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Klebsiella aerogenes is an important opportunistic pathogen with the potential to develop resistance against last-line antibiotics, such as carbapenems, limiting the treatment options. Here, we investigated the antibiotic resistance profiles of 10 K. aerogenes strains isolated from patient samples in the intensive-care unit of a Brazilian tertiary hospital using conventional PCR and a comprehensive genomic characterization of a specific K. aerogenes strain (CRK317) carrying both the blaKPC-2 and blaNDM-1 genes simultaneously. All isolates were completely resistant to β-lactam antibiotics, including ertapenem, imipenem, and meropenem with differencing levels of resistance to aminoglycosides, quinolones, and tigecycline also observed. Half of the strains studied were classified as multidrug-resistant. The carbapenemase-producing isolates carried many genes of interest including: β-lactams (blaNDM-1, blaKPC-2, blaTEM-1, blaCTX-M-1 group, blaOXA-1 group and blaSHVvariants in 20-80% of the strains), aminoglycoside resistance genes [aac(6')-Ib and aph(3')-VI, 70 and 80%], a fluoroquinolone resistance gene (qnrS, 80%), a sulfonamide resistance gene (sul-2, 80%) and a multidrug efflux system transporter (mdtK, 70%) while all strains carried the efflux pumps Acr (subunit A) and tolC. Moreover, we performed a comprehensive genomic characterization of a specific K. aerogenes strain (CRK317) carrying both the blaKPC-2 and blaNDM-1 genes simultaneously. The draft genome assembly of the CRK317 had a total length of 5,462,831 bp and a GC content of 54.8%. The chromosome was found to contain many essential genes. In silico analysis identified many genes associated with resistance phenotypes, including β-lactamases (blaOXA-9, blaTEM-1, blaNDM-1, blaCTX-M-15, blaAmpC-1, blaAmpC-2), the bleomycin resistance gene (bleMBL), an erythromycin resistance methylase (ermC), aminoglycoside-modifying enzymes [aac(6')-Ib, aadA/ant(3")-Ia, aph(3')-VI], a sulfonamide resistance enzyme (sul-2), a chloramphenicol acetyltransferase (catA-like), a plasmidmediated quinolone resistance protein (qnrS1), a glutathione transferase (fosA), PEtN transferases (eptA, eptB) and a glycosyltransferase (arnT). We also detected 22 genomic islands, eight families of insertion sequences, two putative integrative and conjugative elements with a type IV secretion system, and eight prophage regions. This suggests the significant involvement of these genetic structures in the dissemination of antibiotic resistance. The results of our study show that the emergence of carbapenemase-producing K. aerogenes, coharboring blaKPC-2 and blaNDM-1, is a worrying phenomenon which highlights the importance of developing strategies to detect, prevent, and control the spread of these microorganisms. [ABSTRACT FROM AUTHOR]

In recent decades, Aeromonas hydrophila has emerged as a foodborne bacterial pathogen of public health concern, especially as it exhibits resistance to the major chemical sanitizers commonly used in the food industry. Meanwhile, this pathogen may be spread from diseased fish flesh through the contamination of equipment contact surfaces during food processing, thus posing a food safety risk. Thise determined the susceptibility profiles of retail fish-borne A. hydrophila isolates to 24 common antibiotics and five major sanitizers used in the food industry. The polymerase chain reaction technique was used to confirm all A. hydrophila isolates to the species level, and the agar diffusion method was applied to determine the antimicrobial susceptibility profiles. All isolates were confirmed to be A. hydrophila species. This bacterium was observed to have resistance to multiple antibiotics, with the highest resistance index being for those of the beta-lactam class. Additionally, the isolates showed high resistance to four of the five chemical sanitizers tested, with the highest resistance rate being toward sodium hypochlorite. The results suggested that A. hydrophila isolates with multiple resistance to the antimicrobials and main sanitizers used in the food industry can be found in retail fish sold in the Cuiabá region of Mato Grosso, Brazil. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Klebsiella pneumoniae (CRKP) are highly disseminated worldwide, and isolates co-resistant to other antimicrobial agents pose a threat to effective antimicrobial therapy. Therefore, evaluation of novel antimicrobial drugs is needed to identify potential treatments with better outcomes. We evaluated the in vitro activity of novel antimicrobial drugs/combinations against 97 KPC-producing Klebsiella pneumoniae isolates recovered from different hospitals in Brazil during 2021–2022. Clonality, resistance and virulence genes were detected by whole-genome sequencing. The majority of the isolates (54.6%) were classified as extensively drug resistant or multidrug resistant (44.3%); one isolate showed a pandrug resistance phenotype. The most active antimicrobial agents were meropenem-vaborbactam, cefiderocol, and ceftazidime-avibactam, with sensitivities higher than 90%; resistance to ceftazidime-avibactam was associated with KPC-33 or KPC-44 variants. Colistin and polymyxin B were active against 58.6% of the isolates. The 97 isolates were distributed into 17 different sequence types, with a predominance of ST11 (37.4%). Although high in vitro susceptibility rates were detected for meropenem-vaborbactam and cefiderocol, only ceftazidime-avibactam is currently available in Brazil. Our findings showed limited susceptibility to antimicrobial drugs employed for infection treatment of carbapenem-resistant K. pneumoniae, underscoring the urgent need for stringent policies for antimicrobial stewardship to preserve the activity of such drugs. [ABSTRACT FROM AUTHOR]

Strains P17 and P113 were isolated from animals hospitalized in the same clinic, whereas strain P112 was isolated from another veterinary clinic. Although carbapenems are not routinely used in veterinary medicine, reports of infection or colonization by carbapenemase-producing I Enterobacterales i and non-fermenters are increasing in companion animals worldwide.[[1], [3]] In Latin America, KPC-2-producing I Escherichia coli i ST648 and I Klebsiella pneumoniae i ST11 have been recently reported in dogs with urinary tract infections in Brazil.[5],[6] In this study, we report the emergence of the human-associated NDM-1-producing I Enterobacter hormaechei i clone ST136 as a pathogen of pets. [Extracted from the article]

Aims: To characterize the genetic relatedness, phenotypic and genotypic antimicrobial resistance and plasmid content of 80 Salmonella Infantis strains isolated from food, humans and veterinary sources from 2013 to 2018 in Brazil. Methods and results: Pulsed‐field gel electrophoresis and single‐nucleotide polymorphism analysis showed major clusters containing 50% and 38.8% of the strains studied respectively. Multilocus sequence typing assigned all strains to ST32. Disk‐diffusion revealed that 90% of the strains presented resistant or intermediate resistant profiles and 38.8% displayed multidrug resistance. Resistance genes for aminoglycosides (aac(6′)‐Iaa; aadA12; aph(3″‐Ib; aph(6)‐Id), β‐lactams (blaTEM‐1; blaCTX‐M‐8; blaCMY‐2), trimethoprim (dfrA8), tetracycline (tet(A)), amphenicols (floR), sulfonamide (sul2), efflux pumps (mdsA; mdsB), chromosomal point mutations in gyrB, parC, acrB and pmrA were detected. Strains harboured IncI, IncF, IncX, IncQ, IncN and IncR plasmids. Conclusions: The presence of a prevalent S. Infantis subtype in Brazil and the high antimicrobial resistance rates reinforced the potential hazard of this serovar for the public health and food safety fields. Significance and Impact of the Study: This is the first study characterizing a large set of S. Infantis from Brazil by whole‐genome sequencing, which provided a better local and global comprehension about the distribution and characteristics of this serovar of importance in the food, human and veterinary fields. [ABSTRACT FROM AUTHOR]

Aim: The current study was conducted to determine the antimicrobial resistance profile and genetic relatedness of Aeromonas sp. isolated from healthcare and urban effluents, wastewater treatment plant (WWTP) and river water. Methods and Results: We detected the presence of genes conferring resistance to β‐lactam, quinolone and aminoglycoside. Multilocus sequence typing was carried out to differentiate the strains, and multilocus phylogenetic analysis was used to identify the species. A total of 28 cefotaxime‐resistant Aeromonas sp. strains were identified, harbouring uncommon Guiana‐extended‐spectrum (GES)‐type β‐lactamases (GES‐1, GES‐5, GES‐7 and GES‐16). Multidrug‐resistant Aeromonas sp. were found in hospital wastewater, WWTP and sanitary effluent, and A. caviae was identified as the most prevalent species (85·7%). Conclusion: The release of untreated healthcare effluents, presence of antimicrobials in the environment, in addition to multidrug‐resistant Aeromonas sp., are all potential factors for the spread of resistance. Significance and Impact of the Study: We identified a vast repertoire of antimicrobial resistance genes (ARG) in Aeromonas sp. from diverse aquatic ecosystems, including those that encode enzymes degrading broad‐spectrum antimicrobials widely used to treat healthcare‐associated infections. Hospital and sanitary effluents serve as potential sources of bacteria harbouring ARG and are a threat to public health. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to conduct a cost-utility analysis of the use of the antiviral nirmatrelvir/ritonavir, applied to a vaccinated Brazilian population against COVID-19, from the perspective of the Brazilian Public Health System (SUS)., Methods: A microsimulation model was created with individual-level data and daily cycles, with a 1-year time horizon, to compare the current scenario of standard care with a scenario in which nirmatrelvir/ritonavir is offered to the population. Adults of any age group that received ≥2 doses of the COVID-19 vaccine formed the investigated population. Direct medical costs of the outpatients and inpatients admitted to the ward or intensive care unit were included. The effectiveness of the model was measured in quality-adjusted life-years (QALYs)., Results: In all simulations, the use of nirmatrelvir/ritonavir resulted in incremental costs per patient of US dollar (USD)245.86 and incremental effectiveness of 0.009 QALY, over a year. The incremental cost-utility ratio was USD27 220.70/QALY. The relative risk of the vaccinated population was the factor that affected the outcome most, according to the univariate sensitivity analysis. The probabilistic sensitivity analysis resulted in 100% of the simulations being more costly and effective, but that only 4% of them were below the established cost-effectiveness threshold of USD24 000.00/QALY. In the scenario considering only the population over 60 years old and immunosuppressed (of any age), the incremental cost-utility ratio was USD7589.37/QALY., Conclusions: The use of nirmatrelvir/ritonavir in the treatment of COVID-19 in a vaccinated population was cost-effective only for immunosuppressed individuals and people over 60 years of age., Competing Interests: Author Disclosures Links to the individual disclosure forms provided by the authors are available here., (Copyright © 2023 International Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)

CTX‐M‐type extended‐spectrum β‐lactamase (ESBL)‐producing Escherichia coli clones have been increasingly reported worldwide. In this regard, although discussions of transmission routes of these bacteria are in evidence, molecular data are lacking to elucidate the epidemiological impacts of ESBL producers in wild animals. In this study, we have screened 90 wild animals living in a surrounding area of São Paulo, the largest metropolitan city in South America, to monitor the presence of multidrug‐resistant (MDR) Gram‐negative bacteria. Using a genomic approach, we have analysed eight ceftriaxone‐resistant E. coli. Resistome analyses revealed that all E. coli strains carried blaCTX‐M‐type genes, prevalent in human infections, besides other clinically relevant resistance genes to aminoglycosides, β‐lactams, phenicols, tetracyclines, sulphonamides, trimethoprim, fosfomycin and quinolones. Additionally, E. coli strains belonged to international sequence types (STs) ST38, ST58, ST212, ST744, ST1158 and ST1251, and carried several virulence‐associated genes. Our findings suggest spread and adaptation of international clones of CTX‐M‐producing E. coli beyond urban settings, including wildlife from shared environments. [ABSTRACT FROM AUTHOR]

The emergence and dissemination of high-risk clones of Klebsiella pneumoniae producing extended-spectrum β-lactamases (ESBLs) in animal infections is a critical issue. We report the detection and genomic features of a multidrug-resistant (MDR) ESBL (CTX-M-15)-producing K. pneumoniae infecting a domestic cat. Whole-genome sequencing analysis identified the international ST340 (clonal group CG258), and genes and mutations conferring resistance to β-lactams, aminoglycosides, macrolides, phenicols, fosfomycin, sulfonamides, tetracycline, trimethoprim, and fluoroquinolones. In addition, the presence of genes encoding resistance to disinfectant and heavy metals hazardous to humans was also confirmed. The MDR profile exhibited by the strain contributed to treatment failure and death of the companion animal. Therefore, active surveillance of critical priority lineages of K. pneumoniae should not only focus on human infections but also on veterinary infections. [ABSTRACT FROM AUTHOR]

The discovery and tracking of antimicrobial resistance genes are essential for understanding the evolution of bacterial resistance and restraining its dispersion. Mammaliicoccus sciuri (formerly Staphylococcus sciuri) is the most probable evolutionary repository of the mecA gene, that later disseminated to S. aureus. In this study, we describe the first double mecA / mecC homologue-positive non- aureus staphylococci and mammaliicocci (NASM) from the American continent, also representing the first report of mecC- positive NASM in Brazil. Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin swab and milk sample collected from an ewe's left udder half. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including β-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food. Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface. • Genomic study of Mammaliicoccus sciuri strains co-harboring mecA and mecC genes. • The presence of broad resistomes and virulence-associated genes was confirmed. • Phylogenomic analysis showed clonal relatedness with strains from Asia and Europe. • Clonal similarity with strains from domestic animals and food is demonstrated. • Human-animal-environment interface spread of M. sciuri mec-type genes is discussed. [ABSTRACT FROM AUTHOR]

Background: The spread of carbapenemase- and extended-spectrum β-lactamase (ESBL)-producing gram-negative bacilli (GNB) represent a global public health threat that limits therapeutic options for hospitalized patients. This study aimed to evaluate the in-vitro susceptibility of β-lactam-resistant GNB to ceftazidime-avibactam (C/A) and ceftolozane-tazobactam (C/T), and investigate the molecular determinants of resistance., Methods: Overall, 101 clinical isolates of Enterobacterales and Pseudomonas aeruginosa collected from a general hospital in Brazil were analyzed. Susceptibility to the antimicrobial agents was evaluated using an automated method, and the minimum inhibitory concentrations (MIC50/90) of C/A and C/T were determined using Etest®. The β-lactamase-encoding genes were investigated using polymerase chain reaction., Results: High susceptibility to C/A and C/T was observed among ESBL-producing Enterobacterales (100% and 97.3% for CLSI and 83.8% for BRCAST, respectively) and carbapenem-resistant P. aeruginosa (92.3% and 87.2%, respectively). Carbapenemase-producing Klebsiella pneumoniae exhibited high resistance to C/T (80%- CLSI or 100%- BRCAST) but high susceptibility to C/A (93.4%). All carbapenem-resistant K. pneumoniae isolates were susceptible to C/A, whereas only one isolate was susceptible to C/T. Both antimicrobials were inactive against metallo-β-lactamase-producing K. pneumoniae isolates. Resistance genes were concomitantly identified in 44 (44.9%) isolates, with bla CTX-M and bla SHV being the most common., Conclusions: C/A and C/T were active against microorganisms with β-lactam-resistant phenotypes, except when resistance was mediated by metallo-β-lactamases. Most C/A- and C/T-resistant isolates concomitantly carried two or more β-lactamase-encoding genes (62.5% and 77.4%, respectively).

Aims To investigate Pseudomonas aeruginosa isolates from a hospital wastewater treatment plant ( HWTP), focusing on enzyme-based mechanisms of β-lactams resistance and the genetic relatedness among isolates. Methods and Results Forty-one Ps. aeruginosa strains recovered from a HWTP were identified by amplification of 16S rRNA gene. β-lactamase production was screened by disc diffusion, CHROMagar extended-spectrum β-lactamase (ESBL) and β-lactamase strips. β-lactamase and ESBL producing isolates were investigated by PCR for the presence of ESBL, metallo- β-lactamase and Klebsiella pneumoniae carbapenemase encoding genes. Thirty-four isolates (83%) were resistant to at least one antibiotic belonging to three or more classes. Out of these 34 isolates, 28 (82%) were classified as multidrug-resistant (MDR) and 6 (18%) extensively drug-resistant (XDR). Genetic relatedness by Enterobacterial Repetitive Intergenic Consensus sequence-PCR and Multilocus sequence typing analysis showed 20 distinct profiles and 15 sequencing types respectively. Clonal Complex 244 (CC244) shows the pathogenic potential of this clone carrying MDR and XDR strains from clinical, environmental and hospital waste sources. Conclusions Our results suggest that treatment facilities for hospital wastewater can stimulate the increase of antimicrobial resistance bacteria and genes. Significance and Impact of the Study The great genetic diversity of Ps. aeruginosa recovered from HWTP constantly released into aquatic systems allow the spread of antimicrobial-resistant organisms and genes. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae is one of the most important pathogens related to hospital-acquired infections. The incidence of infections by hypervirulent K. pneumoniae (hvKp), especially community-acquired infections, has been increasing in recent decades. The occurrence of multidrug-resistant (MDR) hvKp has been increasingly reported worldwide decreasing the treatment options, which is a concern. Aquatic environments have been considered a reservoir of MDR pathogens, which contribute to the spread of MDR pathogens. Therefore, this study aimed to characterize MDR-hvKp strains obtained from public aquatic environments using whole genome sequencing in Brazil. Resistome analysis showed ARGs to β-lactams, quinolones, tetracyclines, sulfonamides , and fosfomycin as well as several metal resistance genes. Virulome analysis showed several virulence genes. Besides, genomic islands, CRISPR and prophage-related sequences were also detected. MLST analysis revealed the presence of two novel sequences types (STs) belonging to different clonal complexes (CCs) [ST4415 (CC515) and ST4416 (CC2654)], and one already described [ST661 (CC661)]. The presence of MDR-hvKp lineages in water sources belonging to STs and CCs associated with humans and animals shows the ability of these pathogens to spread to different aquatic environments. This study reports for the first time two novel STs of MDR-hvKp as well as the presence of a rare ST661 closely related to outbreaks in aquatic environments, and contributes to surveillance studies and MDR-hvKp monitoring worldwide. Image 1 • Environmental MDR-hvKp isolated from aquatic environments in South America. • Novel sequences types of MDR-hvKp (ST4415 and ST4416) and a rare ST661. • Several antimicrobial resistance and virulence determinants in MDR-hvKp. • Co-occurrence of heavy metal resistance genes in MDR-hvKp. • Presence of high genomic islands, CRISPR and phage-related sequences. [ABSTRACT FROM AUTHOR]

Control and prevention of methicillin-resistant Staphylococcus aureus (MRSA) infections should include early identification of patients at higher risk of MRSA acquisition and analysis of isolates by discriminatory bacterial DNA typing methods. One hundred and three MRSA isolates cultured between Sept. 1994 and Sept. 1995 from 62 patients in two teaching hospitals (hospital 1, in Rio de Janeiro; hospital 2, in Minas Gerais) were tested for antimicrobial resistance and genomic DNA was analysed by pulsed-field gel electrophoresis (PFGE). Ten profiles were identified: A, B, C, I and J in hospital 1 and A, B, D, E, F, G and H in hospital 2. PFGE patterns A and B were isolated at both hospitals. The majority (80%) of isolates had similar PFGE patterns (type A). Subtype A1 was isolated at both hospitals, but was more frequent in hospital 2 (54%), while subtype A2 predominated in hospital 1 (63%). MRSA isolates were resistant to the majority of antimicrobial agents tested. However, susceptibility to vancomycin alone was found in 32% of the isolates at hospital 1, whereas 48% of isolates from hospital 2 were susceptible to both vancomycin and mupirocin, and 34% demonstrated susceptibility to vancomycin, mupirocin and chloramphenicol. Thirty-nine percent of all isolates were mupirocin-resistant, with 90% of these belonging to PFGE pattern A. Four main risk factors were associated with MRSA infection or colonisation which may be useful in the early identification of patients at risk: >7 days hospitalisation (95%), very dependent patients (84%), invasive procedures (79%) and recent antimicrobial therapy (79%). The data demonstrate that PFGE pattern A is disseminated in both hospitals. However, at both hospitals subtypes of pattern A and the other PFGE types were associated with different antibiotic resistance patterns.