Risk Factors for Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Community-Onset Bloodstream Infection: Impact on Long-Term Care Hospitals in Korea

Bacteriophage as a novel therapeutic approach for killing multidrug-resistant Escherichia coli ST131 clone

The emergence of the multidrug-resistant (MDR) Escherichia coli ST131 clone has significantly impacted public health. With traditional antibiotics becoming less effective against MDR bacteria, there is an urgent need for alternative treatment options. This study aimed to isolate and characterize four lytic phages (EC.W2-1, EC.W2-6, EC.W13-3, and EC.W14-3) from hospital sewage water and determine their effectiveness against the ST131 clone. These phages demonstrated a broad host range, effectively lysing 94.4% of highly pathogenic E. coli ST131 isolates. Morphological observations and phylogenetic analysis indicate that EC.W2-1, and EC.W13-3 belong to the Tequatrovirus genus in the Straboviridae family, while EC.W2-6 and EC.W14-3 are part of the Kuravirus genus in the Podoviridae family. Phages remained stable at pH 2-10 for 4 h and below 80°C for 1 h. These four phages showed in vitro bacterial lytic activity at various MOIs (0.1-0.001). The one-step growth curve of phages exhibited a short latent period of approximately 10-20 min and a moderate burst size of 50-80 (pfu/cell). Phages' genome size ranged from 46,325-113,909 bp, with G + C content of 35.1 -38.3%. No virulence or drug resistance genes were found, which enhanced their safety profile. In vivo, EC.W2-6 and EC.W13.3, along with their cocktail, fully protected against the ESBL-producing E. coli ST131 infection model in vivo. Combining these phages and a 3-day repeated single phage, EC.W13-3 significantly enhanced the survival rate of E. coli ST131 infected mice at low MOI (0.01-0.001). The in vivo effectiveness of the isolated phages and the EC.W2-6 and EC.W14-3 cocktail in highly reducing bacterial load CFU/g in multiple organs strongly supports their potential efficacy. Based on in vivo, in vitro, and genomic analyses, phages have been proposed as novel and suitable candidates for killing the pandemic ST131 clone.

Extended spectrum beta-lactamase carriage among elderly residents of a long-term care facility in Beirut

BACKGROUND

Antimicrobial resistance is an emerging problem worldwide, endangering antimicrobials efficacy and resulting in high rates of morbidity and mortality. It is one of the major concerns that health care facilities are facing nowadays. Mainly, extended-spectrum beta-lactamases (ESBL)-producing Enterobacterales play a role in hydrolyzing β-lactams, specifically the third-generation cephalosporins. This study aimed to investigate the prevalence of fecal carriage and molecular characterization of ESBL-producing Enterobacterales among Lebanese elderly residents in a long-term care facility (Dar Al-Ajaza Al Islamia Hospital).

METHODS

Rectal culture swab specimens were collected from 132 patients at Dar Al Ajaza Al Islamia hospital between January 2019 till June 2020. The phenotype of ESBL producers was confirmed by a modified double disc synergy test and antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method. Genotypically, multiplex polymerase chain reaction was used to detect the ESBL genes.

RESULTS

The main Enterobacterales strain observed was E coli (90.15%) followed by Klebsiella pneumoniae (4.54%) and Klebsiella oxytoca (3.80%). It has been found that the ESBL percentage rate has decreased when compared to a study conducted previously at the same hospital. Moreover, the predominant ESBL gene was CTX-M (cefotaximase).

CONCLUSIONS

This study is the first to demonstrate the improved current status of ESBL in one long-term care facility. In addition, the CTX-M is still the major type in ESBL-producing organisms.

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.

Growing threat of extended-spectrum β-lactamase-producing Enterobacteriaceae colonisation in high-risk pregnancies: A cross-sectional study

OBJECTIVE

To investigate the epidemiological changes in extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) vaginal colonisation in pregnant women deemed at high risk, and to identify independent risk factors. Further, the differences in perinatal outcomes according to maternal ESBL-E vaginal colonisation were analysed.

DESIGN

Cross-sectional study.

SETTING

Republic of Korea.

POPULATION

A cohort of 1460 women admitted to our high-risk pregnancy unit between 14⁺⁰ and 36⁺⁶  weeks of gestation.

METHODS

The trend of changes in the association of ESBL-E vaginal colonisation from January 2010 to December 2020 was analysed. The main outcomes were analysed over the study period and ESBL-E vaginal colonisation.

MAIN OUTCOME MEASURES

Rate of ESBL-E vaginal colonisation, risk factors for ESBL-E vaginal colonisation and perinatal outcomes.

RESULTS

The ESBL-E vaginal colonisation rate has tended to increase over the past 11 years, which was attributed to a significantly higher proportion of ESBL-producing Escherichia coli. Cerclage (RR 3.7, 95% CI 2.19-6.40) and prior antibiotic treatment (RR 4.0, 95% CI 2.44-6.54) were found as independent risk factors for ESBL-E vaginal colonisation. Earlier gestational age at delivery and higher proven early-onset neonatal sepsis (EONS) rate were observed in the ESBL-E-positive group.

CONCLUSIONS

The ESBL-E vaginal colonisation rate in pregnant patients at high risk has increased over the past decade, and the independent risk factors for colonisation are cerclage and prior antibiotic treatment. Additionally, maternal ESBL-E vaginal colonisation is associated with higher rates of proven EONS.

Factors Associated with Extended-spectrum β-lactamase-producing Enterobacteria Isolated from Respiratory Samples

Objective Although extended-spectrum β-lactamase (ESBL)-producing bacteria are a global threat, as they may cause respiratory infection, the factors associated with the isolation of these bacteria from sputum remain unclear. We therefore explored the factors related to ESBL-producing Klebsiella pneumoniae and Escherichia coli isolated from sputum samples. Patients and Methods This study included consecutive patients admitted to our department from 2010 to 2021 with K. pneumoniae or E. coli isolated from their sputum. The patients were categorized into ESBL-producing and non-ESBL-producing groups, and the factors associated with ESBL-producing bacteria isolation were assessed using a binomial logistic regression analysis. Results We included 82 patients, and ESBL-producing pathogens were isolated from 23 (28%). The usage rates of cephem [odds ratio (OR) 4.000, 95% confidence interval (CI) 1.402-11.409, p=0.010], quinolone (OR 2.961, 95% CI 1.097-7.996, p=0.032), and macrolide (OR 4.273, 95% CI 1.518-12.028, p=0.006) in the past year were significantly higher in the ESBL-producing group than in the non-ESBL-producing group. The multivariate analysis revealed that the applications of cephem (adjusted OR: 4.130, 95% CI: 1.233-13.830, p=0.021) and macrolide (adjusted OR: 6.365, 95% CI: 1.922-21.077, p=0.002) was independently associated with the isolation of ESBL-producing bacteria. Conclusions A history of cephem and macrolide use can be considered a risk factor for ESBL-producing bacteria isolation from sputum samples. Physicians need to consider these risk factors when determining antibiotics for the treatment of patients with respiratory infections.

Mass Spectrometry-Based Detection of Beta Lactam Hydrolysis Enables Rapid Detection of Beta Lactamase Mediated Antibiotic Resistance

OBJECTIVE

Antibiotic resistance by beta lactamase expression is a serious and growing threat. We aimed to determine whether beta-lactamase activity is detectable in urine specimens to enable faster identification of resistance.

METHODS

Urine specimens from patients with extended spectrum beta lactamase (ESBL)-expressing urinary infections were incubated with beta lactam antibiotics. Beta lactam hydrolysis was determined by mass spectrometry methods.

RESULTS

Ceftriaxone hydrolysis was observed in 45 of 45 ESBL-containing specimens from patients not treated with a beta lactamase inhibitor before specimen collection. Ceftriaxone hydrolysis was not observed in 108 of 108 non-ESBL-containing specimens. Spiking studies show that beta lactam hydrolysis can be observed within 30 minutes. Beta lactam hydrolysis is evidenced by mass spectrometry preceded by either liquid chromatography or matrix-assisted laser desorption ionization specimen processing methods.

CONCLUSION

Clinically significant beta lactamase activity is detectable directly from urine specimens. The described methods would enable the detection of beta lactam resistance 24 to 48 hours sooner than culture based methods.