Bacteraemia due to AmpC β-lactamase-producing Escherichia coli in hospitalized cancer patients: risk factors, antibiotic therapy, and outcomes

The association between methylmalonic acid, a biomarker of mitochondria dysfunction, and phenotypic age acceleration: A population-based study

Phenotypic age acceleration (PAA) is a sensitive marker of biological aging. Circulating methylmalonic acid (MMA) is a novel biomarker of mitochondrial dysfunction and has been associated with age-related disorders. Our study aimed to investigate to what extent circulating MMA was associated with PAA, and whether the association was independent of vitamin B12 status and renal function in the general population. We analyzed cross-sectional data from 13,023 participants across a wide age range (mean age: 38.9 years, range: 12 - 85 years, 51.1% women) from the US National Health and Nutrition Examination Survey (NHANES). PAA was calculated based on the published algorithm. Linear regression models were performed to assess the association between circulating MAA and PAA. Only 31% of the variation in MMA levels was explained by age, sex, race/ethnicity, social economic status, vitamin B12 status, and renal function. Per unit increase in circulating MAA (1.0 nmol/L) was associated with 1.59 years increase in PAA (β = 1.59, 95% CI: 1.17, 2.00, p < 0.001) after adjusting for multiple confounders. Importantly, PAA increased with circulating MMA levels independent of vitamin B12, creatine, and homocysteine levels. The association was more pronounced in subgroups of age ≥ 65 years, women, underweight, vitamin B12 < 400 μmol/L, and homocysteine ≥ 10 μmol/L. The association was much stronger among participants with cardiovascular diseases (CVDs) than without CVDs. In conclusion, our current population-based study showed that mitochondria-derived circulating MMA was associated with increased phenotypic age acceleration in the general population.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models

BACKGROUND

Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches.

METHODS

We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools.

RESULTS

Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported.

CONCLUSIONS

We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

Targeted literature review of the burden of extraintestinal pathogenic Escherichia Coli among elderly patients in Asia Pacific regions

BACKGROUND

Extraintestinal Pathogenic Escherichia coli (ExPEC) is a leading cause of invasive disease, including bacteremia and sepsis. Invasive ExPEC disease (IED) has the potential to complicate the clinical treatment of other conditions and is associated with an increased mortality, hospitalization, and worse outcomes. Older adults and individuals with comorbid conditions are at higher risk of IED. ExPEC is of particular concern in the Asia Pacific region due to aging populations and rising antimicrobial resistance.

OBJECTIVES

This study aimed to synthesize most recent data on the epidemiology, clinical and economic burden of IED in the elderly/high risk populations in China, Japan, South Korea, Taiwan, and Australia.

METHODS

A targeted literature review was conducted using Embase, Medline, as well as local scientific databases. We included studies published in English and local languages published from January 1, 2010 to October 7, 2020 that were relevant to the research objectives. Studies were narratively synthesized.

RESULTS

A total of 1,047 studies were identified and 34 of them were included in this review. ExPEC accounted for 46.0% (1,238/2,692) of bacteria-related invasive diseases in patients aged above 60 years in South Korea, followed by China (44.4% (284/640)), Taiwan (39.0% (1,244/3,194)), and Japan (18.1% (581/3,206)), while Australia reported ExPEC out of all pathogens (54.7% (4,006/7,330)) in general adults. Comorbidities such as diabetes or cancer were common in these patients. Studies reported increases in length-of-stay, and in-hospital 30-day all-cause mortality related to ExPEC associated bacteremia was between 9% to 12%. From a cost perspective, a 3-fold increase in sepsis-associated cost was reported in South Korea between 2005 and 2012. In Australia, antimicrobial resistance contributed to an additional cost of AUD $5.8 million per year (95% uncertainty interval [UI], $2.2-$11.2 million) in the treatment of bloodstream infections (BSIs).

CONCLUSION

ExPEC was a major cause of blood stream infection across China, Japan, South Korea, Taiwan, and Australia. Both the clinical and economic burden associated to ExPEC infections as well as the antimicrobial resistance observed in the elderly call for preventive and curative actions in these regions.

Risk factors and diagnostic markers for Escherichia coli bloodstream infection in older patients

OBJECTIVE

To investigate risk factors for Escherichia coli (E. coli) bloodstream infection (BSI) in older patients and the diagnostic accuracy of laboratory parameters.

METHODS

The electronic medical records of patients aged 60 years and above who were admitted with a serious condition were extracted. Propensity score matching (PSM) was used to ensure that the included patients had similar baseline clinical features. Multiple regression analysis was used to identify risk factors for E. coli BSI and extended-spectrum β-lactamase (ESBL)-producing E. coli BSI. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic utility of relevant laboratory indicators.

RESULTS

After PSM, 508 patients were included: 254 patients with E. coli BSI and 254 control patients. Bile duct stone (adjusted odds ratio [aOR] 5.131), kidney stone (aOR 3.678), and urinary system infection (aOR 3.173) were independent risk factors for E. coli BSI. Prior exposure to cephems (aOR 3.782) and drainage tube placement (aOR 2.572) were independent risk factors for ESBL-producing E. coli BSI. Serum procalcitonin (PCT) yielded the highest area under the curve (0.783) and the best cut-off value (1.3 ng/ml).

CONCLUSION

Bile duct stone, kidney stone, and urinary system infection must be detected and treated early, in order to prevent E. coli BSI in older patients. Further, administration of cephems and invasive procedures must be undertaken with caution, in order to reduce the risk of BSI with ESBL-producing E. coli. Finally, serum PCT level has potential as diagnostic marker for E. coli BSI in older individuals.

Combined Molecular and Phenotypic Antimicrobial Susceptibility Testing Is Beneficial in Detection of ESBL and AmpC Beta-Lactamase Producing Isolates of Enterobacteriaceae in Pediatric Patients with Bloodstream Infections

Objectives: The aim was to assess the potential advantage of combined genotypic testing with phenotypic antimicrobial susceptibility testing (AST) to detect AmpC β-lactamases (AmpC) and extended-spectrum β-lactamases (ESBL) producing Enterobacteriaceae isolated from blood cultures in a pediatric population. Materials and Methods: All first-time Enterobacteriaceae isolates recovered from blood cultures of pediatric patients at the Cincinnati Children's Hospital Medical Center between January 2017 and December 2018 were evaluated. The Check-MDR CT103XL β-lactamase assay was used to determine the presence of AmpC and ESBL, while AST was performed using the VITEK 2 platform. Phenotypic ESBL resistance was defined by resistance to either ceftriaxone or ceftazidime using Clinical and Laboratory Standards Institute breakpoints, while combined cefoxitin resistance with ceftriaxone or ceftazidime resistance was used to detect AmpCs (as per European Committee on Antimicrobial Susceptibility Testing standards). Results: Overall, there were 170 isolates. Genotypically, 21 (12.4%) had AmpC and 18 (10.6%) had ESBL genes detected. Phenotypically, 11 (6.5%) isolates were AmpC and 26 (15.3%) were ESBL producing organisms. Genotypic testing identified an additional 14 AmpC and two ESBL isolates that failed to meet phenotypic criteria. Conclusions: Using combined genotypic and phenotypic methods to detect AmpC and ESBL producing organisms increased the identification of resistant organism and provided potentially clinical relevant data to guide the treatment of resistant organisms.

Past history of stage I/II solid tumor malignancy impacts considerably on sepsis mortality: a propensity score matching analysis from the hellenic sepsis study group

Background

Whether past history of solid stage I/II inactive cancer has an impact on 28-day mortality of sepsis remains unclear. We aimed to determine the impact of history of stage I or II solid tumor malignancy in complete remission the last 3 years on sepsis outcome.

Methods

Using the database of the Hellenic Sepsis Study Group from 1553 patients with sepsis admitted in the ICU, 83 patients with sepsis by Sepsis-3 definition with past-history of stage I/II inactive solid malignancy the last 3 years were depicted. A comparator group of 83 patients fully matched for age, severity, type of infection and comorbidities was selected by propensity score matching.

Results

Mortality after 28 days was 37.3% in the comparator group and 54.2% in the solid tumor stage I/II group (odds ratio for death 1.98; p: 0.030). Following step-wise forward Cox regression analysis, septic shock (hazard ratio 1.80), acute renal injury (hazard ratio 2.06), history of coronary heart disease (hazard ratio 0.36) and history of stage I/II solid tumor malignancy (hazard ratio 1.79) were the only independent variables associated with 28-day mortality. Serum levels of procalcitonin and of soluble urokinase plasminogen activator receptor were similar between the two groups of comparisons.

Conclusions

Past history of stage I/II solid malignancy is an independent risk factor for unfavorable outcome from sepsis the first 28 days.

Clinical outcome of Escherichia coli bloodstream infection in cancer patients with/without biofilm formation: a single-center retrospective study

Background

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is one of the main antimicrobial-resistant pathogens. Little data are available on how biofilm formation (BF) contributes to EC-caused bloodstream infection (BSI) in cancer patients. This study investigated the impact of BF on clinical outcomes of cancer patients with EC-caused BSI.

Methods

Clinical outcome and microbiological characteristics including the presence of bla genes in ESBL-EC isolates were retrospectively collected from BSI cancer patients. Patients infected with ESBL-EC were compared with patients infected with third-generation cephalosporin-susceptible strains. Survival curves were generated by Kaplan–Meier analysis and the survival difference was assessed by the log-rank test. Risk factors for ESBL-EC infection, predictors of mortality, and outcome differences were determined by multivariate logistic regression and Cox regression analysis, respectively.

Results

A high prevalence of ESBL-EC with dominant bla_CTX-M-15, bla_CTX-M-15 plus bla_TEM-52 genotype was found in BSI cancer patients. Independent risk factors for infection with ESBL-EC were cephalosporins, chemotherapy, and BF. Metastasis, ICU admission, BF-positive ESBL-EC, organ failure, and the presence of septic shock were revealed as predictors for mortality. The ESBL characteristic was associated with the BF phenotype, and the overall mortality was significantly higher in cancer patients with BF-positive ESBL-EC-caused BSI.

Conclusion

bla_CTX-M-15 type ESBL-EC is highly endemic among cancer patients with BSI. BF is associated with multi-drug resistance by ESBL-EC and is also an independent risk factor of mortality for cancer patients with BSI. Our findings suggest that the combination of BF-positive ESBL-EC isolates with other appropriate laboratory indicators might benefit infection control and improve clinical outcomes.

No association between resistance mutations, empiric antibiotic, and mortality in ceftriaxone-resistant Escherichia coli and Klebsiella pneumoniae bacteremia

The objective of this study was to correlate resistance mutations of extended spectrum beta-lactamases (ESBL) and AmpC beta-lactamases and virulence factors (VF) with 30-day mortality in patients treated with either piperacillin-tazobactam or carbapenems. A post-hoc analysis on 123 patients with ceftriaxone-resistant Escherichia coli and Klebsiella pneumoniae bacteremia treated empirically with piperacillin-tazobactam and carbapenems was performed. Beta-lactamase resistance mutations and VF were identified by whole genome sequencing (WGS). The primary endpoint was 30-day mortality. Multivariate analyses were performed using logistic regression. WGS showed diverse multilocus sequence types (MLST) in 43 K. pneumoniae strains, while ST131 predominated in E. coli strains (57/80). CTX-M was most commonly detected (76/80 [95%] of E. coli; 39/43 [91%] of K pneumoniae.), followed by OXA (53/80 [66%] of E. coli; 34/43 [79%] of K. pneumoniae). A significant correlation was found between the number of genes encoding third-generation cephalosporin-resistant beta-lactamases and 30-day mortality (p = 0.045). The positive association was not significant after controlling for empiric carbapenem, Pitt score 3 and K. pneumoniae (OR 2.43, P = 0.073). None of the VF was associated with 30-day mortality. No association was found between 30-day mortality and any ESBL and AmpC beta-lactamases or VF when piperacillin-tazobactam or carbapenems were given. No significant association between 30-day mortality and active empiric therapy was found.

In-Hospital Surgery as a Risk Factor for Onset of AmpC-Producing Escherichia coli Blood Stream Infections

There has been a progressive rise in the incidence of blood stream infections (BSI) caused by multidrug-resistant Gram-negative organisms (MDR GN), which cause increased morbidity and mortality. For this reason, recent studies have focused on risk factors of acquisition of carbapenemase-producing Enterobacteriaceae and extended-spectrum beta-lactamase producers. However, there is limited data on risk factors for BSI caused by AmpC-producing Enterobacteriaceae (AmpC EC), especially in low prevalence settings such as Australia. This study was performed to identify risk factors for acquisition of AmpC E. coli, using a retrospective matched case control design over a 3-year period. Patients with BSI caused by AmpC E. coli were matched with controls (third generation cephalosporin susceptible E. coli) by age and site of infection (n = 21). There was no significant difference in age, sex, clinical outcome, time to onset of BSI, recent antibiotic use (last 3 months), comorbidities (type 2 diabetes mellitus, renal failure) intensive care unit admission, underlying hematological condition, immunosuppressant use, APACHE II score, or any recent urological procedures (within last 3 months) between the two groups. On univariate analysis, the AmpC E. coli group were more likely to have had a surgical procedure in hospital and lived in a residential aged care facility. On multivariate logistic regression analysis, a recent surgical procedure was associated with the onset of AmpC E. coli BSI (Odd's Ratio (OR) 4.78, p = 0.034). We concluded that in a relatively low prevalence setting such as Australia, AmpC E. coli BSI is potentially associated with surgery performed in hospital due to previous antibiotic exposure and longer hospitalization.