Comparison of two MALDI-TOF MS systems for theidentification of clinically relevant anaerobic bacteriain Argentina

Abstract The aim of this study was to compare the performance of two MALDI-TOF MS systems in the identification of clinically relevant strict anaerobic bacteria. The 16S rRNA gene sequencing was the gold standard method when discrepancies or inconsistencies were observed between platforms. A total of 333 isolates were recovered from clinical samples of different centers in Buenos Aires City between 2016 and 2021. The isolates were identified in duplicate using two MALDI-TOF MS systems, BD Bruker Biotyper (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMèrieux, Marcy-l'Etoile, France). Using the Vitek MS system, the identification of anaerobic isolates yielded the following percentages: 65.5% (n: 218) at the species or species-complex level, 71.2% (n: 237) at the genus level, 29.4% (n: 98) with no identification and 5.1% (n: 17) with misidentification. Using the Bruker Biotyper system, the identification rates were as follows: 85.3% (n: 284) at the species or species-complex level, 89.7% (n: 299) at the genus level, 14.1% (n: 47) with no identification and 0.6% (n: 2) with misidentification. Differences in the performance of both methods were statistically significant (p-values <0.0001). In conclusion, MALDI-TOF MS systems speed up microbial identification and are particularly effective for slow-growing microorganisms, such as anaerobic bacteria, which are difficult to identify by traditional methods. In this study, the Bruker system showed greater accuracy than the Vitek system. In order to be truly effective, it is essential to update the databases of both systems by increasing the number of each main spectrum profile within the platforms.

Resumen El objetivo de este estudio fue comparar el desempeño de dos sistemas MALDI-TOF MS en la identificación de bacterias anaerobias estrictas de interés clínico. La secuenciación del gen 16S ARNr fue el método de referencia utilizado cuando se observaron discrepancias o inconsistencias entre plataformas. Se recuperaron 333 aislados de muestras clínicas de diferentes centros de la Ciudad Autónoma de Buenos Aires entre 2016 y 2021. Los aislados se identificaron por duplicado mediante dos sistemas MALDI-TOF MS: el BD Bruker Biotyper (Bruker Daltonics, Bremen, Alemania) y el Vitek MS (bioMèrieux, Marcy-l'Etoile, Francia). A través del sistema Vitek MS, los mismos fueron identificados a nivel de especie o complejo de especies en un 65,5% (n: 218) y de género en un 71,2% (n: 237), mientras que no se identificaron en un 29,4% (n: 98) y fue incorrecta en el 5,1% (n: 17). Mediante el sistema Bruker Biotyper, dichos valores fueron del 85,3% (n: 284), del 89,7% (n: 299), del 14,1% (n: 47) y del 0,6% (n: 2), respectivamente. La diferencia entre ambos métodos fue estadísticamente significativa (p<0,0001). En conclusión, los sistemas MALDI-TOF MS aceleran la identificación microbiana. Son especialmente útiles para los microorganismos de crecimiento lento, como las bacterias anaerobias, que son difíciles de identificar con los métodos tradicionales. El sistema Bruker demostró ser más preciso que el Vitek MS. Para que estos métodos sean realmente efectivos es fundamental actualizar las bases de datos de ambos sistemas e incrementar el número de espectros de referencia dentro de las plataformas.

Comparison of two MALDI-TOF MS systems for the identification of clinically relevant anaerobic bacteria in Argentina.

The aim of this study was to compare the performance of two MALDI-TOF MS systems in the identification of clinically relevant strict anaerobic bacteria. The 16S rRNA gene sequencing was the gold standard method when discrepancies or inconsistencies were observed between platforms. A total of 333 isolates were recovered from clinical samples of different centers in Buenos Aires City between 2016 and 2021. The isolates were identified in duplicate using two MALDI-TOF MS systems, BD Bruker Biotyper (Bruker Daltonics, Bremen, Germany) and Vitek MS (bioMèrieux, Marcy-l'Etoile, France). Using the Vitek MS system, the identification of anaerobic isolates yielded the following percentages: 65.5% (n: 218) at the species or species-complex level, 71.2% (n: 237) at the genus level, 29.4% (n: 98) with no identification and 5.1% (n: 17) with misidentification. Using the Bruker Biotyper system, the identification rates were as follows: 85.3% (n: 284) at the species or species-complex level, 89.7% (n: 299) at the genus level, 14.1% (n: 47) with no identification and 0.6% (n: 2) with misidentification. Differences in the performance of both methods were statistically significant (p-values <0.0001). In conclusion, MALDI-TOF MS systems speed up microbial identification and are particularly effective for slow-growing microorganisms, such as anaerobic bacteria, which are difficult to identify by traditional methods. In this study, the Bruker system showed greater accuracy than the Vitek system. In order to be truly effective, it is essential to update the databases of both systems by increasing the number of each main spectrum profile within the platforms.

Diagnóstico microbiológico de infección por Clostridioides difficile en épocas de COVID-19 en un hospital pediátrico de alta complejidad / Microbiological diagnosis of Clostridioides difficile infection in times of COVID-19 in a high complexity pediatric hospital

Resumen La infección por Clostridioides difficile (ICD) puede variar desde diarrea hasta megacolon tóxico. Los objetivos del trabajo fueron mostrar la variación en el número de casos diagnosticados de ICD en este laboratorio entre 2020, cuando comenzó la pandemia de COVID-19 y 2019 y 2021 y detallar los casos precedidos por la infección de SARS-CoV-2. El presente es un estudio retrospectivo observacional en el que se registraron el número total de muestras procesadas con sospecha de ICD y el de positivas y los antecedentes clínicos de pacientes con ICD hasta dos meses después de su diagnóstico de COVID-19. Durante 2020 se procesaron menos muestras que en 2019 y 2021; sin embargo, el porcentaje de positividad fue de 13,1%, 7,2% y 7,8%, respectivamente. Esto pudo deberse a mejoras en el criterio clínico al momento de seleccionar las muestras con sospecha de ICD.

Abstract Clostridioides difficile infection (CDI) can cause anything from diarrhea to toxic megacolon. The objectives of this study were: to show the variation in the number of diagnosed cases of CDI in this center, comparing 2020, when the COVID-19 pandemic began, with 2019 and 2021 and to detail cases preceded by SARS-CoV-2 infection. This is an observational retrospective study in which the total number of samples processed with suspected CDI were recorded. The positive ones and the clinical history of patients with a diagnosis of CDI up to two months after their diagnosis of SARS-CoV-2 infection were recorded as well. During 2020 a smaller number of samples were processed. However, during this year the percentage of positivity was 13.1% vs. 7,2% and 7.8% during 2019 and 2021, respectively. It is believed that this may have been due to improvements in clinical suspicion and sample selection for CDI diagnosis.

Resumo A infecção por Clostridioides difficile (ICD) pode causar desde diarreia até megacólon tóxico. Os objetivos desta apresentação foram: mostrar a variação do número de casos diagnosticados de ICD neste laboratório, entre 2020 quando começou a pandemia de COVID-19 e 2019 e 2021 e, detalhar os casos precedidos pela infecção por SARS-CoV-2. Esse estudo foi retrospectivo observacional e foram registrados: o número total de amostras processadas com suspeita de ICD e de amostras positivas e os antecedentes clínicos daqueles pacientes com diagnóstico de ICD até dois meses após o diagnóstico de COVID 19. Durante 2020, foram processadas menos amostras do que em 2019 e 2021; no entanto, o percentual de positividade foi de 13,1%, 7,2% e 7,8%, respectivamente. Isso pode ter sido resultado de melhorias no critério clínico na hora de selecionar as amostras com suspeita de ICD.

Clinical Presentation, Treatment Outcomes, and Resistance-related Factors in South American Women with Low-risk Postmolar Gestational Trophoblastic Neoplasia / Apresentação clínica, resultados do tratamento e fatores relacionados à resistência em mulheres sul-americanas com neoplasia trofoblástica gestacional pós-molar de baixo risco

Abstract Objective There are few multinational studies on gestational trophoblastic neoplasia (GTN) treatment outcomes in South America. The purpose of this study was to assess the clinical presentation, treatment outcomes, and factors associated with chemoresistance in low-risk postmolar GTN treated with first-line single-agent chemotherapy in three South American centers. Methods Multicentric, historical cohort study including women with International Federation of Gynecology and Obstetrics (FIGO)-staged low-risk postmolar GTN attending centers in Argentina, Brazil, and Colombia between 1990 and 2014. Data were obtained on patient characteristics, disease presentation, and treatment response. Logistic regression was used to assess the relationship between clinical factors and resistance to first-line single-agent treatment. A multivariate analysis of the clinical factors significant in univariate analysis was performed. Results A total of 163 women with low-risk GTN were included in the analysis. The overall rate of complete response to first-line chemotherapy was 80% (130/163). The rates of complete response to methotrexate or actinomycin-D as first-line treatment, and actinomycin-D as second-line treatment postmethotrexate failure were 79% (125/157), 83% (⅚), and 70% (23/33), respectively. Switching to second-line treatment due to chemoresistance occurred in 20.2% of cases (33/163). The multivariate analysis demonstrated that patients with a 5 to 6 FIGO risk score were 4.2-fold more likely to develop resistance to first-line single-agent treatment (p= 0.019). Conclusion 1) At presentation, most women showed clinical characteristics favorable to a good outcome, 2) the overall rate of sustained complete remission after first-line single-agent treatment was comparable to that observed in developed countries, 3) a FIGO risk score of 5 or 6 is associated with development of resistance to first-line single-agent chemotherapy.

Resumo Objetivo Existem poucos estudos multinacionais sobre os resultados do tratamento da neoplasia trofoblástica gestacional (NTG) na América do Sul. O objetivo deste estudo foi avaliar a apresentação clínica, os resultados do tratamento e os fatores associados a casos de quimiorresistência em NTG pós-molar de baixo risco tratados com quimioterapia de agente único de primeira linha em três centros sul-americanos. Métodos Estudo multicêntrico de coorte histórica incluindo mulheres com NTG pós-molar de baixo risco com estadiamento International Federation of Gynecology and Obstetrics (FIGO) em centros de atendimento na Argentina, Brasil e Colômbia entre 1990 e 2014. Foram obtidos dados sobre as características do paciente, apresentação da doença e resposta ao tratamento. A regressão logística foi usada para avaliar a relação entre fatores clínicos e resistência ao tratamento de primeira linha com agente único. Foi realizada uma análise multivariada dos fatores clínicos significativos na análise univariada. Resultados Cento e sessenta e três mulheres com NTG de baixo risco foram incluídas na análise. A taxa global de resposta completa à quimioterapia de primeira linha foi de 80% (130/163). As taxas de resposta completa ao metotrexato ou actinomicina-D como tratamento de primeira linha e actinomicina-D como tratamento de segunda linha após falha do metotrexato foram 79% (125/157), 83% (⅚) e 70% (23/33), respectivamente. A mudança para o tratamento de segunda linha por quimiorresistência ocorreu em 20,2% dos casos (33/163). A análise multivariada demonstrou que pacientes com pontuação de risco FIGO de 5 a 6 foram 4,2 vezes mais propensos a desenvolver resistência ao tratamento com agente único de primeira linha (p= 0,019). Conclusão 1) Na apresentação, a maioria das mulheres demonstrou características clínicas favoráveis a um bom resultado, 2) a taxa geral de remissão completa sustentada após o tratamento de primeira linha com agente único foi comparável à de países desenvolvidos, 3) um escore de risco FIGO de 5 ou 6 está associado ao desenvolvimento de resistência à quimioterapia de agente único de primeira linha.

Clinical Presentation, Treatment Outcomes, and Resistance-related Factors in South American Women with Low-risk Postmolar Gestational Trophoblastic Neoplasia.

OBJECTIVE: There are few multinational studies on gestational trophoblastic neoplasia (GTN) treatment outcomes in South America. The purpose of this study was to assess the clinical presentation, treatment outcomes, and factors associated with chemoresistance in low-risk postmolar GTN treated with first-line single-agent chemotherapy in three South American centers. METHODS: Multicentric, historical cohort study including women with International Federation of Gynecology and Obstetrics (FIGO)-staged low-risk postmolar GTN attending centers in Argentina, Brazil, and Colombia between 1990 and 2014. Data were obtained on patient characteristics, disease presentation, and treatment response. Logistic regression was used to assess the relationship between clinical factors and resistance to first-line single-agent treatment. A multivariate analysis of the clinical factors significant in univariate analysis was performed. RESULTS: A total of 163 women with low-risk GTN were included in the analysis. The overall rate of complete response to first-line chemotherapy was 80% (130/163). The rates of complete response to methotrexate or actinomycin-D as first-line treatment, and actinomycin-D as second-line treatment postmethotrexate failure were 79% (125/157), 83% (⅚), and 70% (23/33), respectively. Switching to second-line treatment due to chemoresistance occurred in 20.2% of cases (33/163). The multivariate analysis demonstrated that patients with a 5 to 6 FIGO risk score were 4.2-fold more likely to develop resistance to first-line single-agent treatment (p = 0.019). CONCLUSION: 1) At presentation, most women showed clinical characteristics favorable to a good outcome, 2) the overall rate of sustained complete remission after first-line single-agent treatment was comparable to that observed in developed countries, 3) a FIGO risk score of 5 or 6 is associated with development of resistance to first-line single-agent chemotherapy.

OBJETIVO: Existem poucos estudos multinacionais sobre os resultados do tratamento da neoplasia trofoblástica gestacional (NTG) na América do Sul. O objetivo deste estudo foi avaliar a apresentação clínica, os resultados do tratamento e os fatores associados a casos de quimiorresistência em NTG pós-molar de baixo risco tratados com quimioterapia de agente único de primeira linha em três centros sul-americanos. MéTODOS: Estudo multicêntrico de coorte histórica incluindo mulheres com NTG pós-molar de baixo risco com estadiamento International Federation of Gynecology and Obstetrics (FIGO) em centros de atendimento na Argentina, Brasil e Colômbia entre 1990 e 2014. Foram obtidos dados sobre as características do paciente, apresentação da doença e resposta ao tratamento. A regressão logística foi usada para avaliar a relação entre fatores clínicos e resistência ao tratamento de primeira linha com agente único. Foi realizada uma análise multivariada dos fatores clínicos significativos na análise univariada. RESULTADOS: Cento e sessenta e três mulheres com NTG de baixo risco foram incluídas na análise. A taxa global de resposta completa à quimioterapia de primeira linha foi de 80% (130/163). As taxas de resposta completa ao metotrexato ou actinomicina-D como tratamento de primeira linha e actinomicina-D como tratamento de segunda linha após falha do metotrexato foram 79% (125/157), 83% (⅚) e 70% (23/33), respectivamente. A mudança para o tratamento de segunda linha por quimiorresistência ocorreu em 20,2% dos casos (33/163). A análise multivariada demonstrou que pacientes com pontuação de risco FIGO de 5 a 6 foram 4,2 vezes mais propensos a desenvolver resistência ao tratamento com agente único de primeira linha (p = 0,019). CONCLUSãO: 1) Na apresentação, a maioria das mulheres demonstrou características clínicas favoráveis a um bom resultado, 2) a taxa geral de remissão completa sustentada após o tratamento de primeira linha com agente único foi comparável à de países desenvolvidos, 3) um escore de risco FIGO de 5 ou 6 está associado ao desenvolvimento de resistência à quimioterapia de agente único de primeira linha.

Outcomes in the management of high-risk gestational trophoblastic neoplasia in trophoblastic disease centers in South America.

BACKGROUND: South America has a higher incidence of gestational trophoblastic disease than North America or Europe, but whether this impacts chemotherapy outcomes is unclear. The purpose of this study was to evaluate outcomes among women with high-risk gestational trophoblastic neoplasia (GTN) treated at trophoblastic disease centers in developing South American countries. METHODS: This retrospective cohort study included patients with high-risk GTN treated in three trophoblastic disease centers in South America (Botucatu and Rio de Janeiro, Brazil, and Buenos Aires, Argentina) from January 1990 to December 2014. Data evaluated included demographics, clinical presentation, FIGO stage, WHO prognostic risk score, and treatment-related information. The primary treatment outcome was complete sustained remission by 18 months following completion of therapy or death. RESULTS: Among 1264 patients with GTN, 191 (15.1%) patients had high-risk GTN and 147 were eligible for the study. Complete sustained remission was ultimately achieved in 87.1% of cases overall, including 68.4% of ultra high-risk GTN (score ≥12). Early death (within 4 weeks of initiating therapy) was significantly associated with ultra high-risk GTN, occurring in 13.8% of these patients (p=0.003). By Cox's proportional hazards regression, factors most strongly related to death were non-molar antecedent pregnancy (RR 4.35, 95% CI 1.71 to 11.05), presence of liver, brain, or kidney metastases (RR 4.99, 95% CI 1.96 to 12.71), FIGO stage (RR 3.14, 95% CI 1.52 to 6.53), and an ultra-high-risk prognostic risk score (RR 7.86, 95% CI 2.99 to 20.71). Median follow-up after completion of chemotherapy was 4 years. Among patients followed to that timepoint, the probability of survival was 90% for patients with high-risk GTN (score 7-11) and 60% for patients with ultra-high-risk GTN (score ≥12). CONCLUSION: Trophoblastic disease centers in developing South American countries have achieved high remission rates in high-risk GTN, but early deaths remain an important problem, particularly in ultra-high-risk GTN.

Low molecular weight hyaluronan induces migration of human choriocarcinoma JEG-3 cells mediated by RHAMM as well as by PI3K and MAPK pathways.

Hyaluronan (HA) is the major glycosaminoglycan present in the extracellular matrix. It is produced by some tumours and promotes proliferation, differentiation and migration among others cellular processes. Gestational trophoblastic disease (GTD) is composed by non-tumour entities, such as hydatidiform mole (HM), which is the most common type of GTD and also malignant entities such as choriocarcinoma (CC) and placental site trophoblastic tumour (PSTT), being CC the most aggressive tumour. Although there is a growing understanding of GTD biology, the role of HA in the pathogenesis of this group of diseases remains largely unknown. The aim of this work was to study the role of HA in the pathogenesis of GTD by defining the expression pattern of HA and its receptors CD44 and RHAMM, as well as to determine if HA can modulate proliferation, differentiation and migration of CC cells. Receptors and signalling pathways involved were also analyzed. We demonstrated that HA and RHAMM are differently expressed among GTD entities and even among trophoblast subtypes. We also showed that HA is able to enhance the expression of extravillous trophoblast markers and also to induce migration of JEG-3 cells, the latter mediated by RHAMM as well as PI3K and MAPK pathways. These findings indicate a novel regulatory mechanism for CC cell biology and also contribute to the understanding of GTD pathophysiology.

Role of Capecitabine in the Management of Gestational Trophoblastic Neoplasia: A Drug for Two Settings.

OBJECTIVE: To evaluate the role of capecitabine in the management of gestational trophoblastic neoplasia (GTN). STUDY DESIGN: The medical records of 155 patients with GTN were reviewed. All patients were treated and followed at our center. RESULTS: All patients were scored and stratified with the FIGO 2000 staging and risk factor scoring system for gestational trophoblastic disease. In the low-risk group (118 patients), 4 selected patients received capecitabine as second line of treatment, with a 75% response rate and long-term disease-free survival, and 1 of those patients needed EMA/CO to achieve cure. The cure rate was 100%. In the high-risk group 37 patients were reviewed. Capecitabine was indicated after EMA/CO or EMA/PE failure in the second, third, or sixth line. Six patients received capecitabine, with a 50% response rate, and remain as long-term survivors. Two patients who progressed with capecitabine were cured with TP/TE and EMA/PE regimens. One patient was refractory to all lines of chemotherapy. CONCLUSION: The use of capecitabine avoids multi-ple drug schemes and further toxicity for patients with curative disease, where long-term effects of therapy should be considered a second target. Its convenient oral route of administration and efficacy make capecitabine a drug to be taken into account in future studies of patients with GTN showing progression to standard regimens. Its use as new regimen in these patients must be evaluated. A greater number of cases and ideally a randomized study is needed to confirm our observation.

Gestational trophoblastic disease: a 21-year review of the clinical experience at an Argentinean public hospital.

OBJECTIVE: To analyze the clinical trends of gestational trophoblastic disease (GTD) in a public hospital of Buenos Aires, Argentina. STUDY DESIGN: A review of the clinical records of 358 patients with a diagnosis of GTD admitted to Durand Trophoblastic Disease Center between 1990 and February 2011 was performed. Features of diagnosis, treatment and follow-up were analyzed. RESULTS: A total of 358 cases of GTD were reviewed. Hydatidiform mole was diagnosed in 340 patients; of those 223 (66%) experienced spontaneous remission after evacuation. Of the 135 patients with persistent gestational trophoblastic neoplasia (GTN), 99 (73%) had low-risk GTN, 32 (26%) had high-risk GTN and 4 had either placental site trophoblastic disease or epithelioid trophoblastic tumor. In the low-risk group the first-line treatment was methotrexate and the second-line treatment was actinomycin D, etoposide, cytoxan, and oncovin (EMA/CO), with a complete response rate of 100%. High-risk patients whose WHO prognostic scores were 7-13 were treated initially with EMA/CO. Patients whose scores were >13 were treated with EMA/PE, where platinum and etoposide replaced oncovin and cytoxan. Salvage therapy in patients with relapse or resistant disease were treated with a wide variety of chemotherapy regimens. The complete response rate was 98.2%. Compliance was 100%. Three patients died. In all cases the outcome was related with inadequate initial treatment. CONCLUSION: This protocol is in agreement with international consensus. It was useful, safe and feasible in our population. The compliance with international guidelines allows reach a successful treatment and follow-up in one Latin-American population.