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Ricardo Dias

Publications and source records attributed to Ricardo Dias.

10 recordsLinked to original sources
PubMed2026

Detection of TR34/L98H pan-azole-resistant Aspergillus fumigatus in poultry farm environments.

INTRODUCTION: Poultry farms have been recognized as environments prone to fungal contamination. However, the occurrence of azole-resistant Aspergillus fumigatus and its cytotoxic potential remain insufficiently characterized. This study aimed to characterize the occurrence, cytotoxic potential, and azole-resistance profile ofAspergillus section Fumigati in poultry farms. METHODS: A total of 420 samples, including air (n = 47), electrostatic dust cloths (n = 87), bedding (n = 87), feed (n = 95), swabs (n = 87), workers' masks (n = 2), and broiler breast (n = 15), were obtained. Fungal characterization was performed through culture-based methods (27 °C and 37 °C), followed by azole resistance screening according to EUCAST guidelines. Resistant isolates were subjected to whole-genome sequencing and a targeted analysis of cyp51A mutations. The cytotoxicity potential of fungal isolates and environmental samples was evaluated using selected cell lines representing respiratory organs (human alveolar [A549]) and detoxification organs (swinekidney [SK]/hepatocellular carcinoma [HepG2]). RESULTS: Seven putative Aspergillus fumigatus isolates exhibited pan-azole resistance (MICs: ≥ 2 mg/L ITR/VOR; ≥ 1mg/L for POS). Four isolates carried the TR34/L98H mutation and were recovered from bedding (n = 3) and air (n = 1), suggesting the presence of resistant A. fumigatus in poultry farm matrices. Although 12% of isolates induced toxicity on both cell lines (17/145), no significant association was observed between isolate cytotoxicity and environmental sample toxicity, suggesting that additional biological and chemical components may contribute to the overall toxicological profile of farm environments. DISCUSION: The study highlights the occurrence of azole-resistant A. fumigatus in poultry farms and support integrated surveillance approaches addressing antifungal resistance and environmental exposure risks in poultry production.

Aspergillus fumigatus↗
PubMed2006

Antimicrobial susceptibility of invasive Streptococcus pneumoniae isolates in Portugal over an 11-year period.

This national surveillance study presents the in vitro activities of the main antimicrobial agents against 1,331 S. pneumoniae isolates as tested by an agar dilution method according to the guidelines of the Clinical and Laboratory Standards Institute (formerly NCCLS). The strains were isolated in several regions of Portugal from cases of invasive disease over an 11-year period (1994 to 2004). This study shows that the percentage of penicillin-nonsusceptible strains increased from 12% in 1994 to 28.5% in 2000. Then the rate declined to 17.7% in 2003 but increased again to 23.2% in 2004. Nevertheless, the rate of highly resistant isolates declined consistently, to 0.9% in 2001 to 2004. Ceftriaxone- and cefotaxime-nonsusceptible isolates became less frequent, from 4% and 8%, respectively, in 1994 to < or =1% in 2004. The macrolide-lincosamide-streptogramin B phenotype was the predominant macrolide phenotype found. The increase in the percentage of isolates that were only nonsusceptible to erythromycin (3.7% in 1994 to 1998 to 9.1% in 2002 to 2004) was similar to that for isolates with coresistance to penicillin and erythromycin (3.3% in 1994 to 1998 to 9.1% in 2002 to 2004). The nonsusceptibility to ciprofloxacin increased during recent years, from 0.5% in 2002 to 3.5% in 2004. Multidrug resistance also increased in recent years: from 7.9% in 2002 to 15.6% in 2004. The increasing use of macrolides could be causing the increase in penicillin and multidrug resistance, due to the coresistance to macrolides. The use of penicillin to treat empirical invasive pneumococci infections may need to be reconsidered.

Anti-Bacterial Agents↗
PubMed2006

Acute aortic dissection during pregnancy.

Acute aortic dissection is one of the most dreaded clinical conditions during pregnancy. Difficulties in establishing a diagnosis and limitations regarding invasive studies increase mortality rates associated with the disease. The limited experience reported in the literature does not allow the determination of guidelines for clinical and/or surgical management of aortic dissection in pregnancy. The authors present a case of acute aortic dissection in a woman in her 33rd week of gestation and discuss the diagnostic approach considering the peculiarities of the diseases manifestation.

Acute Disease↗
PubMed2004

Emergence of invasive erythromycin-resistant Streptococcus pneumoniae strains in Portugal: contribution and phylogenetic relatedness of serotype 14.

OBJECTIVES: To study the phenotype and phylogenetic relatedness of invasive Streptococcus pneumoniae strains isolated in Portugal. METHODS: A total of 614 invasive S. pneumoniae strains, isolated in Portugal from 1999 to the first 6 months of 2002, were characterized using serotyping and antimicrobial susceptibility testing. National outpatient sale data for macrolides were compared with erythromycin resistance. We investigated the main clonal lineages from erythromycin-resistant strains of serotype 14 by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: The emergence of erythromycin-resistant strains correlated well with the usage of azithromycin in Portugal during the period of the study (r=0.900, P=0.001). Serotype 14 made the largest contribution to this emergence. We found two clonal complexes (CC) among erythromycin-resistant strains: CC1 was formed by three sequence types (ST), ST156, ST143 and ST1042, and CC2 by ST15 and ST9. All STs described, except ST1042, are putative founders of clonal groups or subgroups from serotype 14 as defined in the pneumococcal MLST database. CONCLUSIONS: This study suggests that macrolides usage is an important factor enhancing the spread of invasive erythromycin-resistant S. pneumoniae clones in Portugal. The study also makes a contribution to the understanding of spread of erythromycin-resistant clones in an international context.

Anti-Bacterial Agents↗
PubMed2004

Invasive culture-confirmed Neisseria meningitidis in Portugal: evaluation of serogroups in relation to different variables and antimicrobial susceptibility (2000-2001).

The first investigation of Neisseria meningitidis isolated from a large area covering an appreciable population in Portugal, before the voluntary vaccination period with the serogroup C conjugate vaccine, is reported. The serogroups and antimicrobial susceptibility of 116 isolates were studied. Serogroups C (50.0 %), B (47.4 %) and W135 (2.6 %) were found. Serogroup C was most common in the 1-15-years-old group and B in the less than 1-year-old and over 16-years-old groups (P = 0.042). Clinical diagnosis of meningococcal disease was primarily meningitis for patients with serogroup C and meningitis associated with sepsis for those with serogroup B. Penicillin resistance was significantly associated with serogroup C (P < 0.001). This work reinforces the importance for public health of monitoring the serogroup and antimicrobial susceptibility of isolates from patients with invasive meningococcal disease.

Adolescent↗
PubMed2004

Neisseria meningitidis C:2b:P1.2,5 with intermediate resistance to penicillin, Portugal.

For 1 year, serogroup, serotype, serosubtype, and penicillin susceptibility of meningococci circulating in various regions in Portugal were evaluated. Most frequent phenotypes were B:4:P1.15 (13.4%) and C:2b:P1.2,5 (75.9%), which are also common in Spain. Overall, 27.5% of C:2b:P1.2,5 strains showed intermediate resistance to penicillin. Laboratory-based surveillance of meningococcal infection in Portugal provides important information to assess the adequacy of public health measures.

Humans↗
PubMed2003

Risk factors for the nasopharyngeal carriage of respiratory pathogens by Portuguese children: phenotype and antimicrobial susceptibility of Haemophilus influenzae and Streptococcus pneumoniae.

Between 1997 and 2000 nasopharyngeal specimens were obtained from 466 children < or = 12 years old attending the Pediatric Emergency Department at S. Francisco Xavier Hospital, Lisbon, to evaluate risk factors for nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae and to characterize their phenotype and antimicrobial susceptibility. The attending pediatrician completed written questionnaires about the children's demographic and clinical histories. Over half the children (52.8%) carried H. influenzae and/or S. pneumoniae. Forty-one percent of these children had H. influenzae, 22.8% had S. pneumoniae and 36.2% had both. Risk factors identified for carriage of respiratory pathogens were: age below 3 years (p < 0.05), black race (p < 0.01), attending a daycare center (p < 0.05), and having a lower respiratory infection (p < 0.05). Asthmatic children were less likely to be carriers (p = 0.004). About two-thirds of H. influenzae isolates were susceptible to all antibiotics tested, 7.9% were beta-lactamase producers, 16.4% were nonsusceptible to trimethoprim, and 6.9% were intermediately resistant to clarithromycin. Over half (57.1%) of S. pneumoniae isolates were susceptible to all antibiotics tested, 21.1% were multiresistant, 23.3% were nonsusceptible to penicillin, and about 20% were resistant to macrolides. Low-level resistance to third-generation cephalosporins was detected in 2.3%. The data reflect the controversy surrounding risk factors of nasopharyngeal colonization. These may have significant implications on clinical practice and on antimicrobial strategies to prevent the appearance of further resistant strains. Our findings highlight the importance to investigate the relationship between asthma and carriage.

Anti-Bacterial Agents↗
PubMed2003

Two major Spanish clones of penicillin-resistant Streptococcus pneumoniae in Portuguese isolates of clinical origin.

We studied the genetic relatedness of 47 Portuguese penicillin-resistant 9V and 23F Streptococcus pneumoniae of clinical origin, using pulsed-field gel electrophoresis (PFGE) and restriction fragment length polymorphism analysis. PFGE fingerprinting showed that 24 isolates of serotype 9V and 23 isolates of serotype 23F were variants of the Spain(9V)-3 and Spain(23F)-1 clones, respectively. Fingerprinting of pbp1a, pbp2b and pbp2x genes showed that all the penicillin-resistant clones gave similar HinfI restriction patterns. In this study, serotypes 9V and 23F have different clonal origins and identical PBP genotypes, suggesting a horizontal transfer of resistance. Visual and computer-assisted analysis of PFGE patterns correlated well (r = 0.983).

Aminoacyltransferases↗