Detection of Listeria spp. Compact Dry LS
Fe Featu ture Compact Dry L LS Com ompact Dry LS S is s a si simplified m medium t to o identify List steria sp spp. by the c com ombination on of of se selective age gents s and chrom omog ogenic su subst strates. s. Sample : food and environmental s sample pH : 7.2±0.2 incubation : at 35 or 37 ℃ ±1 ℃ , 24hr incubation, if necessary, additional 24hr colony color: light blue / blue colonies storage : one year after manufacturing at Room temperture patent : pending
Benefi Be fit Compact Dry L LS Any foo An ood, , beverage ge and water is s pos ossi sible as s sa sample. Sample : S Solid food Liquid food Raw m material Animal feed Beverage Be Wa Water Environmental test ( (swab) Identification Id on and e enumeration on of of List steria sp spp. Prod oduced by IS ISO 9001 regi gist stered factor ory
Exa xamp mple le of of natu tura rall lly con onta tami minati tion on Compact Dry L LS Listeri ria a spp. forms light blue/blu lue e colonies s on the Compact t Dry LS. S. *identi tify fy Listeria spp. only, NOT identify fy L. monocyt ytoge ogene nes. s. ↑ Close- up ↓ *photos : The samples are commercial fish sausages from two different companies.
Proc Pr oced edur ure (applied ed with ISO SO11290-2) 2) Compact Dry L LS Sampling from surfaces Test portion using swabs (food and liquid) Diluent for the preparation Resuscitation for 1hr at 20 ℃ of the initial suspension BPW Resuscitation for 1hr at 20 ℃ #05131 Buffered Peptone Water “Nissui” 300g Compact Dry LS at 35 or 37 ℃ for 24hr Light blue/blue colonies Identification and enumeration of Listeria spp. Confirmation of Listeria spp. : -inoculation on TSYEA and incubation for 16 – 24 hr at 35C or 37C; -catalase reaction; -Gram staining; -motility test (if necessary). Confirmation of Listeria monocytogenes : -haemolysis test; -carbohydrate utilization; -CAMP test.
Se Sele lecti tivit ity of of se sele lecte ted d st strain ins Compact Dry L LS Inoculation of 10 7 -10 9 cfu/mL, incubation : 37degreeC, 24hr (+:growth,-:no-growth, cell color:colony color, number: CFU) SCD CD LS Oxford ALOA SCD CD LS Oxford ALOA strain ( more than two ) logCFU logCFU Colony Colony Colony Colony Colony Colony strain ( more than two ) /mL /mL color logCFU/mL color logCFU/mL color logCFU/mL color logCFU/mL color logCFU/mL color logCFU/mL L. monocytogenes ( 8 ) 8.5 + 9.1 + 9.2 + 9.0 6.6 - - + >5.0 S. xylosus L. grayi ( 2 ) 8.5 + 8.8 + 8.5 + 8.0 7.6 - - - S. thermophilus L. innocua ( 2 ) 9.4 + 9.4 + 9.4 + 9.4 C. albicans ( 2 ) 6.6 - + >6.0 - 9.4 + 9.0 + 8.8 + 9.3 7.0 - - - L. ivanovii [slow growth] S. cerevisiae L. welshimeri ( 2 ) 9.1 + 9.0 + 8.9 + 9.2 8.5 - - - A. hydrophila 5.7 - - - 8.5 - - - B. cereus A. denitrificans 7.1 - * >5.0 + >3.0 + >5.0 7.6 + >7.0 + >7.0 - B. licheniformis A. xylosoxidans 6.6 - - - 8.7 - - - B. subtilis A. faecalis 7.1 - - - 8.8 - - - C. minutissimum C. amalonaticus 7.7 - - - 8.5 - - - C. renale C. freundii 7.5 - - - 8.4 - - - C. xerosis C. koseri 7.5 - * >6.0 - - 8.1 - - - E. avium E. aerogenes 7.4 - - - 8.1 - - - E. durans E. amnigenus 7.5 - * >6.0 - - 8.6 - - - E. casseliflavus E. cloacae E. faecalis ( 2 ) 8.5 - * >7.0 - - E. intermedius ( 2 ) 8.6 - - - 8.5 - - - 7.7 - - - E. faecium E. sakazakii 6.8 - - - 8.3 - - - E. gallinarum E. blattae 7.7 - * >6.0 - - E. coli ( 4 ) 8.4 - - - E. hirae 7.9 - * >7.0 - - E. coli O157 ( 3 ) 8.6 - - - E. mundtii 7.0 - * >6.0 - - E. fergusonii ( 2 ) 8.0 - - - E. raffinosus 6.7 - - - 8.3 - - - L. lactis E. hermannii 8.1 - - - 8.5 - - - L. citreum H. alvei 8.0 - - - 8.5 - - - L. mesenteroides K. oxytoca 7.5 - - - 8.6 - - - M. luteus K. ozaenae 7.9 - - - 8.4 - - - P. acidilactici K. pneumoniae S. aureus ( 5 ) 7.8 - - + >6.0 7.5 - - - K. ascorbata 8.0 + >5.0 + >5.0 + >6.0 7.5 - - - S. aureus MRSA K. cryocrescens 6.6 - - + >4.0 8.7 - - - S. auricularis M. morganii 8.2 - - - 8.5 + >7.0 - - S. capitis P. mirabilis S. epidermidis ( 2 ) 7.3 - - - 8.7 - - - P. vulgaris 6.5 - - - P. aeruginosa ( 4 ) 8.5 + >7.0 - - S. haemolyticus 7.3 - - - 7.9 - - - S. hominis P. putida 7.5 - - + >5.0 7.9 - - - S. intermedius R. aquatilis 7.3 - - - 8.8 - - - S. lentus S. Typhimurium 7.4 - + >5.0 + >4.0 8.8 - - - S. saprophyticus S. Choleraesuis 7.5 - - + >5.0 7.3 - - - S. sciuri S. fonticola 7.8 - - - 8.0 - - - S. simulans S. liquefaciens 7.5 - - - S. marcescens ( 2 ) 7.8 + >7.0 - - S. warneri *:The plate color is changed, no growth
Inoc ocula late ted pack k of of Lis iste teri ria mo monoc ocyto toge genes Compact Dry L LS at 37 degree C, 24hr incubation ( Log : LogCFU/g ) L.monocytog ogenes CFU/g L.monocytog ogenes CFU/g food food inoc oculation ion (10 x /g) CD LS Oxfo ford rd ALOA inoc oculation ion(1 (10 x /g) CD LS Oxfo ford rd ALOA Natural ral cheese 1.0 85 85 50 50 100 barbecued pork 2.0 200 150 200 2.0 240 450 250 3.0 1675 1550 1650 3.0 3500 3450 3200 4.0 14150 12000 11750 cheese 1.0 170 150 150 Sausage (1) 1.0 120 50 50 100 2.0 175 150 300 2.0 220 200 200 3.0 1035 1100 1000 3.0 4950 4350 6150 Italian cheese 2.0 85 85 100 100 Sausage (2) 1.0 115 100 100 3.0 1070 1700 1450 2.0 150 150 200 4.0 9300 7000 5250 Cooked d young bamboo 2.0 120 100 150 Chame memb mbert rt cheese 2.0 305 450 50 50 3.0 790 950 1200 3.0 1610 1950 1900 Salted cod roe 1.0 90 90 100 100 4.0 15950 14850 17200 2.0 135 250 300 Smoked cheese (1) 1.0 125 50 50 50 50 3.0 3500 2850 4000 2.0 140 100 100 Cod roe in soy sauce 2.0 110 100 100 3.0 805 600 800 3.0 185 100 100 Smoked cheese (2) 2.0 105 100 150 Vinegare ared jellyfi yfish 1.0 90 90 50 50 50 50 2.0 125 100 50 50 2.0 165 200 250 Cheese and salami mi 1.0 130 200 150 3.0 745 950 1850 2.0 300 350 450 Drie ied young sardin ines 1.0 105 50 50 50 50 Fish sausage 3.0 935 1050 1050 2.0 145 100 300 4.0 10650 9150 9750 3.0 1745 2300 2050 4.0 8850 10050 9550 whit itebait bait 2.0 170 100 150 sala lami mi 1.0 100 100 50 50 3.0 1995 1700 1950 2.0 135 100 250 4.0 25800 24250 25350 3.0 3300 1450 2300 Salmon on flake 2.0 180 100 250 Sliced ham (1) 1.0 100 50 50 100 3.0 1450 850 1400 2.0 730 1000 700 4.0 16800 12550 14200 3.0 11050 10250 10800 Mixed d salad 1.0 130 50 50 50 50 Sliced ham (2) 2.0 220 50 50 250 2.0 130 50 50 50 50 Raw ham 1.0 135 100 100 3.0 465 500 400 2.0 310 200 400 Vegetable ble 1.0 400 150 200 3.0 1510 2050 2300 2.0 545 450 250 Roast ham 2.0 225 100 100 3.0 2105 2900 2950 3.0 2020 2100 1900 Macaron roni salad 3.0 135 100 200 4.0 22600 21500 21650 Black soybean 2.0 180 50 50 100
Co Corr rrel elat atio ion n Dat ata Compact Dry L LS Compact Dry LS vs. ISO11290-2 (ALOA agar) 5,00 Compact Dry LS (LogCFU/g) y = 0.893x + 0.3695 4,50 r = 0.973 4,00 n = 70 3,50 3,00 2,50 2,00 1,50 1,00 1,00 2,00 3,00 4,00 5,00 ISO11290-2 (ALOA agar)(LogCFU/g)
Corr Co rrel elat atio ion n Dat ata a (2 (2) Compact Dry L LS Compact Dry LS vs. ISO11290-2 (Oxford agar) 5,00 Compact Dry LS (LogCFU/g) y = 0.9074x + 0.28 4,50 r = 0.965 4,00 n = 70 3,50 3,00 2,50 2,00 1,50 1,00 1,00 2,00 3,00 4,00 5,00 ISO11290-2 (Oxford agar)(LogCFU/g)
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