scholarly journals Characterization of a Novel Group of Listeria Phages That Target Serotype 4b Listeria monocytogenes

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 671
Author(s):  
Yaxiong Song ◽  
Tracey L. Peters ◽  
Daniel W. Bryan ◽  
Lauren K. Hudson ◽  
Thomas G. Denes
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Biocontrol Agent ◽  
Novel Species ◽  
Morphological Characteristics ◽  
Inhibitory Effect ◽  
One Step ◽  
Step Growth ◽  
Serotype 4B

Listeria monocytogenes serotype 4b strains are the most prevalent clinical isolates and are widely found in food processing environments. Bacteriophages are natural viral predators of bacteria and are a promising biocontrol agent for L. monocytogenes. The aims of this study were to characterize phages that specifically infect serotype 4b strains and to assess their ability to inhibit the growth of serotype 4b strains. Out of 120 wild Listeria phages, nine phages were selected based on their strong lytic activity against the model serotype 4b strain F2365. These nine phages can be divided into two groups based on their morphological characteristics and host range. Comparison to previously characterized phage genomes revealed one of these groups qualifies to be defined as a novel species. Phages LP-020, LP-027, and LP-094 were selected as representatives of these two groups of phages for further characterization through one-step growth curve and inhibition of serotype 4b L. monocytogenes experiments. Listeria phages that target serotype 4b showed an inhibitory effect on the growth of F2365 and other serotype 4 strains and may be useful for biocontrol of L.monocytogenes in food processing environments.

scholarly journals Characterization of RNA synthesis during a one-step growth curve and of the replication mechanism of bovine viral diarrhoea virus

1996 ◽  
Vol 77 (11) ◽  
pp. 2729-2736 ◽  
Author(s):  
Y. Gong ◽  
R. Trowbridge ◽  
T. B. Macnaughton ◽  
E. G. Westaway ◽  
A. D. Shannon ◽  
...  
Keyword(s):  
Growth Curve ◽  
Rna Synthesis ◽  
Bovine Viral Diarrhoea Virus ◽  
Bovine Viral Diarrhoea ◽  
Replication Mechanism ◽  
Diarrhoea Virus ◽  
One Step ◽  
Step Growth

scholarly journals Heavy Metal and Disinfectant Resistance of Listeria monocytogenes from Foods and Food Processing Plants

2012 ◽  
Vol 78 (19) ◽  
pp. 6938-6945 ◽  
Author(s):  
Shakir S. Ratani ◽  
Robin M. Siletzky ◽  
Vikrant Dutta ◽  
Suleyman Yildirim ◽  
Jason A. Osborne ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Listeria Monocytogenes ◽  
Food Processing ◽  
Cadmium Resistance ◽  
Content Type ◽  
Ecological History ◽  
Resistance Determinants ◽  
Processing Plants ◽  
History Of ◽  
Serotype 4B

ABSTRACTThe persistence ofListeria monocytogenesin food processing plants and other ecosystems reflects its ability to adapt to numerous stresses. In this study, we investigated 138 isolates from foods and food processing plants for resistance to the quaternary ammonium disinfectant benzalkonium chloride (BC) and to heavy metals (cadmium and arsenic). We also determined the prevalence of distinct cadmium resistance determinants (cadA1,cadA2, andcadA3) among cadmium-resistant isolates. Most BC-resistant isolates were resistant to cadmium as well. Arsenic resistance was encountered primarily in serotype 4b and was an attribute of most isolates of the serotype 4b epidemic clonal group ECIa. Prevalence of the known cadmium resistance determinants was serotype associated:cadA1was more common in isolates of serotypes 1/2a and 1/2b than 4b, whilecadA2was more common in those of serotype 4b. A subset (15/77 [19%]) of the cadmium-resistant isolates lacked the known cadmium resistance determinants. Most of these isolates were of serotype 4b and were also resistant to arsenic, suggesting novel determinants that may confer resistance to both cadmium and arsenic in these serotype 4b strains. The findings may reflect previously unrecognized components of the ecological history of different serotypes and clonal groups ofL. monocytogenes, including exposures to heavy metals and disinfectants.

Formation of Biofilm at Different Nutrient Levels by Various Genotypes of Listeria monocytogenes

2006 ◽  
Vol 69 (4) ◽  
pp. 826-834 ◽  
Author(s):  
JAMES P. FOLSOM ◽  
GREGORY R. SIRAGUSA ◽  
JOSEPH F. FRANK
Keyword(s):  
Listeria Monocytogenes ◽  
Food Processing ◽  
Hoechst 33258 ◽  
Genetic Subtype ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Different Strains ◽  
Element Sequence ◽  
Range Test

Strains of Listeria monocytogenes differ in their ability to form biofilms. The objectives of this study were to determine whether genetically related strains have similar biofilm-forming capacities and what effect nutrient concentration has on the ability of different strains to produce biofilms. Biofilms of 30 strains of L. monocytogenes, obtained from a variety of sources were grown on stainless steel in tryptic soy broth (TSB) or in a 1:10 dilution of TSB (DTSB) for 24 h at 32°C. The amount of biofilm formed was determined with image analysis after cells were stained with bisBenzimide H 33258 (Hoechst 33258). The strains were genetically subtyped by repetitive element sequence–based PCR (rep-PCR) with the primer set rep-PRODt and rep-PROG5. Data were analyzed with an analysis of variance and Duncan's multiple range test. Eleven strains produced the same amount of biofilm in both media. Fourteen strains produced more biofilm in TSB than in DTSB. Five strains produced more biofilm in DTSB than in TSB. Serotype 4b strains produced more biofilm in TSB than did serotype 1/2a strains, whereas serotype 1/2a strains produced more biofilm in DTSB than did serotype 4b strains. Growth in DTSB resulted in decreased biofilm accumulation for serotype 4b strains. There was no correlation between genetic subtype and the amount of biofilm accumulation. These results indicate that strains of serotype 1/2a and serotype 4b differ in the regulation of their biofilm phenotype. The poor biofilm accumulation of serotype 4b isolates when grown in DTSB could be a factor in the predominance of serogroup 1/2 strains in food processing plants, where nutrients may be limited.

Two Step Growth and Characterization of BaF2/Si(III) Heterostructures

1994 ◽  
Vol 356 ◽  
Author(s):  
A. Belenchuk ◽  
A. Fedorov ◽  
V. Lucash ◽  
A. Vasilyev ◽  
V. Zenchenco
Keyword(s):  
Growth Conditions ◽  
Postgrowth Annealing ◽  
Growth Method ◽  
One Step ◽  
Step Growth

AbstractThe influence of growth conditions on structural perfections and epitaxial relation in BaF2 films on Si(111) are considered. It is shown that rotational-twin-free BaF2 films (A-type orientation) can be grown on Si(111) by two step growth method. It is also shown that a mixed (A+B)-type orientation, which usually observed in BaF2 films grown by conventional one step growth method, can be converted into A-type orientation by postgrowth annealing. The correlation between type of epitaxial orientation in BaF2 films and structures of interface is discussed.

scholarly journals CHARACTERIZATION OF T4 MUTANTS THAT PARTIALLY SUPPRESS THE INABILITY OF T4rII TO GROW IN LAMBDA LYSOGENS

Genetics ◽  
1976 ◽  
Vol 83 (3) ◽  
pp. 477-487
Author(s):  
Theodore Homyk ◽  
Angel Rodriguez ◽  
Jon Weil
Keyword(s):  
Burst Size ◽  
Personal Communication ◽  
Growth Cycle ◽  
Plaque Morphology ◽  
One Step ◽  
Step Growth ◽  
The One ◽  
Phage Growth ◽  
L1 And L2

ABSTRACT In the course of isolating viable T4 deletions that affect plaque morphology (Homyk and Weil 1974), two closely linked point mutants, sip1 and sip2, were obtained. They map between genes t and 52, cause a reduction in plaque size and burst size, and partially suppress the lethality of rII mutants for growth in lambda lysogens. These characteristics demonstrate that sip1 and sip2 are similar to mutants previously reported by Freedman and Brenner (1972). In addition, D. Hall (personal communication) has shown that sip1 and sip2 are similar to the mutant farP85, which affects the regulation of a number of early genes (Chace and Hall 1975).—Sip suppression of rII mutants can be demonstrated in one-step growth experiments, even when both rII genes are completely deleted. This indicates that sip mutants do not simply reduce the level of rII gene products required for growth in a lambda lysogen. Instead, they alter the growth cycle so as to partially circumvent the need for any rII products.—Mutations at two other sites, designated L1 and L2, reverse the poor phage growth caused by sip and, in the one case tested, reverse the rII-suppressing ability of sip.

Prevalence and Characteristics of Listeria monocytogenes in Bovine Colostrum in Japan

2013 ◽  
Vol 76 (2) ◽  
pp. 248-255 ◽  
Author(s):  
MEGUMI HASEGAWA ◽  
ERIKO IWABUCHI ◽  
SHIORI YAMAMOTO ◽  
HIDETAKE ESAKI ◽  
KAZUHIKO KOBAYASHI ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Dairy Farms ◽  
Pulsed Field Gel Electrophoresis ◽  
Bovine Colostrum ◽  
Pfge Type ◽  
Type Isolate ◽  
Serotype 1 ◽  
Serotype 4B

This study was conducted to determine the prevalence and characteristics of Listeria monocytogenes in bovine colostrum in Japan. We collected bovine colostrum samples from 210 dams from 21 dairy farms in Hokkaido prefecture (Japan) between March and June 2009. L. monocytogenes was detected in samples from 6 (28.6%) of the 21 farms. Of the 210 samples, 16 (7.6%) were positive for L. monocytogenes. We recovered 80 L. monocytogenes isolates; 44 (55%) isolates were classified as serotype 1/2b and 36 (45%) were classified as serotype 4b. The isolates were susceptible to penicillin, ampicillin, amoxicillin, gentamicin, kanamycin, streptomycin, erythromycin, vancomycin, tetracycline, chloramphenicol, ciprofloxacin, and trimethoprimsulfamethoxazole. Pulsed-field gel electrophoresis (PFGE) characterization of the 80 isolates revealed six PFGE types. Two PFGE types corresponded to human listeriosis cases. Most L. monocytogenes isolates possessed virulence-associated genes (actA, hly, iap, inlA, inlC, mpl, plcA, plcB, opuCA, prfA, and clpC). One PFGE type isolate possessed an epidemic clone II marker. Our findings suggest that isolates from bovine colostrum have the potential to cause human and animal listeriosis. This is the first study on the prevalence and characteristics of L. monocytogenes isolated from bovine colostrum obtained from dairy farms. Our results have important implications for improving public health and elucidating the epidemiology of L. monocytogenes in bovine colostrum.

Characterization of Streptococcus durans bacteriophages

1968 ◽  
Vol 14 (4) ◽  
pp. 397-402 ◽  
Author(s):  
Marvin D. Brailsford ◽  
Paul A. Hartman
Keyword(s):  
Adsorption Kinetics ◽  
Temperature Effects ◽  
Rumen Fluid ◽  
Growth Characteristics ◽  
Plaque Morphology ◽  
Fecal Samples ◽  
Bovine Rumen ◽  
One Step ◽  
Step Growth

Streptococcus durans bacteriophages were isolated from bovine rumen fluid, feed lot soil, bovine fecal samples, and lysogenic strains of S. durans. The presence of different phage strains was suggested by antiserum neutralization tests and one-step growth characteristics, whereby the bacteriophages were placed into three distinct, but serologically related, groups. These phages were further characterized by plaque morphology, phage morphology, adsorption kinetics, and pH and temperature effects.

scholarly journals Heavy-Metal and Benzalkonium Chloride Resistance of Listeria monocytogenes Isolates from the Environment of Turkey-Processing Plants

2008 ◽  
Vol 74 (5) ◽  
pp. 1464-1468 ◽  
Author(s):  
S. Mullapudi ◽  
R. M. Siletzky ◽  
S. Kathariou
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Food Processing ◽  
Benzalkonium Chloride ◽  
The United States ◽  
Limited Information ◽  
Chloride Resistance ◽  
Processing Plants ◽  
Serotype 1 ◽  
Serotype 4B

ABSTRACT The resistance of Listeria monocytogenes to cadmium and arsenic has been used extensively for strain subtyping. However, limited information is available on the prevalence of such resistance among isolates from the environment of food-processing plants. In addition, it is not known whether the resistance of such isolates to heavy metals may correlate with resistance to quaternary ammonium compounds extensively used as disinfectants in the food-processing industry. In this study, we characterized 192 L. monocytogenes isolates (123 putative strains) from the environment of turkey-processing plants in the United States for resistance to cadmium and arsenic and to the quaternary ammonium disinfectant benzalkonium chloride (BC). Resistance to cadmium was significantly more prevalent among strains of serotypes 1/2a (or 3a) and 1/2b (or 3b) (83% and 74%, respectively) than among strains of the serotype 4b complex (19%). Resistance to BC was encountered among 60% and 51% of the serotype 1/2a (or 3a) and 1/2b (or 3b) strains, respectively, and among 7% of the strains of the serotype 4b complex. All BC-resistant strains were also resistant to cadmium, although the reverse was not always the case. In contrast, no correlation was found between BC resistance and resistance to arsenic, which overall was low (6%). Our findings suggest that the processing environment of turkey-processing plants may constitute a reservoir for L. monocytogenes harboring resistance to cadmium and to BC and raise the possibility of common genetic elements or mechanisms mediating resistance to quaternary ammonium disinfectants and to cadmium in L. monocytogenes.

Characterization of Virulence Properties of Listeria monocytogenes Serotype 4b Strains of Different Origins

2008 ◽  
Vol 55 (5) ◽  
pp. 242-248 ◽  
Author(s):  
H. Werbrouck ◽  
N. Botteldoorn ◽  
L. Ceelen ◽  
A. Decostere ◽  
M. Uyttendaele ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Serotype 4B ◽  
Different Origins ◽  
Virulence Properties
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