J Infect Chemother 20 (2014) 26e29
Contents lists available at ScienceDirect
Journal of Infection and Chemotherapy journal homepage: http://www.elsevier.com/locate/jic
Original article
Comparison of two transport systems available in Japan (TERUMO kenkiporter II and BBL Port-A-Cul) for maintenance of aerobic and anaerobic bacteria Daichi Fujimoto a, *, Hiroshi Takegawa b, Asako Doi c, Kenji Sakizono b, Yoko Kotani b, Kanji Miki b, Takuya Naito b, Marie Niki b, Junko Miyamoto b, Koji Tamai a, Kazuma Nagata a, Atsushi Nakagawa a, Ryo Tachikawa a, Kojiro Otsuka a, Nobuyuki Katakami a, Keisuke Tomii a a
Department of Respiratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan Department of Clinical Laboratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan c Department of Infection Control and Prevention, Kobe City Medical Center General Hospital, Kobe, Japan b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 10 April 2013 Received in revised form 18 July 2013 Accepted 19 July 2013
The kenkiporter II (KP II) transport system is commonly used in many hospitals in Japan for transporting bacterial specimens to microbiology laboratories. Recently, the BBL Port-A-Cul (PAC) fluid vial became available. However, no reports thus far have compared the effectiveness of these two transport systems. We chose 4 aerobic and facultative anaerobic bacteria as well as 8 anaerobic organisms, and prepared three strains of each bacterium in culture media for placement into PAC and KP II containers. We compared the effectiveness of each transport system for preserving each organism at 6, 24, and 48 h after inoculation at room temperature. Thirty-six strains out of 12 bacteria were used in this study. The PAC system yielded better recovery in quantity of organisms than the KP II system at 6, 24 and 48 h. More strains were significantly recovered with the PAC system than with the KP II at 24 h (36/36 vs. 23/36, P < 0.001) and 48 h (30/36 vs. 12/36, P < 0.001). The PAC system was better in the recovery of viable organisms counted at 24 and 48 h after inoculation compared with the KP II system. The PAC system may be recommended for the transfer of bacterial specimens in clinical settings. Ó 2013, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Keywords: Aerobic bacteria Anaerobic bacteria Kenkiporter II Port-A-Cul Transportation system
1. Introduction Proper handling of bacterial specimens is crucial for obtaining accurate microbiological test results. Proper transport of specimens is also one of the most important factors in maximizing clinical relevance of microbiological testing [1]. This is especially true for specimen containing anaerobic bacteria, since the protection of anaerobic bacteria from exposure to oxygen is important for their survival [2]. Previous studies supported the use of adequate specimen containers for anaerobic isolates [1,3]. Fluid specimens are often aspirated from the infected tissues at anaerobic environment (such as pyothorax, intra-abdominal or pelvic infections). Aspiration of fluid is better than swab specimens for recovery of anaerobic organisms, and the use of transportation containers to carry aspirated fluids is important in clinical settings * Corresponding author. Department of Respiratory Medicine, Kobe City Medical Center General Hospital, 2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan. Tel.: þ81 783024321; fax: þ81 783027537. E-mail address: [email protected] (D. Fujimoto).
[4]. In many reference laboratories including ours, some samples are submitted for culture after regular working hours of the laboratory. Therefore, transportation containers should be able to maintain organism viability preferably for 24e48 h before the culture process starts. In Japan, a transport container named kenkiporter II (KP II; Terumo Clinical Supply Co., Ltd., Gifu, Japan) is used in many hospitals. More recently, the BBL Port-A-Cul (PAC; Becton Dickinson Japan, Tokyo, Japan) fluid vial became available. Previous reports have demonstrated the usefulness of the PAC system [5,6], however, no comparison of these two transport systems has been made. We therefore sought to determine which of these systems is better in maintaining viability of both aerobic and anaerobic bacteria. 2. Materials and methods 2.1. Bacterial strains We chose 4 aerobic and facultative anaerobic bacteria (Streptococcus pneumonia, Haemophilus influenzae, Escherichia coli, and
1341-321X/$ e see front matter Ó 2013, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jiac.2013.07.008
D. Fujimoto et al. / J Infect Chemother 20 (2014) 26e29
Streptococcus anginosus group), as well as 8 obligate anaerobic organisms (Finegoldia magna, Eubacterium sp., Clostridium sp., Bacteroides fragilis, Bacteroides thetaiotaomicron, Fusobacterium varium, Prevotella melaninogenica, Prevotella bivia) and collected three strains of each bacterium from culture media, which were derived from infected tissue from 3 different patients. As a result, 36 strains of bacteria were used in this study. 2.2. Transport systems used We used the TERUMO kenkiporter II (KP II) and BBL Port-A-Cul (PAC) fluid vial in this study (Fig. 1). There are three types of BBL PAC (transport tubes for swab specimens, jars for tissue specimens, and vials for fluid specimens), and we used the fluid vials in this study. There is solid agar at the bottom of these containers, which contains a balanced formula of reducing agents and inhibits oxygen diffusion by oxidationereduction reactions. As a cover, KP II has a blue cap and PAC fluid vial has a rubber stopper. A syringe with needle is pushed through these to inject fluid specimens directly onto the solid agar surface. By removal of the blue cap of the KP II, we can also insert specimens other than fluids. Since aspiration of fluid is better than swab specimens for recovery of anaerobic organisms, we evaluated the ability to maintain organism viability of the fluid specimens [4]. 2.3. Culture and viability assay The anaerobic bacterial strains were grown on Brucella HK agar (RS) (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) at 37 C for at least 48 h in an anaerobic chamber (TE-HER Anaerobox ANX-3; Hirasawa Works, Tokyo, Japan). The aerobic and facultative anaerobic organisms were grown on Trypticase soy agar II with 5% sheep blood (BA) (Becton Dickinson Japan, Tokyo, Japan) at 37 C in a 5%CO2 incubator for at least 24 h. A suspension of each of the organisms (fluid specimens in this study) was made in sterile saline in the anaerobic chamber, and 1 mL of the each specimen was injected through the blue cap and rubber stopper with a 23-gauge needle syringe and maintained for 6, 24, and 48 h at room temperature to compare the survival. At each time point, an aliquot of each fluid specimen in the containers was taken out and serially diluted by a factor of 10, 100, and 1000 in sterile saline to quantify the number of viable organisms. The fluid specimens were spread over the agar surface with a plate spreader, and then the plates were incubated at 37 C in the appropriate incubator for 48 h. Bacterial recovery was determined by counting the colonies recovered at each of the dilutions. The quantity of organisms recovered is expressed as an average of the duplicate samples evaluated and as a percentage of
Fig. 1. A. The Kenkiporter II (KP II). B. The Port-A-Cul (PAC) vial.
27
the baseline counts (number of colonies at time zero). Detection limit of the quantitative culture is 1 10 CFU/mL. Three strains per bacterium were investigated by the same method, and the number of strains recovered was compared. 2.4. Comparison and statistical analysis The relationship between dichotomous variables was analyzed using c2 test or Fisher’s exact test, whichever was appropriate. Pvalues of
Contents lists available at ScienceDirect
Journal of Infection and Chemotherapy journal homepage: http://www.elsevier.com/locate/jic
Original article
Comparison of two transport systems available in Japan (TERUMO kenkiporter II and BBL Port-A-Cul) for maintenance of aerobic and anaerobic bacteria Daichi Fujimoto a, *, Hiroshi Takegawa b, Asako Doi c, Kenji Sakizono b, Yoko Kotani b, Kanji Miki b, Takuya Naito b, Marie Niki b, Junko Miyamoto b, Koji Tamai a, Kazuma Nagata a, Atsushi Nakagawa a, Ryo Tachikawa a, Kojiro Otsuka a, Nobuyuki Katakami a, Keisuke Tomii a a
Department of Respiratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan Department of Clinical Laboratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan c Department of Infection Control and Prevention, Kobe City Medical Center General Hospital, Kobe, Japan b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 10 April 2013 Received in revised form 18 July 2013 Accepted 19 July 2013
The kenkiporter II (KP II) transport system is commonly used in many hospitals in Japan for transporting bacterial specimens to microbiology laboratories. Recently, the BBL Port-A-Cul (PAC) fluid vial became available. However, no reports thus far have compared the effectiveness of these two transport systems. We chose 4 aerobic and facultative anaerobic bacteria as well as 8 anaerobic organisms, and prepared three strains of each bacterium in culture media for placement into PAC and KP II containers. We compared the effectiveness of each transport system for preserving each organism at 6, 24, and 48 h after inoculation at room temperature. Thirty-six strains out of 12 bacteria were used in this study. The PAC system yielded better recovery in quantity of organisms than the KP II system at 6, 24 and 48 h. More strains were significantly recovered with the PAC system than with the KP II at 24 h (36/36 vs. 23/36, P < 0.001) and 48 h (30/36 vs. 12/36, P < 0.001). The PAC system was better in the recovery of viable organisms counted at 24 and 48 h after inoculation compared with the KP II system. The PAC system may be recommended for the transfer of bacterial specimens in clinical settings. Ó 2013, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Keywords: Aerobic bacteria Anaerobic bacteria Kenkiporter II Port-A-Cul Transportation system
1. Introduction Proper handling of bacterial specimens is crucial for obtaining accurate microbiological test results. Proper transport of specimens is also one of the most important factors in maximizing clinical relevance of microbiological testing [1]. This is especially true for specimen containing anaerobic bacteria, since the protection of anaerobic bacteria from exposure to oxygen is important for their survival [2]. Previous studies supported the use of adequate specimen containers for anaerobic isolates [1,3]. Fluid specimens are often aspirated from the infected tissues at anaerobic environment (such as pyothorax, intra-abdominal or pelvic infections). Aspiration of fluid is better than swab specimens for recovery of anaerobic organisms, and the use of transportation containers to carry aspirated fluids is important in clinical settings * Corresponding author. Department of Respiratory Medicine, Kobe City Medical Center General Hospital, 2 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan. Tel.: þ81 783024321; fax: þ81 783027537. E-mail address: [email protected] (D. Fujimoto).
[4]. In many reference laboratories including ours, some samples are submitted for culture after regular working hours of the laboratory. Therefore, transportation containers should be able to maintain organism viability preferably for 24e48 h before the culture process starts. In Japan, a transport container named kenkiporter II (KP II; Terumo Clinical Supply Co., Ltd., Gifu, Japan) is used in many hospitals. More recently, the BBL Port-A-Cul (PAC; Becton Dickinson Japan, Tokyo, Japan) fluid vial became available. Previous reports have demonstrated the usefulness of the PAC system [5,6], however, no comparison of these two transport systems has been made. We therefore sought to determine which of these systems is better in maintaining viability of both aerobic and anaerobic bacteria. 2. Materials and methods 2.1. Bacterial strains We chose 4 aerobic and facultative anaerobic bacteria (Streptococcus pneumonia, Haemophilus influenzae, Escherichia coli, and
1341-321X/$ e see front matter Ó 2013, Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jiac.2013.07.008
D. Fujimoto et al. / J Infect Chemother 20 (2014) 26e29
Streptococcus anginosus group), as well as 8 obligate anaerobic organisms (Finegoldia magna, Eubacterium sp., Clostridium sp., Bacteroides fragilis, Bacteroides thetaiotaomicron, Fusobacterium varium, Prevotella melaninogenica, Prevotella bivia) and collected three strains of each bacterium from culture media, which were derived from infected tissue from 3 different patients. As a result, 36 strains of bacteria were used in this study. 2.2. Transport systems used We used the TERUMO kenkiporter II (KP II) and BBL Port-A-Cul (PAC) fluid vial in this study (Fig. 1). There are three types of BBL PAC (transport tubes for swab specimens, jars for tissue specimens, and vials for fluid specimens), and we used the fluid vials in this study. There is solid agar at the bottom of these containers, which contains a balanced formula of reducing agents and inhibits oxygen diffusion by oxidationereduction reactions. As a cover, KP II has a blue cap and PAC fluid vial has a rubber stopper. A syringe with needle is pushed through these to inject fluid specimens directly onto the solid agar surface. By removal of the blue cap of the KP II, we can also insert specimens other than fluids. Since aspiration of fluid is better than swab specimens for recovery of anaerobic organisms, we evaluated the ability to maintain organism viability of the fluid specimens [4]. 2.3. Culture and viability assay The anaerobic bacterial strains were grown on Brucella HK agar (RS) (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) at 37 C for at least 48 h in an anaerobic chamber (TE-HER Anaerobox ANX-3; Hirasawa Works, Tokyo, Japan). The aerobic and facultative anaerobic organisms were grown on Trypticase soy agar II with 5% sheep blood (BA) (Becton Dickinson Japan, Tokyo, Japan) at 37 C in a 5%CO2 incubator for at least 24 h. A suspension of each of the organisms (fluid specimens in this study) was made in sterile saline in the anaerobic chamber, and 1 mL of the each specimen was injected through the blue cap and rubber stopper with a 23-gauge needle syringe and maintained for 6, 24, and 48 h at room temperature to compare the survival. At each time point, an aliquot of each fluid specimen in the containers was taken out and serially diluted by a factor of 10, 100, and 1000 in sterile saline to quantify the number of viable organisms. The fluid specimens were spread over the agar surface with a plate spreader, and then the plates were incubated at 37 C in the appropriate incubator for 48 h. Bacterial recovery was determined by counting the colonies recovered at each of the dilutions. The quantity of organisms recovered is expressed as an average of the duplicate samples evaluated and as a percentage of
Fig. 1. A. The Kenkiporter II (KP II). B. The Port-A-Cul (PAC) vial.
27
the baseline counts (number of colonies at time zero). Detection limit of the quantitative culture is 1 10 CFU/mL. Three strains per bacterium were investigated by the same method, and the number of strains recovered was compared. 2.4. Comparison and statistical analysis The relationship between dichotomous variables was analyzed using c2 test or Fisher’s exact test, whichever was appropriate. Pvalues of
