Predictors for onset of extended-spectrum beta-lactamase-producing Escherichia coli-induced bacteraemia: a systematic review and meta-analysis

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteraemia can induce unfavourable clinical outcomes due to delay in appropriate antimicrobial treatment and limited therapeutic options. Therefore, elucidating the predictors of ESBL-producing E. coli-induced bacteraemia is crucial to improve clinical outcomes. However, a literature search did not reveal any studies that incorporate a meta-analysis of the predictors of ESBL-producing E. coli-induced bacteraemia. As such, this review was undertaken to assess current evidence on the predictors of ESBL-producing E. coli-induced bacteraemia. PubMed, Web of Science and Cochrane Library databases were searched for all relevant publications from January 2000 to September 2021. This systematic review evaluated 10 observational studies, comprising a total of 2325 patients with E. coli-induced bacteraemia and 850 (36.6%) ESBL-producing strains. In the meta-analysis, previous antibiotic therapy [pooled risk ratio (RR) 2.72; P<0.001], especially with cephalosporins (pooled RR 4.66; P<0.001) and quinolones (pooled RR 5.47; P<0.001), and urinary catheter use (pooled RR 3.79; P<0.001) were predictive of ESBL-producing E. coli-induced bacteraemia. Antibiotic therapy for patients with the above-mentioned risk factors should be selected considering the possibility of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia. It is important to elucidate whether appropriate modulation of the identified risk factors can potentially mitigate the risk of ESBL-producing E. coli-induced bacteraemia compared with non-ESBL-producing E. coli-induced bacteraemia.

Predictors of hypervirulent Klebsiella pneumoniae infections: a systematic review and meta-analysis

BACKGROUND

Hypervirulent Klebsiella pneumoniae (hvKp) infections confer notable morbidity and mortality. Differential diagnosis to determine whether the infections are caused by either the hvKp or classical K. pneumoniae (cKp) strain is particularly important for undertaking optimal clinical care and infection control efforts.

AIM

To identify and assess the potential predictors of hvKp infections.

METHODS

PubMed, Web of Science, and Cochrane Library databases were searched for all relevant publications from January 2000 to March 2022. The search terms included a combination of the following terms: (i) Klebsiella pneumoniae or K. pneumoniae and (ii) hypervirulent or hypervirulence. A meta-analysis of factors for which risk ratio was reported in three or more studies was conducted, and at least one statistically significant association was identified.

FINDINGS

In this systematic review of 11 observational studies, a total of 1392 patients with K. pneumoniae infection and 596 (42.8%) with hvKp strains were evaluated. In the meta-analysis, diabetes mellitus and liver abscess (pooled risk ratio: 2.61 (95% confidence interval: 1.79-3.80) and 9.04 (2.58-31.72), respectively; all P < 0.001) were predictors of hvKp infections.

CONCLUSION

For patients with a history of the abovementioned predictors, prudent management, including the search for multiple sites of infection and/or metastatic spread and the enforcement of an early and appropriate source control procedure, should be initiated in consideration of the potential presence of hvKp. We believe that this research highlights the urgent need for increasing clinical awareness of the management of hvKp infections.

Effects of smoking cessation on endothelial function assessed by flow-mediated dilation and reactive hyperemia peripheral artery tonometry

Background

Smoking predisposes individuals to endothelial dysfunction. Both flow-mediated dilation (FMD) and reactive hyperemia peripheral artery tonometry (RH-PAT) are used to assess endothelial function. However, there are differences in the physiology of vascular beds being tested and in the response of conduit and resistive vessels to RH. Therefore, whether smoking cessation demonstrates comparable effects on endothelial function evaluated by FMD and by RH-PAT remains unclear.

Purpose

We aimed to evaluate the effects of smoking cessation on endothelial function evaluated simultaneously by FMD and RH-PAT.

Methods

Thirty-eight consecutive current smokers (mean±standard deviation; age, 65±10 years) who visited our smoking cessation outpatient department and succeeded in smoking cessation with varenicline were enrolled. Clinical variables, FMD, and natural logarithmic transformation of the reactive hyperemia index (Ln-RHI) were examined before and 20 weeks after treatment initiation. Fifteen current smokers who failed in smoking cessation were enrolled as age- and sex-matched controls. The Spearman's rank correlation coefficient and intraclass correlation coefficient (ICC) for a two-way mixed effects model were performed to assess the agreement of changes in FMD and Ln-RHI. Multivariate logistic regression analysis was performed to examine the associations between the presence of increase in FMD or Ln-RHI and clinical variables.

Results

FMD significantly improved after smoking cessation (3.42%±1.96% to 4.45%±2.28%; p=0.019), whereas Ln-RHI did not (0.53±0.25 to 0.59±0.21; p=0.223). The Spearman's rank correlation coefficient between changes in FMD and Ln-RHI was −0.013, and the ICC was −0.002 (p=0.506). In the multivariate logistic regression analysis, an increase in FMD or Ln-RHI was predicted based on the baseline FMD (odds ratio = 0.54, p=0.013) or Ln-RHI (odds ratio = 0.36, p=0.012), respectively, after adjusting for age and sex.

Conclusions

There was significant improvement in the endothelial function assessed by FMD, but not by Ln-RHI, after smoking cessation. In addition, there was disagreement between changes in FMD and those in Ln-RHI. Smoking cessation may have varying effects on the endothelial function of the conduit and digital vessels.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-aid for scientific research from the ministry of education, science and culture of Japan

[Acute myocarditis with localized left ventricular aneurysm: a report of three cases]

Ventricular aneurysms are rarely observed in viral myocarditis. Three cases whose left ventriculograms showed localized left ventricular aneurysms in the chronic phase of myocarditis are reported. The etiology in one case was herpes simplex virus (Case 1). Two cases (Case 2, 3) of myocarditis were admitted to our Coronary Care Unit in the acute phase, when diffuse hypokinesis of the left ventricle was demonstrated by two-dimensional (2-D) echocardiography. Hypokineses progressed to localized left ventricular aneurysm formation, demonstrated by cine angiography. In the acute phase, ST segment elevation was observed in these two cases, but it resolved. Abnormal Q waves also resolved in the chronic phase. Negative T waves were nearly normalized in one of them (Case 3). Abnormal Q waves with ST segment depression were observed in another case (Case 1). Thus, there were no characteristic or consistent findings suggesting a left ventricular aneurysm on electrocardiography. 2-D echocardiography and cine angiography proved useful for diagnosing this uncommon complication. Long-term follow-up of these cases will be important, because viral myocarditis can develop into dilated cardiomyopathy. The mechanism of left ventricular aneurysm following acute viral myocarditis included: (1) direct viral injury of the myocardium, (2) localized injury due to immunological mechanisms, and (3) coronary thrombosis due to increased platelet aggregation by viral infection.

Improved prognosis after coronary thrombolysis with urokinase in acute myocardial infarction

The effectiveness of coronary thrombolysis with urokinase (UK) on short- and long-term outcome after acute myocardial infarction was studied by comparison of 120 patients treated with UK and 124 with conventional therapy followed up for a period of 20 months. UK was administered to patients within 6 hours of the onset of chest pain, by the intracoronary route (20,000 U/min, at a mean dose of 698,000 U) in 46 patients, intravenously (960,000 to 1,920,000 U in 15 or 30 min, at a mean dose of 1,293,000 U) in 56 patients and by the combined route (at a mean dose of 2,333,000 U) in 18 patients. Complete occlusion or 99% stenosis with severe delay of the contrast medium was found in 72.5% and recanalization by UK was achieved in 68.0%. Cumulative mortality rate was significantly reduced in the UK group (9.2% vs. 29.0%). Cardiac death from recurrent MI was also significantly reduced (2.5% vs. 10.5%). The reduction in mortality rate was demonstrated even in older patients as well as in those cases graded as severe according to the Killip and Forrester classifications. Thus, it is concluded that coronary thrombolysis with UK therapy improves the prognosis of acute myocardial infarction.

Decreased response of plasma catecholamine to stress in diabetic rats

Previously we reported that the heart norepinephrine concentration was markedly increased in diabetic rats. To further study the relationship between a disturbance in the autonomic nervous system and catecholamine metabolism in diabetes mellitus, the plasma catecholamine response to stress and catecholamine concentration of heart and adrenals were measured. Wistar male rats were made diabetic by streptozotocin and kept for 13 weeks. A silicon catheter was placed in the superior V. cava 1 week prior to the experiment. Insulin was injected subcutaneously for 3 days once daily. After an overnight fast and without anesthesia, 1 ml of blood, a control sample, was obtained and then the animals were exsanguinated. The blood was mixed with 1 mM EGTA at a final concentration and centrifuged. The tissue was homogenized with 0.4 N perchloric acid containing 1 mM EGTA and centrifuged at 10,000 x g for 20 minutes. Catecholamines were determined by high performance liquid chromatography. Normal rats responded to blood withdrawal stress, and plasma catecholamines were markedly increased, but almost no increase or an actual decrease was observed in diabetic rats. These abnormal responses were improved by insulin treatment. Heart norepinephrine was increased significantly in the diabetic rats compared with the control rats and was reduced significantly by insulin injections. Adrenal epinephrine was also significantly increased in the diabetic rats compared with the control rats, but was not significantly reduced by insulin. These result suggest a possible disturbance of catecholamine secretion in the diabetic rats.

Increased norepinephrine content in diabetic rat heart

In an attempt to clarify the mechanism of cardiac neuropathy in diabetes mellitus, Wister male rats were made diabetic by streptozotocin injection for 11 to 13 weeks, and catecholamine concentrations of hearts were determined by high performance liquid chromatography. No apparent histological changes were found in hearts and kidneys of any group of rats. Controls used were age-matched normal rats and Goldblatt-hypertensive rats, because streptozotocin induced diabetic rats appeared to be significantly hypertensive. Heart norepinephrine concentrations of diabetic rats and diabetic-Goldblatt-hypertensive rats were markedly higher (8,380 +/- 300 pmol/g tissue and 6,980 +/- 390, respectively) compared with those of controls and Goldblatt-hypertensive rats (2,700 +/- 470 and 2,010 +/- 300, respectively). These results suggest some disturbances in catecholamine secretion in diabetic hearts before typical microangiopathic changes take place.