Non-perinatal listeriosis: Changes in frequency, clinical spectrum and prognostic factors.

INTRODUCTION: Listeria monocytogenes infection is a severe disease affecting mainly aged people and patients with immune depression. The incidence of listeriosis seems to be increasing. In the present study cases of listeriosis from two hospitals are analyzed with the aims of studying changes in its incidence, clinical forms of presentation and possible factors associated with mortality. METHODS: Retrospective multicentric study of patients with culture-proven listeriosis in two university hospitals in Madrid between 1977 and 2021. Epidemiological and clinical variables, as well as factors for immune depression, complementary studies and treatments were registered. Factors associated with mortality were analyzed. RESULTS: A total of 194 cases of listeriosis were analyzed. The incidence of listeriosis among in-patients increased through the study period, with a significant drop in the number of cases in 2020. The most common clinical presentations were isolated bacteriemia (37.1%) and central nervous system involvement (CNS) (36.6%). Symptoms of gastroenteritis occurred in 21% of cases. Other focal infections were present in 16.5% of patients, the most frequent were spontaneous bacterial peritonitis (8.2%), cholecystitis (2.1%), respiratory infection (1.5%) and vascular prothesis infection (1.5%). In-hospital mortality was 24.7%. Independent factors associated with mortality at admission were age (Odds Ratio [OR] 1.027, 95% confidence interval [IC95%] 1.003-1.056) and a diagnosis of a solid tumor (OR 3.525, IC95% 1.652-7.524). CONCLUSIONS: This study confirms an increasing incidence of listeriosis in our millieu. The most common clinical presentations were isolated bacteriemia and central nervous system involvement. In-hospital mortality was associated with age and the diagnosis of a solid tumor.

Listeria monocytogenes cholangiohepatitis in a lactating Holstein cow.

OBJECTIVE: To describe a unique presentation of systemic Listeria monocytogenes infection in a lactating adult Holstein cow. ANIMAL: 3-year-old second-parity female Holstein, 200 days in milk. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: A 3-year-old Holstein dairy cow was presented for decreased appetite, decreased milk production, and pyrexia. Blood work displayed marked abnormalities in liver-associated parameters. A diagnosis of L monocytogenes cholangiohepatitis was made following liver biopsy, histopathology, and bacterial culture. TREATMENT AND OUTCOME: The cow was treated with systemic antimicrobial and antipyretic therapy. The cow was discharged to continue treatment on farm, and at time of last communication with the owner, the cow was doing very well, with full resolution of clinical signs. CLINICAL RELEVANCE: This case report describes a novel presentation of L monocytogenes infection in an adult bovine. L monocytogenes cholangiohepatitis should be considered a rare differential diagnosis in cattle presenting with evidence of pyrexia and liver disease.

Risk factors associated with early mortality after recovery from severe listeriosis: a multicentre 17-year longitudinal study.

BACKGROUND: Listeriosis presents high rates of mortality but prognostic factors for early prevention are not well established. The aim of this study was to analyse factors associated with in-hospital and early mortality of adults after recovery from severe infection caused by Listeria monocytogenes. METHODS: All cases of listeriosis notified in the province of Granada from January 2005 to December 2021, including 9 centres, were included. Only laboratory confirmed non-neonatal cases were considered. Follow-up was conducted by accessing medical records and epidemiological data. Bivariate and multivariate analyses were conducted to detect potential risk factors associated to in-hospital mortality, 1-year, and 5-year early death after recovery. Multivariate Cox regression models were performed. A total of 206 patients were identified. RESULTS: The mean age was 62.6 years (sd, 18.8). A high frequency of comorbidities (88.3%) was observed, and 42 patients (20.4%) died during hospitalisation. Of the patients who recovered from acute infection, 26 (15.9%) died during the following year and 47 (28.7%) died during the following 5 years. The main factors associated with early mortality after recovery were age (HR: 1.03; 95% CI 1.02-1.07), diabetes mellitus (HR 1.86, 95% CI 1.01-3.44), chronic kidney disease (HR 3.96, 95% CI 1.87-8.38), liver disease (HR 3.62, 95% CI 1.64-8.51), and cancer (HR 3.76, 95% CI 1.90-7.46). CONCLUSION: Listeriosis is associated with high early post-recovery mortality. Our study describes the main prognostic factors, which may help to improve preventive follow-up strategies of adults with severe listeriosis.

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.

Neonatal Listeriosis Presentation and Outcome: A Prospective Study of 189 Cases.

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 (P < .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; P < .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.

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.

Comparison of recombinant and synthetic listeriolysin- O peptide- based indirect ELISA vis-à-vis cultural isolation for detection of listeriosis in caprine and ovine species.

The present study evaluated the comparative serodiagnostic efficacy of recombinant listeriolysin-O (rLLO) and synthetic LLO- 2 peptide-based indirect ELISA vis-à-vis cultural isolation using samples (n = 1326; blood, sera, vaginal swabs, and rectal swabs) collected from caprines (n = 350) and ovines (n = 50) having reproductive and/or nervous system disorders and/or healthy animals. On screening the test sera by rLLO- based ELISA, the antibodies against LLO (ALLO) were observed in 17.71% of the caprines and 2% of the ovines, respectively, while synthetic LLO-2- based ELISA revealed ALLO in 6.86% of caprines and not in ovines. Moreover, the adsorption of positive test sera with streptolysin-O (SLO) resulted in a significant reduction (7.43%; p < 0.05) in the seropositivity with rLLO- based ELISA, whereas LLO-2- based ELISA revealed marginal reduction (4.29%; p > 0.05) in the seropositivity. Overall, the seropositivity with LLO-2 synthetic peptide revealed comparatively less cross-reactivity in comparison to rLLO. The cultural isolation yielded five pathogenic L. monocytogenes isolates and three non-pathogenic Listeria spp. from caprine samples; however, Listeria spp. could not be recovered from any of the ovine samples. Further, on comparing seropositivity with the isolation study results, it was found that two out of the five animals from which pathogenic L. monocytogenes isolated were also found seropositive in both the ELISAs even after adsorption with SLO. Interestingly, rLLO- based ELISA detected antibodies against unadsorbed caprine sera even in those samples from which non-pathogenic Listeria spp. were isolated, whereas antibodies were not detected in LLO-2 peptide-based ELISA. In conclusion, it could be inferred that the synthetic LLO-2 peptide serves as a non- cross-reactive, ideal diagnostic antigen in serodiagnosis of capro-ovine listeriosis.

Favorable Conservative Management of a Rare Primary Aortitis Secondary to Listeria Monocytogenes: Case Report and Review of the Literature.

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

Clinical and molecular epidemiology of human listeriosis in Taiwan.

OBJECTIVE: To determine serogroups, multilocus sequence typing (MLST) of Listeria monocytogenes isolates and analyze clinical characteristics of these clones focusing on non-perinatal cases. METHODS: From 2000 to 2015, we analyzed 123 human listeriosis cases at a medical center in northern Taiwan using PCR serogrouping, MLST, and clinical presentations. RESULTS: The annual incidence of listeriosis increased since 2005 with a peak in 2008 (0.2 per 1000 admission) and decreased thereafter. Of the 115 non-perinatal listeriosis cases, we found a male predominance (60%) with an average age of 63.9 years old (standard deviation: 15.3 years), and almost all patients had underlying conditions including malignancies (61.7%), steroid usage (39.1%), diabetes mellitus (31.3%), renal insufficiency (27.8%), and liver cirrhosis (17.4%). Clinical presentations included bacteremia (74.8%), neurolisteriosis (20.0%), and spontaneous bacterial peritonitis (5.2%). The most frequently identified serogroup-sequence types (ST) were IIB-ST87 (30.9%), followed by IIA-ST378 (16.3%) and IIA-ST155 (14.6%). The 30-day all-cause mortality of non-perinatal listeriosis was 25.2% and was associated with age (Hazard ratio: 1.04, 95% C.I. = 1.01-1.07, p = 0.021), steroid usage (Hazard ratio: 2.54, 95% C.I. = 1.06-6.11, p = 0.038) and respiratory distress at presentation (Hazard ratio: 2.59, 95% C.I. = 1.05-6.39, p = 0.038); while no association was found with serogroups (IIA, IIB, and IVB) or three major ST types by multivariable analysis. All 8 mothers of perinatal listeriosis patients survived and three neonates died (mortality, 37.5%), and IIB-ST87 was the major type (62.5%). CONCLUSION: Predominant strains in Taiwan could cause significant morbidity and mortality. Further disease monitoring and source surveillance are warranted despite a declining trend of human listeriosis in Taiwan.

Systemic Listeria monocytogenes infection and concurrent pleural mesothelioma in a cat.

Herein we describe a rare case of systemic Listeria monocytogenes infection with concurrent pleural mesothelioma in a stray cat that was found dead and submitted for autopsy. Gross pathology changes consisted of thoracic clear yellow fluid admixed with suspended fibrin strands; clear-to-tan, variably sized, <3 mm diameter pulmonary nodules; and enlargement of the submandibular, retropharyngeal, and prescapular lymph nodes. Histologic changes consisted of extensive areas of suppurative inflammation and necrosis with mineralization that partially effaced the pulmonary parenchyma and lymph nodes. Random, distinct necrotic foci were present throughout the hepatic parenchyma. Extending from the pleura, within perinecrotic alveolar spaces, and infiltrating the submandibular, retropharyngeal, and prescapular lymph nodes were dense sheets of neoplastic epithelioid cells with moderate pleomorphism and occasional karyomegaly and multinucleation. Neoplastic cells exhibited immunolabeling for pancytokeratin AE1/AE3 and vimentin, consistent with pleural mesothelioma. Aerobic bacterial culture of lung yielded heavy growth of L. monocytogenes. Immunohistochemistry (IHC) for L. monocytogenes revealed clusters of bacteria in the lung, lymph node, and liver. Pathologic changes were consistent with systemic listeriosis, confirmed by bacterial culture and IHC, and concurrent pleural mesothelioma.

Differences and similarities in clinical manifestations of Listeria monocytogenes and Mycobacterium tuberculous meningitis.

INTRODUCTION: Tuberculous meningitis (TbM) and meningitis caused by Listeria monocytogenes (LM) require different treatment regimens and have grave prognosis if therapy is delayed. THE AIM OF THE STUDY: Comparison of clinical manifestations, laboratory features and outcome of TbM and LM. MATERIAL AND METHODS: We retrospectively analyzed records of 402 patients with community acquired bacterial meningitis (BM) who were hospitalized between January 2010 and September 2019. RESULTS: LM and TbM were diagnosed in 28 (7.0%) and 23 (5.7%) patients, respectively. Patients with TbM were more likely to present with hydrocephalus (p<0.001), scored lower on the Thwaites Index (TI) (p<0.001) and had longer duration of symptoms prior to hospitalization (p=0.001). Furthermore, TbM patients had lower concentration of c-reactive protein (CRP) (p<0.001) and lower white blood cells count (WBC) (p=0.035). When compared to BM patients with etiology other than LM and TbM (nLnTbM), TbM patients presented with lower concentration of CRP (p<0.001), and procalcitonin (PCT) (p<0.001), lower WBC (p<0.001), and lower granulocyte percentage of CSF cytosis (p<0.001), but were more likely to present with hydrocephalus (p<0.001), aphasia (p=0.003) and hemiparesis (p=0.008). In comparison with the nLnTbM group, LM patients had lower concentration of CRP (p=0.01), lower WBC (p<0.001), and lower granulocyte percentage of CSF cytosis (p<0.016). LM patients were also more likely to have concomitant cancer (p=0.008), receive immunosuppressive treatment (p<0.001) or be immunocompromised (p=0.015). CONCLUSIONS: TbM patients had less pronounced inflammation but more severe central nervous system complications compared to patients with LM and other etiologies. Furthermore, LM patients, but not TbM patients, were often immunocompromised.

Listeria spondylodiscitis: an uncommon etiology of a common condition; a case report.

BACKGROUND: Listeriosis is a severe food-borne infection caused by the Gram-positive rod, Listeria monocytogenes. Despite the low incidence (3-8 cases per million), Listeriosis has a case fatality rate of 20-30% as it occurs predominantly in immunocompromised individuals at extremes of age, diabetics and pregnant women. Listeriosis classically presents as a febrile gastroenteritis, isolated bacteremia, meningitis, or maternal-fetal infections. Focal bone and joint infection are rare and primarily involve orthopedic implant devices. Here, we present the first case of Listeria-associated spondylodiscitis. CASE PRESENTATION: A 79-year-old male presents with acute-on-chronic back pain in the absence of risk factors or exposures, aside from age. On radiological imaging, spondylodiscitis of L3-L4 was diagnosed. Subsequently, a CT-guided biopsy was performed to aid in confirming microbiological aetiology. Listeria monocytogenes was grown in culture and patient received appropriate antibacterial therapy. CONCLUSION: The case highlights the utility of image-guided tissue sampling in aiding diagnosis and management in patients with vertebral osteomyelitis. It also encourages consideration of uncommon organisms such as Listeria as an etiology of vertebral osteomyelitis, even in the absence of prosthetic implants.

Listeria monocytogenes septicemia and meningoencephalitis associated with relapsed and refractory follicular lymphoma.

Listeria monocytogenes is a foodborne pathogen which causes life-threatening septicemia and meningoencephalitis. Defective cell-mediated immunity is a well-known risk factor of human listeriosis. We herein present a case of 64-year-old Japanese woman with relapsed and refractory follicular lymphoma (FL). Salvage chemoimmunotherapy with cyclophosphamide, vincristine, prednisolone, and obinutuzumab was followed by obinutuzumab maintenance therapy, when a follow-up computed tomography scan revealed recurrent lymphadenopathy. One month later, the patient presented with fever and headache. L. monocytogenes was recovered from an anaerobic blood culture. Cerebrospinal fluid analysis confirmed the presence of meningoencephalitis. The invasive listeriosis was successfully treated with meropenem for three weeks. There were several predisposing factors of invasive listeriosis in our case. Cell-mediated immunity was severely impaired by prior cytotoxic chemotherapy and low-dose prednisolone. Use of a proton pump inhibitor facilitated entry of the microorganism into the host. Under these circumstances, patients with relapsed and refractory FL are susceptible to invasive listeriosis even if they avoid high-level contaminated food products. Of note, physical examination at initial presentation detected periorbital vesiculopustular eruptions with surrounding erythema. Cutaneous listeriosis is a rare but recurrent manifestation which might be occasionally overlooked. Skin eruptions should be carefully examined for early diagnosis.

Listeria monocytogenes infections: Analysis of 41 patients.

OBJECTIVE: We describe and analyze Listeria-related demographics and clinical features to determine the predisposing conditions for severe infections. METHODS: We performed a retrospective study using positive isolation of Listeria monocytogenes from blood, cerebrospinal fluid, and other organic fluids. Electronic health records were used to determine the epidemiological and clinical features of infections caused by L. monocytogenes. Mortality and sepsis were considered dependent variables in the statistical analyses. RESULTS: We included 41 patients in an observation period of 15 years (2003-2018), with an annual incidence rate of 1.3 cases per 100,000 population. Three main population profiles were identified: newborns, pregnant women, and other adults (17.1%, 12.2%, and 82.9%, respectively). Neuroinvasive infection was present in 17 patients (41.5%). In both univariate and multivariate analyses, neurological infections, whether meningoencephalitis, rhombencephalitis, or brain abscesses, were the main risk factors for severe forms of Listeria-related infections (odds ratio 1.8, 95% CI 1.52-2.14, p=0.01). Malignancies, whether solid tumors or hematological neoplasms, immunosuppression, and chronic diseases were not related to either mortality or severe clinical syndromes. CONCLUSION: Infections caused by L. monocytogenes were uncommon but could cause severe sepsis and mortality, especially in susceptible populations. Our study focused on neurological involvement and severe invasive forms of listeriosis. Neuroinvasive forms were the most important risk factors for severe illness but not for mortality.

Encephalitis caused by Listeria monocytogenes in a healthy adult male in China: A case report.

RATIONALE: Listeria monocytogenes rarely affects immunocompetent adults, and only a few cases of encephalitis caused by L monocytogenes in humans have been reported in China. PATIENT CONCERNS: A 37-year-old male patient presented with headache and fever of 38°C to 39°C for 2 days and dysphoria and dystrophy for 1 day. DIAGNOSIS: The patient was diagnosed as having encephalitis, and his cerebrospinal fluid (CSF) and blood cultures tested positive for L monocytogenes. INTERVENTIONS: The patient was treated with intravenous vancomycin, meropenem, mannitol, methylprednisolone, and enteral nutrition. The computed tomography (CT) scan showed swelling of the brain and hydrocephalus. The patient was treated with emergent surgery, a ventricular drainage tube was inserted, and the CSF was drained daily. OUTCOMES: Despite adequate therapy, the illness was severe and progressed rapidly. The patient died 2 weeks after admission. LESSONS: We report a rare case of L monocytogenes encephalitis in a previously healthy immunocompetent adult in China. The patient's CT scans showed increasing brain swelling and hydrocephalus, and the patient's condition progressively deteriorated.

Listeriosis in Spain based on hospitalisation records, 1997 to 2015: need for greater awareness.

IntroductionListeriosis is a food-borne disease of public health importance that has recently been involved in prolonged outbreaks. Despite its relevance, listeriosis is under-reported in many European countries.AimWe aimed to describe listeriosis epidemiology in Spain from 1997-2015.MethodsWe performed a retrospective study using the Spanish hospitalisation database. We calculated the mean number of hospitalisations per year and region. Pregnancy and neonatal-related listeriosis rates were computed. Relation between death and the presence of underlying health conditions was explored.ResultsBetween 1997-2015, 5,696 listeriosis hospitalisations occurred, showing a constantly increasing trend. Higher hospitalisation rates were located in the north of the country compared to southern regions. The age group ≥ 65 years old was the most represented (50%). Pregnant women and newborns accounted for 7% and 4% of hospitalisations, respectively. An underlying immunocompromising condition was present in 56.4% of patients: cancer (22.8%), diabetes mellitus (16.6%) and chronic liver disease (13.1%). Death occurred in 17% of patients, more frequently among those ≥ 65 years old (67.5%), with sepsis (39.9%) or with meningoencephalitis (19.2%).ConclusionListeriosis is an emergent public health problem in Spain that calls for targeted action. Further prevention strategies are urgently needed, including food safety education and messaging for all at-risk groups.

Vaccine strain Listeria monocytogenes bacteremia occurring 31 months after immunization.

BACKGROUND: Listeria monocytogenes is a food-borne, facultative intracellular bacterium that causes severe diseases such as sepsis and meningoencephalitis in immunocompromised hosts. Because it stimulates robust T-lymphocyte-mediated responses, attenuated L. monocytogenes are candidate vaccine vectors for tumor immunotherapy. CASE: We report a case of bacteremia caused by vaccine strain L. monocytogenes (Axalimogene filolisbac) occurring 31 months after immunization against human papilloma virus (HPV) associated cervical cancer. CONCLUSION: Receipt of a L. monocytogenes-based vaccine is a novel risk factor for delayed L. monocytogenes bacteremia.

Fatal Chemotherapy-induced Combined Infection in a Hodgkin's Disease Patient: a Case Report.

Multimodal therapy, used for the treatment of patients with Hodgkin's disease (HD), makes them prone to life-threatening infections, attributed mainly to febrile neutropenia. Herein, we present a case report of fatal combined bacterial and viral infection in a 49-year-old female patient, subject to polychemotherapy for HD. Rapid microbiological diagnosis performed by multiplex polymerase chain reaction elucidated the causes of the infection within hours. Listeria monocytogenes was detected in both the cerebrospinal fluid and blood samples. Nasopharyngeal swabs returned positive for two swine-derived strains of influenza A virus. We aimed to emphasize the importance of these pathogens and draw attention to their association in the aetiology of infections among patients receiving chemotherapy. In conclusion, better surveillance is needed to improve the early diagnosis of infectious complications in these patients.

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.