Virulence attributes of successful methicillin-resistant lineages.

Methicillin-resistant (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology.

Plasmid-mediated fosfomycin resistance in Escherichia coli isolates of worldwide origin.

Objectives: Fosfomycin is a first-line treatment for uncomplicated urinary tract infections (UTIs) in several European countries, and it is increasingly becoming the treatment of choice globally. Resistance to fosfomycin in Escherichia coli can be exerted through several mechanisms, including the acquisition of fosfomycin-modifying enzymes, of which the FosA-type enzymes are the most common. This study analysed, both phenotypically and genotypically, an international collection of E.

Rapid culture-based LNZ test for detection of linezolid susceptibility/resistance in staphylococci and enterococci.

A rapid, easy-to-handle, cost-effective and universal culture-based test was developed for the identification of linezolid resistance among the most clinically relevant enterococcal and staphylococcal species. Our technique was tested using linezolid-resistant (n = 50) and linezolid-susceptible (n = 67) Gram-positive isolates: 34 Enterococcus faecium, 20 Enterococcus faecalis, 20 Staphylococcus aureus, 38 Staphylococcus epidermidis, and 5 Staphylococcus capitis. The susceptibility/resistance phenotype of E.

Occurrence of plasmid-mediated fosfomycin resistance (fos genes) among Escherichia coli isolates, Portugal.

Objectives: To evaluate the occurrence of plasmid-mediated fos genes among fosfomycin-resistant Escherichia coli isolates collected from patients in Lisbon, Portugal, and characterize the fos-positive strains.

Methods: A total of 19 186 E. coli isolates were prospectively collected between April 2022 and January 2023 from inpatients and outpatients at a private laboratory in Lisbon.

ESBL- and Carbapenemase-Producing and among Bivalves from Portuguese Shellfish Production Areas.

Bivalves are filter-feeding organisms and biomarkers of bacterial pollution. Our study aimed to analyze the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing among bivalves. A total of 522 bivalve samples were collected along Portuguese shellfish production areas.

Multiplex PCR for detection of acquired plasmid-borne fosfomycin resistance fos genes in Escherichia coli.

A rapid (<3 hours) and reliable multiplex PCR was developed for detecting simultaneously known plasmid-mediated fos genes conferring acquired resistance to fosfomycin. Our technique was tested on a collection of Escherichia coli isolates previously identified as bearing the fosA-, fosC- and fosL-like genes, showing a sensitivity and a specificity of 100%.

Urban Pigeons () as a Source of Broad-Spectrum β-Lactamase-Producing in Lisbon, Portugal.

Wild birds may be healthy carriers, and therefore, may be involved in the dissemination of clinically relevant antimicrobial-resistant bacteria, such as extended-spectrum β-lactamases (ESBL) and carbapenemase-producing . This study evaluated whether urban pigeons living in five spots in Lisbon, Portugal, may be colonized and, therefore, constitute potential spreaders of multidrug-resistant bacteria. A total of 100 pigeon fecal samples were collected in different urban areas for the detection of ESBL- or carbapenemase-producing .

Screening and Characterization of Multidrug-Resistant among Hospitalized Patients in the African Archipelago of Cape Verde.

This study aimed to investigate, for the first time, the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)- and carbapenemase-producing in Cape Verde. A total of 98 inpatients hospitalized at Hospital Universitário Agostinho Neto were screened for rectal colonization. All ESBL- and carbapenemase-producing isolates were tested for antimicrobial susceptibility and characterized by multilocus sequence typing.

Prevalence of biocide resistance genes and chlorhexidine and mupirocin non-susceptibility in Portuguese hospitals during a 31-year period (1985-2016).

Objectives: Methicillin-resistantStaphylococcus aureus (MRSA) remains a major human pathogen. MRSA decolonisation strategies frequently combine chlorhexidine baths and mupirocin nasal ointment. Although MRSA remains widespread in Portuguese hospitals, information regarding resistance to biocides and mupirocin is scarce.

High Colonization Rate and Heterogeneity of ESBL- and Carbapenemase-Producing Isolated from Gull Feces in Lisbon, Portugal.

In order to evaluate whether seagulls living on the Lisbon coastline, Portugal, might be colonized and consequently represent potential spreaders of multidrug-resistant bacteria, a total of 88 gull fecal samples were screened for detection of extended-spectrum β-lactamase (ESBL)- or carbapenemase-producing for methicillin-resistant (MRSA) and for vancomycin-resistant Enterococci (VRE). A large proportion of samples yielded carbapenemase- or ESBL-producing (16% and 55%, respectively), while only two MRSA and two VRE were detected. Mating-out assays followed by PCR and whole-plasmid sequencing allowed to identify carbapenemase and ESBL encoding genes.

Epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae among healthcare students, at the Portuguese Red Cross Health School of Lisbon, Portugal.

Objective: The aim of the present study was to prospectively evaluate the prevalence of intestinal carriage by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae among Portuguese students attending a Bachelors' course in healthcare, and to determine the molecular features of ESBL-producing isolates.

Methods: One-hundred and eleven faecal samples recovered from Portuguese healthcare students were screened for either ESBL-producing, carbapenem-resistant, colistin-resistant or pan-aminoglycoside-resistant Enterobacteriaceae, using respective screening media. All recovered isolates were tested for antimicrobial susceptibility and characterised by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

A five-year retrospective study shows increasing rates of antimicrobial drug resistance in Cabo Verde for both Staphylococcus aureus and Escherichia coli.

Objectives: Data on baseline drug resistance important in informing future antimicrobial stewardship programs. So far, no data on the antimicrobial drug resistance of clinical isolates available for the African archipelago of Cabo Verde.

Methods: We performed a retrospective analysis over years (2013-17) of the drug susceptibility profiles of clinical isolates in the two main hospitals of Cabo Verde.

Epidemiology of carbapenemase-producing Klebsiella pneumoniae in northern Portugal: Predominance of KPC-2 and OXA-48.

Objectives: To provide, for the first time, data on the molecular epidemiology of carbapenemase-producing Klebsiella pneumoniae clinical isolates from the northern region of Portugal (Trás-os-Montes and Alto Douro).

Methods: A total of 106 carbapenemase-producing K. pneumoniae isolates recovered from clinical samples and rectal swabs between January 2018 and March 2019 were included in this study.

Occurrence of NDM-1-producing Morganella morganii and Proteus mirabilis in a single patient in Portugal: probable in vivo transfer by conjugation.

Objectives: To decipher the genetics of acquisition of carbapenemase-encoding genes identified in two carbapenem-resistant Enterobacteriaceae recovered from a single patient in Portugal.

Methods: Carbapenemase genes were searched by PCR assays and mating-out assays were performed to further characterize the plasmid support of the carbapenemase genes. Genetic characterization of the plasmid supports was performed by whole-plasmid sequencing using the Illumina technology.

Intestinal carriage of extended-spectrum beta-lactamase-producing Enterobacteriaceae at admission in a Portuguese hospital.

To evaluate the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae fecal carriers at admission in a Portuguese hospital and to determine the epidemiology and antimicrobial resistance patterns of ESBL-producing isolates. During a 2-month period, rectal swabs were collected at hospital admission from 151 at-risk patients. In addition, 48 rectal swabs were obtained from weekly screenings of 37 patients hospitalized for > 48 h.

Epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus isolates colonizing pigs with different exposure to antibiotics.

Background: In 2016, very high rates of methicillin-resistant Staphylococcus aureus (MRSA)-ST398 (99%) were found in Portuguese pig farms that used colistin, amoxicillin, and zinc oxide as feed additives. Since then, farms A and B banned the use of colistin, and farm C banned the use of both antibiotics.

Objective: The aim of the present study was to evaluate the impact of the ban of colistin and amoxicillin on pig MRSA carriage rates, clonal types and antimicrobial resistance, compared to the results obtained in 2016.

CTX-M-33, a CTX-M-15 derivative conferring reduced susceptibility to carbapenems.

CTX-M-type extended-spectrum ß-lactamases (ESBL) are widespread among Enterobacterales worldwide. The most common variant is CTX-M-15 hydrolyzing ceftazidime at high rate, but sparing carbapenems. We identified here CTX-M-33, a point mutant derivative of CTX-M-15 (Asp to Ser substitution at Ambler position 109), exhibiting a low carbapenemase activity.

Occurrence of CTX-M-15- and MCR-1-producing Enterobacterales in pigs in Portugal: Evidence of direct links with antibiotic selective pressure.

Aims: To undertake a prospective analysis of the occurrence of colistin-resistant and extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales colonizing pigs at two farms in Portugal, and to evaluate the putative correlations with usage of different antibiotics.

Materials And Methods: One hundred and two faecal samples recovered from two different Portuguese pig farms were screened for polymyxin-resistant and ESBL-positive Enterobacterales. The authors had undertaken a study at one of the farms previously, but the use of colistin has since been banned; zinc oxide and amoxicillin are used as prophylactic and curative drugs, respectively, at this farm.

Epidemiology of Carbapenemase-Producing Klebsiella pneumoniae in a Hospital, Portugal.

We aimed to provide updated epidemiologic data on carbapenem-resistant Klebsiella pneumoniae in Portugal by characterizing all isolates (N = 46) recovered during 2013-2018 in a 123-bed hospital in Lisbon. We identified bla (n = 36), bla (n = 9), and bla (n = 8) carbapenemase genes and observed co-occurrence of bla and bla in 7 isolates. A single GES-5-producing isolate co-produced the extended-spectrum β-lactamase BEL-1; both corresponding genes were co-located on the same ColE1-like plasmid.

Staphylococcus aureus nasal carriage among homeless population in Lisbon, Portugal.

Methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage is a major risk factor for infection, namely among populations in the community with inherent prompting factors, such as the homeless. In Portugal, there are no data on S. aureus/MRSA nasal carriage among the homeless community.

Novel coating containing molybdenum oxide nanoparticles to reduce Staphylococcus aureus contamination on inanimate surfaces.

We previously synthetized molybdenum oxide (MoO3) nanoparticles (NP) and showed their antibacterial activity against a representative collection of the most relevant bacterial species responsible for hospital-acquired infections, including Staphylococcus aureus. The aim of the present study was to prepare and characterize a novel coating with these MoO3 NP, confirm its mechanical stability, and investigate its biocidal effect to reduce S. aureus contamination on inanimate surfaces.

Screening and Characterization of Multidrug-Resistant Gram-Negative Bacteria from a Remote African Area, São Tomé and Príncipe.

The occurrence of resistance to last-resort antibiotics was evaluated among isolates recovered from hospitalized children in a remote African archipelago, São Tomé and Príncipe, where there is limited access to those antibiotics. Fifty patients were screened for colonization by carbapenem-, pan-aminoglycoside-, or polymyxin-resistant A total of 36 isolates (including 30 and 4 ) were recovered from 23 patients, including 26 isolates harboring the carbapenemase gene, a single isolate harboring the 16S rRNA methylase gene encoding pan-resistance to aminoglycosides, and 8 isolates coharboring both genes. A single isolate possessed the plasmid-borne colistin resistance gene A high clonal relationship was found for OXA-181-producing (4 clones), and conversely, three of the four OXA-181-producing isolates were clonally unrelated.

Evaluation of Different Screening Methodologies for the Detection of Methicillin-Resistant Staphylococcus aureus from Environmental Surfaces: Swabs, Gauzes, and Polywipes.

Methicillin-resistant Staphylococcus aureus (MRSA) can survive for long periods on inanimate objects, and therefore, environmental surfaces constitute an important reservoir for dissemination. However, there is no standardized method for the detection of MRSA from environmental surfaces. The aim of the present study was to evaluate different screening methods to detect environmental MRSA contamination.