摘要:

Rapid methods and automation in microbiology comprise a dynamic area of research and study. the field encompasses a wide variety of subjects in theoretical and applied microbiology. This article traces the major developments of this field since the late 1960s, detailed with dates and locations of major international meetings on the subject as well as listing of major books, proceedings, and articles concerning this topic. the article should be of interest to all scientists who want to know the key developments, current status, and possible future trends of the field.

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00066.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The growth ofListeria monocytogenesand otherListeriaspecies (L. innocua, L. ivanovii, L. seeligeri, andL. welshimeri) (initial inocula of 103‐103CFU/mL) at 35C in the absence (as controls) or presence of OxyraseTMenzyme was studied using Fraser broth. the results showed that the generation times of these organisms ranged from 35.5 to 54.4 min for the studies with OxyraseTMand from 39.4 to 72.7 min for the studies without OxyraseTM. the degree of growth enhancement by OxyraseTMwas dependent on species/strains ofListeriaand population of inocula. an earlier initial increase in populations of three strains ofL. monocytogenesat 35C was observed in Fraser broth with OxyraseTMadded, and the lag phase durations computed for LM 101M, LM 103M, and Scott A were shown to be 3.2, 1.6, and 2.4 h shorter in the presence of OxyraseTMthan in the controls. For the range of 0 to 0.8 unit/mL added OxyraseTMtested, the growth ofL. monocytogenesdemonstrated a dose‐response to the amount of OxyraseTMin the broth sys

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00067.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The polymerase chain reaction (PCR) was used to amplify a 1340‐bp fragment from the toxigenicClostridium botulinumtype A chromosome. Two oligonucleotide primers were synthesized to bracket the sequence coding for most of the type A toxin light chain (1340‐bp in size). the PCR amplified a 1340‐bp fragment from the DNA of all elevenC. botulinumtype A strains tested. In contrast, no DNA fragments were amplified fromC. botulinumtypes B, E, and F or from the other Clostridial chromosomal DNA examined. the products amplifed from botulinal type A strains were digested to produce fragments of the size predicted from the known location of theHinddIII sites within the toxin gene sequence. When used as a DNA probe, the 1340‐bp PCR generated fragment from type A C.botulinumstrain 73A hybridized to the PCR products from all 11 type A botulinal strains and to type A thromosomal DNA prepa

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00068.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Tristimulus reflectance colorimetry (RC) is a rapid method with which microbial activities can be monitored by the mediation of dye pigmentation changes. Dyes that produce color changes because of shifts of pH and oxidation/reduction (O/R) potential or free amino groups can be used.To estimate total microbial numbers from pure coliform andListeriacultures and from minced beef samples, the appropriate color endpoint values were selected for each sample type (b*=+2 for coliforms,L*=+ 11 forListeria, and a*=+ 4 and a*=+ 6 for minced beef samples) and used to estimate color detection times (CDTs). the regression lines of data between aerobic plate count (APC; conventional and also Spiral System with minced beef samples) and RC were calculated. Reliability of the calibration lines was good; r = 0.90–0.99 for bacterial cultures and r = 0.82 (0.80) for minced beef (a*=+ 4) and r = 0.80 (0.78) for minced beef (a*=+6) when RC was compared with APC (Spiral).The calibration line for minced beef samples (1/10 dilution) could be used to classify samples above and below a certain specified microbial level (e.g., log 6.0 CFU/g) and to marginal samples. Using these scheme with a*=+4 as the color endpoint value, 70% of the tested 40 minced beef samples were correctly classified. the calibration line could also be used to approximate plate count determinations (e.g., CDT of 12 h will result in an estimated count of log 5.9 CFU/g).Results were obtained in shorter time (ranging from 0–15 h forEnterobacter aerogenesandE. coli, from 2–17 h forH. alvei, from 1.5–25 h forListeria monocytogenesATCC 35152 and Scott A, from 6–39 h for slowly growingL. monocytogenesATCC 19919, and from 2–15 h for minced beef, depending on the initial cell concentration) than required by conventional plate counting (24 h for coliforms, 24–48 h forListeria, and 48 h for total counts). Time for further confirmation varies according to bacterial species. the RC technique was sensitive for low levels (as low as 1 CFU/mL) of microbes.Colorimetric microtest plate technology provided in the OmnispecTMBioactivity Monitor System simplifies the analysis, saves labor and materials, and provides

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00069.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A fluorescent assay employing polystyrene beads coated with antibody to a common structural antigen (CSA) of salmonellae has been developed to detect the presence ofSalmonella.This sensitive technique is very fast, relatively simple and with further testing may be suitable for screening food products as well as clinical diagnostics. Comparison was made with a commercially availableSalmonellaantigen capture enzyme immunoassay (EIA). As little as one single colony‐forming unit (CFU) could be detected by fluorescence after only 16 h of enrichment. the procedure requires only 1 h to run and uses proportionately smaller volumes of sample and reagents than EI

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00070.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A microcolony‐immunoblot technique (MCIBI) was developed to directly enumerate, in less than 24 h, very low numbers ofListeria monocytogenes(8–12 colony forming units: CFU/g or mL) inoculated into foods. Four meat and poultry and two dairy products were artificially inoculated withL. monocytogenesV7 diluted and plated on Oxford agar medium. Each plate was overlaid with an Immobilon‐P membrane and incubated for 18–20 h at 37C. Blot‐transferred colonies on these membranes were probed with C11E9 monoclonal antibody (MAb) and developed using peroxidase conjugated goat antimo use Ig G and a water insoluble substrate (3,3‐diaminobenzidin tetrahydmchloride; (DAB‐HCI), Nickel chloride and H2O2). the MCIBT gaveL. monocytogenescounts that were not significantly lower than direct colony counts on selective agars. This technique allowed the recovery of 94–100% ofL. monocytogenescells inoculated into foods containing natural background flora counts of 3 × 104to 8 × 106CFU/g or mL. Using a 2 h resuscitation period on nonselective agar before overlay with Oxford media, the MCIBT allowed detection of sublethally heat injured c

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00071.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

DNA probes specific forCampylobacterjejuni have been developed. A genomic library ofC. jejuniwas constructed and screened with32P‐labeled genomic DNA fromC. jejuniandC. coliby colony hybridization. Several clones that reacted only withC. jejunibut not withC. coliwere selected. Two DNA inserts (1.5 kb and 0.8 kb) were isolated from the positive clones. A modified Southern hybridization technique indicated that these two32P‐labeled DNA inserts were specific forC. jejuni.the 1.5 kb DNA insert was partly sequenced, and a 19 base oligomer probe was selected from the sequences. Southern hybridization indicated that the oligomer probe hybridized with DNA from all seven strains ofC. jejunitested bus did not hybridize with DNA from four strains ofC. coli, one strain ofC. fetusandC. laridis, or 11 other bacterial species tes

ISSN:1060-3999    

DOI:10.1111/j.1745-4581.1992.tb00072.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY