Publications by authors named "Claudio Marcos Rocha de Souza"

Pseudomonas aeruginosa, an opportunistic pathogen often found in Healthcare-associated infections (HAI), has shown increased resistance to carbapenems (imipenem, meropenem, doripenem), the primary treatment options. We've seen a rise in carbapenemase-producing P. aeruginosa in Brazil, including NDM-producers.

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  • Enterobacter cloacae complex is a significant multidrug-resistant pathogen found in hospitals, prompting a study on its antimicrobial resistance and genetic factors in Brazil.
  • The study screened 94 clinical isolates, finding 20.2% (19 isolates) resistant to colistin, with high levels of resistance indicated by MIC values ranging from 4 to 128 µg/mL.
  • Genetic analysis revealed several carbapenemase and polymyxin resistance genes, along with diverse genetic profiles among the isolates, but no predominant clone was established.
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Introduction: contributes significantly to the global issue of multidrug-resistant (MDR) nosocomial infections. Often, these strains demonstrate resistance to carbapenems (MDR-CRAB), the first-line treatment for infections instigated by MDR . Our study focused on the antimicrobial susceptibility and genomic sequences related to plasmids from 12 clinical isolates of that carry both the blaOXA-58 and carbapenemase genes.

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  • Carbapenemase production is a significant global health concern, and analyzing antimicrobial resistance (AMR) data is essential for effective public health policies, as showcased in this study focused on Brazil's AMR Surveillance Network.
  • The study evaluated carbapenemase detection rates in Brazilian hospitals from 2015 to 2022, finding trends such as a notable increase in blaNDM detection and a decrease in blaKPC for Enterobacterales, particularly after the onset of the COVID-19 pandemic.
  • Overall, the findings highlight the resilience of the AMR Surveillance Network and indicate a concerning shift in carbapenemase profiles, with blaNDM becoming increasingly prevalent.
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  • A recent outbreak of polymyxin-carbapenem-resistant Klebsiella pneumoniae (PCR-Kp) in Rio de Janeiro highlighted the emergence of untreatable infections, necessitating hospital-wide surveillance since December 2014.
  • Whole-genome sequencing revealed similarities and differences in genetic traits linked to resistance and virulence among the bacteria, with 10% of tested cases showing a concerning drug-resistant profile.
  • The study emphasizes the need for further research to understand the connection between bacterial genetics and clinical outcomes, particularly in patients with existing health issues and limited treatment options.
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Bacterial nasal colonization is common in many mammals and Staphylococcus represents the main pathogen isolated. Staphylococcus nasal carriage in humans constitutes a risk factor for Staphylococcus infections pointing out the need for animal experimentation for nasal colonization studies, especially for vaccine development. A limitation in addressing this hypothesis has been a lack of appropriate animal model.

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  • Carbapenems are crucial last-resort antibiotics for treating infections from multidrug-resistant Gram-negative bacteria, but resistance through mechanisms like OprD loss and carbapenemases is a growing global concern.
  • A study in Brazil tested the effectiveness of three phenotypic tests—Carba NP, Blue Carba, and mCIM/eCIM—to detect carbapenemase-producing Pseudomonas species, using 127 clinical isolates.
  • Results showed that Carba NP had the highest sensitivity and successfully differentiated between carbapenemases types, while Blue Carba struggled with class B detection, highlighting the need for improved and more reliable resistance detection methods.
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  • - The study assessed 502 Enterobacteriales isolates in Brazil for resistance to polymyxins, specifically colistin, revealing a 29.5% resistance rate and confirming all isolates as multidrug-resistant (MDR).
  • - Genetic analysis indicated that 77% of isolates harbored carbapenemase genes, with various molecular typing methods identifying significant diversity, including 51 pulsotypes and 21 sequence types (STs), notably ST437, ST258, and ST11.
  • - The research identified key chromosomal mutations and insertion sequences linked to increased resistance, highlighting the emergence of high-risk clones such as CC11 in Brazil, raising concerns about global implications for antibiotic resistance.
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Due to recent developments in NGS technologies, genome sequencing is generating large volumes of new data containing a wealth of biological information. Understanding sequenced genomes in a biologically meaningful way and delineating their functional and metabolic landscapes is a first-level challenge. Considering the global antimicrobial resistance (AMR) problem, investments to expand surveillance and improve existing genome analysis technologies are pressing.

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  • High rates of carbapenem resistance in Brazilian Pseudomonas aeruginosa are linked to a specific clone (ST277) that produces a type of carbapenemase called SPM-1.
  • Researchers used whole genome sequencing to analyze the genetic make-up of a plasmid containing the bla gene in these resistant isolates and found a new bla-plasmid.
  • The study highlights the urgent need for public health measures to track the spread of this plasmid due to its connection with a high-risk bacterial clone.
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  • Multidrug-resistant gram-negative bacilli (GNB) are a significant global health issue, especially when linked to bloodstream infections (BSI), which worsen patient outcomes.
  • Whole-genome sequencing was used to study these pathogens in Brazil, revealing high-risk clones like CC258, ST79, and ST233, along with their resistance mechanisms.
  • Key findings included associations between specific gene variants and clones, the identification of new MDR clone ST3079, and a novel clonal profile ST848, which could inform future strategies for managing BSI and other hospital-acquired infections.
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  • - Emergence of colistin-resistant bacteria with mobile resistance genes is a growing threat to both animals and humans involved in food production.
  • - The article focuses on identifying a specific plasmid that carries colistin resistance genes in poultry, highlighting its role as a new reservoir for these genes.
  • - Three closely related bacterial strains were isolated from cloacal swabs, and their genomes included a significant plasmid that potentially facilitates the spread of colistin resistance.
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  • The Brazilian clone of Pseudomonas aeruginosa, ST277, shows significant antibiotic resistance, particularly due to the SPM-1 carbapenemase gene, and is mainly found in Brazil.
  • A phylogenetic analysis revealed that Brazilian ST277 strains have unique genetic markers and a typical set of resistance and virulence features, as well as a high frequency of the CRISPR-Cas system type I-C.
  • The study concludes that distinct genetic components in Brazilian P. aeruginosa ST277 strains contribute to their resistance and pathogenic traits, differentiating them from strains in other regions like Asia, Europe, and North America.
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  • KPC-producing bacteria have emerged as a significant public health concern, particularly as previous colonization is a key risk factor for developing infections.
  • A study analyzed 102 KPC- isolates from human rectal swabs across Brazil to understand their genetic and antimicrobial resistance profiles between 2009-2013.
  • Results showed these isolates were largely resistant to various antibiotics but susceptible to a few, with many belonging to a specific genetic lineage (clonal complex 258), indicating a strong link between colonization and infection in patients.
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  • * A study in Rio de Janeiro analyzed 88 P. aeruginosa isolates from 1995 to 2015, revealing a shift from earlier MDR strains to more resistant extensive drug-resistant (XDR) strains in recent years, particularly with increased resistance to critical antibiotics.
  • * Key resistance mechanisms identified included mutations in specific genes and the presence of carbapenemase genes, indicating a growing threat from high-risk clones of P. aeruginosa in the region.
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  • Polymyxins are used as a last-resort treatment for infections caused by resistant Gram-negative bacteria, specifically targeting Klebsiella pneumoniae in this study.
  • The study analyzed 97 strains of K. pneumoniae for resistance mechanisms, identifying key β-lactamase genes and mutations in the pmrB gene associated with polymyxin resistance.
  • Findings show high prevalence of specific resistance genes and confirm that mutations in pmrB, particularly T157P, are significant in developing resistance among the K. pneumoniae strains in Brazilian public hospitals.
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New Delhi metallo-β-lactamase (NDM)-producing bacteria have been identified at a worrying rate in Brazil since 2013. Owing to the need to understand the extent of their spread, this study reports the dissemination of bla in different species of Gram-negative bacilli in different regions and states of Brazil. A total of 81 isolates from nine states were studied, including 11 species.

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Streptococcus pneumoniae is a colonizer of the human nasopharynx, which accounts for most of the community-acquired pneumonia cases and can cause non-invasive and invasive diseases. Current available vaccines are serotype-specific and the use of recombinant proteins associated with virulence is an alternative to compose vaccines and to overcome these problems. In a previous work, we describe the identification of proteins in S.

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Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. Equine leptospirosis is commonly manifested by recurrent uveitis, reproductive disorders, as abortions, embryonic absorption, stillbirth and the birth of weak foals. The aim of this study was to verify the presence of Leptospira sp or its DNA in genital tract of mares with reproductive problems.

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Although infection by Corynebacterium diphtheriae is a model of extracellular mucosal pathogenesis, different clones have been also associated with invasive infections such as sepsis, endocarditis, septic arthritis and osteomyelitis. The mechanisms that promote C. diphtheriae infection and haematogenic dissemination need further investigation.

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