RESUMO
Acinetobacter baumannii poses a significant health threat because of its frequent implications in hospital outbreaks and multidrug resistance (MDR). Here, we studied four A. baumannii isolates recovered during a hospital outbreak of severe or fatal cases to elucidate their diversity and factors contributing to their increased virulence and antibiotic resistance. The isolates were identified using MALDI-ToF and characterized using comparative genomics, PCR, and antimicrobial susceptibility tests. They were classified as ST126 and exhibited fewer than five chromosomal single-nucleotide variants and the same extrachromosomal content, indicating that they are a single strain (A. baumannii AB01). A. baumannii AB01 showed an MDR phenotype that could be linked to the carriage of parC and gyrA mutations, efflux transporters, aminoglycoside resistance genes, a class C beta-lactamase, and three carbapenemases, some of which are encoded on a 72 kb plasmid. ST126 is infrequent and has not been reported in Latin America, and our genomic data indicate a plausible origin for A. baumannii AB01 within the Pan Pacific region.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Proteínas de Bactérias , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Plasmídeos , beta-Lactamases , beta-Lactamases/genética , Humanos , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/genética , Plasmídeos/genética , Proteínas de Bactérias/genética , Antibacterianos/farmacologia , Masculino , Feminino , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , Pessoa de Meia-IdadeRESUMO
AIMS: It is well established that intracellular cAMP contributes to the relaxation of vas deferens smooth muscle. In many tissues, intracellular cAMP is actively transported to the extracellular space, where it exerts regulatory functions, via its metabolite adenosine. These actions take place through the cAMP conversion to adenosine by ectoenzymes, a process called "extracellular cAMP-adenosine pathway". Herein, we investigated whether, in addition to ATP, extracellular cAMP might be an alternative source of adenosine, influencing the contraction of vas deferens smooth muscle. MAIN METHODS: The effects of cAMP, 8-Br-cAMP and adenosine were analyzed in the isometric contractions of rat vas deferens. cAMP efflux was analyzed by measuring extracellular cAMP levels after exposure of vas deferens segments to isoproterenol and forskolin in the presence or absence of MK-571, an inhibitor of MRP/ABCC transporters. KEY FINDINGS: While 8-Br-cAMP, a cell-permeable cAMP analog, induced relaxation of KCl-precontracted vas deferens, the non-permeant cAMP increased the KCl-induced contractile response, which was mimicked by adenosine, but prevented by inhibitors of ecto-5'-nucleotidase or A1 receptors. Our results also showed that isoproterenol and forskolin increases cAMP efflux via an MRP/ABCC transporter-dependent mechanism, since it is inhibited by MK-571. SIGNIFICANCE: Our data show that activation of ß-adrenoceptors and adenylyl cyclase increases cAMP efflux from vas deferens tissue, which modulates the vas deferens contractile response via activation of adenosine A1 receptors. Assuming that inhibition of vas deferens contractility has been proposed as a strategy for male contraception, the extracellular cAMP-adenosine pathway emerges as a potential pharmacological target that should be considered in studies of male fertility.
Assuntos
5'-Nucleotidase , AMP Cíclico , Contração Muscular , Ratos Wistar , Receptor A1 de Adenosina , Ducto Deferente , Masculino , Animais , Ducto Deferente/efeitos dos fármacos , Ducto Deferente/metabolismo , AMP Cíclico/metabolismo , 5'-Nucleotidase/metabolismo , Receptor A1 de Adenosina/metabolismo , Receptor A1 de Adenosina/efeitos dos fármacos , Ratos , Contração Muscular/efeitos dos fármacos , Adenosina/farmacologia , Adenosina/análogos & derivados , Adenosina/metabolismo , Isoproterenol/farmacologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/metabolismo , Colforsina/farmacologiaRESUMO
Antibiotics and herbicides are contaminants of emerging concern in aquatic environments. Lake Villarrica is a relevant freshwater body in Chile and was recently designated a 'saturated nutrient zone'. Here, we investigated the occurrence of multiple antibiotic resistance (MAR) and herbicide catabolic profiles among bacteria present in the surface sediments of Lake Villarrica. The occurrence of antibiotic-resistant genes (ARGs; blaTEM, catA and tetM) and herbicide-catabolic genes (HCGs; phnJ and atzA) was investigated by qPCR. Subsequently, the presence of culturable bacteria with multiple resistance to amoxicillin (AMX), chloramphenicol (CHL) and oxytetracycline (OXT) was studied. Forty-six culturable MAR (AMX + CHL + OXT) strains were isolated and characterized with respect to their resistance to 11 antibiotics by using a disc diffusion assay and testing their ability to use herbicides as a nutrient source. qPCR analyses revealed that ARGs and HCGs were present in all sediment samples (101 to 103 gene copies g-1), with significant (P ≤ 0.05) higher values in sites near Villarrica city and cattle pastures. The plate method was used to recover MAR isolates from sediment (103-106 CFU g-1), and most of the 46 isolates also showed resistance to oxacillin (100%), cefotaxime (83%), erythromycin (96%) and vancomycin (93%). Additionally, 54 and 57% of the MAR isolates were able to grow on agar supplemented (50 mg L-1) with atrazine and glyphosate as nutrient sources, respectively. Most of the MAR isolates were taxonomically close to Pseudomonas (76.1%) and Pantoea (17.4%), particularly those isolated from urbanized sites (Pucón city). This study shows the presence of MAR bacteria with herbicide catabolic activity in sediments, which is valuable for conservation strategies and risk assessments of Lake Villarrica. However, major integrative studies on sediments as reservoirs or on the fate of MAR strains and traces of antibiotics and herbicides as a result of anthropic pressure are still needed.
Assuntos
Antibacterianos , Bactérias , Sedimentos Geológicos , Herbicidas , Lagos , Poluentes Químicos da Água , Herbicidas/farmacologia , Lagos/microbiologia , Sedimentos Geológicos/microbiologia , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Antibacterianos/farmacologia , Chile , Monitoramento Ambiental , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
Candida species are amongst the commensals of the mucosal surfaces of the human body which include the oral cavity, vagina, and intestinal mucosa. Fungal infections are on the rise worldwide. The overall burden of infections due to fungi is difficult to estimate because the majority of them remain undiagnosed. The present study aims to determine the burden of antifungal resistance in low socioeconomic country, Pakistan and the frequency of ERG11 and MDR1 genes involved. A total of 636 Candida isolates were obtained from various tertiary care institutions in Lahore in the form of culture on various culture plates. Sabouraud agar culture plates were used to culture the Candida spp. Antifungal resistance was determined against Fluconazole, Itraconazole, Ketoconazole, and Nystatin via disk diffusion technique. Most resistance was observed against Fluconazole followed by Itraconazole, Ketoconazole, and Nystatin. The Candida isolates recovering from CVP tip and tissue have a high resistance profile. Candida species resistant to at least two antifungals were chosen for further ERG11 and MDR1 detection through real-time PCR. Among 255 Candida isolates, 240 contained ERG11 gene while MDR1 gene is present in 149 Candida isolates. The isolates carrying both genes were tested by the broth microdilution technique for the susceptibility against cycloheximide, all of them were able to grow in cycloheximide. The genetic determinants of antifungal resistance such as ERG11 and MDR1 are as important in the multidrug resistance against a variety of compounds and antifungal drugs.
Assuntos
Antifúngicos , Candida , Cicloeximida , Testes de Sensibilidade Microbiana , Antifúngicos/farmacologia , Humanos , Candida/efeitos dos fármacos , Candida/genética , Candida/classificação , Candida/isolamento & purificação , Cicloeximida/farmacologia , Paquistão , Candidíase/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Farmacorresistência Fúngica Múltipla/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismoRESUMO
OBJECTIVE: Despite the increasing reports of blaNDM in Enterobacterales in Brazil, comprehensive whole genome sequencing (WGS) data remain scarce. To address this knowledge gap, our study focuses on the characterization of the genome of an New Delhi Metallo-ß-lactamase (NDM)-1-producing Klebsiella quasipneumoniae subsp. quasipneumoniae (KQPN) clinical strain isolated in Brazil. METHODS: The antimicrobial susceptibility profile of the A-73.113 strain was performed by agar dilution or broth microdilution following the Brazilian Antimicrobial Susceptibility Testing Committee/European Committee on Antimicrobial Susceptibility Testing recommendations. WGS was performed using the Illumina® NextSeq platform and the generated reads were assembled using the SPAdes software. The sequences obtained were submitted to the bioinformatics pipelines to determine the sequence type, resistome, plasmidome, and virulome. RESULTS: The A-73.113 strain was identified as KQPN and was susceptible to polymyxins (MICs, ≤0.25 µg/mL), tigecycline (MIC, 0.5 µg/mL), ciprofloxacin (MIC, 0.5 µg/mL), and levofloxacin (MIC, 1 µg/mL). WGS analysis revealed the presence of genes conferring resistance to ß-lactams (blaNDM-1, blaCTX-M-15, blaOXA-9, blaOKP-A-5, blaTEM-1), aminoglycosides [aph(3')-VI, aadA1, aac(6')-Ib], and fluoroquinolones (oqxAB, qnrS1, aac(6')-Ib-cr]. Additionally, the presence of the plasmid replicons Col(pHAD28), IncFIA(HI1), IncFIB(K) (pCAV1099-114), IncFIB(pQil), and IncFII(K), as well as virulence-encoding genes fimABCDEFGHIK (type 1 fimbria), pilW (type IV pili), iutA (aerobactin), entABCDEFS/fepABCDG/fes (Ent siderophores), iroE (salmochelin), and allABCDRS (allantoin utilization) was verified. Furthermore, we found that the A-73.113 strain belongs to ST1040. CONCLUSIONS: Here we report the genomic characteristics of an NDM-1-producing KQPN ST1040 strain isolated from blood cultures in Brazil. These data will enhance our comprehension of how this species contributes to the acquisition and dissemination of blaNDM-1 in Brazilian nosocomial settings.
Assuntos
Antibacterianos , Genoma Bacteriano , Infecções por Klebsiella , Klebsiella , Testes de Sensibilidade Microbiana , Plasmídeos , Sequenciamento Completo do Genoma , beta-Lactamases , beta-Lactamases/genética , Humanos , Klebsiella/genética , Klebsiella/efeitos dos fármacos , Klebsiella/isolamento & purificação , Klebsiella/enzimologia , Antibacterianos/farmacologia , Infecções por Klebsiella/microbiologia , Plasmídeos/genética , Brasil , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
The indiscriminate use of antimicrobials has led to the emergence of resistant bacteria, especially pathogenic strains of Escherichia coli, which are associated with diseases in animals and humans. The aim of the present study was to characterize E. coli isolates in calves with regards to the presence of virulence genes and investigate the resistance of the isolates to different antimicrobials. Between 2021 and 2023, 456 fecal samples were collected from calves in the Pantanal and Cerrado biomes of the state of Mato Grosso do Sul, Brazil. All samples were subjected to microbiological analysis and disc diffusion antibiogram testing. The polymerase chain reaction method was used to detect virulence genes. Bacterial growth was found in 451 of the 456 samples and biochemically identified as Escherichia coli. All 451 isolates (100 %) exhibited some phenotypic resistance to antimicrobials and 67.62 % exhibited multidrug resistance. The frequency of multidrug-resistant isolates in the Cerrado biome was significantly higher than that in the Pantanal biome (p = 0.0001). In the Cerrado, the most common pathotype was Shiga toxin-producing Escherichia coli (STEC) (28 %), followed by toxigenic Escherichia coli (ETEC) (11 %), enterohemorrhagic Escherichia coli (EHEC) (8 %) and enteropathogenic Escherichia coli (EPEC) (2 %). In most cases, the concomitant occurrence of pathotypes was more common, the most frequent of which were ETEC + STEC (33 %), ETEC + EHEC (15 %) and ETEC + EPEC (3 %). The STEC pathotype (30 %) was also found more frequently in the Pantanal, followed by EHEC (12 %), ETEC (9 %) and EPEC (6 %). The STEC pathotype had a significantly higher frequency of multidrug resistance (p = 0.0486) compared to the other pathotypes identified. The frequency of resistance was lower in strains from the Pantanal biome compared to those from the Cerrado biome. Although some factors are discussed in this paper, it is necessary to clarify the reasons for this difference and the possible impacts of these findings on both animal and human health in the region.
Assuntos
Antibacterianos , Doenças dos Bovinos , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli , Escherichia coli , Fezes , Testes de Sensibilidade Microbiana , Fatores de Virulência , Animais , Bovinos , Brasil , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/epidemiologia , Fezes/microbiologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/epidemiologia , Fatores de Virulência/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Escherichia coli Êntero-Hemorrágica/genética , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Escherichia coli Êntero-Hemorrágica/efeitos dos fármacos , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Escherichia coli Enterotoxigênica/genética , Escherichia coli Enterotoxigênica/isolamento & purificação , Proteínas de Escherichia coli/genéticaRESUMO
The antimicrobial activity of Vismia macrophylla extract is reported in the literature; however, little is known about the presence of phenolic compounds and their antimicrobial activity in this species. This study aimed to isolate phenolic compounds with antimicrobial action from the leaves of V. macrophylla. The ethanolic extract (VmL-Et) was submitted to sephadex column separation, and some fractions were submitted to derivatization with BSTFA and analysed by GC-MS. This study indicated the presence of the catechin, osajaxanthone, quercetin, quercitrin, and glucodistylin. Of these, osajaxanthone, quercetin, quercitrin, and glucodistylin were isolated and identified by spectroscopic techniques. VmL-Et, quercetin, quercitrin, glucodistylin, and maslinic acid, were tested against the Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. The results showed broad spectrum action of the extract Vm-Et, glucodistylin and quercitrin. The species V. macrophylla occurring in the Brazilian biome showed potential for obtaining phenolic compounds that can help combat microbial resistance.
RESUMO
Staphylococcus aureus is one of the primary pathogenic agents found in cheeses produced with raw milk. Some strains of S. aureus are enterotoxigenic, possessing the ability to produce toxins responsible for staphylococcal food poisoning when present in contaminated foods. This study aimed to genotypically characterize, assess the antimicrobial resistance profile, and examine the enterotoxigenic potential of strains of S. aureus isolated from artisanal colonial cheese. Additionally, a bacterial diversity assessment in the cheeses was conducted by sequencing the 16S rRNA gene. The metataxomic profile revealed the presence of 68 distinct species in the cheese samples. Fifty-seven isolates of S. aureus were identified, with highlighted resistance to penicillin in 33% of the isolates, followed by clindamycin (28%), erythromycin (26%), and tetracycline (23%). The evaluated strains also exhibited inducible resistance to clindamycin, with nine isolates considered multidrug-resistant (MDR). The agr type I was the most prevalent (62%) among the isolates, followed by agr type II (24%). Additionally, ten spa types were identified. Although no enterotoxins and their associated genes were detected in the samples and isolates, respectively, the Panton-Valentine leukocidin gene (lukS-lukF) was found in 39% of the isolates. The presence of MDR pathogens in the artisanal raw milk cheese production chain underscores the need for quality management to prevent the contamination and dissemination of S. aureus strains.
Assuntos
Antibacterianos , Queijo , Leite , Staphylococcus aureus , Queijo/microbiologia , Brasil , Leite/microbiologia , Animais , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Virulência , Microbiologia de Alimentos , Humanos , Farmacorresistência Bacteriana , Contaminação de Alimentos/análise , Enterotoxinas/genéticaRESUMO
The objective of the study was to detect multidrug-resistant Staphylococcus sp. and Enterococcus sp. isolates in municipal and hospital wastewater and to determine their elimination or persistence after wastewater treatment. Between August 2021 and September 2022, raw and treated wastewater samples were collected at two hospital and two community wastewater treatment plants (WWTPs). In each season of the year, two treated and two raw wastewater samples were collected in duplicate at each of the WWTPs studied. Screening and presumptive identification of staphylococci and enterococci was performed using chromoagars, and identification was performed with the Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-TOF MS®). Antimicrobial susceptibility was performed using VITEK 2® automated system. There were 56 wastewater samples obtained during the study period. A total of 182 Staphylococcus sp. and 248 Enterococcus sp. were identified. The highest frequency of Staphylococcus sp. isolation was in spring and summer (n = 129, 70.8%), and for Enterococcus sp. it was in autumn and winter (n = 143, 57.7%). Sixteen isolates of Staphylococcus sp. and sixty-three of Enterococcus sp. persisted during WWTP treatments. Thirteen species of staphylococci and seven species of enterococci were identified. Thirty-one isolates of Staphylococcus sp. and ninety-four of Enterococcus sp. were multidrug-resistant. Resistance to vancomycin (1.1%), linezolid (2.7%), and daptomycin (8.2%/10.9%%), and a lower susceptibility to tigecycline (2.7%), was observed. This study evidences the presence of Staphylococcus sp. and Enterococcus sp. resistant to antibiotics of last choice of clinical treatment, in community and hospital wastewater and their ability to survive WWTP treatment systems.
RESUMO
Microbial resistance to antibiotics poses a significant threat to both human and animal health, necessitating international efforts to mitigate this issue. This study aimed to assess the resistance profiles of Salmonella sp. isolates and identify the presence of intl1, sul1, and blaTEM resistance genes within antigenically characterized isolates, including Agona, Livingstone, Cerro, Schwarzengrund, Salmonella enterica subsp. enterica serotype O:4.5, Anatum, Enteritidis, Johannesburg, Corvallis, and Senftenberg. These isolates underwent susceptibility testing against 14 antibiotics. The highest resistance percentages were noted for sulfamethoxazole (91%), sulfonamides (51%), and ceftiofur (28.9%), while no resistance was observed for ciprofloxacin. Salmonella Johannesburg and Salmonella Corvallis showed resistance to one antibiotic, whereas other serovars were resistant to at least two. Salmonella Schwarzengrund exhibited resistance to 13 antibiotics. The intl1 gene was detected in six out of the ten serovars, and the sul1 gene in three, always co-occurring with intl1. The blaTEM gene was not identified. Our findings highlight the risk posed by the detected multiple resistances and genes to animal, human, and environmental health. The multidrug resistance, especially to third-generation cephalosporins and fluoroquinolones, highlights the need for stringent monitoring of Salmonella in laying hens. The potential of the environment, humans, eggs, and their products to act as vectors for antibiotic resistance represents a significant concern for One Health.