Major role of levofloxacin in the treatment of a case of Listeria monocytogenes meningitis

Treatment of Listeria monocytogenes bacteremia with oral levofloxacin in an immunocompromised patient

A 72-year-old woman presented with fever, malaise, and diarrhea. The patient was conscious, and was negative for meningeal signs on physical exam. Blood tests revealed elevated C-reactive protein (CRP) and white blood cell count with neutrophil dominance. Suspecting a bacterial infection, empirical antimicrobial treatment with oral levofloxacin was initiated after collecting two sets of blood culture. On the 3rd day, the patient's fever resolved. On the 7th day, Listeria monocytogenes bacteremia was diagnosed with both blood cultures turning positive. On the 15th day, the patient's symptoms had improved. We ceased treatment when the CRP level decreased. Listeria monocytogenes is a gram-positive bacterium that causes serious infections in elderly and immunocompromised hosts. Penicillin, ampicillin, amoxicillin, and gentamicin are recommended for the treatment of Listeria infections. It has been reported that new fluoroquinolones may be effective in vitro and in animal models. Although further evidence is required, new fluoroquinolones, especially levofloxacin, may provide an option for the treatment of Listeria infection.

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.

Diversity of Listeria monocytogenes Strains of Clinical and Food Chain Origins in Belgium between 1985 and 2014

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.

Implementation of a Meningitis Care Bundle in the Emergency Room Reduces Mortality Associated With Acute Bacterial Meningitis

BACKGROUND

Prompt administration of antibiotics, adjunctive steroid therapy, and optimization of antibiotic delivery to cerebrospinal fluid (CSF) are factors associated with improved outcome of patients hospitalized for acute bacterial meningitis (ABM). However, the impact of a bundle of these procedures has not been reported.

OBJECTIVE

To assess mortality and neurological sequelae at hospital discharge in a cohort of patients with ABM managed according to a predefined bundle.

METHODS

Prospective study of all the patients hospitalized for ABM in two provinces of Northern Italy, over two consecutive periods (2005-2009, 2010-2013). The bundle included: i) supportive care if needed; ii) immediate administration of dexamethasone and 3rd generation cephalosporin; and iii) addition of levofloxacin if turbid CSF. Patients managed according to the bundle were compared with a historical group of patients cared for ABM before the bundle was implemented.

RESULTS

Overall, 85 patients with ABM were managed according to the bundle and were compared with 92 historical controls. In-hospital mortality rates for bundle and control group were 4.7% and 14.1% (p=0.04). Among survivors, 13.5% and 18.9% (p=0.4) of bundle and control-group patients presented neurological sequelae. The only variable associated with mortality at multivariate analysis was ICU admission (HR 3.65). After adjusting for ICU admission, patients managed according with the ABM bundle had significantly lower mortality rate compared to historical controls.

CONCLUSIONS

Use of a bundled protocol and antibiotics with excellent CSF penetration for the initial management of ABM in emergency department is feasible and associated with significant reduction in mortality.

Overexpression of the novel MATE fluoroquinolone efflux pump FepA in Listeria monocytogenes is driven by inactivation of its local repressor FepR

Whereas fluoroquinolone resistance mainly results from target modifications in gram-positive bacteria, it is primarily due to active efflux in Listeria monocytogenes. The aim of this study was to dissect a novel molecular mechanism of fluoroquinolone resistance in this important human pathogen. Isogenic L. monocytogenes clinical isolates BM4715 and BM4716, respectively susceptible and resistant to fluoroquinolones, were studied. MICs of norfloxacin and ciprofloxacin were determined in the presence or in the absence of reserpine (10 mg/L). Strain BM4715 was susceptible to norfloxacin (MIC, 4 mg/L) and ciprofloxacin (MIC, 0.5 mg/L) whereas BM4716 was highly resistant to both drugs (MICs 128 and 32 mg/L, respectively). Reserpine was responsible for a 16-fold decrease in both norfloxacin and ciprofloxacin MICs against BM4716 suggesting efflux associated resistance. Whole-genome sequencing of the strains followed by comparative genomic analysis revealed a single point mutation in the gene for a transcriptional regulator, designated fepR (for fluoroquinolone efflux protein regulator) belonging to the TetR family. The frame-shift mutation was responsible for the introduction of a premature stop codon resulting in an inactive truncated protein. Just downstream from fepR, the structural gene for an efflux pump of the MATE family (named FepA) was identified. Gene expression was quantified by qRT-PCR and demonstrated that fepA expression was more than 64-fold higher in BM4716 than in BM4715. The clean deletion of the fepR gene from BM4715 was responsible for an overexpression of fepA with resistance to norfloxacin and ciprofloxacin, confirming the role of FepR as a local repressor of fepA. In conclusion, we demonstrated that overexpression of the new MATE efflux pump FepA is responsible for fluoroquinolone resistance in L. monocytogenes and secondary to inactivation of the FepR repressor.

Listeria monocytogenes Meningoencephalitis Mimicking Stroke in a Patient with Chronic Lymphocytic Leukemia

INTRODUCTION

Listeria monocytogenes is an important opportunistic pathogen affecting patients with immunosuppression and shows a high tropism for the central nervous system. The clinical manifestations of central nervous system listerial infections are variable and represent a diagnostic challenge.

CASE REPORT

The authors report the case of a 59-year-old woman who was admitted for confusion, agitation, and right-lower extremity weakness. The patient was treated for 3 months with fludarabine and 2 months with corticosteroids for chronic lymphocytic leukemia and hemolytic anemia, respectively. At the time of admission, the neurological examination revealed grade 4 right-lower extremity weakness with reflex asymmetry and right-sided Babinski sign; no signs of meningeal irritation were detectable. Physical examination was notable for grade 1 obesity and subfebrility. The cerebral computed tomography scan demonstrated a hypodense lesion in the left frontal lobe. Cerebral magnetic resonance imaging revealed a hyperintense lesion in the left frontal lobe with extension toward the basal ganglia (T2 and Fluid-Attenuated Inversion Recovery [FLAIR] sequences), and small nodular enhancing lesions after gadolinium infusion in the affected territory. Blood analyses revealed pancytopenia and elevated liver enzymes. During the second day after admission, the patient developed fever and neurological examination revealed signs of meningeal irritation. The cerebrospinal fluid (CSF) analyses revealed: red blood cells 24 cells/mm(3); white blood cells 829 cells/mm(3) (76% lymphocytes, 22% neutrophils, 2% monocytes); protein level 111.2 mg/dL; glucose level 10.2 mg/dL. Empiric anti-infection treatment was started with intravenous ceftriaxone, ciprofloxacine, aciclovir, and fluconasole. Both blood cultures and CSF cultures were positive for L. monocytogenes. The antimicrobial regimen was changed to ampicillin. The clinical and imaging outcome was excellent.

CONCLUSION

The supratentorial focal lesions secondary to Listeria meningoencephalitis are rare. The cases with focal neurological signs without fever at onset can resemble stroke.

[Listeriosis in adults - case reports and review of the literature]

Listeriosis is a rare disease with increasing incidence occurring mainly in elderly people and patients suffering from underlying diseases and immunosuppressive therapy. On the basis of three case reports and a review of the literature the most important aspects of epidemiology, pathogenesis, clinical manifestations, diagnostics and therapy of listeriosis are discussed.

Central nervous system infection with Listeria monocytogenes

The foodborne pathogen Listeria monocytogenes has a particular tropism for the central nervous system and can produce infection in the meninges and brain substance. Well-recognized clinical syndromes include meningitis, brain abscess, rhombencephalitis, and spinal cord abscess; simultaneous infection of the meninges and brain is common. Although it is an uncommon cause of infection in the population at large, L. monocytogenes is an important cause of central nervous system infection in those with impaired cell-mediated immunity, whether due to underlying disease or treatment with immunosuppressive therapeutic agents; it is the etiology in 20% of bacterial meningitis cases in neonates and in 20% of cases in those older than 50 years. Ampicillin is considered the treatment of choice, and trimethoprim-sulfamethoxazole is recommended for those allergic to penicillin. At-risk patients should be advised to avoid unpasteurized milk and soft cheeses along with deli-style, ready-to-eat prepared meats, particularly poultry products.

[Presumptive bacterial meningitis in adults: initial antimicrobial therapy]

CSF sterilization should be obtained very rapidly to reduce both mortality and morbidity due to bacterial meningitis. Thus, antibiotic treatment should be adapted to the suspected bacterium and administered as early as possible at high dosage with - if necessary - a loading dose and continuous perfusion. The rates of abnormal susceptibility to penicillin of Streptococcus pneumoniae, Neisseria meningitis and Haemophilus influenzae are 37%, 30% and 12% respectively. Thus, ceftriaxone or cefotaxim must be used as empirical treatment. Listeria monocytogenes remains fully susceptible to aminopenicillin, so, the combination aminopenicillin and aminoglycoside is the first-line treatment. Antibiotic resistance, allergy or contra-indications, are in fact rare but in these cases, antibiotic combinations are often needed. The latter are more or less complex and clinically validated; they include molecules such as vancomycine, fosfomycin, fluoroquinolone or linezolid.

Management of meningitis due to antibiotic-resistant Acinetobacter species

Acinetobacter meningitis is becoming an increasingly common clinical entity, especially in the postneurosurgical setting, with mortality from this infection exceeding 15%. Infectious Diseases Society of America guidelines for therapy of postneurosurgical meningitis recommend either ceftazidime or cefepime as empirical coverage against Gram-negative pathogens. However, assessment of the pharmacodynamics of these cephalosporins in cerebrospinal fluid suggests that recommended doses will achieve pharmacodynamic targets against fewer than 10% of contemporary acinetobacter isolates. Thus, these antibiotics are poor options for suspected acinetobacter meningitis. From in vitro and pharmacodynamic perspectives, intravenous meropenem plus intraventricular administration of an aminoglycoside may represent a superior, albeit imperfect, regimen for suspected acinetobacter meningitis. For cases of meningitis due to carbapenem-resistant acinetobacter, use of tigecycline is not recommended on pharmacodynamic grounds. The greatest clinical experience rests with use of polymyxins, although an intravenous polymyxin alone is inadvisable. Combination with an intraventricularly administered antibiotic plus removal of infected neurosurgical hardware appears the therapeutic strategy most likely to succeed in this situation. Unfortunately, limited development of new antibiotics plus the growing threat of multidrug-resistant acinetobacter is likely to increase the problems posed by acinetobacter meningitis in the future.

[Antibiotic management of presumptive bacterial meningitis in adults (rational, methods, course, and follow-up)]

The annual incidence of community acquired meningitis ranges between 0.6 and four per 100,000 adults in industrialized countries. The most common causative bacteria are Streptococcus pneumoniae, Neisseria meningitidis, Listeria monocytogenes. The emergence of resistance to antibiotics, especially for S. pneumoniae, could explain the clinical failure of third generation cephalosporins used to treat adults with S. pneumoniae meningitis. The present therapeutic suggestions are more based on the extrapolation of an experimental model than on relevant clinical trials.