Listeria monocytogenes infection in pregnant macaques alters the maternal gut microbiome†.

OBJECTIVES: The bacterium Listeria monocytogenes (Lm) is associated with adverse pregnancy outcomes. Infection occurs through consumption of contaminated food that is disseminated to the maternal-fetal interface. The influence on the gastrointestinal microbiome during Lm infection remains unexplored in pregnancy. The objective of this study was to determine the impact of listeriosis on the gut microbiota of pregnant macaques. METHODS: A non-human primate model of listeriosis in pregnancy has been previously described. Both pregnant and non-pregnant cynomolgus macaques were inoculated with Lm and bacteremia and fecal shedding were monitored for 14 days. Non-pregnant animal tissues were collected at necropsy to determine bacterial burden, and fecal samples from both pregnant and non-pregnant animals were evaluated by 16S rRNA next-generation sequencing. RESULTS: Unlike pregnant macaques, non-pregnant macaques did not exhibit bacteremia, fecal shedding, or tissue colonization by Lm. Dispersion of Lm during pregnancy was associated with a significant decrease in alpha diversity of the host gut microbiome, compared to non-pregnant counterparts. The combined effects of pregnancy and listeriosis were associated with a significant loss in microbial richness, although there were increases in some genera and decreases in others. CONCLUSIONS: Although pregnancy alone is not associated with gut microbiome disruption, we observed dysbiosis with listeriosis during pregnancy. The macaque model may provide an understanding of the roles that pregnancy and the gut microbiota play in the ability of Lm to establish intestinal infection and disseminate throughout the host, thereby contributing to adverse pregnancy outcomes and risk to the developing fetus.

Epidemiology, clinical and imaging features of rhombencephalitis caused by L. monocytogenes. A retrospective observational study. / Epidemiología, clínica y resultados de imagen de rombencefalitis causada por L. monocytogenes. Un estudio observacional.

INTRODUCTION: To date, few studies have explored the specific risk factors of patients with listeriosis who develop rhombencephalitis, and there is insufficient information regarding imaging findings and clinical symptoms in patients with this disease. This work aimed to analyze the imaging findings associated with L. monocytogenes rhombencephalitis in a cohort of patients with listeriosis. MATERIALS AND METHODS: We conducted a retrospective observational study of all declared cases of listeriosis in a tertiary hospital from Granada, Spain, from 2008 to 2021. Risk factors, comorbidities, and clinical outcomes were collected for all patients. In addition, clinical symptoms and magnetic resonance imaging (MRI) findings were included for those patients who developed rhombencephalitis. Descriptive and bivariate analyses were performed using SPSS statistical software (IBM SPSS, version 21). RESULTS: Our cohort comprised 120 patients with listeriosis (41.7% women, mean age: 58.6 ± 23.8 years), of which 10 (8.3%) had rhombencephalitis. The most frequent MRI findings in patients with confirmed rhombencephalitis were T2-FLAIR hyperintensity (100%), T1 hypointensity (80%), scattered parenchymal enhancement (80%), and cranial nerve enhancement (70%), while the most frequent anatomical involvement were pons, medulla oblongata, and cerebellum. Complications occurred in 6 patients (abscess in 4, hemorrhage in 2, hydrocephalus in 1). CONCLUSIONS: Rhombencephalitis is associated with an increased in-hospital mortality in patients with listeriosis. The anatomical distribution and imaging characteristics of neurolisteriosis could be useful to suggest the diagnosis. Future studies with greater sample size should explore the association between anatomical location, imaging patterns, and associated complications (e.g., hydrocephalus, hemorrhage), and clinical outcomes.

TITLE: Epidemiología, clínica y resultados de imagen de rombencefalitis causada por L. monocytogenes. Un estudio observacional.Introducción. Hasta la fecha, pocos estudios han explorado los factores de riesgo específicos de los pacientes con listeriosis que desarrollan rombencefalitis, y no hay suficiente información sobre los hallazgos de imagen y los síntomas clínicos en pacientes con esta enfermedad. El objetivo de este trabajo fue analizar los hallazgos de imagen asociados a la rombencefalitis por L. monocytogenes en una cohorte de pacientes con listeriosis. Materiales y métodos. Se realizó un estudio observacional retrospectivo de todos los casos declarados de listeriosis en un hospital terciario de Granada, España, desde 2008 hasta 2021. Se recogieron los factores de riesgo, las comorbilidades y los resultados clínicos de todos los pacientes. Además, se incluyeron los síntomas clínicos y los hallazgos de resonancia magnética (RM) de los pacientes que desarrollaron rombencefalitis. Se realizaron análisis descriptivos y bivariados utilizando el software estadístico SPSS (IBM SPSS, versión 21). Resultados. Nuestra cohorte incluyó a 120 pacientes con listeriosis (41,7%, mujeres; edad media: 58,6 ± 23,8 años), de los cuales 10 (8,3%) tenían rombencefalitis. Los hallazgos más frecuentes en la RM de los pacientes con rombencefalitis confirmada fueron hiperintensidad en T2-FLAIR (100%), hipointensidad en T1 (80%), realce parenquimatoso disperso (80%) y realce de los nervios craneales (70%), mientras que la afectación anatómica más frecuente fue en la protuberancia, la médula oblongada y el cerebelo. Se produjeron complicaciones en seis pacientes (absceso en cuatro, hemorragia en dos e hidrocefalia en uno). Conclusiones. La rombencefalitis se asocia a un aumento de la mortalidad intrahospitalaria en pacientes con listeriosis. La distribución anatómica y las características de imagen de la neurolisteriosis podrían ser útiles para sugerir el diagnóstico. Futuros estudios con mayor tamaño muestral deberían explorar la asociación entre la localización anatómica, los patrones de imagen y las complicaciones asociadas (por ejemplo, hidrocefalia y hemorragia), y los resultados clínicos.

Risk factors and mortality in patients with listeriosis and end-stage renal disease.

BACKGROUND: End-stage renal disease (ESRD) is a known immunocompromising status that predisposes patients to developing infections. Disease from Listeria monocytogenes may affect any host but tends to be more severe in the immunocompromised. METHODS: We used a large population of patients with ESRD to identify risk factors for listeriosis and mortality. Patients with a diagnosis of Listeria and other risk factors for listeriosis were identified using claims data from the United States Renal Data System database from 2004-2015. Demographic parameters and risk factors associated with Listeria were modeled using logistic regression while association with mortality was assessed with Cox Proportional Hazards modeling. RESULTS: A diagnosis of Listeria was identified in 291 (0.01%) of a total 1,071,712 patients with ESRD. Cardiovascular disease, connective tissue disease, upper gastrointestinal ulcerative disease, liver disease, diabetes, cancer, and human immunodeficiency virus were all associated with an increased risk of Listeria. Patients with Listeria had an increased risk of death relative to patients without Listeria (adjusted hazard ratio=1.79; 95% confidence interval 1.52-2.10). CONCLUSIONS: Incidence of listeriosis in our study population was over 7 times higher than what has been reported for the general population. The independent association of a Listeria diagnosis with increased mortality is also consistent with the disease's high mortality in the general population. Due to limitations with diagnosis, providers should maintain high clinical suspicion for listeriosis when patients with ESRD present with a compatible clinical syndrome. Further prospective study may help precisely quantify the increased risk of listeriosis in patients with ESRD.

Spontaneous bacterial peritonitis caused by Listeria monocytogenes: A rare infection with very high leukocyte counts in ascitic fluid-case report and review of the literature.

We present a rare case of Listeria monocytogenes-induced spontaneous bacterial peritonitis (SBP) in cirrhosis. Examination of the patient's peritoneal fluid revealed an extremely high leukocyte count. We suspect, that the patient belongs to 1% of individuals in which Listeria monocytogenes is part of the intestinal flora. Cephalosporins as empiric antibiotics have a Listeria gap. A combination of aminopenicillin and aminoglycoside is recommended. Therefore, early microbiological diagnosis from ascites and blood is essential. Listeria should be considered as a rare cause of SBP, especially in case of very high leukocyte count in peritoneal fluid or lack of response to empiric therapy.

Listeria rhombencephalitis mimicking stroke in a patient with giant cell arteritis.

Listeria monocytogenes sometimes causes central nervous system infections. However, rhombencephalitis is a rare form of L. monocytogenes infection. Its clinical symptoms and magnetic resonance imaging (MRI) findings are often similar to those of vertebrobasilar stroke. We present the case of a 79-year-old woman with Listeria rhombencephalitis presenting with rhinorrhea and productive cough. She had giant cell arteritis (GCA) treated with prednisolone and methotrexate. She was admitted for loss of appetite, rhinorrhea, and productive cough. These symptoms were alleviated without specific treatment; however, she suddenly developed multiple cranial nerve palsies, and MRI showed hyperintense signals on diffusion-weighted imaging and hypointense signals on apparent diffusion coefficient in the brainstem. Ischemic stroke due to exacerbation of GCA was suspected, and treatment with intravenous methylprednisolone was initiated; however, seizures occurred, and a lumbar puncture was performed. Cerebrospinal fluid and blood cultures revealed L. monocytogenes, and she was diagnosed with Listeria rhombencephalitis. Although antibiotic treatment was continued, the patient died. Thus, when patients with rhinorrhea or productive cough develop sudden cranial nerve palsy, Listeria rhombencephalitis should be considered as a differential diagnosis, and lumbar puncture should be performed.

Complications Associated with Foodborne Listeriosis: A Scoping Review.

Listeria monocytogenes is a relatively rare but highly pathogenic bacterium that can cause foodborne infections. In the United States there are ∼1600 cases per year, 94% of which result in hospitalizations and 20% in deaths. Per-case burden is high because the disease also causes serious complications, including sepsis, encephalitis, meningitis, miscarriage, and stillbirth. The disease burden of L. monocytogenes is underestimated because some of these acute complications can also result in long-term outcomes. In this article, we conducted a scoping review of L. monocytogenes complications and longer term outcomes from articles published between 2000 and 2018. Search terms were developed for four major databases (PubMed, Scopus, Web of Science, and Embase) as well as gray literature and hand searches of review articles. We follow standard scoping review methodology and assessment. Out of 10,618 unique articles originally identified, 115 articles were included, representing 49 unique outcomes. The majority of studies were cohort designs (n = 67) and conducted in the United States or Europe (n = 98). Four major outcome groupings were death, neurological disorders, sepsis, and congenital infection. This study identifies substantial research on the common acute complications of L. monocytogenes and few long-term consequences of L. monocytogenes. We identify the need for additional studies to determine the longer term impacts of these acute complications.

Maternal sepsis caused by Listeria monocytogenes with a fatal fetal outcome.

Improving maternal and child health is a global priority. Although infection with Listeria monocytogenes (LM), a small facultative anaerobic, gram-positive motile bacillus is rare, when it infects the maternal-fetoplacental unit, it can result in adverse fetal sequelae such as chorioamnionitis, preterm labour, neonatal sepsis, meningitis and neonatal death. Pregnancy-associated listeriosis may present with a plethora of diverse, non-specific symptoms such as fever, influenza-like or gastrointestinal symptoms, premature contractions and preterm labour. It has a predilection for the second and third trimester of pregnancy, occurring sporadically or as part of an outbreak, most of which have involved unpasteurised dairy products, long shelf life products, contaminated ready-to-eat food, deli meats and soft cheeses. Strains belonging to the clonal complexes 1, 4 and 6 are hypervigilant and are commonly associated with maternal-neonatal infections. Maternal listeriosis occurs as a direct consequence of LM-specific placental tropism, which is mediated by the conjugated action of internalin A and internalin B at the placental barrier. The diagnosis is established from placental culture. Penicillin, ampicillin and amoxicillin are the antimicrobials of choice. It has a high fetal morbidity of up to 30%. The authors present the case of a multiparous woman in her early 20s presenting with sepsis and preterm premature rupture of her membranes at 21 weeks gestation. A live baby was delivered spontaneously and died shortly after birth. Placental cultures and postmortem examination were consistent with the diagnosis of disseminated Listeria infection. Due to the increased susceptibility of pregnant women for LM, a high index of clinical suspicion is required to establish the diagnosis and initiate appropriate antimicrobial therapy to reduce adverse fetal outcomes.

Fatal Listeria monocytogenes septicemia and meningitis complicated by Candida glabrata fungemia: a case report.

Listeria monocytogenes is a Gram-positive bacteria and etiological agent of listeriosis. It has the ability to colonize the intestinal lumen and cross the intestinal, blood-brain, and placental barriers, leading to invasive listeriosis responsible for septicemia and meningitis in subjects at risk such as patients with diabetes mellitus, the elderly, and immunocompromised individuals and, for maternal-neonatal infection in pregnant women. We report a rare case of L. monocytogenes septicemia and meningitis complicated by Candida glabrata fungemia on a patient with a history of type 2 diabetes mellitus, hypothyroidism, hypertension, chronic kidney failure, chronic ischemic vascular encephalopathy, and atrial fibrillation. Although adequate therapy was rapidly started with an initial partial clinical improvement, the patient suddenly experienced clinical worsening concomitantly with Candida septicemia resulting in a fatal outcome. To our knowledge, this is the first described case of an invasive L. monocytogenes infection complicated by Candida sepsis. We hypothesize that concomitant Candida infection may play a significant role in the pathogenesis and virulence of L. monocytogenes.

Infection with Listeria monocytogenes alters the placental transcriptome and eicosanome.

INTRODUCTION: Placental infection and inflammation are risk factors for adverse pregnancy outcomes, including preterm labor. However, the mechanisms underlying these outcomes are poorly understood. METHODS: To study this response, we have employed a pregnant mouse model of placental infection caused by the bacterial pathogen Listeria monocyogenes, which infects the human placenta. Through in vivo bioluminescence imaging, we confirm the presence of placental infection and quantify relative infection levels. Infected and control placentas were collected on embryonic day 18 for RNA sequencing to evaluate gene expression signatures associated with infection by Listeria. RESULTS: We identified an enrichment of genes associated with eicosanoid biosynthesis, suggesting an increase in eicosanoid production in infected tissues. Because of the known importance of eicosanoids in inflammation and timing of labor, we quantified eicosanoid levels in infected and uninfected placentas using semi-targeted mass spectrometry. We found a significant increase in the concentrations of several key eicosanoids: leukotriene B4, lipoxin A4, prostaglandin A2, prostaglandin D2, and eicosatrienoic acid. DISCUSSION: Our study provides a likely explanation for dysregulation of the timing of labor following placental infection. Further, our results suggest potential biomarkers of placental pathology and targets for clinical intervention.

Brain abscess caused by Listeria monocytogenes: a case report and literature review.

BACKGROUND: Listeria monocytogenes (L. monocytogenes) is an opportunistic facultative anaerobic pathogen that is widely distributed in nature. Brain infection (meningitis and meningoencephalitis) and bacteremia are common clinical manifestations of listeriosis in elderly and immunocompromised individuals. Brain abscesses caused by L. monocytogenes are extremely rare. In this study, we describe a case of an older male who with a brain abscess caused by Listeria infection. CASE DESCRIPTION: We report a case of a 59-year-old male who was once diagnosed with acute cerebral infarction. The diagnose was changed after needle biopsy of the abscess and culture of L. monocytogenes. The patient was first empirically used the broad-spectrum antibiotic meropenem for 12 days (2 g Q8 h) until culture results were available, and then switched to oral trimethoprim/sulfamethoxazole 160/800 mg/12 h for further 2 weeks. The symptoms of slurred speech, numbness and impaired muscle strength of the right leg improved. Computed tomography (CT) and magnetic resonance imaging (MRI) examination were performed 2 weeks after operation showed smaller abscess and reduced perifocal edema. The patient was continued oral trimethoprim/sulfamethoxazole for 8 weeks. The remaining right arm dysfunction recovered. After six months, the patient had returned to normal daily activities and only exhibited weakness of the right fingers. CONCLUSIONS: Brain abscess caused by L. monocytogenes should be considered in patients who have risk factors for listeriosis. Pathogen infection, including with Listeria monocytogenes, should be taken into account when patients with impaired immune function exhibit hemiplegia and aphasia. Listeria infection should also be considered in immunocompetent patients. Performing needle biopsy or lesion resection and starting antibiotic therapy according to drug susceptibility testing in the early stage is key to treating this kind of disease.

Methylene blue for the treatment of refractory septic shock secondary to listeriosis in a paediatric patient.

Current therapies frequently used for refractory septic shock include hydrocortisone, vasopressin, extracorporeal membrane oxygenation (ECMO) support, inodilators, levosimendan and methylene blue. The evidence for these treatments is very limited. We present a case of a 5-year-old patient with refractory septic shock, secondary to Listeria monocytogenes meningitis. She presented with status epilepticus and developed septic shock. Shock persisted despite multiple high-dose vasoactive medications. ECMO support was not available. The medical team decided to use methylene blue to revert the vasoplegia, with excellent results. Shortly after the administration, vasopressors were weaned off and the high lactate cleared. She developed severe neurological sequelae due to brain haemorrhage secondary to the Listeria meningitis. The evidence supporting methylene blue for refractory septic shock in paediatric patients is limited. This case represents the effectiveness of this therapy without secondary effects.

Listeriosis in pregnancy: An umbrella review of maternal exposure, treatment and neonatal complications.

BACKGROUND: Listeria monocytogenes is a commonly found organism in processed and prepared food and the disease of listeriosis is associated with a high morbidity and mortality. Compared with the general population, the risk of being diagnosed with listeriosis increases during pregnancy. Listeriosis can lead to miscarriage, spontaneous preterm labour and preterm birth, stillbirth and congenital neonatal infections. OBJECTIVES: We conducted a universal review of listeriosis in pregnancy and in the newborn. SEARCH STRATEGY: The EMBASE, PubMed, Cinahl and Web of Science databases were searched for systematic reviews indexed before 1 December 2020. SELECTION CRITERIA: Any systematic reviews evaluating the prevalence, treatment, diagnosis and effects of listeriosis during pregnancy and up to 4 weeks postnatally were included. DATA COLLECTION AND ANALYSIS: Eligibility assessment, data extraction and quality assessment by the Methodological Quality Assessment of Systematic Reviews (AMSTAR-2) were performed in duplicate. MAIN RESULTS: We identified 397 citations of which nine systematic reviews comprising 330 studies and 487 patients' reviews were included. Most systematic reviews (seven of nine) were of moderate to high quality. Prevention in pregnant women was based on adherence to strict dietary recommendations, such as reheating leftovers until steamed and avoiding unpasteurised dairy products. Listeriosis infections were likely to occur in the third trimester (66%) rather than in the first trimester (3%) of pregnancy. Symptoms are mostly fever and other flu-like symptoms, such as fatigue. Diagnosis was primarily made by culture of the pathogen. Intravenous amoxicillin or ampicillin were first-line treatment. CONCLUSIONS: Listeriosis, a rare but serious infectious disease in pregnancy, can cause devastating consequences for the fetus and newborn. Appropriate preventative treatment should be initiated during early pregnancy to avoid complications. TWEETABLE ABSTRACT: Listeria is commonly found in processed and prepared food. Prevention is the best way to avoid listeriosis during pregnancy.

Perianal Abscess Caused by Listeria monocytogenes.

Listeria monocytogenes can cause gastrointestinal infections in healthy children and adults, but they tend to be mild and self-limiting. It can, however, cause serious potentially lethal infections, such as meningitis and bacteremia, to those with underlying conditions. A woman in her 60s with liver cirrhosis developed abdominal pain and a fever, and she turned out to have a perianal abscess caused by L. monocytogenes. Perianal abscess is a rare complication of L. monocytogenes, but a recent epidemiological study revealed that the presence of cirrhosis might also be a risk factor for the development of invasive disease.

Listeria monocytogenes Ankle Osteomyelitis in a Patient with Rheumatoid Arthritis on Adalimumab: A Report and Literature Review of Listeria monocytogenes Osteomyelitis.

Localized Listeria infection predominantly occurs in the prosthetic and hip joints. We herein report a case of Listeria monocytogenes ankle osteomyelitis in a 73-year-old man receiving adalimumab who was transferred to our hospital because of suspected rheumatoid arthritis (RA) flare. He reported a four-month history of left ankle swelling. A surgical biopsy revealed L. monocytogenes osteomyelitis in the left tibia and talus bones. The patient was successfully treated with antibiotics and surgical debridement. Thus, infection due to L. monocytogenes can present as ankle osteomyelitis in immunocompromised patients and may mimic an RA flare.

Spondylodiscitis After Endovascular Aortic Repair Due to Noninvasive Listeriosis: A Case Report.

CASE: An 83-year-old man suffered progressive lower back pain 4 weeks after an endovascular aortic repair (EVAR) procedure. Computed tomography showed L4 vertebral body collapse and abnormal soft tissue-like density swelling with increased uptake on 18F-fluoro-D-glucose (FDG) positron emission tomography (PET)/CT. Listeria monocytogenes was identified from ultrasound-guided fine-needle aspiration. Ultrasound-guided drainage of the retroperitoneal abscess and intravenous antibiotic therapy with ampicillin and gentamicin resulted in the rapid relief of symptoms. CONCLUSION: Spondylodiscitis after EVAR requires a timely diagnosis. Uncommon organisms such as L. monocytogenes must be suspected, even in focal infections without signs of listeriosis. Conservative treatment with preservation of the graft should be considered as long as close follow-up evaluations are performed.

Prevalence of Listeria monocytogenes fecal carriers in HIV-infected and -uninfected pregnant women from Brazil.

OBJECTIVE: The aim of this study is to describe the prevalence of Listeria spp. in feces of HIV-infected and -uninfected pregnant women in Brazil. METHODS: Cross-sectional study. Women on their second or third trimester of pregnancy were submitted to a clinical questionnaire and feces collection. The feces were inoculated on selective media and identification by biochemical tests combined with PCR. RESULTS: A total of 213 pregnant women were enrolled: 73 (34%) HIV-infected and 140 (66%) -non-infected. The prevalence of Listeria spp. and L. monocytogenes in feces of HIV-infected women were 8.2% and 2.7%. In the HIV-uninfected were 8.6% and 2.9% (p-values = 0.98 and 0.66, respectively). CONCLUSION: The prevalence of fecal carriers of Listeria spp. and L. monocytogenes was not associated with HIV infection during pregnancy.