan las ventajas e inconvenientes de los distintos abordajes, comparando los resultados obtenidos. Asimismo, se analizan los resultados en cuanto a la preservación de la función del nervio facial. Resultados: Destaca la ausencia de mortalidad en el grupo de 21 pacientes estudiado. No hubo complicaciones intraoperatorias importantes. Se consiguió la resección total de la lesión en el 87% de los casos, con una preservación anatómica del nervio facial del 73% en el abordaje combinado retrosigmoideo/translaberíntico, respecto a un 40% en el retrosigmoideo. La función del nervio facial a los dos años fue aceptable o buena en un 67% (incluyendo los resultados de las anastomosis heteronerviosas). Se observó un porcentaje global del 14,3% de fístula de líquido cefalorraquídeo y un 9,5% de meningitis. Conclusiones: nuestros resultados demuestran que el abordaje combinado retrosigmoideo translaberíntico para el tratamiento de schwannomas gigantes ofrece mayor preservación del nervio facial y disminución de la morbilidad, siendo una importante opción en el tratamiento de estos tumores, gracias a un enfoque multidisciplinar(AU)

Introduction and objectives: To compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. Methods: This was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4 centimetres) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. Results: We highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. Conclusions: The results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach(AU)

[Results in the surgical treatment of giant acoustic neuromas]. / Resultados en el tratamiento quirúrgico de los neurinomas del acústico gigantes.

INTRODUCTION AND OBJECTIVES: To compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. METHODS: This was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4 centimetres) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. RESULTS: We highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. CONCLUSIONS: The results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach.