Incidence of fecal Enterobacteriaceae producing broad-spectrum beta-lactamases in patients with hematological malignancies

Clinical microbiology and its role in current medicine

The characteristics of current clinical microbiology and its role in modern medicine are presented. The article defines the main objectives of microbiological examination, principles of antibiotic and diagnostic stewardship. The main emphasis is placed on the correct interpretation of microbiological results.

Bacterial Infections, Antimicrobial Resistance and Antibiotic Therapy

Bacterial infections have been, and are very likely to continue to be, among the most serious problems in medicine [...].

Modelling and Simulation of the Effect of Targeted Decolonisation on Incidence of Extended-Spectrum Beta-Lactamase-Producing Enterobacterales Bloodstream Infections in Haematological Patients

Introduction

Haematological patients are at higher risk of bloodstream infections (BSI) after chemotherapy. The aim of this study was to develop a simulation model assessing the impact of selective digestive decontamination (SDD) of haematological patients colonised with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) on the incidence of ESBL-E BSI after chemotherapy.

Methods

A patient population was created by a stochastic simulation model mimicking the patients’ states of colonisation with ESBL-E during hospitalisation. A systematic literature search was performed to inform the model. All ESBL-E carriers were randomised (1:1) to either the intervention (targeted SDD) or the control group (placebo). ESBL-E BSI incidence was the outcome of the model. Sensitivity analyses were performed by prevalence of ESBL-E carriage at hospital admission (low: < 10%, medium: 10–25%, high: > 25%), duration of neutropenia after receiving chemotherapy, administration of antibiotic prophylaxis with quinolones, and time interval between SDD and chemotherapy.

Results

The model estimated that the administration of targeted SDD before chemotherapy reduces the incidence of ESBL-E BSI in the hospitalised haematological population up to 27%. The greatest benefit was estimated in high-prevalence settings, regardless of the duration of neutropenia, the time interval before chemotherapy, and the administration of antibiotic prophylaxis with quinolones (p < 0.05). In medium-prevalence settings, SDD was effective in patients receiving quinolone prophylaxis, with either 1-day time interval before chemotherapy and a neutropenia duration > 6 days (p < 0.05) or 7-day time interval before chemotherapy and a neutropenia duration > 9 days (p < 0.05). No benefit was observed in low-prevalence settings.

Conclusions

Our model suggests that targeted SDD could decrease the rate of ESBL-E BSI in haematological carriers before chemotherapy in the setting of high ESBL-E prevalence at hospital admission. These estimates require confirmation by well-designed multicentre RCTs, including the assessment of the impact on resistance/disruption patterns of gut microbiome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00550-3.

Implementation of Antibiotic Stewardship in a University Hospital Setting

The article describes activities of an antibiotic center at a university hospital in the Czech Republic and presents the results of antibiotic stewardship program implementation over a period of 10 years. It provides data on the development of resistance of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus to selected antibiotic agents as well as consumption data for various antibiotic classes. The genetic basis of resistance to beta-lactam antibiotics and its clonal spread were also assessed. The study showed significant correlations between aminoglycoside consumption and resistance of Escherichia coli and Klebsiella pneumoniae to gentamicin (r = 0.712, r = 0.869), fluoroquinolone consumption and resistance of Klebsiella pneumoniae to ciprofloxacin (r = 0.896), aminoglycoside consumption and resistance of Pseudomonas aeruginosa to amikacin (r = 0.716), as well as carbapenem consumption and resistance of Pseudomonas aeruginosa to meropenem (r = 0.855). Genotyping of ESBL- positive isolates of Klebsiella pneumoniae and Escherichia coli showed a predominance of CTX-M-type; in AmpC-positive strains, DHA, EBC and CIT enzymes prevailed. Of 19 meropenem-resistant strains of Klebsiella pneumoniae, two were identified as NDM-positive. Clonal spread of these strains was not detected. The results suggest that comprehensive antibiotic stewardship implementation in a healthcare facility may help to maintain the effectiveness of antibiotics against bacterial pathogens. Particularly beneficial is the work of clinical microbiologists who, among other things, approve administration of antibiotics to patients with bacterial infections and directly participate in their antibiotic therapy.

Analysis of Vancomycin-Resistant Enterococci in Hemato-Oncological Patients

Enterococci are important bacterial pathogens, and their significance is even greater in the case of vancomycin-resistant enterococci (VRE). The study analyzed the presence of VRE in the gastrointestinal tract (GIT) of hemato-oncological patients. Active screening using selective agars yielded VRE for phenotypic and genotypic analyses. Isolated strains were identified with MALDI-TOF MS, (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) their susceptibility to antibiotics was tested, and resistance genes (vanA, vanB, vanC-1, vanC2-C3) and genes encoding virulence factors (asa1, gelE, cylA, esp, hyl) were detected. Pulsed-field gel electrophoresis was used to assess the relationship of the isolated strains. Over a period of three years, 103 VanA-type VRE were identified in 1405 hemato-oncological patients. The most frequently detected virulence factor was extracellular surface protein (84%), followed by hyaluronidase (40%). Unique restriction profiles were observed in 33% of strains; clonality was detected in 67% of isolates. The study found that 7% of hemato-oncological patients carried VRE in their GIT. In all cases, the species identified was Enterococcus faecium. No clone persisted for the entire 3-year study period. However, genetically different clusters were observed for shorter periods of time, no longer than eight months, with identical VRE spreading among patients.

Prevalence of Asymptomatic Bacteriuria and Antibiotic Susceptibility Patterns of Bacterial Isolates among Cancer Patients and Healthy Blood Donors at the University of Gondar Specialized Hospital

Background

Urinary tract infections are the common types of infections in the community and health care settings. Despite the widespread availability of antibiotics, urinary tract infection remains a worldwide therapeutic problem. It is a continuous and significant problem in cancer patients.

Methods

A hospital-based comparative cross-sectional study was conducted on 240 study participants from January to June 2019. Sociodemographic data were collected by a predesigned questionnaire and midstream urine samples collected using simple random sampling technique by using clean, sterile plastic cups and then inoculated onto CLED agar plates and incubated at 37°C for 24 hours. Urine culture was considered significant bacteriuria when colony forming units ≥10⁵/mL of voided urine and a single pure colony suspended in nutrient broth and then subcultured onto a blood agar plate and MacConkey agar plate, incubated at 37°C for 24 hours for identification. Identification was done by using standard microbiological methods. Modified Kirby–Bauer disk diffusion technique was applied for antimicrobial susceptibility testing in accordance with CLSI 2018 criteria. Data were entered, cleared, and checked using Epi Info version 7 and exported to SPSS version 20 for analysis. The results were displayed using tables and figures. p value <0.05 at 95% CI was considered as statistically significant.

Results

The overall prevalence of asymptomatic bacteriuria in cancer patients was 23.3% while 6.7% in apparently healthy blood donors. E. coli (32.1%) was the commonest isolated uropathogenic bacteria followed by Klebsiella species (25.0%), S. aureus (21.4%), Enterococcus species (10.7%), Serratia species (7.1%), and Enterobacter aerogenes (3.6%) in cancer patients. In apparently healthy blood donors, E. coli, Klebsiella species, and S. aureus were isolated from 75%, 12.5%, and 12.5%, respectively. Most Gram-negative bacteria were more sensitive to ceftazidime, cefoxitin, nalidixic acid, nitrofurantoin, norfloxacin, ciprofloxacin, and tobramycin, whereas highly resistant to ampicillin, penicillin, tetracycline, and ceftazidime. S. aureus isolates were 100% susceptible to nitrofurantoin.

Conclusions

This study showed a high prevalence of asymptomatic bacteriuria among cancer patients (23.3%) compared to apparently healthy blood donors (6.7%). E. coli was isolated predominately. Nitrofurantoin and ciprofloxacin should be used to treat asymptomatic bacteriuria in the study area.

Fecal Carriage of Extended-Spectrum β-Lactamase and Carbapenemase-Producing Enterobacterales Strains in Patients with Colorectal Cancer in the Oncology Unit of Amizour Hospital, Algeria: A Prospective Cohort Study

Background: The prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E) and carbapenemase-producing Enterobacterales (CPE) is now disseminated worldwide. This study aims to describe the prevalence of ESBL and CPE fecal carriage in colorectal cancer patients. Methods: All patients admitted to the oncology service of Amizour hospital (Algeria) for colorectal cancer chemotherapy from March to May 2019 were screened for ESBL-E or CPE fecal carriage. After culturing on chromogenic media, the presumptive colonies were identified by mass spectroscopy. Antibiotic susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing. The β-lactamases encoding genes and plasmid-mediated quinolone-resistant genes were screened by PCR and sequencing. Results: ESBL-E strains were recovered from rectal swabs in 6 patients (14.3%) and only 1 patient (2.4%) was found a carrier for OXA-48-producing Klebsiella pneumoniae. The most frequently encountered species among ESBL-E was Escherichia coli (n = 5), followed by K. pneumoniae (n = 1). PCR and sequencing showed that four isolates harbored the bla_CTX-M-15 gene and two strains harbored the bla_CTX-M-14 gene. Also, one strain of K. pneumoniae was found to harbor both qepA and qnrS genes. Conclusion: This study highlighted the fecal carriage of ESBL-E and OXA-48-producing Enterobacterales strains in colorectal cancer patients.

Colonization and infection with extended-spectrum beta-lactamase producing Enterobacteriaceae in patients with malignancy

INTRODUCTION

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) constitute a global threat and are prevalent in both nosocomial and community settings. These pathogens have been associated with delays in initiation of appropriate antimicrobial therapy and worse clinical outcomes. Patients with solid or hematologic malignancy represent a high-risk population for both colonization and infection with ESBL-PE. Areas covered: A description of the microbiology and epidemiology of the ESBL-PE is presented. Also, we explore studies on ESBL-PE colonization and infection, and examine areas where future research is needed. Expert commentary: ESBL-PE constitute an increasing threat to patients with malignancy. Unfortunately, substantial geographic variations as well as knowledge gaps in certain regions of the world limit our ability to reach conclusions that are valid globally. Furthermore, there is limited evidence regarding the optimal ways to prevent and manage infections caused by ESBL-PE. Research is urgently needed to elucidate these areas and allow the institution of appropriate infection control and antimicrobial stewardship policies and recommendations.

Colonisation with extended-spectrum β-lactamase-producing Enterobacteriaceae and risk for infection among patients with solid or haematological malignancy: a systematic review and meta-analysis

Cancer patients are vulnerable to infections, including those with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE), and most of these infections are associated with colonisation of the gastrointestinal tract. The aim of this study was to estimate the prevalence of gastrointestinal colonisation with ESBL-PE cancer populations and to determine the risk for subsequent bloodstream infection (BSI) with these pathogens. PubMed and EMBASE databases were searched from 1 January 1991 to 1 March 2016 to identify studies regarding ESBL-PE colonisation among patients with malignancies. Ten studies (out of 561 non-duplicate articles) were included, providing data on 2211 patients. The pooled prevalence of ESBL-PE colonisation was 19% [95% confidence interval (CI) 8-32%]. Stratifying per region, the pooled prevalence in Europe was 15% (95% CI 10-21%), whereas in Asia the pooled prevalence was 31% (95% CI 4-69%). In addition, the pooled prevalence was 15% (95% CI 7-24%) among patients with haematological malignancy, whereas no studies were identified that included solely patients with solid tumours. Notably, cancer patients with ESBL-PE colonisation were 12.98 times (95% CI 3.91-43.06) more likely to develop a BSI with ESBL-PE during their hospitalisation compared with non-colonised patients. We found that, overall, one in five patients with cancer is colonised with ESBL-PE and the incidence can be as high as one in three in Asia. This is important because colonisation was associated with an almost 13 times higher risk for developing BSI with ESBL-PE. Screening measures should be evaluated to identify their clinical benefit in patients with malignancy.