Evaluation of BacT/Alert FAN Plus Bottles for the Culture of Peritoneal Dialysate / 대한임상미생물학회지

BACKGROUND: A major complication of peritoneal dialysis (PD) is peritonitis, and bacterial culture of PD effluent in a blood culture bottle is the preferred technique for diagnosis of peritonitis. In this study, we compared dialysate inoculation and culture using the BacT/AlerT® Fastidious Antimicrobial Neutralization Plus blood culture bottles (FAN Plus; bioMérieux, France) to the conventional centrifugation culture method.METHODS: A total of 170 PD effluents were simultaneously processed by the conventional centrifugation culture method and by culture using FAN Plus media with two different inoculation procedures: inoculation after centrifugation and direct bedside inoculation.RESULTS: Of the 52 cultures that were positive on at least one of the culture methods, 27 samples were positive on conventional centrifugation. However, 46 samples showed growth following inoculation into the FAN Plus media after centrifugation, and 47 samples were positive on the direct FAN Plus inoculation method. Using the case definition for PD peritonitis to classify samples, sensitivity of the conventional method was 50.0% (95% CI, 33.7–66.3%), whereas the sensitivity of the FAN Plus media was 78.9% (95% CI, 62.2–89.9%) by inoculation after centrifugation and 86.8% (95% CI, 71.1–95.1%) by direct inoculation. Use of both inoculation methods with FAN Plus media resulted in 92.1% sensitivity (95% CI, 89.2–99.9%).CONCLUSION: Culture using FAN Plus media demonstrated a superior bacterial recovery rate to the conventional centrifugation culture method. A combination of the two inoculation methods with FAN Plus media is recommended for the best diagnostic yield, while direct inoculation alone can be useful due to its simplicity and cost-effectiveness.

Nuevas herramientas para el diagnóstico de la tuberculosis / New tools for tuberculosis diagnosis

Introducción: en las últimas décadas se han desarrollado nuevas herramientas para disminuir el tiempo de diagnóstico de las infecciones por Mycobacterium tuberculosis. Objetivo: introducir nuevas herramientas para la identificación de M. tuberculosis y comparar los resultados con el cultivo en Löwenstein Jensen. Métodos: se estudiaron 1 368 muestras recibidas en el Laboratorio Nacional de Referencia de Tuberculosis del Instituto de Medicina Tropical Pedro Kourí, de agosto 2010 - agosto 2014. Las muestras después de procesadas fueron inoculadas en paralelo en Löwenstein Jensen y en BacT ALERT. Los resultados se ana­lizaron y compararon con relación al total de aislamientos, tiempo de detección de crecimiento y tasa de contaminación, se calcularon además los indicadores de desempeño del BacT ALERT. Resultados: por Bact/ ALERT se identificó Mycobacterium tuberculosis en 126 (98,5 por ciento) muestras y 116 (88,5 por ciento) por el Löwenstein Jensen. El tiempo de detección de crecimiento de Mycobacterium tuberculosis por el BacT/ ALERT fue de 16,6 días, dos veces menor que el obtenido por el Löwenstein Jensen (35,5 días). La tasa de contaminación por el Bact/ ALERT y Löwenstein Jensen fue de 11 por ciento y 7,8 por ciento, respectivamente. La sensibilidad, especificidad e índice de Youden fue de 99,1 por ciento, 99,0 por ciento y 0,98, respectivamente; y el índice de validez del 99 por ciento. Conclusiones: el sistema Bact/ ALERT resultó un método útil porque acortó significativamente el tiempo de diagnóstico de la tuberculosis permitiendo comenzar el tratamiento de forma oportuna, sobre todo en pacientes con baciloscopia negativa. El uso combinado del Löwenstein Jensen y medio líquido aseguró la recuperación del total de cepas de M. tuberculosis(AU)

Background: in recent decades, new tools have been developed to decrease the time of diagnosis of infections with Mycobacterium tuberculosis. Objective: to introduce the new tools for identification of M. tuberculosis and compare the results with culture in Löwenstein Jensen. Methods: 1 368 samples received at the National Tuberculosis Reference Laboratory of the IPK from August 2010 to August 2014. After samples processed were inoculated in parallel on Löwenstein Jensen and BacT ALERT. The results obtained are analyzed and compared with respect to the total isolates, time detection of growth and contamination rate, the performance indicators of BacT ALERT also calculated. Results: by Bact / ALERT were identified Mycobacterium tuberculosis in 126 (98.5 percent) samples and 116 (88.5 percent) by Löwenstein Jensen. The time detection of growth of Mycobacterium tuberculosis by BacT / ALERT was 16.6 days, two times lower than that obtained by the Löwenstein Jensen (35.5 days). The contamination rate by Bact / ALERT and Löwenstein Jensen was 11 percent and 7.8 percent, respectively. The sensitivity, specificity and Youden index was 99.1 percent, 99.0 percent and 0.98, respectively; and the validity index was 99 percent. Conclusions: bact / ALERT system proved a useful method because it significantly shortened the time of tuberculosis diagnosis and start allowing treatment in a timely manner, especially in smear-negative patients. The combined use of liquid medium and Löwenstein Jensen assured recovery of all strains of Mycobacterium tuberculosis(AU)

Comparison of Methods for Detecting Bacterial Contamination in Platelet Concentrates / 대한수혈학회지

BACKGROUND: Bacterial contamination of platelets represents the highest infectious risk for a transfusion. In this study, we evaluated 2 culture-based systems that have been approved by the US FDA for bacterial screening. METHODS: Platelet concentrates were inoculated with 5 bacterial species to give a final concentration of 10(0), 10(1) and 10(2) CFU/mL. Samples for culture were taken immediately after inoculation (0 hr sample) and after 24 hrs (24 hr sample). For the BacT/ALERT 3D system, a 10 mL sample was inoculated into an aerobic culture bottle and incubated for 7 days. For the Pall eBDS system, 3 mL samples were taken from the 0 hr and 24 hr samples, respectively. The samples were incubated for 24 hrs and 30 hrs. RESULTS: Both systems detected all inoculated units both in the 0 hr and 24 hr samples, except for units inoculated with K. pneumoniae. Eleven units out of 30 units inoculated with K. pneumoniae were detected by the BacT/ALERT 3D system in the 24 hr samples. The Pall eBDS system detected 8 of 30 units in the 24 hr samples. CONCLUSION: Implementation of either system will decrease the risk of transfusing bacterially contaminated platelets. However, testing for bacterial contamination will not completely prevent septic transfusion reactions; pathogen inactivation that is now available should also be considered as an alternative method to reduce the risk of bacterial contamination.

Standardization of first and second-line antitubercular susceptibility testing using BacT Alert 3D system: a report from a tertiary care centre in India

Resurgence of multidrug resistant tuberculosis has lead to demand for rapid susceptibility testing. Conventional methods take > 3 weeks and are tedious. Automated methods have superseded them for first line drug susceptibility testing. An attempt was made to standardize first and second line susceptibility testing using the BacT Alert 3D system (Biomerieux). And compare results with Lowenstein Jensen's (LJ) method. 121 isolates of Mycobacterium tuberculosis, 67 pulmonary and 54 extra pulmonary were subjected to sensitivity to first and second line drugs. Multidrug resistance was detected equally by both methods at 15.7 percent. 100 percent agreement was observed between the two methods for aminoglycosides, rifampicin, ethionamide and ciprofloxacin. 91.5 percent agreement was observed for isoniazid, 85 percent for pyrazinamide and 72.4 percent for ethambutol. The time taken by LJ method was 18-32 days and BacT Alert 3D system took 4-12 days. In the lesser developed nations where tuberculosis is rampant a rapid effective method for confirming multidrug resistant tuberculosis is definitely desirable and the BacT Alert 3D system was found an effective method when compared to the 'gold standard' LJ proportion.