TY - JOUR
T1 - A high-throughput qPCR system for simultaneous quantitative detection of dairy Lactococcus lactis and Leuconostoc bacteriophages
AU - Muhammed, Musemma Kedir
AU - Krych, Lukasz
AU - Nielsen, Dennis Sandris
AU - Vogensen, Finn Kvist
PY - 2017
Y1 - 2017
N2 - Simultaneous quantitative detection of Lactococcus (Lc.) lactis and Leuconostoc species bacteriophages (phages) has not been reported in dairies using undefined mixed-strain DL-starters, probably due to the lack of applicable methods. We optimized a high-throughput qPCR system that allows simultaneous quantitative detection of Lc. lactis 936 (now SK1virus), P335, c2 (now C2virus) and Leuconostoc phage groups. Component assays are designed to have high efficiencies and nearly the same dynamic detection ranges, i.e., from 1.1 x 105 to 1.1 x 101 phage genomes per reaction, which corresponds to 9 x 107 to 9 x 103 phage particles mL-1 without any additional up-concentrating steps. The amplification efficiencies of the corresponding assays were 100.1±2.6, 98.7±2.3, 101.0±2.3 and 96.2±6.2. The qPCR system was tested on samples obtained from a dairy plant that employed traditional mother-bulk-cheese vat system. High levels of 936 and P335 phages were detected in the mother culture and the bulk starter, but also in the whey samples. Low levels of phages were detected in the cheese milk samples.
AB - Simultaneous quantitative detection of Lactococcus (Lc.) lactis and Leuconostoc species bacteriophages (phages) has not been reported in dairies using undefined mixed-strain DL-starters, probably due to the lack of applicable methods. We optimized a high-throughput qPCR system that allows simultaneous quantitative detection of Lc. lactis 936 (now SK1virus), P335, c2 (now C2virus) and Leuconostoc phage groups. Component assays are designed to have high efficiencies and nearly the same dynamic detection ranges, i.e., from 1.1 x 105 to 1.1 x 101 phage genomes per reaction, which corresponds to 9 x 107 to 9 x 103 phage particles mL-1 without any additional up-concentrating steps. The amplification efficiencies of the corresponding assays were 100.1±2.6, 98.7±2.3, 101.0±2.3 and 96.2±6.2. The qPCR system was tested on samples obtained from a dairy plant that employed traditional mother-bulk-cheese vat system. High levels of 936 and P335 phages were detected in the mother culture and the bulk starter, but also in the whey samples. Low levels of phages were detected in the cheese milk samples.
U2 - 10.1371/journal.pone.0174223
DO - 10.1371/journal.pone.0174223
M3 - Journal article
C2 - 28339484
AN - SCOPUS:85016154722
SN - 1932-6203
VL - 12
JO - PLOS ONE
JF - PLOS ONE
IS - 3
M1 - e0174223
ER -