6 research outputs found

    Multilocus sequencing typing as a tool to investigate childhood Haemophilus influenzae invasive disease in Portugal

    Get PDF
    Background: Haemophilus influenzae is an important cause of serious childhood invasive disease despite the use of the vaccine against serotype b strains (Hib). Six capsular types, a-f, have been identified to date, although most of strains are non-capsulated (NC). Multilocus Sequencing Typing (MLST) is a powerful method that allows a precise and unambiguous characterization of H. influenzae genotypes. A partnership between the National Institute of Health and the Society for Paediatric Infectious Diseases aimed to characterize invasive childhood infection in Portugal. The objective of this study was to genotype isolates by MLST to follow the epidemiology of disease. Material / Methods: This study was conducted between 1 January 2010 and 31 December 2015. During this period 41 H. influenzae strains were analysed, mostly isolated from blood (88%). Antibiotic resistance was assessed by the microdilution assay and β-lactamase production was determined with nitrocefin. Capsular status was characterized by polymerase chain reaction using primers and conditions described in the literature. MLST was performed by amplifying and sequencing internal fragments of the 7 housekeeping genes (adk, atpG, frdB, fucK, mdh, pgi and recA). Sequences were analyzed and submitted to the MLST website http://pubmlst.org/hinfluenzae/ for assignment of the sequence type (ST). To display the allelic distances between the obtained STs, we applied the goeBURST algorithm implemented in the PHYLOViZ platform. Results: Antimicrobial susceptibility testing showed that most strains were susceptible to all beta-lactams studied, with only three strains being ampicillin resistant due to beta-lactamase production. Most of invasive disease was due to the presence of NC strains (27/41; 66%), while 14 isolates (34%) were capsulated and characterized as follow: two serotype a (5%), 10 b (24%) and two f (5%). As expected, MLST typing revealed high genetic variability among 27 NC isolates, which had 24 (89%) different sequence types (STs), with four new STs represented by previously unidentified allele combinations. In opposition, capsulated isolates were very clonal: all 10 Hib were assigned to CC6 (eight strains ST6, one ST 1149, one ST 190), the two Hia strains were assigned to CC 23 (ST 23) and the two Hif belonged to CC124 (ST 124 and ST 1188) (Figure 1). Conclusions: Our data indicate that invasive disease among Portuguese children is now due to highly genetically diverse, fully susceptible NC strains, suggesting that no particular virulent clone is responsible for epidemiological change of disease, after vaccine implementation in the year 2000. Nevertheless, we are concerned about Hib disease (24% of the isolates) despite the higher vaccine coverage. MLST typing continues to show a high genetic diversity among NC strains and clonal relationships among capsulated isolates. In conclusion, in order to monitor the evolving dynamics of this pathogen and the epidemiology of invasive disease, ongoing surveillance is needed to monitor the true magnitude of this problem.info:eu-repo/semantics/publishedVersio

    Portuguese recommendations for the use of biological therapies in patients with axial spondyloarthritis - 2016 update

    Get PDF
    Objective: To update the recommendations for the treatment of axial spondyloarthritis (axSpA) with biological therapies, endorsed by the Portuguese Society of Rheumatology. Methods: These treatment recommendations were formulated by Portuguese rheumatologists based on lite - rature evidence and consensus opinion. At a national meeting, the recommendations included in this document were discussed and updated. A draft of the full text of the recommendations was then circulated and suggestions were incorporated. A final version was again circulated before publication and the level of agreement among Portuguese Rheumatologists was anonymously assessed using an online survey. Results: A consensus was achieved regarding the initiation, assessment of response and switching of biological therapies in patients with axSpA. In total, seven recommendations were produced. The first recommendation is a general statement indicating that biological therapy is not a first-line drug treatment option and should only be used after conventional treatment has failed. The second recommendation is also a ge - neral statement about the broad concept of axSpA adopted by these recommendations that includes both non-radiographic and radiographic axSpA. Recommendations 3 to 7 deal with the definition of active di - sease (including the recommended threshold of 2.1 for the Ankylosing Spondylitis Disease Activity Score [ASDAS] or the threshold of 4 [0-10 scale] for the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), conventional treatment failure (nonsteroidal anti-inflammatory drugs being the first-line drug treatment), assessment of response to treatment (based on an ASDAS improvement of at least 1.1 units or a BASDAI improvement of at least 2 units [0-10 scale] or at least 50%), and strategy in the presence of an ina - dequate response (where switching is recommended) or in the presence of long-term remission (where a process of biological therapy optimization can be consi - dered, either a gradual increase in the interval between doses or a decrease of each dose of the biological the - rapy). Conclusion: These recommendations may be used for guidance in deciding which patients with axSpA should be treated with biological therapies. They co - ver a rapidly evolving area of therapeutic intervention. As more evidence becomes available and more biological therapies are licensed, these recommendations will have to be updated

    Haemophilus influenzae invasive disease in children – preliminary results from the Portuguese Study Group

    No full text
    Introduction: Haemophilus influenzae (H. influenzae) can cause life-threatening infections especially in children. Although six capsular serotypes (a-f) have been identified to date, H. influenzae serotype b (Hib) has long been a major cause of morbidity and mortality. The Hib conjugate vaccine was introduced in the Portuguese Immunization Program in June 2000 and lead to a dramatically decrease of invasive disease. The National Reference Laboratory for Bacterial Respiratory Infections, based at the National Institute of Health in Lisbon, is the reference laboratory for H. influenzae. In the beginning of 2010, the Pediatric Infectious Disease Society and our Laboratory started a surveillance study on invasive H. influenzae infections in paediatric age, with the participation of 30 Hospitals all over Portugal. Material and Methods: From January 2010 to December 2012 we received 28 strains from patients under 18 years old. Twenty-four strains were isolated from blood, three from cerebrospinal fluid, and one from a net joint fluid. Twenty two isolates (78.6%) were from pre-school children (≤5 years old). Males accounted for 78.6% of the cases. β-lactamase production was determined with nitrocefin. Minimum inhibitory concentrations (MIC) was determined for 13 antibiotics by a microdilution assay, according to CLSI guidelines. Serotyping was performed by PCR. MLST was performed for strains isolated after 2011. Results and Discussion: Serotype characterization showed that the majority of the cases (75%) were due to non-capsulated strains (NC). Of the 7 capsulated strains, five were serotype b (two vaccine failures) and two serotypes a and f respectively. Two strains were β-lactamase producers (7.1%). All other strains were susceptible to all antibiotics tested, except for trimethoprim-sulfamethoxazole with 22.2% of resistance. According to other studies MLST also revealed a great diversity among NC strains: 8 different STs in 11 strains. Comparing the results of this surveillance with our first studies, in pre-vaccine era, we are facing a change in the epidemiology of H. influenzae invasive disease with NC, fully susceptible strains, being responsible for invasive disease in Portugal

    Mutations selected in HIV-2-infected patients failing a regimen including atazanavir

    No full text
    OBJECTIVES: To investigate mutations selected in viruses from HIV-2-infected patients failing a highly active antiretroviral treatment (HAART) regimen including atazanavir/ritonavir. METHODS: Twenty-eight HIV-2-infected patients previously exposed to atazanavir/ritonavir and failing therapy were studied. The protease (PR) gene was amplified and sequenced, and mutations emerging under atazanavir/ritonavir selective pressure were reported. RESULTS: The I50L mutation emerged in 4 out of 28 HIV-2-infected patients failing a HAART regimen including atazanavir/ritonavir. Besides I50L, four PR mutations previously associated with protease inhibitor resistance (I54L, I64V, V71I and I82F) and six PR mutations of unknown impact (V10I, E37D, S43T, K45R, I75V and F85L) in HIV-2 were also identified in this small group of patients. CONCLUSIONS: Several mutations were associated with virological failure of a regimen including atazanavir/ritonavir in HIV-2-infected patients, including I50L for the first time. It should be included in HIV-2 algorithms for interpretation of genotypic resistance data, and taken into account when making therapeutic decisions for HIV-2-infected patients.status: publishe

    Epidemiology and genetic variability of respiratory syncytial virus in Portugal, 2014-2018

    No full text
    Free PMC article: https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/31707201/Introduction: Respiratory syncytial virus (RSV) is associated with substantial morbidity and mortality since it is a predominant viral agent causing respiratory tract infections in infants, young children and the elderly. Considering the availability of the RSV vaccines in the coming years, molecular understanding in RSV is necessary. Objective: The objective of the present study was to describe RSV epidemiology and genotype variability in Portugal during the 2014/15-2017/18 period. Material and methods: Epidemiological data and RSV-positive samples from patients with a respiratory infection were collected through the non-sentinel and sentinel influenza surveillance system (ISS). RSV detection, subtyping in A and B, and sequencing of the second hypervariable region (HVR2) of G gene were performed by molecular methods. Phylogenetic trees were generated using the Neighbor-Joining method and p-distance model on MEGA 7.0. Results: RSV prevalence varied between the sentinel (2.5%, 97/3891) and the non-sentinel ISS (20.7%, 3138/16779), being higher (P < 0.0001) among children aged <5 years. Bronchiolitis (62.9%, 183/291) and influenza-like illness (24.6%, 14/57) were associated (P < 0.0001) with RSV laboratory confirmation among children aged <6 months and adults ≥65 years, respectively. The HVR2 was sequenced for 562 samples. RSV-A (46.4%, 261/562) and RSV-B (53.6%, 301/562) strains clustered mainly to ON1 (89.2%, 233/261) and BA9 (92%, 277/301) genotypes, respectively, although NA1 and BA10 were also present until 2015/2016. Conclusion: The sequence and phylogenetic analysis reflected the relatively high diversity of Portuguese RSV strains. BA9 and ON1 genotypes, which have been circulating in Portugal since 2010/2011 and 2011/2012 respectively, predominated during the whole study period.info:eu-repo/semantics/publishedVersio

    Appendix

    No full text
    corecore