RESUMEN

Listeria monocytogenes in beef receives less attention compared to other pathogens such as Salmonella and Escherichia coli. To address this gap, we conducted a literature review focusing on the presence of L. monocytogenes in beef. This review encompasses the pathogenic mechanisms, routes of contamination, prevalence rates, and the laws and regulations employed in various countries. Our findings reveal a prevalence of L. monocytogenes in beef and beef products ranging from 2.5% to 59.4%. Notably, serotype 4b was most frequently isolated in cases of beef contamination during food processing, with the skinning and evisceration stages identified as critical points of contamination.

Asunto(s)

Listeria monocytogenes , Carne Roja , Listeria monocytogenes/aislamiento & purificación , Listeria monocytogenes/genética , Carne Roja/microbiología , Animales , Bovinos , Microbiología de Alimentos , Humanos , Contaminación de Alimentos/análisis , Prevalencia , Listeriosis/microbiología , Listeriosis/epidemiología , Manipulación de Alimentos , Serogrupo

RESUMEN

Human listeriosis is an infectious disease caused by Listeria monocytogenes. The invasive form of this disease leads to a high rate of hospitalizations and fatality. The main mode of transmission is through contaminated ready-to-eat foods such as dairy, vegetables and meat products. The knowledge of the diversity and population dynamics of isolates collected from human and food sources is essential for the detection of clusters and the identification of common sites of infection. The aim of this study was the molecular characterization of L. monocytogenes isolates in Argentina. We sequenced a total of 63 isolates, 35 from human and 28 from food sources, collected between 2018 and 2023. Our genomic study divided the isolates into two lineages, four serogroups, 17 sequence types and 15 clonal complexes (CCs). The hypervirulent clone CC1 (lineage I; serogroup IVb) predominated in human and food samples. The phylogenomic analysis showed a high and possible epidemiological relationship between isolates from human and/or food sources, suggesting the presence of transmission chains in our country. These findings highlight the need to strengthen genomic surveillance of L. monocytogenes in Argentina. The identification of geographic distribution and characteristics of predominant and emerging clones from human and food sources might help to focus action plans and public health policies better directed at the control and prevention of listeriosis.

Asunto(s)

Microbiología de Alimentos , Listeria monocytogenes , Listeriosis , Humanos , Argentina/epidemiología , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Listeria monocytogenes/clasificación , Listeriosis/microbiología , Listeriosis/epidemiología , Filogenia

RESUMEN

The intracellular pathogen Listeria monocytogenes is one of the leading causes of death from foodborne illness in the United States. Internalin A is the key surface protein that drives Listeria uptake by epithelial cells expressing E-cadherin. G. C. Gyanwali, T. U. B. Herath, A. Gianfelice, and K. Ireton (Infect Immun 90:e00326-22, 2022, https://doi.org/10.1128/iai.00326-22) unravel the close relationship between internalin A and the exocyst, adding another layer of complexity to the bacterial internalization process.

Asunto(s)

Enfermedades Transmitidas por los Alimentos , Listeria monocytogenes , Listeriosis , Humanos , Listeria monocytogenes/metabolismo , Internalización del Virus , Proteínas Bacterianas/metabolismo , Proteínas de la Membrana/metabolismo , Listeriosis/microbiología

RESUMEN

Listeriosis is a foodborne disease caused by the Gram-positive bacterium Listeria monocytogenes, a pathogen that modulates its intracellular survival via vacuolar escape and cytosolic replication. In the present study, we examined the ability of 58 L. monocytogenes isolates recovered in Brazil (beef, clinical and environmental samples, from 1978 to 2013) to invade, replicate and spread in a human intestinal epithelial cell line (Caco-2). Premature stop codons were common in the inlA gene of serotype 1/2c strains from beef and environment samples, associated with decreased Caco-2 cell invasion when compared to other serotypes. The isolates varied widely in their intracellular doubling times, and there was no clear relationship between serotypes and samples origin. Serotype 1/2a isolates were generally impaired in their ability to spread between Caco-2 cells, with an average 30 % smaller focus area than the 10403S reference strain. However, most isolates of serotype 1/2b exhibited enhanced cell-to-cell spread, with an average 35 % increase in focus area. Our findings are consistent with serotype being a better predictors of cell invasion potential and cell spread compared with sample origin of isolates, although the most invasive isolates were primarily isolated from beef. Additionally, we have identified isolates that could provide novel insight into the pathogenicity of L. monocytogenes that may not be revealed by studying common laboratory reference strains.

Asunto(s)

Listeria monocytogenes , Listeriosis , Animales , Proteínas Bacterianas/genética , Células CACO-2 , Bovinos , Codón sin Sentido , Microbiología de Alimentos , Humanos , Listeriosis/microbiología , Serogrupo

RESUMEN

Listeria monocytogenes is responsible for causing listeriosis, a type of food poisoning with high mortality. This bacterium is mainly transmitted to humans through the consumption of contaminated foods. Detection of L. monocytogenes through molecular methods is crucial for food safety and clinical diagnosis. Present techniques are characterized by low discrimination power and high cost, as well as being time-consuming and taking several days to give the final result. In our study, MLVA-HRM (Multiple-Locus Variable-number tandem repeats Analysis ‒ High-Resolution Melting) was investigated as an alternative method for a fast and precise method for the genotyping of L. monocytogenes isolates. Forty-eight isolates of L. monocytogenes obtained from the microbial bank of Department of Microbiology, Iran University of Medical Sciences, were typed by MLVA-HRM analysis using five Variable Numbers of Tandem Repeat (VNTR) loci. A total of 43 different types were obtained. This research demonstrated the usefulness of the MLVA-HRMA method and its ability to discriminate L. monocytogenes isolates. Since this method is easier and more efficient than existing methods, it can be widely used in food processing plants and diagnostic laboratories as a fast and accurate method.

Asunto(s)

Listeria monocytogenes , Listeriosis , Microbiología de Alimentos , Genotipo , Humanos , Listeria monocytogenes/genética , Listeriosis/microbiología , Repeticiones de Minisatélite/genética , Secuencias Repetidas en Tándem/genética

RESUMEN

Listeriosis is one of the most common nervous diseases in ruminants, and is caused almost exclusively by the Gram-positive bacterium, Listeria monocytogenes. However, there are few reports of listeriosis associated with L. innocua, which is genetically closely related to L. monocytogenes, but considered non-pathogenic. In this work, we report two cases of suppurative meningoencephalitis in apparently previously healthy ruminants from different farms, in which two strains of L. innocua were recovered. The whole genomes from both isolates were sequenced, allowing phylogenetic analyses to be performed, which indicated that the two strains were very closely related. Virulence determinants were searched, especially genes coding for the main L. monocytogenes virulence factors which have been previously described in L. innocua. Surprisingly, the two isolates do not possess such virulence determinants. Instead, both strains carried a set of genes that encode for other virulence factors of the genus Listeria detected  using the Virulence Factor Database (VFDB): iap (division and invasion of host cells), lpeA (entry into non-professional phagocytes cells), fbpA (multifunctional virulence factor, including adherence to host cells), lspA (surface protein anchoring), lap (adhesion to enterocytes and trans epithelial translocation), pdgA (resistance to lysozyme), oatA (resistance to different antimicrobial compounds and also required for growth inside macrophages), lplA1 (use of host-metabolites for in vivo growth), gtcA (catalyses teichoic acid of bacterial wall), prsA2 (cell invasion, vacuole lysis and intracellular growth), clpC, clpE and clpP (survival under several stress conditions). These genes among others detected, could be involved in the ability of L. innocua to produce damage in animal and human hosts. These results highlight the multifactorial profile of Listeria pathogenesis and the need for comprehensive scientific research that address microbiological, environmental and veterinary aspects of listeriosis.

Asunto(s)

Listeria , Listeriosis , Animales , Listeria/genética , Listeriosis/microbiología , Listeriosis/veterinaria , Filogenia , Rumiantes , Virulencia/genética , Factores de Virulencia/genética

RESUMEN

BACKGROUND: Immunomodulatory therapies are claimed to enhance antimicrobial immunity and counterbalance antimicrobial resistance mechanisms of pathogenic bacteria. PURPOSE: To investigate whether caffeine can be useful for control of inflammation derived from experimental systemic infection with Listeria monocytogenes. METHODS: Peritoneal macrophages (pMØ) from Swiss mice were cultured with caffeine in 96-well plates, and then infected with virulent L. monocytogenes 619. In another experiment, the pMØ were first infected with the bacterium and then treated with caffeine. Swiss mice were inoculated intraperitoneally with L. monocytogenes and then treated intravenously with caffeine (0.05; 0.5 or 5 mg/Kg). RESULTS: Caffeine did not exert direct antibacterial activity in vitro against L. monocytogenes. Macrophages exposed to caffeine before or after infection with L. monocytogenes had increased cell viability, although the intracellular bacterial loads were similar to the control groups. Caffeine treatments of Swiss mice reduced leukocyte infiltration into the peritoneal cavity after L. monocytogenes infection. However, the bacterial burden was reduced in the spleen and liver. The mRNA expressions of IL-1ß, IL-6 and the enzyme inducible nitric oxide synthase (iNOS) were reduced whereas IL-10 was increased. CONCLUSION: Caffeine has an anti-infectious potential and ameliorated infection-derived inflammation following experimental infection with L. monocytogenes.

Asunto(s)

Antiinflamatorios/farmacología , Cafeína/farmacología , Inflamación/tratamiento farmacológico , Listeria monocytogenes/patogenicidad , Listeriosis/tratamiento farmacológico , Macrófagos Peritoneales/efectos de los fármacos , Animales , Cafeína/análogos & derivados , Células Cultivadas , Quimiotaxis de Leucocito/efectos de los fármacos , Modelos Animales de Enfermedad , Interacciones Huésped-Patógeno , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/microbiología , Mediadores de Inflamación/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Listeriosis/metabolismo , Listeriosis/microbiología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/microbiología , Ratones , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Virulencia

RESUMEN

Listeria monocytogenes is an invasive opportunistic foodborne pathogen and its routine surveillance is critical for protecting the food supply and public health. The traditional detection methods are time-consuming and require trained personnel. Lateral flow immunoassay (LFIA), on the other hand, is an easy-to-perform, rapid point-of-care test and has been widely used as an inexpensive surveillance tool. In recent times, nucleic acid-based lateral flow immunoassays (NALFIA) are also developed to improve sensitivity and specificity. A significant improvement in lateral flow-based assays has been reported in recent years, especially the ligands (antibodies, nucleic acids, aptamers, bacteriophage), labeling molecules, and overall assay configurations to improve detection sensitivity, specificity, and automated interpretation of results. In most commercial applications, LFIA has been used with enriched food/environmental samples to ensure detection of live cells thus prolonging the assay time to 24-48 h; however, with the recent improvement in LFIA sensitivity, results can be obtained in less than 8 h with shortened and improved enrichment practices. Incorporation of surface-enhanced Raman spectroscopy and/or immunomagnetic separation could significantly improve LFIA sensitivity for near-real-time point-of-care detection of L. monocytogenes for food safety and public health applications.

Asunto(s)

Inmunoensayo/métodos , Listeria monocytogenes/aislamiento & purificación , Listeriosis/microbiología , Animales , Anticuerpos Inmovilizados/química , Microbiología de Alimentos , Humanos , Inmunoensayo/instrumentación , Listeriosis/diagnóstico , Ácidos Nucleicos/química , Sistemas de Atención de Punto

RESUMEN

Listeria monocytogenes is one of the most invasive foodborne pathogens and is responsible for numerous outbreaks worldwide. Most of the methods to detect this bacterium in food require selective enrichment using traditional bacterial culture techniques that can be time-consuming and labour-intensive. Moreover, molecular methods are expensive and need specific technical knowledge. In contrast, immunological approaches are faster, simpler, and user-friendly alternatives and have been developed for the detection of L. monocytogenes in food, environmental, and clinical samples. These techniques are dependent on the constitutive expression of L. monocytogenes antigens and the specificity of the antibodies used. Here, updated knowledge on pathogenesis and the key immunogenic virulence determinants of L. monocytogenes that are used for the generation of monoclonal and polyclonal antibodies for the serological assay development are summarised. In addition, immunological approaches based on enzyme-linked immunosorbent assay, immunofluorescence, lateral flow immunochromatographic assays, and immunosensors with relevant improvements are highlighted. Though the sensitivity and specificity of the assays were improved significantly, methods still face many challenges that require further validation before use.

Asunto(s)

Listeria monocytogenes/aislamiento & purificación , Listeria monocytogenes/patogenicidad , Listeriosis/microbiología , Factores de Virulencia/análisis , Factores de Virulencia/inmunología , Animales , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/análisis , Antígenos Bacterianos/inmunología , Técnicas Biosensibles , Microbiología de Alimentos , Humanos , Inmunidad Innata , Listeria monocytogenes/crecimiento & desarrollo , Listeria monocytogenes/inmunología , Listeriosis/diagnóstico , Listeriosis/inmunología , Virulencia , Factores de Virulencia/metabolismo

RESUMEN

Primary aortitis (PA) secondary to Listeria monocytogenes is extremely rare with only a few cases reported in the literature. Presently, there is no consensus concerning the best treatment when no complications are found in the thoracic computed tomography (CT) imaging. This report illustrates the clinical presentation and favorable clinical course of a rare case of PA secondary to Listeria monocytogenes in an 82-year-old diabetic woman, successfully treated with conservative management with 18 months of follow up. Included in this article, we additionally present a review of the literature of this uncommon etiology of infectious aortitis.

Asunto(s)

Antibacterianos/uso terapéutico , Aortitis/tratamiento farmacológico , Tratamiento Conservador , Listeria monocytogenes/aislamiento & purificación , Listeriosis/tratamiento farmacológico , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Aortitis/diagnóstico , Aortitis/microbiología , Femenino , Humanos , Listeriosis/diagnóstico , Listeriosis/microbiología , Resultado del Tratamiento

RESUMEN

The human placenta is a dynamic organ that modulates physiological adaptations to pregnancy. To define the immunological signature of the human placenta, we performed unbiased profiling of secreted immune factors from human chorionic villi isolated from placentas at mid and late stages of pregnancy. We show that placental trophoblasts constitutively secrete the inflammasome-associated cytokines IL-1ß and IL-18, which is blocked by NLRP3 inflammasome inhibitors and occurs without detectable gasdermin D cleavage. We further show that placenta-derived IL-1ß primes monocytes for inflammasome induction to protect against Listeria monocytogenes infection. Last, we show that the human placenta responds to L. monocytogenes infection through additional inflammasome activation and that inhibition of this pathway sensitizes villi to infection. Our results thus identify the inflammasome as an important mechanism by which the human placenta regulates systemic and local immunity during pregnancy to defend against L. monocytogenes infection.

Asunto(s)

Vellosidades Coriónicas/inmunología , Inflamasomas/inmunología , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Transducción de Señal/inmunología , Trofoblastos/inmunología , Células CACO-2 , Vellosidades Coriónicas/microbiología , Vellosidades Coriónicas/patología , Femenino , Humanos , Interleucina-18/inmunología , Interleucina-1beta/inmunología , Listeriosis/microbiología , Listeriosis/patología , Monocitos/inmunología , Monocitos/microbiología , Monocitos/patología , Células THP-1 , Trofoblastos/microbiología , Trofoblastos/patología

RESUMEN

Listeria monocytogenes is an opportunistic pathogen with the ability to adapt to different environmental conditions, resulting in safety issues for food producers. Foods contaminated by L. monocytogenes can represent a risk if consumed by susceptible individuals such as elderly, pregnant women and the immunocompromised. The aim of this study was to evaluate the genetic diversity of a collection of L. monocytogenes isolated from different matrices in Brazil during the period of 1979-2015. A total of 51 L. monocytogenes serotype 1/2a strains isolated from clinical samples (n = 3) and food samples (n = 48) were characterized by Multi-Virulence-Locus Sequence Typing (MVLST). The strains were assigned to nine virulence types (VT): VT-11 (n = 3, 5·9%), VT-45 (n = 27, 52·9%), VT-59 (n = 11, 21·6%), VT-68 (n = 3, 5·9%), VT-94 (n = 2, 3·9%), VT-107 (n = 2, 3·9%), VT-184 (n = 1, 1·9%), VT-185 (n = 1, 1·9%) and VT-186 (n = 1, 1·9%); and four of them (VT-11, VT-45, VT-59 and VT-68) have already been associated with cases of listeriosis worldwide. The VT-11, VT-59 (Epidemic Clone V) and VT-186 were identified in blood culture samples, as well as in different classes of foods. It is recommended that the epidemiological surveillance agencies evaluate the risk that foods contaminated with L. monocytogenes VTs pose to susceptible populations.

Asunto(s)

Adaptación Fisiológica/genética , Variación Genética/genética , Listeria monocytogenes/genética , Listeriosis/epidemiología , Factores de Virulencia/genética , Anciano , Brasil/epidemiología , Femenino , Microbiología de Alimentos , Humanos , Listeria monocytogenes/patogenicidad , Listeriosis/microbiología , Tipificación de Secuencias Multilocus , Embarazo , Serogrupo , Virulencia/genética

RESUMEN

Listeria monocytogenes harbor different virulence factors, with a highly heterogeneous distribution between distinct lineages and serotypes. The Listeria Pathogenicity Island 3 (LIPI-3), mainly described in lineage I, encodes for Listeriolysin S (LLS), a virulence factor expressed by L. monocytogenes in the gastrointestinal tract during in vivo infections. The aim of this study was to carry out a comparative genotypic analysis of LIPI-3 identified in L. monocytogenes isolates obtained in Brazil and subjected to whole genomic sequencing (WGS). In addition, transcription of llsX expression under different acid stress conditions was evaluated by RT-PCR. Homologues of the eight LIPI-3 genes (llsAGHXBYDP) were identified in 15 isolates (all from lineage I) representative of different sequence types: ST1 (n = 3), ST3 (n = 6), ST218 (n = 5) and ST288 (n = 1). Single nucleotide polymorphism (SNP) analysis revealed that genetic variation resulted in modification of the final peptide LLS for ST218 (serogroup IVb-v1) and ST288 (serogroup IIb). Selected strains from ST3 and ST288 were subjected to acid stress conditions and the expression of llsX, a LIPI-3 gene, was observed: only F2365 (4b/ST1) presented llsX expression after six hours of acid stress, indicating relevant differences when compared to isolates IIb (ST3 and 288). The results highlight the presence of genomic variations on LIPI-3 and llsX expression under acid stress conditions, demanding further studies to evaluate if these mutations have an impact on L. monocytogenes virulence in vivo.

Asunto(s)

Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Estrés Psicológico , Factores de Virulencia/genética , Microbiología de Alimentos , Inocuidad de los Alimentos , Variación Genética , Islas Genómicas/genética , Genotipo , Proteínas Hemolisinas/genética , Listeriosis/microbiología , Polimorfismo de Nucleótido Simple , Virulencia/genética

RESUMEN

BACKGROUND: Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a disease that can present as febrile gastroenteritis or as an invasive form that has high mortality rates. So far, the genetic diversity of strains of L. monocytogenes isolated from patients, foods and environmental sources in Chile has been poorly studied. AIM: To characterize genetically L. monocytogenes strains received by the Institute of Public Health of Chile (ISP) between 2007 and 2014. METHODS: We selected 94 strains of L. monocytogenes corresponding to 94 different pulsotypes identified by pulsed field gel electrophoresis (PFGE), DNA was extracted and serotyping was performed by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). RESULTS: The most common serotype was 4b (55.3%), followed by serotypes 1/2a (25.5%), 1/2b (17%) and 1/2c (2.2%). 32 sequence-type (ST) were identified, of which 4 were new, and the predominant ones were ST1 (28.7%) and ST2 (13.8%). All the strains of L. monocytogenes were grouped in Lineages I and II. CONCLUSIONS: A great genetic variability was observed in the strains of L. monocytogenes analyzed, being predominant the ST1 and ST2, both belonging to Lineage I. Our results contribute to know the population structure of this pathogen in Chile and its presence in clinical samples, food and the environment.

Asunto(s)

Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Chile , Electroforesis en Gel de Campo Pulsado , Microbiología Ambiental , Microbiología de Alimentos , Variación Genética , Humanos , Listeriosis/microbiología , Tipificación de Secuencias Multilocus , Reacción en Cadena de la Polimerasa , Serotipificación , Factores de Tiempo

RESUMEN

Resumen Introducción: Listeria monocytogenes es un patógeno transmitido por alimentos que causa listeriosis, una enfermedad que puede presentarse como gastroenteritis febril o en una forma invasora que tiene altas tasas de mortalidad. Hasta el momento, ha sido poco estudiada la diversidad genética de cepas de L. monocytogenes aisladas desde pacientes, alimentos y fuentes ambientales en Chile. Objetivo: Caracterizar genéticamente cepas de L. monocytogenes de estos tres orígenes recibidas por el Instituto de Salud Pública de Chile (ISP) entre los años 2007 y 2014. Material y Métodos: Se seleccionaron 94 cepas de L. monocytogenes correspondientes a 94 pulsotipos diferentes identificados por electroforesis en gel de campo pulsado (PFGE), se extrajo ADN y se realizó serotipificación mediante reacción de polimerasa en cadena (RPC) y tipificación de secuencias multilocus (MLST). Resultados: El serotipo más común fue 4b (55,3%), seguido de 1/2a (25,5%), 1/2b (17%) y 1/2c (2,2%). Se identificaron 32 secuencias tipo (ST), de las cuales cuatro fueron nuevas, y las predominantes fueron ST1 (28,7%) y ST2 (13,8%). La totalidad de las cepas se agrupó en los Linajes I y II. Conclusiones: Se observó una gran variabilidad genética en las cepas de L. monocytogenes analizadas, siendo predominantes las secuencias tipo ST1 y ST2, ambas pertenecientes al Linaje I. Nuestros resultados contribuyen a conocer la estructura poblacional de este patógeno en Chile y su presencia en muestras clínicas, alimentos y el medio ambiente.

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Background: Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a disease that can present as febrile gastroenteritis or as an invasive form that has high mortality rates. So far, the genetic diversity of strains of L. monocytogenes isolated from patients, foods and environmental sources in Chile has been poorly studied. Aim: To characterize genetically L. monocytogenes strains received by the Institute of Public Health of Chile (ISP) between 2007 and 2014. Methods: We selected 94 strains of L. monocytogenes corresponding to 94 different pulsotypes identified by pulsed field gel electrophoresis (PFGE), DNA was extracted and serotyping was performed by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). Results: The most common serotype was 4b (55.3%), followed by serotypes 1/2a (25.5%), 1/2b (17%) and 1/2c (2.2%). 32 sequence-type (ST) were identified, of which 4 were new, and the predominant ones were ST1 (28.7%) and ST2 (13.8%). All the strains of L. monocytogenes were grouped in Lineages I and II. Conclusions: A great genetic variability was observed in the strains of L. monocytogenes analyzed, being predominant the ST1 and ST2, both belonging to Lineage I. Our results contribute to know the population structure of this pathogen in Chile and its presence in clinical samples, food and the environment.

Asunto(s)

Humanos , Listeria monocytogenes/aislamiento & purificación , Listeria monocytogenes/genética , Factores de Tiempo , Variación Genética , Serotipificación , Chile , Reacción en Cadena de la Polimerasa , Electroforesis en Gel de Campo Pulsado , Microbiología Ambiental , Tipificación de Secuencias Multilocus , Microbiología de Alimentos , Listeriosis/microbiología

RESUMEN

Listeria monocytogenes is one of the most important foodborne pathogens and is a causal agent of listeriosis in humans and animals. The aim of this study was to determine the prevalence, serogroups, antibiotic susceptibility, virulence factor genes, and genetic relatedness of L. monocytogenes strains isolated from 500 poultry samples in Turkey. The isolation sources of 103 L. monocytogenes strains were retail markets (n = 100) and slaughterhouses (n = 3). L. monocytogenes strains were identified as serogroups 1/2a-3a (75.7%, lineage I), 1/2c-3c (14.56%, lineage I), 1/2b-3b-7 (5.82%, lineage II), 4a-4c (2.91%, lineage III), and 4b-4d-4e (0.97%, lineage III). Most of the L. monocytogenes strains (93.2%) were susceptible to the antibiotics tested. PCR analysis indicated that the majority of the strains (95% to 100%) contained most of the virulence genes (hylA, plcA, plcB, prfA, mpl, actA, dltA, fri, flaA inlA, inlC, and inlJ). Pulsed-field gel electrophoresis (PFGE) demonstrated that there were 18 pulsotypes grouped at a similarity of > 90% among the strains. These results indicate that it is necessary to prevent the presence of L. monocytogenes in the poultry-processing environments to help prevent outbreaks of listeriosis and protect public health.

Asunto(s)

Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Listeriosis/veterinaria , Enfermedades de las Aves de Corral/microbiología , Mataderos/economía , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pollos , Microbiología de Alimentos , Listeria monocytogenes/clasificación , Listeria monocytogenes/efectos de los fármacos , Listeriosis/epidemiología , Listeriosis/microbiología , Enfermedades de las Aves de Corral/economía , Enfermedades de las Aves de Corral/epidemiología , Prevalencia , Turquía/epidemiología , Factores de Virulencia/genética , Factores de Virulencia/metabolismo

RESUMEN

Listeria is an unusual pathogen that causes neonatal infection with high morbidity and mortality. We present the case of a premature newborn whose mother had a rash during pregnancy; the newborn had severe early sepsis because of Listeria monocytogenes and histopathologically suggestive findings of the placenta. Obstetricians and neonatologists should suspect listeriosis in cases with compatible epidemiological history, clinical features, and examination findings of the placenta.

Asunto(s)

Enfermedades del Recién Nacido/diagnóstico , Listeria monocytogenes/aislamiento & purificación , Listeriosis/microbiología , Sepsis/microbiología , Adulto , Femenino , Humanos , Recién Nacido , Enfermedades del Recién Nacido/microbiología , Transmisión Vertical de Enfermedad Infecciosa , Unidades de Cuidado Intensivo Neonatal , Listeriosis/diagnóstico , Listeriosis/transmisión , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo , Sepsis/diagnóstico , Adulto Joven

RESUMEN

Bacterial infections require special care since the indiscriminate use of antibiotics to treat them has been linked to the emergence of resistant strains. In this sense, phytoterapeutic alternatives such as curcumin and its nanocapsules have emerged as a promising supplement in optimizing availability of bioactives and reducing the development of antimicrobial resistance. Thus, the aim of this study was to verify the effects of pure and nanoencapsulated curcumin in the treatment of experimental listeriosis in gerbils regarding many aspects including antibacterial effect, antioxidant mechanisms involved and the energetic metabolism. Four groups were used containing 6 animals each: T0 (control), T1 (infected), T2 (infected and treated with free curcumin - dose of 30 mg/kg/day) and T3 (infected and treated with nanocapsules containing curcumin - a dose of 3 mg/kg/day). Treated animals received curcumin for 6 consecutive days starting 24 h after Listeria monocytogenes infection. All animals were euthanized on the 12th day after L. monocytogenes infection. Quantitative polymerase chain reaction (qPCR) identified L. monocytogenes DNA in the spleens of all animals of the T1 group, as well as T2 (2 out of 6) and T3 (5 out of 6). The weight of the spleens confirmed the infection, since it was larger in the T1 group, differing statistically from T0, and similarly to T2 and T3. Hepatic histopathological examination showed mild infiltration of neutrophils and macrophages, except for the T3 group (only 1/6). In the liver, the pyruvate kinase activity was higher in T1 and T2 compared to T0 and T3. The adenylate kinase activity did not differ between groups. The Na+/K+ATPase activity was lower in T1 group compared to T0 and T3. Lipoperoxidation was lower in the T3 group compared to groups T0, T1 and T2. The antioxidant capacity against peroxyl radicals was higher in T1, T2 and T3 groups compared to T0. In conclusion, free curcumin showed potent antibacterial effects; however, the nanoencapsulated form was able to minimize the effects caused by L. monocytogenes regarding tissue injury, changes on enzymes of the energetic metabolism, in addition to an antioxidant effect against lipoperoxidation.

Asunto(s)

Curcumina/administración & dosificación , Curcumina/uso terapéutico , Listeria monocytogenes/efectos de los fármacos , Listeriosis/tratamiento farmacológico , Listeriosis/veterinaria , Nanocápsulas/química , Adenosina Trifosfatasas , Adenilato Quinasa/efectos de los fármacos , Animales , Antibacterianos/administración & dosificación , Antibacterianos/química , Antibacterianos/uso terapéutico , Antioxidantes/farmacología , Curcumina/química , Suplementos Dietéticos , Modelos Animales de Enfermedad , Gerbillinae , Homeostasis/efectos de los fármacos , Inflamación , Peroxidación de Lípido/efectos de los fármacos , Listeriosis/microbiología , Hígado/patología , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/farmacología , Ácidos Polimetacrílicos/uso terapéutico , Piruvato Quinasa/efectos de los fármacos , ATPasa Intercambiadora de Sodio-Potasio/efectos de los fármacos , Bazo/patología

RESUMEN

Advances in whole-genome sequencing (WGS) technologies have documented genetic diversity and epidemiology of the major foodborne pathogen Listeria monocytogenes (Lm) in Europe and North America, but data concerning South America are scarce. Here, we examined the population structure and genetic diversity of this major foodborne pathogen collected in Brazil. Based on core genome multilocus sequence typing (cgMLST), isolates from lineages I (n = 22; 63%) and II (n = 13; 37%) were distributed into 10 different sublineages (SLs) and represented 31 new cgMLST types (CTs). The most prevalent SLs were SL9 (n = 9; 26%), SL3 (n = 6; 17%) and SL2 and SL218 (n = 5; 14%). Isolates belonging to CTs L2-SL9-ST9-CT4420 and L1-SL315-ST520-CT4429 were collected 3 and 9 years apart, respectively, revealing long-term persistence of Lm in Brazil. Genetic elements associated with stress survival were present in 60% of isolates (57% SSI-1 and 3% SSI-2). Pathogenic islands were present in 100% (LIPI-1), 43% (LIPI-3) and 6% (LIPI-4) of the isolates. Mutations leading to premature stop codons were detected in the prfA and inlA virulence genes. This study is an important contribution to understanding the genomic diversity and epidemiology of Lm in South America. In addition, the results highlight the importance of using WGS to reveal Lm long-term persistence.

Asunto(s)

Listeria monocytogenes/genética , Listeriosis/microbiología , Brasil/epidemiología , Microbiología de Alimentos , Variación Genética , Genoma Bacteriano , Humanos , Listeriosis/epidemiología , Carne/microbiología , Tipificación de Secuencias Multilocus , Virulencia/genética , Secuenciación Completa del Genoma

RESUMEN

Abstract Listeria is an unusual pathogen that causes neonatal infection with high morbidity and mortality. We present the case of a premature newborn whose mother had a rash during pregnancy; the newborn had severe early sepsis because of Listeria monocytogenes and histopathologically suggestive findings of the placenta. Obstetricians and neonatologists should suspect listeriosis in cases with compatible epidemiological history, clinical features, and examination findings of the placenta.

Asunto(s)

Humanos , Masculino , Femenino , Embarazo , Recién Nacido , Adulto , Adulto Joven , Sepsis/microbiología , Enfermedades del Recién Nacido/diagnóstico , Listeriosis/microbiología , Listeria monocytogenes/aislamiento & purificación , Complicaciones Infecciosas del Embarazo , Unidades de Cuidado Intensivo Neonatal , Sepsis/diagnóstico , Transmisión Vertical de Enfermedad Infecciosa , Enfermedades del Recién Nacido/microbiología , Listeriosis/diagnóstico , Listeriosis/transmisión