Streptococcus pneumoniae carriage, serotypes, genotypes, and antimicrobial resistance trends among children in Portugal, after introduction of PCV13 in National Immunization Program: A cross-sectional study.

Streptococcus pneumoniae carriage studies are crucial to monitor changes induced by use of pneumococcal conjugate vaccines and inform vaccination policies. In this cross-sectional study, we examined changes within the pneumococcal population following introduction of PCV13 in 2015 in the National Immunization Program (NIP), in Portugal. In 2018-2020 (NIP-PCV13), we obtained 1450 nasopharyngeal samples from children ≤6 years attending day-care.

Impact of human created environments in the pathogenic potential and antimicrobial resistance of staphylococci from wild neotropical primates in Brazil.

The non-human primate (NHP) Leontopithecus rosalia is an endangered species native of Brazil and lives in forest fragments with different levels of contact with humans (natural, private and urban). Other NHPs - Callithrix spp. - were introduced by humans and co-exist and interact with the native species in these forests.

Molecular Epidemiologic and Geo-Spatial Characterization of Cultured from Skin and Soft Tissue Infections from United States-Born and Immigrant Patients Living in New York City.

(1) Background: With increasing international travel and mass population displacement due to war, famine, climate change, and immigration, pathogens, such as (), can also spread across borders. Methicillin-resistant (MRSA) most commonly causes skin and soft tissue infections (SSTIs), as well as more invasive infections. One clonal strain, USA300, originating in the United States, has spread worldwide.

Clonal Changes in the Pneumococcal Population Carried by Portuguese Children during Six Years of Private Use of the 13-Valent Pneumococcal Conjugate Vaccine: the Relative Contribution of Clonal Expansion, Clonal Emergence, and Capsular Switch Events.

In Portugal, the 13-valent pneumococcal conjugate vaccine (PCV13) was available for private use from 2010 to 2015 and it was introduced in the National Immunization Program in 2015. We have reported that private use of PCV13 led to extensive serotype replacement and an increase in antimicrobial susceptibility among pneumococci carried by healthy children. We investigated which clonal changes concurred with these observations.

Spontaneous Genomic Variation as a Survival Strategy of Nosocomial Staphylococcus haemolyticus.

Staphylococcus haemolyticus is one of the most important nosocomial human pathogens frequently isolated in bloodstream and medical device-related infections. However, its mechanisms of evolution and adaptation are still poorly explored. To characterize the strategies of genetic and phenotypic diversity in , we analyzed an invasive strain for genetic and phenotypic stability after serial passage in the absence and presence of beta-lactam antibiotics.

Frequent dissemination and carriage of an SCCmec-mecC hybrid in methicillin-resistant Mammaliicoccus sciuri in farm animals from Tunisia.

Objectives: In this study, we aimed to assess the extent of dissemination of methicillin-resistant Mammaliicoccus sciuri in animal farms in Tunisia and evaluate the distribution of virulence and methicillin resistance genes in the M. sciuri population.

Methods: Staphylococci and mammaliicocci isolated from unhealthy animals and healthy humans from adjacent farms in Tunisia were characterized for antimicrobial susceptibility, biofilm formation, agglutination, and hemolysis abilities.

Analysis of a Cell Wall Mutant Highlights Rho-Dependent Genome Amplification Events in Staphylococcus aureus.

In a study of antibiotic resistance in Staphylococcus aureus, specific cell wall mutants were previously generated for the peptidoglycan biosynthesis gene , by the insertion of an integrative plasmid. A collection of 30 independent mutants was obtained, and all harbored a variable number of copies of the inserted plasmid, arranged in tandem in the chromosome. Of the 30 mutants, only 3, F9, F20 and F26, with a lower number of plasmid copies, showed an altered peptidoglycan structure, lower resistance to β-lactams and a different loss-of-function mutation in gene, that encodes a transcription termination factor.

Evaluation of Methicillin-Resistant Carriage in the Elderly in Portugal Using Selective Enrichment Followed by Quantitative Real-Time PCR.

The prevalence of methicillin-resistant (MRSA) in hospitals in Portugal is worrisome and among the highest in Europe. Surprisingly, MRSA prevalence in the community was described as very low (<2%) based on studies that used classical culture-based methods (CCBM). We investigated whether the apparent limited spread of MRSA in the community in Portugal might result from low sensitivity of CCBM.

Impact of the Stringent Stress Response on the Expression of Methicillin Resistance in Strains Carrying , and .

The acquisition of the resistance determinant by is of major clinical importance, since it confers a resistant phenotype to virtually the entire large family of structurally diverse β-lactam antibiotics. While the common resistance determinant is essential, the optimal expression of the resistance phenotype also requires additional factors. Previous studies showed that the great majority of clinical isolates of methicillin-resistant (MRSA) have a heterogeneous resistant phenotype, and we observed that strains carrying methicillin genetic determinants other than also produce similar heterogeneous phenotypes.

Comparative Effectiveness Study of Home-Based Interventions to Prevent CA-MRSA Infection Recurrence.

Recurrent skin and soft tissue infections (SSTI) caused by Community-Associated Methicillin-Resistant (CA-MRSA) or Methicillin-Sensitive (CA-MSSA) present treatment challenges. This community-based trial examined the effectiveness of an evidence-based intervention (CDC Guidelines, topical decolonization, surface decontamination) to reduce SSTI recurrence, mitigate household contamination/transmission, and improve patient-reported outcomes. Participants (n = 186) were individuals with confirmed MRSA(+)/MSSA(+) SSTIs and their household members.

The role of interspecies recombination in the evolution of antibiotic-resistant pneumococci.

Multidrug-resistant emerge through the modification of core genome loci by interspecies homologous recombinations, and acquisition of gene cassettes. Both occurred in the otherwise contrasting histories of the antibiotic-resistant lineages PMEN3 and PMEN9. A single PMEN3 clade spread globally, evading vaccine-induced immunity through frequent serotype switching, whereas locally circulating PMEN9 clades independently gained resistance.

Absence of methicillin-resistant Staphylococcus aureus colonization among immunocompetent healthy adults: Insights from a longitudinal study.

Methicillin-resistant Staphylococcus aureus (MRSA) has long been known as a major cause of hospital-acquired (HA-MRSA) infections worldwide. For the past twenty years, an increasing number of studies have described its emergence in the community as well. In Portugal, a country with a high-prevalence of HA-MRSA, there are only limited data available on the epidemiology of MRSA in the community.

Impact of private use of the 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal carriage among Portuguese children living in urban and rural regions.

In Portugal, the 13-valent pneumococcal conjugate vaccine (PCV13) was commercially available between 2010 and 2015, following a decade of private use of PCV7. We evaluated changes on serotype distribution and antimicrobial susceptibility of pneumococci carried by children living in two regions of Portugal (one urban and one rural). Three epidemiological periods were defined: pre-PCV13 (2009-2010), early-PCV13 (2011-2012), and late-PCV13 (2015-2016).

From Clinical and Environmental Origins Have Distinct Biofilm Composition.

Biofilm formation has been shown to be critical to the success of uropathogens. Although is a common cause of urinary tract infections, its biofilm production capacity, composition, genetic basis, and origin are poorly understood. We investigated biofilm formation in a large and diverse collection of ( = 422).

Staphylococcus saprophyticus Causing Infections in Humans Is Associated with High Resistance to Heavy Metals.

Staphylococcus saprophyticus is a common pathogen of the urinary tract, a heavy metal-rich environment, but information regarding its heavy metal resistance is unknown. We investigated 422 S. saprophyticus isolates from human infection and colonization/contamination, animals, and environmental sources for resistance to copper, zinc, arsenic, and cadmium using the agar dilution method.

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.

Evidence for the Dissemination to Humans of Methicillin-Resistant ST398 through the Pork Production Chain: A Study in a Portuguese Slaughterhouse.

Livestock-associated methicillin-resistant (LA-MRSA) ST398 was recovered from infections in humans exposed to animals, raising public health concerns. However, contact with food producing chain as a means of transmission of LA-MRSA to humans remains poorly understood. We aimed to assess if pork production chain is a source of MRSA ST398 for human colonization and infection.

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.

Dynamics of Pneumococcal Carriage in Adults: A New Look at an Old Paradigm.

Background: Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches.

Methods: Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal.

Evaluation of Topical Lysostaphin as a Novel Treatment for Instrumented Rhesus Macaques () Infected with Methicillin-Resistant .

Lytic enzymes are novel antimicrobial agents that degrade bacterial cell walls, resulting in cell rupture and death. We tested one enzyme, the bacteriocin lysostaphin, for treatment of nonhuman primates () with persistent methicillinresistant (MRSA) infection of their cranial implant margins. The goal of this study was to determine if topical lysostaphin, either alone or as an adjunct therapy, could eliminate MRSA.