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Listeriosis is a rare but severe disease, mainly caused by Listeria monocytogenes. This study shows the results of the laboratory-based surveillance of Listeriosis in Belgium over the period 1985-2014. Besides the incidence and some demographic data we present also more detailed microbiological and molecular characteristics of human strains isolated since 2000. The strains from the latter period were compared to food and animal strains from the same period. Our study shows that different food matrices were commonly contaminated with L. monocytogenes presenting the same PFGE profile as in patient's isolates. Since 1985, we observed a significant decrease in incidence of the Materno-Neonatal cases (from 0.15 to 0.04 cases /100,000 inhabitants-year), which is probably to be attributed to active prevention campaigns targeting pregnant women. Despite the strengthening of different control measures by the food industry, the incidence of non-Materno-Neonatal listeriosis increased in Belgium (from 0.3 to 0.7 cases /100,000 inhabitants-year), probably due to the rise of highly susceptible patients in an aging population. This significant increase found in non-Materno-Neonatal cases (slope coefficient 7.42%/year, P<0.0001) can be attributed to significant increase in incidence of isolates belonging to serovars 1/2a (n = 393, slope coefficient 6.62%/year, P<0.0001). Although resistance to antimicrobials is rare among L. monocytogenes isolates, a trend to increasing MIC values is evident with chloramphenicol, amoxicillin, tetracycline and ciprofloxacin. We show that fluoroquinolone resistance is not linked to chromosomal mutations, but caused by a variety of efflux pumps. Our study also shows that huge majority of known underlying pathologies (426 out of 785 cases) were cancers (185/426, 43.1%) and haematological malignancies (75/185, 40.5%). Moreover the risk population is susceptible to low levels of contamination in food stressing the need of prevention campaigns specifically targeting these persons., Competing Interests: The authors have declared that no competing interests exist.

The incidence of perinatal and neonatal Listeriosis is underestimated due undiagnosed stillbirths, misdiagnosis of NL and underreporting of single case reports. Recent outbreaks reinforce the need for better surveillance and targeted health education in certain population groups especially during pregnancy.

In September 2015, PulseNet, the national molecular subtyping network for foodborne disease surveillance, identified a cluster of Listeria monocytogenes (Listeria) clinical isolates indistinguishable by two-enzyme pulsed-field gel electrophoresis (PFGE) pattern combination and highly related by whole-genome multilocus sequence typing (wgMLST). A case was defined as isolation of Listeria with the outbreak PFGE pattern and highly related by wgMLST with an isolation date on or after July 5, 2015, the isolate date of the earliest case in this cluster.

Background: The majority of cases of endophthalmitis are caused by exogenous pathogens; only 5-10 % are of endogenous origin. One cause of these rare cases of endogenous endophthalmitis is Listeria monocytogenes. Twenty-six cases of endophthalmitis due to this pathogen have been published over the last twenty years. The aim of this review is to summarize the main risk factors and common clinical findings of endogenous endophthalmitis due to Listeria monocytogenes., Case Presentation: We report on a 62-year-old female presenting with a sterile hypopyon iritis with secondary glaucoma and an underlying rheumatoid disease. In microbiological analysis we identified Listeria monocytogenes. Further we searched through all published cases for typical signs, risk factors, details of medical and surgical treatment and outcome of endogenous endophthalmitis due to this rare pathogen. Ocular symptoms in almost all of these published cases included pain, redness of the eye, and decreased vision. Main clinical features included elevated intraocular pressure and fibrinous anterior chamber reaction, as well as a dark hypopyon. While the infection is typically spread endogenously, neither an exogenous nor endogenous source of infection could be identified in most cases. Immunocompromised patients are at higher risk of being infected than immunocompetent patients. The clinical course of endophthalmitis caused by Listeria monocytogenes had different visual outcomes. In some cases, the infection led to enucleation, blindness, or strong visual loss, whereas most patients showed a tendency of visual improvement during therapy., Conclusion: Early diagnosis and treatment initiation are crucial factors in the outcome of endogenous endophthalmitis caused by Listeria monocytogenes. This possible differential diagnosis should be kept in mind while treating patients with presumable sterile hypopyon and anterior uveitis having a high intraocular pressure. A bacterial source should be considered with a prompt initiation of systemic antibiotic treatment, mainly in immunocompromised patients, who develop endogenous anterior uveitis. An appropriate microbiological sampling is essential to detect atypical microorganisms and to choose an effective antibiotic treatment.

Background: Listeriosis is an opportunistic bacterial infection caused by Listeria monocytogenes and predominantly affects people who are immunocompromised. Due to its severity and the population at risk, prompt clinical diagnosis and treatment of listeriosis is essential. A major step to making a clinical diagnosis is the collection of the appropriate specimen(s) for testing. This study explores factors that may influence the time between onset of illness and collection of specimen in order to inform clinical policy and develop necessary interventions., Methods: Enhanced surveillance data on non-pregnancy associated listeriosis in England and Wales between 2004 and 2013 were collected and analysed. The difference in days between onset of symptoms and collection of specimen was calculated and factors influencing the time difference were identified using a gamma regression model., Results: The median number of days between onset of symptoms and collection of specimen was two days with 27.1 % of cases reporting one day between onset of symptoms and collection of specimen and 18.8 % of cases reporting more than seven days before collection of specimen. The median number of days between onset of symptoms and collection of specimen was shorter for cases infected with Listeria monocytogenes serogroup 1/2b (one day) and cases with an underlying condition (one day) compared with cases infected with serotype 4 (two days) and cases without underlying conditions (two days)., Conclusions: Our study has shown that Listeria monocytogenes serotype and the presence of an underlying condition may influence the time between onset of symptoms and collection of specimen.

Because of its high fatality rate, listeriosis ranks among the most important infectious diseases worldwide. Although ruminants are known as natural reservoirs for Listeria monocytogenes and a possible source of human listeriosis, studies of the prevalence and risk factors associated with ruminant listeriosis are limited to some developed countries. Therefore, this report describes the development of a real-time PCR targeting the hly gene for the absolute quantification of L. monocytogenes based on circular and linear DNA standards. Results show that the PCR that uses circular plasmid as a template gave a 2.6-7.89 greater threshold cycle number than did equimolar linear standards. No cross-amplification was observed when bacteria commonly found in bovine and ovine diseases were tested. The PCR achieved good intra and inter-run reproducibility and a detection limit of 6.1 copies of linear plasmid per reaction. This PCR was then applied to 1134 samples taken from 378 Tunisian ruminants. Based on the test sensitivity (90%) and specificity (100%), the true individual animal prevalence of listeriosis was 5.7% in cattle and 10.2% in sheep. In addition, the true herd-level prevalence was 50.1% in cattle and 26.7% in sheep. A multivariable logistic regression analysis at the animal-population level indicated that for cattle, the variables strata and mastitis were important risk factors, whereas for sheep, the variables strata, age and abortion were found to be associated with listeriosis. At the herd level, risk factors for Listeria test-positivity they were: abortion, herd composition and silage storage for cattle, whereas for sheep were: management system, cleaning frequency, silage storage and floor type. Animal hygiene, food quality and sanitary practices on the farm should be applied as strategies to control this pathogen in ruminant herds., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A single free-ranging common brushtail possum (Trichosurus vulpecula) and 2 captive sibling common ringtail possums (Pseudocheirus peregrinus)from a zoological facility in Sydney, Australia, were diagnosed with multisystemic listeriosis. The brushtail was found dead in an animal enclosure while the ringtails presented with signs of cardiovascular collapse and died shortly thereafter. All 3 animals were culture positive forListeria monocytogenesand demonstrated focal suppurative lesions within the brainstem in addition to fulminant disease in other areas of the thorax and/or abdomen. Listeriosis in phalangeriformes species has rarely been reported, and brainstem lesions have not previously been described. It is speculated that access to the brainstem by the organism may have occurred hematogenously or via retrograde migration along cranial nerves. Sources of infection and the possibility of transmission between animals are also discussed., (© The Author(s) 2015.)

Listeriosis and toxoplasmosis are foodborne illnesses that can have long-term consequences when contracted during pregnancy. Listeriosis is implicated in stillbirth, preterm labor, newborn sepsis, and meningitis, among other complications. Toxoplasmosis is associated with blindness, cognitive delays, seizures, and hearing loss, among other significant disabilities. Healthcare providers who understand the fundamentals of Listeria and Toxoplasma infection will have the tools to identify symptoms and high-risk behaviors, educate women to make safer decisions, and provide anticipatory guidance if a pregnant woman would become infected with either of these foodborne illnesses.

We present a unique case of listeria-infected pseudoaneurysm of the superficial femoral artery. Listeria monocytogenes, a gram positive, intracellular bacterium, is widespread in the environment. The manifestation of infection in humans ranges from mild gastroenteritis to life-threatening listeriosis. The incidence in the healthy population is low (0.7 per 100,000) but rises sharply in pregnancy, the immunocompromised and patients with malignancy. Listeria rarely causes mycotic aneurysm formation, with fewer than 40 cases reported in the literature. Further investigation revealed the patient to be diagnosed with a hepatocellular carcinoma. It is likely that the two pathologies were linked. Hence, we would advocate investigation for underlying malignancy in patients presenting with a mycotic aneurysm, particularly those resulting from Listeria infection., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: To better understand the clinical characteristics and predisposing factors in non-pregnant patients with Listeria monocytogenes (Listeria) sepsis., Methods: Clinical data were collected at Peking Union Medical College Hospital between January 2002 and December 2014. A case with non-pregnant Listeria sepsis is defined as a non-pregnant person with clinically compatible illness and from whom Listeria was isolated from his/her blood culture. We define an underlying condition if a patient has been diagnosed of and/or has been treated for a concurrent baseline disease within 1 month prior to the onset of Listeria sepsis., Results: A total of 35 patients were enrolled. The age of all patients was (49.1 ± 17.0) years. The male to female ratio was 2: 3. Most patients were combined with at least 1 underlying condition (33, 94.3%), including 42.9% patients with an autoimmune disease, 34.3% with malignancies. The majority (91.4%) represented an acute onset (<1 week) with median time of 3 days. Clinical manifestations included fever (34/35, 97.1%), central nervous system (CNS) symptoms (17/35, 48.6%), gastrointestinal tract symptoms (13/35, 37.1%). Fourteen patients had undergone lumber puncture and cerebral spinal fluid (CSF) tests, which revealed abnormalities comparable of Listeria meningitis. Listeria was isolated from CSF in 11 of 14 patients (78.6%). There were 34 patients receiving empiric antibiotics including 54.3% cephalosporins which are resistant to Listeria. Twenty five (71.4%) patients were switched to the target antimicrobials according to positive blood culture. Of the 35 patients with Listeria sepsis, 21 (60.0%) recovered or were cured, however the rest (40.0%) had dismal outcome. Six patients died in hospital, 8 critical patients were discharged and died after transferring to local hospitals., Conclusions: Listeria sepsis is commonly associated with non-pregnant patients with compromised immune function. Clinical presentations include acute fever, CNS symptoms and gastrointestinal symptoms etc. Empiric antibiotics covering Listeria should be considered when sepsis is suspected among susceptible hosts.

The aim of this paper is to present a unique case of neck-necrotizing fasciitis caused by Listeria Monocytogenes in a young woman, successfully treated by surgery and IV antibiotic therapy. Necrotizing fasciitis is a rare, rapidly progressing and potentially life-threatening infection that infrequently occurs in the head and neck region. Pathogens involved in necrotizing fasciitis are heterogeneous and include aerobic and anaerobic bacteria. To the best of our knowledge, this is the only case of neck necrotizing fasciitis caused by Listeria Monocytogenes studied in literature so far.

Here, a novel model of loop-mediated isothermal amplification (LAMP), termed multiple inner primers-LAMP (MIP-LAMP), was devised and successfully applied to detect Listeria monocytogenes. A set of 10 specific MIP-LAMP primers, which recognized 14 different regions of target gene, was designed to target a sequence in the hlyA gene. The MIP-LAMP assay efficiently amplified the target element within 35 min at 63 °C and was evaluated for sensitivity and specificity. The templates were specially amplified in the presence of the genomic DNA from L. monocytogenes. The limit of detection (LoD) of MIP-LAMP assay was 62.5 fg/reaction using purified L. monocytogenes DNA. The LoD for DNA isolated from serial dilutions of L. monocytogenes cells in buffer and in milk corresponded to 2.4 CFU and 24 CFU, respectively. The amplified products were analyzed by real-time monitoring of changes in turbidity, and visualized by adding Loop Fluorescent Detection Reagent (FD), or as a ladder-like banding pattern on gel electrophoresis. A total of 48 pork samples were investigated for L. monocytogenes by the novel MIP-LAMP method, and the diagnostic accuracy was shown to be 100% when compared to the culture-biotechnical method. In conclusion, the MIP-LAMP methodology was demonstrated to be a reliable, sensitive and specific tool for rapid detection of L. monocytogenes strains.

Introduction: Central nervous system infections caused by Listeria monocytogenes usually manifest in the form of meningitis or meningoencephalitis, and are more common among immunosuppressed patients. Brainstem encephalitis (rhombencephalitis) is less common and fatal if not recognized and treated early., Case Report: We describe the case of a 40-year-old, immunocompetent male patient, who presented with initial symptoms of high fever and productive cough. Signs of brainstem involvement appeared later. A magnetic resonance imaging of the brain revealed a lesion of inflammatory appearance in the right medulla oblongata, and the cerebrospinal fluid test showed mononuclear pleocytosis. Blood and cerebrospinal fluid cultures were negative. He presented with a significant improvement with the start of ceftriaxone and subsequent association of corticosteroids, until he developed respiratory failure and died. The third blood cultures grew after his death and they were positive for L. monocytogenes. An autopsy was carried out, which showed necrotizing inflammation, with gram-positive bacilli in the brainstem and the cerebellum., Conclusions: A fatal delay in the diagnosis occurred, mainly because of the favorable clinical response to ceftriaxone and corticosteroids. This case reminds us that a febrile clinical presentation with brainstem involvement must generate the suspicion of a Listeria infection, and therefore ampicillin must be a part of the empirical treatment.

Animal studies have shown that Listeria monocytogenes can probably access the brain through a peripheral intraneural route, and it has been suggested that a similar process may occur in humans. However, thus far, its spreading through the central nervous system (CNS) has not been completely elucidated. The authors present a case of multiple L. monocytogenes cerebral abscesses characterized by a pattern of distribution that suggested spread along white matter fiber tracts and reviewed the literature to identify other cases for analysis. They elected to include only those cases with 3 or more cerebral abscesses to make sure that the distribution was not random, but rather followed a pattern. In addition, they included those cases with abscesses in both the brainstem and the cerebral hemispheres, but excluded cases in which abscesses were located solely in the brainstem. Of 77 cases of L. monocytogenes CNS abscesses found in the literature, 17 involved multiple abscesses. Of those, 6 were excluded for lack of imaging and 3 because they involved only the brainstem. Of the 8 remaining cases from the literature, one was a case of bilateral abscesses that did not follow a fiber tract; another was also bilateral, but with lesions appearing to follow fiber tracts on one side; and in the remaining 6, to which the authors added their own case for a total of 7, all the abscesses were located exclusively in the same hemisphere and distributed along white matter fiber tracts. The findings suggest that after entering the CNS, L. monocytogenes travels within the axons, resulting in a characteristic pattern of distribution of multiple abscesses along the white matter fiber tracts in the brain. This report is the first description suggesting intraaxonal CNS spread of L. monocytogenes infection in humans following its entry into the brain. This distinct pattern is clearly seen on imaging and its recognition may be valuable in the diagnosis of listeriosis. This finding may allow for earlier diagnosis, which may improve outcome.

Listeria monocytogenes has been reported to cause various infectious diseases in both humans and animals. More rarely, ocular infections have been reported. To our knowledge, only two cases of Listeria keratitis have been described in horses. We report kerato-conjunctivitis in four Norwegian horses associated with L. monocytogenes. Clinically, all cases were presented with recurrent unilateral kerato-conjunctivitis. L. monocytogenes bacteria were isolated from swab samples from all cases, and cytology carried out in 3 cases was indicative of L. monocytogenes infection. The present report describes the first known cases in which L. monocytogenes has been isolated from keratitic lesions in horses in Norway. A potential risk factor may be feeding of silage or haylage, but other sources of infection cannot be ruled out. The phenotypic features including antimicrobial susceptibility and serotype of the isolates are described. Laboratory detection of L. monocytogenes demands extra caution since only low numbers of bacteria were detected in the eye-swabs, probably due to the low volume of sample material and the intracellular niche of the bacterium. A general poor response to treatment in all these cases indicates that clinicians should pay extra attention to intensity and duration of treatment if L. monocytogenes is identified in connection with equine kerato-conjunctivitis.

Three multiplex PCR assays were developed to identify the 11 most common Listeria monocytogenes clones in clinical and food samples; 270 (95.7%) of 282 strains of serogroups IVb, IIb, IIa, and IIc were identified accurately. This novel tool is a rapid and efficient alternative to multilocus sequence typing for identification of L. monocytogenes clones., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Brainstem involvement is a characteristic feature and accounts for the high mortality associated with listeriosis especially in immunosuppressed patients. We report two cases of rhombencephalitis infection by Listeria monocytogenes in a 65 and 63-year-old men with diabetes. They were referred to a neurologist due to fever and drowsiness after 3 weeks. The 65-year-old man had vertigo, diplopia, ataxia, bidirectional nystagmus and the 63-year-old man complained of perioral numbness, dysphagia and dysartheria. Treatment with ampicillin (12 g/day) was started empirically and modified when the culture results were available. The CSF cultures were positive to Listeria monocytogenes and brain MRI findings were suggestive of rhomboencephalitis. Despite delays in treatment, they had a complete clinical recovery with resolution of MRI abnormalities. In contrast to our results, in most reports, a bi-phasic illness has 
been described and late treatment was associated with unfavorable courses or long lasting sequelae.

Objective: To summarize the clinical characteristics and outcome of maternal listeriosis so as to improve the understanding of disease and the level of diagnosis and treatment., Methods: Retrospectively, 16 cases of maternal listeriosis, who were treated at Peking Union Medical College Hospital between March 2007 and December 2014 were reviewed. Maternal listeriosis is defined when a pregnant woman presents with symptoms as listeriosis, meanwhile Listeria monocytogenes is isolated from sterile tissue or peripheral blood, or from a non-sterile site (uterus swab) or pathological evidence of chorioamnionitis. The neonatal listeriosis is diagnosed as acute listeria sepsis., Results: The mean age of these 16 patients was (30.0 ± 3.9) years old. There were 1, 8, 7 patients with listeriosis diagnosed in the first, second and third trimester of pregnancy, respectively. All had an acute onset of illness (≤ 2 weeks), the median time from onset to presentation was 2.5 days. Clinical manifestations included fever (93.8%, 15/16), leukocytosis (78.6%, 11/14), chorioamnionitis (77.8%, 7/9), gastrointestinal symptoms (37.5%, 6/16) and fetal movement decrease (31.3%, 5/16). Listeria monocytogenes were isolated from blood (6 cases), uterus swab (6 cases), blood plus uterus swab (1 case), and neonates (3 cases). All maternal cases recovered well after the termination of pregnancy, even none of them had received empiric antibiotics sensitive to listeria. A very high proportion of adverse pregnancy outcomes occurred (15/16, 93.8%). There were 8 fetal losses. Seven neonates were complicated with listeria sepsis and treated successfully., Conclusions: The patients with maternal listeriosis commonly presented with acute fever and an extremely high incidence of adverse pregnancy outcomes, however empiric antibiotics can hardly cover this pathogenic bacterium. So both pregnant women and clinicians should maintain a high level of vigilance against listeriosis and pay more attention to dietetic hygiene.

Although the disease burden of listeriosis on population level is low, on individual level the impact is high, largely due to severe illness and a high case fatality. Identification of risk factors supports and specifies public health actions needed for prevention. We performed a case–control study to determine host- and food-related risk factors for non-perinatal listeriosis in the Netherlands. Patients with non-perinatal listeriosis reported between July 2008 and December 2013 were compared with controls from a periodic control survey who completed a questionnaire in the same period. Higher age, male sex, underlying disease, especially cancer and kidney disease, and use of immunosuppressive medicine were strong risk factors for acquiring non-perinatal listeriosis. Analysis of the food consumption in the group of cases and controls with underlying diseases did not reveal any high-risk food products. Information and advice should continue to be given to persons at risk of severe listeriosis. Univariate analyses indicate that patients using gastric acid inhibitors are at risk. It is worth adding these patients to the group of susceptible persons.

As a major human pathogen in the Listeria genus, Listeria monocytogenes causes the bacterial disease listeriosis, which is a serious infection caused by eating food contaminated with the bacteria. We have developed an aptamer-based sandwich assay (ABSA) platform that demonstrates a promising potential for use in pathogen detection using aptamers as analytical bioconjugates. The whole-bacteria SELEX (WB-SELEX) strategy was adopted to generate aptamers with high affinity and specificity against live L. monocytogenes. Of the 35 aptamer candidates tested, LMCA2 and LMCA26 reacted to L. monocytogenes with high binding, and were consequently chosen as sensing probes. The ABSA platform can significantly enhance the sensitivity by employing a very specific aptamer pair for the sandwich complex. The ABSA platform exhibited a linear response over a wide concentration range of L. monocytogenes from 20 to 2×10(6) CFU per mL and was closely correlated with the following relationship: y=9533.3x+1542.3 (R(2)=0.99). Our proposed ABSA platform also provided excellent specificity for the tests to distinguish L. monocytogenes from other Listeria species and other bacterial genera (3 Listeria spp., 4 Salmonella spp., 2 Vibrio spp., 3 Escherichia coli and 3 Shigella spp.). Improvements in the sensitivity and specificity have not only facilitated the reliable detection of L. monocytogenes at extremely low concentrations, but also allowed for the development of a 96-well plate-based routine assay platform for multivalent diagnostics., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Aim of Study: Authors in their text are bringing the latest published findings on the impact of some of the most common infectious diseases on the course and outcome of pregnancies., Type of Study: Review., Results: Proposals and recommendations for examination, treatment, and management of infected pregnant womans, especially from the view of a primary contact gynecologist.

Listeria monocytogenes is an infrequent cause of bacterial myocarditis. Myocarditis without evidence of endocarditis is even rarer. Management in such cases involves early diagnosis, antibiotic therapy, and emergency treatment of arrhythmias. We report the case of a 47-year-old man who presented with features of acute ST-segment-elevation myocardial infarction complicated by ventricular tachycardia that necessitated urgent electrical cardioversion. Contrast-enhanced cardiac magnetic resonance images revealed hypertrophy, necrosis, and a mass that was determined to be an abscess caused by L. monocytogenes. Antibiotic treatment led to resolution of the listerial myocarditis. In addition to reporting our patient's case, we discuss the comparative advantages of cardiac magnetic resonance versus transthoracic echocardiography in characterizing myocarditis, upon presentation and in follow-up evaluation.

The 63 pulsed-field gel electrophoresis (PFGE) types identified among 427 clinical isolates of Listeria monocytogenes that were characterized in a previous study by serotyping and PFGE (AscI) could be further divided into 17 PFGE groups. While the 63 PFGE types, all part of lineage I, were established based on the number and distribution of all bands in each DNA profile, the 17 PFGE groups were based on the configuration of small bands with sizes <145.5 kb. The 30 PFGE types of L. monocytogenes serovar 4b isolates (n=334) were divided into 8 PFGE groups; the 32 PFGE types of serovar 1/2b isolates (n=90) and the serovar 3b isolates (n=3, 1 PFGE type) were divided into 9 PFGE groups. An association was observed between PFGE groups and serovars. L. monocytogenes isolates belonging to PFGE groups I, J, Q, R, X, Z, Ö-4, and Ö-5 all shared serovar 4b, whereas isolates from PFGE groups D, G, O, P, T, U, Ö-1, Ö-2, and Ö-3 shared serovar 1/2b. Small fragments <33.3 kb were nonvisible in all L. monocytogenes isolates. From the results of the present study, a procedure for accelerating the identification of PFGE types when analyzing new PFGE profiles can be suggested. Therefore, we propose a stepwise procedure to PFGE profiling by first identifying the PFGE group using the smaller band patterns <145.5 kb, and then determining PFGE types based on the band patterns >145.5 kb.

We present a case of colovesical fistula presenting with a clinical syndrome of urosepsis subsequently demonstrated to be due to Listeria monocytogenes bacteraemia. The patient had a history of previous rectal cancer with a low anterior resection and a covering ileostomy that had been reversed 6 months prior to this presentation. L. monocytogenes was also isolated among mixed enteric organisms on urine culture. There were no symptoms or signs of acute gastrointestinal listeriosis or meningoencephalitis. This unusual scenario prompted concern regarding the possibility of communication between bowel and bladder, which was subsequently confirmed with CT and a contrast enema. The patient recovered well with intravenous amoxicillin and to date has declined surgical management of his colovesical fistula. This case illustrates the importance of considering bowel pathology when enteric organisms such as Listeria are isolated from unusual sites., (2015 BMJ Publishing Group Ltd.)

Spontaneous bacterial peritonitis (SBP) is a frequent and potentially deadly complication of ascites in patients with end-stage liver disease. Unlike other pathogens more commonly implicated in SBP, Listeria monocytogenes is a nonenteric organism that maybe acquired either sporadically or in the setting of foodborne outbreaks. Listeria is an unusual cause of SBP that presents particular management challenges because of the organism's intrinsic resistance to first-line and empiric SBP treatment that would otherwise include third-generation cephalosporins. We present here a case of Listeria SBP in a 68-year-old man with previously unidentified cirrhosis. His infection occurred in the context of a nationwide fruit recall for Listeria contamination, prompting an epidemiologic investigation. After describing the case, we then review the extant literature on Listeria peritonitis. To date, no case studies on Listeria SBP have systematically described risk factors for Listeria acquisition. As incidence of Listeria SBP is increasing, however, knowledge of patient risk factors, especially foodborne exposure risks, may be important in preventing future episodes of Listeria SBP, and in accurately monitoring foodborne outbreaks.

Listeriosis patient isolates in Germany have shown a new identical pulsed-field gel electrophoresis (PFGE) pattern since 2012 (n = 66). Almost all isolates (Listeria monocytogenes serotype 1/2a) belonged to cases living in southern Germany, indicating an outbreak with a so far unknown source. Case numbers in 2015 are high (n = 28). No outbreak cases outside Germany have been reported. Next generation sequencing revealed the unique cluster type CT1248 and confirmed the outbreak. Investigations into the source are ongoing.

Listerial brainstem encephalitis (LBE) is an uncommon form of listerial central nervous system infection that progresses rapidly and is invariably fatal unless detected and treated early. We report on six adult patients with LBE, of whom five were managed or co-managed by our unit during the period January - June 2012. All presented with a short prodromal illness followed by a combination of brainstem signs, including multiple cranial nerve palsies with emphasis on the lower cranial nerves, ataxia, motor and sensory long-tract signs, a depressed level of consciousness and apnoea. In two cases the diagnosis was delayed with adverse outcomes. LBE may be difficult to diagnose: clinicians may not be aware of this condition, the brainstem location may not be recognised readily, general markers of inflammation such as the erythrocyte sedimentation rate, C-reactive protein level or white cell count may be normal, and the cerebrospinal fluid is typically normal or there are only mild and nonspecific findings. Serological tests are unreliable, and diagnosis is achieved through blood cultures, magnetic resonance imaging and clinical recognition.

A loop-mediated isothermal amplification (LAMP) assay for rapid and sensitive detection of the L. ivanovii strains had been developed and evaluated in this study. Oligonucleotide primers specific for L. ivanovii species were designed corresponding to smcL gene sequences. The primers set comprise six primers targeting eight regions on the species-specific gene smcL. The LAMP assay could be completed within 1 h at 64°C in a water bath. Amplification products were directly observed by the Loopamp Fluorescent Detection Reagent (FD) or detected by agarose gel electrophoresis. Moreover, the LAMP reactions were also detected by real-time measurement of turbidity. The exclusivity of 77 non-L. ivanovii and the inclusivity of 17 L. ivanovii were both 100% in the assay. Sensitivity of the LAMP assay was 250 fg DNA and 16 CFU per reaction for detection of L. ivanovii in pure cultures and simulated human stool. The LAMP assay was 10 and 100-fold more sensitive than quantitative PCR (qPCR) and conventional PCR assays,respectively. When applied to human stool samples spiked with low level (8 CFU/0.5 g) of L. ivanovii strains, the new LAMP assay described here achieved positive detection after 6 hours enrichment. In conclusion, the new LAMP assay in this study can be used as a valuable, rapid and sensitive detection tool for the detection of L. ivanovii in field, medical and veterinary laboratories.

Food-borne pathogens have been recognized as a major cause of human infections worldwide. Their identification needs to be simpler, cheaper and more reliable than the traditional methods. Here, we constructed a low-cost paper platform for viable pathogenic bacteria detection with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes. The amplification products were applied to the paper-based platform to perform a visual test using sandwich hybridization assays. When the RNA products migrated along the platform by capillary action, the gold nanoparticles accumulated at the designated area. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from L. monocytogenes could be detected. It could also be used to specifically detect 20 CFU/mL L. monocytogenes from actual samples. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. This method is suitable for point-of-care applications to detect food-borne pathogens, as it can overcome the false-positive results caused by amplifying nonviable L. monocytogenes. Furthermore, the results can be imaged and transformed into a two-dimensional bar code through an Android-based smart phone for further analysis or in-field food safety tracking., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Listeria monocytogenes causes gastroenteritis, meningitis and bacteraemia in immunocompromised, pregnant patients, the elderly as well in immunocompetent patients. Focal infections with this organism are uncommon, especially in sporadic (non-outbreak) setting, require high index of suspicion and are challenging to diagnose. We present 3 cases of Listeria monocytogenes presenting as focal infections to our hospitals, all of which are the first reported cases from Australia., Case Presentation: Three unrelated cases of unique focal infections caused by Listeria monocytogenes are presented. 1) A 73 year old Caucasian lady on immunosuppression for colorectal cancer presented with prosthetic knee joint septic arthritis, 2) An 83 year old Caucasian man presented with prosthetic vascular graft infection and 3) A 60 year old Asian man with perianal abscess. Except for case 1, the other cases had a prolonged duration of symptoms on presentation. Listeria was not thought to be causative organism in any of these cases until microbiological specimens isolated the organism. Matrix Associated Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) assisted in making an earlier diagnosis of the infection in all three cases. All of these patients had Listeria monocytogenes isolated from clinical specimens. They were managed with antibiotics and surgery with favourable outcomes. Public health investigations to determine any dietary association were done, however no intervention was thought to be necessary in any of the cases except provide dietary advice. The first two cases highlight the importance of microbiological sampling in serious infections for definitive antibiotic therapy to be administered., Conclusion: Sporadic focal infections with Listeria occur infrequently and are often not diagnosed till culture results from microbiological specimens become available. Dietary history should be an important aspect of thorough clinical history and food consumption advice is crucial in immunocompromised patients on similar lines as given to pregnant women about listeriosis.

Septic vasculitis is a medium and small-vessel vasculitis caused by direct action of pathogens, associated with bacteremia. It is an uncommon condition; clinical manifestations include purpura, ulcers and vesicles-pustules. Most cases of septic vasculitis are related to meningococcemia. There are no cases reported in medical literature associated to Listeria spp. We report a case of a 71 year-old man who presented sepsis by Listeria monocytogenes, and then evolved with purpuric skin lesions. Skin biopsy revealed a septic vasculitis.

The frequency of Listeria monocytogenes (Lm) infection of the central nervous system is increasing. We report a patient recently treated with chemotherapeutic drugs for pulmonary adenocarcinoma who suddenly developed hemiparesis, was initially diagnosed with stroke, and was then found to be affected by Lm rhombencephalitis accompanied by a brain abscess. Lm meningoencephalitis mimicking ischemic stroke is rare but must be considered, especially in specific patients., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In 2010, a marked increase in listeriosis incidence was observed in Finland. Listeria monocytogenes PFGE profile 96 was responsible for one-fifth of the reported cases and a cluster of PFGE profile 62 was also detected. Investigations revealed two fishery production plants with persistent Listeria contamination. It appears likely that the plants were at least partly responsible for the increase of listeriosis. Epidemiological investigation revealed that 57% (31/54) of cases with underlying immunosuppressive condition or medication reported eating gravad or cold-smoked fish. Two public notices were issued by THL and Evira informing which groups were most at risk from the effects of listeriosis and should therefore be cautious in consuming certain products. Systematic sampling of foods and adequate epidemiological investigation methods are required to identify the sources of Listeria infections. Continuous control measures at fishery production plants producing risk products are essential.

Isolates of Listeria monocytogenes (n = 932) isolated in Sweden during 1958-2010 from human patients with invasive listeriosis were characterized by serotyping and pulsed-field gel electrophoresis (PFGE) (AscI). Of the 932 isolates, 183 different PFGE types were identified, of which 83 were each represented by only one isolate. In all, 483 serovar 1/2a isolates were distributed over 114 PFGE types; 90 serovar 1/2b isolates gave 32 PFGE types; 21 serovar 1/2c isolates gave nine PFGE types; three serovar 3b isolates gave one PFGE type; and, 335 serovar 4b isolates gave 31 PFGE types. During the 1980s in Sweden, several serovar 4b cases were associated with the consumption of European raw soft cheese. However, as cheese-production hygiene has improved, the number of 4b cases has decreased. Since 1996, serovar 1/2a has been the dominant L. monocytogenes serovar in human listeriosis in Sweden. Therefore, based on current serovars and PFGE types, an association between human cases of listeriosis and the consumption of vacuum-packed gravad and cold-smoked salmon is suggested.

We describe a case of an 87-year-old woman with rheumatoid arthritis on etanercept who developed subacute encephalopathy. Magnetic resonance imaging and blood cultures led to the diagnosis of Listeria monocytogenes rhomboencephalitis, which proved to be fatal. Postmortem examination of the brain revealed abscesses with extensive necrosis. Gram stain showed small gram-positive rods in the necrotic tissue and the wall lining the abscesses. While rhomboencephalitis is a rare entity, and clinical recognition may be hampered by immunosuppression such as in this case, early blood cultures, lumbar puncture, and empiric treatment with ampicillin should be initiated in all patients with suspected rhomboencephalitis if suggested by imaging and by a clinical concern for infection.