Enumeration of viable CD34+ cells in cord blood using a novel stem cell enumeration kit

Objective To assess the detection performance of the hematopoietic stem cell enumeration kit developed by BD Biosciences. Methods Cord blood samples were prepared using a hematopoietic stem cell enumeration kit developed by BD Biosciences and Stem-Kit reagents from Beckman Coulter. CD34+ cells were enumerated using a BD FACSCanto instrument and FACSDiva software. Results A total of 519 samples were analyzed in this study. The hematopoietic stem cell enumeration kit developed by BD Biosciences yielded absolute counts of CD34-positive cells that were on average 8.7% lower than Beckman Coulter Stem-Kit reagents (range: −5.7% to−14.7%). The BD Biosciences kit yielded relative counts that were on average 9.9% higher compared with Beckman Coulter Stem-Kit reagents (range: −2.1% to +13.8%). The intraclass correlation coefficients for absolute and relative counts of CD34-positive cells were 0.9967 (95% confidence interval [CI]: 0.9961–0.9972) and 0.9512 (95% CI: 0.9423–0.9587) for the BD Biosciences and Beckman Coulter kits, respectively. Conclusions The hematopoietic stem cell enumeration kit developed by BD Biosciences can be used to enumerate CD34-positive stem cells from cord blood samples.

Simultaneous Isolation and Enumeration of Virulent Vibrio Cholerae and Vibrio Vulnificus using an Advanced MPN-PCR Method

Vibrio cholerae and Vibrio vulnificus are one of the critical foodborne pathogens that need to be intensively controlled their infection as a result of the intake and distribution of seafood, especially raw oysters. For this reason, various methods have already been developed for the detection and enumeration of these bacteria. The most probable number (MPN)-PCR (polymerase chain reaction) method is commonly used with the selective-differential medium for the efficiency and convenience of cell enumeration. One of the most frequently used for the detection of Vibrio spp. is Thiosulfate-Citrate-Bile salts-Sucrose (TCBS) agar. But this selective-differential medium can fail to distinguish between V. cholerae, V. vulnificus, and Vibrio alginolyticus. For this reason, the conventional MPN-PCR method with TCBS medium for the detection of Vibrio spp. has a problem that processing PCR to the two-times. This study suggests a simple and minimized detection method using one-time PCR and non-NaCl Luria-Bertani (LB-0) medium culture. This detection method is based on the difference in salt requirement between V. cholerae and V. vulnificus. Employing the developed methodology, the simultaneous cell enumeration of V. cholerae and V. vulnificus can be possible at a low cost. Furthermore, this study proposes a new specific primer to detect virulence-related genes from V. cholerae and V. vulnificus. This advanced MPN-PCR method was verified using bioaccumulated pacific oysters (Crassostrea gigas) by V. cholerae and V. vulnificus.

Abundance interaction in Candida albicans and Candida glabrata mixed biofilms under diverse conditions

Candida albicans and Candida glabrata are frequently coisolated from the oral cavity in immunosuppressive or immunocompromised individuals. Their relationship is usually defined as competition as C. glabrata can inhibit growth of C. albicans in cohabitation. In this study, eight C. albicans isolates as well as two C. glabrata strains were used to investigate the effects of culture medium (Roswell Park Memorial Institute [RPMI]-1640, YPD, YND), incubation time (24 h, 48 h, 72 h, 96 h), initial inoculum (C. glabrata: C. albicans = 2:1, 1:1, 1:2), and medium state (static and dynamic states) on viable cell enumeration and relative abundance in both Candida SB and MB. The results showed that in most cases, C. glabrata and C. albicans SB and MB flourished in RPMI-1640 at 24 h under dynamic state compared with other conditions. Except YPD medium, there were high proportions of preponderance of C. albicans over C. glabrata in MB compared with SB. High initial inoculum promoted corresponding Candida number in both SB and MB and its abundance in MB relative to SB. This study revealed an impact of several environmental conditions on the formation of C. albicans and C. glabrata SB and MB and their abundance in MB in comparison with SB, deepening our understanding of both Candida interaction and their resistance mechanism in MB. Lay Summary This study described the effects of diverse experimental conditions on the numbers of Candida albicans and Candida glabrata single biofilms and mixed biofilms and their abundance.