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1.
Arch Microbiol ; 206(6): 246, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38704767

RESUMEN

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.


Asunto(s)
Medios de Cultivo , Escherichia coli , Escherichia coli/crecimiento & desarrollo , Volatilización , Medios de Cultivo/química , Reactores Biológicos/microbiología , Técnicas Bacteriológicas/métodos
2.
J Clin Microbiol ; 62(5): e0144523, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38557148

RESUMEN

The virulence of methicillin-resistant Staphylococcus aureus (MRSA) and its potentially fatal outcome necessitate rapid and accurate detection of patients colonized with MRSA in healthcare settings. Using the BD Kiestra Total Lab Automation (TLA) System in conjunction with the MRSA Application (MRSA App), an imaging application that uses artificial intelligence to interpret colorimetric information (mauve-colored colonies) indicative of MRSA pathogen presence on CHROMagar chromogenic media, anterior nares specimens from three sites were evaluated for the presence of mauve-colored colonies. Results obtained with the MRSA App were compared to manual reading of agar plate images by proficient laboratory technologists. Of 1,593 specimens evaluated, 1,545 (96.98%) were concordant between MRSA App and laboratory technologist reading for the detection of MRSA growth [sensitivity 98.15% (95% CI, 96.03, 99.32) and specificity 96.69% (95% CI, 95.55, 97.60)]. This multi-site study is the first evaluation of the MRSA App in conjunction with the BD Kiestra TLA System. Using the MRSA App, our results showed 98.15% sensitivity and 96.69% specificity for the detection of MRSA from anterior nares specimens. The MRSA App, used in conjunction with laboratory automation, provides an opportunity to improve laboratory efficiency by reducing laboratory technologists' labor associated with the review and interpretation of cultures.


Asunto(s)
Automatización de Laboratorios , Técnicas Bacteriológicas , Staphylococcus aureus Resistente a Meticilina , Sensibilidad y Especificidad , Infecciones Estafilocócicas , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Humanos , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Automatización de Laboratorios/métodos , Técnicas Bacteriológicas/métodos , Automatización/métodos , Colorimetría/métodos , Inteligencia Artificial
3.
J Clin Microbiol ; 62(5): e0165123, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38572970

RESUMEN

In clinical bacteriology laboratories, reading and processing of sterile plates remain a significant part of the routine workload (30%-40% of the plates). Here, an algorithm was developed for bacterial growth detection starting with any type of specimens and using the most common media in bacteriology. The growth prediction performance of the algorithm for automatic processing of sterile plates was evaluated not only at 18-24 h and 48 h but also at earlier timepoints toward the development of an early growth monitoring system. A total of 3,844 plates inoculated with representative clinical specimens were used. The plates were imaged 15 times, and two different microbiologists read the images randomly and independently, creating 99,944 human ground truths. The algorithm was able, at 48 h, to discriminate growth from no growth with a sensitivity of 99.80% (five false-negative [FN] plates out of 3,844) and a specificity of 91.97%. At 24 h, sensitivity and specificity reached 99.08% and 93.37%, respectively. Interestingly, during human truth reading, growth was reported as early as 4 h, while at 6 h, half of the positive plates were already showing some growth. In this context, automated early growth monitoring in case of normally sterile samples is envisioned to provide added value to the microbiologists, enabling them to prioritize reading and to communicate early detection of bacterial growth to the clinicians.


Asunto(s)
Inteligencia Artificial , Bacterias , Sensibilidad y Especificidad , Humanos , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Bacterias/clasificación , Algoritmos , Técnicas Bacteriológicas/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Bacteriología , Automatización de Laboratorios/métodos , Medios de Cultivo/química
4.
Diagn Microbiol Infect Dis ; 109(2): 116275, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38537505

RESUMEN

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.


Asunto(s)
Adenosina Trifosfato , Mediciones Luminiscentes , Mycobacterium tuberculosis , Tuberculosis , Mycobacterium tuberculosis/efectos de los fármacos , Adenosina Trifosfato/análisis , Adenosina Trifosfato/metabolismo , Mediciones Luminiscentes/métodos , Humanos , Tuberculosis/diagnóstico , Tuberculosis/microbiología , Sensibilidad y Especificidad , Pruebas de Sensibilidad Microbiana/métodos , Técnicas Bacteriológicas/métodos
5.
PLoS One ; 19(3): e0300042, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38536821

RESUMEN

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.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Gambia , Hidróxido de Sodio , Técnicas Bacteriológicas/métodos , Esputo/microbiología , Tuberculosis/diagnóstico , Tuberculosis/microbiología , Medios de Cultivo
6.
Res Vet Sci ; 172: 105237, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38555775

RESUMEN

This study includes the evaluation of multiplex real-time PCR (rPCR) kit, which was developed to provide rapid diagnosis of mastitis infections, by working with milk samples of 2 different sources of mastitis and comparing the results with the classical bacteriological culture method (BC). A total of 273 bacteria were isolated in 226 samples (47.88%) out of 472 samples by BC. These were 139 (50.91%) Staphylococcus spp., 61 (22.34%) Streptococcus spp., 15 (5.49%) E. coli, 8 (2.93%) Enterococcus spp., 50 (18.31%) other bacteria. When we look at the multiplex rPCR results; 1052 positive were obtained for the gene regions of 14 different bacteria, 1 yeast, and 1 ß-lactamase gene examined in 472 samples. While no searched gene region was found by rPCR in 78 (16.5%) of the 472 samples studied, at least 1 gene was detected in 394 (83.5%) samples. These 1052 positive samples by rPCR were; 263 (28.43%) Staphylococcus spp., 51 (5.51%) S. aureus, 57 (6.16%) Enterococcus spp., 49 (5.29%) C. bovis, 16 (1.73%) S. dysgalactiae, 84 (9.08%) S. agalactiae, 71 (7.67%) S. uberis, 73 (7.89%) E. coli, 14 (1.51%) Prototheca spp., 39 (4.21%) T. pyogenes/P. indolicus, 5 (0.54%) S. marcescens, 15 (1.62%) K. oxytoca/pneumonia, 117 (12.64%) Mycoplasma spp., 31 (3.35%) M. bovis, 40 (4.32%) yeast, and 127 samples (26.90%) were ß-lactamase positive. When the antibiotic resistance of the isolates was evaluated, 78 (31.96%) tetracycline, 72 (29.5%) penicillin, and 60 (24.59%) clindamycin resistance were observed predominantly in Gram-positive isolates, while 6 (23.07%) tigecycline, 6 (23.07%) netilmicin, 6 (23.07%) pipercillin resistance was found in gram-negative isolates. While a bacteria and/or yeast gene was found by rPCR in 187 of 246 (76.01%) samples with no bacterial growth, a bacterium was isolated with BC in only 20 (8.84%) samples whose gene region was not found by rPCR. As a result, the multiplex rPCR system used in the diagnosis of mastitis has been found to be quite reliable as it can detect a large number of bacteria in a very short time compared to classical methods. Therefore, we advise the use of rPCR and/or culture for confirmation of clinical signs in mastitis and at routine mastitis surveillance.


Asunto(s)
Mastitis Bovina , Reacción en Cadena de la Polimerasa Multiplex , Reacción en Cadena en Tiempo Real de la Polimerasa , Mastitis Bovina/microbiología , Mastitis Bovina/diagnóstico , Femenino , Animales , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Bovinos , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Reacción en Cadena de la Polimerasa Multiplex/métodos , Técnicas Bacteriológicas/métodos , Técnicas Bacteriológicas/veterinaria , Leche/microbiología , Bacterias/aislamiento & purificación , Bacterias/genética , Bacterias/clasificación
7.
Lett Appl Microbiol ; 77(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38364315

RESUMEN

The objective of this study is to validate the US Food and Drug Administration (FDA) rea-time polymerase chain reaction (qPCR) assay, the Neogen Amplified Nucleic Single Temperature Reaction (ANSR) assay, and the Vitek ImmunoDiagnostic Assay System (VIDAS) SLM procedure against the FDA cultural procedure for Salmonella detection in green chile pepper. Green chile was artificially contaminated with Salmonella according to the FDA guidelines (FDA. Guidelines for the Validation of Microbiological Methods for the FDA Foods Program, 3rd Edition. 2019. www.fda.gov/media/83812/download?attachment (17 March 2024, date last accessed)) at a fractional recovery level (where 50%-25% tests positive and at a level +1 log greater for each organism tested). Enriched samples were tested directly by the ANSR Salmonella test and by qPCR, and were subcultured into Rappaport-Vassiliadis and tetrathionate brilliant green broth for cultural detection and qPCR. For the VIDAS-SLM assay, the selective enrichments were further cultured in M broth before testing. Presumptive salmonellae were confirmed with biochemical tests, serology, and qPCR. All three rapid assays were compared favorably with the FDA-BAM (Bacteriological Analytical Manual) method. No significant differences at P < .05 were found between the procedures using McNemar's χ2 test. The three procedures were found to be rapid and reliable alternatives to cultural detection of Salmonella enterica in green chile.


Asunto(s)
Microbiología de Alimentos , Salmonella enterica , Medios de Cultivo , Salmonella enterica/genética , Chile , Técnicas Bacteriológicas/métodos , Salmonella
8.
J Clin Microbiol ; 62(1): e0109623, 2024 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-38054730

RESUMEN

Rapid diagnostic tests (RDTs) for bloodstream infections have the potential to reduce time to appropriate antimicrobial therapy and improve patient outcomes. Previously, an in-house, lipid-based, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) method, Fast Lipid Analysis Technique (FLAT MS), has shown promise as a rapid pathogen identification method. In this study, FLAT MS for direct from blood culture identification was evaluated and compared to FDA-cleared identification methods using the Benefit-risk Evaluation Framework (BED-FRAME) analysis. FLAT MS was evaluated and compared to Bruker Sepsityper and bioMérieux BioFire FilmArray BCID2 using results from a previous study. For this study, 301 positive blood cultures were collected from the University of Maryland Medical Center. The RDTs were compared by their sensitivities, time-to-results, hands-on time, and BED-FRAME analysis. The overall sensitivity of all platforms compared to culture results from monomicrobial-positive blood cultures was 88.3%. However, the three RDTs differed in their accuracy for identifying Gram-positive bacteria, Gram-negative bacteria, and yeast. Time-to-results for FLAT MS, Sepsityper, and BioFire BCID2 were all approximately one hour. Hands-on times for FLAT MS, Sepsityper, and BioFire BCID2 were 10 (±1.3), 40 (±2.8), and 5 (±0.25) minutes, respectively. BED-FRAME demonstrated that each RDT had utility at different pathogen prevalence and relative importance. BED-FRAME is a useful tool that can used to determine which RDT is best for a healthcare center.


Asunto(s)
Bacteriemia , Sepsis , Humanos , Bacteriemia/diagnóstico , Bacteriemia/microbiología , Prueba de Diagnóstico Rápido , Técnicas Bacteriológicas/métodos , Sepsis/diagnóstico , Cultivo de Sangre , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Lípidos
9.
J Vet Diagn Invest ; 36(1): 124-127, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37919965

RESUMEN

Carbapenemase-producing Enterobacterales (CPE) are one of the most urgent threats to human healthcare globally. Descriptions of CPE outbreaks in veterinary hospitals suggest the need for screening strategies for CPE from companion animals. Our aim was to optimize a chromogenic agar method with and without selective enrichment to isolate CPE from companion animal feces in an ongoing outbreak of New Delhi metallo-ß-lactamse-5 Escherichia coli. A limit of detection (LOD) assay for spiked canine and feline feces was performed for both methods using a carbapenamase-producing E. coli (24213-18); the LOD (1.5 × 103 cfu/g of feces) was equivalent to that reported for human fecal specimens. We screened 1,247 companion animal fecal specimens for carriage of CPE by 1) direct plating to chromogenic agar and 2) plating to chromogenic agar following selective enrichment. Twenty-one specimens were positive for CPE by both direct culture and enrichment culture. No specimens were positive with selective enrichment and negative by direct culture. A selective enrichment step did not result in any increased recovery of CPE from companion animals, which suggests that enrichment broth may not be necessary for outbreak surveillance testing. It is important to continue to validate methods for the detection of CPE in companion animals as outbreaks become more common in veterinary facilities.


Asunto(s)
Enfermedades de los Gatos , Enfermedades de los Perros , Infecciones por Enterobacteriaceae , Animales , Gatos , Perros , Humanos , Escherichia coli , Enterobacteriaceae , Agar , Enfermedades de los Gatos/diagnóstico , Enfermedades de los Gatos/epidemiología , Técnicas Bacteriológicas/veterinaria , Técnicas Bacteriológicas/métodos , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/epidemiología , Proteínas Bacterianas , Brotes de Enfermedades/veterinaria , Infecciones por Enterobacteriaceae/diagnóstico , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/veterinaria , Pruebas de Sensibilidad Microbiana/veterinaria
10.
J Clin Microbiol ; 62(1): e0115223, 2024 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-38126761

RESUMEN

The objective of this study was to assess the clinical performances of PhenoMATRIX and PhenoMATRIX PLUS for the screening of methicillin-resistant Staphylococcus aureus (MRSA) from nasal and inguinal/perineal ESwabs using chromogenic media. The automated performances were compared to the manual reading. Additionally, we evaluated PhenoMATRIX PLUS for the automatic release of the negative results to the Laboratory Information System (LIS) and the automatic discharge of the negative plates from the incubators. A total of 6,771 non-duplicate specimens were used by PhenoMATRIX as a machine learning model. The validation of these settings was performed on 17,223 non-duplicate specimens. The MRSA positivity rate was 5% (866/17,223). Validated settings were then used by PhenoMATRIX PLUS on another 1,409 non-duplicate specimens. The sensitivities of PhenoMATRIX and PhenoMATRIX PLUS were 99.8% [95% confidence interval (CI), 99.2%-99.9%] and 100% (95% CI, 92.1%-100%), respectively. The specificities of PhenoMATRIX and PhenoMATRIX PLUS were 99.1% (95% CI, 99.0%-99.2%) and 95.2% (95% CI, 93.8%-96.1%), respectively. All the 1,297 MRSA-negative specimens analyzed by PhenoMATRIX PLUS were automatically released and sent to the LIS immediately after availability of the culture image on the WASPLab (100% accuracy). All negative media plates were automatically discarded. PhenoMATRIX PLUS decreases the time spent by technologists on negative plates and ensures optimal usage of the incubators' capacity.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Humanos , Técnicas Bacteriológicas/métodos , Sensibilidad y Especificidad , Compuestos Cromogénicos , Nariz , Infecciones Estafilocócicas/diagnóstico , Medios de Cultivo
11.
Food Res Int ; 174(Pt 2): 113665, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37981373

RESUMEN

As outbreaks of foodborne illness caused by the opportunistic pathogen Cronobacter sakazakii (Cs) continue to occur, particularly in infants consuming powdered infant formula (PIF), the need for sensitive, rapid, and easy-to-use detection of Cs from food and food processing environments is increasing. Here, we developed bioluminescent reporter bacteriophages for viable Cs-specific, substrate-free, rapid detection by introducing luciferase and its corresponding substrate-providing enzyme complex into the virulent phage ΦC01. Although the reporter phage ΦC01_lux, constructed by replacing non-essential genes for phage infectivity with a luxCDABE reporter operon, produced bioluminescence upon Cs infection, the emitted signal was quickly decayed due to the superior bacteriolytic activity of ΦC01. By truncating the membrane pore-forming protein holin and thus limiting its function, the bacterial lysis was delayed and the resultant engineered reporter phage ΦC01_lux_Δhol could produce a more stable and reliable bioluminescent signal. Accordingly, ΦC01_lux_Δhol was able to detect at least an average of 2 CFU/ml of Cs artificially contaminated PIF and Sunsik and food contact surface models within a total of 7 h of assays, including 5 h of pre-enrichment for Cs amplification. The sensitive, easy-to-use, and specific detection of live Cs with the developed reporter phage could be applied as a novel complementary tool for monitoring Cs in food and food-related environments for food safety and public health.


Asunto(s)
Técnicas Bacteriológicas , Bacteriófagos , Cronobacter sakazakii , Microbiología de Alimentos , Mediciones Luminiscentes , Proteínas Virales , Cronobacter sakazakii/genética , Cronobacter sakazakii/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Bacteriófagos/genética , Bacteriófagos/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo , Microbiología de Alimentos/métodos , Genoma Viral/genética , Eliminación de Secuencia , Mediciones Luminiscentes/métodos , Sensibilidad y Especificidad
12.
Rev Esp Quimioter ; 36(6): 621-624, 2023 Dec.
Artículo en Español | MEDLINE | ID: mdl-37786957

RESUMEN

OBJECTIVE: The prevalence of carbapenemase-producing Enterobacterales has increased in recent years and is considered an important public health problem. METHODS: A total of 106 clinical samples were analyzed by different carbapenemase detection techniques: inhibition discs (ID), immunochromatographic test (ICT) and a genotypic method, comparing them with a multiplex RT-PCR as a reference method. RESULTS: Overall, all 3 techniques exceeded 90% sensitivity, although with differences in the performance of some of them by carbapenemase type. DI had low specificity (62%) for OXA-48, while with TIC the sensitivity for NDM-type metallo-beta-lactamase (93%) was slightly lower than for OXA-48 (95%). The best results were obtained with the genotypic technique (100% overall performance). CONCLUSIONS: Despite the lower sensitivity of TICs (especially in NDM carbapenemases) compared to molecular techniques, with the modification of the protocol we managed to increase this sensitivity and, together with the lower price, simplicity and speed, it makes this technique a good screening option.


Asunto(s)
Técnicas Bacteriológicas , beta-Lactamasas , Humanos , Técnicas Bacteriológicas/métodos , beta-Lactamasas/genética , beta-Lactamasas/análisis , Proteínas Bacterianas/genética , Proteínas Bacterianas/análisis , Enterobacteriaceae/genética , Sensibilidad y Especificidad , Pruebas de Sensibilidad Microbiana
13.
Diagn Microbiol Infect Dis ; 107(4): 116085, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37801888

RESUMEN

BACKGROUND: We evaluated pre- and postimplementation of Virtuo on outcome in patients with gram-negative bacteremia using a quasiexperimental time-in-motion design. METHODS: Becton Dickinson BACTEC™ 9000 series (Bactec) (2018) and Virtuo system (2020) were utilized in a decentralized and centralized process, respectively. Data collected in August-December in 2018 and 2020 were analyzed with SPSS (ver 28). RESULTS: For 185 patients in each time period, patient age, gender, length of hospitalization were not different. However, blood culture (BC) volume was significantly lower in 2020 (7.1 ± 2.6 mL) compared to 2018 (8.9 ± 1.9 mL). Time from BC draw and time from pathogen identification (ID) to treatment change were both significantly faster in 2020 (52.9 ± 38.3 hours; 15.1 ± 27.4 hours), compared to 2018 (65.0 ± 46.3 hours; 23.8 ± 33.8), respectively. CONCLUSIONS: Replacement of decentralized Bactec with centralized Virtuo, resulted in significant improvement in management of patients gram-negative bacteremia.


Asunto(s)
Bacteriemia , Cultivo de Sangre , Humanos , Cultivo de Sangre/métodos , Factores de Tiempo , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Medios de Cultivo , Técnicas Bacteriológicas/métodos
14.
J Biol Chem ; 299(11): 105286, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37742925

RESUMEN

The twin arginine translocation (Tat) pathway transports folded protein across the cytoplasmic membrane in bacteria, archaea, and across the thylakoid membrane in plants as well as the inner membrane in some mitochondria. In plant chloroplasts, the Tat pathway utilizes the protonmotive force (PMF) to drive protein translocation. However, in bacteria, it has been shown that Tat transport depends only on the transmembrane electrical potential (Δψ) component of PMF in vitro. To investigate the comprehensive PMF requirement in Escherichia coli, we have developed the first real-time assay to monitor Tat transport utilizing the NanoLuc Binary Technology in E. coli spheroplasts. This luminescence assay allows for continuous monitoring of Tat transport with high-resolution, making it possible to observe subtle changes in transport in response to different treatments. By applying the NanoLuc assay, we report that, under acidic conditions (pH = 6.3), ΔpH, in addition to Δψ, contributes energetically to Tat transport in vivo in E. coli spheroplasts. These results provide novel insight into the mechanism of energy utilization by the Tat pathway.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Sistema de Translocación de Arginina Gemela , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Señales de Clasificación de Proteína/fisiología , Transporte de Proteínas/fisiología , Fuerza Protón-Motriz , Mediciones Luminiscentes , Técnicas Bacteriológicas/instrumentación , Técnicas Bacteriológicas/métodos , Metabolismo Energético , Esferoplastos/efectos de los fármacos , Esferoplastos/metabolismo , Ionóforos/farmacología
15.
Diagn Microbiol Infect Dis ; 107(3): 116043, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37657230

RESUMEN

The Resist Acineto from Coris Bioconcept is a novel immunochromatographic test for detection of the major acquired carbapenemases (OXA-23, OXA-40, OXA-58, and NDM) identified in Acinetobacter spp. This rapid and easy-to-perform test showed an excellent specificity and sensitivity, with positive and negatives predictive values of 100% in both cases.


Asunto(s)
Acinetobacter , Enterobacteriaceae , Humanos , Técnicas Bacteriológicas/métodos , Sensibilidad y Especificidad , beta-Lactamasas/análisis , Proteínas Bacterianas/análisis , Pruebas Inmunológicas , Pruebas de Sensibilidad Microbiana
16.
World J Microbiol Biotechnol ; 39(10): 282, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37589866

RESUMEN

Bloodstream infections are a growing public health concern due to emerging pathogens and increasing antimicrobial resistance. Rapid antibiotic susceptibility testing (AST) is urgently needed for timely and optimized choice of antibiotics, but current methods require days to obtain results. Here, we present a general AST protocol based on surface-enhanced Raman scattering (SERS-AST) for bacteremia caused by eight clinically relevant Gram-positive and Gram-negative pathogens treated with seven commonly administered antibiotics. Our results show that the SERS-AST protocol achieves a high level of agreement (96% for Gram-positive and 97% for Gram-negative bacteria) with the widely deployed VITEK 2 diagnostic system. The protocol requires only five hours to complete per blood-culture sample, making it a rapid and effective alternative to conventional methods. Our findings provide a solid foundation for the SERS-AST protocol as a promising approach to optimize the choice of antibiotics for specific bacteremia patients. This novel protocol has the potential to improve patient outcomes and reduce the spread of antibiotic resistance.


Asunto(s)
Bacteriemia , Técnicas Bacteriológicas , Farmacorresistencia Bacteriana , Espectrometría Raman , Bacteriemia/microbiología , Antibacterianos/farmacología , Bacterias/clasificación , Bacterias/efectos de los fármacos , Humanos , Técnicas Bacteriológicas/métodos , Cultivo de Sangre
17.
Diagn Microbiol Infect Dis ; 107(2): 116020, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37536259

RESUMEN

A newly developed Clostridioides difficile-selective growth broth, which can be cultured under aerobic conditions, was found to have a sensitivity/specificity (98%/89%) comparable to conventional anaerobic culture methods. This might be a powerful tool for diagnosing Clostridioides difficile infection in resource-limited regions and health care settings in the future.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Humanos , Clostridioides , Técnicas Bacteriológicas/métodos , Infecciones por Clostridium/diagnóstico , Sensibilidad y Especificidad
19.
BMC Infect Dis ; 23(1): 494, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37495964

RESUMEN

BACKGROUND: Smear microscopy has remained the initial diagnostic test for presumptive tuberculosis (TB) patients in health facilities without the World Health Organization (WHO) recommended rapid diagnostic tools. In the Uganda TB laboratory network, the technique remains the only tool to monitor response to treatment among drug susceptible TB patients, with the country currently having over 1,600 microscopy TB testing units. It has been evidenced that acid-fast bacilli (AFB) microscopy's yield highly depends on the staining technique and reading ability of the laboratory personnel. For the quality of TB testing in the country, the TB control program set up a Randomized Blinded Rechecking (RBRC) program in 2008 to monitor the testing performance of laboratories to continuously improve the reliability and efficiency of results. This is the first study to determine the effectiveness and impact of the RBRC program on the performance of the participating laboratories in Uganda. METHODS: This was a retrospective cross-sectional study based on a record review of the RBRC's annual results compilations between January 2008 and December 2017. RESULTS: Between January 2008 and December 2017, a total of 265,523 smears were re-checked during the RBRC program. The number of enrolled laboratories in the RBRC program rose from 660 to 2008 to 1,406 in 2017. The RBRC program resulted in a statistically significant reduction in microscopy errors, with false positives decreasing from 12.8% to 2008 to 7.6% in 2017, false positive errors decreasing from 10 to 6.3%, false negative errors decreasing from 2.9 to 0.7%, quantification errors decreasing from 6.0 to 1.8%, and the overall sensitivity of smear microscopy compared to the controllers increased with statistical significance from 93 to 97%. CONCLUSION: The study reveals an overall significant error reduction and an improved sensitivity of smear microscopy upon continuous implementation of the RBRC program in an AFB microscopy TB laboratory network. Implementation of a RBRC program is crucial and essential to maintaining a reliable TB laboratory service that can facilitate accurate diagnosis and offset the disadvantages of using smear microscopy.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Estudios Retrospectivos , Laboratorios , Microscopía/métodos , Estudios Transversales , Reproducibilidad de los Resultados , Uganda , Control de Calidad , Esputo , Técnicas Bacteriológicas/métodos , Tuberculosis/diagnóstico
20.
J Clin Microbiol ; 61(8): e0021223, 2023 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-37493547

RESUMEN

During the past decade, MALDI-TOF mass spectrometry (MS) has become a standard method for identification of bacteria and yeasts. Nonetheless, further optimization of the identification process is important to streamline workflows and save resources. This study evaluated the application of a multipurpose benchtop tool, MBT FAST Shuttle IVD, for accelerated drying of liquid assay components (matrix, formic acid, and/or sample) on a MALDI target. A total of 50 bacterial and fungal isolates were subjected to three different sample preparation procedures prior to the identification by MALDI-TOF MS: direct transfer (DT), extended direct transfer (eDT), and protein extraction (PE). Compared to conventional drying at room temperature, the preparation was performed with standardized heating of the MALDI target on the MBT FAST Shuttle. During DT, eDT, and PE, 56.7% (P < 0.001), 56.8% (P < 0.001), and 52.8% (P < 0.001) of time for matrix drying were saved by using the MBT FAST Shuttle, respectively. Applying the MBT FAST Shuttle, 57.5% (P < 0.001) of time for drying of formic acid were saved for eDT and 57.5% (P < 0.001) of time for sample drying were saved for PE. A significant improvement of the identification rates and scores was observed with MBT FAST Shuttle for eDT (P = 0.001) and PE (P = 0.008) methods, while the effect on identification quality for DT was not statistically significant (P = 0.16). In conclusion, the use of the MBT FAST Shuttle shortened the drying time of assay components by about a half for all preparation methods. Moreover, positive effect on identification success was observed.


Asunto(s)
Técnicas Bacteriológicas , Formiatos , Humanos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Técnicas Bacteriológicas/métodos , Bacterias , Aceleración
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