Antibiotic-associated encephalopathyAuthor Response

Retrospective case-control study on screening risk factors of antibiotic-associated encephalopathy in patients with chronic kidney disease

OBJECTIVE

The renal excretion function of patients with chronic kidney disease (CKD) is reduced, and the nervous system toxic reactions of antibiotics are prone to occur. The purpose of this study is to screen out some risk factors for patients with CKD to suffer from antibiotic-associated encephalopathy (AAE).

DESIGN

A case-control study.

SETTING

A tertiary hospital in China.

PARTICIPANTS

The medical records of patients who were hospitalised for CKD and infectious diseases in our hospital from January 2010 to December 2019. All patients used antibiotics to treat infectious diseases during hospitalisation. All patients were divided into two groups according to whether they developed AAE during hospitalisation. The patients with CKD without AAE were selected as the control group (n=120), and the patients with CKD with AAE were regarded as the AAE group (n=102).

INTERVENTIONS

This study systematically analysed its clinical manifestations, laboratory examinations, prognosis, etc, and summarised the risk factors related to AAE in patients with CKD.

PRIMARY OUTCOME

Screening risk factors of AAE in patients with CKD.

RESULTS

Logistic regression analysis showed that coronary heart disease, as well as abnormal indicators of haemoglobin, albumin, uric acid and blood phosphorus were independent risk factors for patients with CKD with AAE (OR values were 4.137, 0.963, 0.849, 0.996 0.161, respectively, all p<0.05). The case fatality rate (Pearson χ²=7.524, p=0.006), rehospitalisation rate (Pearson χ²=6.187, p=0.013) and treatment costs (t=-8.44, p<0.001) in encephalopathy group are significantly higher than the control group.

CONCLUSIONS

Patients with CKD with AAE will increase the case fatality rate and cause poor prognosis. Coronary heart disease, as well as decreased levels of haemoglobin, albumin, uric acid, and blood phosphorus are independent risk factors for patients with CKD with AAE. Timely intervention of these risk factors may reduce the incidence of AAE and improve the prognosis.

In vitro bactericidal activity of amoxicillin combined with different cephalosporins against endocarditis-associated Enterococcus faecalis clinical isolates

Background

The combination of amoxicillin with cefazolin could be an interesting regimen for the empirical therapy of severe infective endocarditis, but its activity against enterococci is unknown.

Objectives

To evaluate in vitro the bactericidal activity of the combination of amoxicillin with different cephalosporins including cefazolin.

Methods

Combinations of amoxicillin (at MIC×¼) with cefazolin, cefotaxime, ceftriaxone, cefepime, ceftaroline or ceftobiprole (at the mean free plasma concentration) were studied using time–kill experiments for 10 endocarditis-associated Enterococcus faecalis strains and 2 reference strains.

Results

The combinations amoxicillin/cefazolin, amoxicillin/cefotaxime, amoxicillin/ceftriaxone and amoxicillin/cefepime were synergistic at 12 and 24 h against 12/12 strains and amoxicillin/ceftobiprole and amoxicillin/ceftaroline against 10/12 strains. The combination amoxicillin/cefepime was bactericidal at 24 h against 9/12 strains, the combination amoxicillin/cefazolin against 8/12 strains, the combinations amoxicillin/ceftaroline, amoxicillin/cefotaxime and amoxicillin/ceftobiprole against 7/12 strains and the combination amoxicillin/ceftriaxone against 6/12 strains.

Conclusions

The combination amoxicillin/cefazolin is as synergistic and bactericidal in vitro as amoxicillin/cefotaxime or amoxicillin/ceftriaxone against E. faecalis.

Metronidazole-induced encephalopathy in a patient with pyogenic spondylitis: a case report

Background

Metronidazole is an antimicrobial agent commonly used in the treatment of several protozoal and anaerobic infections. Neurotoxicity associated with metronidazole has been rarely reported, and the incidence of metronidazole-induced encephalopathy is unknown. Therefore, the accurate diagnosis of metronidazole-induced encephalopathy is often difficult because of the rarity of the disease.

Case presentation

An 86-year-old woman suffered from pyogenic spondylitis of the lumbar spine. Parvimonas micra, a gram-positive anaerobic bacterial species and a resident of the flora of the oral cavity, was identified in the biopsy specimens. Oral administration of metronidazole (1500 mg/day) was initiated. Forty-four days after initiating metronidazole (total intake of 66 g), she complained of tingling sensations in the upper limbs. After 4 days, she complained of additional symptoms including sensory disturbance of the tongue, dysarthria, and deglutition disorder. Characteristic brain magnetic resonance imaging findings on T2-weighted fluid-attenuated inversion recovery and diffusion-weighted imaging led to the diagnosis of metronidazole-induced encephalopathy. Metronidazole was discontinued, and her neurological symptoms improved 10 days after discontinuation. At 14 days after discontinuation of oral metronidazole, abnormal findings on diffusion-weighted imaging almost disappeared.

Conclusions

With the possibility of needing to prescribe metronidazole in the orthopedic field for the treatment of various infections, orthopedic surgeons are likely to encounter cases of metronidazole-induced encephalopathy. Thus, they should be able to recognize the condition and its potential complications. With increased awareness, early diagnosis with magnetic resonance imaging and discontinuation of metronidazole may become feasible when such patients are referred. Our report presents a detailed account of such a case, which may help in the early diagnosis and treatment of patients with metronidazole-induced encephalopathy. Furthermore, we recommend that patients treated with metronidazole should undergo careful and constant surveillance after starting antibiotic therapy.

Neurobehavioral Effects of Cephalosporins: Assessment of Locomotors Activity, Motor and Sensory Development in Zebrafish

Most third- and fourth-generation cephalosporins, such as cefotaxime, cefmenoxime, cefepime, and cefpirome, contain an aminothiazoyl ring at the C-7 position. Drug impurity, which may be produced either during synthesis or upon degradation, can induce adverse effects. Various reports have indicated that neurotoxicity is a side effect of cephalosporin. In this study, we developed methods for assessing the free-swimming activities and behaviors in zebrafish larvae in response to continuous darkness and stimulation of light-to-dark photoperiod transition by chemical treatments. We also performed transcriptome analysis to identify differentially expressed genes (DEGs). Gene ontology analysis revealed that various processes related to nervous system development were significantly enriched by DEGs. We integrated 16 DEGs with protein–protein interaction networks and identified that neuroactive ligand–receptor interaction [e.g., λ-aminobutyric acid and glutamate receptor, metabotropic 1a (GRM1A)] pathway was regulated by the compounds. Our findings suggested that neurobehavioral effects mainly depend on the mother nucleus structure 7-aminocephalosporanic acid and the substitution at the C-3 position. In addition, gad2, or111-4, or126-3, grm1a, opn8c, or111-5, or113-2, and or118-3 may potentially be utilized as novel biomarkers for this class of cephalosporins, which causes neurotoxicity. This study provides neurological behavior, transcriptome, and docking information that could be used in further investigations of the structures and developmental neurotoxicity relationship of chemicals.