scholarly journals SUSCEPTIBILITY OF Listeria monocytogenes STRAINS ISOLATED FROM FOOD TO ANTIMICROBIAL AGENTS

2008 ◽  
Vol 1 (1) ◽  
pp. 49
Author(s):  
M. Conter ◽  
D. Paludi ◽  
A. Mureddu ◽  
E. Zanardi ◽  
S. Ghidini ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents

scholarly journals Physiological and Transcriptional Characterization of Persistent and Nonpersistent Listeria monocytogenes Isolates

2011 ◽  
Vol 77 (18) ◽  
pp. 6559-6569 ◽  
Author(s):  
Edward M. Fox ◽  
Nola Leonard ◽  
Kieran Jordan
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Cetylpyridinium Chloride ◽  
Phenotype Microarray ◽  
Content Type ◽  
Benzethonium Chloride ◽  
Transcriptomic Sequencing ◽  
Ammonium Compounds ◽  
Compare Gene Expression

ABSTRACTThis study aimed to characterize physiological differences between persistent and presumed nonpersistentListeria monocytogenesstrains isolated at processing facilities and to investigate the molecular basis for this by transcriptomic sequencing. Full metabolic profiles of two strains, one persistent and one nonpersistent, were initially screened using Biolog's Phenotype MicroArray (PM) technology. Based on these results, in which major differences from selected antimicrobial agents were detected, another persistent strain and two nonpersistent strains were characterized using two antimicrobial PMs. Resistance to quaternary ammonium compounds (QACs) was shown to be higher among persistent strains. Growth of persistent and nonpersistent strains in various concentrations of the QACs benzethonium chloride (BZT) and cetylpyridinium chloride (CPC) was determined. Transcriptomic sequencing of a persistent and a presumed nonpersistent strain was performed to compare gene expression among these strains in the presence and absence of BZT. Two strains, designated “frequent persisters” because they were the most frequently isolated at the processing facility, showed overall higher resistance to QACs. Transcriptome analysis showed that BZT induced a complex peptidoglycan (PG) biosynthesis response, which may play a key role in BZT resistance. Comparison of persistent and nonpersistent strains indicated that transcription of many genes was upregulated among persistent strains. This included three gene operons:pdu,cob-cbi, andeut. These genes may play a role in the persistence ofL. monocytogenesoutside the human host.

scholarly journals Activity in vitro of 22 antimicrobial agents against clinical isolates of Listeria monocytogenes

1996 ◽  
Vol 2 (1) ◽  
pp. 63-64 ◽  
Author(s):  
Rosa Blazquez ◽  
Teresa Pelaez ◽  
Patricia Muñoz ◽  
Rosario Sanchez ◽  
Marta Rodriguez-Creixems ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Clinical Isolates

Incidence and Susceptibility to Antimicrobial Agents of Listeria spp. and Listeria monocytogenes Isolated from Poultry Carcasses in Porto, Portugal

2002 ◽  
Vol 65 (12) ◽  
pp. 1888-1893 ◽  
Author(s):  
PATRÍCIA ANTUNES ◽  
CRISTINA RÉU ◽  
JOÃO CARLOS SOUSA ◽  
NAZARÉ PESTANA ◽  
LUÍSA PEIXE
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Polymerase Chain Reaction Method ◽  
Poultry Products ◽  
High Incidence ◽  
Biochemical Identification ◽  
Polymerase Chain ◽  
The City ◽  
Butcher Shops ◽  
Foodborne Infections

The occurrence of Listeria spp. and Listeria monocytogenes in 63 samples of Portuguese poultry carcasses obtained from two local butcher shops and one canteen in the city of Porto, Portugal, and the susceptibility of these bacteria to antimicrobial agents allowed for use in human or animal therapeutics were evaluated. All poultry samples were contaminated with Listeria spp., and L. monocytogenes was isolated from 41% (26 of 63) of the samples. Other Listeria species, including L. innocua, L. welshimeri, and L. seeligeri, were also isolated from poultry samples. A multiplex polymerase chain reaction method was used for the identification of all of the Listeria isolates; this method showed total conformity with the conventional method of biochemical identification and proved to be more reliable, faster, and less arduous. In addition, high percentages of Listeria spp. (84%) and L. monocytogenes (73%) isolates were found to be resistant to one or more antimicrobial agents of different groups, and 12 different resistance profiles were recorded. The frequency of the resistance of L. monocytogenes isolates to enrofloxacin and clindamycin is notable. The results of this study suggest a high incidence of L. monocytogenes on Portuguese poultry products available for consumers and indicate that poultry could be a potential vehicle of foodborne infections due to strains of L. monocytogenes that are resistant to antimicrobial agents.

Influence of Altered Fatty Acid Composition on Resistance of Listeria monocytogenes to Antimicrobials

1993 ◽  
Vol 56 (4) ◽  
pp. 302-305 ◽  
Author(s):  
V. K. JUNEJA ◽  
P. M. DAVIDSON
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Acid Composition ◽  
Lipid Composition ◽  
Antimicrobial Agents ◽  
Food Preservation ◽  
Gas Liquid Chromatography ◽  
Antimicrobial Compounds

The sensitivity of Listeria monocytogenes Scott A and ATCC 19114 to antimicrobial compounds was altered when bacterial membrane lipid composition was modified by growth in the presence of added fatty acids. Analysis of cellular fatty acid composition by gas-liquid chromatography indicated that L. monocytogenes Scott A cells contained 0.97, 2.32, 0.81, and 0.72% (relative) of C14:0, C16:0, C18:0, and C18:l, respectively. In the presence of exogenously supplied C14:0, C16:0, C18:0, and C18:l, the percentages increased to 14.03, 30.92, 16.30, and 27.90%. Average MICs for L. monocytogenes Scott A and ATCC 19114 to sodium chloride, tertiary butylhydroquinone, methyl paraben, and propyl paraben were 10.0%, 81, 1406, and 544 μg/ml, respectively. Growing either strain in the presence of 50 μg/ml of either exogenously added C14:0 or C18:0 fatty acids increased their resistance to the four antimicrobial compounds. However, growth in the presence of C18:1 led to increased sensitivity to the antimicrobial agents. The results indicate that the susceptibility of L. monocytogenes to antimicrobial agents is related to the lipid composition of the cell membrane. Consequently, food preservation processes which alter fatty acid composition of L. monocytogenes could result in changes in antimicrobial susceptibility.

scholarly journals A novel multiresistance gene cluster located on a plasmid-borne transposon in Listeria monocytogenes

2020 ◽  
Vol 75 (4) ◽  
pp. 868-872 ◽  
Author(s):  
He Yan ◽  
Runhao Yu ◽  
Dexi Li ◽  
Lei Shi ◽  
Stefan Schwarz ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gene Cluster ◽  
Antimicrobial Agents ◽  
Natural Transformation ◽  
Integration Site ◽  
Illumina Miseq ◽  
Broth Microdilution ◽  
Antimicrobial Resistance Genes ◽  
Direct Target ◽  
Genetic Context

Abstract Objectives To identify the genetic context and the transferability of the multiresistance gene lsa(E) in Listeria monocytogenes. Methods MICs were determined by broth microdilution. Transferability of lsa(E) was investigated by conjugation, electrotransformation and natural transformation. The lsa(E)-carrying plasmid was sequenced using the Illumina MiSeq and PacBio RSII platforms. The presence of translocatable units (TUs) was examined by PCR. Results The 85 555 bp non-conjugative multiresistance plasmid pNH1 from L. monocytogenes harboured nine antimicrobial resistance genes including a multiresistance gene cluster, consisting of the genes aphA3, erm(B), aadE, spw, lsa(E) and lnu(B), and in addition the genes dfrG, tet(S) and catA8 were also located on plasmid pNH1 The multiresistance gene cluster, and each of the genes tet(S), catA8 and cadA were flanked by IS1216 elements. PCR identified four types of TUs, consisting of either the multiresistance gene cluster and one copy of IS1216, the catA8 gene and one copy of IS1216, or both, but also the tet(S) gene and one copy of IS1216, respectively. Natural transformation into Streptococcus mutans UA159 yielded transformants that harboured a novel 13 208 bp transposon, designated Tn6659. This transposon consisted of the multiresistance gene cluster bounded by IS1216 copies. All transformants displayed elevated MICs of the respective antimicrobial agents. At the integration site in the transformants, 8 bp direct target duplications (5′-ATTCAAAC-3′) were found immediately up- and downstream of Tn6659. Conclusions To the best of our knowledge, this is the first report of this novel multiresistance gene cluster and the gene catA8, flanked by IS1216 elements located on a plasmid of L. monocytogenes. Moreover, a novel functionally active multiresistance transposon was identified.

Antimicrobial Resistance of Listeria monocytogenes Isolated from Various Cabbage Farms and Packing Sheds in Texas

2002 ◽  
Vol 65 (11) ◽  
pp. 1796-1799 ◽  
Author(s):  
ANN MARIE PRAZAK ◽  
ELSA A. MURANO ◽  
IMELDA MERCADO ◽  
GARY R. ACUFF
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Resistance ◽  
Water Samples ◽  
Environmental Samples ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Potential Threat ◽  
Disk Diffusion Method ◽  
Multiresistant Strains ◽  
Multiresistant Strain

Twenty-one isolates of Listeria monocytogenes from cabbage, environmental, and water samples were evaluated for antimicrobial resistance by the disk diffusion method. Ninety-five percent (20 of 21) of the isolates tested were resistant to two or more antimicrobial agents. This finding is significant, since multiresistant strains of Listeria spp. are not commonly found in nature. Eighty-five percent (17 of 20) of the multiresistant strains were resistant to penicillin, and the remaining multiresistant isolates were somewhat sensitive to penicillin. A multiresistant strain showing intermediate sensitivity to penicillin was resistant to gentamicin. One isolate was susceptible to all antimicrobial agents except penicillin. Penicillin- and gentamicin-resistant L. monocytogenes have not previously been reported from human, food, or environmental samples. This study provides evidence of the emergence of multiresistant L. monocytogenes strains, pointing to an increase in the potential threat to human health posed by this pathogen.

scholarly journals Cell Shape and Antibiotic Resistance Are Maintained by the Activity of Multiple FtsW and RodA Enzymes in Listeria monocytogenes

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Jeanine Rismondo ◽  
Sven Halbedel ◽  
Angelika Gründling
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Immune System ◽  
Cell Division ◽  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Protein Complexes ◽  
Inducible Promoter ◽  
Human Pathogen ◽  
Content Type

ABSTRACT Rod-shaped bacteria have two modes of peptidoglycan synthesis: lateral synthesis and synthesis at the cell division site. These two processes are controlled by two macromolecular protein complexes, the elongasome and divisome. Recently, it has been shown that the Bacillus subtilis RodA protein, which forms part of the elongasome, has peptidoglycan glycosyltransferase activity. The cell division-specific RodA homolog FtsW fulfils a similar role at the divisome. The human pathogen Listeria monocytogenes carries genes that encode up to six FtsW/RodA homologs; however, their functions have not yet been investigated. Analysis of deletion and depletion strains led to the identification of the essential cell division-specific FtsW protein, FtsW1. Interestingly, L. monocytogenes carries a gene that encodes a second FtsW protein, FtsW2, which can compensate for the lack of FtsW1, when expressed from an inducible promoter. L. monocytogenes also possesses three RodA homologs, RodA1, RodA2, and RodA3, and their combined absence is lethal. Cells of a rodA1 rodA3 double mutant are shorter and have increased antibiotic and lysozyme sensitivity, probably due to a weakened cell wall. Results from promoter activity assays revealed that expression of rodA3 and ftsW2 is induced in the presence of antibiotics targeting penicillin binding proteins. Consistent with this, a rodA3 mutant was more susceptible to the β-lactam antibiotic cefuroxime. Interestingly, overexpression of RodA3 also led to increased cefuroxime sensitivity. Our study highlights that L. monocytogenes genes encode a multitude of functional FtsW and RodA enzymes to produce its rigid cell wall and that their expression needs to be tightly regulated to maintain growth, cell division, and antibiotic resistance. IMPORTANCE The human pathogen Listeria monocytogenes is usually treated with high doses of β-lactam antibiotics, often combined with gentamicin. However, these antibiotics only act bacteriostatically on L. monocytogenes, and the immune system is needed to clear the infection. Therefore, individuals with a compromised immune system are at risk to develop a severe form of Listeria infection, which can be fatal in up to 30% of cases. The development of new strategies to treat Listeria infections is necessary. Here we show that the expression of some of the FtsW and RodA enzymes of L. monocytogenes is induced by the presence of β-lactam antibiotics, and the combined absence of these enzymes makes bacteria more susceptible to this class of antibiotics. The development of antimicrobial agents that inhibit the activity or production of FtsW and RodA enzymes might therefore help to improve the treatment of Listeria infections and thereby lead to a reduction in mortality.

scholarly journals The LisRK Signal Transduction System Determines the Sensitivity of Listeria monocytogenes to Nisin and Cephalosporins

2002 ◽  
Vol 46 (9) ◽  
pp. 2784-2790 ◽  
Author(s):  
Paul D. Cotter ◽  
Caitriona M. Guinane ◽  
Colin Hill
Keyword(s):  
Signal Transduction ◽  
Listeria Monocytogenes ◽  
Histidine Kinase ◽  
Antimicrobial Agents ◽  
Response Regulator ◽  
Signal Transduction System ◽  
Enhanced Sensitivity ◽  
Virulence Potential ◽  
Two Component Signal Transduction

ABSTRACT The Listeria monocytogenes two-component signal transduction system, LisRK, initially identified in strain LO28, plays a significant role in the virulence potential of this important food-borne pathogen. Here, it is shown that, in addition to its major contribution in responding to ethanol, pH, and hydrogen peroxide stresses, LisRK is involved in the ability of the cell to tolerate important antimicrobials used in food and in medicine, e.g., the lantibiotic nisin and the cephalosporin family of antibiotics. A ΔlisK mutant (lacking the LisK histidine kinase sensor component) displays significantly enhanced resistance to the lantibiotic nisin, a greatly enhanced sensitivity to the cephalosporins, and a large reduction in the expression of three genes thought to encode a penicillin-binding protein, another histidine kinase (other than LisK), and a protein of unknown function. Confirmation of the role of LisRK was obtained when the response regulator, LisR, was overexpressed using both constitutive and inducible (nisin-controlled expression) systems. Under these conditions we observed a reversion of the ΔlisK mutant to wild-type growth kinetics in the presence of nisin. It was also found that overexpression of LisR complemented the reduced expression of two of the aforementioned genes. These results demonstrate the important role of LisRK in the response of L. monocytogenes to a number of antimicrobial agents.

scholarly journals Tolerance of Listeria monocytogenes to Cell Envelope-Acting Antimicrobial Agents Is Dependent on SigB

2006 ◽  
Vol 72 (3) ◽  
pp. 2231-2234 ◽  
Author(s):  
Máire Begley ◽  
Colin Hill ◽  
R. Paul Ross
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Agents ◽  
Cell Envelope ◽  
Treatment Strategies ◽  
Penicillin G ◽  
Lacticin 3147

ABSTRACT Mutation of sigB impairs the ability of Listeria monocytogenes to grow in sublethal levels, and to survive in lethal concentrations, of the bacteriocins nisin and lacticin 3147 and the antibiotics ampicillin and penicillin G. SigB may therefore represent an attractive target for the development of new control and treatment strategies for this important pathogen.

Sign in / Sign up

Export Citation Format

Share Document