First three Escherichia coli isolates harbouring mcr-1 in Uruguay.

OBJECTIVE: This report described the first Escherichia coli (E. coli) isolates harbouring mcr-1 in Uruguay. METHODS: Three E. coli isolates were obtained from blood, urine and rectal swabs from different patients in two hospitals. Extended-spectrum ß-lactamases (ESBL), plasmid-encoded (pAmpC) ß-lactamases, plasmid-mediated quinolone resistance (PMQR) genes, class 1 integrons, and mcr-1, mcr-2 and mcr-3 were sought and characterised in three E. coli isolates. Transfer of resistance determinants was assessed by conjugation. Clonality was analysed by multilocus sequence typing. RESULTS: All isolates were categorised as being colistin-resistant and the mcr-1 gene was detected. Two isolates were also resistant to oxyimino cephalosporins: one on account of blaCMY-2 and the other due to blaCTX-M-15, the latter also harbouring transferable quinolone-resistance genes (aac(6')Ib-cr and qnrB). All mcr-1 genes were transferred by conjugation to recipient strains. The mcr-1-bearing isolates belonged to sequence types ST10, ST93 and ST5442. CONCLUSIONS: ST10 is considered as a high-risk clone worldwide. This type of mcr-1-harbouring clone is a major concern for human and animal health and must be under close surveillance. This study detected the presence of mcr-1 for the first time in Uruguay, albeit in an allodemic manner, associated with different antibiotic-resistance genes and from diverse clinical contexts. Considering that colistin is often the last therapeutic option available for multidrug-resistant Gram-negative bacilli infections, it is important to maximise precautions to avoid dissemination of isolates carrying mcr-1.

Three-year multicenter surveillance of community-acquired Listeria monocytogenes meningitis in adults.

BACKGROUND: Listeria monocytogenes is the third most frequent cause of bacterial meningitis. The aim of this study is to know the incidence and risk factors associated with development of acute community-acquired Lm meningitis in adult patients and to evaluate the clinical features, management, and outcome in this prospective case series. METHODS: A descriptive, prospective, and multicentric study carried out in 9 hospitals in the Spanish Network for Research in Infectious Diseases (REIPI) over a 39-month period. All adults patients admitted to the participating hospitals with the diagnosis of acute community-acquired bacterial meningitis (Ac-ABM) were included in this study. All these cases were diagnosed on the basis of a compatible clinical picture and a positive cerebrospinal fluid (CSF) culture or blood culture. The patients were followed up until death or discharge from hospital. RESULTS: Two hundred and seventy-eight patients with Ac-ABM were included. Forty-six episodes of Lm meningitis were identified in 46 adult patients. In the multivariate analysis only age (OR 1.026; 95% CI 1.00-1.05; p = 0.042), immunosuppression (OR 2.520; 95% CI 1.05-6.00; p = 0.037), and CSF/blood glucose ratio (OR 39.42; 95% CI 4.01-387.50; p = 0.002) were independently associated with a Lm meningitis. The classic triad of fever, neck stiffness and altered mental status was present in 21 (49%) patients, 32% had focal neurological findings at presentation, 12% presented cerebellum dysfunction, and 9% had seizures. Twenty-nine (68%) patients were immunocompromised. Empirical antimicrobial therapy was intravenous ampicillin for 34 (79%) of 43 patients, in 11 (32%) of them associated to aminoglycosides. Definitive ampicillin plus gentamicin therapy was significantly associated with unfavourable outcome (67% vs 28%; p = 0.024) and a higher mortality (67% vs 32%; p = 0.040).The mortality rate was 28% (12 of 43 patients) and 5 of 31 (16.1%) surviving patients developed adverse clinical outcome. CONCLUSIONS: Elderly or immunocompromised patients, and a higher CSF/blood glucose ratio in patients with Ac-ABM must alert clinicians about Lm aetiology. Furthermore, we observed a high incidence of acute community-acquired Lm meningitis in adults and the addition of aminoglycosides to treatment should be avoid in order to improve the patients' outcome. Nevertheless, despite developments in intensive care and antimicrobial therapy, this entity is still a serious disease that carries high morbidity and mortality rates.