Investigation of a Multistate Outbreak of Listeria monocytogenes Infections Linked to Frozen Vegetables Produced at Individually Quick-Frozen Vegetable Manufacturing Facilities.

In 2016, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and state partners investigated nine Listeria monocytogenes infections linked to frozen vegetables. The investigation began with two environmental L. monocytogenes isolates recovered from Manufacturer A, primarily a processor of frozen onions, that were a match by whole genome sequencing (WGS) to eight clinical isolates and historical onion isolates with limited collection details. Epidemiologic information, product distribution, and laboratory evidence linked suspect food items, including products sourced from Manufacturer B, also a manufacturer of frozen vegetable/fruit products, with an additional illness. The environmental isolates were obtained during investigations at Manufacturers A and B. State and federal partners interviewed ill people, analyzed shopper card data, and collected household and retail samples. Nine ill persons between 2013 and 2016 were reported in four states. Of four ill people with information available, frozen vegetable consumption was reported by three, with shopper cards confirming purchases of Manufacturer B brands. Two identified outbreak strains of L. monocytogenes (Outbreak Strain 1 and Outbreak Strain 2) were a match to environmental isolates from Manufacturer A and/or isolates from frozen vegetables recovered from open and unopened product samples sourced from Manufacturer B; the investigation resulted in extensive voluntary recalls. The close genetic relationship between isolates helped investigators determine the source of the outbreak and take steps to protect public health. This is the first known multistate outbreak of listeriosis in the United States linked to frozen vegetables and highlights the significance of sampling and WGS analyses when there is limited epidemiologic information. Additionally, this investigation emphasizes the need for further research regarding food safety risks associated with frozen foods.

Listeria and enterococcal infections in neonates 28 days of age and younger: is empiric parenteral ampicillin still indicated?

INTRODUCTION: Empiric parenteral ampicillin has traditionally been used to treat listeria and enterococcal serious bacterial infections (SBI) in neonates 28 days of age or younger. Anecdotal experience suggests that these infections are rare. Existing data suggest an increasing resistance to ampicillin. Guidelines advocating the routine use of empiric ampicillin may need to be revisited. OBJECTIVE: This study aimed to describe the epidemiology and ampicillin sensitivity of listeria and enterococcal infections in neonates 28 days of age and younger who presented to 2 pediatric emergency departments (ED) in Michigan. METHODS: We conducted a 2-center, retrospective chart review (2006-2010) of neonates 28 days of age or younger who were evaluated for SBI in the ED. We abstracted and compared relevant demographic, historical and physical details, laboratory test results, and antibiotic sensitivity patterns to ampicillin from the eligible patient records. RESULTS: We identified SBI in 6% (72/1192) of neonates 28 days of age or younger who were evaluated for SBI, of which 0.08% (1/1192) neonates had enterococcal bacteremia and 0.08% (1/1192) neonates had listeria bacteremia. A total of 1.4% (15/1192) of patients had enterococcal urinary tract infection (UTI). Urinalysis is less helpful as a screening tool for enterococcal UTI when compared with Escherichia coli UTI (P < 0.001). Seventy-three percent (11/15) of urine isolates had an increase of minimal inhibitory concentrations, which indicate gradual development of resistance to ampicillin. CONCLUSIONS: Listeria is an uncommon cause of neonatal SBI in febrile neonates who presented to the ED. Empiric use of ampicillin may need to be reconsidered if national data confirm very low listeria and enterococcal prevalence and high ampicillin resistance patterns.

Listeriosis in patients receiving biologic therapies.

The evolution of inflammatory diseases has radically changed since the introduction of biologic therapies, such as tumour necrosis factor alpha inhibitors (anti-TNFα). They, therefore, represent a widely used therapeutic modality. Nevertheless, post-marketing studies reveal an increased risk of infection in patients taking these drugs, especially granulomatous infections such as listeriosis. We aimed to evaluate the reported cases of listeriosis in patients treated with biologic treatments. We used the United States Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) from 2004 to 2011. We also perform a literature review of previously reported cases of listeriosis in patients taking biologic therapies. We identified 266 cases of Listeria monocytogenes infection associated with biologic therapies. The majority of patients were receiving infliximab (77.1 %), followed by etanercept (11.7 %), adalimumab (9.8 %), rituximab (4.1 %), abatacept (0.4 %) and golimumab (0.4 %). Indications for the use of biologics were as follows: 47.7 % for rheumatologic diseases, 38 % for inflammatory bowel diseases, 3.4 % for haematological diseases and 10.5 % for other indications. Seventy-three percent of the patients were receiving concomitant immunosuppressant drugs, especially steroids (56 %) and methotrexate (31.6 %). The median time to the onset of infection was 184 days. Mortality rates range from 11.1 % in adalimumab-treated patients to 27.3 % in rituximab-treated patients (p = 0.7). Listeriosis is common in biologics-treated patients, especially related to infliximab use given concomitantly with other immunosuppressive therapies. Infections after treatment with biologics mostly occurred in the first year after initiating treatment.

Distribución de serotipos de Listeria monocytogenes aislados de alimentos, Colombia, 2000-2009 / Distribution of Listeria monocytogenes serotypes isolated from foods, Colombia, 2000-2009

Introducción. Listeria monocytogenes es un patógeno facultativo intracelular, oportunista, causante de graves infecciones en humanos, como meningitis, encefalitis y bacteriemias; también, es causa de abortos. Los alimentos actúan como medio de transporte para infectar al huésped. La serotipificación ha discriminado trece serotipos: 1/2a,1/2b, 1/2c, 3a, 3b, 3c, 4a, 4ab, 4b, 4c, 4d, 4e, 7. El 4b es causante de la mayoría de listeriosis en el mundo. Objetivo. Determinar la frecuencia en Colombia de los serotipos de L. monocytogenes aislados de alimentos, durante los años 2000-2009. Materiales y métodos. Se trata de un estudio descriptivo y retrospectivo. Se analizaron 1.599 aislamientos, los cuales fueron confirmados como L. monocytogenes y otras especies de Listeria, con pruebas bioquímicas recomendadas por la Food and Drug Administration (Estados unidos) y utilización del sistema bioquímico api Listeria Biomérieux,serotipificadas con la metodología de Seeliger y Höhne. Resultados. De los 1.599 aislamientos, 1.424 fueron confirmados como L. monocytogenes. Los serotipos encontrados fueron: 1/2a con 135 (9,5 %); 1/2b, 154 (10,8 %); 1/2c, 68 (4,8 %); 3a, 4 (0,3 %); 3b, 29 (2,0 %); 3c,2 (0,1 %); 4a, 44 (3,1 %); 4b, 820 (57,6 %); 4c, 6 (0,4 %); 4d- 4e, 140 (9,8 %); 4e, 17 (1,2 %); 7, 2 (0,1 %); y tres no serotipificables, (0,2 %). Los aislamientos procedían principalmente de Bogotá, 1.035 (73 %); de Antioquia, 199 (14 %); de Nariño, 109 (8 %); del Valle del Cauca, 50 (3,5 %), y de otros departamentos, 33 (2,3 %). Conclusión. En los aislamientos analizados, 1.424 (89 %) correspondieron a L. monocytogenes, presentando una buena calidad en el aislamiento e identificación; la mayoría de estos aislamientos pertenecían al serotipo 4b, 820 (57,6 %), serotipo muy virulento. Se recomienda la vigilancia obligatoria de este microorganismo.

Introduction. Listeria monocytogenes is an intracellular, opportunistic pathogen which can cause severe infections such as meningitis, encephalitis and bacteremia. It can also cause abortions in human beings. Foods are the vehicle for infection of the host. Serotypification has discriminated 13 serotypes: 1/2a,1/2b, 1/2c, 3a, 3b, 3c, 4a, 4ab, 4b, 4c, 4d, 4e, 7. 4b is the cause of the majority of cases of listeriosis in the world. Objective. The frequency of serotypes of L. monocytogenes was determined in bacteria isolated from foods in Colombia. Materials and methods. The study is descriptive and retrospective. Over a 10-year period, 2000-2009, 1,599 isolates were examined. All were confirmed as Listeria monocytogenes and other strains of Listeria, using biochemical tests recommended by the Food and Drug Administration (USA) and API Listeria and serotyped using the Seeliger and Höhne method. Results. Of the 1,599 isolates, 1,424 were confirmed as L. monocytogenes. Serotypes identified were: 1/2a, 135 (9.5%); 1/2b, 154 (10.8%); 1/2c, 68 (4.8%); 3a, 4 (0.3%); 3b, 29 (2.0%); 3c, 2 (0.1%); 4a, 44 (3.1%); 4b, 820 (57.6%); 4c, 6 (0.4%); 4d- 4e, 140 (9.8%); 4e, 17 (1.2%); 7, 2 (0.1%); not susceptible of serotypification, three cases, (0.2%). Isolates came mainly from the Capital District of Bogotá, 1,035 (73%); from Antioquia 199 (14%), from Nariño, 109 (8%); from Valle del Cauca 50 (3,5%) and from other provinces 33 (2.3%). Conclusion. Of the analyzed isolates, 1,424 (89%) belonged to L. monocytogenes, showing a good quality in isolation and identification. Most of these isolates belonged to serotype 4b, 820 (57.6%), a highly virulent serotype. Obligatory surveillance of this microorganism is recommended.

Examination of host immune resistance against Listeria monocytogenes infection in cyclophosphamide-treated mice after dietary lipid administration.

BACKGROUND & AIMS: Despite the beneficial effects in the resolution of inflammatory disorders due to their immunosuppressive properties, n-3 polyunsaturated fatty acids are associated with a reduction of immune resistance to some microorganisms. Here, we examine the influence of different dietary lipids on host immune resistance against Listeria monocytogenes in mice treated with cyclophosphamide (CPA). METHODS: Balb/c mice were fed one of four diets, which contained either olive oil (OO), fish oil (FO), hydrogenated coconut oil (HCO) or low fat (LF) for 4 weeks. Subsequently, mice were treated with CPA or PBS, prior to L. monocytogenes infection. Splenocyte proliferation, survival analysis, counts of viable bacteria from spleens and livers, and measurement of pro-inflammatory cytokine levels were determined. RESULTS: The FO-rich diet reduced survival, particularly in CPA-treated mice. CPA was responsible for a significant increase of viable bacteria recovery from spleens and livers within each group fed high fat diets, which was aggravated in mice fed an FO diet. In addition, a significant increase of both TNF-alpha and IL-12p70 levels was detected in this group. These results may acquire a crucial relevance in clinical nutrition, particularly when FO diets are administered to immunocompromised patients. CONCLUSIONS: The mechanism(s) that impair(s) the elimination of L. monocytogenes could be associated with a low mitogen-stimulated splenocyte proliferation, and with an alteration of pro-inflammatory cytokine production. The application of the neutropenic agent CPA moderately aggravates the immunosuppressive state mainly in FO-fed animals.

Listeriosis en el adulto / Listeriosis in the adult

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Reported foodborne illness and gastroenteritis in Australia: annual report of the OzfoodNet network, 2004.

In 2004, OzFoodNet sites recorded 24,313 notifications of eight potentially foodborne diseases, along with 118 outbreaks of foodborne disease. Overall, reports of both notifications and outbreaks were higher than previous years. The most common sporadic diseases were campylobacteriosis (15,640 cases) and salmonellosis (7842 cases). Reports of sporadic cases of Shiga toxin-producing Escherichia coli were rare with only 46 cases, but there were two small clusters due to serotypes O157/O111 and 086. The 118 foodborne disease outbreaks affected 2,076 persons, of whom 5.6 per cent (116/2,076) were hospitalised and two people died. Foods prepared in restaurants and catering settings caused the most outbreaks and the most common agent was Salmonella Typhimurium. Outbreak investigations during 2004 implicated chicken, foods containing eggs, imported oysters and food handlers infected with norovirus. In addition to foodborne outbreaks, OzFoodNet sites reported 874 outbreaks that were spread from person-to-person affecting 25,363 people. Sites conducted 54 investigations into clusters of Salmonella and other pathogens where a source could not be identified. Surveillance of foodborne diseases continued to improve during 2004, with all jurisdictions contributing to national cluster reports and using analytical studies to investigate outbreaks. Ninety-eight per cent of Salmonella notifications on state and territory surveillance databases recorded complete information about serotype and phage type. Foodborne disease may cost Australia as much as 1.2 billion dollars annually making it vital to intervene to prevent disease.

Demonstration of Listeria monocytogenes by immunohistochemistry in formalin-fixed brain tissues from natural cases of ovine and bovine encephalitis.

In the present work, evidence of Listeria monocytogenes antigens based on the avidin-biotin complex (ABC) immunoperoxidase technique was performed on formalin-fixed central nervous system tissues (CNS) from a total of 23 natural cases of encephalitis (four ovine and 19 bovine). Listeria monocytogenes serotype 4 was isolated from 10 of 17 cultured specimens. Meningoencephalitis characterized by focal necrosis, microabscesses, perivascular cuffing, and gliosis with presence of macrophages and/or neutrophils was observed at histological examination. Positive L. monocytogenes antigens were successfully identified by immunohistochemistry (IHC) in the CNS of all 23 cases. Paraffin-embedded tissues assayed were stored up for 17 years. Morbidity of the outbreaks was between 0.3-3% and 0.1-1% for ovine and bovine cases, respectively. In all the ovine cases, flocks involved were under extensive grazing conditions. In nine of the 19 bovine cases (47.3%), supplementation with corn silage was used. The ABC test can help as a practical tool for the diagnosis of natural cases of L. monocytogenes encephalitis on formalin-fixed specimens from ovine and bovine.

[Listeriosis: case report and repetitorium]. / Listeriose: Falldarstellung und Repetitorium.

Three cases of listeriosis are presented: The first patient was a 72-year-old man, who had an operative removal of a thymom one and a half year ago. In 1983 he developed polyradiculitis and was treated with cortison. Three months later he developed meningeal symptoms. In the cerebrospinal fluid 10(5) per ml Listeria monocytogenes could be isolated. Under treatment with chloramphenicol and gentamycin he was cured. The second case was a female 84-year-old patient, who suddenly developed drowsiness and meningism. In the cerebrospinal fluid Listeria in low concentration was isolated. In spite of therapy with penicillin G and gentamycin in high dosage the patient got centralnervous spasms and died on the second day. The third patient was a premature born infant (31. week of pregnancy) with shortness of breath and hydrocephalus, that was treated with ventriculo-peritoneal shunts on both sides. In her fourth month she got a shunt-defect; Listeria in low concentration was isolated out of the cerebrospinal fluid. Treated with gentamycin intrathecal and amoxycillin she was successfully cured. Epidemiology, pathogenesis and new knowledge about diagnosis and therapy of Listeria are presented.