Listeriosis neonatal un desafío diagnóstico: reporte de caso y revisión de la literatura / Neonatal listeriosis a diagnostic challenge: A case report and review of the literature

Introducción: La listeriosis es una patología de baja incidencia, con síntomas leves y autolimitados en la población en general, sin embargo, la transmisión materno-fetal, puede generar cuadros graves en neonatos, manifestados como sepsis, meningitis, endocarditis, encefalitis, meningoencefalitis. El diagnóstico oportuno por clínica y datos de laboratorio en coyuntura con la terapéutica adecuada favorecen la resolución de la enfermedad. Caso clínico: Neonato prematuro tardío de 34 semanas, 6 días de edad gestacional, nació por cesárea iterativa, al nacimiento no vigoroso con líquido amniótico meconial pesado, requirió reanimación básica y avanzada. Evolución: Por los antecedentes natales se realizó estudio de infección, con reporte positivo y desarrollo en hemocultivos de Listeria Monocytogenes, diagnóstico de sepsis, meningitis y conjuntivitis, recibió antibiótico terapia intrave-nosa, completó tratamiento y presentó evolución clínica favorable. Conclusiones: En el presente caso la listeriosis de transmisión materno-neonatal tuvo una presentación grave con aspiración de líquido meconial que requirió intubación y soporte ventilatorio, el paciente desarrolló meningitis y conjuntivitis. En la placenta se presentó corionitis.

Introduction: Listeriosis is a low-incidence pathology with mild and self-limiting symptoms in the general population; however, maternal-fetal transmission can generate severe conditions in neonates, manifested as sepsis, meningitis, endocarditis, encephalitis, meningoencephalitis. Timely diagnosis by clinical and laboratory data in conjunction with adequate therapy favors the resolution of the disease. Clinical case: Late preterm neonate of 34 weeks, six days of gestational age, was born by repetitive cesarean section at non-vigorous birth with heavy meconium amniotic fluid and required basic and advanced resuscitation. Evolution: Based on the birth history, an infection study was carried out, with a favorable report and development of Listeria Monocytogenes in blood cultures, diagnosis of sepsis, meningitis, and conjunctivitis, received intravenous antibiotic therapy, completed treatment, and presented favorable clinical evolution. Conclusions: In the present case, the listeriosis of maternal-neonatal transmission had a severe presentation with the aspiration of meconium fluid that required intubation and ventilatory support; the patient developed meningitis and conjunctivitis. Chorionitis occurs in the placenta.

Advances in in vitro and in vivo models for Listeria monocytogenes placental infection / 生物工程学报

Listeria monocytogenes is recognized as a significant foodborne pathogen, capable of causing listeriosis in humans, which is a global public health concern. This pathogen is particularly dangerous for pregnant women, as it can lead to invasive listeriosis in fetuses and neonates, posing a significant threat to both maternal and fetal health. Therefore, establishing suitable in vitro and in vivo models for L. monocytogenes placenta infection, as well as analyzing and exploring the infection process and its pathogenic mechanism, are important approaches to prevent and control L. monocytogenes infection in mothers and infants. In this study, we reviewed the in vitro and in vivo placental models used for studying the infection of L. monocytogenes in maternal and infant, summarized and discussed the advantages and limitations of each model, and explored the potential of in vitro cell models and organoids for the study of L. monocytogenes infection. This paper aims to support the study of the infection pathway and pathogenesis of listeriosis and provide scientific references for the prevention and control of L. monocytogenes infection.

Submaxilitis aguda bilateral asociada con listeriosis en un paciente inmunodeprimido / Acute bilateral submaxillitis associated to listeriosis in immunosuppressed patient

Acute bilateral submaxillitis is a rare event, except when it is caused by sialolithiasis. It has been described secondary to allergic, infectious, suppurative or viral processes, autoimmune such as Sjögren's syndrome, drugs such as thiopurines, nitrofurantoin, phenylbutazone, captopril, and after upper airway procedures such as upper endoscopy, orotracheal intubation bronchoscopy and ERCP (endoscopic retrograde cholangiopancreatography for choledocholithiasis). Treatment with tumour necrosis factor-alpha (TNF-alpha) antagonist drugs is associated with an increased risk of reactivation of intracellular bacterial infections, so that listeriosis has been described in pathologies that require such treatment, such as rheumatic, dermatological and intestinal diseases, which present other comorbidities or are immunocompromised. Listeriosis mainly causes bacteremia and meningitis, when symptomatic, and infects immunosuppressed persons, where it has a lethality despite 30% antibiotherapy. We present the clinical case of a male immunosuppressed patient, secondary to a treatment with azathioprine and prednisone followed by adalimumab, for indeterminate inflammatory bowel disease, superinfected by CMV, who after eating meat contaminated by Listeria monocytogenes, suffered a picture of listeriosis bacteremia, which improved with antibiotic treatment, followed by a transient acute bilateral submaxillitis, which subsided with symptomatic treatment (oral hydration). It is the only case described in the literature, in which an immunosuppressed patient treated with adalimumab, suffers from acute bilateral submaxillitis in the context of listeriosis, caused by the mumps virus.

La submaxilitis aguda bilateral es un evento raro, salvo cuando está causada por sialolitiasis. Se la ha descrito secundaria a procesos alérgicos, infecciosos, supurativos, virales o autoinmunes como el síndrome de Sjögren; a la administración de fármacos como tiopurinas, nitrofurantoina, fenilbutazona, captopril, y tras procedimientos sobre la vía aérea superior, como endoscopia digestiva alta, broncoscopia, intubación orotraqueal y colangiopancreatografía retrógrada endoscópica por coledocolitiasis (CPRE). El tratamiento con fármacos antagonistas del factor de necrosis tumoral alfa (TNF-alfa) se asocia con riesgo acentuado de reactivación de infecciones bacterianas intracelulares, de forma que se ha descrito la listeriosis en afecciones que requieren dicho tratamiento, como enfermedades reumáticas, dermatológicas y del intestino en sujetos que presentaban otras comorbilidades o estaban inmunocomprometidos. La listeriosis provoca bacteriemia y meningitis predominantemente, cuando es sintomática, e infecta a los sujetos inmunodeprimidos, en los que, a pesar de la antibioticoterapia, tiene una letalidad del 30%. Se presenta el caso clínico de un paciente varón, inmunodeprimido, secundario a tratamiento por azatioprina y prednisona seguido de adalimumab, por enfermedad inflamatoria intestinal indeterminada, sobreinfectada por citomegalovirus, que tras la ingesta de carne contaminada por Listeria monocytogenes, sufrió un cuadro de bacteriemia por listeriosis que mejoró con tratamiento con antibióticos, seguido de submaxilitis aguda bilateral transitoria, que cedió con tratamiento sintomático (hidratación oral). Es el único caso descrito en la literatura en el que un paciente inmunodeprimido tratado con adalimumab presenta submaxilitis aguda bilateral en el contexto de la listeriosis, provocada por el virus de la parotiditis.

Infección por listeria monocytogenes en el embarazo, asociado a desprendimiento de placenta y complicaciones perinatales: reporte de un caso / Listeria monocytogenes infection in pregnancy, associated with placental abruption and perinatal complications: case report

INTRODUCCIÓN la listeriosis, aunque es una infección infrecuente, debe ser considerada en pacientes inmunocomprometidos y gestantes, especialmente en aquellos que consumen alimentos crudos o productos lácteos no pasteurizados, lo que pone en riesgo a un gran número de mujeres embarazadas en países de habla hispana. Es importante que el médico considere su inclusión en los posibles diagnósticos diferenciales cuando la sospecha clínica lo amerite, lo que permitirá hacer un diagnóstico temprano y por lo tanto un tratamiento oportuno, evitando así las posibles complicaciones en el binomio madre-hijo. CASO CLÍNICO clínico multigestante, con embarazo de 33 + 5 semanas, que ingresó a una institución de alto nivel de complejidad en la ciudad de Medellín, Colombia, por síndrome febril asociado a sepsis obstétrica debido a infección intraamniótica por Listeria monocytogenes, que requirió cesárea de urgencia, en donde se evidenció un desprendimiento placentario del 100 % secundario al proceso infeccioso y asociado a complicaciones neonatales. CONCLUSIONES: el diagnóstico de listeriosis gestacional supone un reto clínico por su presentación inespecífica y baja incidencia. Sin embargo, las consecuencias obstétricas arrastran una gran morbilidad de la madre y morbi-mortalidad neonatal, lo que hace de suma importancia que el clínico lo tenga presente en su arsenal diagnóstico, ya que una vez diagnosticado, el tratamiento oportuno tiene desenlaces clínicos favorables.

INTRODUCTION: although listeriosis is a rare infection, it should be considered in immunocompromised patients and pregnancy, especially in those who consume raw food or unpasteurized dairy, which puts a large number of pregnant women in Hispanic countries at risk. It is of special importance for physicians to include listeriosis among possible diagnoses when clinical suspicion arises in order to timely treat it and thus avoid the complications that may occur in the mother-child binomial. CLINICAL CASE: a pregnant woman (33 + 5 weeks) with multiple gestations, was admitted to a high level of complexity institution in the city of Medellín, Colombia, presenting a febrile syndrome associated with obstetric sepsis due to intra-amniotic infection by Listeria monocytogenes, which required emergency cesarean section where a 100 % placental abruption was evidenced secondary to the infectious process and associated with neonatal complications. CONCLUSIONS: The diagnosis of gestational listeriosis is a clinical challenge due to its nonspecific presentation and low incidence. However, the obstetric consequences drag a great maternal morbidity and neonatal morbidity and mortality, which is why it is important for physicians to consider this in the diagnostic arsenal because once diagnosed, the appropriate treatment has favorable clinical outcomes.

Listeriose em pacientes nefropatas imunossuprimidos - relato de dois casos / Listeriosis in patients immunosuppressed nephropaths - report of two cases

Contexto: A Listeria monocytogenes é um bacilo gram-positivo de baixa patogenicidade na população geral, mas importante causa de mortalidade por sepse e meningite em pacientes imunocomprometidos. Receptores de órgãos sólidos e candidatos em tratamento de dessensibilização são suscetíveis à infecção pela Listeria monocytogenes, embora sua apresentação clínica seja pouco reconhecida. Descrição dos casos: Paciente do sexo masculino, 43 anos, internado devido a rejeição aguda de enxerto pós-transplante renal, apresenta pico febril matutino e cefaleia. Paciente do sexo feminino, 59 anos, com doença renal crônica e em terapia de dessensibilização devido reatividade a painel antígeno leucocitário humano, busca pronto-socorro com febre, cefaleia e diarreia. A infecção por Listeria monocytogenes foi confirmada por hemocultura em ambos os casos. Discussão: A ocorrência de listeriose é esporádica e associada ao consumo de alimentos altamente contaminados, como laticínios, produtos frescos e carnes processadas. A redução da imunocompetência é o principal fator de risco para o desenvolvimento da doença em não gestantes, bem como para o aumento da mortalidade. O diagnóstico é estabelecido majoritariamente por hemocultura e o exame do líquido cefalorraquidiano é imprescindível para acessar o acometimento do sistema nervoso central, uma vez que os sinais meníngeos podem estar ausentes. O tratamento é realizado com beta-lactâmicos ou aminoglicosídeos. A ampicilina foi utilizada nos casos relatados e promoveu boa resposta clínica. Conclusão: Os profissionais devem atentar para a gravidade da infecção por Listeria monocytogenes e considerar sua ocorrência em pacientes imunocomprometidos, fornecendo orientações profiláticas a todos os candidatos a transplante de órgãos sólidos e tratamento empírico nos casos suspeitos.

Clinical characteristics of patients with listeriosis / 中南大学学报(医学版)

OBJECTIVES@#To investigate the clinical characteristics of patients with listeriosis and to provide a basis for diagnosis, treatment, prevention and control of hospital infection.@*METHODS@#A total of 10 inpatients, who suffered from the listeriosis in Xiangya Hospital, Central South University from January 2013 to June 2019, were retrospectively collected for this study. The characteristics of the patients' age, gander, basic information, case type, clinical manifestations, first consultation department, days of diagnosis, infection indicator, specimen type, results of drug sensitivity, treatment plan, hospital infection or not, outcome, follow-up data were analyzed.@*RESULTS@#Two cases were pregnant women and other were non-pregnant adults among 10 patients with listeriosis. Among them, there were 3 cases with hospital acquired infection. The age of patient onset was 27-71 years old, and the time from onset to diagnosis was 5-36 days. Five cases had fever, and other 5 cases had not fever. There were headache, fatigue, local pain, and other specialized symptoms in the 10 patients.The white blood cell count,the neutrophil ratio, the inflammatory index C-reactive protein, the procalcitonin were all increased, and the erythrocyte sedimentation was accelerated in the 10 patients.All the patients were sensitive to ampicillin, penicillin G, meropenem, and compound sinomine.@*CONCLUSIONS@#Listeriosis often affects the patients with low immunity, which often leads to misdiagnosis or missed diagnosis in clinic.So early prevention, early diagnosis, and early treatment can reduce mortality; it is important for departments of nosocomial infection management to manage patients' diet for avoiding outbreaks of listeriosis in hospital.

Adesão, internalização e sobrevivência de Salmonella spp. e Listeria monocytogenes em mangas (Mangifera indica), variedade 'Tommy Atkins' / Adhesion, internalization and survival of Salmonella spp. and Listeria monocytogenes in mangoes (Mangifera indica), variety 'Tommy Atkins'

Surtos de salmonelose e listeriose associados ao consumo de frutas inteiras ou minimamente processadas ocorrem com frequência. O objetivo deste estudo foi investigar a capacidade de adesão e internalização de Salmonella spp. e Listeria monocytogenes em mangas (Mangifera indica) variedade Tommy Atkins, em diferentes condições de contaminação experimental e tratamento hidrotérmico, bem como avaliar a multiplicação dos patógenos internalizados na polpa das frutas durante armazenamento em refrigeração (8oC ) e temperatura ambiente (25oC). O estudo foi conduzido com as cepas S. Enteritidis ATCC 13076, S. Thyphimurium ATCC 14028, L. monocytogenes ATCC 7644 e L. monocytogenes Scott A. Inicialmente as cepas foram avaliadas segundo o índice de hidrofobicidade e capacidade de formação de biofilme em poliestireno. A adesão à superfície da manga foi avaliada por técnicas microbiológicas e também pela técnica de microscopia eletrônica de varredura. A internalização foi avaliada a partir de inoculação na cicatriz do pedúnculo (6 log UFC/mL) e após tratamento hidrotérmico e imersão em solução contaminada (6 log UFC/mL), mantidas a 8 °C e a 25 °C por 24h, 5 e 10 dias. A sobrevivência foi avaliada através da inoculação em região demarcada, em cenário de baixo (2 log UFC/mL) e alto nível de contaminação (6 log UFC/mL), a 8 °C e 25 °C, nos tempos 0, 1, 2, 3, 5 e 10 dias. A adesão foi observada nos dois patógenos, mesmo após sucessivas lavagens, com diferença significativa (p<0,05) após 1h de exposição e observou-se presença de estruturas exopolissacarídicas em diferentes tempos e condições de temperatura. A internalização ocorreu em todas as amostras avaliadas e a região do pedúnculo foi a mais afetada pela contaminação, diferindo significativamente na comparação com a região blossom end (p<0,05) a 8 °C e 25 °C. A sobrevivência foi observada nas duas temperaturas até o décimo dia. A multiplicação a 8°C foi significativamente mais baixa (p<0,05). Os resultados demonstraram que a Salmonella spp e L. monocytogenes são capazes de aderir à superfície, de internalizar e se alastrar pela polpa e ainda sobreviverem por períodos consideráveis, em 8 °C e 25 °C. Esses dados poderão auxiliar produtores e órgãos de saúde no desenvolvimento de avaliações quantitativas de risco e no estabelecimento de medidas adequadas para evitar surtos

Outbreaks of salmonellosis and listeriosis associated with the consumption of whole or minimally processed fruits occur frequently. The aim of this study was to investigate the ability of spp. and Listeria monocytogenes to adhere and internalize in mangoes (Mangifera indica) variety Tommy Atkins, under different conditions of experimental contamination and hydrothermal treatment, as well as evaluate the multiplication of the internalized pathogens in the fruit pulp during storage under refrigeration (8oC) and room temperature (25oC). The study was conducted with the strains S. Enteritidis ATCC 13076, S. Thyphimurium ATCC 14028, L. monocytogenes ATCC 7644 and L. monocytogenes Scott A. Initially the strains were evaluated according to the hydrophobicity index and capability to form biofilms on polystyrene surface. Adhesion to the mango surface was evaluated by microbiological techniques and also by scanning electron microscopy. Internalization was evaluated by inoculating the peduncle scar (6 log CFU / mL) and immersion of the fruits in contaminated solution (6 log CFU / mL) after hydrothermal treatment, during storage at 8 °C and 25 °C for 24h, 5 and 10 days. Survival was assessed by inoculation in a demarcated region, using low (2 log CFU / mL) and high level of contamination (6 log CFU / mL), and storage at 8 °C and 25 °C during 0, 1, 2, 3, 5 and 10 days. Adhesion was observed for both pathogens, even after successive washes, with a significant difference (p <0.05) after 1 h of exposure. Adhesion was mediated by exopolysaccharide structures, observed at different times and temperature conditions. Internalization occurred in all samples and the peduncle region was the most affected by the contamination, differing significantly in comparison with the blossom end region (p <0.05) at 8 °C and 25 oC. Survival was observed at both temperatures until the tenth day. The multiplication at 8 °C was significantly lower than at 25 oC (p <0.05). The results showed that Salmonella spp and L. monocytogenes were able to adhere to the surface, to internalize and spread through the pulp and still survive for considerable periods, at 8 °C and 25 °C. This data may help producers and health agencies to develop quantitative risk assessments and to establish appropriate measures to prevent outbreaks

Listeria monocytogenes meningoencephalitis in a patient with Systemic Lupus Erythematosus / Meningoencefalite por Listeria monocytogenes em paciente com Lúpus Eritematoso Sistêmico

Abstract Introduction: Infectious complications are common in systemic lupus erythematosus. Although uncommon, central nervous system infections do occur and have significant lethality, with several etiological agents. Methods: We report on the case of a 29-year-old woman recently diagnosed with systemic lupus erythematosus with hematological, cutaneous, serous and renal manifestations (class IV lupus nephritis), who underwent corticosteroid pulse therapy and mycophenolate induction therapy. After 3 months of evolution, she developed headache and altered mental status. Computed tomography showed an area of hypoattenuation in the left frontal white matter and her cerebrospinal fluid examination showed pleocytosis and hyperproteinorrhachia. Peripheral blood and CSF culture identified Listeria monocytogenes. The patient presented deterioration of her neurological status, requiring invasive mechanical ventilation, monitoring of intracranial pressure and, despite all the intensive support, persisted in a comatose state and developed multiple organ failure, evolving to death due to nosocomial bloodstream infection. Discussion: Infection from L. monocytogenes usually occurs after eating contaminated food, manifesting itself with diarrhea and, occasionally, invasively, such as neurolisteriosis. Further investigation with CSF analysis and MRI is necessary, and the diagnosis consists of isolating the bacteria in sterile body fluid. Conclusion: The case presents a patient whose diagnosis of meningoencephalitis became an important differential with neuropsychiatric disorder. The poor outcome reinforces the need to remember this infectious condition as a serious complication in the natural history of SLE.

Resumo Introdução: As complicações infecciosas são frequentes no lúpus eritematoso sistêmico. Apesar de incomum, infecções do sistema nervoso central ocorrem e têm significativa letalidade, apresentando diversos agentes etiológicos. Métodos: Descrevemos aqui o caso de uma mulher de 29 anos recentemente diagnosticada com lúpus eritematoso sistêmico com manifestações hematológica, cutânea, serosa e renal (nefrite lúpica classe IV), submetida a pulsoterapia com corticoide e terapia de indução com micofenolato. Após 3 meses de evolução, apresentou quadro de cefaleia e alteração de estado mental. Tomografia computadorizada evidenciou área de hipoatenuação em substância branca frontal esquerda e exame de líquido cefalorraquidiano mostrava pleocitose e hiperproteinorraquia. Cultura de sangue periférico e do liquor identificaram Listeria monocytogenes. Paciente apresentou deterioração do quadro neurológico, necessitando de ventilação mecânica invasiva, monitorização de pressão intracraniana e, apesar de todo o suporte intensivo, persistiu em estado comatoso e disfunção de múltiplos órgãos, evoluindo a óbito por infecção de corrente sanguínea nosocomial. Discussão: Infecção por L. monocytogenes ocorre geralmente após ingestão de alimentos contaminados, manifestando-se por diarreia e, eventualmente, de forma invasiva como a neurolisteriose. Investigação complementar com análise de liquor e ressonância magnética faz-se necessária, sendo o diagnóstico confirmado por isolamento da bactéria em líquido corporal estéril. Conclusão: O caso representa uma paciente cujo diagnóstico de meningoencefalite tornou-se importante diferencial com atividade de doença neuropsiquiátrica. A evolução insatisfatória reforça a necessidade de se lembrar desta condição infecciosa como complicação grave na história natural do LES.

ISA 61 VG adjuvant enhances protective immune response of Listeria monocytogenes inactivated vaccine / 生物工程学报

Listeria monocytogenes (Lm) is zoonotic pathogen that can cause listeriosis, and vaccine is one of the effective methods to prevent this pathogen infection. In this study, we developed a novel vaccine that is a mixture of inactivated bacteria and Montanide™ ISA 61 VG, a mineral oil adjuvant, and evaluated the safety and immune response characteristics of this vaccine. The mice immunized with the ISA 61 VG adjuvant had high safety, and it could induce significantly higher titer of anti-listeriolysin O (LLO) antibody and higher value of IgG2a/IgG1 ratio compared with the group without the adjuvant. In particular, it could provide 100% immune protection against lethal doses of Lm challenge in mice. In summary, ISA 61VG adjuvant significantly enhanced the ability of inactivated listeria vaccine to induce humoral and cellular immune responses, thereby enhanced the protective immune response in the host, and it is a potential vaccine candidate for the prevention of Lm infection in humans and animals.

Caracterización genética de cepas de Listeria monocytogenes aisladas durante los años 2007-2014 en Chile / Genetic characterization of Listeria monocytogenes strains isolated during 2007-2014 in Chile

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.

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.

Nervous form of listeriosis in buffaloes / Listeriose nervosa em búfalos

ABSTRACT: Listeriosis is a disease that affects several animal species, including humans, and has three different forms of presentation: encephalic, reproductive, or septicemic. The nervous form is caused mainly by the bacterium Listeria monocytogenes. In Brazil, this disease has already been described in sheep, goats, and cattle. There are no reports of the disease in buffaloes in Brazil and worldwide. The objective of this study was to describe an outbreak of listeric meningoencephalitis in buffaloes in the state of Pará, Brazil. The outbreak occurred in a property located in the municipality of Bujaru, in the eastern Amazon, from May to July 2016. In a herd of 47 buffaloes, three animals (Cases 1, 2 and 3), aged <40 days, presented a neurological condition with locomotion difficulty characterized by paralysis of the four limbs, hypoesthesia, lateral recumbency, and death. Morbidity was 6.38% and lethality was 100%. At necropsy, no significant macroscopic lesions were found. Samples of the central nervous system were collected, fixed in 10% buffered formalin, and routinely processed for histopathological analysis. The main microscopic changes observed were unilateral microabscesses in the brainstem composed predominantly of mononuclear cells, with fewer polymorphonuclear cells, and perivascular cuffs composed mostly of mononuclear cells and few neutrophils. Samples of Cases 1 and 2 revealed Gram-positive bacteria in the areas of necrosis by the Gram's stain technique. Samples of Case 1 were positive in immunohistochemistry for L. monocytogenes. Diagnosis of the nervous form of listeriosis was based on epidemiological data, clinical profile, and immunostaining for Listeria monocytogenes. Results showed that listeriosis should be considered in the differential diagnosis in buffaloes with nervous signs.

RESUMO: A listeriose é uma doença que afeta várias espécies animais, incluindo o homem, e possui três formas diferentes de apresentação: nervosa, abortiva ou septicêmica. A forma nervosa é causada principalmente pela bactéria Listeria monocytogenes. No Brasil a doença já foi descrita em bovinos, ovinos e caprinos, mas não foram encontrados relatos desta doença em búfalos no Brasil e no mundo. O objetivo deste trabalho foi descrever um surto de listeriose nervosa em búfalos no estado do Pará, Brasil. O surto ocorreu de maio a julho de 2016, em uma propriedade localizada no município de Bujaru, na Amazônia Oriental. Três bubalinos de um total de 47 animais (Casos 1, 2 e 3), menores de 40 dias, apresentaram um quadro clínico neurológico caracterizado por dificuldade de locomoção, paralisia dos quatro membros, diminuição da sensibilidade cutânea, decúbito lateral e morte. A morbidade foi de 6,38% e a letalidade de 100%. Na necropsia não foram encontradas lesões macroscópicas significativas. Amostras do sistema nervoso central foram coletadas e fixadas em formalina tamponada a 10% e processadas rotineiramente para análise histopatológica. As principais alterações microscópicas observadas foram microabscessos unilaterais no tronco encefálico, compostos predominantemente por células mononucleares, com menor número de polimorfonucleares, e manguitos perivasculares compostos predominantemente por células mononucleares e poucos neutrófilos. Amostras dos Casos 1 e 2 revelaram bactérias Gram positivas nas áreas de necrose na técnica de Gram. Amostras do Caso 1 resultaram positivas na imuno-histoquímica para L. monocytogenes. O diagnóstico da forma nervosa da listeriose foi baseado nos dados epidemiológicos, no quadro clínico patológico e na imunomarcação para Listeria monocytogenes. Os resultados demostram que a listeriose deve ser considerada no diagnóstico diferencial em bubalinos com sinais nervosos.

Phosphorylation residue T175 in RsbR protein is required for efficient induction of sigma B factor and survival of Listeria monocytogenes under acidic stress / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Listeria monocytogenes is an important zoonotic foodborne pathogen that can tolerate a number of environmental stresses. RsbR, an upstream regulator of the sigma B (SigB) factor, is thought to sense environmental challenges and trigger the SigB pathway. In Bacillus subtilis, two phosphorylation sites in RsbR are involved in activating the SigB pathway and a feedback mechanism, respectively. In this study, the role of RsbR in L. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion (ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in the rsbR (RsbR-T175A, RsbR-T209A, and RsbR-T175A-T209A) were constructed to evaluate the roles of these RsbR sequences in listerial growth and survival. SigB was examined at the transcriptional and translational levels. Deletion of rsbR reduced listerial growxth and survival in response to acidic stress. Substitution of the phosphorylation residue RsbR-T175A disabled RsbR complementation, while RsbR-T209A significantly upregulated SigB expression and listerial survival. Our results provide clear evidence that two phosphorylation sites of RsbR are functional in L. monocytogenes under acidic conditions, similar to the situation in B. subtilis.

Should arboviruses be the only diagnosis hypothesis in pregnant women in endemic areas presenting with a rash?

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.

Late stillbirth due to listeriosis

Listeriosis is a sporadic infectious disease, which affects high-risk populations, such as the elderly, pregnant women, newborns, and immunocompromised patients. During pregnancy, listeriosis usually presents like a mild non-specific infection, but it may be responsible for fetal loss, preterm labor, early onset neonatal sepsis, and neonatal death. We report the case of a late stillbirth secondary to maternal chorioamnionitis. Listeria monocytogenes was isolated from the amniotic fluid and the fetal pleural fluid. The fetal autopsy revealed a disseminated inflammatory response with multi-organ involvement. This case illustrates the importance of the prevention and the diagnosis of listeriosis during gestation and may help us to understand the physiopathology of fetal loss due to listeriosis.

Challenging management of chorioamnionitis with placental listeriosis: lessons from 2 cases

Listeriosis is a rare foodborne infection caused by Listeria monocytogenes. It is 12–20 times more prevalent in pregnant women compared to the general population, with a 20–40% mortality rate in neonates. Early treatment with appropriate antimicrobial agents is critical for pregnancy outcomes; however, the infection is difficult to control because the nonspecific clinical manifestations and rarity of the disease often preclude early diagnosis. We encountered 2 cases of pregnancy-associated listeriosis that occurred at 29 and 37 weeks of gestation. Both neonates were delivered by emergent cesarean section due to fetal condition, and one of the preterm infants died immediately after birth. Pregnancy-associated listeriosis should be considered in the management of unexplained fever or inflammatory conditions in pregnant women.

Increasing Incidence of Listeriosis and Infection-associated Clinical Outcomes

BACKGROUND: Listeriosis caused by Listeria monocytogenes has a high case-fatality rate (CFR) of approximately 20% to 30%. An increasing incidence of listeriosis has been reported in many countries recently. We investigated the annual incidence, clinical characteristics, and outcomes of listeriosis at three different hospitals in Korea and evaluated the effects of appropriate empiric antimicrobial treatments on patient outcomes. METHODS: We retrospectively collected the data of all culture-positive cases of human listeriosis from three hospitals of different sizes in Korea during 2006–2016 and calculated the annual number of cases and incidence per 100,000 admissions. RESULTS: A total of 58 patients with L. monocytogenes were included in this study. The incidence of listeriosis was significantly higher in 2013–2016 than in 2006–2012 (RR 3.1; 95% CI 1.79–5.36; P < 0.001), mainly because of an increase in patients over 60 years of age (RR 3.69; 95% CI 1.70–8.02; P < 0.001). Multivariate analysis showed that healthcare-associated infection (adjusted OR, 12.15; 95% CI, 2.56–86.01; P=0.004) and empirical treatment with first-line antimicrobial agents (adjusted OR, 0.08; 95% CI, 0.00–0.63; P=0.044) were associated with CFR. CONCLUSIONS: Healthcare-associated infections caused by L. monocytogenes are associated with high CFR. Adequate initial empirical treatments could reduce CFR, suggesting that careful consideration of an empirical antimicrobial regimen is warranted for elderly or immunocompromised patients admitted to the hospital.

Prevalence and molecular characteristics of Listeria monocytogenes in cooked products and its comparison with isolates from listeriosis cases / 医学前沿

This study aimed to investigate the prevalence and molecular characteristics of Listeria monocytogenes in cooked products in Zigong City, China. The overall occurrence of the L. monocytogenes in the ready-to-eat (RTE) shops and mutton restaurants surveyed was 16.2% (141/873). An occurrence of 13.5% was observed in RTE pork, 6.5% in RTE vegetables, and more than 24.0% in either cooked mutton or cooked haggis. Serotype 1/2b (45.4%), 1/2a (33.3%), and 1/2c (14.2%) were the predominant types. By comparing the clonal complexes (CCs) based on multilocus sequence typing (MLST) of the L. monocytogenes from cooked foods in Zigong City and 33 listeriosis cases from different districts of China, CC87, CC9, CC8, and CC3 were showed to be prevalent in cooked products and CC87 and CC3 were the first two frequent types in the 33 clinic-source strains. All CC87 stains harbored the newly reported Listeria pathogenicity island 4 (LIPI-4) gene fragment ptsA, and all CC3 strains possessed the Listeria pathogenicity island 3 (LIPI-3) gene fragment llsX. These may increase the occurrence of the strains belonging to CC87 and CC3 in listeriosis cases in China and also underline the risk of infection owing to the consumption of the cooked products from Zigong. ST619 (serotype 1/2b) harbored both llsX and ptsA, indicating a potential hypervirulent sequence type in Zigong.

Panorama de la infección por Listeria monocytogenes / Overview of Listeria monocytogenes infection

Resumen La listeriosis es una infección infrecuente pero potencialmente grave, causada por Listeria monocytogenes. La principal vía de transmisión es por el consumo de alimentos contaminados, afecta generalmente a personas mayores, mujeres embarazadas y hospederos inmunosuprimidos, aunque también se ven casos en adultos y niños inmunocompetentes. Listeria monocytogenes es un bacilo grampositivo corto, anaerobio facultativo, no formador de esporas, móvil, que provoca una zona angosta de hemólisis en agar sangre. Es un patógeno intracelular facultativo, por lo que presenta una compleja patogenia. Esta bacteria tiene la habilidad de atravesar la barrera intestinal, la placenta y la barrera hemato-encefálica produciendo cuadros de gastroenteritis, infecciones materno-fetales y meningoencefalitis. Se diagnostica, generalmente, a partir de un cultivo positivo de un sitio estéril. El tratamiento de elección incluye el uso de ampicilina intravenosa sola o en combinación con gentamicina.

Listeriosis is an uncommon but potentially serious infection caused by Listeria monocytogenes. The main route of transmission is through the consumption of contaminated food. It generally affects elderly people, pregnant women and immunosuppressed hosts, although cases are also seen in immunocompetent adults and children. Listeria monocytogenes is a short, anaerobic, non-spore-forming gram-positive bacillus that causes a narrow zone of hemolysis in blood agar. It is a facultative intracellular pathogen, and therefore it shows a complex pathogenesis. This bacterium has the ability to cross the intestinal barrier, the placenta and the blood-brain barrier producing gastroenteritis, maternal-fetal infections and meningoencephalitis. It is most commonly diagnosed from a positive culture of a sterile site. The treatment of choice includes the use of intravenous ampicillin alone or in combination with gentamicin.