Significant increase of CTX-M-15-ST131 and emergence of CTX-M-27-ST131 Escherichia coli high-risk clones causing healthcare-associated bacteraemia of urinary origin in Spain (ITUBRAS-2 project).

OBJECTIVES: To assess the microbiological characteristics of Escherichia coli causing healthcare-associated bacteraemia of urinary origin (HCA-BUO) in Spain (ITUBRAS-2 project), with particular focus on ESBL producers and isolates belonging to ST131 high-risk clone (HiRC). Clinical characteristics and outcomes associated with ST131 infection were investigated. METHODS: A total of 222 E. coli blood isolates were prospectively collected from patients with HCA-BUO from 12 tertiary-care hospitals in Spain (2017-19). Antimicrobial susceptibility and ESBL/carbapenemase production were determined. ST131 subtyping was performed. A subset of 115 isolates were selected for WGS to determine population structure, resistome and virulome. Clinical charts were reviewed. RESULTS: ESBL-producing E. coli prevalence was 30.6% (68/222). ST131 represented 29.7% (66/222) of E. coli isolates and accounted for the majority of ESBL producers (46/68, 67.6%). The C2/H30-Rx subclone accounted for most ST131 isolates (44/66) and was associated with CTX-M-15 (37/44) and OXA-1 enzymes (27/44). Cluster C1-M27 was identified in 4/10 isolates belonging to subclade C1/H30-R1 and associated with CTX-M-27. Additionally, ST131 isolates showed a high content of other acquired resistance genes, and clade C/ST131 isolates carried characteristic QRDR mutations. They were categorized as uropathogenic E. coli and had higher aggregate virulence scores. ST131 infection was associated with more complex patients, prior use of cephalosporins and inadequate empirical treatment but was not associated with worse clinical outcomes. CONCLUSIONS: ST131 HiRC is the main driver of ESBL-producing E. coli causing HCA-BUO in Spain, mainly associated with the expansion of subclade CTX-M-15-C2/H30-Rx and the emergence of CTX-M-27-C1/H30-R1 (Cluster C1-M27).

Antimicrobial susceptibility of microorganisms that cause urinary tract infections in pediatric patients.

INTRODUCTION: Cumulative susceptibility reports are a valuable tool for the empirical treatment of urinary tract infections, especially in the current context of increasing resistance rates. Our objective was to analyze the antimicrobial susceptibility of bacterial isolates in urine cultures of pediatric patients during a five-year period. METHODS: Retrospective study of urine cultures from 2011 to 2015. Identification and antimicrobial susceptibility tests were performed using the Vitek-2 system (BioMérieux®) and categorized according to EUCAST criteria. Antimicrobial susceptibility data were analyzed by gender and age groups (neonates, 1 month to 5 years, 5-15 years) before being compared with data obtained from patients over the age of 15 years. RESULTS: During the study period, 17164 urine cultures were processed from 7924 patients under 16 years of age. Antimicrobial susceptibility rates in these patients were: ampicillin 36.3%, amoxicillin/clavulanic acid 75.3%, cefuroxime 83.2%, co-trimoxazole 68.9%, ciprofloxacin 85.3%, fosfomycin 85.5%, nitrofurantoin 84.4% and 3rd generation cephalosporins 89-91%. Aminoglycosides (>92%) and carbapenems (95%) maintained the highest susceptibility rates. The prevalence of ESBL-producing isolates was significantly lower in children under the age of 16 years (1.5% vs. 4.1%). In patients under the age of 16 years, Escherichia coli isolates in girls were significantly more sensitive (p<0.0001) to ampicillin (41% vs. 30%) and amoxicillin/clavulanic acid (82% vs. 72%) than in boys. CONCLUSIONS: The compilation of cumulative susceptibility reports disaggregated by age or gender reveals significant differences. In our setting, cefuroxime may be considered the first-line empirical treatment in pediatric patients.

Meningitis Caused by Salmonella Newport in a Five-Year-Old Child.

Salmonella Newport is a Gram-negative bacillus belonging to the Enterobacteria family and the nontyphi Salmonella (NTS), usually related to gastroenteritis. Main difference between NTS and Salmonella typhi is that the last one evolves to an invasive disease easier than NTS. These can progress to bacteremias in around 5% of cases and secondary focuses can appear occasionally, as in meningitis. An infection of the central nervous system is uncommon, considering its incidence in 0.6-8% of the cases; most of them are described in developing countries and mainly in childhood, especially neonates. Bacterial meningitis by NTS mostly affects immunosuppressed people in Europe. Prognosis is adverse, with a 50% mortality rate, mainly due to complications of infection: hydrocephalus, ventriculitis, abscesses, subdural empyema, or stroke. Choice antibiotic treatments are cefotaxime, ceftriaxone, or ceftazidime. The aim of this paper is to present a case of meningitis caused by Salmonella Newport diagnosed in a five-year-old girl living in a rural area of the province of Ourense (Spain), with favorable evolution and without neurological disorders.