Elmano Ramalheira

Methicillin-resistant Staphylococcus aureus carrying the new mecC gene--a meta-analysis.

In 2011, a new mecA gene homolog, named mecC gene, was found in isolates from both humans and animals. The discovery of methicillin-resistant Staphylococcus aureus (MRSA) carrying the mecC gene has caused speculations about the origin, epidemiology, and impact of these isolates. The objective of this work is to perform a meta-analysis on the prevalence of mecC MRSA, based on previously published results. Meta-analysis showed that the overall pooled prevalence is 0.009% (95% confidence interval=0.05-0.013) and that there was evidence of heterogeneity (P<0.01, I(2)=97%). In conclusion, the very low reported prevalence provides an important baseline to monitor the epidemiology of this emerging form of MRSA.

Clinical characteristics of patients with community-acquired complicated intra-abdominal infections: a prospective, multicentre, observational study

In this prospective, observational, multicentre study using data from five countries (Columbia, The Philippines, Portugal, Taiwan and Thailand), the clinical impact of extended-spectrum β-lactamase (ESBL)-producing organisms on hospitalised patients with community-acquired complicated intra-abdominal infections (CA-cIAIs) was compared with that of non-ESBL-producing organisms during the period April 2010 to December 2011. Adult patients (aged ≥18 years) requiring surgery or percutaneous drainage were enrolled and were followed during the first hospitalisation course. An unadjusted statistical comparison of risk factors for ESBL-positive and ESBL-negative patients was performed. Multivariate regression analyses were performed to assess whether length of stay (LOS) in hospital, clinical cure rate and some important clinical characteristics were associated with ESBL positivity. During the study period, a total of 105 adult patients from five countries were enrolled, of whom 17 (16.2%) had CA-cIAI due to ESBL-positive organisms and 88 (83.8%) had CA-cIAI due to ESBL-negative organisms. Escherichia coli was isolated in 73.3% of all samples. Infections were cured in 8 (47.1%) of the patients with CA-cIAI due to ESBL-positive organisms and in 59 (67.0%) of the patients with CA-cIAI due to ESBL-negative organisms (P=0.285). The median LOS was 11.6 days for patients with infections due to ESBL-negative organisms and 17.6 days for patients with infections due to ESBL-positive organisms (P=0.011). Multivariate logistic regression analysis revealed that pre-existing co-morbidities, but not ESBL positivity, were adversely associated with clinical cure of CA-cIAIs. In contrast, duration of hospitalisation was longer for patients with CA-cIAI due to ESBL-positive organisms.

Carriage of qnrA1 and qnrB2, blaCTX-M15, and complex class 1 integron in a clinical multiresistant Citrobacter freundii isolate.

A multiresistant Citrobacter freundii strain was recovered from a catheter from a patient hospitalized in Aveiro, Portugal. This strain harbored quinolone resistance genes, qnrA1 and qnrB2, both in a large plasmid.

First description of klebsiella pneumoniae clinical isolates carrying both qnrA and qnrB genes in Portugal

In the present study, 21 multidrug-resistant Klebsiella pneumoniae isolates were recovered from patients hospitalised in the Intensive Care Unit of Hospital Infante D. Pedro in Aveiro, Portugal. Fifteen isolates carried qnr genes. Four strains harboured the quinolone resistance genes qnrA and qnrB, both located on a large plasmid in two strains (KP4 and KP10) and on different plasmids in two strains (KP5 and KP6). These findings indicate an extremely high prevalence of qnr genes associated with various mobile elements such as ISCR1 and class 1 integrons.

mcr-1 and blaKPC-3 in Escherichia coli Sequence Type 744 after Meropenem and Colistin Therapy, Portugal

Escherichia coli Ec36 was recovered from a patient in Portugal after treatment with meropenem and colistin. Besides an IncF plasmid with Tn1441d-blaKPC-3, already reported in clinical strains in this country, E. coli Ec36 co-harbored an IncX4::mcr-1 gene. Results highlight emerging co-resistance to carbapenems and polymyxins after therapy with drugs from both classes.

A novel complex class 1 integron found in a Klebsiella pneumoniae isolate from Portugal.

Klebsiella pneumoniae Kp1 carrying a novel complex class 1 integron was isolated from an inanimate surface of a female ward sanitary facility in the Hospital Infante D. Pedro, Aveiro, central Portugal. The integron consists of two variable regions (VRs); VR1 was previously described in Escherichia coli and Vibrio cholerae, and VR2 contains an In37-like structure and is located downstream of an ISCR1 element. The integron was found on a plasmid of 225 kb. The qnrB10 gene, although present, is not associated with the complex class 1 integron.

Proteomic profile of susceptible and multidrug-resistant clinical isolates of Escherichia coli and Klebsiella pneumoniae using label-free and immunoproteomic strategies

Infectious diseases caused by multidrug-resistant (MDR) Enterobacteriaceae have exponentially increased in the past decade, and are a major concern in hospitals. In the first part of the work, we compared the proteome profile of MDR and susceptible clinical isolates of Escherichia coli and Klebsiella pneumoniae in order to identify possible biological processes associated with drug resistance and susceptible phenotypes, using a label-free approach. In the second part, we used an immunoproteomics approach to identify immunoreactive proteins in the same isolates. A total of 388 and 377 proteins were identified in MDR and susceptible E. coli, respectively, evidencing that biological processes related to translation are upregulated in E. coli MDR, while there is an upregulation of processes related to catalytic activity in K. pneumoniae MDR. Both MDR strains show downregulation of processes related to amino acid activation and tRNA amino-acylation. Our data also suggest that MDR strains have higher immunoreactivity than the susceptible strains. The application of high-throughput mass spectrometry (MS) and bioinformatics to the study of modulation of biological processes might shed light on the characterization of multidrug resistance in bacteria.

Genetically unrelated multidrug- and carbapenem-resistant Citrobacter freundii detected in outpatients admitted to a Portuguese hospital

OBJECTIVES Non-clonal, carbapenem- and multidrug-resistant Citrobacter freundii isolates were collected from unrelated outpatients admitted to a Portuguese hospital emergency department. One patient lived in a nursing home and was never hospitalised, whereas the other patient was repeatedly hospitalised in this hospital. The aim of this study was to unveil the molecular mechanisms associated with the carbapenem resistance of these isolates and to assess its potential dissemination. METHODS Isolate identification was performed by VITEK®2 and was confirmed by 16S rDNA sequencing. The clonal relationship of the isolates was evaluated by repetitive element palindromic PCR (rep-PCR). Antibiotic susceptibility was determined using the automatic VITEK®2 AES system and disk diffusion assay. β-Lactamases, porins and mobile genetic elements were characterised by PCR and sequencing. Pulsed-field gel electrophoresis (PFGE) and Southern blot hybridisation were used to determine the genetic location of integrons, and their transferability was tested by conjugation. RESULTS No genetic relatedness was found, suggesting different origins of the isolates. In isolate Cf254 a VIM-2 carbapenemase integrated in In58 was detected, located in a high-frequency conjugative IncL/M plasmid that also carried CTX-M-15 and CMY-39 genes. VIM-1 in isolate Cf872 was chromosomal. This is the first description in Portugal of VIM carbapenemases in C. freundii. Loss/alteration of porins was also detected. CONCLUSIONS Emergence of carbapenem-resistant Enterobacteria is not confined to the nosocomial environment. Community-acquired strains appear to be in circulation between inpatients and outpatients, spreading carbapenem resistance genes by horizontal gene transfer.