RESUMO
Recent research has identified multiple immune systems that bacteria use to protect themselves from viral infections. However, little is known about the mechanisms by which these systems horizontally spread, especially among bacterial pathogens. Here, we investigate antiviral defenses in staphylococci, opportunistic pathogens that constitute leading causes of antibiotic-resistant infections. We show that these organisms harbor a variety of anti-phage defenses encoded within or near SCC (staphylococcal cassette chromosome) mec cassettes, mobile genomic islands that confer methicillin resistance. Importantly, we demonstrate that SCCmec-encoded recombinases mobilize not only SCCmec, but also tandem SCC-like cassettes enriched in genes coding for diverse defense systems. Further, we show that phage infection stimulates cassette mobilization (i.e. excision and circularization). Thus, our findings indicate that SCC/SCCmec cassettes not only spread antibiotic resistance but can also play a role in mobilizing anti-phage defenses.
Assuntos
Ilhas Genômicas , Ilhas Genômicas/genética , Staphylococcus/genética , Recombinases/metabolismo , Recombinases/genética , Resistência a Meticilina/genética , Fagos de Staphylococcus/genética , Transferência Genética Horizontal , Staphylococcus aureus Resistente à Meticilina/genética , Bacteriófagos/genética , Bacteriófagos/fisiologia , Cromossomos Bacterianos/genéticaRESUMO
High-level resistance to methicillin requires a distinct form of cell division.
Assuntos
Antibacterianos , Divisão Celular , Divisão Celular/efeitos dos fármacos , Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Resistência a MeticilinaRESUMO
Methicillin-resistant Staphylococci (MRS) cause infections at various sites and exhibit multidrug resistance. Despite their importance in veterinary medicine, only little is known about Staphylococcus spp. colonizing and infecting cats. Therefore, in this study, we aimed to isolate and identify Staphylococcus spp. colonizing hospitalized and non-hospitalized domestic cats and analyze their antimicrobial resistance profiles, genetic diversity, and risk factors associated with MRS colonization. A total of 218 oral and axillary swabs were obtained from 109 cats, including 77 non-hospitalized and 32 hospitalized cats. After plating on selective media, the isolates were identified via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and rpoB and 16S rRNA gene sequencing. Subsequently, antimicrobial sensitivity of the strains was assessed, and they were screened for mecA gene. Methicillin-resistant S. haemolyticus (MRSH) isolates were subjected to multilocus sequence typing, whereas methicillin-resistant S. pseudintermedius (MRSP) and S. felis isolates were subjected to whole genome sequencing. S. felis was most commonly isolated from non-hospitalized cats (28.1%), whereas S. pseudintermedius and MRS were commonly isolated from hospitalized cats (25%). MRSH isolates from hospitalized animals were classified as ST3. The identified MRSP strains belonged to two well-known sequence types, ST551 and ST71. Moreover, antimicrobial use (p = 0.0001), hospitalization (p = 0.0141), and comorbidities (p = 0.002) were associated with increased MRS prevalence in cats.
Assuntos
Doenças do Gato , Variação Genética , Infecções Estafilocócicas , Animais , Gatos/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/epidemiologia , Brasil , Doenças do Gato/microbiologia , Antibacterianos/farmacologia , Staphylococcus/genética , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Feminino , Testes de Sensibilidade Microbiana , Masculino , RNA Ribossômico 16S/genética , Resistência a Meticilina/genética , Hospitalização , Proteínas de Bactérias/genética , Tipagem de Sequências MultilocusRESUMO
Staphylococcus saprophyticus, a common uropathogen, is usually susceptible to urine-concentrating antimicrobials, so routine AST is not recommended by CLSI. Our study evaluated the antimicrobial resistance profiles of 277 S. saprophyticus isolates from North America and a globally diverse cohort. Notably, 24% (67/277) of our isolates come from non-urinary sources. AST was performed against 12 antimicrobials using standard disk diffusion, PCR for mecA and mecC, PBP2a production assays, and cefinase. 5% (13/277) of isolates were mecA positive and cefinase positive, 63% (176/277) were mecA negative but cefinase positive, 4% (11/277) were mecA positive but cefinase negative, and 28% (77/277) were mecA and cefinase negative. All (277/277) isolates were susceptible to delafloxacin, ciprofloxacin, rifampin, linezolid, and nitrofurantoin and 95% (262/277) were susceptible to trimethoprim-sulfamethoxazole. Our results showed that regardless of using CLSI or EUCAST breakpoints oxacillin had low categorical agreement for mecA presence, making it unsuitable for surrogate testing, while cefoxitin disk diffusion had high very major error rate. If possible, PBP2a or mecA testing is recommended for guiding therapy for non-urinary infections. Our work supports CLSI guidelines on routine susceptibility to urinary tract antibiotics.
Assuntos
Antibacterianos , Resistência a Meticilina , Infecções Estafilocócicas , Staphylococcus saprophyticus , Humanos , Staphylococcus saprophyticus/efeitos dos fármacos , Staphylococcus saprophyticus/genética , Staphylococcus saprophyticus/isolamento & purificação , Antibacterianos/farmacologia , Infecções Estafilocócicas/microbiologia , Resistência a Meticilina/genética , Testes de Sensibilidade Microbiana , Proteínas de Bactérias/genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Proteínas de Ligação às Penicilinas/genética , América do NorteRESUMO
BACKGROUND Septic arthritis of the shoulder is a rare and challenging condition to treat. Typically, arthroscopic debridement is the common approach. Specifically, septic arthritis of the shoulder caused by methicillin-resistant bacteria is extremely difficult to cure due to persistent infection and limited antibiotic options. However, recent studies have demonstrated that continuous local antibiotic perfusion (CLAP) can provide favorable results for bone and soft tissue infections. By administering the antibiotics required to suppress the biofilm, CLAP can effectively treat the infection while sparing the tissue. CASE REPORT A 46-year-old woman undergoing long-term hemodialysis treatment for congenital anomalies of the kidney and urinary tract experienced severe pain in the left shoulder joint during glucocorticoid treatment for amyloid arthritis of the right shoulder. Despite the absence of fever, significant swelling and fluid accumulation were observed in the left shoulder joint, leading to the performance of a puncture. A bacterial examination of the puncture fluid detected methicillin-resistant coagulase-negative Staphylococcus epidermidis (MRCNS). In this report, we present a case in which CLAP was administered for septic arthritis of the shoulder caused by methicillin-resistant bacteria. After irrigation debridement, the patient received intravenous antibiotics and CLAP. Following the initiation of treatment, the dosage of antibiotics was adjusted while performing therapeutic drug monitoring. An early improvement in the inflammatory response and sedation of the infection was observed, with no relapse after 2 years. CONCLUSIONS Septic arthritis can lead to serious functional impairment if left untreated. CLAP is a promising option for managing septic arthritis of the shoulder.
Assuntos
Antibacterianos , Artrite Infecciosa , Articulação do Ombro , Infecções Estafilocócicas , Humanos , Feminino , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/microbiologia , Artrite Infecciosa/terapia , Pessoa de Meia-Idade , Antibacterianos/uso terapêutico , Articulação do Ombro/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Desbridamento , Seguimentos , Staphylococcus epidermidis/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Resistência a MeticilinaRESUMO
BACKGROUND: Methicillin-resistant Staphylococcus haemolyticus (MRSH) is an important pathogenic agent of bovine mastitis. Among the prominent clone lineages in dairy cows are MRSH sequence types ST3 and ST42. Little information is available on the complete characterization of SCCmec elements in MRSH. OBJECTIVE: In this study, two clinical isolates of MRSH ST3 and ST42 from bovine mastitis milk were selected, and their nontypable SCCmec structures were compared. METHODS: Two MRSH strains, MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1, were identified from bovine mastitis milk in Thailand in 2022. Minimum inhibitory concentration was used to screen for antimicrobial resistance susceptibility. Oxford Nanopore Technologies and Illumina sequencing were performed in combination to complete the genome. Their gene organization and structure of SCCmec types were analysed and compared with the whole sequences of other strains in the same sequence types. RESULTS: Both MRSH-ST3 strain M62.3 and MRSH-ST42 strain M81.1 possessed the class C1 mec complex but lacked the ccr gene complex. Notably, MRSH-ST42 strain M81.1 contained a novel variant of C1 mec complex, which consisted of IS431-mecA-ISSha1-paaZ-upgQ-IS431, with IS431 organized in the same orientation. Apart from class C1 mec and the heavy metal-resistant cluster, the gene composition and order of the SCCmec element varied. In ST3, variations in the SCCmec type, gene content and organization were observed. CONCLUSIONS: The distinct evolution of the MRSH lineage was indicated by the various SCCmec elements. The insertion of ISSha1 resulted in a unique variant of class C1 mec complex that demonstrated the important role of the insertion sequence in SCCmec diversification.
Assuntos
Antibacterianos , Mastite Bovina , Testes de Sensibilidade Microbiana , Leite , Infecções Estafilocócicas , Staphylococcus haemolyticus , Animais , Mastite Bovina/microbiologia , Bovinos , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/efeitos dos fármacos , Staphylococcus haemolyticus/isolamento & purificação , Feminino , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Antibacterianos/farmacologia , Tailândia , Cromossomos Bacterianos/genética , Resistência a Meticilina/genética , Genoma Bacteriano , Sequenciamento Completo do GenomaRESUMO
Staphylococcus pseudintermedius is an opportunistic pathogen in dogs, and infection in humans is increasingly found, often linked to contact with dogs. We conducted a retrospective genotyping and antimicrobial susceptibility testing study of 406 S. pseudintermedius isolates cultured from animals (dogs, cats and an otter) and humans across Scotland, from 2007 to 2020. Seventy-five sequence types (STs) were identified, among the 130 isolates genotyped, with 59 seen only once. We observed the emergence of two methicillin resistant Staphylococcus pseudintermedius (MRSP) clones in Scotland: ST726, a novel locally-evolving clone, and ST551, first reported in 2015 in Poland, possibly linked to animal importation to Scotland from Central Europe. While ST71 was the most frequent S. pseudintermedius strain detected, other lineages that have been replacing ST71 in other countries, in addition to ST551, were detected. Multidrug resistance (MDR) was detected in 96.4% of MRSP and 8.4% of MSSP. A single MRSP isolate was resistant to mupirocin. Continuous surveillance for the emergence and dissemination of novel MDR MRSP in animals and humans and changes in antimicrobial susceptibility in S. pseudintermedius is warranted to minimise the threat to animal and human health.
Assuntos
Resistência a Meticilina , Animais de Estimação , Infecções Estafilocócicas , Staphylococcus , Sequenciamento Completo do Genoma , Animais , Escócia , Staphylococcus/genética , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificação , Cães/microbiologia , Gatos/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/epidemiologia , Humanos , Resistência a Meticilina/genética , Animais de Estimação/microbiologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Doenças do Cão/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Doenças do Gato/microbiologiaRESUMO
The accurate and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) holds significant clinical importance. This work presents a new method for detecting methicillin-resistant Staphylococcus aureus (S. aureus) in clinical samples. The method uses an aptamer-based colorimetric assay that combines a recognizing probe to identify the target and split DNAzyme to amplify the signal, resulting in a highly sensitive and direct analysis of methicillin-resistance. The identification of the PBP2a protein on the membrane of S. aureus in clinical samples leads to the allosterism of the recognizing probe, and thus provides a template for the proximity ligation of split DNAzyme. The proximity ligation of split DNAzyme forms an intact DNAzyme to identify the loop section in the L probe and generates a nicking site to release the loop sequence ("3" and "4" fragments). The "3" and "4" fragments forms an intact sequence to induce the catalytic hairpin assembly, exposing the G-rich section. The released the G-rich sequence of LR probe induces the formation of G-quadruplex-hemin DNAzyme as a colorimetric signal readout. The absorption intensity demonstrated a strong linear association with the logarithm of the S. aureus concentration across a wide range of 5 orders of magnitude dynamic range under the optimized experimental parameters. The limit of detection was calculated to be 23 CFU/ml and the method showed high selectivity for MRSA.
Assuntos
Aptâmeros de Nucleotídeos , Colorimetria , DNA Catalítico , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , DNA Catalítico/metabolismo , Colorimetria/métodos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/diagnóstico , Humanos , Técnicas Biossensoriais/métodos , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Sensibilidade e Especificidade , Resistência a Meticilina , Proteínas de Ligação às Penicilinas/metabolismo , Proteínas de Ligação às Penicilinas/genéticaRESUMO
The emergence of antimicrobial resistance, exemplified by methicillin-resistant Staphylococcus aureus (MRSA), poses a grave threat to public health globally. Over time, MRSA has evolved resistance to multiple antibiotics, challenging conventional treatment strategies. The relentless adaptability of MRSA underscores the urgent need for innovative and targeted antimicrobial approaches to combat this resilient pathogen. Ancient knowledge and practices, along with scientific evidence, have established that metallic copper, and its organic coordination complexes can act as potential antibacterial substances. In search of a smart and effective antimicrobial against MRSA, we designed, synthesized, and characterized a bidentate copper(II) ligand complex (SG-Cu) utilizing a comprehensive array of analytical techniques, including ESI-MS, elemental analysis, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and others. Antibacterial efficacy and mechanism of action of the complex were assessed through bacterial growth analyses, bacterial membrane perturbation assays, ROS elicitation assays, and field emission scanning electron microscopy. SG-Cu was found to maintain robust biocompatibility against the mammalian cell lines HEK-293, WI-38, and NIH/3T3. Remarkably, SG-Cu demonstrated significant biofilm disruptive tendency evidenced by the retardation of sliding motility, reduction in slime production, reduction in biofilm viability, and enhanced biofilm eradication, both in vitro and in urinary catheters. In vivo studies on murine excisional wounds, with SG-Cu impregnated in a palmitic acid conjugated NAVSIQ hexapeptide (PA-NV) hydrogel, revealed the sustained release of SG-Cu from the gel matrix, facilitating accelerated wound healing and effective wound disinfection. This multifaceted investigation highlights the potential of SG-Cu as a versatile option for combating MRSA infections and promoting wound healing, solidifying its claim to be developed into a viable therapeutic.
Assuntos
Antibacterianos , Cobre , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina , Compostos de Cobre Orgânico , Quinolinas , Infecções Estafilocócicas , Cicatrização , Infecção dos Ferimentos , Quinolinas/síntese química , Quinolinas/farmacologia , Quinolinas/uso terapêutico , Cobre/química , Cobre/farmacologia , Cobre/uso terapêutico , Ligantes , Hidrogéis/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Cápsulas , Cicatrização/efeitos dos fármacos , Humanos , Animais , Camundongos , Células HEK293 , Células NIH 3T3 , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/metabolismo , Compostos de Cobre Orgânico/síntese química , Compostos de Cobre Orgânico/farmacologia , Compostos de Cobre Orgânico/uso terapêuticoRESUMO
BACKGROUND: Recently, linezolid-resistant staphylococci have become an emerging problem worldwide. Understanding the mechanisms of resistance, molecular epidemiology and transmission of linezolid-resistant CoNS in hospitals is very important. METHODS: The antimicrobial susceptibilities of all isolates were determined by the microdilution method. The resistance mechanisms and molecular characteristics of the strains were determined using whole-genome sequencing and PCR. RESULTS: All the strains were resistant to oxacillin and carried the mecA gene; 13 patients (36.1%) had prior linezolid exposure. Most S. epidermidis and S. hominis isolates were ST22 and ST1, respectively. MLST typing and evolutionary analysis indicated most linezolid-resistant CoNS strains were genetically related. In this study, we revealed that distinct CoNS strains have different mechanisms of linezolid resistance. Among ST22-type S. epidermidis, acquisition of the T2504A and C2534T mutations in the V domain of the 23 S rRNA gene, as well as mutations in the ribosomal proteins L3 (L101V, G152D, and D159Y) and L4 (N158S), were linked to the development of linezolid resistance. In S. cohnii isolates, cfr, S158Y and D159Y mutations in the ribosomal protein L3 were detected. Additionally, emergence of the G2576T mutation and the cfr gene were major causes of linezolid resistance in S. hominis isolates. The cfr gene, G2576T and C2104T mutations, M156T change in L3 protein, and I188S change in L4 protein were found in S. capitis isolates. CONCLUSION: The emergence of linezolid-resistant CoNS in the environment is concerning because it involves clonal dissemination and frequently coexists with various drug resistance mechanisms.
Assuntos
Antibacterianos , Linezolida , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas , Centros de Atenção Terciária , Linezolida/farmacologia , Humanos , China/epidemiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/epidemiologia , Antibacterianos/farmacologia , Feminino , Masculino , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Idoso , Sequenciamento Completo do Genoma , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Staphylococcus/classificação , Staphylococcus/enzimologia , Coagulase/metabolismo , Coagulase/genética , RNA Ribossômico 23S/genética , Adulto , Resistência a Meticilina/genética , Mutação , Proteínas de Bactérias/genéticaRESUMO
BACKGROUND: Staphylococcus pseudintermedius is a common opportunistic pathogen of companion dogs and an occasional human pathogen. Treatment is hampered by antimicrobial resistance including methicillin resistance encoded by mecA within the mobile genetic element SCCmec. OBJECTIVES: SCCmec elements are diverse, especially in non-Staphyloccocus aureus staphylococci, and novel variants are likely to be present in S. pseudintermedius. The aim was to characterize the SCCmec elements found in four canine clinical isolates of S. pseudintermedius. MATERIAL AND METHODS: Isolates were whole-genome sequenced and SCCmec elements were assembled, annotated and compared to known SCCmec types. RESULTS AND DISCUSSION: Two novel SSCmec are present in these isolates. SCCmec7017-61515 is characterized by a novel combination of a Class A mec gene complex and a type 5 ccr previously only described in composite SCCmec elements. The other three isolates share a novel composite SCCmec with features of SCCmec types IV and VI. CONCLUSIONS: S. pseudintermedius is a reservoir of novel SSCmec elements that has implications for understanding antimicrobial resistant in veterinary and human medicine.
Assuntos
Cromossomos Bacterianos , Doenças do Cão , Resistência a Meticilina , Infecções Estafilocócicas , Staphylococcus , Sequenciamento Completo do Genoma , Resistência a Meticilina/genética , Staphylococcus/genética , Staphylococcus/efeitos dos fármacos , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Animais , Cães , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Doenças do Cão/microbiologia , Cromossomos Bacterianos/genética , Proteínas de Bactérias/genética , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Genoma Bacteriano , Variação Genética , Sequências Repetitivas Dispersas/genéticaRESUMO
BACKGROUND: Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an important veterinary pathogen. In general, only a few antimicrobials show in vitro activity against MRSP isolates. OBJECTIVES: The objective of this study was to determine the in vitro activity of selected antimicrobials, including last-choice drugs, against clinical MRSP isolates of canine origin. The activity of 10 selected agents was evaluated against 41 clinical MRSP isolates. METHODS: The disk diffusion method and minimal inhibitory concentration values were used for antimicrobial susceptibility testing (AST). The guidelines for staphylococci of canine or human origin were employed for the interpretation of the results. RESULTS: Among the examined MRSP isolates, resistance to enrofloxacin and clindamycin was the most prevalent (n = 40; 97.6%). Resistance to doxycycline and gentamicin was observed in 83.0% (n = 34) and 68.3% (n = 28) of the isolates, respectively. Single isolates were resistant to chloramphenicol (n = 5; 12.2%) and rifampicin (n = 3; 7.3%), whereas all showed susceptibility to amikacin, vancomycin, mupirocin and linezolid. Predominantly, the results of AST obtained by both methods were consistent. Some discrepancies were observed for gentamicin; however, clinical breakpoints for staphylococci of human origin were used. CONCLUSIONS: Amikacin and chloramphenicol constitute potential treatment options in infections caused by MRSP and may be included in extended susceptibility testing in our geographical region. The determination of clinical breakpoints for some antimicrobials not incorporated in the recommendations should be a high priority in the veterinary diagnostics.
Assuntos
Anti-Infecciosos , Doenças do Cão , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Staphylococcus , Animais , Cães , Humanos , Resistência a Meticilina , Infecções Estafilocócicas/veterinária , Amicacina , Polônia/epidemiologia , Anti-Infecciosos/farmacologia , Gentamicinas/farmacologia , Cloranfenicol , Doenças do Cão/tratamento farmacológico , Doenças do Cão/epidemiologiaRESUMO
The accurate and rapid detection of methicillin-resistance of Staphylococcus aureus (SA) holds significant clinical importance. However, the methicillin-resistance detection strategies commonly require complicated cell lysis and gene extraction. Herein, we devised a novel colorimetric approach for the sensitive and accurate identification of methicillin-resistance of SA by combining allosteric probe-based target recognition with self-primer elongation-based target recycling. The PBP2a aptamer in the allosteric probe successfully identified the target MRSA, leading to the initiation of self-primer elongation based-cascade signal amplification. The peroxidase-like hemin/G-quadruplex undergo an isothermal autonomous process that effectively catalyzes the oxidation of ABTS2- and produces a distinct blue color, enabling the visual identification of MRSA at low concentrations. The method offers a shorter duration for bacteria cultivation compared to traditional susceptibility testing methods, as well as simplified manual procedures for gene analysis. The overall amplification time for this test is 60 min, and it has a detection limit of 3 CFU/ml. In addition, the approach has exceptional selectivity and reproducibility, demonstrating commendable performance when tested with real samples. Due to its advantages, this colorimetric assay exhibits considerable potential for integration into a sensor kit, thereby offering a viable and convenient alternative for the prompt and on-site detection of MRSA in patients with skin and soft tissue infections.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus/genética , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/genética , Colorimetria , Meticilina , Reprodutibilidade dos Testes , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologiaRESUMO
Dual-species biofilms formed by Candida albicans and Staphylococcus aureus have high virulence and drug resistance. In this context, biosurfactants produced by Pseudomonas aeruginosa have been widely studied, of which a new derivative (RLmix_Arg) stands out for possible application in formulations. The objective of this study was to evaluate the antibiofilm activity of RLmix_Arg, both alone and incorporated in a gel prepared with Pluronic F-127, against dual-species biofilms of fluconazole-resistant C. albicans (FRCA) and methicillin-resistant S. aureus (MRSA) in impregnated catheters. Broth microdilution tests, MTT reduction assays of mature biofilms, impregnation of RLmix_Arg and its gel in peripheral venous catheters, durability tests and scanning electron microscopy (SEM) were performed. RLmix_Arg showed antimicrobial activity against Candida spp. and S. aureus, by reducing the cell viability of mixed biofilms of FRCA and MRSA, and preventing their formation in a peripheral venous catheter. The incorporation of this biosurfactant in the Pluronic F-127 gel considerably enhanced its antibiofilm activity. Thus, RLmix_Arg has potential application in gels for impregnation in peripheral venous catheters, helping to prevent development of dual-species biofilms of FRCA and MRSA.
Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Fluconazol/farmacologia , Candida albicans , Staphylococcus aureus , Resistência a Meticilina , Biofilmes , Poloxâmero/farmacologia , Testes de Sensibilidade Microbiana , Anti-Infecciosos/farmacologia , Catéteres , Antibacterianos/farmacologiaRESUMO
OBJECTIVES: Staphylococcus epidermidis is a member of the human skin microbiome. However, in recent decades, multidrug-resistant and hospital-adapted S. epidermidis clones are increasingly involved in severe human infections associated with medical devices and in immunocompromised patients. In 2016, we reported that a linezolid- and methicillin-resistant S. epidermidis ST2 clone, bearing the G2576T mutation, was endemic in an Italian hospital since 2004. This study aimed to retrospectively analyse 34 linezolid- and methicillin-resistant S. epidermidis (LR-MRSE) strains collected from 2018 to 2021 from the same hospital. METHODS: LR-MRSE were typed by Pulsed-Field Gel Electrophoresis and multilocus sequence typing and screened for transferable linezolid resistance genes. Representative LR-MRSE were subjected to whole-genome sequencing (WGS) and their resistomes, including the presence of ribosomal mechanisms of linezolid resistance and of rpoB gene mutations conferring rifampin resistance, were investigated. RESULTS: ST2 lineage was still prevalent (19/34; 55.9%), but, over time, ST5 clone has been widespread too (15/34; 44.1%). Thirteen of the 34 isolates (38.2%) were positive for the cfr gene. Whole-genome sequencing analysis of relevant LR-MRSE displayed complex resistomes for the presence of several acquired antibiotic resistance genes, including the SCCmec type III (3A) and SCCmec type IV (2B) in ST2 and ST5 isolates, respectively. Bioinformatics and polymerase chain reaction (PCR) mapping also showed a plasmid-location of the cfr gene and the occurrence of previously undetected mutations in L3 (ST2 lineage) and L4 (ST3 lineage) ribosomal proteins and substitutions in the rpoB gene. CONCLUSION: The occurrence of LR-MRSE should be carefully monitored in order to prevent the spread of this difficult-to-treat pathogen and to preserve the efficacy of linezolid.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Linezolida/farmacologia , Staphylococcus epidermidis/genética , Staphylococcus aureus Resistente à Meticilina/genética , Proteína 1 Semelhante a Receptor de Interleucina-1 , Resistência a Meticilina , Estudos Retrospectivos , Infecções Estafilocócicas/epidemiologia , Hospitais , ItáliaRESUMO
Staphylococci are well-known opportunistic pathogens associated with suppurative diseases in humans and animals. Antimicrobial resistance is an emergent threat to humans and animals worldwide. This study investigated the prevalence of methicillin-resistant Staphylococcus spp. (MRS) in hospitalized horses and contacting personnel (veterinarians and staff), and assessed possible interspecies transmission in a teaching veterinary hospital. Nasal swabs from horses (n = 131) and humans (n = 35) were collected. The microorganisms were identified by traditional biochemical tests and genotypic methods, i.e., PCR, internal transcript spacer PCR (ITS-PCR), and gene sequencing. Staphylococcal species were isolated in 18% (23/131) of the horses, of which 8% (11/131) were S. hyicus, 4 % (5/131) were S. aureus, 4% (5/131) were S. pseudintermedius, and 2% (2/131) were S. schleiferi subsp. coagulans. The mecA gene was detected in an S. pseudintermedius isolate. Staphylococcus spp. was isolated in 40% (14/35) of the human samples, all of which were S. aureus. In four samples of S. aureus, the clonal profile ST398 was identified; among them, a clonal similarity of 98.1% was observed between a horse and a contacting human. This finding supports the need for biosecurity measures to avoid the spread of multidrug-resistant staphylococci in humans and horses.
Assuntos
Doenças dos Cavalos , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Cavalos , Animais , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Staphylococcus aureus , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/veterinária , Resistência a Meticilina , Hospitais Veterinários , Staphylococcus/genética , Doenças dos Cavalos/epidemiologiaRESUMO
Background: Staphylococcus aureus is a human pathogen responsible for high mortality rates. The development of new antimicrobials is urgent. Materials & methods: The authors evaluated the activity of hydralazine along with its synergism with other drugs and action on biofilms. With regard to action mechanisms, the authors evaluated cell viability, DNA damage and molecular docking. Results: MIC and minimum bactericidal concentration values ranged from 128 to 2048 µg/ml. There was synergism with oxacillin (50%) and vancomycin (25%). Hydralazine reduced the viability of biofilms by 50%. After exposure to hydralazine 2× MIC, 58.78% of the cells were unviable, 62.07% were TUNEL positive and 27.03% presented damage in the comet assay (p < 0.05). Hydralazine showed affinity for DNA gyrase and TyrRS. Conclusion: Hydralazine is a potential antibacterial.
Staphylococcus aureus is a bacterium that can cause infection. Infections of S. aureus are becoming difficult to treat, but developing new drugs is a challenge. Repurposing them may be easier. This study looks at the possibility of using hydralazine, a type of medicine used to treat high blood pressure, against S. aureus. The authors found that hydralazine can kill S. aureus and can be used with other antibiotics, including oxacillin and vancomycin. Hydralazine interferes with important processes for the multiplication and survival of this bacterium. These results are preliminary but encouraging. Further studies are needed to confirm the use of hydralazine as a new treatment for S. aureus infections.
Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Meticilina , Resistência a Meticilina , Simulação de Acoplamento Molecular , Antibacterianos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Testes de Sensibilidade MicrobianaRESUMO
In northern Australia, a region with limited access to healthcare and a substantial population living remotely, antibiotic resistance adds to the complexity of treating infections. Focussing on Escherichia coli urinary tract infections (UTIs) and Staphylococcus aureus skin & soft tissue infections (SSTIs) captured by a northern Australian antibiotic resistance surveillance system, we used logistic regression to investigate predictors of a subsequent resistant isolate during the same infection episode. We also investigated predictors of recurrent infection. Our analysis included 98,651 E. coli isolates and 121,755 S. aureus isolates from 70,851 patients between January 2007 and June 2020. Following an initially susceptible E. coli UTI, subsequent recovery of a cefazolin (8%) or ampicillin (13%) -resistant isolate during the same infection episode was more common than a ceftriaxone-resistant isolate (2%). For an initially susceptible S. aureus SSTI, subsequent recovery of a methicillin-resistant isolate (8%) was more common than a trimethoprim-sulfamethoxazole-resistant isolate (2%). For UTIs and SSTIs, prior infection with a resistant pathogen was a strong predictor of both recurrent infection and resistance in future infection episodes. This multi-centre study demonstrates an association between antibiotic resistance and an increased likelihood of recurrent infection. Particularly in remote areas, a patient's past antibiograms should guide current treatment choices since recurrent infection will most likely be at least as resistant as previous infection episodes. Using population-level surveillance data in this way can also help clinicians decide if they should switch antibiotics for patients with ongoing symptoms, while waiting for diagnostic results.
Assuntos
Infecções Estafilocócicas , Infecções Urinárias , Humanos , Staphylococcus aureus , Escherichia coli , Reinfecção/tratamento farmacológico , Austrália , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Resistência a Meticilina , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , Testes de Sensibilidade MicrobianaRESUMO
Herein we report a new library of 2,3-pyrrolidinedione analogues that expands on our previous report on the antimicrobial studies of this heterocyclic scaffold. The novel 2,3-pyrrolidinediones reported herein have been evaluated against S. aureus and methicillin-resistant S. aureus (MRSA) biofilms, and this work constitutes our first report on the antibiofilm properties of this class of compounds. The antibiofilm activity of these 2,3-pyrrolidinediones has been assessed through minimum biofilm eradication concentration (MBEC) and minimum biofilm inhibition concentration (MBIC) assays. The compounds displayed antibiofilm properties and represent intriguing scaffolds for further optimization and development.