RESUMO
Dendritic cells (DCs) patrol tissues and transport antigens to lymph nodes to initiate adaptive immune responses. Within tissues, DCs constitute a complex cell population composed of distinct subsets that can exhibit different activation states and functions. How tissue-specific cues orchestrate DC diversification remains elusive. Here, we show that the small intestine included two pools of cDC2s originating from common pre-DC precursors: (1) lamina propria (LP) CD103+CD11b+ cDC2s that were mature-like proinflammatory cells and (2) intraepithelial cDC2s that exhibited an immature-like phenotype as well as tolerogenic properties. These phenotypes resulted from the action of food-derived retinoic acid (ATRA), which enhanced actomyosin contractility and promoted LP cDC2 transmigration into the epithelium. There, cDC2s were imprinted by environmental cues, including ATRA itself and the mucus component Muc2. Hence, by reaching distinct subtissular niches, DCs can exist as immature and mature cells within the same tissue, revealing an additional mechanism of DC functional diversification.
Assuntos
Células Dendríticas/imunologia , Inflamação/imunologia , Mucosa Intestinal/patologia , Linfócitos T/imunologia , Actomiosina/metabolismo , Animais , Apresentação de Antígeno , Antígenos CD/metabolismo , Antígeno CD11b/metabolismo , Diferenciação Celular , Movimento Celular , Células Cultivadas , Tolerância Imunológica , Cadeias alfa de Integrinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucina-2/imunologia , Tretinoína/metabolismoRESUMO
Infections of the central nervous system are among the most serious infections1,2, but the mechanisms by which pathogens access the brain remain poorly understood. The model microorganism Listeria monocytogenes (Lm) is a major foodborne pathogen that causes neurolisteriosis, one of the deadliest infections of the central nervous system3,4. Although immunosuppression is a well-established host risk factor for neurolisteriosis3,5, little is known about the bacterial factors that underlie the neuroinvasion of Lm. Here we develop a clinically relevant experimental model of neurolisteriosis, using hypervirulent neuroinvasive strains6 inoculated in a humanized mouse model of infection7, and we show that the bacterial surface protein InlB protects infected monocytes from Fas-mediated cell death by CD8+ T cells in a manner that depends on c-Met, PI3 kinase and FLIP. This blockade of specific anti-Lm cellular immune killing lengthens the lifespan of infected monocytes, and thereby favours the transfer of Lm from infected monocytes to the brain. The intracellular niche that is created by InlB-mediated cell-autonomous immune resistance also promotes Lm faecal shedding, which accounts for the selection of InlB as a core virulence gene of Lm. We have uncovered a specific mechanism by which a bacterial pathogen confers an increased lifespan to the cells it infects by rendering them resistant to cell-mediated immunity. This promotes the persistence of Lm within the host, its dissemination to the central nervous system and its transmission.
Assuntos
Doenças do Sistema Nervoso Central , Listeria monocytogenes , Listeriose , Animais , Proteínas de Bactérias/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Doenças do Sistema Nervoso Central/microbiologia , Modelos Animais de Doenças , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Camundongos , Monócitos , VirulênciaRESUMO
Peptidoglycan, the major structural polymer forming the cell wall of bacteria, is an important mediator of physiological and behavioral effects in mammalian hosts. These effects are frequently linked to its translocation from the intestinal lumen to host tissues. However, the modality and regulation of this translocation across the gut barrier has not been precisely addressed. In this study, we characterized the absorption of peptidoglycan across the intestine and its systemic dissemination. We report that peptidoglycan has a distinct tropism for host organs when absorbed via the gut, most notably by favoring access to the brain. We demonstrate that intestinal translocation of peptidoglycan occurs through a microbiota-induced active process. This process is regulated by the parasympathetic pathway via the muscarinic acetylcholine receptors. Together, this study reveals fundamental parameters concerning the uptake of a major microbiota molecular signal from the steady-state gut.
Assuntos
Microbiota , Peptidoglicano , Animais , Peptidoglicano/metabolismo , Bactérias/metabolismo , Parede Celular/metabolismo , Mamíferos/metabolismoRESUMO
Liver involvement is an unusual yet frequently overlooked dengue complication. Pivotal for an efficient clinical management, the early diagnosis of dengue-associated liver involvement relies on an accurate description of its clinical and biological characteristics, its prognosis factors, its association with severe dengue and its clinical management. We conducted a systematic review by searching PubMed and Web of Science databases for original case reports, cohort and cross-sectional studies reporting the clinical and/or biological features of dengue-associated liver involvement. The study was registered in PROSPERO (CRD42021262657). Of the 2552 articles identified, 167 were included. Dengue-associated liver involvement was characterised by clinical features including abdominal pain, hepatomegaly, jaundice, nausea/vomiting, and an echogenic liver exhibiting hepatocellular necrosis and minimal inflammation. Elevated Aspartate Aminotransferase and Alanine Aminotransferase but also elevated bilirubin, Alkaline Phosphatase, gamma-glutamyl transferase, increased International Normalised Ratio, creatinine and creatine kinase, lower albumin and prolonged prothrombin and activated partial thromboplastin time were prevalent in dengue-associated liver involvement. Cardiovascular and haematological systems were frequently affected, translating in a strong association with severe dengue. Liver involvement was more common in males and older adults. It was associated with dengue virus serotype-2 and secondary infections. Early paracetamol intake increased the risk of liver involvement, which clinical management was mostly conservative. In conclusion, this systematic review demonstrates that early monitoring of transaminases, clinical assessment, and ultrasound examination allow an efficient diagnosis of dengue-associated liver involvement, enabling the early identification and management of severe dengue.
Assuntos
Dengue , Humanos , Dengue/diagnóstico , Dengue/complicações , Dengue/patologia , Dengue/virologia , Vírus da Dengue , Fígado/patologia , Fígado/virologia , Fígado/diagnóstico por imagem , Hepatopatias/virologia , Hepatopatias/etiologia , Hepatopatias/patologia , Hepatopatias/diagnósticoRESUMO
Chikungunya virus (CHIKV) is a re-emerging alphavirus that is transmitted to humans by mosquito bites and causes musculoskeletal and joint pain1,2. Despite intensive investigations, the human cellular factors that are critical for CHIKV infection remain unknown, hampering the understanding of viral pathogenesis and the development of anti-CHIKV therapies. Here we identified the four-and-a-half LIM domain protein 1 (FHL1)3 as a host factor that is required for CHIKV permissiveness and pathogenesis in humans and mice. Ablation of FHL1 expression results in the inhibition of infection by several CHIKV strains and o'nyong-nyong virus, but not by other alphaviruses and flaviviruses. Conversely, expression of FHL1 promotes CHIKV infection in cells that do not normally express it. FHL1 interacts directly with the hypervariable domain of the nsP3 protein of CHIKV and is essential for the replication of viral RNA. FHL1 is highly expressed in CHIKV-target cells and is particularly abundant in muscles3,4. Dermal fibroblasts and muscle cells derived from patients with Emery-Dreifuss muscular dystrophy that lack functional FHL15 are resistant to CHIKV infection. Furthermore, CHIKV infection is undetectable in Fhl1-knockout mice. Overall, this study shows that FHL1 is a key factor expressed by the host that enables CHIKV infection and identifies the interaction between nsP3 and FHL1 as a promising target for the development of anti-CHIKV therapies.
Assuntos
Febre de Chikungunya/virologia , Vírus Chikungunya/patogenicidade , Fatores Celulares Derivados do Hospedeiro/metabolismo , Interações Hospedeiro-Patógeno , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas com Domínio LIM/metabolismo , Proteínas Musculares/metabolismo , Animais , Células Cultivadas , Febre de Chikungunya/tratamento farmacológico , Vírus Chikungunya/efeitos dos fármacos , Vírus Chikungunya/genética , Vírus Chikungunya/crescimento & desenvolvimento , Feminino , Fibroblastos/virologia , Células HEK293 , Fatores Celulares Derivados do Hospedeiro/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas com Domínio LIM/deficiência , Proteínas com Domínio LIM/genética , Masculino , Camundongos , Proteínas Musculares/deficiência , Proteínas Musculares/genética , Mioblastos/virologia , Vírus O'nyong-nyong/crescimento & desenvolvimento , Vírus O'nyong-nyong/patogenicidade , Ligação Proteica , RNA Viral/biossíntese , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação ViralRESUMO
Kupffer cells, the phagocytes of fetal origin that line the liver sinusoids, are key contributors of host defense against enteroinvasive bacteria. Here, we found that infection by Listeria monocytogenes induced the early necroptotic death of Kupffer cells, which was followed by monocyte recruitment and an anti-bacterial type 1 inflammatory response. Kupffer cell death also triggered a type 2 response that involved the hepatocyte-derived alarmin interleukin-33 (IL-33) and basophil-derived interleukin-4 (IL-4). This led to the alternative activation of the monocyte-derived macrophages recruited to the liver, which thereby replaced ablated Kupffer cells and restored liver homeostasis. Kupffer cell death is therefore a key signal orchestrating type 1 microbicidal inflammation and type-2-mediated liver repair upon infection. This indicates that beyond the classical dichotomy of type 1 and type 2 responses, these responses can develop sequentially in the context of a bacterial infection and act interdependently, orchestrating liver immune responses and return to homeostasis, respectively.
Assuntos
Células de Kupffer/fisiologia , Listeria monocytogenes/imunologia , Listeriose/imunologia , Fígado/patologia , Monócitos/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Via Alternativa do Complemento , Homeostase , Inflamação/microbiologia , Interleucina-33 , Interleucina-4/metabolismo , Interleucinas/metabolismo , Células de Kupffer/microbiologia , Fígado/microbiologia , Camundongos , Camundongos Endogâmicos , Monócitos/microbiologia , Necrose , Fagocitose , CicatrizaçãoRESUMO
Listeriolysin S (LLS) is a thiazole/oxazole-modified microcin (TOMM) produced by hypervirulent clones of Listeria monocytogenes LLS targets specific gram-positive bacteria and modulates the host intestinal microbiota composition. To characterize the mechanism of LLS transfer to target bacteria and its bactericidal function, we first investigated its subcellular distribution in LLS-producer bacteria. Using subcellular fractionation assays, transmission electron microscopy, and single-molecule superresolution microscopy, we identified that LLS remains associated with the bacterial cell membrane and cytoplasm and is not secreted to the bacterial extracellular space. Only living LLS-producer bacteria (and not purified LLS-positive bacterial membranes) display bactericidal activity. Applying transwell coculture systems and microfluidic-coupled microscopy, we determined that LLS requires direct contact between LLS-producer and -target bacteria in order to display bactericidal activity, and thus behaves as a contact-dependent bacteriocin. Contact-dependent exposure to LLS leads to permeabilization/depolarization of the target bacterial cell membrane and adenosine triphosphate (ATP) release. Additionally, we show that lipoteichoic acids (LTAs) can interact with LLS and that LTA decorations influence bacterial susceptibility to LLS. Overall, our results suggest that LLS is a TOMM that displays a contact-dependent inhibition mechanism.
Assuntos
Bacteriocinas/metabolismo , Membrana Celular/metabolismo , Proteínas Hemolisinas/metabolismo , Listeria monocytogenes/metabolismo , Trifosfato de Adenosina/metabolismo , Citoplasma/metabolismoRESUMO
Genomic data on the foodborne pathogen Listeria monocytogenes from Central America are scarce. We analyzed 92 isolates collected during 2009-2019 from different regions in Costa Rica, compared those to publicly available genomes, and identified unrecognized outbreaks. Our findings suggest mandatory reporting of listeriosis in Costa Rica would improve pathogen surveillance.
Assuntos
Doenças Transmitidas por Alimentos , Listeria monocytogenes , Listeriose , Humanos , Listeria monocytogenes/genética , Doenças Transmitidas por Alimentos/epidemiologia , Costa Rica/epidemiologia , Microbiologia de Alimentos , Listeriose/epidemiologia , Surtos de DoençasRESUMO
BACKGROUND: An outbreak of listeriosis was identified in South Africa in 2017. The source was unknown. METHODS: We conducted epidemiologic, trace-back, and environmental investigations and used whole-genome sequencing to type Listeria monocytogenes isolates. A case was defined as laboratory-confirmed L. monocytogenes infection during the period from June 11, 2017, to April 7, 2018. RESULTS: A total of 937 cases were identified, of which 465 (50%) were associated with pregnancy; 406 of the pregnancy-associated cases (87%) occurred in neonates. Of the 937 cases, 229 (24%) occurred in patients 15 to 49 years of age (excluding those who were pregnant). Among the patients in whom human immunodeficiency virus (HIV) status was known, 38% of those with pregnancy-associated cases (77 of 204) and 46% of the remaining patients (97 of 211) were infected with HIV. Among 728 patients with a known outcome, 193 (27%) died. Clinical isolates from 609 patients were sequenced, and 567 (93%) were identified as sequence type 6 (ST6). In a case-control analysis, patients with ST6 infections were more likely to have eaten polony (a ready-to-eat processed meat) than those with non-ST6 infections (odds ratio, 8.55; 95% confidence interval, 1.66 to 43.35). Polony and environmental samples also yielded ST6 isolates, which, together with the isolates from the patients, belonged to the same core-genome multilocus sequence typing cluster with no more than 4 allelic differences; these findings showed that polony produced at a single facility was the outbreak source. A recall of ready-to-eat processed meat products from this facility was associated with a rapid decline in the incidence of L. monocytogenes ST6 infections. CONCLUSIONS: This investigation showed that in a middle-income country with a high prevalence of HIV infection, L. monocytogenes caused disproportionate illness among pregnant girls and women and HIV-infected persons. Whole-genome sequencing facilitated the detection of the outbreak and guided the trace-back investigations that led to the identification of the source.
Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Produtos da Carne/microbiologia , Adolescente , Adulto , Idoso , Técnicas de Tipagem Bacteriana , Estudos de Casos e Controles , Feminino , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/mortalidade , Infecções por HIV/complicações , HIV-1 , Humanos , Recém-Nascido , Listeria monocytogenes/genética , Listeriose/etiologia , Listeriose/mortalidade , Masculino , Produtos da Carne/efeitos adversos , Pessoa de Meia-Idade , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Recall e Retirada de Produto , Distribuição por Sexo , África do Sul/epidemiologia , Sequenciamento Completo do Genoma , Adulto JovemRESUMO
BACKGROUND: Listeriosis is caused by the foodborne pathogen Listeria monocytogenes. It can present as a maternal-neonatal infection. We implemented a nationwide prospective cohort and analyzed the features of neonatal listeriosis. METHODS: We studied all neonates born alive from mothers with microbiologically proven maternal-neonatal listeriosis enrolled from November 2009 to December 2017. We analyzed presentation, neonatal outcome at discharge, and predictors of severe presentation and outcome. RESULTS: We studied 189 infants; 133 of 189 (70%) had abnormal clinical status at birth, including acute respiratory distress in 106 of 189 (56%). There were 132 of 189 (70%) infants who developed early-onset listeriosis and 12 of 189 (6%) who developed late-onset listeriosis; all presented with acute meningitis. There were 17 of 189 (9%) infants who had major adverse outcomes: 3%, (5 of 189) death; 6% (12 of 189), severe brain injury; and 2% (3 of 189), severe bronchopulmonary dysplasia. Fifteen of 17 infants were born <34 weeks of gestation (Pâ <â .0001 vs infants born ≥34 weeks of gestation). Maternal antimicrobial treatment ≥1 day before delivery was associated with a significant decrease in presentation severity for the infant, resulting in significantly fewer inotropic drugs, fluid resuscitation, and mechanical ventilation requirement (odds ratio, 0.23; 95% confidence interval, 0.09-0.51; Pâ <â .0001). CONCLUSIONS: Antenatal maternal antimicrobial treatment is associated with reduced neonatal listeriosis severity, justifying the prescription of preemptive maternal antimicrobial therapy when maternal-fetal listeriosis is suspected. Neonatal outcome is better than reported earlier, and its major determinant is gestational age at birth. CLINICAL TRIALS REGISTRATION: NCT01520597.
Assuntos
Doenças do Recém-Nascido , Listeria monocytogenes , Listeriose , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Doenças do Recém-Nascido/epidemiologia , Doenças do Recém-Nascido/microbiologia , Listeriose/diagnóstico , Listeriose/tratamento farmacológico , Listeriose/epidemiologia , Gravidez , Estudos ProspectivosRESUMO
During microbial assessment of cow milk cheese products in the city of Ilorin, Nigeria, a Listeria-like isolate was detected that could not be assigned to any known species. Whole-genome sequence analyses against all currently known 26 Listeria species confirmed that this isolate constitutes a new taxon within the genus Listeria, with highest similarity to Listeria costaricensis (average nucleotide identity blast of 82.66%, in silico DNA-DNA hybridization of 28.3%). Phenotypically, it differs from L. costaricensis by the inability to ferment sucrose, l-fucose and starch. The absence of haemolysis and Listeria pathogenic islands suggest that this novel species is not pathogenic for humans and animals. The name Listeria ilorinensis sp. nov. is proposed, with the type strain CLIP 2019/01311T (=CIP 111875T=DSM 111566T).
Assuntos
Queijo , Listeria , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Bovinos , DNA Bacteriano/genética , Ácidos Graxos/química , Feminino , Leite , Nigéria , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
Prolonged measles virus detection in maternal saliva and blood was evidenced in 6 pregnant women. Maternal-fetal transmission was evidenced in 2 of 4 infants who were asymptomatic at birth, 21-24 weeks after maternal infection. Whereas peripartum congenital measles is severe, asymptomatic measles virus vertical transmission can occur earlier in pregnancy.
Assuntos
Sarampo , Complicações Infecciosas na Gravidez , Feminino , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Vírus do Sarampo , Parto , GravidezRESUMO
Outcome of patients with X-linked agammaglobulinemia (XLA) has improved with the widespread use of immunoglobulin replacement therapy (IgRT). There are few data on the spectrum of infections experienced by patients undergoing IgRT. We carried out a retrospective cross-sectional analysis of the records of XLA patients seen at Necker-Enfants Malades Hospital, Paris. For each infection, we evaluated infection site, microbial etiology, antibiotic prophylaxis, immunosuppressive treatment, IgRT route, and last known IgG trough level. Sixty patients were included, who cumulated a follow-up of 1470 patient-years. We recorded 188 infections, including 97 after initiation of IgRT. The rate of infection was highest before IgRT (0.66 vs. 0.06 per person-year (ppy), p < 0.001) and was higher after the age of 16 compared to before (0.14 vs. 0.05 ppy, p = 0.048). It was similar for patients receiving intravenous or subcutaneous Ig (0.09 vs 0.05 ppy, p = 0.54). The lungs and gastrointestinal tract accounted for 71% of infection sites. Forty-six (47%) infections occurred in patients receiving antibiotic prophylaxis. Sixteen (16.5%) infections occurred in patients receiving immunosuppressive therapy, which more frequently occurred after age 16 (35% vs. 2.4%, p < 0.001). The median IgG trough level prior to all infections was 8.4 g/L. Almost half (44.3%) of infections occurred with prior IgG trough levels > 8 g/L, and 16/97 (16.7%) in patients with trough levels > 10 g/L. Infection remains a significant issue in patients with XLA undergoing IgRT despite adequate IgG trough levels. Chronic inflammatory manifestations of X-linked agammaglobulinemia and immunosuppressive therapies may be significant drivers of infection during adulthood.
Assuntos
Agamaglobulinemia/imunologia , Doenças Genéticas Ligadas ao Cromossomo X/imunologia , Infecções/imunologia , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulinas Intravenosas/imunologia , Imunossupressores/imunologia , Lactente , Masculino , Estudos RetrospectivosRESUMO
Studies have shown that ruminants constitute reservoirs of Listeria monocytogenes, but little is known about the epidemiology and genetic diversity of this pathogen within farms. Here we conducted a large-scale longitudinal study to monitor Listeria spp. in 19 dairy farms during three consecutive seasons (N = 3251 samples). L. innocua was the most prevalent species, followed by L. monocytogenes. Listeria monocytogenes was detected in 52.6% of farms and more frequently in cattle (4.1%) and sheep (4.5%) than in goat farms (0.2%). Lineage I accounted for 69% of L. monocytogenes isolates. Among animal samples, the most prevalent sublineages (SL) and clonal complexes (CC) were SL1/CC1, SL219/CC4, SL26/CC26 and SL87/CC87, whereas SL666/CC666 was most prevalent in environmental samples. Sixty-one different L. monocytogenes cgMLST types were found, 28% common to different animals and/or surfaces within the same farm and 21% previously reported elsewhere in the context of food and human surveillance. Listeria monocytogenes prevalence was not affected by farm hygiene but by season: higher prevalence was observed during winter in cattle, and during winter and spring in sheep farms. Cows in their second lactation had a higher probability of L. monocytogenes faecal shedding. This study highlights dairy farms as a reservoir for hypervirulent L. monocytogenes.
Assuntos
Listeria monocytogenes , Listeriose , Animais , Bovinos , Células Clonais , Fazendas , Feminino , Listeriose/epidemiologia , Estudos Longitudinais , Ruminantes , OvinosRESUMO
The intracellular pathogen Listeria monocytogenes is distinguished by its ability to invade and replicate within mammalian cells. Remarkably, of the 15 serovars within the genus, strains belonging to serovar 4b cause the majority of listeriosis clinical cases and outbreaks. The Listeria O-antigens are defined by subtle structural differences amongst the peptidoglycan-associated wall-teichoic acids (WTAs), and their specific glycosylation patterns. Here, we outline the genetic determinants required for WTA decoration in serovar 4b L. monocytogenes, and demonstrate the exact nature of the 4b-specific antigen. We show that challenge by bacteriophages selects for surviving clones that feature mutations in genes involved in teichoic acid glycosylation, leading to a loss of galactose from both wall teichoic acid and lipoteichoic acid molecules, and a switch from serovar 4b to 4d. Surprisingly, loss of this galactose decoration not only prevents phage adsorption, but leads to a complete loss of surface-associated Internalin B (InlB),the inability to form actin tails, and a virulence attenuation in vivo. We show that InlB specifically recognizes and attaches to galactosylated teichoic acid polymers, and is secreted upon loss of this modification, leading to a drastically reduced cellular invasiveness. Consequently, these phage-insensitive bacteria are unable to interact with cMet and gC1q-R host cell receptors, which normally trigger cellular uptake upon interaction with InlB. Collectively, we provide detailed mechanistic insight into the dual role of a surface antigen crucial for both phage adsorption and cellular invasiveness, demonstrating a trade-off between phage resistance and virulence in this opportunistic pathogen.
Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófagos/patogenicidade , Parede Celular/metabolismo , Galactose/metabolismo , Listeria monocytogenes/virologia , Proteínas de Membrana/metabolismo , Ácidos Teicoicos/metabolismo , Virulência , Proteínas de Bactérias/genética , Bacteriófagos/genética , Células CACO-2 , Células Hep G2 , Humanos , Listeria monocytogenes/metabolismo , Proteínas de Membrana/genética , Mutação , SorogrupoRESUMO
Listeria monocytogenes is a major human and animal foodborne pathogen. However, data from environmental reservoirs remain scarce. Here, we used whole-genome sequencing to characterize Listeria species isolates recovered over 1 year from wild animals in their natural habitats in Spain. Three different Listeria spp. (L. monocytogenes [n = 19], Listeria ivanovii subsp. londoniensis [n = 4], and Listeria innocua [n = 3]) were detected in 23 animal tonsils (9 deer, 14 wild boars) and 2 feeding troughs. No Listeria species was detected in feces. L. monocytogenes was detected in tonsils of 44.4% (8 out of 18) of deer and 40.7% (11 out of 27) of wild boars. L. monocytogenes isolates belonged to 3 different core genome multilocus sequence typing (cgMLST) types (CTs) of 3 distinct sublineages (SL1, SL387, and SL155) from lineages I and II. While cgMLST type L1-SL1-ST1-CT5279 (IVb; clonal complex 1 [CC1]) occurred only in one animal, types L1-SL387-ST388-CT5239 (IVb; CC388) and L2-SL155-ST155-CT1170 (IIa; CC155) were retrieved from multiple animals. In addition, L1-SL387-ST388-CT5239 (IVb; CC388) isolates were collected 1 year apart, revealing their long-term occurrence within the animal population and/or environmental reservoir. The presence of identical L. monocytogenes strains in deer and wild boars suggests contamination from a common food or environmental source, although interhost transmission cannot be excluded. Pathogenicity islands LIPI-1, LIPI-3, and LIPI-4 were present in 100%, 5%, and 79% of the L. monocytogenes isolates, respectively, and all L. monocytogenes lineage II isolates (n = 3) carried SSI-1 stress islands. This study highlights the need for monitoring L. monocytogenes environmental contamination and the importance of tonsils as a possible L. monocytogenes intrahost reservoir.IMPORTANCEListeria monocytogenes is a foodborne bacterial pathogen responsible for listeriosis. Whole-genome sequencing has been extensively used in public health and food industries to characterize circulating Listeria isolates, but genomic data on isolates occurring in natural environments and wild animals are still scarce. Here, we show that wild animals carry pathogenic Listeria and that the same genotypes can be found at different time points in different host species. This work highlights the need of Listeria species monitoring of environmental contamination and the importance of tonsils as a possible L. monocytogenes intrahost reservoir.
Assuntos
Cervos/microbiologia , Listeria/genética , Listeriose/microbiologia , Tonsila Palatina/microbiologia , Sus scrofa/microbiologia , Animais , Fezes/microbiologia , Genoma Bacteriano , Listeria/isolamento & purificação , Listeriose/veterinária , Tipagem de Sequências Multilocus , Filogenia , Sequenciamento Completo do GenomaRESUMO
Chikungunya nephropathy is an uncommon etiology of acute kidney injury, associated with the mosquito-borne chikungunya arbovirus (CHIKV). The very limited number of pathologic reports to date have only involved postmortem analyses. We here report 5 cases of acute kidney injury for which kidney biopsies were performed in patients with confirmed acute CHIKV infection, during the recent outbreak of chikungunya disease in the French West Indies. The patients ranged from 42 to 76 years of age. All of the patients developed kidney injury, 3 of whom required short-term dialysis and underwent a kidney biopsy. Analysis of kidney biopsies revealed 2 main histopathologic patterns: acute interstitial nephritis with predominant lymphoid inflammation and acute tubular injury. Epithelioid granulomas were observed in 2 cases. There were no glomerular lesions, except in biopsies from 2 patients, including 1 with a previous known primary focal segmental glomerulosclerosis. CHIKV antigen immunofluorescence microscopy revealed staining in tubular cells. In all of the cases, the short-term outcome was favorable, with recovery of kidney function.
Assuntos
Injúria Renal Aguda , Febre de Chikungunya , Nefrite Intersticial , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Animais , Biópsia , Febre de Chikungunya/complicações , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Humanos , RimRESUMO
Listeria monocytogenes causes listeriosis, a systemic infection which manifests as bacteremia, often complicated by meningoencephalitis in immunocompromised individuals and the elderly, and fetal-placental infection in pregnant women. It has emerged over the past decades as a major foodborne pathogen, responsible for numerous outbreaks in Western countries, and more recently in Africa. L. monocytogenes' pathogenic properties have been studied in detail, thanks to concomitant advances in biological sciences, in particular molecular biology, cell biology and immunology. L. monocytogenes has also been instrumental to basic advances in life sciences. L. monocytogenes therefore stands both a tool to understand biology and a model in infection biology. This review briefly summarises the clinical and some of the pathophysiological features of listeriosis. In the context of this special issue, it highlights some of the major discoveries made by Pascale Cossart in the fields of molecular and cellular microbiology since the mid-eighties regarding the identification and characterisation of multiple bacterial and host factors critical to L. monocytogenes pathogenicity. It also briefly summarises some of the key findings from our laboratory on this topic over the past years.
Assuntos
Interações Hospedeiro-Patógeno , Listeria monocytogenes/patogenicidade , Listeriose/microbiologia , Listeriose/fisiopatologia , Animais , Microbiologia de Alimentos , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/imunologia , Listeriose/imunologia , Camundongos , Sepse/complicações , Sepse/microbiologiaRESUMO
Patients treated for adult T-Cell leukemia/lymphoma (ATL) have a poor prognosis and are prone to infectious complications which are poorly described. As the French reference center for ATL, we retrospectively analyzed 47 consecutive ATL (acute, n = 23; lymphoma, n = 14; chronic, n = 8; smoldering, n = 2) patients between 2006 and 2016 (median age 51 years, 96% Afro-Caribbean origin). The 3-year overall survival (OS) was 15.8%, 11.3%, and 85.7% for acute, lymphoma, and indolent (chronic and smoldering) forms respectively. Among aggressive subtypes, 20 patients received, as frontline therapy, high dose of zidovudine and interferon alfa (AZT-IFNâº) resulting in an overall response rate (ORR) of 39% (complete response [CR] 33%) and 17 chemotherapy resulting of an ORR of 59% (CR 50%). Ninety-five infections occurred in 38 patients, most of whom had an acute subtype (n = 73/95; 77%). During their follow-up, patients receiving frontline chemotherapy or frontline AZT-IFNα developed infections in 74% (n = 14/19) and 89% (n = 24/27) of the cases respectively. Sixty-four (67%) of infections were microbiologically documented. Among them, invasive fungal infections (IFI, n = 11) included 2 Pneumocystis jirovecii pneumonia, 5 invasive aspergillosis, and 4 yeast fungemia. IFI exclusively occurred in patients with acute subtype mostly exposed to AZT-IFNα (n = 10/11) and experiencing prolonged (> 10 days) grade 4 neutropenia. Patients with aggressive subtype experiencing IFI had a lower OS than those who did not (median OS 5.4 months versus 18.4 months, p = 0.0048). ATL patients have a poor prognosis even in the modern era. Moreover, the high rate of infections impacts their management especially those exposed to AZT-IFNα.