Antibiotic treatment for invasive nonpregnancy-associated listeriosis and mortality: a retrospective cohort study

Clinical characteristics of 15 patients with listeria meningitis in adult

Objective

To report and analyze the clinical characteristics of 15 patients with Listeria meningitis in adult.

Methods

We reviewed the medical records of 15 patients with Listeria meningitis who were admitted to Shanxi Bethune Hospital between January 2017 and January 2023.

Results

The clinical manifestations was primarily characterized by fever， altered mental status, headache, neck stiffness, and vomiting. Blood or cerebrospinal fluid (CSF) cultures were performed in 15 cases, and pathogens were detected in 11 of them. Metagenomic next-generation sequencing (mNGS) detected pathogens in 10 cases, with four being negative by conventional methods and six being positive through traditional tests. The laboratory blood results presented leukocytosis. The CSF analysis upon admission showed elevated levels of white blood cells and proteins, as well as decreased chloride and glucose concentration. The brain computed tomography (CT) revealed ventricular enlargement in 3 patients. The brain magnetic resonance imaging (MRI) showed abnormalities in multiple areas of the brain. Despite 3 patients with decompensated hydrocephalus underwent lateral ventricle puncture and drainage，their neurological deterioration were increasingly deteriorating.7 patients were treated by mechanical ventilation due to respiratory insufficiency. After 3 months, there were 9 cases with excellent outcomes（modified Rankin Scale score of 0-2）,2 cases with favorable outcomes（score of 3-5）, and 4 deaths（score of 6）.

Conclusions

This thesis found that the detection rate of Listeria monocytogenes has been on a rise over the past six years in our department, ranking second only to Streptococcus pneumoniae. Additionally, the detection rate achieved by mNGS surpasses that of other conventional methods. Among the patient cohort, 11 had underlying diseases such as systemic lupus erythematosus, tuberculosis, diabetes mellitus, pituitary neoplasms, leukemia and other related illnesses. Once listeriosis is early identified, the adequate antibiotic therapy should be promptly introduced in the course of empirical treatment.

The influence of stress factors on selected phenotypic and genotypic features of Listeria monocytogenes - a pilot study

BACKGROUND

Listeria monocytogenes are Gram-positive rods, widespread in the environment due to their wide tolerance to changing conditions. The apilot study aimed to assess the impact of six various stresses (heat, cold, osmotic, acid, alkali, frozen) on phenotypic features: MIC of antibiotics (penicillin, ampicillin, meropenem, erythromycin, co-trimoxazole; gradient stripes), motility, ability to form a biofilm (crystal violet method) and growth rate (OD and quantitative method), expression level of sigB (stress induced regulator of genes), agrA, agrB (associated with biofilm formation) and lmo2230, lmo0596 (acid and alkali stress) (qPCR) for three strains of L. monocytogenes.

RESULTS

Applied stress conditions contributed to changes in phenotypic features and expression levels of sigB, agrA, agrB, lmo2230 and lmo0596. Stress exposure increased MIC value for penicillin (ATCC 19111 - alkaline stress), ampicillin (472CC - osmotic, acid, alkaline stress), meropenem (strains: 55 C - acid, alkaline, o smotic, frozen stress; 472CC - acid, alkaline stress), erythromycin (strains: 55 C - acid stress; 472CC - acid, alkaline, osmotic stress; ATCC 19111 - osmotic, acid, alkaline, frozen stress), co-trimoxazole (strains: 55 C - acid stress; ATCC 19111 - osmotic, acid, alkaline stress). These changes, however, did not affect antibiotic susceptibility. The strain 472CC (a moderate biofilm former) increased biofilm production after exposure to all stress factors except heat and acid. The ATCC 19111 (a weak producer) formed moderate biofilm under all studied conditions except cold and frozen stress, respectively. The strain 55 C became a strong biofilm producer after exposure to cold and produced a weak biofilm in response to frozen stress. Three tested strains had lower growth rate (compared to the no stress variant) after exposure to heat stress. It has been found that the sigB transcript level increased under alkaline (472CC) stress and the agrB expression increased under cold, osmotic (55 C, 472CC), alkali and frozen (472CC) stress. In contrast, sigB transcript level decreased in response to acid and frozen stress (55 C), lmo2230 transcript level after exposure to acid and alkali stress (ATCC 19111), and lmo0596 transcript level after exposure to acid stress (ATCC 19111).

CONCLUSIONS

Environmental stress changes the ability to form a biofilm and the MIC values of antibiotics and affect the level of expression of selected genes, which may increase the survival and virulence of L. monocytogenes. Further research on a large L. monocytogenes population is needed to assess the molecular mechanism responsible for the correlation of antibiotic resistance, biofilm formation and resistance to stress factors.

Human Listeriosis

Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that can cause severe invasive infections upon ingestion with contaminated food. Clinically, listerial disease, or listeriosis, most often presents as bacteremia, meningitis or meningoencephalitis, and pregnancy-associated infections manifesting as miscarriage or neonatal sepsis. Invasive listeriosis is life-threatening and a main cause of foodborne illness leading to hospital admissions in Western countries. Sources of contamination can be identified through international surveillance systems for foodborne bacteria and strains' genetic data sharing. Large-scale whole genome studies have increased our knowledge on the diversity and evolution of L. monocytogenes, while recent pathophysiological investigations have improved our mechanistic understanding of listeriosis. In this article, we present an overview of human listeriosis with particular focus on relevant features of the causative bacterium, epidemiology, risk groups, pathogenesis, clinical manifestations, and treatment and prevention.

Mortality risk factors related to listeriosis - A meta-analysis

BACKGROUND

Relatively few studies have focused on mortality risk factors for listeriosis in the literature. Information on the mortality of populations with listeriosis is needed. We aimed to explore the mortality risk factors related to listeriosis in this meta-analysis.

METHODS

The studies were considered eligible for inclusion only if they directly compared the mortality risk factors for listeriosis between dead patients and surviving patients. The mortality risk factors included clinical predisposing factors and predisposing comorbidities.

RESULTS

Thirteen studies were included in this study. There were 12,265 listeriosis patients, including 2863 (23.3%) dead patients. The meta-analysis provided evidence that the mortality risk factors related to listeriosis were as follows: 1. Clinical predisposing factors included age ≥ 60 years, primary bacteremia and central nervous system involvement; 2. Predisposing comorbidities included non-hematological malignancies, alcoholism, chronic kidney disease, cardiovascular disease, and pulmonary disease. In addition, autoimmune disease comorbidity had a protective effect against listeriosis.

CONCLUSION

The presence of older patients, primary bacteremia, central nervous system involvement, non-hematological malignancies, alcoholism, chronic kidney disease, cardiovascular disease, and pulmonary disease should alert physicians to the higher risk of mortality.

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.

Antimicrobial Synergy between Aminoglycosides and Licorice Extract in Listeria monocytogenes

Listeria monocytogenes is a foodborne pathogen that can develop serious invasive infections. Among foodborne pathogens, L. monocytogenes exhibits the highest case fatality despite antibiotic treatment, suggesting the current therapy should be improved. Although ampicillin and gentamicin are used as a combination therapy to treat listeriosis, our results showed there is no synergy between the two antibiotics. We discovered that aqueous extract of licorice generated significant antimicrobial synergy when combined with aminoglycosides, such as gentamicin, in L. monocytogenes. In the presence of 1 mg/mL licorice extract, for instance, the minimum inhibitory concentration (MIC) of gentamicin was reduced by 32-fold. Moreover, antimicrobial synergy with licorice extract made gentamicin-resistant clinical isolates of L. monocytogenes susceptible to gentamicin. Given the common use of licorice as a food sweetener in Western countries and a herb in Oriental medicine, our findings suggest that licorice extract can be potentially used as an antibiotic adjuvant to improve the efficacy of antimicrobial treatment of listeriosis.

Bacterial and Viral Infection and Sepsis in Kidney Transplanted Patients

Kidney transplanted patients are a unique population with intrinsic susceptibility to viral and bacterial infections, mainly (but not exclusively) due to continuous immunosuppression. In this setting, infectious episodes remain among the most important causes of death, with different risks according to the degree of immunosuppression, time after transplantation, type of infection, and patient conditions. Prevention, early diagnosis, and appropriate therapy are the goals of infective management, taking into account that some specific characteristics of transplanted patients may cause a delay (the absence of fever or inflammatory symptoms, the negativity of serological tests commonly adopted for the general population, or the atypical anatomical presentation depending on the surgical site and graft implantation). This review considers the recent available findings of the most common viral and bacterial infection in kidney transplanted patients and explores risk factors and outcomes in septic evolution.

The seasonality, steroid use, and lower ratio of neutrophil to lymphocyte associated with bacteremia of Listeria monocytogenes in Japan from 2010 to 2019: a case-control study

BACKGROUND

Despite having a high mortality rate, Asian studies about the characteristics of adult listeriosis are limited. We investigated the incidence of listeriosis per admissions, associated factors, and rate of mortality in listeriosis, compared with non-listeriosis.

METHODS

We recorded the incidence of listeriosis per 10,000 admissions and conducted a case-control study from January 1, 2010, to December 31, 2019, at Tokyo Medical University Hospital (TMUH) in Japan. Cases were defined as adult with listeriosis that was bacteremia due to L. monocytogenes. Controls, defined as adult with non-listeriosis bacteremia due to other pathogens, were matched by age and clinical department to cases. We analyzed differences in seasonality, including warm season (defined as the period from May to October), medication including steroids, laboratory findings, and mortality. The odds ratio and p value between the cases group and control group were calculated using a chi-square test and Fisher's exact test.

RESULTS

The incidence of listeriosis per 10,000 admissions to TMUH was 0.51. Eleven patients, excluding one neonate, were included in the case group. Twenty-six patients, excluding one patient because of contamination and one patient because of insufficient medical record, were included in the control group. Listeriosis onset was associated with the warm season (90.9% vs. 53.8%; p = 0.033), steroid use (54.5% vs. 19.2%; p = 0.042), and a lower ratio of neutrophils to lymphocytes (9.46 vs. 18.44; p = 0.015). The 30-day mortality rate of listeriosis was similar to non-listeriosis (18.3% vs. 19.2%; p = 0.619).

CONCLUSION

The incidence of listeriosis per admissions in this study was similar to that in other Asian countries. Factors associated with listeriosis were the warm season, steroid use, and a lower ratio of neutrophils to lymphocytes. Additionally, the 30-day mortality rate was similarly high in both the listeriosis and non-listeriosis groups.

NF-κB/ROS and ERK pathways regulate NLRP3 inflammasome activation in Listeria monocytogenes infected BV2 microglia cells

Listeria monocytogenes is a food-borne pathogen responsible for neurolisteriosis, which is potentially lethal in immunocompromised individuals. Microglia are the main target cells for L. monocytogenes in central nervous system (CNS). However, the precise mechanisms by which they trigger neuroinflammatory processes remain unknown. The BV2 microglial cell line and a murine model of L. monocytogenes infection were used for experiments in this study. Listeria monocytogenes induced pyroptosis and nucleotide binding and oligomerization, leucine-rich repeat, pyrin domain-containing 3 (NLRP3) inflammasome activation in BV2. Pharmacological inhibition of the NLRP3 inflammasome attenuated L. monocytogenes-induced pyroptosis. Moreover, inhibition of nuclear factor kappa-B (NF-κB) and extracellular regulated protein kinases (ERK) pathways induced a decrease in caspase1 activation and mature IL-1β-17 secretion. Our collective findings support critical involvement of the NLRP3 inflammasome in L. monocytogenes-induced neuroinflammation and, to an extent, ROS production. In addition, ERK and NF-κB signaling play an important role in activation of the NLRP3 inflammasome, both in vitro and in vivo.

Listeriosis Cases and Genetic Diversity of Their L. monocytogenes Isolates in China, 2008-2019

Listeriosis, caused by Listeria monocytogenes, is a severe food-borne infection. The nationwide surveillance in China concerning listeriosis is urgently needed. In the present study, 144 L. monocytogenes isolates were collected from the samples of blood, cerebrospinal fluid (CSF), and fetal membrane/placenta in China for 12 years from 2008 to 2019. We summarized these listeriosis patients’ demographical and clinical features and outcomes. The susceptibility profile for 12 antibiotics was also determined by the broth microdilution method. Multilocus sequence typing (MLST) and serogroups of these listeria isolates were analyzed to designate epidemiological types. We enrolled 144 cases from 29 healthcare centers, including 96 maternal-neonatal infections, 33 cases of bacteremia, 13 cases of neurolisteriosis, and two cutaneous listeriosis. There were 31 (59.6%) fetal loss in 52 pregnant women and four (9.8%) neonatal death in 41 newborns. Among the 48 nonmaternal-neonatal cases, 12.5% (6/48) died, 41.7% (20/48) were female, and 64.6% (31/48) occurred in those with significant comorbidities. By MLST, the strains were distinguished into 23 individual sequence types (STs). The most prevalent ST was ST87 (49 isolates, 34.0%), followed by ST1 (18, 12.5%), ST8 (10, 6.9%), ST619 (9, 6.3%), ST7 (7, 4.9%) and ST3 (7, 4.9%). Furthermore, all L. monocytogenes isolates were uniformly susceptible to penicillin, ampicillin, and meropenem. In summary, our study highlights a high genotypic diversity of L. monocytogenes strains causing clinical listeriosis in China. Furthermore, a high prevalence of ST87 and ST1 in the listeriosis should be noted.

Solid organ donation after death from listeria encephalitis: A case report

Despite organ shortage, organs from donors with listeria infections have been discarded for transplantation. We present the first-reported case of liver transplantation following listeria encephalitis. The patient was admitted with progressing neurological symptoms after an episode of gastroenteritis. Rhombo-encephalitis was diagnosed, and Listeria monocytogenes was found to be the causative pathogen. Despite proper antibiotic treatment and rapid clearance of bacteremia, he continued to deteriorate and became brain dead, after which organ donation was performed. At procurement, he had been treated with amoxicillin for 9 days. The recipient was treated with pipercillin/tazobactam for 21 days. Besides an anastomotic biliary stricture, necessitating endoscopic dilatation and stenting, further clinical course was uneventful and she is doing well eleven months post-transplant. Our case suggests that listeria encephalitis is not an absolute contra-indication to solid organ donation. We suggest that donors should be treated with adequate antibiotics for at least 48h prior to procurement and advocate confirmation of sterile blood cultures as a prerequisite for donation. According to listeriosis guidelines, we suggest that the recipient should be treated with targeted antibiotics for at least 2 weeks. The risk of transmission should, however, always be balanced carefully against the suspected waiting list mortality.