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Microbiology Spectrum Jul 2018For nearly a century the use of antibiotics to treat infectious diseases has benefited human and animal health. In recent years there has been an increase in the... (Review)
Review
For nearly a century the use of antibiotics to treat infectious diseases has benefited human and animal health. In recent years there has been an increase in the emergence of antibiotic-resistant bacteria, in part attributed to the overuse of compounds in clinical and farming settings. The genus currently comprises 17 recognized species found throughout the environment. is the etiological agent of listeriosis in humans and many vertebrate species, including birds, whereas causes infections mainly in ruminants. is the third-most-common cause of death from food poisoning in humans, and infection occurs in at-risk groups, including pregnant women, newborns, the elderly, and immunocompromised individuals.
Topics: Aged; Animals; Animals, Domestic; Anti-Infective Agents; Drug Resistance, Bacterial; Farms; Female; Food Microbiology; Foodborne Diseases; Humans; Infant, Newborn; Interspersed Repetitive Sequences; Listeria; Listeria monocytogenes; Listeriosis; Pregnancy
PubMed: 30027884
DOI: 10.1128/microbiolspec.ARBA-0031-2017 -
Clinical Microbiology Reviews Jul 2001The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the... (Review)
Review
The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. Clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. Listeriosis can also manifest as a febrile gastroenteritis syndrome. In addition to humans, L. monocytogenes affects many vertebrate species, including birds. Listeria ivanovii, a second pathogenic species of the genus, is specific for ruminants. Our current view of the pathophysiology of listeriosis derives largely from studies with the mouse infection model. Pathogenic listeriae enter the host primarily through the intestine. The liver is thought to be their first target organ after intestinal translocation. In the liver, listeriae actively multiply until the infection is controlled by a cell-mediated immune response. This initial, subclinical step of listeriosis is thought to be common due to the frequent presence of pathogenic L. monocytogenes in food. In normal individuals, the continual exposure to listerial antigens probably contributes to the maintenance of anti-Listeria memory T cells. However, in debilitated and immunocompromised patients, the unrestricted proliferation of listeriae in the liver may result in prolonged low-level bacteremia, leading to invasion of the preferred secondary target organs (the brain and the gravid uterus) and to overt clinical disease. L. monocytogenes and L. ivanovii are facultative intracellular parasites able to survive in macrophages and to invade a variety of normally nonphagocytic cells, such as epithelial cells, hepatocytes, and endothelial cells. In all these cell types, pathogenic listeriae go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. In this way, listeriae disseminate in host tissues sheltered from the humoral arm of the immune system. Over the last 15 years, a number of virulence factors involved in key steps of this intracellular life cycle have been identified. This review describes in detail the molecular determinants of Listeria virulence and their mechanism of action and summarizes the current knowledge on the pathophysiology of listeriosis and the cell biology and host cell responses to Listeria infection. This article provides an updated perspective of the development of our understanding of Listeria pathogenesis from the first molecular genetic analyses of virulence mechanisms reported in 1985 until the start of the genomic era of Listeria research.
Topics: Animals; Bacterial Proteins; Humans; Listeria; Listeriosis; Virulence
PubMed: 11432815
DOI: 10.1128/CMR.14.3.584-640.2001 -
Microorganisms Aug 2022and , are the only pathogenic species of the genus and share many virulence factors and mechanisms of pathogenicity. shows host tropism towards small ruminants and... (Review)
Review
and , are the only pathogenic species of the genus and share many virulence factors and mechanisms of pathogenicity. shows host tropism towards small ruminants and rodents and much lower virulence for humans compared to . However, severe infections caused by , resulting in bacteremia, abortion and stillbirth, occasionally occurred in immunocompromised persons and in pregnant women, while in immunocompetent hosts can cause gastroenteritis. In this review, the updated knowledge on virulence aspects and distribution of in the environment and in food is summarized. Recent research on its virulence characters at genome level gave indications on how pathogenicity evolved in this bacterial species. As for , infections occurred after the ingestion of contaminated food, so an overview of reports regarding its distribution in food products was carried out to obtain indications on the categories of foods exposed to contamination by . It was found that a wide variety of food products can be a source of this microorganism and that, like , is able to persist in the food production environment. Studies on its ability to grow in enrichment and isolation media suggested that its occurrence in nature might be underestimated. Moreover, virulence varies among strains for differences in virulence character regulation, presence/absence of genetic regions and the possible instability of a pathogenicity genomic island, LIPI-2, which is unique to . We can conclude that , as a possible pathogen for animals and humans, requires more focused investigations regarding its occurrence in the environment and in food and on intra-species variability of pathogenic potential.
PubMed: 36014096
DOI: 10.3390/microorganisms10081679 -
PloS One 2017Listeria monocytogenes is a Gram-positive, facultative intracellular and invasive bacterium that has tropism to the placenta, and causes fetal morbidity and mortality in... (Comparative Study)
Comparative Study
Listeria monocytogenes is a Gram-positive, facultative intracellular and invasive bacterium that has tropism to the placenta, and causes fetal morbidity and mortality in several mammalian species. While infection with L. monocytogenes and L. ivanovii are known as important causes of abortion and reproductive failure in cattle, the pathogenesis of maternal-fetal listeriosis in this species is poorly known. This study used the bovine chorioallantoic membrane explant model to investigate the kinetics of L. monocytogenes, L. ivanovii, and L. innocua infections in bovine trophoblastic cells for up to 8 h post infection. L. monocytogenes and L. ivanovii were able to invade and multiply in trophoblastic cells without causing cell death or inducing expression of pro-inflammatory genes. Although L. innocua was unable to multiply in bovine trophoblastic cells, it induced transcription of the pro-inflammatory mediator CXCL6. This study demonstrated for the first time the susceptibility of bovine trophoblastic cells to L. monocytogenes and L. ivanovii infection.
Topics: Animals; Cattle; Cattle Diseases; Female; Listeria; Listeria monocytogenes; Listeriosis; Placenta; Pregnancy; Real-Time Polymerase Chain Reaction; Trophoblasts
PubMed: 28467447
DOI: 10.1371/journal.pone.0176911 -
Frontiers in Veterinary Science 2020subsp. is an intracellular bacterium distributed widely in nature, causing the listeriosis in ruminants and humans. Previous researches had isolated 116 strains of...
subsp. is an intracellular bacterium distributed widely in nature, causing the listeriosis in ruminants and humans. Previous researches had isolated 116 strains of subsp. from wild rodents and pikas of different regions in China, and the predominant sequence types were ST1 and ST2. In this study, we first investigated the biological characteristics and virulence of these two clonal strains including motility, metabolism and virulence in cells and mouse model. The results demonstrated the ST1 strains exhibited motility, wide metabolic activity and hypervirulence, whereas the ST2 strains showed non-motility, relative lower metabolic activity and virulence. Considering the transmissible ability from wild rodents and pikas to ecological environment, the subsp. with potential pathogenicity to humans and ruminants should be monitored.
PubMed: 32161763
DOI: 10.3389/fvets.2020.00088 -
Microbial Genomics Jul 2022() is a bacterial pathogen that causes listeriosis in immunocompromised individuals, particularly pregnant women. Several virulence factors support the intracellular...
() is a bacterial pathogen that causes listeriosis in immunocompromised individuals, particularly pregnant women. Several virulence factors support the intracellular lifecycle of and facilitate cell-to-cell spread, allowing it to occupy multiple niches within the host and cross-protective barriers, including the placenta. One family of virulence factors, internalins, contributes to pathogenicity by inducing specific uptake and conferring tissue tropism. Over 25 internalins have been identified thus far, but only a few have been extensively studied. Internalins contain leucine-rich repeat (LRR) domains that enable protein-protein interactions, allowing to bind host proteins. Notably, other species express internalins but cannot colonize human hosts, prompting questions regarding the evolution of internalins within the genus . Internalin P (InlP) promotes placental colonization through interaction with the host protein afadin. Although prior studies of InlP have begun to elucidate its role in pathogenesis, there remains a lack of information regarding homologs in other species. Here, we have used a computational evolutionary approach to identify InlP homologs in additional species. We found that () and () encode InlP homologs. We also found InlP-like homologs in and the recently identified species . All newly identified homologs lack the full-length LRR6 and LRR7 domains found in 's InlP. These findings are informative regarding the evolution of one key virulence factor, InlP, and serve as a springboard for future evolutionary studies of pathogenesis as well as mechanistic studies of internalins.
Topics: Bacterial Proteins; Female; Humans; Listeria; Listeria monocytogenes; Listeriosis; Placenta; Pregnancy; Virulence Factors
PubMed: 35904424
DOI: 10.1099/mgen.0.000828 -
Frontiers in Microbiology 2016Listeria monocytogenes (LM) vectors have shown much promise in delivery of viral and tumor antigens for the development of vaccines. L. ivanovii (LI) is a closely...
Listeria monocytogenes (LM) vectors have shown much promise in delivery of viral and tumor antigens for the development of vaccines. L. ivanovii (LI) is a closely related bacterium with a similar intracellular life cycle that may offer advantages over LM because it is not a human pathogen, but can infect other animal species. Recent studies show that recombinant LI expressing Mycobacterium tuberculosis antigens is effective in inducing protective immunity in mouse models, demonstrating the potential of LI as a live vaccine vector. However, a key barrier in the development of LI into a live vaccine vector is that its pathogenic and immunogenic characteristics have yet to be fully understood. Therefore, in this research, C57BL/6J mice were inoculated with LM or LI intravenously or intranasally, and bacterial loads, histopathologic changes, and cytokine production were determined at indicated days post inoculation. Results showed that after intravenous infection with LM or LI, bacteria were found proliferating in the liver, spleen, and lung. However, LI could only reach a heavy burden in the liver and its ability to multiply and to resist host immunity seemed limited in the spleen and lung. After intranasal inoculation with LI, bacteria were mainly localized in the lung and failed to infect liver or spleen, while LM could. In organs with heavy LI burden, lesions were isolated, localized and densely packed, compared to lesions caused by LM, which were invasive. In the liver of intravenously inoculated mice and lung of intranasally inoculate mice, LI was able to elicit comparable cytokine production with LM and cause less severe histopathologic damages, and thus could be considered as a vector for treating or preventing hepatic or pulmonary diseases.
PubMed: 27375558
DOI: 10.3389/fmicb.2016.00790 -
Biology Jun 2022A cross-sectional study was performed in 325 sheep and 119 goat dairy farms in Greece. Samples of bulk-tank milk were examined by standard microbiological techniques for...
Isolation of from Bulk-Tank Milk of Sheep and Goat Farms-From Clinical Work to Bioinformatics Studies: Prevalence, Association with Milk Quality, Antibiotic Susceptibility, Predictors, Whole Genome Sequence and Phylogenetic Relationships.
A cross-sectional study was performed in 325 sheep and 119 goat dairy farms in Greece. Samples of bulk-tank milk were examined by standard microbiological techniques for spp. was isolated from one (0.3%) and from three (0.9%) sheep farms. No associations between the isolation of or and milk quality were found. No resistance to antibiotics was identified. Three variables emerged as significant predictors of isolation of the organism: the presence of pigs, low average relative humidity and a high number of ewes on the farm. The three isolates were assessed in silico for identification of plasmids, prophages, antibiotic resistance genes, virulence factors, CRISPRs and CAS genes. Phylogenetic analysis using the core genome revealed that the three strains belonged to the subsp. branch and were especially close to the PAM 55 strain. All strains of the branch appeared to be very similar, with the distance between them being small.
PubMed: 35741392
DOI: 10.3390/biology11060871 -
Journal of Bacteriology Jul 2021Listeria ivanovii () is an intracellular Gram-positive pathogen that primarily infects ruminants but also occasionally causes enteric infections in humans. Albeit rare,...
Listeria ivanovii () is an intracellular Gram-positive pathogen that primarily infects ruminants but also occasionally causes enteric infections in humans. Albeit rare, this bacterium possesses the capacity to cross the intestinal epithelium of humans, similar to its more frequently pathogenic cousin, Listeria monocytogenes (). Recent studies in have shown that specific glycosyl modifications on the cell wall-associated glycopolymers (termed wall teichoic acid [WTA]) of are responsible for bacteriophage adsorption and retention of the major virulence factor internalin B (InlB). However, the relationship between InlB and WTA in remains unclear. Here, we report the identification of the unique gene , which encodes a putative glucosyltransferase in the polycistronic WTA gene cluster of the WSLC 3009 genome. We found that in-frame deletion of led to loss of the glucose substitution on WTA, as revealed by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) analysis. Interestingly, the glucose-deficient mutant became resistant to phage B025 infection due to an inability of the phage to adsorb to the bacterial surface, a binding process mediated by the receptor-binding protein B025_Gp17. As expected, deletion of led to loss of InlB retention on the bacterial cell wall, which corresponded to a drastic decrease in cellular invasion. Genetic complementation of restored the characteristic phenotypes, including glucose decoration, phage adsorption, and cellular invasion. Taken together, our data demonstrate that an interplay between phage, bacteria, and host cells also exists in Listeria ivanovii, suggesting that the trade-off between phage resistance and virulence attenuation may be a general feature in the genus . Listeria ivanovii is a Gram-positive bacterial pathogen known to cause enteric infection in rodents and ruminants and occasionally in immunocompromised humans. Recent investigations revealed that in its better-known cousin Listeria monocytogenes, strains develop resistance to bacteriophage attack due to loss of glycosylated surface receptors, which subsequently results in disconnection of one of the bacterium's major virulence factors, InlB. However, the situation in remains unclear. Here, we show that acquires phage resistance following deletion of a unique glycosyltransferase. This deletion also leads to dysfunction of InlB, making the resulting strain unable to invade host cells. Overall, this study suggests that the interplay between phage, bacteria, and the host may be a feature common to the genus .
Topics: Adsorption; Bacterial Proteins; Bacteriophages; Cell Wall; Glucose; Glycosylation; Host-Pathogen Interactions; Lipopolysaccharides; Listeria; Listeria monocytogenes; Membrane Proteins; Teichoic Acids; Virulence
PubMed: 34096780
DOI: 10.1128/JB.00136-21 -
BioMed Research International 2015The aim of this study was to assess the occurrence of L. ivanovii in foods and food processing environments in Ireland, to track persistence, and to characterize the...
The aim of this study was to assess the occurrence of L. ivanovii in foods and food processing environments in Ireland, to track persistence, and to characterize the disease causing potential of the isolated strains. A total of 2,006 samples (432 food samples and 1,574 environmental swabs) were collected between March 2013 and March 2014 from 48 food business operators (FBOs) belonging to different production sectors (dairy, fish, meat, and fresh-cut vegetable). Six of the forty-eight FBOs had samples positive for L. ivanovii on at least one sampling occasion. L. ivanovii was present in fifteen samples (fourteen environmental samples and one food sample). All but one of those positive samples derived from the dairy sector, where L. ivanovii prevalence was 1.7%. Six distinguishable pulsotypes were obtained by PFGE analysis, with one pulsotype being persistent in the environment of a dairy food business. Sequence analysis of the sigB gene showed that fourteen isolates belonged to L. ivanovii subsp. londoniensis, while only one isolate was L. ivanovii subsp. ivanovii. Cell invasion assays demonstrated that the majority of L. ivanovii strains were comparable to L. monocytogenes EGDe in their ability to invade CACO-2 epithelial cells whilst four isolates had significantly higher invasion efficiencies.
Topics: Animals; Caco-2 Cells; Dairy Products; Electrophoresis, Gel, Pulsed-Field; Environmental Monitoring; Epithelial Cells; Food Contamination; Food Handling; Food Industry; Food Microbiology; Humans; Ireland; Listeria; Listeriosis; Meat; Seafood; Vegetables; Virulence
PubMed: 26543856
DOI: 10.1155/2015/350526