The effect of a hospital-wide urine culture screening intervention on the incidence of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella species

Limiting the Spread of Multidrug-Resistant Bacteria in Low-to-Middle-Income Countries: One Size Does Not Fit All

The spread of multidrug-resistant organisms (MDRO) is associated with additional costs as well as higher morbidity and mortality rates. Risk factors related to the spread of MDRO can be classified into four categories: bacterial, host-related, organizational, and epidemiological. Faced with the severity of the MDRO predicament and its individual and collective consequences, many scientific societies have developed recommendations to help healthcare teams control the spread of MDROs. These international recommendations include a series of control measures based on surveillance cultures and the application of barrier measures, ranging from patients' being isolated in single rooms, to the reinforcement of hand hygiene and implementation of additional contact precautions, to the cohorting of colonized patients in a dedicated unit with or without a dedicated staff. In addition, most policies include the application of an antimicrobial stewardship program. Applying international policies to control the spread of MDROs presents several challenges, particularly in low-to-middle-income countries (LMICs). Through a review of the literature, this work evaluates the real risks of dissemination linked to MDROs and proposes an alternative policy that caters to the means of LMICs. Indeed, sufficient evidence exists to support the theory that high compliance with hand hygiene and antimicrobial stewardship reduces the risk of MDRO transmission. LMICs would therefore be better off adopting such low-cost policies without necessarily having to implement costly isolation protocols or impose additional contact precautions.

The Effect of Infection Precautions on Extended-Spectrum Beta-Lactamase Enterobacteriaceae Colonization Among Nurses in Three Beirut Hospitals

Background and objective

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) are rapidly emerging worldwide. This study aimed to assess the effect of contact precaution (CP) on ESBL-PE-colonization rates among nurses in three hospitals in Beirut, Lebanon, where ESBL is endemic, in order to define the risk factors for colonization. Accordingly, the ongoing use of CP to prevent ESBL-PE transmission to healthy nurses was evaluated.

Methods

This cross-sectional study was conducted in three hospitals. Hospital 1 required CP, Hospital 2 had recently stopped CP, and Hospital 3 had stopped it three years previously. Questionnaires and stool-collection containers were distributed to all patient care nurses in those three hospitals. The Returned samples were tested using the agar dilution technique.

Results

A total of 269 out of 733 nurses volunteered to participate; 140 met the inclusion criteria (no recent hospitalization, antibiotic use, or known ESBL-PE colonization) and provided samples. Among them, 15% were ESBL-positive. Compared to nurses from Hospital 3, nurses from Hospital 1 were 59% less likely to be colonized, while nurses from Hospital 2 were 62% more likely to be colonized.

Conclusion

In hospitals where CP is in place for ESBL-positive patients, ESBL-PE prevalence in nursing staff was significantly lower. Additionally, a work experience of two to four years increased the odds of ESBL-PE colonization in comparison with longer nursing experience. CP may be a justifiable means of protection against ESBL-PE transmission to healthy nurses. The risk factors for colonization were discontinuation of CP and a shorter clinical work experience.

Is systematic fecal carriage screening of extended-spectrum beta-lactamase-producing Enterobacteriaceae still useful in intensive care unit: a systematic review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are disseminating worldwide leading to increased hospital length of stay and mortality in intensive care units (ICU). ESBL-E dissemination was first due to outbreaks in hospital settings which led to the implementation of systematic fecal carriage screening to improve hygiene procedures by contact precautions. ESBLs have since spread in the community, and the relevance of contact precautions is questioned. ESBL-E dissemination led to an overuse of carbapenems triggering the emergence of carbapenem-resistant Enterobacteriaceae. Empirical antimicrobial therapy based on ESBL-E fecal carriage has been proposed but is debated as it could increase the consumption of carbapenems among ESBL-E carriers without any clinical benefit. Finally, selective decontamination among ESBL-E fecal carriers is evoked to decrease the risk for subsequent ESBL-E infection, but its efficacy remains debated. We propose to systematically review the evidence to recommend or not such systematic ESBL-E fecal carriage screening in adult ICU.

METHODS

Every article focusing on ESBL-E and ICU available on the MEDLINE database was assessed. Articles were included if focusing on cross-transmission, efficacy of hygiene procedures, link between ESBL-E colonization and infection or guidance of empirical therapy or selective decontamination efficacy.

RESULTS

Among 330 articles referenced on PubMed, 39 abstracts were selected for full-text assessment and 25 studies were included. Systematic screening of ESBL-E fecal carriage to guide contact precautions do not seem to decrease the rate of ESBL-E cross-transmission. It has a very good negative predictive value for subsequent ESBL-E infections but a positive predictive value between 40 and 50% and so does not help to spare carbapenems. Cessation of ESBL-E carriage systematic screening could decrease the use of carbapenems in ICU without any clinical harm. Nevertheless, further studies are needed to validate these results from monocentric before-after study. Selective decontamination strategy applied to ESBL-E fecal carriers could be helpful, but available data are conflicting.

CONCLUSION

Current knowledge lacks of high-quality evidence to strongly recommend in favor of or against a systematic ESBL-E fecal carriage screening policy for ICU patients in a non-outbreak situation. Further evaluation of selective decontamination or fecal microbiota transplantation among ESBL-E fecal carriers is needed.

The Activity of Fosfomycin Against Extended-Spectrum Beta-Lactamase-Producing Isolates of Enterobacteriaceae Recovered from Urinary Tract Infections: A Single-Center Study Over a Period of 12 Years

Despite global efforts to tackle resistance in extended-spectrum beta-lactamase (ESBL)-producing isolates via old antibiotics, there are limited data on the efficacy of fosfomycin-an old oral antibiotic-against Enterobacteriaceae in the Middle East. The purpose of this study was to evaluate the in vitro activity of fosfomycin against urinary ESBL-producing isolates of Enterobacteriaceae. Between 2004 and 2015, 363 isolates of ESBL-producing Enterobacteriaceae were recovered from high-risk patients suffering from cardiac disorders and were subjected to polymerase chain reaction using specific primers for the bla_TEM, bla_SHV, and bla_CTX-M genes. Antibiotic susceptibility testing was performed for fosfomycin and other antibiotic comparators. For the isolates considered nonsusceptible to fosfomycin by disk diffusion, the minimum inhibitory concentration (MIC) was determined. The susceptibility rate to fosfomycin remained almost steady (90-100%) over a 12-year period, although it fluctuated vis-à-vis ciprofloxacin (0-54%), trimethoprim/sulfamethoxazole (9.1-31.7%), and nitrofurantoin (41.7-100%). Of all the antibiotics tested, fosfomycin was the most active antimicrobial agent (97%) against the ESBL-positive isolates. Fosfomycin maintained higher activity against ESBL-Escherichia coli than against ESBL-Klebsiella pneumoniae. Only 11 (3%) isolates were not susceptible to fosfomycin according to disk diffusion and they had MICs greater than 1,024 mg/ml. All of the fosfomycin-nonsusceptible isolates were positive for the bla_CTX-M gene (100%), while 5 (45.4%) and 3 (27.3%) of the isolates harbored the bla_TEM and bla_SHV genes, respectively. We showed that fosfomycin had a numerically higher susceptibility rate than the other antibiotics against the ESBL-producing isolates of the most common Enterobacteriaceae. Given its low resistance rate and oral administration, fosfomycin may be deemed a promising antibiotic for the treatment of urinary tract infections caused by ESBL-producing Enterobacteriaceae.

Incidence of Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli and Klebsiella Infections in the United States: A Systematic Literature Review

BACKGROUND

Despite a reported worldwide increase, the incidence of extended-spectrum β-lactamase (ESBL) Escherichia coli and Klebsiella infections in the United States is unknown. Understanding the incidence and trends of ESBL infections will aid in directing research and prevention efforts.

OBJECTIVE

To perform a literature review to identify the incidence of ESBL-producing E. coli and Klebsiella infections in the United States.

DESIGN

Systematic literature review.

METHODS

MEDLINE via Ovid, CINAHL, Cochrane library, NHS Economic Evaluation Database, Web of Science, and Scopus were searched for multicenter (≥2 sites), US studies published between 2000 and 2015 that evaluated the incidence of ESBL-E. coli or ESBL-Klebsiella infections. We excluded studies that examined resistance rates alone or did not have a denominator that included uninfected patients such as patient days, device days, number of admissions, or number of discharges. Additionally, articles that were not written in English, contained duplicated data, or pertained to ESBL organisms from food, animals, or the environment were excluded.

RESULTS

Among 51,419 studies examined, 9 were included for review. Incidence rates differed by patient population, time, and ESBL definition and ranged from 0 infections per 100,000 patient days to 16.64 infections per 10,000 discharges and incidence rates increased over time from 1997 to 2011. Rates were slightly higher for ESBL-Klebsiella infections than for ESBL-E. coli infections.

CONCLUSION

The incidence of ESBL-E. coli and ESBL-Klebsiella infections in the United States has increased, with slightly higher rates of ESBL-Klebsiella infections. Appropriate estimates of ESBL infections when coupled with other mechanisms of resistance will allow for the appropriate targeting of resources toward research, drug discovery, antimicrobial stewardship, and infection prevention.

Infect Control Hosp Epidemiol 2017;38:1209–1215

In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106): An Innovative Strategy to Possibly Counteract Such Infections in Humans?

GOALS

To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae.

BACKGROUND

Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate.

STUDY

The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium.

RESULTS

L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K.

CONCLUSIONS

Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.

Ceftazidime/Avibactam and Ceftolozane/Tazobactam: Second-generation β-Lactam/β-Lactamase Inhibitor Combinations

Ceftolozane/tazobactam and ceftazidime/avibactam are 2 novel β-lactam/β-lactamase combination antibiotics. The antimicrobial spectrum of activity of these antibiotics includes multidrug-resistant (MDR) gram-negative bacteria (GNB), including Pseudomonas aeruginosa. Ceftazidime/avibactam is also active against carbapenem-resistant Enterobacteriaceae that produce Klebsiella pneumoniae carbapenemases. However, avibactam does not inactivate metallo-β-lactamases such as New Delhi metallo-β-lactamases. Both ceftolozane/tazobactam and ceftazidime/avibactam are only available as intravenous formulations and are dosed 3 times daily in patients with normal renal function. Clinical trials showed noninferiority to comparators of both agents when used in the treatment of complicated urinary tract infections and complicated intra-abdominal infections (when used with metronidazole). Results from pneumonia studies have not yet been reported. In summary, ceftolozane/tazobactam and ceftazidime/avibactam are 2 new second-generation cephalosporin/β-lactamase inhibitor combinations. After appropriate trials are conducted, they may prove useful in the treatment of MDR GNB infections. Antimicrobial stewardship will be essential to preserve the activity of these agents.

The Prevalence and Molecular Epidemiology of Multidrug-Resistant Enterobacteriaceae Colonization in a Pediatric Intensive Care Unit

OBJECTIVE

To determine the prevalence and acquisition of extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpCs (pAmpCs), and carbapenemases ("MDR Enterobacteriaceae") colonizing children admitted to a pediatric intensive care unit (PICU).

DESIGN

Prospective study.

SETTING

40-bed PICU.

METHODS

Admission and weekly thereafter rectal surveillance swabs were collected on all pediatric patients during a 6-month study period. Routine phenotypic identification and antibiotic susceptibility testing were performed. Enterobacteriaceae displaying characteristic resistance profiles underwent further molecular characterization to identify genetic determinants of resistance likely to be transmitted on mobile genetic elements and to evaluate relatedness of strains including DNA microarray, multilocus sequence typing, repetitive sequence-based PCR, and hsp60 sequencing typing.

RESULTS

Evaluating 854 swabs from unique children, the overall prevalence of colonization with an MDR Enterobacteriaceae upon admission to the PICU based on β-lactamase gene identification was 4.3% (n=37), including 2.8% ESBLs (n=24), 1.3% pAmpCs (n=11), and 0.2% carbapenemases (n=2). Among 157 pediatric patients contributing 603 subsequent weekly swabs, 6 children (3.8%) acquired an incident MDR Enterobacteriaceae during their PICU stay. One child acquired a pAmpC (E. coli containing bla DHA) related to an isolate from another patient.

CONCLUSIONS

Approximately 4% of children admitted to a PICU were colonized with MDR Enterobacteriaceae (based on β-lactamase gene identification) and an additional 4% of children who remained in the PICU for at least 1 week acquired 1 of these organisms during their PICU stay. The acquired MDR Enterobacteriaceae were relatively heterogeneous, suggesting that a single source was not responsible for the introduction of these resistance mechanisms into the PICU setting.