Emergence of methicillin-resistant Staphylococcus aureus (MRSA) RdJ clone (CC5-ST105-SCCmecII-t002) in Santa Catarina, Brazil.

The emergence of highly successful genetic lineages of methicillin-resistant Staphylococcus aureus (MRSA) poses a challenge in human healthcare due to increased morbidity and mortality rates. The RdJ clone (CC5-ST105-SCCmecII-t002 lineage), previously identified in Rio de Janeiro, Brazil, was linked to bloodstream infections and features a mutation in the aur gene (encoding aureolysin). Additionally, clinical isolates derived from this clone were more effective at evading monocytic immune responses. This study aimed to detect the RdJ clone among clinical MRSA isolated in Santa Catarina (SC) and examine its antimicrobial resistance and phagocytosis evasion capabilities. Our findings revealed the RdJ clone in 20 % of MRSA isolates, all exhibiting multiresistance. RdJ clone isolates from SC did not demonstrate a decreased rate of phagocytosis compared to CC5 non-RdJ isolates. Structural analysis suggests that the aur mutation is unlikely to significantly impact aureolysin activity. Genomic analysis of one isolate unveiled a genetic variant of the RdJ clone, sharing lineage and gene distribution but lacking the aur mutation. This study enhances the understanding of the clinical and epidemiologic risks associated with the RdJ clone and the biological mechanisms underlying its spreading in SC.

Stenotrophomonas maltophilia Belonging to Novel Sequence Types ST473 and ST474 in Wild Birds Inhabiting the Brazilian Amazonia.

Stenotrophomonas maltophilia is an opportunistic human pathogen associated with nosocomial and community-acquired infections. We have conducted a microbiological and genomic surveillance study of broad-spectrum cephalosporin- and carbapenem-resistant Gram-negative bacteria colonizing wild birds inhabiting the Brazilian Amazonia. Strikingly, two S. maltophilia strains (SM79 and SM115) were identified in Plain-throated antwren (Isleria hauxwelli) passerines affected by Amazonian fragmentation and degradation. Noteworthy, SM79 and SM115 strains belonged to new sequence types (STs) ST474 and ST473, respectively, displaying resistance to broad-spectrum ß-lactams, aminoglycosides and/or fluoroquinolones. In this regard, resistome analysis confirmed efflux pumps (smeABC, smeDEF, emrAB-tolC and macB), blaL1 and blaL2, aph(3')-IIc and aac(6')-Iak, and Smqnr resistance genes. Comparative phylogenomic analysis with publicly available S. maltophilia genomes clustered ST473 and ST474 with human strains, whereas the ST474 was also grouped with S. maltophilia strains isolated from water and poultry samples. In summary, we report two novel sequence types of S. maltophilia colonizing wild Amazonian birds. The presence of opportunistic multidrug-resistant pathogens in wild birds, from remotes areas, could represent an ecological problem since these animals could easily promote long-distance dispersal of medically important antimicrobial-resistant bacteria. Therefore, while our results could provide a baseline for future epidemiological genomic studies, considering the limited information regarding S. maltophilia circulating among wild animals, additional studies are necessary to evaluate the clinical impact and degree of pathogenicity of this human opportunistic pathogen in wild birds.

Genomic analysis of a Kpi (pilus system)-positive and CTX-M-15-producing Klebsiella pneumoniae belonging to the high-risk clone ST15 isolated from an impacted river in Brazil.

Convergence of resistance and virulence in Klebsiella pneumoniae is a critical public health issue worldwide. A multidrug-resistant CTX-M-15-producing K. pneumoniae (TIES-4900 strain) was isolated from a highly impacted urban river, in Brazil. The genome was sequenced by MiSeq Illumina platform and de novo assembled using Unicycler. In silico prediction was accomplished by bioinformatics tools. The size of the genome is 5.4 Mb with 5145 protein-coding genes. TIES-4900 strain belonged to the sequence type ST15, yersiniabactin sequence type YbST10, ICEKp4, KL24 (wzi-24) and O1v1 locus. Phylogenomics confirmed genomic relatedness with ST15 clones from human and animal hosts. Convergence of broad resistome (antibiotics, heavy-metals and biocides) and virulome, including the Kpi pilus system involved in host-pathogen interaction and persistence of ST15 clone to hospital environments, were predicted. Virulent behavior was confirmed in the Galleria mellonella infection model. This study may give genomic insights on the spread of critical-priority WHO pathogens beyond hospital settings.

Imported One-Day-Old Chicks as Trojan Horses for Multidrug-Resistant Priority Pathogens Harboring mcr-9, rmtG, and Extended-Spectrum ß-Lactamase Genes.

Antimicrobial resistance is a critical issue that is no longer restricted to hospital settings but also represents a growing problem involving intensive animal production systems. In this study, we performed a microbiological and molecular investigation of priority pathogens carrying transferable resistance genes to critical antimicrobials in 1-day-old chickens imported from Brazil to Uruguay. Bacterial identification was performed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, and antibiotic susceptibility was determined by Sensititre. Antimicrobial resistance genes were sought by PCR, and clonality was assessed by pulsed-field gel electrophoresis (PFGE). Four multidrug-resistant (MDR) representative strains were sequenced by an Illumina and/or Oxford Nanopore Technologies device. Twenty-eight MDR isolates were identified as Escherichia coli (n = 14), Enterobacter cloacae (n = 11), or Klebsiella pneumoniae (n = 3). While resistance to oxyiminocephalosporins was due to blaCTX-M-2, blaCTX-M-8, blaCTX-M-15, blaCTX-M-55, and blaCMY-2, plasmid-mediated quinolone resistance was associated with the qnrB19, qnrE1, and qnrB2 genes. Finally, resistance to aminoglycosides and fosfomycin was due to the presence of 16S rRNA methyltransferase rmtG and fosA-type genes, respectively. Short- and long-read genome sequencing of E. cloacae strain ODC_Eclo3 revealed the presence of IncQ/rmtG (pUR-EC3.1; 7,400 bp), IncHI2A/mcr-9.1/blaCTX-M-2 (pUR-EC3.2, ST16 [pMLST; 408,436 bp), and IncN2/qnrB19/aacC3/aph(3″)-Ib (pUR-EC3.3) resistance plasmids. Strikingly, the blaCTX-M-2 gene was carried by a novel Tn1696-like composite transposon designated Tn7337. In summary, we report that imported 1-day-old chicks can act as Trojan horses for the hidden spread of WHO critical-priority MDR pathogens harboring mcr-9, rmtG, and extended-spectrum ß-lactamase genes in poultry farms, which is a critical issue from a One Health perspective. IMPORTANCE Antimicrobial resistance is considered a significant problem for global health, including within the concept of One Health; therefore, the food chain connects human health and animal health directly. In this work, we searched for microorganisms resistant to antibiotics considered critical for human health in intestinal microbiota of 1-day-old baby chicks imported to Uruguay from Brazil. We describe genes for resistance to antibiotics whose use the WHO has indicated to "watch" or "reserve" (AWaRe classification), such as rmtG and mcr9.1, which confer resistance to all the aminoglycosides and colistin, respectively, among other genes, and their presence in new mobile genetic elements that favor its dissemination. The sustained entry of these microorganisms evades the sanitary measures implemented by the countries and production establishments to reduce the selection of resistant microorganisms. These silently imported resistant microorganisms could explain a considerable part of the antimicrobial resistance problems found in the production stages of the system.

Genomic features of mecA-positive methicillin-resistant Mammaliicoccus sciuri causing fatal infections in pets admitted to a veterinary intensive care unit.

Methicillin-resistant staphylococci have become leading cause of infectious diseases in humans and animals, being categorized as high priority pathogens by the World Health Organization. Although methicillin-resistant Staphylococcus sciuri (recently moved to Mammaliicoccus sciuri) has been widely reported in companion animals, there is scarce information regarding their clinical impact and genomic features. Herein, we reported the occurrence and genomic characteristics of methicillin-resistant M. sciuri recovered from fatal infections in pets admitted to an intensive care unit of a veterinary hospital, in Brazil. Two M. sciuri strains were isolated from bronchoalveolar lavage samples collected from dog (strain SS01) and cat (strain SS02) presenting with sepsis and acute respiratory distress syndrome. Both isolates displayed a multidrug-resistant profile, whereas whole-genome sequencing analysis confirmed the presence of the mecA gene, along to genetic determinant conferring resistance to macrolides, streptogramins, aminoglycosides, and trimethoprim. For both strains, the mec and crr gene complex shared high identity (≥97%) with analogue sequences from a M. sciuri isolated from a human wound infection, in the Czech Republic. Strains were assigned to the sequence type ST52 and the novel ST74. Phylogenomic analysis revealed a broad host range association of these strains with several hosts and sources, including humans, animals, food, and the environment through different years and geographic locations. Our findings demonstrate that infections caused by mecA-positive M. sciuri strains can be a serious threat for veterinary intensive care patients and the medical staff, with additional implications for One Health approaches.

Multidrug-resistant Klebsiella pneumoniae: a retrospective study in Manaus, Brazil.

Klebsiella pneumoniae is an opportunistic pathogen that can cause several infections, mainly in hospitalised or immunocompromised individuals. The spread of K. pneumoniae emerging virulent and multidrug-resistant clones is a worldwide concern and its identification is crucial to control these strains especially in hospitals. This article reports data related to multi-resistant K. pneumoniae strains, isolated from inpatients in the city of Manaus, Brazil, harbouring virulence and antimicrobial-resistance genes, including high-risk international clones belonging to clonal group (CG) 258. Twenty-one strains isolated from different patients admitted to four hospitals in the city of Manaus, located in the state of Amazonas, Northern Brazil (Amazon Rainforest region) were evaluated. The majority of strains (61.9% n = 13) were classified as multidrug-resistant (MDR), and five strains (23.8%) as extensively drug-resistant (XDR). Several virulence and antimicrobial-resistance genes were found among the strains and eight strains (38.1%) presented the hyper-mucoviscous phenotype. MLST analysis demonstrated a great diversity of STs among the strains, totaling 12 different STs (ST11, ST23, ST198, ST277, ST307, ST340, ST378, ST462, ST502, ST3991, ST3993 and ST5209). Three of these (ST11, ST23 and ST340) belong to CG258.

Unveiling the Virulent Genotype and Unusual Biochemical Behavior of Escherichia coli ST59.

Extraintestinal pathogenic Escherichia coli (ExPEC) is a leading cause of human and animal infections worldwide. The utilization of selective and differential media to facilitate the isolation and identification of E. coli from complex samples, such as water, food, sediment, and gut tissue, is common in epidemiological studies. During a surveillance study, we identified an E. coli strain isolated from human blood culture that displayed atypical light cream-colored colonies in chromogenic agar and was unable to produce ß-glucuronidase and ß-galactosidase in biochemical tests. Genomic analysis showed that the strain belongs to sequence type 59 (ST59) and phylogroup F. The evaluation in silico of 104 available sequenced lineages of ST59 complex showed that most of them belong to serotype O1:K1:H7, are ß-glucuronidase negative, and harbor a virulent genotype associated with the presence of important virulence markers such as pap, kpsE, chuA, fyuA, and yfcV. Most of them were isolated from extraintestinal human infections in diverse countries worldwide and could be clustered/subgrouped based on papAF allele analysis. Considering that all analyzed strains harbor a virulent genotype and most do not exhibit biochemical behavior typical of E. coli, we report that they could be misclassified or underestimated, especially in epidemiological studies where the screening criteria rely only on typical biochemical phenotypes, as happens when chromogenic media are used. IMPORTANCE The use of selective and differential media guides presumptive bacterial identification based on specific metabolic traits that are specific to each bacterial species. When a bacterial specimen displays an unusual phenotype in these media, this characteristic may lead to bacterial misidentification or a significant delay in its identification, putting a patient at risk depending on the infection type. In the present work, we describe a virulent E. coli sequence type (ST59) that does not produce beta-glucuronidase (GUS negative), production of which is the metabolic trait widely used for E. coli presumptive identification in diverse differential media. The recognition of this unusual metabolic trait may help in the proper identification of ST59 isolates, the identification of their reservoir, and the evaluation of the frequency of these pathogens in places where automatic identification methods are not available.

Genomic insights of international clones of Haemophilus influenzae causing invasive infections in vaccinated and unvaccinated infants.

The emergence of invasive Haemophilus influenzae infections in vaccinated patient is a public health concern. We have investigated the genomic basis of invasiveness and possible vaccine failure in H. influenzae causing invasive disease in vaccinated and unvaccinated children in Brazil. Three H. influenzae strains isolated from blood cultures of pediatric patients were sequenced. Serotype, MLST, resistome and virulome were predicted using bioinformatic tools, whereas single nucleotide polymorphisms (SNPs) analysis of cap loci and the presence of the putative virulence-enhancing IS1016-bexA partial deletion were predicted in silico. Infections were caused by H. influenzae type a (Hia), type b (Hib) and nontypeable (NTHi), belonging to international high-risk clones of sequence types ST23, ST6 and ST368, respectively, which have been identified in North American, European and Asian countries. Convergence of ampicillin resistance and virulence in Hib-ST6 was supported by blaTEM-1B and deletion in the bexA gene, whereas presence of SNPs in the cap-b locus was associated with antigenic modifications of the capsule structure. Hia-ST23 and NTHi-ST368 strains carried galU, lpsA, opsX, rfaF, iga1, lgtC and lic1/lic2 virulence genes, associated with colonization, adaptation and damage to the lung, or invasiveness. In summary, deletion in the bexA gene and presence of SNPs in the cap locus of Hib could be contributing to invasive disease and possible vaccine failure in pediatric patients, whereas serotype replacement of Hib with type "a" and NTHi strains denotes the ability of non-vaccine serotypes to re-colonize vaccinated patients. Finally, the dissemination of international high-risk clones of H. influenzae emphasizes the importance of monitoring changes in the molecular epidemiology of invasive H. influenzae disease.

Genomic data reveal international lineages of critical priority Escherichia coli harbouring wide resistome in Andean condors (Vultur gryphus Linnaeus, 1758).

Critical priority pathogens have globally disseminated beyond clinical settings, thereby threatening wildlife. Andean Condors (Vultur gryphus) are essential for ecosystem health and functioning, but their populations are globally near threatened and declining due to anthropogenic activities. During a microbiological and genomic surveillance study of critical priority antibiotic-resistant pathogens, we identified pandemic lineages of multidrug-resistant extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli colonizing Andean Condors admitted at two wildlife rehabilitation centres in South America. Genomic analysis revealed the presence of genes encoding resistance to hospital and healthcare agents among international E. coli clones belonging to sequence types (STs) ST162, ST602, ST1196 and ST1485. In this regard, the resistome included genes conferring resistance to clinically important cephalosporins (i.e., CTX-M-14, CTX-M-55 and CTX-M-65 ESBL genes), heavy metals (arsenic, mercury, lead, cadmium, copper, silver), pesticides (glyphosate) and domestic/hospital disinfectants, suggesting a link with anthropogenic environmental pollution. On the other hand, the presence of virulence factors, including the astA gene associated with outbreak of childhood diarrhoea and extra-intestinal disease in animals, was identified, whereas virulent behaviour was confirmed using the Galleria mellonella infection model. E. coli ST162, ST602, ST1196 and ST1485 have been previously identified in humans and food-producing animals worldwide, indicating that a wide resistome could contribute to rapid adaptation and dissemination of these clones at the human-animal-environment interface. Therefore, these results highlight that Andean Condors have been colonized by critical priority pathogens, becoming potential environmental reservoirs and/or vectors for dissemination of virulent and antimicrobial-resistant bacteria and/or their genes, in associated ecosystems and wildlife.

Ciprofloxacin-Mediated Mutagenesis Is Suppressed by Subinhibitory Concentrations of Amikacin in Pseudomonas aeruginosa.

Resistance to antibiotics is a global health problem. Activation of the SOS response, and the subsequent elevation in mutagenesis, contributes to the appearance of resistance mutations. Among currently used drugs, quinolones are the most potent inducers of the SOS response. In the present study, we show that amikacin inhibits ciprofloxacin-mediated SOS induction and mutagenesis in Pseudomonas aeruginosa.

Colistin-Resistant mcr-1-Positive Escherichia coli on Public Beaches, an Infectious Threat Emerging in Recreational Waters.

The emergence and rapid spread of colistin-resistant Escherichia coli carrying the mcr-1 gene have generated an urgent need to strengthen surveillance. We performed a meticulous investigation of strains of this sort, which resulted in the identification of international clones of E. coli carrying IncX4-plasmid-mediated mcr-1 and blaCTX-M genes in recreational waters of public urban beaches in cities with high tourist turnover, highlighting a new environmental reservoir.

Chicken Meat as a Reservoir of Colistin-Resistant Escherichia coli Strains Carrying mcr-1 Genes in South America.

The detection and rapid spread of colistin-resistant Enterobacteriaceae carrying the mcr-1 gene has created an urgent need to strengthen surveillance. In this study, eight clonally unrelated colistin-resistant Escherichia coli isolates carrying mcr-1 and blaCTX-M or blaCMY-2 genes were isolated from commercial chicken meat in Brazil. Most E. coli strains carried IncX4 plasmids, previously identified in human and animal isolates. These results highlight a new reservoir of mcr-1-harboring E. coli strains in South America.

Detection of Colistin-Resistant MCR-1-Positive Escherichia coli by Use of Assays Based on Inhibition by EDTA and Zeta Potential.

The emergence and rapid dissemination of colistin-resistant Escherichia coli carrying the plasmid-mediated mcr-1 gene have created an urgent need to develop specific screening methods. In this study, we evaluated four assays based on the inhibition of MCR-1 activity by EDTA: (i) a combined-disk test (CDT) comparing the inhibition zones of colistin and colistin (10 µg) plus EDTA (100 mM); (ii) reduction of colistin MIC (CMR) in the presence of EDTA (80 µg/ml); (iii) a modified rapid polymyxin Nordmann/Poirel test (MPNP); and (iv) alteration of zeta potential (RZP = ZP+EDTA/ZP-EDTA). We obtained encouraging results for the detection of MCR-1 in E. coli isolates recovered from human, food, and animal samples, using the following assay parameters: ≥3 mm difference in the inhibition zones between colistin disks without and with EDTA; ≥4-fold colistin MIC decrease in the presence of EDTA; RZP of ≥2.5; and the absence of metabolic activity and proliferation, indicated by unchanged color of phenol red in the presence of colistin-EDTA, in the MPNP test. In this regard, the CDT, CMR, RZP, and MPNP assays exhibited sensitivities of 96.7, 96.7, 95.1, and 96.7% and specificities of 89.6, 83.3, 100, and 100%, respectively, for detecting MCR-1-positive E. coli Our results demonstrate that inhibition by EDTA and zeta potential assays may provide simple and inexpensive methods for the presumptive detection of MCR-1-producing E. coli isolates in human and veterinary diagnostic laboratories.

First Report of the Globally Disseminated IncX4 Plasmid Carrying the mcr-1 Gene in a Colistin-Resistant Escherichia coli Sequence Type 101 Isolate from a Human Infection in Brazil.

A colistin-resistant Escherichia coli strain was recovered from a patient with a diabetic foot infection in Brazil. Whole-genome analysis revealed that the E. coli isolate belonged to the widespread sequence type (ST) 101 and harbored the mcr-1 gene on an IncX4 plasmid that was highly similar to mcr-1-bearing IncX4 plasmids that were recently identified in Enterobacteriaceae from food, animal, and human samples recovered on different continents. These results suggest that self-transmissible IncX4-type plasmids may represent promiscuous plasmids contributing to the intercontinental spread of the mcr-1 gene.

Silent dissemination of colistin-resistant Escherichia coli in South America could contribute to the global spread of the mcr-1 gene.

During a Brazilian multicentric antimicrobial resistance surveillance study, colistin resistance was investigated in 4,620 Enterobacteriaceae isolated from human, animal, food and environmental samples collected from 2000 to 2016. We present evidence that mcr-1-positive Escherichia coli has been emerging in South America since at least 2012, supporting a previous report on the possible acquisition of mcr-1-harbouring E. coli by European travellers visiting Latin American countries.

Hybrid genome assembly of colistin-resistant mcr-1.5-producing Escherichia coli ST354 reveals phylogenomic pattern associated with urinary tract infections in Brazil.

BACKGROUND: The rapid and global spread of Escherichia coli carrying mcr-type genes at the human-animal-environmental interface has become a serious global public health problem. OBJECTIVE: To perform a genomic investigation of a colistin-resistant E. coli strain (14005RM) causing urinary tract infection, using a hybrid de novo assembly of Illumina/Nanopore sequence data, presenting phylogenomic insights into the relationship with mcr-1-positive strains circulating at the human-animal-environmental interface, in Brazil. METHODS: Genomic DNA was sequenced using both the Illumina NexSeq and Nanopore MinION platforms. De novo hybrid assembly was performed by Unicycler. Genomic data were assessed by in silico prediction and bioinformatic tools. RESULTS: The genome assembly size was 5 333 039 bp. The mcr-1.5-positive E. coli strain 14005RM belongs to the sequence type ST354 and presented a broad resistome (antibiotics, heavy metals, disinfectants, and glyphosate) and virulome. The mcr-1.5 gene was carried by an IncI2 plasmid (p14005RM, sizing 65,458 kb). Full genome SNP-based phylogenetic analysis reveals that mcr-1.5-producing E. coli strain 14005RM is highly related (> 98% identity) to colistin-resistant mcr-1.1-positive ST354 lineages associated with urinary tract infections in Brazil since 2015. CONCLUSION: Mobile colistin resistance within the Brazilian One Health microbiosphere is mediated by mcr gene variants propagated by IncX4, IncHI2, and IncI2 plasmids, circulating among global clones of E. coli.