RESUMEN

AIMS: The antibacterial activity of red propolis extract (RPE) and brown propolis extracts (BPE) and the synergistic effect of RPE with cefoxitin (CEFO), imipenem (IMI), and ertapenem (ERTA) was evaluated in vitro against methicillin-resistant Staphylococcus aureus (MRSA) strains. METHODS AND RESULTS: MRSA ATCC 33591, community-associated (CA-MRSA) USA300, and four clinical isolates were used. A broth microdilution assay was performed to obtain inhibitory and bactericidal concentrations of BPE, RPE, CEFO, IMI, and ERTA. RPE in combination with CEFO, IMI, and ERTA was evaluated on the formation or eradication of biofilm. The bacterial relative membrane conductivity of the strains was assessed after RPE and combinations exposition. Surface/binding computational analyzes between RPE compounds and penicillin binding protein 2a (PBP2a) were performed. BPE samples had no activity against MRSA (MICs 3.2-5 g l-1; MBCs 10-15 g l-1), so the subsequent assays were carried out only with RPE and antimicrobials. RPE exerted a bacteriostatic action (MICs 0.0156-0.125 g l-1; MBCs 0.5-2 g l-1) but the combinations with IMI and ERTA showed the highest inhibition, as observed in the time-kill curve. However, the FICI index showed synergism (≥0.5) only to RPE + IMI. This combination was the most effective in inhibiting the biofilm and showed the highest values of membrane conductivity. Computational predictions indicated that RPE constituents may interact with PBP2a. CONCLUSION: RPE and RPE + IMI exerted an antibacterial and antibiofilm activity on MRSA strains probably due to membrane/wall damage and interactions with PBP2a.

Asunto(s)

Staphylococcus aureus Resistente a Meticilina , Própolis , beta-Lactamas/farmacología , Própolis/farmacología , Brasil , Sinergismo Farmacológico , Antibacterianos/farmacología , Antibacterianos/metabolismo , Cefoxitina/metabolismo , Cefoxitina/farmacología , Imipenem/farmacología , Pruebas de Sensibilidad Microbiana

RESUMEN

The presence of Staphylococcus spp. resistant to methicillin in the nasal cavity of swine has been previously reported. Considering the possible occurrence of bacterial resistance and presence of resistance genes in intensive swine breeding and the known transmissibility and dispersion potential of such genes, this study aimed to investigate the prevalence of resistance to different antibiotics and the presence of the mecA resistance gene in Staphylococcus spp. from piglets recently housed in a nursery. For this, 60 nasal swabs were collected from piglets at the time of their housing in the nursery, and then Staphylococcus spp. were isolated and identified in coagulase-positive (CoPS) and coagulase-negative (CoNS) isolates. These isolates were subjected to the disk-diffusion test to evaluate the bacterial resistance profile and then subjected to molecular identification of Staphylococcus aureus and analyses of the mecA gene through polymerase chain reaction. Of the 60 samples collected, 60 Staphylococcus spp. were isolated, of which 38 (63.33%) were classified as CoNS and 22 (36.67%) as CoPS. Of these, ten (45.45%) were identified as Staphylococcus aureus. The resistance profile of these isolates showed high resistance to different antibiotics, with 100% of the isolates resistant to chloramphenicol, clindamycin, and erythromycin, 98.33% resistant to doxycycline, 95% resistant to oxacillin, and 85% resistant to cefoxitin. Regarding the mecA gene, 27 (45%) samples were positive for the presence of this gene, and three (11.11%) were phenotypically sensitive to oxacillin and cefoxitin. This finding highlights the importance of researching the phenotypic profile of resistance to different antimicrobials and resistance genes in the different phases of pig rearing to identify the real risk of these isolates from a One Health perspective. The present study revealed the presence of samples resistant to different antibiotics in recently weaned production animal that had not been markedly exposed to antimicrobials as growth promoters or even as prophylactics. This information highlights the need for more research on the possible sharing of bacteria between sows and piglets, the environmental pressure within production environments, and the exposure of handlers during their transport, especially considering the community, hospital, and political importance of the presence of circulating resistant strains.

Asunto(s)

Infecciones Estafilocócicas , Enfermedades de los Porcinos , Animales , Porcinos , Femenino , Cefoxitina , Coagulasa , Cavidad Nasal/química , Proteínas Bacterianas/genética , Proteínas de Unión a las Penicilinas/genética , Pruebas de Sensibilidad Microbiana/veterinaria , Antibacterianos/farmacología , Oxacilina , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus/genética , Staphylococcus/genética , Enfermedades de los Porcinos/microbiología

RESUMEN

Staphylococcus spp. and Mammaliicoccus spp. colonize the skin and mucosa of humans and other animals and are responsible for several opportunistic infections. Staphylococci antibiotic resistance may be present in the environment due to the spread of treated and untreated manure from the livestock industry due to antibiotic use to disease control or growth promoter. In this work, we analyzed the species distribution and antimicrobial susceptibility of Staphylococcus and Mammaliicoccus species along different sites of a swine manure treatment plant from Southeastern Brazil. Bacterial colonies were obtained on mannitol salt agar, selected after catalase test and Gram staining, and finally identified by mass spectrometry and sequencing of the tuf gene. According to the results, S.cohnii and S. simulans were the most prevalent species. Antibiotic resistance test revealed that several strains were resistant to multiple drugs, with high levels of chloramphenicol resistance (98%), followed by erythromycin (79%), tetracycline (73%), gentamicin (46%), ciprofloxacin (42%), cefoxitin (18%), sulfamethoxazole + trimethoprim (12%), and linezolid (4%). In addition, gene detection by PCR showed that all strains carried at least 2 resistance genes and one of them carried all 11 genes investigated. Using the GTG5-PCR approach, a high genetic similarity was observed between some strains that were isolated from different points of the treatment plant. Although some were seemingly identical, differences in their resistance phenotype and genotype suggest horizontal gene transfer. The presence of resistant bacteria and resistance genes along the treatment system highlights the potential risk of contamination by people in direct contact with these animals and the soil since the effluent is used as a biofertilizer in the surrounding environment.

Asunto(s)

Antibacterianos , Staphylococcus , Humanos , Porcinos , Animales , Antibacterianos/farmacología , Estiércol , Farmacorresistencia Bacteriana/genética , Cefoxitina , Pruebas de Sensibilidad Microbiana

RESUMEN

Introduction: The aim of this study was to investigate the prevalence and distribution of AmpC beta-lactamases (BLs) in uropathogens (E. coli and K. pneumoniae) at the University Hospital of the West Indies Jamaica (UHWI). Method: De-duplicated consecutive urine samples, collected from January to March 2020 at the UHWI, were analyzed. Screening and phenotypic confirmatory tests were conducted using resistance to cefoxitin and the Disc Approximation Test (DAT) respectively, for isolates of interest. Multiplex PCR was performed on cefoxitin resistant (CR) isolates for the detection of bla CIT, bla MOX, bla FOX, bla ACC, and bla DHA genes. Whole genome sequencing (WGS) was used to further detect AmpC BL genes in PCR negative isolates with indeterminate phenotypic results. Results: Sixty-four Gram negative isolates were obtained from 61 patients (55% female), aged 18 months to 88 years old. At least 35% (26) had complicated urinary tract infections. Only 7 out of 64 isolates were E. coli or K. pneumoniae, had antibiograms suggestive of possible AmpC BL production and were CR. DATs confirmed AmpC BL in two of these (1 K. pneumoniae; 1 E. coli), one tested negative (E. coli) and four had inconclusive results (K. pneumoniae). PCR detected bla DHA and bla CIT in two CR isolates. WGS further detected bla CMY-42 in one isolate. The prevalence of screened CR isolates with AmpC BL is 57.14% (4 of 7), representing 6.25% of the sample. AmpC BL producers tested had 100% susceptibility to meropenem and nitrofurantoin. Conclusion: AmpC BL prevalence among E. coli and K. pneumoniae, common urinary pathogens, in the studied isolates is low. Although cefoxitin screening is helpful, phenotypic screening using the DAT can yield indeterminate results best clarified by molecular testing.

Asunto(s)

Escherichia coli , Klebsiella pneumoniae , Humanos , Femenino , Masculino , Klebsiella pneumoniae/genética , Escherichia coli/genética , Cefoxitina/farmacología , Prevalencia , Centros de Atención Terciaria , Antibacterianos/farmacología , beta-Lactamasas/genética , Proteínas Bacterianas/genética , Pruebas de Sensibilidad Microbiana

RESUMEN

BACKGROUND: Staphylococcus aureus and Streptococcus agalactiae are the main cause of clinical mastitis in dairy cattle in Argentina, whereas coagulase-negative staphylococci (CNS) and environmental streptococci are the main cause of subclinical mastitis. Bacteria isolated from infected animals show increasing antimicrobial resistance. OBJECTIVES: This study aims to determine the antimicrobial resistance of staphylococci and streptococci isolated from milk with mastitis, and to genotypically characterize the methicillin-resistant (MR) staphylococci. METHODS: Isolation was performed on blood agar and identification was based on biochemical reactions. Antimicrobial susceptibility was according to the Clinical and Laboratory Standards Institute guidelines. The antimicrobial resistance genes, SCCmec type and spa type were detected by the polymerase chain reaction method. RESULTS: We isolated a total of 185 staphylococci and 28 streptococci from 148 milk samples. Among the staphylococcal isolates, 154 were identified as CNS and 31 as S. aureus. Among the 154 CNS, 24.6% (n = 38) were resistant to penicillin, 14.9% (n = 23) to erythromycin, 17.5% (n = 27) to clindamycin, 6.5% (n = 10) to cefoxitin and oxacillin. Among the S. aureus isolates, 16.1% (n = 5) were resistant to penicillin, 3.2% (n = 1) to cefoxitin and oxacillin (MRSA). Six MR isolates (5 CNS and 1 MRSA) were positive to the mecA gene, and presented the SCCmec IVa. The MRSA strain presented the sequence type 83 and the spa type 002. Among the 28 streptococcal isolates, 14.3% (n = 4) were resistant to penicillin, 10.7% (n = 3) to erythromycin and 14.3% (n = 4) to clindamycin. CONCLUSIONS: The present findings of this study indicate a development of antimicrobial resistance in main bacteria isolated from cows with mastitis in Argentina.

Asunto(s)

Enfermedades de los Bovinos , Mastitis Bovina , Femenino , Bovinos , Animales , Staphylococcus , Antibacterianos/farmacología , Staphylococcus aureus , Cefoxitina , Clindamicina , Argentina/epidemiología , Farmacorresistencia Bacteriana , Mastitis Bovina/epidemiología , Streptococcus , Oxacilina , Eritromicina

RESUMEN

INTRODUCTION: The occurrence of methicillin-resistant Staphylococcus aureus (MRSA) in pets and their owners has increased due to the misuse and abuse of antibiotics. This study compared the prevalence of MRSA and Staphylococcus aureus strains in pets and their owners in urban and rural communities in Trinidad. METHODOLOGY: Questionnaires were administered to gather demographic and risk factor data for MRSA for human participants, and their pets. Nasal swabs were obtained from 100 pets (dogs and cats) and their human owners. For the isolation of MRSA, nasal swabs obtained were enriched and then plated on selective media. Staphylococcus aureus was identified using standard biochemical procedures. The resistance of S. aureus initially assessed detection of MRSA isolates to cefoxitin and confirmed by the PBP2a latex agglutination test. Antibiotic resistance was determined using the disc diffusion method. RESULTS: The prevalence of MRSA was 6.0% (3/50) and 2.0% (1/50) in household pet animals and their owners, respectively in urban communities, while in rural communities, the prevalence was 6.0% (3/50) and 12.0% (6/50) respectively. The prevalence of S. aureus in pet owners was higher in the rural community (44.0%) compared to urban (30.0%). However, in pet animals, S. aureus was more frequently isolated from urban communities (78.0%) than rural ones (66.0%). Amongst the S. aureus isolates, 81.7% were resistant to one or more antimicrobial agents. CONCLUSIONS: This study has demonstrated that living in a rural community increased the odds of MRSA colonization.

Asunto(s)

Enfermedades de los Gatos , Enfermedades de los Perros , Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Animales , Antibacterianos/farmacología , Gatos , Cefoxitina , Perros , Humanos , Pruebas de Sensibilidad Microbiana , Mascotas , Población Rural , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/veterinaria , Staphylococcus aureus , Trinidad y Tobago/epidemiología

RESUMEN

The aim of this study was to characterize phenotypically and genotypically 27 mecA positive Staphylococcus aureus strains with oxacillin MICs of ≤2µg/ml by Vitek 2, isolated in different regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient diffusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined. SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolates were susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3 strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in 25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strains carried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did not belong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26 of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carrying SCCmec V.

Asunto(s)

Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Humanos , Oxacilina/farmacología , Staphylococcus aureus , Cefoxitina/farmacología , Uruguay , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus Resistente a Meticilina/genética

RESUMEN

ABSTRACT: Here we characterized the distribution and the antibiotic resistance of staphylococci from a Brazilian pork production chain. Samples (n = 1,114) from pig farms, pig lots, and slaughterhouses, located in two Brazilian states (Minas Gerais and Paraná), were subjected to coagulase-positive Staphylococcus enumeration. S. aureus isolates (n = 251) from this collection were further characterized for their resistance to oxacillin, cefoxitin, vancomycin, and tetracycline through phenotypic and molecular assays. Coagulase-positive Staphylococcus counts from pig farms were higher compared with other samples (P < 0.05). Other counts were relatively low but were present in all production stages. S. aureus isolates were commonly resistant to oxacillin and cefoxitin (54 of 73, 74.0%), qualifying them as methicillin-resistant S. aureus, but PCR assays indicated that few harbored the expected antimicrobial resistance genes (femB, mecA, and mecC). Lower frequencies of vancomycin and tetracycline resistance were found (6.8 to 37.0%). PCR sensitivity (34.5 to 86.7%) and specificity (26.6 to 85.0%) for detection of antibiotic resistance genes varied based on the assessed antibiotic. Antibiotic-resistant staphylococci are widely distributed in the Brazilian pork production chain, and methicillin-resistant S. aureus can become a potential health and economic impediment for the Brazilian pork industry.

Asunto(s)

Staphylococcus aureus Resistente a Meticilina , Carne de Cerdo , Carne Roja , Infecciones Estafilocócicas , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Brasil/epidemiología , Cefoxitina , Coagulasa , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacología , Infecciones Estafilocócicas/epidemiología , Staphylococcus , Staphylococcus aureus , Porcinos , Vancomicina

RESUMEN

BACKGROUND: The increasing and inappropriate use of antibiotics has increased the number of multidrug-resistant microorganisms to these drugs, causing the emergence of infections that are difficult to control and manage by health professionals. As an alternative to combat these pathogens, some monoterpenes have harmful effects on the bacterial cell membrane, showing themselves as an alternative in combating microorganisms. Therefore, the positive enantiomer α -pinene becomes an alternative to fight bacteria, since it was able to inhibit the growth of the species Escherichia coli ATCC 25922, demonstrating the possibility of its use as an isolated antimicrobial or associated with other drugs. AIMS: The aim of this study is to evaluate the sensitivity profile of E. coli ATCC 25922 strain against clinical antimicrobials associated with (+) -α-pinene and how it behaves after successive exposures to subinhibitory concentrations of the phytochemicals. METHODS: The minimum inhibitory concentration (MIC) was determined using the microdilution method. The study of the modulating effect of (+) -α-pinene on the activity of antibiotics for clinical use in strains of E. coli and the analysis of the strain's adaptation to the monoterpene were tested using the adapted disk-diffusion method. RESULTS: The results demonstrate that the association of monoterpene with the antimicrobials ceftazidime, amoxicillin, cefepime, cefoxitin and amikacin is positive since it leads to the potentiation of the antibiotic effect of these compounds. It was observed that the monoterpene was able to induce crossresistance only for antimicrobials: cefuroxime, ceftazidime, cefepime and chloramphenicol. CONCLUSION: It is necessary to obtain more concrete data for the safe use of these combinations, paying attention to the existence of some type of existing toxicity reaction related to the herbal medicine and to understand the resistance mechanisms acquired by the microorganism.

Asunto(s)

Antibacterianos/farmacología , Monoterpenos Bicíclicos/farmacología , Escherichia coli/efectos de los fármacos , Amicacina/química , Amicacina/farmacología , Amoxicilina/química , Amoxicilina/farmacología , Antibacterianos/química , Monoterpenos Bicíclicos/química , Cefepima/química , Cefepima/farmacología , Cefoxitina/química , Cefoxitina/farmacología , Ceftazidima/química , Ceftazidima/farmacología , Pruebas de Sensibilidad Microbiana

RESUMEN

The penicillin-binding proteins (PBPs) are important biological target for new antibacterial drugs development. This study focused on molecular interaction between cefoxitin and the Escherichia coli PBP5 by molecular dynamics (MD) using hybrid quantum mechanics/molecular mechanics (QM/MM) simulations approach, searching to develop a computational simulations prototype method on antimicrobial susceptibility of gram-negative bacteria against antibiotics. Escherichia coliATCC 8739 strain susceptibility for the drugs used in the antimicrobial susceptibility testing and selection of bioactive molecules against resistant strain. The protonation revealed a deprotonate state for His146, His151, His216, and His320 residues. The complex was stabilized after 0.6 ns of MD simulation. The global interaction means for inhibition zone diameters of E. coliATCC8739 strain and cefoxitin were 24.33 mm no showing significant difference between computational and experimental methods. Our computational simulation method can reliably be performed as a molecular modeling prototype for gram-negative antimicrobial susceptibility testing bacteria.

Asunto(s)

Antibacterianos/química , Cefoxitina/química , Proteínas de Escherichia coli/química , Bacterias Gramnegativas/efectos de los fármacos , Antibacterianos/farmacología , Cefoxitina/farmacología , Pruebas de Sensibilidad Microbiana , Simulación de Dinámica Molecular , Teoría Cuántica

RESUMEN

Introduction: Infections associated with health care caused by S. aureus and coagulase-negative Staphylococci multi-resistant to antibiotics cause a high epidemiological impact due to their high morbidity and mortality. Biofilm formation, which has been associated with antimicrobial resistance, can also occur. Objectives: To determine methicillin resistance and to quantify the biofilm production to establish if there is a relationship in clinical isolates of S. aureus and coagulase-negative Staphylococci. Material and methods: A total of 11 strains of S. aureus and 12 of coagulase-negative Staphylococci were studied. Methicillin resistance was determined with cefoxitin discs and the Clinical Laboratory Standards Institute (CSLI), 2018 reference values. Biofilm production was quantified by the crystal violet method. The mecA and icaADBC genes were identified by PCR. A bivariate analysis was performed with chi-square (c2) and Cramér's V statistical tests, using SPSS™, version 20.0 software. Results: Nine S. aureus strains were methicillin-resistant and two were sensitive. Eight coagulase-negative Staphylococci strains were resistant and four were sensitive. The mecA genotype was found in eight of the nine S. aureus resistant strains and six of eight resistant coagulase-negative Staphylococci. All strains formed biofilms. Ten strains of S. aureus and 11 of coagulase-negative Staphylococci presented the icaADCB genotype. No association was found between methicillin-resistance and biofilm formation. Conclusions: Cefoxitin is enough to define the resistance phenotype and is associated with the mecA genotype. All strains formed biofilms and were related to the presence of the icaADCB operon. Biofilm formation and methicillin resistance were independent features in both groups of strains.

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Introducción. Las infecciones por Staphylococcus aureus y Staphylococcus coagulasa negativa multirresistentes a los antibióticos y asociadas con la atención en salud tienen un gran impacto epidemiológico por su alta morbimortalidad; además, se han relacionado con la formación de biopelículas, lo cual también se asocia con la resistencia a los antimicrobianos. Objetivo. Determinar la resistencia a la meticilina y cuantificar la producción de biopelículas para establecer su posible relación con los aislamientos clínicos de S. aureus y Staphylococcus coagulasa negativa. Materiales y métodos. Se estudiaron 11 cepas de S. aureus y 12 de Staphylococcus coagulasa negativa. La resistencia a la meticilina se determinó con discos de cefoxitina tomando como valores de referencia los estándares del Clinical Laboratory Standards Institute (CLSI) de 2018. La producción de biopelícula se cuantificó con cristal violeta. Los genes mecA e icaADBC se identificaron mediante reacción en cadena de la polimerasa (PCR), y se hizo un análisis bivariado con la prueba de ji al cuadrado y el coeficiente V de Cramér, utilizando el programa SPSS™, versión 20.0. Resultados. Nueve cepas de S. aureus fueron resistentes a la meticilina (SARM) y dos fueron sensibles. Ocho cepas de Staphylococcus coagulasa negativa fueron resistentes y cuatro fueron sensibles. El genotipo mecA se encontró en ocho de las nueve cepas de S. aureus y en seis de las ocho de Staphylococcus coagulasa negativa resistentes a meticilina. Todas las cepas formaron biopelícula. Diez cepas de S. aureus y 11 de Staphylococcus coagulasa negativa presentaron el genotipo icaADCB. No se encontró asociación entre la resistencia a meticilina y la formación de biopelícula. Conclusiones. La cefoxitina es suficiente para determinar el fenotipo resistente a meticilina y se asoció con el genotipo mecA. Las cepas resistentes a la meticilina y poseedoras del gen mecA pueden presentar un mecanismo de resistencia alterno. Los dos grupos de cepas formadoras de biopelícula se relacionaron con la presencia del operón icaADCB. La formación de biopelícula y la resistencia a la meticilina se expresaron como características independientes en los dos grupos de cepas.

Asunto(s)

Biopelículas/crecimiento & desarrollo , Resistencia a la Meticilina , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Staphylococcus/efectos de los fármacos , Staphylococcus/fisiología , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Cefoxitina/farmacología , Coagulasa , ADN Bacteriano/aislamiento & purificación , Genes Bacterianos , Humanos , Resistencia a la Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , México , Pruebas de Sensibilidad Microbiana/métodos , Oxacilina/farmacología , Proteínas de Unión a las Penicilinas/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus/enzimología , Staphylococcus/genética , Staphylococcus aureus/genética

RESUMEN

Resumen Introducción. Las infecciones por Staphylococcus aureus y Staphylococcus coagulasa negativa multirresistentes a los antibióticos y asociadas con la atención en salud tienen un gran impacto epidemiológico por su alta morbimortalidad; además, se han relacionado con la formación de biopelículas, lo cual también se asocia con la resistencia a los antimicrobianos. Objetivo. Determinar la resistencia a la meticilina y cuantificar la producción de biopelículas para establecer su posible relación con los aislamientos clínicos de S. aureus y Staphylococcus coagulasa negativa. Materiales y métodos. Se estudiaron 11 cepas de S. aureus y 12 de Staphylococcus coagulasa negativa. La resistencia a la meticilina se determinó con discos de cefoxitina tomando como valores de referencia los estándares del Clinical Laboratory Standards Institute (CLSI) de 2018. La producción de biopelícula se cuantificó con cristal violeta. Los genes mecA e icaADBC se identificaron mediante reacción en cadena de la polimerasa (PCR), y se hizo un análisis bivariado con la prueba de ji al cuadrado y el coeficiente V de Cramér, utilizando el programa SPSS™, versión 20.0. Resultados. Nueve cepas de S. aureus fueron resistentes a la meticilina (SARM) y dos fueron sensibles. Ocho cepas de Staphylococcus coagulasa negativa fueron resistentes y cuatro fueron sensibles. El genotipo mecA se encontró en ocho de las nueve cepas de S. aureus y en seis de las ocho de Staphylococcus coagulasa negativa resistentes a meticilina. Todas las cepas formaron biopelícula. Diez cepas de S. aureus y 11 de Staphylococcus coagulasa negativa presentaron el genotipo icaADCB. No se encontró asociación entre la resistencia a meticilina y la formación de biopelícula. Conclusiones. La cefoxitina es suficiente para determinar el fenotipo resistente a meticilina y se asoció con el genotipo mecA. Las cepas resistentes a la meticilina y poseedoras del gen mecA pueden presentar un mecanismo de resistencia alterno. Los dos grupos de cepas formadoras de biopelícula se relacionaron con la presencia del operón icaADCB. La formación de biopelícula y la resistencia a la meticilina se expresaron como características independientes en los dos grupos de cepas.

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Abstract Introduction: Infections associated with health care caused by S. aureus and coagulase- negative Staphylococci multi-resistant to antibiotics cause a high epidemiological impact due to their high morbidity and mortality. Biofilm formation, which has been associated with antimicrobial resistance, can also occur. Objectives: To determine methicillin resistance and to quantify the biofilm production to establish if there is a relationship in clinical isolates of S. aureus and coagulase-negative Staphylococci. Material and methods: A total of 11 strains of S. aureus and 12 of coagulase-negative Staphylococci were studied. Methicillin resistance was determined with cefoxitin discs and the Clinical Laboratory Standards Institute (CSLI), 2018 reference values. Biofilm production was quantified by the crystal violet method. The mecA and icaADBC genes were identified by PCR. A bivariate analysis was performed with chi-square (c2) and Cramér's V statistical tests, using SPSS™, version 20.0 software. Results: Nine S. aureus strains were methicillin-resistant and two were sensitive. Eight coagulase-negative Staphylococci strains were resistant and four were sensitive. The mecA genotype was found in eight of the nine S. aureus resistant strains and six of eight resistant coagulase-negative Staphylococci. All strains formed biofilms. Ten strains of S. aureus and 11 of coagulase-negative Staphylococci presented the icaADCB genotype. No association was found between methicillin-resistance and biofilm formation. Conclusions: Cefoxitin is enough to define the resistance phenotype and is associated with the mecA genotype. All strains formed biofilms and were related to the presence of the icaADCB operon. Biofilm formation and methicillin resistance were independent features in both groups of strains.

Asunto(s)

Humanos , Staphylococcus/efectos de los fármacos , Staphylococcus/fisiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Resistencia a la Meticilina , Biopelículas/crecimiento & desarrollo , Oxacilina/farmacología , Infecciones Estafilocócicas/microbiología , Staphylococcus/enzimología , Staphylococcus/genética , Staphylococcus aureus/genética , Proteínas Bacterianas/genética , ADN Bacteriano/aislamiento & purificación , Pruebas de Sensibilidad Microbiana/métodos , Cefoxitina/farmacología , Resistencia a la Meticilina/genética , Coagulasa , Proteínas de Unión a las Penicilinas/genética , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Genes Bacterianos , México , Antibacterianos/farmacología

RESUMEN

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is a cause of zoonotic infections in many countries. People with occupational contact with food animal production are at risk of colonization. The aim of this study was to determine the prevalence of MRSA and their frequency of resistance to other antimicrobial agents from broilers and workers at the 'pluck shops' in Trinidad. For isolation of MRSA, choanal, cloacal and pharyngeal swabs taken from broilers and nasal swabs from humans were enriched then plated on CHROMagar MRSA and Brilliance MRSA. MRSA was confirmed using the PBP2a test kit, resistance to oxacillin and cefoxitin and polymerase chain reaction (PCR) for the mecA gene. Antimicrobial resistance of the MRSA isolates to 16 antimicrobial agents was determined using the disc diffusion method. Of the 287 broilers and 47 humans sampled, MRSA was isolated at a frequency of 2 (0.7%) and 0 (0.0%) respectively. All the MRSA isolates exhibited resistance to one or more of the 16 antimicrobial agents. The study demonstrated that broilers at 'pluck shops' in Trinidad harbor MRSA. This is the first isolation of MRSA from poultry in Trinidad, West Indies, and this finding is of public health significance since occupational exposure of humans can lead to increased risk of acquiring MRSA infections.

Asunto(s)

Pollos/microbiología , Farmacorresistencia Bacteriana Múltiple , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Mucosa Nasal/microbiología , Exposición Profesional/análisis , Animales , Antibacterianos , Cefoxitina , Estudios Transversales , Humanos , Ganado , Meticilina , Pruebas de Sensibilidad Microbiana , Oxacilina , Reacción en Cadena de la Polimerasa , Prevalencia , Serogrupo , Infecciones Estafilocócicas/epidemiología , Trinidad y Tobago/epidemiología

RESUMEN

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

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Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Asunto(s)

Animales , Perros , Oxacilina , Staphylococcus/genética , Staphylococcus aureus , Infecciones Cutáneas Estafilocócicas/veterinaria , Cefoxitina , Resistencia a las Cefalosporinas , Perros/microbiología , Dermatitis/veterinaria , Pruebas Antimicrobianas de Difusión por Disco/veterinaria , Foliculitis/veterinaria

RESUMEN

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)

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Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)

Asunto(s)

Animales , Perros , Oxacilina , Staphylococcus/genética , Staphylococcus aureus , Infecciones Cutáneas Estafilocócicas/veterinaria , Cefoxitina , Resistencia a las Cefalosporinas , Perros/microbiología , Dermatitis/veterinaria , Pruebas Antimicrobianas de Difusión por Disco/veterinaria , Foliculitis/veterinaria

RESUMEN

This work aimed to investigate the prevalence of Staphylococcus in wild birds seized in illegal trade and their antimicrobial resistance patterns. Cloacal samples were obtained from 109 wild birds apprehended in the street markets in Rio de Janeiro, Brazil. Staphylococcus spp. were phenotypically and genotypically identified, and resistance profile was evaluated according to Clinical and Laboratory Standards Institute guidelines and by polymerase chain reaction of mecA and blaZ genes. Staphylococcus was detected in 45·9% (50/109) of the cloacal swab samples, and 39 (78·0%) isolates were resistant to one or more of the nine antimicrobials tested and were also positive to mecA (12/39) or blaZ genes (14/39). High percentage of resistance was detected to ampicillin, oxacillin, cefoxitin, clindamycin and tetracycline, with the absence of resistance to vancomycin. Wild birds captured and submitted to captive stress conditions of illegal trade market of Brazil may have an important role as reservoirs of Staphylococcus spp. and its antimicrobial resistance mechanisms. The significance of this study is revealed by the zoonotic and pathogenic potential of staphylococci and that impact to public health and requires monitoring polices of wild birds health in tropical areas. SIGNIFICANCE AND IMPACT OF THE STUDY: The isolation of Staphylococcus species that are not commonly isolated from wild bird faeces, the relatively high proportion of strains showing degrees of resistance to ß-lactamics, lincosamides and tetracycline, and also the presence of mecA and blaZ genes that has been associated with multidrug phenotype reveal its public health relevance and zoonotic potential. Consequently, this represents an important route to transmission of this pathogen and its antimicrobial resistance mechanisms throughout national and international frontiers fostered by the illegal trade of wild animals and close contact with humans.

Asunto(s)

Animales Salvajes/microbiología , Aves/microbiología , Staphylococcus/aislamiento & purificación , Animales , Antibacterianos/farmacología , Brasil/epidemiología , Cefoxitina/farmacología , Farmacorresistencia Bacteriana , Humanos , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacología , Salud Pública/economía , Staphylococcus/clasificación , Staphylococcus/efectos de los fármacos , Staphylococcus/genética

RESUMEN

AIM: To evaluate the adequacy of the disc-diffusion test and E-test® compared with detection of mecA for coagulase-negative staphylococci isolated from blood cultures, nasal swabs and wounds. RESULTS: Agreement between all techniques was observed in 65.7% of cases. The greatest discrepancy between mecA/susceptible E-test was observed for non-epidermidis species. A resistance breakpoint ≤19 mm using the oxacillin disc was found to best classify all coagulase-negative staphylococci isolates; Staphylococcus epidermidis, ≤19 mm (oxacillin) and ≤27 mm (cefoxitin); Staphylococcus haemolyticus and Staphylococcus capitis, ≤21 mm (oxacillin) and ≤18 mm (cefoxitin); Staphylococcus warneri, MICs ≥0.75 mg/l. CONCLUSION: Although no longer recommended by the Clinical Laboratory Standards Institute, we observed some cases in which only the oxacillin disc-diffusion test detected resistance. The discrepancy between phenotypic tests and mecA is probably due to heterogeneity and borderline resistance.

Asunto(s)

Antibacterianos/farmacología , Coagulasa/metabolismo , Resistencia a la Meticilina/genética , Oxacilina/farmacología , Staphylococcus/efectos de los fármacos , Proteínas Bacterianas/genética , Cefoxitina/farmacología , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Fenotipo , Valores de Referencia , Staphylococcus/genética , beta-Lactamasas/metabolismo

RESUMEN

The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.

Asunto(s)

Farmacorresistencia Bacteriana Múltiple , Carne/microbiología , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Porcinos/microbiología , Mataderos , Animales , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Cefoxitina/farmacología , Chile/epidemiología , Enterotoxinas/genética , Microbiología de Alimentos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacología , Proteínas de Unión a las Penicilinas/genética , Prevalencia , Infecciones Estafilocócicas/veterinaria

RESUMEN

Cow raw milk cheese is widely eaten in Brazil. These products may be contaminated with pathogenic bacteria. In this work, we investigated the presence of Escherichia coli in raw milk cheese from different States in Brazil. From 147 "Minas" cheese samples, 28 cheeses were positive for E. coli. Among 39 E. coli isolates of the cheeses, one was positive for eae and negative for bpfA and efa1/lifA using PCR, and so was classified as atypical Enteropathogenic E. coli (aEPEC). Two other isolates were positive for extraintestinal pathogenic E. coli (ExPEC) genes. The aEPEC isolate belongs to serogroup O127 and was classified in A phylogenetic group, and ExPEC isolates were found in O73:H12 (EC-2 strain) and O64474:H8 (EC-9 strain) serotype. This ExPEC belongs to A and C phylogenetic group, respectively. Most of E. coli strains belonged to Clermont phylogenetic groups A (28.2%), C, and E (23.1%). Six strains (15.4%) of E. coli were positive for group B1 and two (5.1%) for B2. E. coli isolates presented an aggregative (46.0%) and diffuse (12.6%) adherence pattern to HeLa cells, and the other isolates did not show adhesion (41.4%). Four E. coli isolates (10.3%) were shown to produce moderate biofilm. The antimicrobial resistance rate was tetracycline (25.6%), followed by ampicillin (17.9%), cefoxitin (7.7%), nalidixic acid (5.1%), and amoxicillin-clavulanic acid (2.6%). One strain was resistant to three antimicrobials (tetracycline, ampicillin, and nalidixic acid). The presence of these microorganisms, the O127 strain, and a new serogroup in Brazil is a potential risk for public health.

Asunto(s)

Queso/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli Enteropatógena/genética , Leche/microbiología , Combinación Amoxicilina-Clavulanato de Potasio/farmacología , Ampicilina/farmacología , Animales , Antibacterianos/farmacología , Adhesión Bacteriana , Brasil , Cefoxitina/farmacología , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Escherichia coli Enteropatógena/efectos de los fármacos , Escherichia coli Enteropatógena/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Células HeLa , Humanos , Pruebas de Sensibilidad Microbiana , Ácido Nalidíxico/farmacología , Pasteurización , Filogenia , Serogrupo , Serotipificación , Tetraciclina/farmacología

RESUMEN

Se realizó un estudio prospectivo de 47 cepas de estafilococo procedentes de muestras biológicas del Laboratorio de Microbiología del Hospital Provincial Docente Clinicoquirúrgico Saturnino Lora Torres de Santiago de Cuba, desde febrero hasta abril de 2017, con vistas a determinar la frecuencia de estafilococos resistentes a la meticilina. En la serie, el mayor número de los aislamientos correspondió a las muestras de secreciones y catéter; asimismo, los servicios con mayores aislamientos notificados fueron Ortopedia y Cirugía. Se observó una frecuencia elevada de cepas de Staphylococcus aureus y estafilococo coagulasa negativa, resistentes a meticilina

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A prospective study of 47 staphylococcus stumps coming from biological samples of the Microbiology Laboratory in Saturnino Lora Torres Teaching Clinical Surgical Provincial Hospital was carried out in Santiago de Cuba, from February to April, 2017, aimed at determining the frequency of staphylococcus resistant to methicillin. In the series, the highest number of isolations corresponded to the samples of secretions and catheter; also, the services with more notified isolations were Orthopedics and Surgery. A high frequency of Staphylococcus aureus stumps and negative coagulase staphylococcus resistant to methicillin was observed

Asunto(s)

Humanos , Masculino , Femenino , Staphylococcus aureus , Resistencia a la Meticilina , Farmacorresistencia Bacteriana , Cefoxitina , Estudios Prospectivos