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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 -
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 -
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 -
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 -
Molecules (Basel, Switzerland) Dec 2022The main target of this work is to discover new protein fractions from natural resources with high antibacterial action. The 7S and 11S globulin fractions, as well as...
The main target of this work is to discover new protein fractions from natural resources with high antibacterial action. The 7S and 11S globulin fractions, as well as the basic subunit (BS), were isolated from lupine seeds (), chemically characterized, and screened for antibacterial activity against seven pathogenic bacteria. SDS-PAGE revealed molecular weights ranging from 55 to 75 kDa for 7S globulin, 20-37 kD for 11S globulin, and 20 kD for the BS. 11S globulin and the BS migrated faster on Urea-PAGE toward the cathode compared to 7S globulin. FTIR and NMR showed different spectral patterns between the 7S and 11S globulins but similar ones between 11S globulin and the BS. The MICs of the BS were in the range of 0.05-2 μg/mL against , , , , , , and compared to higher values for 11S globulin. The BS surpassed 11S globulin in antibacterial action, while 7S globulin showed no effect. The MICs of 11S globulin and the BS represented only 5% and 2.5% of the specific antibiotic against , respectively. Scanning electron microscopy (SEM) demonstrated different signs of cellular deformation and decay in the protein-treated bacteria, probably due to interaction with the bacterial cell wall and membranes. 11S globulin and the BS can be nominated as effective food biopreservatives.
Topics: Lupinus; Globulins; Vegetables; Anti-Bacterial Agents; Seeds
PubMed: 36615230
DOI: 10.3390/molecules28010035 -
Journal of Advanced Veterinary and... Mar 2022The work aimed to assess the safety and quality of broiler meat in experimental listeriosis changes in storage.
OBJECTIVE
The work aimed to assess the safety and quality of broiler meat in experimental listeriosis changes in storage.
MATERIALS AND METHODS
Ross Cobb 500 chickens (40) were divided into 4 groups of 10 animals each. Chickens from three experimental groups were infected by , , and . Meat samples were stored for 5 days at 0°C-4°C. Meat samples were kept in the refrigerator for 3, 4, and 5 days. Microbiological and laboratory indicators of meat freshness were found on these days as well.
RESULTS
After the slaughter of chickens with experimental listeriosis, pathological changes in muscles and organs were noted against the background of fattening carcasses with a high slaughter yield. By bacterial contamination, 1 day after slaughter, the meat of chickens of the experimental groups (, , and ) outperformed the control group by almost 1.9, 13.9, and 24.7 times, respectively ( < 0.05). The same trend is observed for the third, fourth, and fifth days of meat storage. To keep chicken meat fresh for 5 days, only samples from the control group stayed fresh.
CONCLUSION
According to the total bacterial contamination, the meat of chickens of the groups and was dangerous to human health after 5 and 4 days of storage, respectively. From the first day after the chickens were killed, the meat of chickens that had been infected with did not meet the requirements (up to 100 CFU/gm) and was not safe to store or eat.
PubMed: 35445111
DOI: 10.5455/javar.2022.i580