A forced aeration system for microbial culture of multiple shaken vessels suppresses volatilization.

Shake-flask culture, an aerobic submerged culture, has been used in various applications involving cell cultivation. However, it is not designed for forced aeration. Hence, this study aimed to develop a small-scale submerged shaking culture system enabling forced aeration into the medium. A forced aeration control system for multiple vessels allows shaking, suppresses volatilization, and is attachable externally to existing shaking tables. Using a specially developed plug, medium volatilization was reduced to less than 10%, even after 45 h of continuous aeration (~ 60 mL/min of dry air) in a 50 mL working volume. Escherichia coli IFO3301 cultivation with aeration was completed within a shorter period than that without aeration, with a 35% reduction in the time-to-reach maximum bacterial concentration (26.5 g-dry cell/L) and a 1.25-fold increase in maximum concentration. The maximum bacterial concentration achieved with aeration was identical to that obtained using the Erlenmeyer flask, with a 65% reduction in the time required to reach it.

Application of BactTiter-Glo ATP bioluminescence assay for Mycobacterium tuberculosis detection.

BACKGROUND: Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), remains a global health threat, necessitating faster and more accessible diagnostic methods. This study investigates critical parameters in the application of a commercial ATP bioluminescence assay for the detection of MTB. METHOD: Our objective was to optimize the ATP bioluminescence protocol using BacTiter-Glo™ for MTB, investigating the impact of varying volumes of MTB suspension and reagent on assay sensitivity, evaluating ATP extraction methods, establishing calibration curves, and elucidating strain-specific responses to antimicrobial agents. RESULTS: ATP extraction methods showed no significant improvement over controls. Calibration curves revealed a linear correlation between relative light units (RLU) and colony-forming units (CFU/mL), establishing low detection limits. Antimicrobial testing demonstrated strain-specific responses aligning with susceptibility and resistance patterns. CONCLUSION: Our findings contribute to refining ATP bioluminescence protocols for enhanced MTB detection and susceptibility testing. Further refinements and validation efforts are warranted, holding promise for more efficient diagnostic platforms in the future.

The use of Kudoh method for culture of Mycobacterium tuberculosis and Mycobacterium africanum in The Gambia.

BACKGROUND: Mycobacterium tuberculosis culturing remains the gold standard for laboratory diagnosis of tuberculosis. Tuberculosis remains a great public health problem in developing countries like The Gambia, as most of the methods currently used for bacterial isolation are either time-consuming or costly. OBJECTIVE: To evaluate the Kudoh swab method in a West African setting in Gambia, with a particular focus on the method's performance when culturing Mycobacterium africanum West Africa 2 (MAF2) isolates. METHOD: 75 sputum samples were collected in the Greater Banjul Area and decontaminated in parallel with both the standard N-acetyl-L-Cysteine-NaOH (NALC-NaOH) and the Kudoh swab method in the TB diagnostics laboratory in the Medical Research Council Unit The Gambia between 30th December 2017 and 25th February 2018. These samples were subsequently cultured on standard Löwenstein-Jensen and Modified Ogawa media respectively and incubated at 37°C for mycobacterial growth. Spoligotyping was done to determine if the decontamination and culture methods compared could equally detect Mycobacterium tuberculosis, Mycobacterium africanum West Africa 1 and Mycobacterium africanum West Africa 2. RESULT: Among the 50 smear positives, 35 (70%) were culture-positive with Kudoh and 32 (64%) were culture positive with NALC-NaOH, whilst 7(28%) of the 25 smear negative samples were culture positive with both methods (Table 2). There was no significant difference in recovery between both methods (McNemar's test, p-value = 0.7003), suggesting that the overall positivity rate between the two methods is comparable. There were no differences in time-to-positivity or contamination rate between the methods. However, Kudoh yielded positive cultures that were negative on LJ and vice versa. All findings were irrespective of mycobacterial lineages. CONCLUSION: The Kudoh method has comparable sensitivity to the NALC-NaOH method for detecting Mycobacterium tuberculosis complex isolates. It is easy to perform and could be an add on option for mycobacterial culture in the field in The Gambia, since it requires less biosafety equipment.

Recovery rates of mycobacterium from suspected extra-pulmonary tuberculosis patients using liquid culture at a tertiary referral centre of India.

Tuberculosis still remains a serious public health problem in developing countries. Rapid isolation of mycobacteria is critical for accurate diagnosis and management of tuberculosis. In the present study BACTEC MGIT 960 system was evaluated against Lowenstein Jensen (LJ) medium for isolation of mycobacteria from different extra-pulmonary specimens (N = 371). The samples were processed using NaOH-NALC method and inoculated in BACTEC MGIT and on LJ medium. The BACTEC MGIT 960 system detected 93 (25.06%) samples positive for acid fast bacilli and by LJ only 38 samples (10.24%) was positive. Furthermore, total 99 (26.68%) samples were detected positive by both the culture methods. The mean turnaround time to detection of mycobacteria by MGIT 960 were significantly less (12.4 days) as compared with LJ (22.76 days). In conclusion, BACTEC MGIT 960 system is more sensitive and rapid culture system for isolation of mycobacteria. However LJ culture method also suggested to further increase the detection rate of EPTB cases.

Proof of concept for multiplex detection of antibodies against Chlamydia species in chicken serum using a bead-based suspension array with peptides as antigens.

The available differentiating tests for Chlamydia are based on detection of genetic material and only give information about the actual infection status, but reveal nothing of past infections. As the use of serological methods increases the window of detection, the goal of this study was to investigate if it is possible to develop a differentiating serological test for antibodies against Chlamydia species in chicken sera. Focus was on C. psittaci, C. gallinacea, and two closely related species, i.e. C. abortus and C. avium. To enable differentiating serology, a bead-based Luminex suspension array was constructed, using peptides as antigens, derived from known immunoreactive Chlamydia proteins. For the majority of these peptides, species-specific seroreactivity in mammalian sera has been reported in literature. The suspension array correctly identified antibodies against various Chlamydia species in sera from experimentally infected mice, and was also able to differentiate between antibodies against C. psittaci and C. gallinacea in sera from experimentally infected chickens. In field sera, signals were difficult to interpret as insufficient sera from experimentally infected chickens were available for evaluating the seroreactivity of all peptides. Nevertheless, results of the suspension array with field sera are supported by published data on the occurrence of C. gallinacea in Dutch layers, thereby demonstrating the proof of concept of multiplex serology for Chlamydial species in poultry.

Eficácia in sílico do florfenicol no tratamento de pododermatite infecciosa por Fusobacterium necrophorum em ovelhas / In sílico efficacy of florfenicol in the treatment of Fusobacterium necrophorum infectious pododermatitis in sheep

Objetivou-se comparar o efeito in silico do florfenicol nas doses de 20 e 30 mg/Kg em ovinos pelas vias intravenosa (IV) e intramuscular (IM), usando a modelagem PK/PD. Realizou-se uma simulação de Monte Carlo com base nos dados de concentração plasmática de um estudo publicado anteriormente. Calculou-se a área sob a curva (ASC) e as taxas de eficácia do florfenicol para os efeitos bacteriostático, bactericida e de erradicação bacteriológica. A dose de 20 mg/Kg IV demonstrou efeitos de erradicação de 100, 93 e 0% para CIM de 0,5, 1 e acima, respectivamente. O efeito bacteriostático foi de 99 e 90% para CIM de 4 e 2 µg/ml, enquanto o bactericida foi de 14% para CIM de 2 µg/ml. A dose de 30 mg/Kg IV apresentou 100% de erradicação para CIM de 1 µg/mL e 100% de efeito bactericida para CIM de 2 µg/mL. Há 100% de efeito bacteriostático em CIM de 4 µg/ml. As doses de 20 e 30 mg/Kg IM mostraram 100% de erradicação para CIM até 1 µg/mL e 0% para CIM maiores. O efeito bacteriostático foi mantido em 100% para uma CIM de 4 µg/mL em ambas as doses. Este estudo mostra o efeito de erradicação bacteriológica do florfenicol nas doses de 20 e 30 mg/Kg, IV e IM. Recomenda-se que seja feito um estudo de eficácia in vivo com a dose de 30mg/Kg IM em ovinos infectados por F. necrophorum com MIC superior a 2 µg/mL.

We aimed to compare the in silico effect of florfenicol at doses of 20 and 30 mg/Kg in sheep by intravenous (IV) and intramuscular (IM) routes, using PK/PD modeling. We performed a Monte Carlo simulation based on plasma concentration data from a previously published study. We calculated the area under the curve (AUC) and the efficacy rates of florfenicol to bacteriostatic, bactericidal, and bacteriological eradication effects. The dose of 20 mg/Kg IV demonstrated 100, 93, and 0% eradication effects for MICs of 0.5, 1, and above, respectively. The bacteriostatic effect was 99 and 90% for MIC of 4 and 2 µg/ml, while the bactericide was 14% for MIC of 2 µg/ml. The 30 mg/Kg IV dose showed 100% eradication for MIC of 1 µg/mL and 100% bactericidal effect for MIC of 2 µg/mL. There is a 100% of bacteriostatic effect at MIC of 4 µg/ml. Doses of 20 and 30 mg/Kg IM showed 100% eradication for MIC up to 1 µg/mL and 0% for MIC above. The bacteriostatic effect was maintained at 100% for a MIC of 4 µg/mL at both doses. This study shows the bacteriological eradication effect of florfenicol at doses of 20 and 30 mg/Kg, IV, and IM. Therefore, we recommend an in vivo efficacy study with a dose of 30mg/Kg IM in sheep infected with F. necrophorum with MIC greater than two µg/mL.

Diagnóstico bacteriológico de la tuberculosis. Estado actual del conocimiento Primera parte / Bacteriologic Diagnosis of Tuberculosis. Current State of Knowledge First part

Uno de los principales desafíos para los Programas de Control de Tuberculosis (PCT) lo constituye la detección temprana de formas abiertas de la enfermedad. La Organización Mundial de la Salud (OMS) ha estimado que el desarrollo de un método de diagnóstico de tuberculosis (TB) que ofreciera un 85% de sensibilidad y un 95% de especificidad sobre muestras de esputo permitiría salvar unas 400000 vidas al año. En condiciones ideales, sería necesario, además, que un método accesible y preciso, aplicado en colectivos de mayor vulnerabilidad, pudiera aportar tanto a la identificación de especie como a su perfil de resistencia, en especial si este implicara un mayor riesgo de fracaso terapéutico. En la última década, el desarrollo del sistema de diagnóstico GeneXpert MTB/RIF ha significado un gran avance en ese sentido. A un costo de USD 9,98 por determinación (en los 145 países subsidiados), el método permitió acercarse a los objetivos mencionados, es decir, la detección precoz de la TB y la detección de resistencia a rifampicina, usualmente tomada como un indicador de fracaso terapéutico.

Caracterización clínica y microbiológica de pacientes con trazas en Xpert MTB/RIF Ultra / Clinical and microbiological characterization of patients with Xpert MTB/RIF Ultra traces

INTRODUCCIÓN: El Xpert MTB/RIF Ultra (Ultra) ha mejorado dramáticamente el diagnóstico de la tuberculosis (TBC). Con él ha nacido la categoría de trazas, que es la menor carga bacilar detectable por este examen. OBJETIVO: Describir las características clínicas de los pacientes con presencia de trazas en el Ultra y evaluar la confirmación de la TBC como diagnóstico clínico. MATERIALES Y MÉTODOS: Estudio descriptivo de serie de casos. Se extrajo la información de fichas clínicas de pacientes con positividad a trazas. Se confrontaron datos clínicos, microbiológicos e histopatológicos. RESULTADOS: Se analizaron 21 pacientes. La edad promedio fue de 52 años. Todos los casos presentaron baciloscopias negativas. Cuatro cultivos en medio líquido MGIT fueron positivos, dos en pleura parietal, uno en líquido pleural y otro en expectoración. En pleura parietal, tres casos presentaron granulomas con necrosis caseosa y un granuloma esbozos de necrosis. En tejido pulmonar se observaron dos casos con granulomas con esbozos de necrosis y dos con granulomas no necrotizantes. Tres pacientes tenían el antecedente de TBC previa, se interpretó la positividad de trazas en ellos como falsos positivos. Finalmente se diagnosticaron 13 casos como TBC activa, donde cinco de ellos fueron TBC pleurales. La mayor concordancia clínica, microbiológica e histopatológica fue en muestras de líquido y tejido pleural. DISCUSIÓN: Se debe interpretar con cautela los hallazgos de esta prueba en muestras de vía aérea; el análisis multidisciplinario (clínica, imágenes, microbiología, histología) es crucial en las decisiones de nuestras conductas clínicas futuras. El hallazgo de trazas en pleura tiene, a nuestro parecer, un alto valor diagnóstico en el estudio de la tuberculosis en esta localización.

INTRODUCTION: Xpert MTB/RIF Ultra has dramatically changed the diagnosis of tuberculosis. A new category called traces appeared, which is the smallest amount of bacillar load detectable. OBJECTIVE: Describe the clinical characteristics of patients that present traces in Xpert MTB/RIF Ultra test, and to evaluate the confirmation of tuberculosis as clinical diagnosis. METHODS: We perform a descriptive case series study. Information was recovered from clinical records of patients with positive test for traces. Clinical, histopathological and microbiological results were confronted. RESULTS: Twenty one patients were analyzed. The mean age was 52 years-old. All cases had negative smear microscopy and four MGIT cultures were positive, two in pleural fluid and another in sputum. In parietal pleura, three cases presented granulomas with caseous necrosis, and one showed granuloma with very little necrosis. In pleural tissue we observed two cases of granulomas with traces of necrosis and two with non-necrotizing granulomas. Three patients had history of previous tuberculosis and positive traces, the test was interpreted as a false positive result. Finally, active tuberculosis was diagnosed in 13 cases, and five of them were pleural tuberculosis. The highest clinical, microbiological and histopathological agreement was in fluid and pleural tissue samples. DISCUSSION: The findings of Xpert MTB/RIF Ultra in airway samples must be interpreted carefully. Multi-disciplinary analysis is crucial in future clinical decisions. The finding of traces in pleura has, in our opinion, a high diagnostic value in the study of tuberculosis in this location.

Métodos diagnósticos para tuberculose: uma revisão integrativa / Diagnostic methods for tuberculosis: an integrative review

A tuberculose é doença muito prevalente, com 5,8 milhões de casos ao ano, podendo apresentar padrão multissistêmico de acometimento, sendo mais comum a forma pulmonar. Objetivo: Revisão de literatura acerca dos métodos existentes de diagnóstico da tuberculose, focada em suas eficácias. Método: Foi realizada revisão integrativa por meio de publicações de 2016 a 2022 obtidas na base de dados PubMed e Scielo. Foram usados os descritores: Mycobacterium tuberculosis AND diagnosis. Foram obtidos 14 artigos que satisfizeram os critérios de inclusão. Resultado: Das formas de diagnóstico existem exames de imagem (Raio-X e tomografia computadorizada), baciloscopia, cultura e moleculares. Conclusão: Os métodos por imagem têm relevância quando seus achados são correlacionados com a clínica e podem auxiliar no diagnóstico. Nos métodos bacteriológicos, o sistema do GeneXpert Ultra apresenta maior custo-benefício, com valores de sensibilidade e especificidade altos - acima de 90% - superior à baciloscopia, e com menor tempo para realização em comparação com a cultura

nd may present a multisystem pattern of involvement, with the pulmonary form being the most common. Objective: Literature review on existing methods used to diagnose tuberculosis. Method: An integrative review was carried out through publications from 2016 to 2022 in the PubMed and Scielo publication database. The descriptors were used: Mycobacterium tuberculosis AND diagnosis. Fourteen articles that met the inclusion criteria were obtained. Result: Among the ways of diagnosing tuberculosis, there are imaging tests (X-ray and computed tomography), bacilloscopy, culture and molecular tests. Conclusion: Imaging methods have their findings correlated and can aid in the diagnosis. In bacteriological methods, the GeneXpert Ultra system is cost-effective, with high sensitivity and specificity values - above 90% -, superior to bacilloscopy, with a shorter time to perform compared to culture

Wooden sticks for plaque streaking and microbiological inoculation might be more cost- effective, but is its large scale use feasible? Quality control methods and proof of concept / Métodos de controle de qualidade e prova de conceito para a utilização de palitos de madeira em microbiologia podem ser mais econômicas, mas seu uso em larga escala é viável? Método de controle de qualidade e prova de conceito

The loop is a material classically used in the laboratory for the purpose of plate streaking and handling biological materials. However, metal loops techniques might be time consuming, considering the amount of time spent to guarantee its cooling process through each inoculation. Furthermore, plastic loops may also represent environmental issues during its production and discard process and can also represent higher costs for the laboratory. Thus, in situations of limited resources, even the simplest materials can be restricted due to logistical and budgetary issues, especially in developing countries. Inspired by demands like these, facing an occasional shortage of supply of laboratory plastic handles, we hereby present a quality control for sterilization methods and cost-effectiveness studies towards the use of wooden sticks in a Latin American country and we discuss the possibility of the large-scale use of this technique.

A alça calibrada é um material usado classicamente em laboratório para fins de inoculação em placas e manuseio de materiais biológicos. No entanto, as técnicas de alças metálicas podem consumir muito tempo, considerando a quantidade de tempo gasto para garantir seu processo de resfriamento a cada inoculação. Além disso, alças de plástico também podem representar questões ambientais durante o processo de produção e descarte e também podem representar custos mais altos para o laboratório. Assim, em situações de recursos limitados, até os materiais mais simples podem ser restringidos devido a questões logísticas e orçamentárias, especialmente nos países em desenvolvimento. Inspirados por demandas como essas, diante de uma escassez ocasional de suprimentos de alças de plástico de laboratório, apresentamos um controle de qualidade para métodos de esterilização e estudos de custo-efetividade para o uso de varas de madeira em um país latino-americano e discutimos a possibilidade de grande uso em escala dessa técnica.

Evaluación fisicoquímica y bacteriológica del agua del río chillón / Physicochemical and bacteriological evaluation of the Chillón river water

El agua es uno de los compuestos más importantes y abundantes del ecosistema. Todos los organismos vivos de la tierra necesitan agua para su supervivencia y crecimiento. Hasta ahora, sólo La Tierra es el único planeta que tiene alrededor del 70% de agua, pero de ella sólo un muy pequeño porcentaje (0,3%) es apta para el consumo humano. Adicionalmente, el aumento de la demanda de agua como consecuencia de la población crecimiento, agricultura y desarrollo industrial ha obligado a los ambientalistas a determinar las características químicas, físicas y biológicas de los recursos hídricos naturales. La calidad de los recursos hídricos depende en gran medida de parámetros físico-químicos y características biológicas. Evaluar el monitoreo de estos parámetros es esencial para identificar la magnitud y la fuente de cualquier carga contaminante. Estas características pueden identificar cierta condición para la ecología de los organismos vivos y sugerir estrategias apropiadas de conservación y manejo. La disponibilidad de agua de buena calidad es una característica indispensable para prevenir enfermedades y mejorar calidad de vida. En este artículo se evaluó la calidad del agua, desde el punto de vista fisicoquímico y bacteriológico del río Chillón ubicado a 130 km del sur de la ciudad de Lima, Perú. Los resultados concluyeron que el río Chillón, especialmente, aguas abajo, no cumple con los estándares de calidad establecidos según normativa. El cálculo de ICARHS fue de 35,40, lo que categoriza al río Chillón con aguas de pésima calidad. Con los resultados obtenidos, se recomienda a las autoridades e instituciones gubernamentales el apoyo a continuar con el monitoreo de aguas de los ríos como una herramienta eficaz para evaluar su estado ecológico, así como para la protección de su contaminación y de la salud humana(AU)

Water is one of the most important and abundant compounds in the ecosystem. All living organisms on earth need water for their survival and growth. Until now, only the Earth is the only planet that has about 70% water, but of it only a very small percentage (0.3%) is suitable for human consumption. Additionally, the increased demand for water as a result of population growth, agriculture, and industrial development has forced environmentalists to determine the chemical, physical, and biological characteristics of natural water resources. The quality of water resources depends largely on physical-chemical parameters and biological characteristics. Evaluating the monitoring of these parameters is essential to identify the magnitude and source of any contaminant load. The availability of good quality water is an essential feature to prevent diseases and improve quality of life. In this article, the quality of the water was evaluated from the physicochemical and bacteriological point of view of the Chillón River located 130 km south of the city of Lima, Peru. The results concluded that the Chillón River, especially downstream, does not meet the quality standards established according to regulations. The ICARHS calculation was 35.40, which categorizes the Chillón River as having poor quality water. With the results obtained, it is recommended that government authorities and institutions support the continuation of river water monitoring as an effective tool to assess their ecological status, as well as to protect against contamination and human health(AU)

Genome-wide analysis of fitness-factors in uropathogenic Escherichia coli during growth in laboratory media and during urinary tract infections.

Uropathogenic Escherichia coli (UPEC) UTI89 is a well-characterized strain, which has mainly been used to study UPEC virulence during urinary tract infection (UTI). However, little is known on UTI89 key fitness-factors during growth in lab media and during UTI. Here, we used a transposon-insertion-sequencing approach (TraDIS) to reveal the UTI89 essential-genes for in vitro growth and fitness-gene-sets for growth in Luria broth (LB) and EZ-MOPS medium without glucose, as well as for human bacteriuria and mouse cystitis. A total of 293 essential genes for growth were identified and the set of fitness-genes was shown to differ depending on the growth media. A modified, previously validated UTI murine model, with administration of glucose prior to infection was applied. Selected fitness-genes for growth in urine and mouse-bladder colonization were validated using deletion-mutants. Novel fitness-genes, such as tusA, corA and rfaG; involved in sulphur-acquisition, magnesium-uptake, and LPS-biosynthesis, were proved to be important during UTI. Moreover, rfaG was confirmed as relevant in both niches, and therefore it may represent a target for novel UTI-treatment/prevention strategies.

Guided Aspiration for Determining the Microbiological Aetiology of Aortic Vascular Graft and Endograft Infections.

OBJECTIVE: Open and endovascular aortic repair may be complicated by aortic vascular graft or endograft infection (VGEI). Confirming the microbiological aetiology is a key element in providing the best available treatment to patients with a VGEI. The primary aim of this study was to describe the technique of direct aneurysm sac guided aspiration (DASGA) in determining the microbiological aetiology in a cohort of patients with VGEIs, and to report its diagnostic value. METHODS: This was a retrospective observational single centre study performed between the years 2011 to 2020 in Malmö, Sweden. Patients with a suspected aortic VGEI, where a DASGA was performed at the Vascular Centre, were included in the study. RESULTS: In total, 31 guided aspirations were performed in 27 patients (25 male [93%]; median age 77 years [range 57 - 82 years]). The combination of culture and 16S rRNA/18S rRNA gave a microbial aetiology in 25/31 (81%) DASGAs. Importantly, excluding three cases where infection was ruled out, this rate increases up to 89%. A polymicrobial aetiology was found in six (24 %) cases. The most common bacteria found were Cutibacterium spp. (n = 8) and Listeria monocytogenes (n = 4). In total, the dominant aetiology could be further characterised into normal gut flora (n = 12; 48%) or skin commensals (n = 8; 32%). No patients had persistent morbidity related to the DASGA. CONCLUSION: DASGA can be used successfully to determine the microbiological aetiology of open and endovascular graft infections. This method appears to be safe, with a high success rate for confirming the microbiological aetiology of VGEIs, particularly if standard culturing methods are combined with 16S rRNA/18S rRNA. Finding the causative microbial aetiology is crucial, and in the vast majority of cases translumbar puncture can be used without serious complications.

Clinical Significance of Toxigenic Clostridioides difficile Growth in Stool Cultures during the Era of Nonculture Methods for the Diagnosis of C. difficile Infection.

The importance of the detection of relevant toxins or toxin genes to diagnose Clostridioides difficile infection (CDI) or the prediction of clinical outcomes of CDI has been emphasized in recent years. Although stool culture of C. difficile is not routinely recommended in the era of nonculture methods as the preferred tools for CDI diagnosis, the clinical significance of toxigenic C. difficile growth (tCdG) in stool cultures was analyzed. A clinical study was conducted in medical wards of Tainan Hospital, Ministry of Health and Welfare, in southern Taiwan. Diarrheal adults with fecal glutamate dehydrogenase and C. difficile toxin between January 2013 and April 2020 were included. Of the 209 patients with CDI, 158 (75.6%) had tCdG found in stool cultures, and the rest (51, 24.4%) had no tCdG in stool. Only prior ceftazidime or ceftriaxone therapy was independently associated with no tCdG in stool (odds ratio [OR] 2.17, P = 0.02). Compared to the patients with tCDG in stool, those without tCdG in stool experienced treatment success more often (97.1% versus 67.0%, P < 0.001) if treated with metronidazole or vancomycin but had a similar in-hospital mortality or recurrence rate. In the multivariate analysis among 114 patients with CDI treated with metronidazole or vancomycin, treatment success was independently associated with no tCdG in stool (OR 12.7, P = 0.02). Despite the limited utility of stool cultures in CDI diagnoses, no tCdG in stool culture heralds a favorable therapeutic outcome among adults with CDI treated with metronidazole or vancomycin. IMPORTANCE The importance of detecting toxins or toxin genes when diagnosing Clostridioides difficile infections (CDIs) or predicting the severity and outcomes of CDI has been emphasized in recent years. Although the yielding of C. difficile from stool cultures might implicate higher bacterial loads in fecal samples, in an era of nonculture methods for the standard diagnosis of CDIs, clinical significance of positive stool cultures of toxigenic C. difficile was analyzed in this study. Despite the limited ability of stool cultures in CDI diagnoses, no yielding of C. difficile growth might predict the successful CDI therapy.

Mold in Foam Pillows and Mattresses: A Novel Cause of Hypersensitivity Pneumonitis.

Hypersensitivity pneumonitis (HP) is an inflammatory and/or fibrotic disease affecting the lung parenchyma and small airways. It typically results from an immune-mediated reaction provoked by an overt or occult inhaled antigen in susceptible individuals. The chronic or fibrotic form of HP has a poor prognosis, especially when no inciting antigen is identified, which occurs in up to 60% of cases. We report two cases of HP associated with exposure to mold in foam pillows and a mattress, which has not previously been reported as a risk factor for HP. Given the high prevalence of foam in pillows and mattresses, mold in foam in bedding may explain many HP cases with a previously unrecognized cause. Early identification and avoidance of foam in bedding may prevent HP progression to end-stage pulmonary fibrosis and death.

Bacterial Enrichment Cultures Biotransform the Mycotoxin Deoxynivalenol into a Novel Metabolite Toxic to Plant and Porcine Cells.

The mycotoxin deoxynivalenol (DON), produced in wheat, barley and maize by Fusarium graminearum and Fusarium culmorum, is threatening the health of humans and animals. With its worldwide high incidence in food and feed, mitigation strategies are needed to detoxify DON, maintaining the nutritional value and palatability of decontaminated commodities. A promising technique is biological degradation, where microorganisms are used to biotransform mycotoxins into less toxic metabolites. In this study, bacterial enrichment cultures were screened for their DON detoxification potential, where DON and its potential derivatives were monitored. The residual phytotoxicity was determined through a bioassay using the aquatic plant Lemna minor L. Two bacterial enrichment cultures were found to biotransform DON into a still highly toxic metabolite for plants. Furthermore, a cytotoxic effect was observed on the cellular viability of intestinal porcine epithelial cells. Through liquid chromatography high-resolution mass spectrometry analysis, an unknown compound was detected, and tentatively characterized with a molecular weight of 30.0 Da (i.e., CH2O) higher than DON. Metabarcoding of the subsequently enriched bacterial communities revealed a shift towards the genera Sphingopyxis, Pseudoxanthomonas, Ochrobactrum and Pseudarthrobacter. This work describes the discovery of a novel bacterial DON-derived metabolite, toxic to plant and porcine cells.

A simple, efficient and cost-effective method for medium- to longterm maintenance and storage of Mycobacterium abscessus complex organisms.

Traditional culture of non-tuberculous mycobacteria (NTMs) has involved egg-based formulations (Lowenstein-Jensen medium, Ogawa Egg medium) or defined media (Middlebrook formulations), which have disadvatages of composition complexity, availability and cost. Previously, the commercial agar formulation, Standard Plate Count (SPC) agar [Yeast extract 2.5 g/L, pancreatic digest of casein 5.0 g/L, glucose 1.0 g/L, agar 15.0 g/L, pH 7.0 ± 0.2 at 25 °C] has been shown to be an effective solid medium for the enumeration and laboratory manipulation of Mycobacterium abscessus complex organisms. Given its relative simplicity, commercial availability and inexpensive cost, we wished to evaluate its utility for the medium- to longterm maintenance/storage of these organisms. M. abscessus complex organisms (n = 33), were inoculated onto SPCA slopes and stored undistubed in the dark at ambient temperature for six months. Following this, slopes were broken out and culture of the NTM attempted. All slopes maintained NTM culture viability and were able to initiate growth six months later. We therefore advocate the cost-effective employment of SPCA slopes for the medium- to longterm maintenance of M. abscessus organisms, without the need for complex media, availability of sterile blood and requirements for continuous -80 °C freezing.

Development and validation of an improved method for the detection of Salmonella in cinnamon bark and oregano leaves using the adsorbent beta zeolite in the pre-enrichment media.

The detection of Salmonella in spices is challenging due to the presence of antibacterial components. In this study, we evaluated the use of an adsorbent beta zeolite in pre-enrichment media to improve the recovery of Salmonella from cinnamon bark and oregano leaves. Samples (25 g) were spiked with varying levels of S. Montevideo or S. Senftenberg. After 2 weeks of stabilization at RT, betazeolite was added to cinnamon and oregano samples prior to the addition of 225 mL or 475 mL of pre-enrichment media, respectively. Detection sensitivity and rate of the test method were compared to the FDA Bacteriological Analytical Manual (BAM) method which requires the use of 2.5 L pre-enrichment broth. While Salmonella could not be detected in the test method using the reduced volume of pre-enrichment media alone, the addition of beta zeolite resulted in a positivity rate of 62% and 72.6% for cinnamon bark and oregano leaves respectively (all spike levels and both serovars combined). Furthermore, while there were differences in the LOD50 compared to the BAM method, there was no significant difference in the minimum level of detection between the betazeolite and the BAM methods. Our results demonstrate that the use of betazeolite in the pre-enrichment media offers a method with reduced media volumes without compromising on the sensitivity or efficiency of Salmonella detection in cinnamon bark and oregano leaves.

Viability assessment of Mycobacterium tuberculosis complex in OMNIgene • SPUTUM reagent using the BACTEC MGIT 960 System and Xpert MTB/RIF assay.

The World Health Organization advocates that sputum specimens submitted to tuberculosis (TB) diagnostic should be processed within 48 h after collection and be stored under cooling. We aimed to assess the performance of OMNIgene • SPUTUM reagent in maintaining viable specimens of Mycobacterium tuberculosis complex (MTBC) during transportation of sputum samples without refrigeration, in comparison to the standard protocol of the National TB Control Program. Sputum samples obtained in southeastern Brazil (June 2017 to July 2018) from 100 sequential patients with positive acid-fast bacillus smear microscopy were divided into two portions. Portion 1 continued to be cooled (standard protocol, STA), but portion 2 was added to OMNIgene • SPUTUM reagent (alternative protocol, OMS) until concomitant further processing. Both portions of all samples were cultured using MGIT and tested by Xpert MTB/RIF assay. Growth of MTBC in the first 42 days was detected in 96% of the cultures under the STA and 88% under the OMS. Intervals between processing and detecting MTBC growth in the two portions significantly differed (p = 0.0001). Portions under the two protocols showed similar results in the MTBC detection by Xpert assay and culture contamination by non-MTBC. The OMNIgene reagent liquefies and decontaminates sputum leading to a decrease in processing time. Although there was a small delay in mycobacterial growth, the OMNIgene reagent can be useful in specimens transported from collection sites over a long distance to centralized testing centers, maintaining viable MTBC for at least 8 days at room temperature.

An infantile late-onset case Group of B Streptococcus meningitis diagnosed with a rapid latex kit.

Globally, vaccination has reduced the prevalence of meningitis caused by Streptococcus pneumoniae Neisseria meningitidis, and Haemophilus influenzae. However, neonatal Group B Streptococcus (GBS) meningitis continues to remain a problematic infection of the central nervous system. Here, we report a case of bacterial meningitis in a 34-day old male baby who presented with fever. A cerebrospinal fluid (CSF) test on the day of admission showed an increase in cell count with decreased glucose level. A rapid latex test of the CSF using a commercial kit diagnosed the causative pathogen as GBS. We administered the antibiotics ampicillin, cefotaxime, gentamicin and panipenem/betamipron to the patient for over 14 days. Partial seizures were frequently observed during the course and were well-controlled with midazolam and phenobarbital. Brain magnetic resonance imaging on day 17 showed subdural hygroma in the frontal region, and 99mTc ethyl-cysteinate dimer-single photon emission computed tomography confirmed a decreased cerebral blood flow predominantly in the left frontal region. After three years of follow-up, the condition of the patient improved without any neurological sequelae. Our report highlights that rapid identification of the causative organism is essential in infantile late-onset meningitis. In addition, we consider that the latex kit-based rapid testing of CSF is beneficial for identifying the causative agent of bacterial meningitis.