RESUMEN

Aztreonam-avibactam, eravacycline, and cefoselis are three novel antimicrobial agents for the treatment of serious infections caused by Gram-negative bacteria. We evaluated the in vitro activities of the above-mentioned three antimicrobial agents against clinical Enterobacterales isolates. A total of 1,202 Enterobacterales isolates, including 10 genera or species, were collected from 26 hospitals that cover seven regions of China. The susceptibilities of the 30 antimicrobial agents were interpreted based on the combination of U.S. Food and Drug Administration and Clinical and Laboratory Standards Institute guidelines. The results indicated that all Enterobacterales isolates showed high susceptibility to aztreonam-avibactam (98.25%), eravacycline (85.69%), and cefoselis (62.73%). The first two antimicrobial agents also demonstrated potent activities against multidrug-resistant and carbapenem-resistant Enterobacterales independent of antimicrobial resistance mechanisms. The rates of susceptibility to aztreonam-avibactam, eravacycline, and cefoselis were lowest in Morganella spp. (84.42%), Proteus spp. (33.65%), and Escherichia coli (40.14%), respectively. In general, the lower rates of susceptibility to eravacycline and cefoselis were in the older inpatient group. The strains isolated from urinary tract exhibited the lowest rate of susceptibility (78.97%) to eravacycline, and the lowest rate of susceptibility (45.83%) to cefoselis was observed in nervous system specimens. The strains isolated from intensive care unit (ICU) wards showed significantly reduced susceptibility to cefoselis compared with those isolated from non-ICU wards. The MIC values of aztreonam-avibactam and ceftazidime-avibactam have poor consistency (weighted kappa = 0.243), as did eravacycline and tigecycline (weighted kappa = 0.478). Cefoselis and cefepime showed highly similar activities against Enterobacterales (weighted kappa = 0.801). Our results support the clinical development of aztreonam-avibactam, eravacycline, and cefoselis to treat infections caused by Enterobacterales. IMPORTANCE Infections caused by multidrug-resistant (MDR) Enterobacterales, especially carbapenem-resistant Enterobacterales (CRE), have been a challenging clinical problem due to the limited therapeutic options. Therefore, the need to develop novel antimicrobial agents and evaluate their activities against Enterobacterales in vitro is urgent. Our results show that the novel antimicrobial agents aztreonam-avibactam and eravacycline retain activities against MDR and CRE isolates, including carbapenemase producers and non-carbapenemase producers. Further analysis combined with clinical information on the strains tested revealed that no significant differences were observed in susceptibility rates of strains with different demographic parameters to aztreonam-avibactam. Age, specimen source, and department were associated with the susceptibility of strains to eravacycline and cefoselis (P ≤ 0.01). Compared with ceftazidime-avibactam, aztreonam-avibactam has its advantages and limitations against Enterobacterales. The potent activity of eravacycline against Enterobacterales was higher than that of tigecycline. Cefoselis and cefepime showed a highly consistent activity against Enterobacterales.

Asunto(s)

Antibacterianos , Aztreonam , Aztreonam/farmacología , Aztreonam/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Tigeciclina , Cefepima , beta-Lactamasas , Carbapenémicos , Pruebas de Sensibilidad Microbiana

RESUMEN

Although the prevalence of carbapenem-resistant Enterobacterales remains low in Japan, these bacteria are a growing problem worldwide, owing to their multidrug resistance phenotype. We isolated a multidrug-resistant Providencia rettgeri strain, NR1418, harboring a rare blaIMP variant, blaIMP-70, a novel blaCTX-M variant, designated blaCTX-M-253, and blaMOX-1. This strain is resistant to ß-lactams, amikacin, levofloxacin, and colistin. Genomic analysis revealed that NR1418 carries two plasmids, designated pNR1418-1 and pNR1418-2. The pNR1418-1 plasmid harbors blaCTX-M-253, blaTEM-1, and blaMOX-1, while the pNR1418-2 plasmid harbors blaIMP-70, which is located in a class 1 integron. Both plasmids exhibit high similarities with the plasmid of the P. rettgeri isolate BML2526, which also harbors blaIMP-70 and was identified in the same region of Japan as NR1418 at a different point in time. This indicates the possibility of the emergence and evolution of IMP-70-producing P. rettgeri and suggests that the plasmid of BML2526 may have occurred following recombination of the two plasmids harbored by NR1418. Further, blaIMP-70 and blaCTX-M-253 were found on unique plasmids, indicating that they likely evolved through mutations and recombination. IMPORTANCE Although Providencia rettgeri is an opportunistic pathogen, its intrinsic resistance to colistin and tigecycline makes the treatment of carbapenem-resistant P. rettgeri challenging. We isolated a multidrug-resistant P. rettgeri strain which harbored a rare blaIMP variant, blaIMP-70, a novel blaCTX-M variant, blaCTX-M-253, and blaMOX-1 from a urinary sample obtained in Osaka, Japan. We investigated its genetic structure and evaluated the evolution of the plasmids carrying these genes. We show that blaIMP-70, blaCTX-M-253, and blaMOX-1 are present on unique plasmids and that they have high similarities to the plasmid of another IMP-70-producing P. rettgeri isolate that was identified as being from the same location. The evolution of plasmids through mutations and recombination may play a role in the development and spread of multidrug resistance.

Asunto(s)

beta-Lactamasas , Antibacterianos/farmacología , beta-Lactamasas/genética , Carbapenémicos , Colistina , Pruebas de Sensibilidad Microbiana , Plásmidos/genética , Providencia

RESUMEN

Duodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

Asunto(s)

Duodenoscopios/normas , Contaminación de Equipos/prevención & control , Equipo Reutilizado/estadística & datos numéricos , Control de Infecciones/métodos , Control de Infecciones/normas , Antibacterianos/farmacología , Infección Hospitalaria/prevención & control , Desinfección/economía , Desinfección/legislación & jurisprudencia , Desinfección/métodos , Farmacorresistencia Bacteriana Múltiple , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/patogenicidad , Infecciones por Enterobacteriaceae/prevención & control , Infecciones por Enterobacteriaceae/transmisión , Equipo Reutilizado/normas , Humanos , Control de Infecciones/economía , Control de Infecciones/legislación & jurisprudencia , Estados Unidos , United States Food and Drug Administration/legislación & jurisprudencia

RESUMEN

BACKGROUND: Antimicrobial resistance is increased by international mobility. We present data about intestinal colonization of travelers departing from a middle-income country. METHODS: Travelers were recruited from 2015 to 2019, collected an anal stool specimen and answered a questionnaire before and after travel. Enterobacterales isolates were investigated for antimicrobial resistance; extended-spectrum beta-lactamase (ESBL) and carbapenemase production; plasmid-encoded cephalosporinases (pAmpC), plasmid-mediated quinolone resistance (PMQR) and mcr genes by PCR and sequencing; and association with travel related variables. RESULTS: Among 210 travelers, 26 (12%) carried multidrug-resistant Enterobacterales (MDR-E) and 18 (9%) ESBL-producing Enterobacterales (ESBL-E) before travel, with an increased prevalence from 1% to 11% over the study years. Acquisition of MDR-E and ESBL-E occurred in 59 (32%) and 43 (22%) travelers, respectively, mostly blaCTX-M-15 carrying Escherichia coli. One traveler acquired one isolate carrying blaOXA-181 gene, and two others, isolates carrying mcr-1. PMQR were detected in 14 isolates of returning travelers. The risk of MDR-E acquisition was higher in Southeast Asia and the Indian subcontinent, and after using antimicrobial agents. CONCLUSION: We describe an increasing pre-travel prevalence of ESBL-E colonization in subjects departing from this middle-income country over time. Travel to known risk areas and use of antimicrobial agents during travel were associated with acquisition of MDR-E. Travel advice is critical to mitigating this risk, as colonization by MDR-E may raise the chances of antimicrobial-resistant infections.

Asunto(s)

Antibacterianos , Viaje , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Brasil/epidemiología , Farmacorresistencia Bacteriana/genética , Humanos , Enfermedad Relacionada con los Viajes , beta-Lactamasas/genética

RESUMEN

OBJECTIVES: Dutch guidelines recommend contact precautions in patients with multidrug resistant microorganisms cultured during the previous 12 months. To evaluate this policy, duration of carriage of multidrug resistant Enterobacterales was assessed among discharged hospital patients and patients attending their general practitioner (GP). Additionally, we assessed factors associated with clearance. METHODS: From January 2013 until May 2016, rectal or faecal samples accompanied by questionnaires on patient characteristics were obtained at time of study inclusion and 3, 6 and 12 months later, in 72 patients with multidrug resistant Enterobacterales. Clearance was defined as one or more negative cultures without a subsequent positive culture at 12 months after study inclusion. The percentage of clearance, intermittent carriage and persistence was determined and associated factors were assessed by logistic regression analysis. RESULTS: Clearance was found in 31 patients (43.1% [95%CI: 32.3-54.6]) of which 23 patients had two or more subsequent negative cultures. Twelve patients were classified as intermittent carriers (16.7% [95%CI: 9.8-26.9]) and 29 patients (40.3% [95% CI: 29.7-51.8]) as persistent carriers. Of the intermittent carriers, the majority (n=9) had two negative cultures during the study period. There was no difference in clearance between discharged hospitalized patients and GP patients. The only factor associated with clearance at 12 months in both univariable and multivariable analyses was not traveling to a foreign country (OR=3.5 [95%CI: 1.0-12.4]). CONCLUSION: Active screening for clearance of multidrug resistant Enterobacterales in patients within the health care setting is probably not beneficial due to high levels of intermittent and persistent carriage.