Clinical Outcomes of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Infections with Susceptibilities among Levofloxacin, Cefepime, and Carbapenems

Aminoglycoside versus carbapenem or piperacillin/tazobactam treatment for bloodstream infections of urinary source caused by Gram-negative ESBL-producing Enterobacteriaceae

OBJECTIVES

We studied the performance of aminoglycosides in treating bloodstream infections (BSIs) of urinary source caused by ESBL-producing Enterobacteriaceae (ESBL-EB).

METHODS

In a retrospective study of 193 patients with a clinical diagnosis of urinary tract infection, pyelonephritis or urosepsis and blood and urine cultures positive for ESBL-EB, patients were grouped according to whether they were treated with an aminoglycoside, a carbapenem or piperacillin/tazobactam. Multivariate analysis was used to define risk factors for mortality with inverse probability of treatment weighting used to minimize confounding. The primary efficacy outcome was 30 day mortality. The primary safety outcome was acute kidney injury (AKI) at 14 days.

RESULTS

Mean age was 79.3 years. Dementia, chronic kidney disease and the presence of a urinary catheter were common. Thirty-two (16.6%) patients died and risk factors for mortality included age, high Charlson score, presentation with severe sepsis/septic shock and infection with bacteria other than Escherichia coli. Aminoglycosides were non-inferior compared with other antibiotics regarding 30 day mortality [13.0% versus 21.2%, respectively; adjusted risk difference=10.29% (-0.82% to 21.41%)], but did not reach non-inferiority for bacteriuria recurrence [48.9% versus 44.7%, respectively; adjusted risk difference=-8.72% (-30.87% to 13.43%)]. AKI developed at a similar rate in both treatment groups: 12.0% versus 10.6%, respectively [OR=1.14 (0.46-2.81)]. Aminoglycosides were more efficacious in E. coli infections compared with other ESBL-EB.

CONCLUSIONS

We demonstrated the efficacy and safety of aminoglycosides in treating BSI of urinary source caused by ESBL-EB. This carbapenem-sparing approach can assist in avoiding excessive carbapenem use without compromising outcomes.

Stewardship program on carbapenem prescriptions in a tertiary hospital for adults and children in France: a cohort study

Antimicrobial stewardship programs aim at reducing the overuse of broad-spectrum antibiotics such as carbapenems, but their impact remains unclear. We compared the use of carbapenems between paediatric and adult subjects admitted to a French tertiary hospital and described the intervention of an antibiotic stewardship team (AST). As part of AST routine activity, all adult and paediatric patients receiving carbapenems are identified in real time using a computer-generated alert system and reviewed by the AST. Data associated with carbapenem prescriptions were extracted for 2 years (2014-2015) and were compared between paediatric and adult wards. Prescription appropriateness (i.e. no clinically suitable narrower spectrum alternative to carbapenem for de-escalation) and AST intervention were analysed. In total, 775 carbapenem prescriptions for 291 children and 262 adults were included. Most patients (95%) had a comordity and 52% had known recent carriage of extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBLE). Most carbapenem prescriptions came from intensive care units (n = 269, 35%) and were initiated for urinary tract (n = 200, 27%), sepsis (n = 181, 25%), and lung (n = 153, 21%) infections. Carbapenems were initiated empirically in 537 (70%) cases, and an organism was isolated in 523 (67%) cases. Among the isolated organisms, 47% (n = 246) were ESBLE and 90% (n = 468) were susceptible to carbapenems, but an alternative existed in 61% (n = 320) of cases according to antibiotic susceptibility testing. Among prescriptions reviewed by the AST, 39% (n = 255) were considered non-appropriate and led to either antibiotic discontinuation (n = 47, 7%) or de-escalation (n = 208, 32%). Non-appropriate prescriptions were more frequent in paediatric wards (p = 0.01) and in microbiologically documented infections (p = 0.013), and less observed in immunocompromised patients (p = 0.009) or with a known ESBLE carriage (p < 0.001). Tailored stewardship programs are essential to better control carbapenem use and subsequent antimicrobial resistance.

Prevalence and molecular characteristics of ESBL and AmpC β -lactamase producing Enterobacteriaceae strains isolated from UTIs in Egypt

BACKGROUND

Infections caused by Enterobacteriaceae are mainly treated with the β-lactam antibiotics, nevertheless, the emergence of species with plasmid-borne β-lactamases has decreased the efficacy of these antibiotics. Therefore, continuing studies on the resistance pattern of different regions is important for assessment of proper antimicrobial therapy protocols. The study aimed to characterize extended-spectrum β-lactamase (ESBL) and AmpC β -lactamase (AmpC) producing Enterobacteriaceae isolated from community-acquired UTIs in Egypt.

METHODS

Out of 705 urine samples, 440 Enterobacteriaceae isolates were investigated to detect ESBL and AmpC β -lactamases producers by phenotypic and molecular methods.

RESULTS

Out of 440 Enterobacteriaceae isolates, 311 were identified as ESBL producers by phenotypic testing. ESBL genes were detected in 308 isolates. BlaCTX-M-type was the most prevalent 254 (81.6%), out of them blaCTXM-15 was the commonest (152, 48.8%) followed by blaCTX-M-1 (140, 45%), blaCTX-M-8 (72, 23.1%) and lastly blaCTX-M-2 (4, 1.3%). blaTEM gene also was detected in a high rate (189, 60.7%). Two hundred and thirty-five (75.5%) of ESBL producers harbored blaCTX-M in combination with blaTEM and/or blaSHV genes. Multiple drug resistance in the ESBL-producers was significantly (P < 0.05) higher than in non-ESBL producers. Imipenem was the most effective drug against ESBL producers. Among 35 cefoxitin resistant isolates, 18 (51.4%) identified as carrying AmpC genes by multiplex PCR. Within AmpC β -lactamase genes, DHA gene was the predominant gene (15, 42.3%). CIT and MOX genes were also present, but in a low rate (5, 14.2% and 4, 11.4%) respectively. Co-existence of multiple AmpC genes was detected exclusively in K. pneumoniae isolates. E. coli isolates harbored DHA gene only. However, FOX gene was not detected in the study isolates. Seventeen of isolates carrying AmpC genes were also positive for ESBL genes.

CONCLUSION

The study shows that the prevalence of ESBL producing Enterobacteriaceae spread in south Egypt is alarming, however AmpC β -lactamase production is not so high.

Widespread antimicrobial resistance among bacterial infections in a Rwandan referral hospital

BACKGROUND

Resistance among bacterial infections is increasingly well-documented in high-income countries; however, relatively little is known about bacterial antimicrobial resistance in low-income countries, where the burden of infections is high.

METHODS

We prospectively screened all adult inpatients at a referral hospital in Rwanda for suspected infection for seven months. Blood, urine, wound and sputum samples were cultured and tested for antibiotic susceptibility. We examined factors associated with resistance and compared hospital outcomes for participants with and without resistant isolates.

RESULTS

We screened 19,178 patient-days, and enrolled 647 unique participants with suspected infection. We obtained 942 culture specimens, of which 357 were culture-positive specimens. Of these positive specimens, 155 (43.4%) were wound, 83 (23.2%) urine, 64 (17.9%) blood, and 55 (15.4%) sputum. Gram-negative bacteria comprised 323 (88.7%) of all isolates. Of 241 Gram-negative isolates tested for ceftriaxone, 183 (75.9%) were resistant. Of 92 Gram-negative isolates tested for the extended spectrum beta-lactamase (ESBL) positive phenotype, 66 (71.7%) were ESBL positive phenotype. Transfer from another facility, recent surgery or antibiotic exposure, and hospital-acquired infection were each associated with resistance. Mortality was 19.6% for all enrolled participants.

CONCLUSIONS

This is the first published prospective hospital-wide antibiogram of multiple specimen types from East Africa with ESBL testing. Our study suggests that low-resource settings with limited and inconsistent access to the full range of antibiotic classes may bear the highest burden of resistant infections. Hospital-acquired infections and recent antibiotic exposure are associated with a high proportion of resistant infections. Efforts to slow the development of resistance and supply effective antibiotics are urgently needed.

Comparative Epidemiology and Resistance Trends of Common Urinary Pathogens in a Tertiary-Care Hospital: A 10-Year Surveillance Study

Background and Objective: Urinary tract infections (UTIs) are common in human medicine, affecting large patient populations worldwide. The principal cause of UTIs is uropathogenic Escherichia coli (UPEC) and Klebsiella, both in community and nosocomial settings. The assessment of local data on prevalence and resistance is essential to evaluate trends over time and to reflect on the national situation, compared to international data, using the methods of analytical epidemiology. Materials and Methods: The aim of this study was to assess resistance trends and epidemiology of UTIs caused by E. coli and Klebsiella species in inpatients and outpatients at a tertiary-care hospital in Hungary, using microbiological data. To evaluate resistance trends, several antibiotics were chosen as indicator drugs, based on local utilization data. Results: E. coli was the most prevalent isolate, representing 56.75 ± 4.86% for outpatients and 42.29 ± 2.94% for inpatients. For E. coli, the ratio of resistant strains for several antibiotics was significantly higher in the inpatient group, while in Klebsiella, similar trends were only observed for gentamicin. Extended-spectrum β-lactamase (ESBL)-producing isolates were detected in 4.33-9.15% and 23.22-34.22% from outpatient, 8.85-38.97% and 10.89-36.06% from inpatient samples for E. coli and Klebsiella, respectively. Conclusions: Resistance developments in common UTI pathogens (especially to fosfomycin, sulfamethoxazole-trimethoprim, fluoroquinolones, and 3rd generation cephalosporins), seriously curb therapeutic options, especially in outpatient settings.